Neurosurgery Practice QnA Flashcards

Question

Which of the following is NOT associated with the findings on this X-ray? A. Weakness of hand intrinsic flexors B. Horner’s syndrome C. Raynaud’s syndrome D. Traction meningocele E. Ulnar paresthesias

Answer 1

A. Weakness of hand intrinsic flexors **B. Horner’s syndrome** C. Raynaud’s syndrome D. Traction meningocele E. Ulnar paresthesias ## Footnote The X-ray shows a cervical rib, usually associated with ulnar nerve weakness and paresthesia, Raynaud’s syndrome, and traction meningocele.

Answer 2

A. Multiple subcutaneous lipomas B. Macrocephaly C. Hemangiomas D. Intracranial arteriovenous malformations **E. Capillary malformation or “port-wine stain** ## Footnote Bannayan–Riley–Ruvalcaba’s syndrome (BRRS) is a rare overgrowth disorder with occurrence of multiple subcutaneous lipomas, macrocephaly, and he- mangiomas. The disease is inherited in an autosomal dominant fashion, but sporadic cases have been seen. The syndrome belongs to a family of hamar- tomatous polyposis syndromes, which includes Peutz–Jeghers’s syndrome, juvenile polyposis, and Cowden disease. Mutation of the PTEN gene is associ- ated with this syndrome, Cowden disease, Proteus syndrome, and Proteus-like syndrome. These four syndromes are referred to as PTEN hamartoma-tumor syndromes. Intracranial arteriovenous malformations represent a rare feature of BRRS. Capillary malformation or “port-wine stain,” is a cutaneous vascular anomaly that initially appears as a red macular stain that darkens over time. It also occurs in several combined vascular anomalies that exhibit hypertrophy, such as Sturge–Weber’s syndrome and Klippel–Trénaunay’s syndrome.

Answer 3

A. Between the claustrum and the putamen **B. Between the claustrum and the insular cortex** C. Between the putamen and the globus pallidus externus D. Between the globus pallidus externus and the globus pallidus internus E. Above the caudate nucleus ## Footnote The external capsule is located between the claustrum and the putamen. The extreme capsule is located between the claustrum and the insular cortex.

Answer 4

A. Serotonin **B. Dopamine** C. Noradrenaline D. All of the above E. None of the above ## Footnote Serotonin pathways inhibit copulation, explaining the side effect of decreased libido with selective serotonin reuptake inhibitors (SSRIs) used to treat depres- sion. Administration of L-dopa increases libido. Noradrenergic receptors in the brain exert an inhibitory effect on penile erection.

Answer 5

A. 4 hours. B. 2 hours. C. 1 hour. D. 30 minutes. **E. 15 minutes** ## Footnote The peak reduction in intracranial pressure (ICP) occurs in about 15 minutes after administration of mannitol. The duration of action of mannitol is about 4 hours due to the rapid renal elimination of the drug. When mannitol is used with furosemide, the combined effect on ICP reduction is greater than if either were used alone.

Answer 6

A. I and II. B. II and III. **C. III and IV** D. IV and V. E. None of the above ## Footnote The paramedial triangle (also known as the supratrochlear triangle) is defined medially by the medial border of the oculomotor nerve and laterally by the lateral border of the trochlear nerve.

Answer 7

The Tensilon test A. is not sensitive but very specifi c for myasthenia gravis (MG). B. is not particularly useful in ocular MG. C. when negative, rules out the diagnosis of MG. **D. shows no correlation with subsequent response to pyridostigmine** E. is not aff ected by the quantity of acetylcholine receptors. ## Footnote The Tensilon test is sensitive in diagnosing a defect in neuromuscular trans- mission but is not specific for myasthenia gravis (MG). The Tensilon test is especially useful in ocular MG, when other diagnostic tests may be negative. Depending on the mechanism of acetylcholine receptor (AchR) antibodies, there may be insufficient numbers of AchRs available so that a negative Tensi- lon test does not negate the diagnosis of MG. There is no correlation between the results of the Tensilon test and the subsequent response to pyridostigmine.

Answer 8

D. extensor carpi ulnaris The posterior interosseous nerve (C7, C8) is a branch of the radial nerve. The posterior interosseous nerve innervates the extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. The extensor carpi ulnaris extends the hand at the wrist joint. This muscle is spared in posterior interosseous syndrome ## Footnote The posterior interosseous nerve (C7, C8) is a branch of the radial nerve. The posterior interosseous nerve innervates the extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. The extensor carpi ulnaris extends the hand at the wrist joint. This muscle is spared in posterior interosseous syndrome.

Answer 9

**B. 2** ## Footnote The magnetic resonance angiography scan (MRA) represents the findings of a left anterior frontal arteriovenous malformation (AVM) of which the nidus measures between 3 and 6 cm, which adds two points in the Spetzler–Martin grading system. It is located in noneloquent brain and has superficial drainage; therefore it is a grade 2 Spetzler–Martin AVM.

Answer 10

**B. Contralateral superior quadrantanopia** ## Footnote Interruption of the inferior geniculocalcarine fibers in the temporal lobe pro- duces a “pie in the sky” deficit (contralateral superior quadrantanopia).

Answer 11

**D. All of the above** ## Footnote Ocular myoclonus is a pendular vertical oscillation of the eyes, usually of large amplitude and often occurring with movements of the palate. It can devel- op months to years after bilateral destructive lesions of the central tegmental tract and is often accompanied by bilateral horizontal gaze palsies and is asso- ciated with hypertrophy of the inferior olivary nucleus.

Answer 12

**A. Late hypoxemia** B. Diffuse infiltrate C. Leaky capillaries D. Association with sepsis and trauma E. Protein content of fluid greater than with pulmonary edema ## Footnote Early hypoxemia characterizes ARDS.

Answer 13

A. 2 weeks. B. 4 weeks. **C. 6 weeks.** D. 8 weeks. E. 10 weeks. ## Footnote Maximum collagen deposition occurs at 42 days (about 6 weeks). Tensile strength keeps on increasing until 2 years.

Answer 14

A. It is histologically characterized by a biphasic pattern. **B. Rosenthal fibers are a prerequisite for this diagnosis.** C. It may mimic oligodendroglioma. D. It is a CNS neoplasm seen with neurofibromatosis type 1. E. Recurrence is usually a reformation of the cyst rather than the solid tumor ## Footnote Rosenthal fibers are by no means a requisite feature of pilocytic astrocytoma. Rosenthal fibers are composed of alpha B cystallin and are surrounded by in- termediate filaments.

Answer 15

**E. All of the above** ## Footnote Barbiturates are also thought to stabilize lysosomes, suppress the formation of edema, and reduce intracellular accumulation of calcium. The inverse steal phenomenon involves barbiturate-induced vasoconstriction resulting in shunting of blood from normal brain to relatively ischemic areas.

Answer 16

A. II and III. B. III and IV. **C. IV and V1.** D. V1 and V2. E. V2 and V3 ## Footnote Parkinson’s triangle is also known as the infratrochlear triangle.

Answer 17

A. The majority of acetylcholine receptor antibodies are of the M subtype. B. Cyclosporine is used as a fi rst-line treatment. **C. Corticosteroids may reduce the risk of secondary generalization in the ocular form** D. Pathological abnormalities of the thymus are found in less than 5% of patients. E. Weakness confined to the ocular muscles beyond 3 years is associated with poor prognosis. ## Footnote The majority of acetylcholine receptor (AchR) antibodies are immunoglobulin G (IgG). Cyclosporine should be used once first-line treatments have failed. Pathological abnormalities of the thymus occur in up to 80% of patients. Weak- ness confined to the ocular muscles for over 3 years suggests good prognosis.

Answer 18

**D. sphenoid, temporal, and occipital bones**

Answer 19

A. Neuropathy from diphtheria B. Creutzfeldt–Jakob disease C. Paraneoplastic necrotizing myelopathy D. Central pontine myelinolysis **E. Tolosa–Hunt syndrome** ## Footnote Tolosa–Huntsyndromeischaracterizedbyocularandretro-orbitalpain,ocu- lar motor paralysis (with papillary sparing), and possibly sensory loss over the forehead with granulomatous inflammation of the superior orbital fissure or the lateral wall of the cavernous sinus. The other conditions described lack an inflammatory response.

Answer 20

B. The most accurate description of Wernicke’s area is that it includes the supramarginal (39), angular (40), and posterior one-third of the superior temporal gyri. ## Footnote Tolosa–Hunt syndrome is characterized by ocular and retro-orbital pain, ocular motor paralysis (with papillary sparing), and possibly sensory loss over the forehead with granulomatous inflammation of the superior orbital fissure or the lateral wall of the cavernous sinus. The other conditions described lack an inflammatory response.

Answer 21

A. opsoclonus. Bursts of back-to-back saccades seen in opsoclonus and ocular fl utter may be attributable to a disorder of pause cell modulation of burst cell function. ## Footnote Bursts of back-to-back saccades seen in opsoclonus and ocular flutter may be attributable to a disorder of pause cell modulation of burst cell function.

Answer 22

C. nucleus ambiguus

Answer 23

A. Scan 1 Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction. ## Footnote Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Answer 24

B. Scan 2 Scan 2 shows a meningioma of the cerebellopontine angle (CPA), which usually presents initially with facial nerve involvement. Acoustic schwannomas present initially with hearing loss and tinnitus ## Footnote Scan 2 shows a meningioma of the cerebellopontine angle (CPA), which usually presents initially with facial nerve involvement. Acoustic schwannomas present initially with hearing loss and tinnitus.

Answer 25

**A. Scan 1** B. Scan 2 C. Both scans 1 and 2 D. Neither scan 1 nor scan 2 ## Footnote Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Answer 26

**A. Scan 1** B. Scan 2 C. Both scans 1 and 2 D. Neither scan 1 nor scan 2 ## Footnote Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Answer 27

D. Neither scan 1 nor scan 2

Answer 28

**A. Increased fibrinogen level** B. Prolonged PT C. Prolonged PTT D. Thrombocytopenia E. Fragmented RBCs ## Footnote Disseminated intravascular coagulation (DIC) is most frequently associated with obstetric catastrophes, metastatic malignancy, massive trauma, and bac- terial sepsis. The neurosurgeon should be aware that DIC can occur when there is major cerebral tissue injury. The decrease in fibrinogen most closely corre- lates with increased bleeding. Treatment is by removing the causative agent, heparin, cryoprecipitate, platelets, and whole blood.

Answer 29

C. V3 ## Footnote The mastoid air cells and the posterior middle fossa are innervated by V3. The supratentorial compartment is innervated by V1 and V2. The infratentorial compartment is innervated by IX, X, and C1–C3 posterior roots.

Answer 30

A. It divides the third layer of the cortex of areas 17 and 18. B. It divides the third layer of the cortex of area 17. C. It divides the fourth layer of the cortex of areas 17 and 18. **D. It divides the fourth layer of the cortex of area 17.** E. It divides the fourth layer of the cortex of areas 17, 18, and 19. ## Footnote The band of Gennari divides the fourth layer of cortex into two granular layers with a thick myelin layer. The band is located only in area 17 (primary visual cortex, also known as V1). When Gennari described this in 1782, he had no idea that this or any other region of the visual cortex might be concerned with vision.

Answer 31

**E. Nucleus prepositus hypoglossi** ## Footnote The neural integrator for horizontal eye movement sislocated in the nucleus prepositus hypoglossi (NPH) at the pontomedullary junction.

Answer 32

**C. Climbing fibers** ## Footnote Climbing fiber input is most active at times when the subject is performing new complex movements. The climbing fiber input can modify the synapse between the parallel fiber (from the granule cell) and the Purkinje cell.

Answer 33

A. Cushing’s disease B. Graves’s disease C. Adrenal tumors D. Addison’s disease **E. None of the above** ## Footnote The combination of high trophic hormone and low target hormone indicates target gland failure.

Answer 34

A. Adductor pollicis B. Abductor pollicis brevis C. Flexor pollicis brevis D. Opponens pollicis E**. Extensor pollicis brevis** ## Footnote The opponens pollicis inserts on the first metacarpal bone.

Answer 35

C. The seventh cranial nerve is frequently involved preoperatively ## Footnote The MRI with contrast demonstrates a left cerebellopontine angle lesion most consistent with a vestibular schwannoma. Most patients have involvement of the eighth cranial nerve initially. They may also more commonly present with decreased facial sensation or numbness with involvement of the trigeminal nerve; however, facial nerve involvement with a tumor of the size shown is relatively uncommon.

Answer 36

C. Vergence The medial longitudinal fasciculus (MLF) is responsible for the binocular coordination of all categories of horizontal, vertical, and oblique eye movements with the exception of vergence movements. Upbeating nystagmus on upgaze is a feature of MLF lesions. ## Footnote The medial longitudinal fasciculus (MLF) is responsible for the binocular co- ordination of all categories of horizontal, vertical, and oblique eye movements with the exception of vergence movements. Upbeating nystagmus on upgaze is a feature of MLF lesions.

Answer 37

C. Severity of mental retardation ## Footnote Both Apert’s and Crouzon’s syndromes are autosomal dominant (both may also be sporadic). Both are associated with bilateral coronal synostosis. Patients with Apert’s syndrome manifest more severe mental retardation than patients with Crouzon’s syndrome.

Answer 38

A. prolactin. B. ACTH. C. GH. D. TSH. **E. All of the above** ## Footnote In addition to stimulating the synthesis and secretion of thyroid stimulating hormone (TSH), thyrotropin-releasing hormone (TRH) is a potent secretagogue for prolactin, and to a lesser extent adrenocorticotropic hormone (ACTH), and growth hormone (GH).

Answer 39

A. Radial only B. Radial and median **C. Radial, median, and ulnar** D. Radial, median, and axillary E. Musculocutaneous, median, and ulnar ## Footnote The metacarpophalangeal joint of the ring finger is flexed by the lumbrical, pal- mar, and dorsal interosseous muscles, which are innervated by the ulnar nerve. The joint is extended by the extensor digitorum, which is innervated by the ra- dial nerve. The median nerve is mainly involved with flexion of the ring finger.

Answer 40

A. Survivin B. MMP-9 C. EGFR D. MDM2 **E. Fas (APO-1/CD95)** ## Footnote Profileexpression: Survivin—83% MMP-9—69% EGFR—63% MDM2—31% Fas (APO-1/CD95)—100%

Answer 41

A. Lateral triangle B. Paramedial triangle C. Glasscock’s triangle **D. Kawase’s triangle** E. Parkinson’s triangle

Answer 42

E. Levels are increased after nonepileptic seizures. Serum concentration of prolactin (PRL) is increased after tonicoclonic seizure activity but is not aff ected by nonepileptic seizures. ## Footnote Serum concentration of prolactin (PRL) is increased after tonico clonic seizure activity but is not affected by nonepileptic seizures.

Answer 43

A. Organum vasculosum of the lamina terminalis B. Median eminence of the tuber cinereum C. Subcommissural organ **D. Subfornical organ** E. Area postrema ## Footnote The subfornical organ is located on the inferior surface of the fornix at the level of the foramen of Monro.

Answer 44

**A. It is a branch from the posterior division of the spinal nerve proximal to the dorsal root ganglion.** B. It may enter the intervertebral foramen. C. It supplies most of the innervation to the posterior aspect of the disk. D. It may have a proprioceptive and/or nociceptive function. E. It has been shown to consist of two roots at cervical levels ## Footnote The sinuvertebral nerve arises just distal to the dorsal root ganglion. The pos- terior disk receives its innervation from the sinuvertebral nerves. The anterior disk receives its innervation from the gray rami communicans.

Answer 45

A. It is caused by a lesion of the arcuate fasciculus. **B. There is fluent paraphasic speech with intact repetition.** C. It may be caused by occlusion of a middle cerebral artery(MCA) posterior temporal branch. D. Patients may mimic Wernicke’s disease, but are able to understand. E. Patients are aware of the problem ## Footnote Repetition is impaired in conduction aphasia.

Answer 46

A. It arises from the cavernous internal carotid artery. **B. It measures ~6–8 mm.** C. It usually presents pituitary dysfunction. D. All of the above statements are true. E. None of the above statements are true ## Footnote The usual diameter of the internal cerebral artery at the clinoid area is about 8 mm. This aneurysm is slightly smaller than the artery’s diameter.

Answer 47

A. Vertebral blood flow B. Carotid blood flow C. Cervical stenosis D. Thoracic stenosis E. Lumbar stenosis ## Footnote TheTorg Pavlov ratio is a measure of cervical spinal stenosis and is the ratio of spinal canal to vertebral body. A normal cervical spinal canal will have a ratio of about 1.0. A stenotic cervical canal has a ratio of <0.8

Answer 48

A. Primary glioblastoma has an incidence that is about 10 times higher than secondary glioblastoma. **B. The mean age at presentation in primary glioblastoma is much younger (45 years) than in secondary glioblastoma (62 years)** C. Primary glioblastoma is more common in males when compared with secondary glioblastoma. D. The median survival at presentation is longer in secondary glioblastoma as compared with primary glioblastoma. E. Loss of heterozygosity on 10p or 10q is one of the most common genetic mutations in primary glioblastoma. ## Footnote Primary glioblastoma has an incidence that is about 10 times higher than sec- ondary glioblastoma. The mean age at presentation in secondary glioblastoma is much younger (45 years) than in primary glioblastoma (62 years). Primary glioblastoma is more common in males when compared to secondary glioblas- toma. The median survival at presentation is longer in secondary glioblastoma as compared to primary glioblastoma. Loss of heterozygosity on 10p or 10q is one of the most common genetic mutations in primary glioblastoma.

Answer 49

A. dorsal root ganglia only. B. anterior horn only. **C. sympathetic chain ganglia and dorsal root ganglia.** D. lateral horn and sympathetic chain ganglia. E. None of the above ## Footnote The medial brachial cutaneous nerve (from the medial cord) contains sensory fibers that have cell bodies in the dorsal root ganglia. It also contains sym- pathetic postganglionic fibers that have cell bodies in the sympathetic chain ganglia.

Answer 50

A. inhibitory pathway of the hippocampus. **B. excitatory pathway of the hippocampus.** C. inhibitory pathway of the hypothalamus. D. excitatory pathway of the hypothalamus. E. None of the above ## Footnote The perforant path is the main excitatory pathway to the hippocampus. When perforant path fibers are stimulated, histological changes develop in the py- ramidal nerve cells of CA1 and CA3.

Answer 51

A. Parkinson’s triangle B. Kawase’s triangle C. Glasscock’s triangle **D. Inferior medial triangle** E. Paramedial triangle

Answer 52

A. cluster. **B. tension.** C. migraine. D. postconcussive. E. due to temporal arteritis ## Footnote Up to 80% of the population will experience a tension headache in their life- time. Amitriptyline is the most effective medication used to prevent tension headaches.

Answer 53

A. Cerebellomedullary B. Interpeduncular **C. Ambient** D. Chiasmatic E. Pontine ## Footnote The ambient cistern contains the trochlear nerve.

Answer 54

A. Anterior scalene **B. Anterior and medial** C. Medial and posterior D. Anterior and posterior E. Anterior, medial, and posterior ## Footnote The anterior and medial scalene muscles insert onto the first rib, and the sub- clavian artery, subclavian vein, and brachial plexus pass between them.

Answer 55

A. pure word blindness. **B. pure word deafness** C. mutism. D. anomic aphasia. E. global aphasia ## Footnote Pure word blindness is characterized by alexia without agraphia. The patient is unable to read but is able to understand speech, write, and speak. It is caused by a lesion of the left geniculocalcarine tract and the corpus callosum.

Answer 56

A. Improvement in IQ is often seen postoperatively. B. Behavior is improved after surgery. **C. It is not necessary to preserve the septum pellucidum** D. The foramen of Monro is often plugged with a piece of temporalis muscle. E. Patients are usually uncommunicative for about a week after surgery. ## Footnote Preventing seepage of blood into the ventricular system during a hemispherec- tomy is accomplished by obstructing the foramen of Monro and maintaining the integrity of the septum pellucidum.

Answer 57

**A. horizontal fi bers have a limited functional role** B. vertical fi bers have a limited functional role. C. the pia has a limited functional role. D. All of the above E. None of the above ## Footnote Experiments in functional physiology defined a limited role of the horizontal fibers and reinforced the anatomical principles of vertical columnar organiza- tion in the cortex. This functional columnar organization of cortical architec- ture is the key principle in multiple subpial transection.

Answer 58

A. headache. B. vomiting. C. visual fi eld disturbance. **D. sexual precocity** E. seizures. ## Footnote Sexual precocity is often the presenting symptom of hypothalamic hamarto- mas. Hamartomas may also cause gelastic (laughing) seizures.

Answer 59

A. It is found in superfi cial brain regions. B. It shows intracellular accumulation of lipids. C. It corresponds to WHO grade II. **D. It carries a dismal prognosis** E. It presents in patients with a long history of seizures. ## Footnote Pleomorphic xanthoastrocytoma (PXA) is an astrocytic neoplasm with a rela- tively favorable prognosis.

Answer 60

B. excitatory input from CA3. A. excitatory input from CA1. **B. excitatory input from CA3.** C. inhibitory input from CA1. D. inhibitory input from CA3. E. None of the above ## Footnote ExcitatoryinputfromCA3toCA1pyramidalcellsiscarriedbySchaffercollat- erals. These collaterals spare the CA2 region.

Answer 61

A. Gastrocnemius **B. Tibialis anterior** C. Extensor hallucis longus D. Iliopsoas E. None of the above ## Footnote The MRI scan of the lumbar spine demonstrates a far lateral foraminal disk herniation at L4–L5 on the left side. Most likely, the L4 nerve root will be in- volved and the patient will present with weakness of the tibialis anterior and decreased sensation along an L4 distribution in the left lower extremity.

Answer 62

A. Midline laminectomy approach **B. Paramedian partial facetectomy approach** C. Transforaminal lumbar interbody fusion D. Posterior lumbar interbody fusion E. A and C ## Footnote Althoughamidlinelaminotomyorlaminectomymaybeemployedfordecom- pression and removal of the disk it is often more effective to approach the disk via a direct approach that is paramedian with a partial facetectomy in order to remove the foraminal and extraforaminal portions.

Answer 63

A. Pyramids B. Medial lemniscus C. Fibers of cranial nerve XII **D. Gracile and cuneate nuclei** E. Anterior two-thirds of the spinal cord ## Footnote The gracile and cuneate fasciculi are supplied by the posterior spinal arteries. The paired posterior spinal arteries (arising from either the posterior inferior cerebellar artery (PICA) or vertebral artery) supply the posterior one-third of the spinal cord.

Answer 64

C. Adson’s test Adson’s test is used in the examination of thoracic outlet syndrome. In this example the examiner is checking to see if the radial pulse is obliterated. Compression of nerves causes wasting of muscles supplied by the lower trunk of the brachial plexus ## Footnote Adson’s test is used in the examination of thoracic outlet syndrome. In this example the examiner is checking to see if the radial pulse is obliterated. Com- pression of nerves causes wasting of muscles supplied by the lower trunk of the brachial plexus.

Answer 65

E. Genu The corticobulbar tract is located in the genu of the internal capsule ## Footnote The corticobulbar tract is located in the genu of the internal capsule.

Answer 66

D. Medulla ## Footnote The medial forebrain bundle traverses the entire lateral hypothalamic area and interconnects the septal area and nuclei, the hypothalamus, and the midbrain tegmentum. The medulla is connected with the hypothalamus via the dorsal longitudinal fasciculus, which projects to the parasympathetic nuclei of the brainstem.

Answer 67

D. All of the above It is postulated that the closure of the lambdoid sutures, common in Crouzon’s syndrome, results in cerebellar tonsillar herniation. ## Footnote It is postulated that the closure of the lambdoid sutures, common in Crouzon’s syndrome, results in cerebellar tonsillar herniation.

Answer 68

**A. lateral hypothalamus.** B. anterior hypothalamus. C. posterior hypothalamus. D. ventromedial hypothalamus. E. suprachiasmatic hypothalamus ## Footnote The most severe forms of hypothalamic cachexia are seen in lesions of the lat- eral hypothalamus.

Answer 69

A. temporal cortex. B. cingulate cortex. **C. prefrontal cortex.** D. posterior parietal cortex. E. anterior parietal cortex. ## Footnote Lesions of the prefrontal cortex result in a failure to discriminate odors. The prefrontal cortex receives projections from the pyriform cortex. There is also a projection from the pyriform cortex to the dorsomedial thalamus to the pre- frontal cortex.

Answer 70

**A. Phenylalanine and tyrosine** B. Phenylalanine and tryptophan C. Tyrosine and tryptophan D. Arginine and tyrosine E. Phenylalanine and arginine ## Footnote The amino acids phenylalanine and tyrosine are precursors for catecholamines (dopamine, norepinephrine, epinephrine).

Answer 71

A. Melanoma B. Choriocarcinoma C. Breast carcinoma **D. Renal cell carcinoma** E. Choroid plexus papilloma ## Footnote Renal cell carcinoma has a predilection to the ventricular system.

Answer 72

A. loss of heterozygosity 10q. **B. TP53 mutation.** C. EGFR amplifi cation. D. p16INK4a deletion. E. PTEN mutations (25%). ## Footnote The majority of cases of glioblastomas are primary that develop without clinical or histological evidence of a less malignant precursor lesion. They occur primarily in the elderly and typically present genetically with loss of heterozygosity 10q, EGFR amplification, p16INK4a deletion, and PTEN muta- tions. Secondary glioblastomas occur through progression from low-grade diffuse astrocytoma or anaplastic astrocytoma and tend to present in young- er patients. TP53 mutations are the most frequent in the pathways to these tumors being often present in precursor low-grade astrocytomas.

Answer 73

A. internal cerebral vein and basal vein. **B. inferior sagittal sinus and vein of Galen** C. basal vein and great cerebral vein. D. inferior sagittal vein and basal vein. E. precentral cerebellar vein and internal cerebral vein ## Footnote The straight sinus is formed by the great cerebral vein (of Galen) and the inferior sagittal sinus.

Answer 74

A. ocular fl utter. B. ocular dysmetria. C. ocular bobbing. **D. oscillopsia.** E. opsoclonus ## Footnote Oscillopsia is a condition where objects seem to wiggle; it sometimes accom- panies downbeat nystagmus.

Answer 75

**A. Parasympathetic preganglionic** B. Parasympathetic postganglionic C. Sympathetic postganglionic D. All of the above E. None of the above ## Footnote Atropine blocks only muscarinic receptors, thus only preganglionic synapses are affected.

Answer 76

A. vitamin B1 Wernicke’s encephalopathy is due to defi ciency of thiamine (B1). ## Footnote Wernicke’s encephalopathy is due to deficiency of thiamine (B1).

Answer 77

D. All of the above Gustatory fi bers of the solitary nucleus terminate in the VPM. Fibers carrying thoracic information travel via solitary tract and terminate in the parabrachial nucleus and hypothalamus ## Footnote Gustatory fibers of the solitary nucleus terminate in the VPM. Fibers carrying thoracic information travel via solitary tract and terminate in the parabrachial nucleus and hypothalamus.

Answer 78

B. the presence of mitotic activity. In contrast to diffuse astrocytomas, anaplastic astrocytomas typically display mitotic activity. ## Footnote In contrast to diffuse astrocytomas, anaplastic astrocytomas typically display mitotic activity.

Answer 79

D. cavernous hemangioma The typical site for a cavernous hemangioma of the orbit is in the intraconal space lateral to the optic nerve ## Footnote The typical site for a cavernous hemangioma of the orbit is in the intraconal space lateral to the optic nerve.

Answer 80

D. Exposure to highly active antiretroviral therapy (HAART) HIV-infected individuals have an increased risk of cerebrovascular incidents associated with intravenous drug abuse, low CD4 cell count, and exposure to abacavir, but not with HAART. A CD4 cell count ≤ 200 cells/mL prior the start of HAART increased the risk of cerebrovascular events. ## Footnote HIV-infected individuals have an increased risk of cerebrovascular incidents associated with intravenous drug abuse, low CD4 cell count, and exposure to abacavir, but not with HAART. A CD4 cell count ≤ 200 cells/mL prior the start of HAART increased the risk of cerebrovascular events.

Answer 81

E. periventricula Arteries from the ependymal surface feed the arteriovenous malformation (AVM) ## Footnote Arteries from the ependymal surface feed the arteriovenous malformation (AVM).

Answer 82

A. dopamine beta -hydroxylase. Under conditions of neuronal activation, dopamine beta-hydroxylase is the rate-limiting step. However, under basal conditions tyrosine hydroxylase is the rate-limiting step ## Footnote Under conditions of neuronal activation, dopamine beta-hydroxylase is the rate-limiting step. However, under basal conditions tyrosine hydroxylase is the rate-limiting step.

Answer 83

B. Septal and terminal The venous angle is a landmark of the foramen of Monro. It is formed by the union of the septal vein and the terminal (also called thalamostriate) vein ## Footnote The venous angle is a landmark of the foramen of Monro. It is formed by the union of the septal vein and the terminal (also called thalamostriate) vein.

Answer 84

E. All of the above Ocular bobbing is a rapid downward movement of the eyes with a slow return to midposition and has many causes. ## Footnote Ocular bobbing is a rapid downward movement of the eyes with a slow re- turn to midposition and has many causes.

Answer 85

E. osteoid osteoma This CT scan reveals dense sclerosis around a lytic lesion with a central calcifi ed nodule in the lumbar neural arch consistent with osteoid osteoma. ## Footnote This CT scan reveals dense sclerosis around a lytic lesion with a central calcified nodule in the lumbar neural arch consistent with osteoid osteoma.

Answer 86

C. the arcuate nuclei The striae medullares (rhombencephali) arise from the arcuate nuclei of the medulla and are seen on the floor of the rhomboid fossa. These fibers divide the rhomboid fossa into a rostral pontine half and a caudal medullary half. The stria medullaris (thalami) contains septohabenular fi bers. The stria terminalis is a semicircular fi ber bundle extending from the amygdala to the hypothalamus and septal area ## Footnote The striae medullares (rhombencephali) arise from the arcuate nuclei of the medulla and are seen on the floor of the rhomboid fossa. These fibers divide the rhomboid fossa into a rostral pontine half and a caudal medullary half. The stria medullaris (thalami) contains septohabenular fibers. The stria ter- minalis is a semicircular fiber bundle extending from the amygdala to the hypothalamus and septal area.

Answer 87

C. diffusion. No blood vessels penetrate the intervertebral disk. Delivery of nutrients is entirely dependent on diff usion ## Footnote No blood vessels penetrate the intervertebral disk. Delivery of nutrients is entirely dependent on diffusion.

Answer 88

D. Stimulation of it inhibits acoustic fi ber responses to auditory stimuli. The olivocochlear bundle arises from the region of the superior olivary nucleus and projects contralaterally back to the hair cells of the cochlea. Stimulation of this bundle results in nhibition or reduction of responses of auditory signals by auditory nerve fibers. ## Footnote The olivocochlear bundle arises from the region of the superior olivary nucleus and projects contralaterally back to the hair cells of the cochlea. Stimulation of this bundle results in inhibition or reduction of responses of auditory signals by auditory nerve fibers.

Answer 89

B. Pleomorphic adenoma of the lacrimal gland Pleomorphic adenomas of the lacrimal gland should be removed with a cuff of normal tissue to reduce the risk of tumor seeding and recurrence. An incisional biopsy should not be performed on this type of tumor. ## Footnote Pleomorphic adenomas of the lacrimal gland should be removed with a cuff of normal tissue to reduce the risk of tumor seeding and recurrence. An inci- sional biopsy should not be performed on this type of tumor.

Answer 90

C. Palatine and sphenoid

Answer 91

C. Broca’s area.

Answer 92

C. The fluid collection is typically not lined by ependymal cells. Hydromyelia has ependymal lining. It can be associated with both hydrocephalus and Chiari but can also be postmeningitic and associated with tumors. It can be either communicating with the fourth ventricle or just isolated and noncommunicating. Syrinxes on the other hand lack any ependymal lining. ## Footnote Hydromyelia has ependymal lining. It can be associated with both hydro- cephalus and Chiari but can also be postmeningitic and associated with tumors. It can be either communicating with the fourth ventricle or just iso- lated and noncommunicating. Syrinxes on the other hand lack any ependy- mal lining.

Answer 93

B. Superior cerebellar artery The superior cerebellar artery supplies the superior surface of the cerebellum and the cerebellar nuclei ## Footnote The superior cerebellar artery supplies the superior surface of the cerebel- lum and the cerebellar nuclei.

Answer 94

D. at the vestibular nuclei In the comatose patient, a lesion at the level of the vestibular nuclei results in extensor movements of the arms and weak flexor movements of the legs. Flaccidity of the lower and upper extremities occurs with lesions below the vestibular nuclei. Lesions above the red nucleus (decorticate) result in flexion of the upper and extension of the lower extremities. Lesions below the red nucleus (and above the vestibular nuclei) result in extensor posturing of all extremities (decerebrate). ## Footnote In the comatose patient, a lesion at the level of the vestibular nuclei results in extensor movements of the arms and weak flexor movements of the legs. Flaccidity of the lower and upper extremities occurs with lesions below the vestibular nuclei. Lesions above the red nucleus (decorticate) result in flexion of the upper and extension of the lower extremities. Lesions below the red nucleus (and above the vestibular nuclei) result in extensor posturing of all extremities (decerebrate).

Answer 95

E. cranial nerve VII reaching the sphenopalatine ganglion Fibers of the chorda tympani reach the sphenopalatine ganglion to produce “crocodile tears,” also known as Bogorad’s syndrome ## Footnote Fibers of the chorda tympani reach the sphenopalatine ganglion to produce “crocodile tears,” also known as Bogorad’s syndrome.

Answer 96

A. N13 With a cervical syrinx, one would expect attenuation or abolition of the cervical N13 evoked potential. N13 attenuation may be due to involvement of those laminae of the dorsal horn that receive input from large-diameter mechano-receptor fi bers ## Footnote With a cervical syrinx, one would expect attenuation or abolition of the cervical N13 evoked potential. N13 attenuation may be due to involvement of those laminae of the dorsal horn that receive input from large-diameter mechano-receptor fibers.

Answer 97

C. Wolff ’s law Wolff ’s law states that a bone develops the structure most suited to resist the forces acting upon it. Sherrington’s law: every posterior spinal nerve supplies a special region of skin. Jackson’s law: the nerve functions that are latest developed are the fi rst to be lost. Delpech’s principle: in spondylolisthesis, when slippage reaches around 30% the anterior inferior part grows at a faster rate than the overloaded posterior part of the vertebral body. Flourens’ law deals with nystagmus, not spine biomechanics ## Footnote Wolff’s law states that a bone develops the structure most suited to resist the forces acting upon it. Sherrington’s law: every posterior spinal nerve sup- plies a special region of skin. Jackson’s law: the nerve functions that are latest developed are the first to be lost. Delpech’s principle: in spondylolisthesis, when slippage reaches around 30% the anterior inferior part grows at a faster rate than the overloaded posterior part of the vertebral body. Flourens’ law deals with nystagmus, not spine biomechanics.

Answer 98

D. display all of the above features Chordomas tend to be in the midline, whereas chondrosarcomas are more frequently found off the midline (at the petrosphenoid synchondrosis). Chordomas express S-100 only variably. Normal neurological examinations are more common in patients with chordoma, whereas visual loss, facial numbness, and multiple cranial neuropathies are more common in patients with chondrosarcoma. These differences probably reflect the tendency of chordomas to originate from the clivus and chondrosarcomas from the temporal bone. ## Footnote Chordomas tend to be in the midline, whereas chondrosarcomas are more fre- quently found off the midline (at the petrosphenoid synchondrosis). Chordo- mas express S-100 only variably. Normal neurological examinations are more common in patients with chordoma, whereas visual loss, facial numbness, and multiple cranial neuropathies are more common in patients with chondrosar- coma. These differences probably reflect the tendency of chordomas to origi- nate from the clivus and chondrosarcomas from the temporal bone.

Answer 99

A. Medically refractory essential tremor Thalamotomy is quite eff ective for medically refractory essential tremor. The Parkinson’s patients who benefi t most from thalamotomy are usually young, with tremor-predominant Parkinson’s disease. ## Footnote Thalamotomy is quite effective for medically refractory essential tremor. The Parkinson’s patients who benefit most from thalamotomy are usually young, with tremor-predominant Parkinson’s disease.

Answer 100

D. The midway point between the exit of the dorsal and ventral rootlets Due to considerable variation in the attachment of the dentate ligament, the best estimate of the equator is the midway point of the dorsal and ventral ootlets. The equator is a useful landmark for the posterior extent of a cordotomy incision and marks the point of the sacralmost fi bers of the spinothalamic tract. The exiting ventral root is about 5 mm from the anterior spinal artery. ## Footnote Due to considerable variation in the attachment of the dentate ligament, the best estimate of the equator is the midway point of the dorsal and ventral rootlets. The equator is a useful landmark for the posterior extent of a cor- dotomy incision and marks the point of the sacralmost fibers of the spinotha- lamic tract. The exiting ventral root is about 5 mm from the anterior spinal artery.

Answer 101

C. 14 months It usually takes 12 to 18 months for radiation changes to appear on MRI scans. ## Footnote It usually takes 12 to 18 months for radiation changes to appear on MRI scans.

Answer 102

C. the activity of aromatic amino acid decarboxylase is high L-dopa is converted very quickly to dopamine by aromatic L-amino acid decarboxylase (AADC). Dopamine is converted to norepinephrine (NE) by dopamine beta hydroxylase, which is found in vesicles within the catecholaminergic neuron. ## Footnote L-dopa is converted very quickly to dopamine by aromatic L-amino acid decarboxylase (AADC). Dopamine is converted to norepinephrine (NE) by dopamine beta hydroxylase, which is found in vesicles within the catecholaminergic neuron.

Answer 103

A. The length constant is directly proportional to the membrane resistance The length constant is the distance along a fi ber where a change in the membrane potential produced by a given current decays to a value of approximately one-third of its original value. It is directly proportional to membrane resistance and inversely related to axial resistance (the resistance of the cytoplasm within the fi ber). ## Footnote The length constant is the distance along a fiber where a change in the mem- brane potential produced by a given current decays to a value of approxi- mately one-third of its original value. It is directly proportional to membrane resistance and inversely related to axial resistance (the resistance of the cy- toplasm within the fiber).

Answer 104

D. Mast cell Raynaud’s phenomenon is caused by mast cell dysfunction; sympathectomy has not proven helpful. Half of these patients have collagen vascular disease. ## Footnote Raynaud’s phenomenon is caused by mast cell dysfunction; sympathectomy has not proven helpful. Half of these patients have collagen vascular disease.

Answer 105

D. All of the above Epidural hematomas are the most common intracranial hematoma in children. Although an arterial component is of major concern, diff use oozing from the bone or from the highly vascularized periosteal surface of the dura is now considered to be a more common source of epidural hematomas in children. ## Footnote Epidural hematomas are the most common intracranial hematoma in chil- dren. Although an arterial component is of major concern, diffuse oozing from the bone or from the highly vascularized periosteal surface of the dura is now considered to be a more common source of epidural hematomas in children.

Answer 106

**E. L5** Spondylolysis is a bone defect in the posterior vertebral arch between the upper and lower articular processes, that is, the isthmus or pars interarticularis. ## Footnote Spondylolysis is a bone defect in the posterior vertebral arch between the upper and lower articular processes, that is, the isthmus or pars interarticularis.

Answer 107

B. a nerve arising from the roots of the brachial plexus. Winged scapula is caused by paralysis of the serratus anterior muscle as a result of damage to the long thoracic nerve that arises from the roots of the brachial plexus (C5–C7) ## Footnote Winged scapula is caused by paralysis of the serratus anterior muscle as a result of damage to the long thoracic nerve that arises from the roots of the brachial plexus (C5–C7).

Answer 108

A. Vim The typical thalamotomy target is the Vim (ventralis intermedius) nucleus. Often just inserting the electrode into Vim reduces the tremor (microthalamotomy eff ect), and indicates that the electrode is in a good position ## Footnote The typical thalamotomy target is the Vim (ventralis intermedius) nucleus. Often just inserting the electrode into Vim reduces the tremor (microth- alamotomy effect), and indicates that the electrode is in a good position.

Answer 109

D. All of the above All are derived from the telencephalon. ## Footnote All are derived from the telencephalon.

Answer 110

D. on the medial surface of the parietal lobe

Answer 111

E. Sensory defi cit along the rib cage The MRI represents thoracic diskitis at a midthoracic level. Oftentimes this can be treated medically. Indications for surgery, however, do include failure of medical treatments, requirement for identifi cation of off ending agent via biopsy, mass eff ect caused by ompression of the cord, or instability that is caused by an abscess or signifi cant bony estruction. Sensory defi cit alone is not a clear indication for surgical intervention. ## Footnote The MRI represents thoracic diskitis at a midthoracic level. Oftentimes this can be treated medically. Indications for surgery, however, do include failure of medical treatments, requirement for identification of offending agent via biopsy, mass effect caused by compression of the cord, or instability that is caused by an abscess or significant bony destruction. Sensory deficit alone is not a clear indication for surgical intervention.

Answer 112

B. Bipolar cells

Answer 113

D. Spiral ganglion The spiral ganglion consists of bipolar neurons of the cochlear division of the vestibulocochlear nerve. ## Footnote The spiral ganglion consists of bipolar neurons of the cochlear division of the vestibulocochlear nerve.

Answer 114

E. Supplementary motor area The supplementary motor area (area 6) is unique because a lesion in that location is associated with no language output, usually with complete recovery in weeks to months. This is in contrast with the perisylvian language sites. ## Footnote The supplementary motor area (area 6) is unique because a lesion in that lo- cation is associated with no language output, usually with complete recovery in weeks to months. This is in contrast with the perisylvian language sites.

Answer 115

A. the sphenoid bone anterior to the greater and lesser superfi cial petrosal nerves. During middle fossa approaches, this anatomy can be appreciated. As the dura is elevated, branches of the middle meningeal artery are encountered, and the greater and lesser superfi cial petrosal nerves are identifi ed immediately posterior to the foramen spinosum. With careful bone removal, the greater superfi cial petrosal nerve can be traced back to the geniculate ganglion. ## Footnote During middle fossa approaches, this anatomy can be appreciated. As the dura is elevated, branches of the middle meningeal artery are encountered, and the greater and lesser superficial petrosal nerves are identified immediately posterior to the foramen spinosum. With careful bone removal, the greater superficial petrosal nerve can be traced back to the geniculate ganglion.

Answer 116

E. V The position of the posterior inferior tip of L5 above one of the quarters characterizes grade I, II, III, or IV spondylolisthesis, respectively (III–V being higher grades). ## Footnote The position of the posterior inferior tip of L5 above one of the quarters char- acterizes grade I, II, III, or IV spondylolisthesis, respectively (III–V being high- er grades).

Answer 117

D. All of the above Golgi tendon organs detect tension in the muscle fi ber. Aff erent signals are carried by Ib fi bers to interneurons that decrease the alpha motor neuron output. ## Footnote Golgi tendon organs detect tension in the muscle fiber. Afferent signals are carried by Ib fibers to interneurons that decrease the alpha motor neuron output.

Answer 118

D. All of the above The ventralis intermedius (Vim) is thought to be a relay nucleus for kinesthetic sensation. All observations indicate placement in the Vim. Contralateral paresthesias from stimulation of the Vim occur at higher thresholds than those obtained from the ventralis caudalis (VC) nucleus (posterior to the Vim). ## Footnote The ventralis intermedius (Vim) is thought to be a relay nucleus for kines- thetic sensation. All observations indicate placement in the Vim. Contralat- eral paresthesias from stimulation of the Vim occur at higher thresholds than those obtained from the ventralis caudalis (VC) nucleus (posterior to the Vim).

Answer 119

C. tufted and mitral cells Glomeruli of the olfactory nerve are composed of mitral and tufted cells. Axons of mitral and tufted cells go on to form the lateral olfactory tract. ## Footnote Glomeruli of the olfactory nerve are composed of mitral and tufted cells. Ax- ons of mitral and tufted cells go on to form the lateral olfactory tract.

Answer 120

A. MCA only The sylvian triangle is defi ned angiographically by (1) the most posterior branch of the middle cerebral artery as it exits the sylvian fi ssure, (2) branches of superior ramifi cations of the MCA, and (3) inferior loops of the MCA. ## Footnote The sylvian triangle is defined angiographically by (1) the most posterior branch of the middle cerebral artery as it exits the sylvian fissure, (2) branch- es of superior ramifications of the MCA, and (3) inferior loops of the MCA.

Answer 121

D. MAOA and MAOB are associated with the inner mitochondrial membrane. MAOA and MAOB are associated with the outer mitochondrial membrane. ## Footnote MAOA and MAOB are associated with the outer mitochondrial membrane.

Answer 122

A. Metencephalon The metencephalon is a secondary vesicle that becomes the pons, cerebellum, and upper part of the fourth ventricle. The myelencephalon becomes the medulla and the lower part of the fourth ventricle ## Footnote The metencephalon is a secondary vesicle that becomes the pons, cerebel- lum, and upper part of the fourth ventricle. The myelencephalon becomes the medulla and the lower part of the fourth ventricle.

Answer 123

A. Tectorial membrane The tectorial membrane is a projection of the spiral limbus that overlies hair cells of the organ of Corti. The basilar membrane supports the organ of Corti and separates the cochlear duct from the scala tympani. The vestibular (Reissner’s membrane) separates the scala vestibuli from the cochlear duct ## Footnote The tectorial membrane is a projection of the spiral limbus that overlies hair cells of the organ of Corti. The basilar membrane supports the organ of Corti and separates the cochlear duct from the scala tympani. The vestibular (Re- issner’s membrane) separates the scala vestibuli from the cochlear duct.

Answer 124

B. Solitary projections to the nucleus ambiguus Solitary projections to the nucleus ambiguus are largely bilateral and are the intermediate neurons in the pathway for the gag refl ex. ## Footnote Solitary projections to the nucleus ambiguus are largely bilateral and are the intermediate neurons in the pathway for the gag reflex.

Answer 125

C. Pedicle screw fusion of L4–L5 The film shows a grade I spondylolisthesis at L4–L5. Although management of this problem is wide ranging, from the choices given the best management is a pedicle screw fusion at the concerning levels (L4–L5) ## Footnote The film shows a grade I spondylolisthesis at L4–L5. Although management of this problem is wide ranging, from the choices given the best management is a pedicle screw fusion at the concerning levels (L4–L5).

Answer 126

B. GABA-B The GABA-B receptor is activated by the GABA analogue baclofen, is not chloride dependent, and is bicuculline insensitive. GABA-C is found in the retina, hippocampus, and cerebellum, and is insensitive to baclofen and bicuculline ## Footnote The GABA-B receptor is activated by the GABA analogue baclofen, is not chlo- ride dependent, and is bicuculline insensitive. GABA-C is found in the retina, hippocampus, and cerebellum, and is insensitive to baclofen and bicuculline.

Answer 127

C. Cranial nerve IV Structures that pass above the tendinous ring are the lacrimal nerve, frontal nerve, and CN IV (trochlear) ## Footnote Structures that pass above the tendinous ring are the lacrimal nerve, frontal nerve, and CN IV (trochlear).

Answer 128

C. Staphylococcus The most common causative organism of brain abscesses in trauma is Staphylococcus. ## Footnote The most common causative organism of brain abscesses in trauma is Staphylococcus.

Answer 129

B. Streptococcus The most common causative organism of brain abscesses in adults due to chronic otitis is Streptococcus ## Footnote The most common causative organism of brain abscesses in adults due to chronic otitis is Streptococcus.

Answer 130

A. Proteus The most common causative organisms of brain abscesses in neonates are Citrobacter, Bacteroides, Proteus and gram-negative bacilli ## Footnote The most common causative organisms of brain abscesses in neonates are Citrobacter, Bacteroides, Proteus and gram-negative bacilli.

Answer 131

A. an inhibitor of MAOA. Tranylcypromine is an inhibitor of MAOA. Deprenyl is a specifi c inhibitor of MAO ## Footnote Tranylcypromine is an inhibitor of MAOA. Deprenyl is a specific inhibitor of MAOB.

Answer 132

B. Floor plate The floor plate contains the ventral white commissure ## Footnote The floor plate contains the ventral white commissure.

Answer 133

E. Abnormalities of chromosome 9 are seen Sturge–Weber syndrome occurs sporadically without Mendelian inheritance and is of unknown etiology. ## Footnote Sturge–Weber syndrome occurs sporadically without Mendelian inheritance and is of unknown etiology.

Answer 134

E. All of the above There are nonchoroid plexus sites of cerebrospinal fluid (CSF) production. Likewise there are sites of absorption other than the arachnoid granulations (paranasal sinuses, cervical lymphatics, exiting nerve roots, and transependymal flow) ## Footnote There are nonchoroid plexus sites of cerebrospinal fluid (CSF) production. Likewise there are sites of absorption other than the arachnoid granulations (paranasal sinuses, cervical lymphatics, exiting nerve roots, and transepend- ymal flow).

Answer 135

C. 15% In patients with known systemic cancer, 10–15% of single brain lesions are cerebral abscesses or primary brain tumors. ## Footnote In patients with known systemic cancer, 10–15% of single brain lesions are cerebral abscesses or primary brain tumors.

Answer 136

A. GABA breakdown. Vigabatrin interferes with GABA breakdown, whereas tiagabine interferes with GABA reuptake ## Footnote Vigabatrin interferes with GABA breakdown, whereas tiagabine interferes with GABA reuptake.

Answer 137

B. the hippocampus.

Answer 138

B. lateral. Lesions placed too laterally during thalamotomy risk injury to the internal capsule (posterior limb). Lesions placed too posterior may cause contralateral hemisensory defi cits owing to injury of the ventralis caudalis (VC) nucleus. ## Footnote Lesions placed too laterally during thalamotomy risk injury to the internal capsule (posterior limb). Lesions placed too posterior may cause contralater- al hemisensory deficits owing to injury of the ventralis caudalis (VC) nucleus.

Answer 139

B. Cyclosporine Cyclosporine along with some of the newer immunosuppressive agents (FK-506 or tacrolimus) work at the level of the T cells by inhibiting expression of IL-2. ## Footnote Cyclosporine along with some of the newer immunosuppressive agents (FK-506 or tacrolimus) work at the level of the T cells by inhibiting expression of IL-2.

Answer 140

E. P1 The perforating arteries from the Pcom are termed the anterior thalamo-perforating arteries. Those from the P1 are called the posterior thalamo-perforating arteries. Those from P2 are termed the thalamo-geniculate arteries. ## Footnote The perforating arteries from the Pcom are termed the anterior thalamo-perforating arteries. Those from the P1 are called the posterior thalamo-perforating arteries. Those from P2 are termed the thalamo-genicu- late arteries.

Answer 141

D. Arcuate

Answer 142

E. Nucleus ambiguus The basal plate gives rise to the hypoglossal nucleus, nucleus ambiguus, dorsal motor nucleus of the vagal nerve, and inferior salivatory nucleus ## Footnote The basal plate gives rise to the hypoglossal nucleus, nucleus ambiguus, dor- sal motor nucleus of the vagal nerve, and inferior salivatory nucleus.

Answer 143

B. 20–45°

Answer 144

B. Kocher’s point. Kocher’s point places the atheter in the frontal horn of the lateral ventricle. One can measure 1 cm anteriorly to the coronal suture or 3.5 cm in front of the bregma. This precaution is to avoid the motor strip. Keen’s point would be used for placement of the catheter in the trigone and would require entrance through the posterior parietal region ## Footnote Kocher’s point places the catheter in the frontal horn of the lateral ventricle. One can measure 1 cm anteriorly to the coronal suture or 3.5 cm in front of the bregma. This precaution is to avoid the motor strip. Keen’s point would be used for placement of the catheter in the trigone and would require en- trance through the posterior parietal region.

Answer 145

B. Ipsilateral Horner’s syndrome ## Footnote The MRI demonstrates absent flow voids in the left vertebral artery, a finding seen in Wallenberg syndrome.

Answer 146

C. Clonazepam ## Footnote Clonazepam acts by increasing GABA-A opening frequency and does not have any hepatic enzyme–inducing properties.

Answer 147

A. the contralateral red nucleus

Answer 148

E. Postural instability Freezing episodes and postural instability do not appear to be improved with pallidotomy ## Footnote Freezing episodes and postural instability do not appear to be improved with pallidotomy.

Answer 149

C. Neurological complications are the presenting feature of AIDS in 20% of cases Neurological involvement in HIV infection is more common in children than in adults. Neurological complications occur in > 40% of patients with HIV infection. They are the presenting feature of AIDS in 10–20% of patients. The prevalence of neuropathological abnormalities upon autopsy is 80%. Although an ongoing decline in HIV-associated CNS disease has been seen in very recent years, the mortality from these diseases remains elevated ## Footnote Neurological involvement in HIV infection is more common in children than in adults. Neurological complications occur in > 40% of patients with HIV infection. They are the presenting feature of AIDS in 10–20% of patients. The prevalence of neuropathological abnormalities upon autopsy is 80%. Al- though an ongoing decline in HIV-associated CNS disease has been seen in very recent years, the mortality from these diseases remains elevated.

Answer 150

C. proximal two-thirds of the basilar artery.

Answer 151

B. The majority of body stores of serotonin are found in the central nervous system. Serotonin is found in many cells that are not neurons, such as platelets, mast cells, and enterochromaffi n cells. In fact, the brain accounts for only about 1% of body stores of serotonin. ## Footnote Serotonin is found in many cells that are not neurons, such as platelets, mast cells, and enterochromaffin cells. In fact, the brain accounts for only about 1% of body stores of serotonin.

Answer 152

E. Superior colliculus The alar plate gives rise to the layers of the superior colliculus and to the nuclei of the inferior colliculus. ## Footnote The alar plate gives rise to the layers of the superior colliculus and to the nuclei of the inferior colliculus.

Answer 153

A. Tumor necrosis factor-alpha and interleukin (IL)-8 Studies comparing nucleus pulposus material from disk herniation versus painful degenerative disk disease have shown that protein expression of tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 is increased in the degenerative disk disease group, and both groups had similar levels of IL-1β, IL-6, and IL-12. Therefore, TNF-α and IL-8 may be promising candidates to treat patients with diskogenic back pain on a molecular level. ## Footnote Studies comparing nucleus pulposus material from disk herniation versus painful degenerative disk disease have shown that protein expression of tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 is increased in the degenerative disk disease group, and both groups had similar levels of IL-1β, IL-6, and IL-12. Therefore, TNF-α and IL-8 may be promising candidates to treat patients with diskogenic back pain on a molecular level.

Answer 154

D. Transversalis fascia When dissecting below the arcuate line, the transversalis fascia is the only fascial layer between the rectus abdominis and the peritoneum ## Footnote When dissecting below the arcuate line, the transversalis fascia is the only fascial layer between the rectus abdominis and the peritoneum.

Answer 155

B. Ependymoma Cranial neuropathies are a more common presenting sign of ependymomas than other tumors due to their tendency to arise from the fl oor of the fourth ventricle. Medulloblastomas typically arise from the inferior medullary velum. ## Footnote Cranial neuropathies are a more common presenting sign of ependymo- mas than other tumors due to their tendency to arise from the floor of the fourth ventricle. Medulloblastomas typically arise from the inferior medul- lary velum.

Answer 156

D. All of the above Lissauer’s tract caps the dorsal horns, and these fi bers terminate in the substantia gelatinosa (lamina II ## Footnote Lissauer’s tract caps the dorsal horns, and these fibers terminate in the sub- stantia gelatinosa (lamina II).

Answer 157

B. at the junction of the insula and the frontal lobe. The limen insula is part of the primary olfactory cortex and is found at the junction of the insular and frontal lobe cortex. ## Footnote The limen insula is part of the primary olfactory cortex and is found at the junction of the insular and frontal lobe cortex.

Answer 158

C. optic tract. If the electrode is correctly placed, visual thresholds are usually between 2 and 3 V. Higher values indicate that the electrode is too far superior. Lower values indicate that the electrode is too far inferior. ## Footnote If the electrode is correctly placed, visual thresholds are usually between 2 and 3 V. Higher values indicate that the electrode is too far superior. Lower values indicate that the electrode is too far inferior.

Answer 159

B. lateral mesencephalic vein.

Answer 160

B. Glutamate

Answer 161

A. It is transmitted in an autosomal recessive pattern. In stiff person syndrome, the stiff ness primarily aff ects the truncal muscles and is superimposed by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms. The pattern of inheritance is unknown. Patients generally have high amounts of glutamic acid decarboxylase antibody titers. ## Footnote In stiff person syndrome, the stiffness primarily affects the truncal muscles and is superimposed by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms. The pattern of inheritance is unknown. Patients generally have high amounts of glutamic acid decarboxylase antibody titers.

Answer 162

B. IL-3 Inflammatory mediators including interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α are expressed at higher levels in “diseased” intervertebral dis ## Footnote Inflammatory mediators including interleukin (IL)-1β, IL-6, IL-8, and tumor ne- crosis factor-α are expressed at higher levels in “diseased” intervertebral disks.

Answer 163

E. All of the above

Answer 164

A. Low levels of prolactin

Answer 165

D. Elevated adrenocorticotrophic hormone Enlarged pituitary stalk may be due to sarcoidosis, which can present with elevated angiotensin-converting enzyme levels. It may also be due to Langerhans cell histiocytosis, which may present with eosinophilic granuloma. It can occur in cases of meningitis in children. It is very rarely associated with primary pituitary tumors. ## Footnote Enlarged pituitary stalk may be due to sarcoidosis, which can present with elevated angiotensin-converting enzyme levels. It may also be due to Langer- hans cell histiocytosis, which may present with eosinophilic granuloma. It can occur in cases of meningitis in children. It is very rarely associated with primary pituitary tumors.

Answer 166

D. only the contralateral lower face ## Footnote Central facial palsy is usually characterized by either hemiparalysis or hemi- paresis of the contra-lateral muscles in facial expression. Muscles on the forehead are typically intact. Patients have lost voluntary control of muscle movement in the face; however, muscles in the face involved in spontaneous emotional expression usually remain intact.

Answer 167

C. the middle cerebellar peduncle.

Answer 168

**A. completeness of primary tumor excision and extent of involvement at presentation.** B. TP53 overexpression. C. the presence of Homer–Wright rosettes on pathology. D. neuron-specifi c enolase expression. E. destruction of the cribriform plate. ## Footnote Esthesioneuroblastoma has a variable outcome that is primarily prognosti- cated by the extent of involvement at presentation (Kadish stage and lymph nodes metastasis) and completeness of resection.

Answer 169

A. increased latency in wave 3. B. decreased latency in wave 4. C. decreased latency in wave 5. D. increased latency in wave 4. **E. increased latency in wave 5.** ## Footnote Brainstem auditory evoked potentials (BSAEP) measure the timing of electrical waves from the brainstem in response to clicks or tone bursts in the ear. Com- puter averaging over time filters background noise to generate an averaged re- sponse of the auditory pathway to an auditory stimulus. Three waves (I, III and V) are plotted for each ear. The waveform represents specific anatomical points along the auditory neural pathway: the cochlear nerve and nuclei (waves I and II), superior olivary nucleus (wave III), lateral lemniscus (wave IV), and inferior colliculi (wave V). The most reliable indicator of retraction during vestibular schwannoma surgery from the BSAEP is the interaural latency differences in wave V; the latency in the abnormal ear is prolonged.

Answer 170

**B. pyramidal cells of the cerebral cortex** C. pyramidal cells of the hippocampus. D. septal region. E. lateral entorhinal cortex

Answer 171

A. They receive group Ia primary aff erent fibers. B. They receive group II secondary aff erent fibers. C. They are associated with fl ower spray endings. D. They are associated with static gamma efferent fibers. **E. They respond to muscle tension** ## Footnote Golgi tendon organs are sensitive to muscle tension.

Answer 172

A. cysticercosis. B. histoplasmosis. **C. Lyme disease.** D. mucormycosis E. hydatid disease. ## Footnote Lyme disease is an inflammatory disease caused by the spirochetes Borrelia burgdorferi, which are transmitted by the bite of infected Ixodes ticks. Lyme disease is endemic in Massachusetts, Connecticut, Maine, New Hampshire, Rho- de Island, New York, New Jersey, Pennsylvania, Delaware, Maryland, Michigan, and Wisconsin. It is categorized into early localized, early disseminated, and late. There may be an erythema migrans or systemic complaints in the early localized phase. Early disseminated Lyme disease can present with many central nervous system manifestations, including meningitis, altered mental status, radiculop- athy and cranial neuropathy. If left untreated, sequelae include rheumatologic symptoms (monoarticular or oligoarticular arthritis) in 60%, neurologic signs and symptoms in 10%, and cardiac complications in 5% of cases.

Answer 173

**A. It is a well-described complication of VP shunts.** B. It is due to deposition of immune complexes in the glomeruli of kidneys. C. The diagnosis is suspected with hematuria, elevated erythrocyte sedimentation rate (ESR), and decreased complement levels. D. Proper treatment entails removing the entire shunt. E. There is an elevated peripheral WBC count ## Footnote Shunt nephritis is a well-described complication of ventriculoatrial (VA) shunts. VA shunt complications are much more severe and potentially life-threatening than ventriculoperitoneal (VP) shunt complications.

Answer 174

A. Male predominance has been noted. B. It is a surgically curable cause of partial seizures. **C. There is an abundance of mitoses with no necrosis.** D. It is a mixed glial and neuronal neoplasm. E. It shows on CT scans as a hypodense pseudocystic lesion ## Footnote There is a paucity of mitoses and no necrosis in dysembryoplastic neuroepi- thelial tumors (DNET).

Answer 175

A. Transsphenoidal resection B. Bromocriptine C. Angiography **D. Ophthalmologic evaluation** E. Transcranial resection ## Footnote The patient likely presents with an adrenocorticotropic hormone (ACTH)-secreting macroadenoma. Proper evaluation prior to surgery includes ophthalmologic and endocrine consultations and an endocrine panel of laboratory tests.

Answer 176

D. Inferior, inferior

Answer 177

A. Olivocerebellar B. Reticulocerebellar C. Dorsal spinocerebellar **D. All of the above** E. None of the above ## Footnote All of the information that is passed between the brainstem and the cerebel- lum enters and exits through one of three cerebellar peduncles: (1) inferior cerebellar peduncle or restiform body at the level of the medulla, (2) middle cerebellar peduncle or brachium pontis at the level of the pons, (3) superior cerebellar peduncle or brachium conjunctivum at the level of the midbrain. The vestibulocerebellar tract traverses the juxtarestiform body.

Answer 178

A. n-Myc amplifi cation. B. 1p deletion. **C. TrkA expression.** D. older age. E. None of the abo ## Footnote Higher levels of TrkA are seen in neuroblastomas with favorable histology. The other factors listed are associated with a worse prognosis in neuroblastomas.

Answer 179

A. mastoid tip. B. key hole. **C. asterion** D. bregma. E. lambda

Answer 180

A. acetyl CoA. B. acetylcholinesterase. **C. choline acetyltransferase.** D. choline. E. sensitivity to hemicholinium-3. ## Footnote Choline acetyltransferase is the definitive marker for cholinergic neurons. Hemicholimium-3 blocks the high-affinity cholinergic reuptake process.

Answer 181

Tanycytes are most likely to be found in ## Footnote Tanycytes are a variety of ependymal cells found in the wall of the third ven- tricle. The tanycyte is a cell with intermediate features between astrocytes and ependymal cells.

Answer 182

C.C ## Footnote The diagram shown represents the lumbar plexus, structure A is the ilioin- guinal nerve, B is the genitofemoral nerve, C is the lateral femoral cutaneous nerve, D is the femoral nerve, and E is the obturator nerve.

Answer 183

A. between the pyramid and the olive. **B. between the olive and the inferior cerebellar peduncle.** C. from the same sulcus as CN XII. D. from the dorsomedial sulcus. E. from none of the above.

Answer 184

B. prosoprognosia Facial agnosia (prosoprognosia) results from bilateral damage to the medial basal occipitotemporal cortex ## Footnote Facial agnosia (prosoprognosia) results from bilateral damage to the medial basal occipitotemporal cortex.

Answer 185

A. spinal cord compression. B. Ondine’s curse. C. opsoclonus syndrome. D. diarrhea. **E. All of the above** ## Footnote All of the above may be the presentation in children with neuroblastomas. Diarrhea is from vasoactive intestinal polypeptide (VIP) secretion by the tu- mor. Ondine’s curse results from impaired autonomic control of respiration.

Answer 186

A. the results of the Goldman perimetry fi eld. B. being male. **C. the preoperative prolactin level.** D. the age of the patient. E. being female.

Answer 187

A. conversion of R-arginine into nitrous oxide (NO). B. conversion of citrulline into NO. C. production of NO and L-arginine. **D. production of NO and citrulline.** E. None of the above ## Footnote The synthesis of NO (nitrous oxide) involves the conversion of L-arginine into NO and citrulline. All three isoforms of nitric oxide synthase (NOS) require tetrahydrobiopterin as a cofactor and NADPH as a coenzyme.

Answer 188

A. I **B. II** C. III and IV D. VII E. IX ## Footnote The substantia gelatinosa (Rexed lamina II) is found at all cord levels and is homologous to the spinal trigeminal tract. It is associated with light touch, pain, and temperature sensation, and it integrates input for the ventral and lateral spinothalamic tracts.

Answer 189

**A. an intracranial bruit with heart failure.** B. subarachnoid hemorrhage. C. hydrocephalus. D. developmental delay. E. ocular symptoms. ## Footnote Vein of Galen malformation may be defined as a direct arteriovenous (AV) fistula between choroidal and/or quadrigeminal arteries and an overlying single median venous sac; it is rare, representing only < 1% of all intracrani- al arteriovenous malformations (AVMs). Neonatal patients present with an abrupt onset of high-output cardiac failure; as much as 80% of the cardiac output may pass through the fistula. An audible bruit may be present. An- other type of vein of Galen malformation (VOGM) (presenting with ocular symptoms and developmental delay) is typically thalamic or midbrain with deep drainage to the vein of Galen (VOG).

Answer 190

A. Subarachnoid hemorrhage B. Progressive ascending paraplegic syndrome C. The defi nitive therapy is microsurgical elimination. **D. Tendency to bleed in elderly patients** E. It may represent a vascular anomaly ## Footnote The scan demonstrates an intramedullary cavernoma. These lesions tend to bleed in patients of young age, show a clear sensory level, present with suba- rachnoid hemorrhage or by progressive ascending paraplegic syndrome. The definitive therapy is microsurgical elimination.

Answer 191

B. The arcuate eminence is a prominence on the anterior surface of the petrous portion of the temporal bone corresponding to the position of the superior semicircular canal. ## Footnote The arcuate eminence is a prominence on the anterior surface of the petrous portion of the temporal bone corresponding to the position of the superior semicircular canal.

Answer 192

A. It is a branch of the posterior cerebral artery. B. It supplies the choroid plexus of the third ventricle. C. It supplies the choroid plexus of the lateral ventricles. **D. All of the above** E. None of the above

Answer 193

A. in the third ventricle. **B. in the fourth ventricle.** C. in the lateral ventricle. D. at the cauda equina. E. in none of the above. The calamus scriptorius is an anatomic structure along the inferior part of the rhomboid fossa; the narrow lower end of the fourth ventricle between the two clavae ## Footnote The calamus scriptorius is an anatomic structure along the inferior part of the rhomboid fossa; the narrow lower end of the fourth ventricle between the two clavae.

Answer 194

A. alpha waves. B. beta waves. C. theta waves. **D. delta waves.** E. None of the above Delta waves occur with deep sleep, infancy, and brain disease ## Footnote Delta waves occur with deep sleep, infancy, and brain disease.

Answer 195

A. VII, IX, X B. IX, X C. IX, X, XII D. VII, X **E. VII, IX, XII** The stylohyoid is innervated by VII. The styloglossus is innervated by XII. The stylopharyngeus is innervated by IX. ## Footnote The stylohyoid is innervated by VII. The styloglossus is innervated by XII. The stylopharyngeus is innervated by IX.

Answer 196

**A. C7 plumb line** B. Cobb angle C. Pelvic tilt D. Sacral slope E. None of the above A. The sagittal vertical axis is the distance between the C7 plumb line and the posterosuperior corner of S1 in the sagittal plane ## Footnote The sagittal vertical axis is the distance between the C7 plumb line and the posterosuperior corner of S1 in the sagittal plane.

Answer 197

**A. a painful response is produced by an innocuous mechanical stimulus.** B. a painful response is felt in an amputated limb. C. a painful response is felt on the opposite side of the body. D. there is sensitization of spinocerebellar neurons. E. all of the above may occur. Allodynia is a condition in which a painful response is produced by an innocuous mechanical stimulation. It is the result of sensitization of spinothalamic neurons in the dorsal horn and the failure of descending systems to control the activity of these neurons. Alloesthesia is characterized by a painful stimulus on one side of the body that is thought to be on the other ## Footnote Allodynia is a condition in which a painful response is produced by an innoc- uous mechanical stimulation. It is the result of sensitization of spinothalamic neurons in the dorsal horn and the failure of descending systems to control the activity of these neurons. Alloesthesia is characterized by a painful stim- ulus on one side of the body that is thought to be on the other side.

Answer 198

A. I B. II C. III and IV **D. VII** E. IX Clarke’s nucleus is found at the base of the dorsal horn and corresponds to Rexed VII lamina. Clarke’s column extends from C8 or T1 to about L3. Clarke’s nucleus is homologous to the accessory cuneate nucleus of the medulla. It subserves unconscious proprioception from the muscle spindles and Golgi tendon organs and is the origin of the dorsal spinocerebellar tract ## Footnote Clarke’s nucleus is found at the base of the dorsal horn and corresponds to Rexed VII lamina. Clarke’s column extends from C8 or T1 to about L3. Clarke’s nucleus is homologous to the accessory cuneate nucleus of the medulla. It subserves unconscious proprioception from the muscle spindles and Golgi tendon organs and is the origin of the dorsal spinocerebellar tract.

Answer 199

A. Occipital encephaloceles are the most common type. B. Frontoethmoidal (sincipital) are the most common type in southeast Asia and among Australian aborigines. C. Parietal encephaloceles are associated with Chiari II malformation in up to one-third of cases. D. Basal encephaloceles are associated with defects along the sphenoid bone. **E. Children with basal encephaloceles have a low risk of developing meningitis** Basal encephaloceles should be treated as early as possible. Children with basal encephaloceles in the nasopharynx are at signifi cant risk of developing meningitis ## Footnote Basal encephaloceles should be treated as early as possible. Children with basal encephaloceles in the nasopharynx are at significant risk of developing meningitis

Answer 200

A. the thalamus and the globus pallidus. **B. the caudate nucleus and the corpus striatum**. C. the caudate and the thalamus. D. the thalamus and the putamen E. None of the above The anterior limb of the internal capsule (on horizontal section) can be found between the caudate nucleus and the corpus striatum (globus pallidus and putamen). Clinically important tracts lie in the genu and posterior limb. The posterior limb (on horizontal section) can be found between the thalamus and the corpus striatum (globus pallidus and putamen). The posterior limb of the internal capsule contains corticospinal fi bers. ## Footnote The anterior limb of the internal capsule (on horizontal section) can be found between the caudate nucleus and the corpus striatum (globus pallidus and putamen). Clinically important tracts lie in the genu and posterior limb. The posterior limb (on horizontal section) can be found between the thalamus and the corpus striatum (globus pallidus and putamen). The posterior limb of the internal capsule contains corticospinal fibers.

Answer 201

A.A B.B. C.C **D.D** E.E

Answer 202

**A.A** B.B. C.C D.D E.E

Answer 203

A.A **B.B.** C.C D.D E.E

Answer 204

A.A B.B. **C.C** D.D E.E

Answer 205

A. It emerges inferior to the inferior obliquus capitis muscle. B. It is accompanied by the occipital artery. C. It is a sensory nerve. **D. All of the above** E. None of the above The greater occipital nerve is a sensory nerve from the dorsal ramus of C2. ## Footnote The greater occipital nerve is a sensory nerve from the dorsal ramus of C2.

Answer 206

A. Aspirin inhibits both cyclooxygenase (COX) isoforms. B. Arachidonic acid is a substrate for production of ceramide. **C. Thromboxane synthesis inhibitors lead to depletion of arachidonic acid.** D. Arachidonic acid is a substrate for COX I. E. Prostaglandin H2PGH2 is a product of the COX enzyme. Thromboxane synthesis inhibitors lead to a buildup of arachidonic acid ## Footnote Thromboxane synthesis inhibitors lead to a buildup of arachidonic acid.

Answer 207

A. subthalamic nucleus. B. substantia nigra pars compacta. **C. substantia nigra pars reticulata.** D. globus pallidus interna. E. globus pallidus externa C. The lateral portion of the substantia nigra pars reticulata (SNpr) is connected with cortical and brainstem areas that control eye movements. SNpr is GABAergic and inhibitory to the VLm (medial part of the ventrolateral thalamus) and VAmc (magnocellular part of the ventral anterior thalamus) ## Footnote The lateral portion of the substantia nigra pars reticulata (SNpr) is connect- ed with cortical and brainstem areas that control eye movements. SNpr is GABAergic and inhibitory to the VLm (medial part of the ventrolateral thala- mus) and VAmc (magnocellular part of the ventral anterior thalamus).

Answer 208

**A. Dorsal lateral sulcus** B. Dorsal intermediate sulcus C. Ventral lateral sulcus D. Dorsal median sulcus E. Ventral intermediate sulcus A. The dorsal lateral sulcus receives the dorsal roots ## Footnote The dorsal lateral sulcus receives the dorsal roots.

Answer 209

A. Biopsy is usually indicated to confi rm the diagnosis. B. Hyperfractionated radiation therapy has not been shown to improve survival. C. It represents 30% of pediatric CNS tumors. **D. There is no proven chemotherapeutic regimen.** E. Most lesions will regress spontaneously D. The scan shows a diff usely enhancing brainstem glioma. Biopsy is usually not recommended in this case. Hyperfractionated radiation therapy has been shown to improve survival. Brainstem gliomas represent 10–20% of childhood CNS tumors. There are currently no proven chemotherapeutic regimens. ## Footnote The scan shows a diffusely enhancing brainstem glioma. Biopsy is usual- ly not recommended in this case. Hyperfractionated radiation therapy has been shown to improve survival. Brainstem gliomas represent 10–20% of childhood CNS tumors. There are currently no proven chemotherapeutic regimens.

Answer 210

A. PT = PI + SS **B. PI = PT + SS** C. SS = PI + PT D. PT = PI − SS E. SS = PI ÷ PT Pelvic incidence: the angle between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle axis of the femoral heads. It is an anatomical parameter, unique to each individual, independent of the spatial orientation of the pelvis. Sacral slope: the angle between the superior plate of S1 and a horizontal line. Pelvic tilt: the angle between the line connecting the midpoint of the sacral plate to the axis of the femoral heads, and the vertical. ## Footnote Pelvic incidence: the angle between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle axis of the femoral heads. It is an anatomical parameter, unique to each individual, independent of the spatial orientation of the pelvis. Sacral slope: the angle between the superior plate of S1 and a horizontal line. Pelvic tilt: the angle between the line connecting the midpoint of the sacral plate to the axis of the femoral heads, and the vertical.

Answer 211

A. Men may not seek early attention despite loss of libido and potency, headache, or fatigue. B. When visual loss or disturbing endocrine symptoms are present most seek medical attention. C. A useful endocrine test is determination of the basal serum prolactin level. D. The normal level ranges from 5 to 20 ng/mL. **E. When the level of prolactin is normal post-treatment, ovulation and menstruation return in < 50% of women in galactorrhea cases** E. The MRI represents a midsagittal section demonstrating a large sellar and suprasellar mass that is compressing the optic chiasm. Slightly elevated prolactin level may be secondary to the stalk eff ec ## Footnote The MRI represents a midsagittal section demonstrating a large sellar and suprasellar mass that is compressing the optic chiasm. Slightly elevated pro- lactin level may be secondary to the stalk effect.

Answer 212

A. Exercise B. Stress C. Sleep D. Pregnancy **E. Delivery**

Answer 213

A. 10% B. 20% C. 40% **D. 70%** E. 90%

Answer 214

A. It is also called dysplastic gangliocytoma of the cerebellum. **B. There is demyelination of granular cell layer of the cerebellum.** C. There is thickening of one or more cerebellar folia. D. Calcifi cation and hydrocephalus may occur in this disorder. E. A laminated pattern of folia on T2-MRI scans is suggestive of the disease B. Lhermitte–Duclos disease is an uncommon cerebellar dysplasia that is characterized by hypertrophy of granular-cell neurons, and axonal hypermyelination in the molecular layer. Also known as dysplastic gangliocytoma of the cerebellum, it may occur in the setting of Cowden disease caused by a PTEN germline mutation ## Footnote Lhermitte–Duclos disease is an uncommon cerebellar dysplasia that is char- acterized by hypertrophy of granular-cell neurons, and axonal hypermyeli- nation in the molecular layer. Also known as dysplastic gangliocytoma of the cerebellum, it may occur in the setting of Cowden disease caused by a PTEN germline mutation.

Answer 215

**A. Unilateral symptoms** B. Sensory defi cit C. Decreased corneal refl ex D. All of the above E. None of the above A. There is no sensory defi cit and no decrease in corneal refl ex. There are no other symptoms in the other cranial nerve ## Footnote There is no sensory deficit and no decrease in corneal reflex. There are no other symptoms in the other cranial nerves.

Answer 216

A. cranioplasty. **B. endovascular procedures.** C. topical wound dressings. D. vasospasm in the ICU. E. spinal fusion. B. The liquid embolic agent n-butyl cyanoacrylate is used in interventional neuroradiology. The embolic agents that are particulate in nature include polyvinyl alcohol, platinum coils, and silk thread. ## Footnote The liquid embolic agent n-butyl cyanoacrylate is used in interventional neuroradiology. The embolic agents that are particulate in nature include polyvinyl alcohol, platinum coils, and silk thread.

Answer 217

A. 15. B. 14. **C. 13.** D. 12. E. 11 The Glasgow Coma Scale score (GCS score) in this case would be 13. Eyes open to speech (3), the patient is confused (4), and he obeys motor commands (6) ## Footnote The Glasgow Coma Scale score (GCS score) in this case would be 13. Eyes open to speech (3), the patient is confused (4), and he obeys motor commands (6)

Answer 218

A. Midcervical **B. Upper thoracic** C. Lower thoracic D. Lumbar E. Sacra ## Footnote The ciliospinal center of Budge is found in the lateral horn at T1. This is a sympathetic nucleus that innervates the radial muscle of the iris (dilator pu- pillae) and the nonstriated superior and inferior (Müller) muscles.

Answer 219

A. Cimetidine B. Chloramphenicol C. Valproic acid D. Uremia **E. Aspirin** ## Footnote Aspirin decreases all anticonvulsant levels.

Answer 220

**A. Pain and temperature of the body** B. Pain and temperature of the face C. Horner’s syndrome D. Falling E. None of the above ## Footnote Posterior inferior cerebellar artery (PICA) syndrome causes decreased contralateral pain and temperature of the body.

Answer 221

A. Clay shoveler’s fracture B. Wedge fracture **C. Teardrop fracture** D. Chance fracture E. None of the above ## Footnote Teardrop fractures occur when a fracture occurs on the anteroinferior edge of the vertebral body. The injury is due to hyperflexion and is unstable. Tear- drop fractures are associated with anterior cord syndrome.

Answer 222

A. Lacerations in the gland with attendant subcapsular bleeding make it difficult if not impossible to detect the subtle differences between the normal gland and a small tumor. **B. Prolactin microadenomas are usually situated medially in the gland.** C. Larger pituitary tumors usually erode the floor of the sella turcica, and in these cases the tumor may extrude into the operative wound upon removal of the fl oor of the sella and opening of the dura mater. D. Frequently, the pituitary gland is compressed and flattened against the dorsum sellae or diaphragma sellae by tumor. E. Reported incidence of postoperative CSF rhinorrhea is ~3%.

Answer 223

A. Pia **B. Dura** C. Arachnoid D. Glia E. Ependyma ## Footnote Dura and blood vessels are formed from mesoderm.

Answer 224

A. meningioma. B. oligodendroglioma. **C. astrocytoma.** D. ependymoma. E. None of the above ## Footnote The most common primary septal tumor is astrocytoma.

Answer 225

A. AICA B. PICA **C. SCA** D. Satellite veins E. None of the above ## Footnote The superior cerebellar artery is the most commonly conflicting artery in trigeminal neuralgia.

Answer 226

**A. vertebrobasilar ischemia.** B. controlling ICP C. vasospasm. D. tumor biology. E. None of the above ## Footnote The ELANA technique (excimer laser-assisted nonocclusive anastomosis) may be used to anastomose arteries.

Answer 227

A. metastatic disease. **B. jumped facet.** C. burst fracture. D. teardrop fracture. E. epidural abscess. ## Footnote This MRI scan demonstrates a unilateral jumped facet with rotation in the cervical cord, compromising the spinal canal.

Answer 228

A. Spetzler–Martin grade 3 B. Spetzler–Martin grade 3A C. Spetzler–Martin grade 4 **D. Spetzler–Martin grade 4A** E. Spetzler–Martin grade 5 ## Footnote This particular AVM is best-graded 4A. Its medium size (2), eloquent location (1), and deep drainage (1) place it as a Spetzler–Martin grade 4. The fact that it has stenotic venous drainage gives it a subclassification of 4A

Answer 229

A. Apneustic **B. Biot** C. Central neurogenic hyperventilation D. Kussmaul E. Cheyne–Stokes ## Footnote Biot (irregular breathing) is caused by a lesion in the dorsomedial medulla.

Answer 230

A. Globus pallidus externa, posterior limb of the internal capsule **B. Globus pallidus interna, posterior limb of the internal capsule** C. Globus pallidus externa, anterior limb of the internal capsule D. Globus pallidus interna, anterior limb of the internal capsule E. None of the above ## Footnote The anterior choroidal artery supplies the internal globus pallidus, posterior limb of the internal capsule, and temporal horn of the choroid plexus.

Answer 231

A. is due to repetitive usage. B. causes aching and fatiguing of the muscles involved. C. causes nocturnal exacerbations. **D. exhibits numbness in the palm area.** E. is a better candidate for surgery ## Footnote Pronator teres syndrome is different from carpal tunnel syndrome in that patients with pronator teres syndrome exhibit numbness in the palm, and nocturnal exacerbations are rare.

Answer 232

A. Weakness in the upper extremities B. Loss of temperature sensation in lower extremities **C. Horner’s sign** D. Gait disturbances E. Diplopia ## Footnote The MRI scan represents a brain midsagittal section demonstrating descent of the cerebellar vermis or tonsils consistent with a Chiari malformation, given the age of the patient and the absence of other findings (e.g., hydro- cephalus or medullary kinking), this most likely represents a Chiari type 1 malformation.

Answer 233

A. Herniation of cerebellar hemispheres B. CSF leak **C. Respiratory depression** D. Vascular injury to the posterior inferior cerebellar artery E. Postoperative wound infection

Answer 234

A. Patients presenting with pain generally respond well to surgery. B. Weakness is most likely to improve with surgery as compared with pain and sensory defi cits. **C. Sensation may improve when the posterior columns are unaff ected.** D. The most favorable results occurred in patients with cerebellar syndrome. E. Factors that correlate with a worse outcome include ataxia, scoliosis, and symptoms lasting longer than 2 years

Answer 235

A. V1only **B. V2 only** C. V3 only D. V2 and V3 E. V1, V2, and V3 ## Footnote Although it is true that the pain starts at V2 (the lower side of the nose) and then involves V3 and V1, it is only necessary to treat the trigger zone.

Answer 236

A. Agraphia without alexia B. Left–right confusion C. Finger agnosia D. Acalculia **E. Astereognosis** ## Footnote Gerstmann’s syndrome is caused by a dominant parietal lobe lesion (angu- lar gyrus) and includes agraphia without alexia (patient can read but cannot write). Astereognosis is also caused by dominant parietal lobe lesions but is not part of Gerstmann’s syndrome.

Answer 237

A. Fibrous dysplasia B. Osteoma C. Eosinophilic granuloma D. Giant cell tumor **E. Epidermoid** ## Footnote Epidermoids of the skull show a lytic defect with a scalloped, sclerotic rim. They are slow growing and rarely show malignant transformation.

Answer 238

A. Cochlear B. Glossopharyngeal C. Vagus D. Accessory **E. Hypoglossal**

Answer 239

A. Dreaming occurs. **B. Nightmares occur.** C. There is decreased duration with hypothyroidism. D. Somnambulism occurs. E. There is increased duration after sleep deprivation. ## Footnote Nightmares occur during REM sleep; night terrors may occur in either stage 3 or 4 sleep. Stage 4 sleep is associated with delta waves.

Answer 240

**A. dopamine.** B. norepinephrine. C. serotonin. D. dopamine and norepinephrine. E. None of the above

Answer 241

A. Flexor digitorum profundus B. Flexor pollicis longus C. Pronator quadratus **D. All of the above** E. None of the above

Answer 242

A. Inferior petrosal sinus **B. Jugular bulb** C. Sigmoid sinus D. Transverse sinus E. PICA ## Footnote A high-riding jugular bulb may be encountered during the drilling portion and should be tamponaded with hemostatic products and cottonoids.

Answer 243

A. Subforniceal organ **B. Subcommissural organ** C. Area postrema D. All of the above E. None of the above ## Footnote The subcommissural organ is the only circumventricular organ with an intact blood–brain barrier (BBB).

Answer 244

A. penicillin. **B. captopril.** C. steroids. D. All of the above E. None of the above ## Footnote Dysgeusias are particularly prevalent in the elderly and are often associated with the use of antihypertensives (e.g., captopril).

Answer 245

A. Observation B. Surgical excision **C. Gamma knife** D. Partial surgical treatment E. Lumbar drainage ## Footnote Gamma knife treatment is the best mode of therapy for an AVM that is small- er than 3 cm and located in an eloquent area. The angiogram shows a small subcortical right parietal arteriovenous malformation with filling vessel aris- ing from a branch of the right middle cerebral artery. Venous drainage is not- ed into the upper sagittal sinus.

Answer 246

A. Cerebral atrophy B. Wernicke’s encephalopathy C. Central pontine myelinolysis **D. Foster Kennedy’s syndrome** E. Marchiafava–Bignami’s disease ## Footnote Foster–Kennedy syndrome is usually caused by an olfactory groove or medial-third sphenoid wing tumor (usually meningioma). The classic triad is anosmia (ipsilateral), central scotoma (ipsilateral), and papilledema (contralateral).

Answer 247

A. Early Alzheimer’s disease **B. Pick’s disease** C. Creutzfeldt–Jakob Disease D. Huntington’s disease E. Diff use Lewy body dementia ## Footnote Pick’s disease is characterized by severe focal atrophy commonly in the fron- tal and temporal lobes. This results in mental status and personality changes occurring in Pick’s patients. Pick bodies are positive for tau protein.

Answer 248

A. They are a triphasic potential. **B. They typically last 10–15 milliseconds.** C. They are caused by denervation. D. They are seen with poliomyelitis, ALS, and peripheral nerve injury. E. They may be associated with positive sharp waves. ## Footnote Fibrillation potentials are triphasic and last 1–5 ms caused by the activity of one fiber.

Answer 249

A. stage 1 sleep. **B. stage 2 sleep.** C. stage 3 sleep. D. stage 4 sleep. E. REM sleep. ## Footnote Sleep spindles (the burst described) and K complexes (sharp slow waves of high amplitude) are characteristic of stage 2 sleep.

Answer 250

A. Petrous bone B. Hyperostosis C. Anterior clinoid process **D. Posterior clinoid process** E. None of the above ## Footnote The bony promontory seen in the picture is the posterior clinoid process and may be drilled carefully to expose the neck of the aneurysm.

Answer 251

A. a direct branch of the C5 root. B. a branch from the middle trunk. C. a branch from the posterior cord. **D. a branch from the superior trunk.** E. None of the above ## Footnote The suprascapular nerve is trapped in the suprascapular notch. This nerve is the branch of the superior trunk. Atrophy of the supraspinatus and infraspi- natus can result.

Answer 252

A. III B. IV **C. VI** D. VII E. XII ## Footnote The abducens nerve crosses the medial lemniscus on exiting the brainstem.

Answer 253

A. 50 mL/100 mg/min. **B. 50 mL/100 g/min.** C. 50 mL/mg/min. D. 50 mL/g/min. E. None of the above ## Footnote The correct units are 50 mL/100 g/min.

Answer 254

A. Bell’s palsy B. Familial dysautonomia C. Raeder’s paratrigeminal syndrome **D. All of the above** E. None of the above

Answer 255

**A. attention.** B. memory. C. visuoconstructive ability. D. executive function. E. cognitive function. ## Footnote Removal of frontal meningiomas may improve attentional functions. There are minimal differences in memory, visuoconstructive abilities, or executive functions.

Answer 256

A. causes decreased secretion of all pituitary hormones. B. is independent from the hypophyseal portal system. C. is independent from damage to hypothalamic neurons. D. causes increased release of luteinizing hormone (LH). **E. causes increased secretion of prolactin (PRL).** ## Footnote The secretion of prolactin by lactotroph cells is inhibited by dopamine released by hypothalamic neurons.

Answer 257

A. there is increased activity of STN (subthalamic) neurons. B. there is increased activity of SNpr (pars reticulata) neurons. **C. there is decreased activity of SNpr neurons.** D. there is increased activity of GPe (globus pallidus pars externa) neurons. E. All of the above occur ## Footnote The substantia nigra pars reticulata neurons related to saccadic eye move- ments decrease their activity during the saccade.

Answer 258

A. They have three to fi ve phases. B. They last from 5 to 15 milliseconds. C. They are associated with nerve fiber irritability. **D. They are not visible through the skin.** E. They may be associated with hypocalcemia, hypothermia, and nerve entrapments.

Answer 259

**A. Neural mechanisms regarding associative learning rarely are conserved between different species.** B. Calexcitin binds guanosine triphosphate (GTP), which is important in cell signaling. C. At the endoplasmic reticulum membrane, it has been shown to bind to the ryanodine receptor with high affi nity. D. Calexcitin directly inactivates voltage-dependent potassium currents. E. It is a high-affi nity substrate for the -isozyme of protein kinase C (PKC). ## Footnote Research with model systems of seemingly disparate species (i.e., marine snail and albino rat) suggest that neural mechanisms involved in associative learning may be highly conserved across species.

Answer 260

A. Anti-Hu antibodies and Lambert-Eaton myasthenic syndrome B. Lambert-Eaton myasthenic syndrome and limbic encephalitis C. Ectopic adrenocorticotropic hormone (ACTH) secretion D. Syndrome of inappropriate antidiuretic hormone (SIADH) **E. All of the above**

Answer 261

A. hypocalcemia. B. hypokalemia. **C. hypothermia.** D. hypothyroidism. E. subendocardial ischemia. ## Footnote Hypothermia is characterized by J-point elevation.

Answer 262

**A. Anterior encephaloceles** B. Parietal encephaloceles C. Basal encephaloceles D. Occipital encephaloceles E. Encephaloceles without nasal deformities ## Footnote Anterior encephaloceles are compatible with normal intelligence in the ma- jority of patients. Atretic encephaloceles also appear not to influence intel- lectual development and also have a low incidence of hydrocephalus.

Answer 263

**A. TP53** B. PTEN C. EGFR D. All of the above E. None of the above ## Footnote Giant cell glioblastoma is shown in the slide. The hallmark of giant cell glio- blastoma is predominance on multinucleated giant cells and a high frequen- cy of the TP53 mutation.

Answer 264

A. Microvascular proliferation B. Necrosis C. Pseudopalisading **D. All of the above** E. None of the above ## Footnote These features should not necessarily prompt the diagnosis of glioblastoma.

Answer 265

A. Angular gyrus **B. Supramarginal gyrus** C. Middle temporal gyrus D. Superior parietal lobule E. None of the above ## Footnote The supramarginal gyrus is at the posterior reach of the sylvian fissure.

Answer 266

**A. Medulla** B. Pons C. Hypothalamus D. Thalamus E. Midbrain ## Footnote Avellis’s syndrome is caused by a brainstem lesion that limits vagal innerva- tion unilaterally, resulting in ipsilateral paralysis of the vocal cord and soft palate and loss of sensitivity to pain and temperature in the contralateral leg, trunk, arm, and neck. This syndrome is also called ambiguospinothalamic paralysis.

Answer 267

A. glutamate agonist. B. glutamate antagonist. C. dopamine agonist. D. GABA agonist. **E. GABA antagonist.** ## Footnote Bicuculline is a GABA-A antagonist. Muscimol is a GABA-A agonist. Ky- nurenate is a glutamate antagonist. Picrotoxin is a GABA inhibitor.

Answer 268

A. It may be associated with a footdrop. **B. It is a condition of disordered myelination from decreased production of ** peripheral myelin protein 22 (PMP22). C. It is the most common inherited peripheral neuropathy. D. It is associated with a mutation on chromosome 17. E. It is characterized by peroneal muscle atrophy. ## Footnote There is increased production of PMP22 in Charcot–Marie–Tooth disease.

Answer 269

A. trigeminal motor nucleus and the spinal trigeminal tract. B. dorsal aspect of the principle sensory nucleus and the spinal trigeminal tract. **C. ventral aspect of the principle sensory nucleus and the spinal trigeminal tract.** D. ventral aspect of the principle sensory nucleus and the mesencephalic tract. E. dorsal aspect of the principle sensory nucleus and the mesencephalic tract. ## Footnote Neurons in the spinal nucleus and in the ventral parts of the chief sensory nucleus give rise to the crossed ventral trigeminothalamic tract.

Answer 270

A. Motion is perceived by an object’s change of position on the retina. B. The sensation of movement is known as the phi phenomenon. C. Images that change positions more than 15 times per second are indistinguishable from continuous motion. **D. The motion system is disabled at rates below 100 Hz.** E. There is no physical process occurring on the retina that corresponds to the perceived sensation of motion. ## Footnote In stroboscopic illumination at flicker rates below 15 Hz, the motion system is disabled. This explains why nightclub dancers are seen as moving discon- tinuously under a strobe light.

Answer 271

A. Rubrospinal tract B. Medial vestibulospinal tract **C. Tectospinal tract** D. All of the above E. None of the above ## Footnote The tectospinal tract decussates in the dorsal tegmental decussation. Tec- tospinal fibers originate from deeper layers of the superior colliculus and distribute to cervical cord levels. Rubrospinal fibers decussate in the ventral tegmental decussation.

Answer 272

**A. It is the major predictor of later tumor recurrence.** B. It demands use of special instruments. C. It will more likely result in anosmia postoperatively. D. All of the above E. None of the above ## Footnote In the Royal Melbourne Hospital series of paranasal sinus involvement treat- ed by craniofacial resection, sphenoid sinus involvement was the major pre- dictor of later tumor recurrence.

Answer 273

A. Rods B. Cones C. Horizontal cells D. Amacrine cells **E. Bipolar cells** ## Footnote Bipolar cells serve as interneurons between photoreceptor cells and ganglion cells.

Answer 274

A. GFAP. B. S-100. C. vimentin. **D. All of the above** E. None of the above

Answer 275

A. the straight sinus. **B. the vein of Galen.** C. the confl uence of sinuses. D. the inferior sagittal sinus. E. None of the above

Answer 276

A. It has been linked to severe defi ciency of myelin-specifi c lipids. B. It is X-linked recessive in the classical form. **C. The connatal form (type II) is milder than the classical form.** D. It manifests as a “tigroid” pattern of perivascular myelin preservation on MRI. E. Rare instances of female cases have been described. ## Footnote The connatal form (type II) is clinically more severe and symptoms begin in the neonatal period. Pelizaeus–Merzbacher disease (PMD) results from mu- tations affecting the gene for proteolipid protein (PLP).

Answer 277

A. Reticulocerebellar B. Vestibulocerebellar C. Trigeminocerebellar **D. Pontocerebellar tract** E. Olivocerebellar tract ## Footnote The pontocerebellar tract passes to the cerebellum via the middle cerebellar peduncle. The ventral spinocerebellar tract and the tectocerebellar tract pass through the superior cerebellar peduncle.

Answer 278

A. The fl occulonodular lobe receives input from the vestibular nuclei. B. The anterior lobe receives input from the spinocerebellar tracts. **C. The vermis sends fi bers to the VL thalamus and motor cortex.** D. The intermediate zone functions with posture, tone, and ipsilateral limb movements. E. A lesion of the interposed nuclei causes intention tremor. ## Footnote The lateral zone (dentate) sends fibers to the VL thalamus and motor cortex (area 4). A lesion of the anterior lobe may cause slight hyperreflexia.

Answer 279

**A. Dendrodendritic** B. Axodendritic C. Axoaxonic D. Axosomatic E. Dendroaxonic ## Footnote Dendrodendritic synapses have been found in the olfactory bulb and have been shown to be inhibitory; the granule cells processes make synaptic con- tacts with dendrites of mitral cells. Axodendritic synapses are excitatory. Axosomatic synapses are inhibitory, and a classic example is the cerebellar basket cell contacting the Purkinje cell.

Answer 280

A. It is a small cell with a compact dendritic tree. **B. It represents a minority of the total ganglion cell number.** C. It projects to layer 4C in the striate cortex. D. It is involved with color processing. E. It has low contrast sensitivity and high acuity ## Footnote The parvocellular system of the dorsal lateral geniculate nucleus makes up about 80% of the total ganglion cell number.

Answer 281

A. It manifests as a decrease in end tidal CO2. B. Air should be aspirated from the right atrium if it occurs. C. The patient should be placed in the left lateral decubitus position. D. The head should be lowered if possible. **E. End tidal CO2 changes cannot precede precordial Doppler changes.** ## Footnote During a neurosurgical procedure, a sudden decrease in end tidal CO2 sug- gests venous air embolus and may even precede the appreciation of changes by the precordial Doppler.

Answer 282

A. caudate vein. B. septal vein. C. basal vein of Rosenthal. D. internal cerebral vein. **E. thalamostriate vein.** ## Footnote These structures run in the floor of the body of the lateral ventricle.

Answer 283

**A. Median nerve, brachial artery, biceps brachii tendon, radial nerve** B. Median nerve, biceps brachii tendon, radial nerve, brachial artery C. Biceps brachii tendon, median nerve, radial nerve, brachial artery D. Brachial artery, biceps brachii tendon, radial nerve, median nerve E. None of the above ## Footnote The contents of the cubital fossa from medial to lateral are the median nerve, brachial artery, biceps brachii tendon, and radial nerve.

Answer 284

A. Pectoralis major B. Subscapularis C. Teres major **D. Teres minor** E. Latissimus dorsi ## Footnote The teres minor rotates the arm laterally.

Answer 285

A. Vein of Galen B. Basal vein of Rosenthal **C. Internal cerebral vein** D. Thalamostriate vein E. Caudate vein ## Footnote The internal cerebral vein position can be confirmed by superimposing the angiogram of the medial posterior choroidal artery with the venous phase. The internal cerebral vein and the medial posterior choroidal artery occupy the same position when the arterial and venous phase are superimposed. Both of these structures course within the cistern of the velum interpositum.

Answer 286

A. Basilar **B. Anterior spinal** C. Vertebral D. PICA E. AICA

Answer 287

A. excitatory control of cardiac function. B. inhibitory control of cardiac function. C. excitatory control of respiratory function. **D. inhibitory control of respiratory function.** E. None of the above ## Footnote The Botzinger complex is the principle source of reciprocal inhibition in the respiratory network. It comprises a cluster of cells at the rostral-most tip of the ventral respiratory group.

Answer 288

A. Superior trunk B. Medial trunk C. Lateral cord **D. Posterior cord** E. Medial cord ## Footnote The posterior cord gives rise to the upper subscapular, lower subscapular, and thoracodorsal nerves. The latissimus dorsi is innervated by the thoracodorsal nerve. The subscapularis muscle is innervated by the upper and lower sub- scapular nerve. The teres major is innervated by the lower subscapular nerve.

Answer 289

**A. The majority of adults with this disease present with ischemia.** B. The age of onset of symptoms displays a bimodal distribution. C. It is of unknown etiology. D. It involves progressive stenosis of the supraclinoid carotid arteries with the concomitant formation of rich collaterals at the skull base. E. It is associated with Down syndrome and neurofi bromatosis. ## Footnote The vast majority of children present with ischemic symptoms (transient ischemic attacks (TIAs), extremity weakness), whereas adults typically pres- ent with hemorrhage.

Answer 290

A. It is eff ective in generalized tonicoclonic seizures. B. It is ~90% protein bound. **C. It has a long half-life.** D. It may be associated with platelet dysfunction. E. It may result in liver dysfunction. ## Footnote Valproic acid has a short half-life (~ 8 hours). Association with platelet dys- function should alert the surgeon to the possibility of bleeding problems, especially in epilepsy cases.

Answer 291

A. Enflurane **B. Isoflurane** C. Nitrous oxide D. Halothane E. Ketamine ## Footnote Isoflurane allows patients to emerge from anesthesia faster, and there is less hepatic effect from this agent. In addition, isoflurane produces the least in- crease in cerebral blood flow (CBF) of inhalational anesthetics.

Answer 292

A. the frontal horn. B. the temporal horn. **C. the atrium.** D. the occipital horn. E. None of the above ## Footnote The glomus is a prominent tuft of choroid plexus found in the atrium.

Answer 293

A. Axillary, musculocutaneous B. Median, musculocutaneous **C. Axillary, radial, ulnar** D. Median, radial, ulnar E. Median, radial ## Footnote The axillary nerve passes posteriorly around the surgical neck of the humer- us. The radial nerve lies in the radial groove of the middle of the shaft of the humerus. The ulnar nerve passes behind the medial epicondyle. All three of these nerves are susceptible to humerus fractures since they lie in close con- tact with bone.

Answer 294

A. precentral gyrus. B. postcentral gyrus. **C. premotor cortex.** D. prefrontal cortex. E. cingulated gyrus. ## Footnote The premotor area plays a role in programming and sequencing learned complex movements.

Answer 295

A. Vein of Galen B. Basal vein of Rosenthal C. Internal cerebral vein D. Straight sinus **E. Precentral cerebellar vein**

Answer 296

**A. 5 Hz** B. 10 Hz C. 15 Hz D. 20 Hz E. 25 Hz ## Footnote Theta activity has a frequency of 4–7 Hz. Other common electroenceph- alographic (EEG) rhythms are delta (0–3 Hz), alpha (8–13 Hz), and beta (> 13 Hz).

Answer 297

A. Motor nucleus of V (trigeminal) **B. Mesencephalic nucleus of V** C. Sensory nucleus of V D. Red nucleus E. Locus ceruleus ## Footnote The mesencephalic nucleus of the trigeminal nerve has pseudounipolar neu- rons. The mesencephalic nucleus extends from the pons to the upper mid- brain. It receives input from muscle spindles and pressure receptors.

Answer 298

A. fi rst-order neurons of the ventral spinocerebellar tract. **B. second-order neurons of the ventral spinocerebellar tract.** C. fi rst-order neurons of the dorsal spinocerebellar tract. D. second-order neurons of the dorsal spinocerebellar tract. E. None of the above ## Footnote These second-order neurons will give rise to axons that enter the cerebellum via the superior cerebellar peduncle. The ventral spinocerebellar tract con- veys efference copies of motor commands for the lower extremities.

Answer 299

A. represent corticotrope cells. **B. stain purple after periodic acid-Schiff (PAS) staining.** C. represent somatotrope cells. D. lack cytoplasmic granules. E. can only be acidophils or basophils ## Footnote Chromophobic cells lack cytoplasmic granules. They represent acidophil or basophil cells after the release of hormone-containing granules. They have no stain reaction after PAS stain.

Answer 300

A. anterior resection. B. posterior resection. C. lateral resection. **D. medial resection.** E. None of the above ## Footnote The extent of mesiobasal resection determines the outcome after temporal lobectomy for intractable complex partial seizures.

Answer 301

A. Huntington’s chorea. B. chorea gravidarum. C. senile chorea. D. hysterical chorea. **E. Sydenham’s chorea.** ## Footnote Sydenham’s chorea is the most common type of chorea. Also known as St. Vi- tus’s dance, this chorea occurs mainly in young females after a bout of rheu- matic fever.

Answer 302

A. myopathy. B. susceptibility to infection. C. posterior subcapsular cataracts. **D. All of the above** E. None of the above ## Footnote This is decadron. A postoperative course of an H2-receptor blocker is indicat- ed for patients on glucocorticoid treatment.

Answer 303

A. The ulnar artery is superfi cial to it. B. The median nerve is deep to it. C. The ulnar nerve is superfi cial to it. **D. All of the above** E. None of the above

Answer 304

A. Thalamotomy **B. Ventralis intermedius stimulation** C. GPi stimulation D. Any of the above E. None of the above ## Footnote Ventralis intermedius (Vim) stimulation is the procedure of choice when contralateral thalamotomy has been performed or is anticipated.

Answer 305

A. meningioma. B. arteriovenous malformations. **C. anaplastic astrocytoma.** D. ependymomas. E. None of the above ## Footnote Temozolomide (TMZ) is an orally administered chemotherapeutic (alkyl- ating) agent with minimal side effects that readily crosses the blood–brain barrier and is approved for treating anaplastic astrocytomas.

Answer 306

A. polyneuropathy. B. cervical radiculopathy. C. myopathy. **D. S1 radiculopathy.** E. median nerve compression ## Footnote The H-reflex is a submaximal stimulation of mixed motor-sensory nerves, not enough to cause a direct motor response. The H-reflex is the electrical representation of the tendon reflex circuit.

Answer 307

A. Lipofuscin accumulation **B. Lewy bodies** C. Marinesco bodies D. Alzheimer changes E. Colloid inclusions ## Footnote The most common and pronounced aging effect on the brain is cell loss.

Answer 308

**A. Dorsal column** B. Spinospinal C. Ventral spinocerebellar D. Dorsal spinocerebellar E. Spinothalamic ## Footnote Stereognosis is an important function of the dorsal column–medial lemnis- cal system.

Answer 309

A. Pressure gradients between left and right sides of the brain and supra- and infratentorial compartments may be present. B. The incidence of hemorrhage after insertion is about 1%. **C. Irrigating the tubing decreases the contamination rate of ventricular catheters.** D. Decreased intracranial compliance is suggested when the “b wavelet” is greater than the “a wavelet.” E. There is no clear consensus as to whether to use prophylactic antibiotics. ## Footnote Irrigation of fluid-coupled monitoring systems increases the infection rate nearly threefold. Thus irrigation, if necessary, should be performed infre- quently and with exquisite sterile technique.

Answer 310

A. In the pyramidal decussation, arm areas of cortex cross rostral to those that arise from leg areas. B. It receives contribution from somatomotor cortex, prefrontal regions, and parietal areas. C. Glutamate is present in cortical eff erent fi bers that project to the spinal cord. D. Leg fi bers are lateral to arm fi bers at most levels of this particular tract. **E. Area 4 and postcentral gyrus fi bers terminate in the same spinal cord lamina.** ## Footnote Area 4 fibers terminate in laminae VI–IX, whereas fibers starting in laminae IV and V project to the postcentral gyrus via the spino-thalamic tract. The anterior corticospinal tract is an uncrossed tract in the (medial) ventral cord and terminates on lamina VII.

Answer 311

A. The inferior parietal lobule B. Broca’s area C. Wernicke’s area D. The primary auditory cortex **E. The paracentral lobule** ## Footnote The paracentral lobule is supplied by branches from the anterior cerebral artery.

Answer 312

A. the genu of the corpus callosum. B. the cingulate gyrus. C. the pericallosal artery. **D. the splenium of the corpus callosum.** E. None of the above

Answer 313

A. 13 degrees. B. 30 degrees. C. 100 degrees. **D. 130 degrees.** E. 180 degrees.

Answer 314

A. Anteromedial B. Anterolateral C. Posteromedial **D. Posterolateral** E. None of the above ## Footnote The sensorimotor GPi is located in the posterolateral part of the nucleus.

Answer 315

**A. The majority of these lesions arise from a ventral nerve root.** B. 10 to 15% extend through the dural root sleeve. C. The fourth through sixth decades represent the peak incidence of occurrence. D. These masses are typically described as smooth globoid and do not produce enlargement of the nerve. E. They are suspended eccentrically from the nerve root with a discrete attachment. ## Footnote The lesion represents a nerve root schwannoma. The majority of these arise from a dorsal nerve root. Ten to 15% extend through the dural root sleeve. The fourth through sixth decades represent the peak incidence of occur- rence. Schwannomas are typically described as smooth globoid and do not produce enlargement of the nerve but are suspended eccentrically from it with a discrete attachment.

Answer 316

A. Anaerobic B. Fast C. Stain dark with ATPase at pH 9.4 **D. Are found in red muscle** E. Have few mitochondria ## Footnote Type I fibers are characterized by slow contraction times and a high resistance to fatigue. Structurally, they have a small motor neuron and fiber diameter, a high mitochondrial and capillary density, and a high myoglobin content.

Answer 317

A. Pick bodies B. Lewy bodies **C. Cowdry type B bodies** D. Bunina bodies E. Lafora bodies ## Footnote Cowdry type A inclusions are intranuclear and are seen with cytomegalovi- rus, herpes, and subacute sclerosing panencephalitis (SSPE). Cowdry type B inclusions are intranuclear and are seen in acute poliovirus. The others listed are intracytoplasmic inclusions. Lafora bodies are seen in myoclonic epilep- sy. Bunina bodies are seen in amyotrophic lateral sclerosis (ALS).

Answer 318

A. Lateral spinothalamic B. Ventral spinocerebellar C. Ventral corticospinal **D. Dorsal spinocerebellar** E. Ventral spinothalamic ## Footnote The dorsal spinocerebellar is an uncrossed tract.

Answer 319

A. Nystagmus is horizontal and ipsilateral to the aff ected side. B. Nystagmus is vertical. C. Falling and past-pointing are contralateral. **D. Nystagmus is contralateral to the aff ected side.** E. None of the above ## Footnote Nystagmus in Ménière’s disease is horizontal and contralateral to the affect- ed side. Past-pointing and falling occur toward the affected side.

Answer 320

**A. Pulvinar** B. Anterior nucleus C. Centromedian nucleus D. VA nucleus E. VL nucleus ## Footnote The pulvinar has reciprocal connections with the inferior parietal lobule.

Answer 321

A. anterior commissure. B. hippocampal commissure. C. body of the corpus callosum. D. genu of the corpus callosum. **E. splenium of the corpus callosum.**

Answer 322

A. anterosuperiorly. **B. posterosuperiorly.** C. anteroinferiorly. D. posteroinferiorly. E. None of the above ## Footnote Pineal tumors usually lie between the precentral cerebellar vein and the vein of Galen. The precentral cerebellar vein is usually displaced posterosuperior- ly. This vein may be sacrificed if necessary.

Answer 323

A. Occipital condyle B. Inion **C. Pharyngeal tubercle** D. Pituitary gland E. Sphenoid sinus ## Footnote The pharyngeal tubercle is found in line with the vomer and foramen mag- num at the cranial base.

Answer 324

A. Posterior inferior cerebellar artery B. Posterior cerebral artery C. Anterior choroidal artery **D. All of the above** E. None of the above ## Footnote The anterior choroidal and lateral posterior choroidal supply the lateral ven- tricle. The medial posterior choroidal supplies the choroid plexus of the third ventricle. The posterior inferior cerebellar artery (PICA) supplies the choroid plexus of the third ventricle.

Answer 325

A. Asterixis B. Slowing of the EEG waves C. Increased levels of ammonia D. Increased levels of GABA neurotransmitter **E. Decreased levels of glutamate** ## Footnote The liver damage causes the levels of ammonia to rise because it is not converted to urea; this may lead to increased production of GABA. Glutamate is not involved.

Answer 326

A. Serum ceruloplasmin is low. B. Urinary copper is increased. C. The gene locus is on chromosome 13. **D. Inheritance is autosomal dominant.** E. Early in the course of the disease, liver biopsy shows a high copper content. ## Footnote Wilson’s disease (hepatolenticular degeneration) is a familial metabolic dis- ease transmitted as an autosomal recessive trait. The abnormal gene has been assigned to the esterase D locus on chromosome 13.

Answer 327

A. They serve as guides for migrating granular cell neurons during development. **B. They have cell bodies located in the molecular layer of the cerebellar cortex.** C. They undergo reactive gliosis adjacent to infarcts. D. They extend long cytoplasmic processes through the molecular layer to the subpial surface. E. They are inconspicuous until stimulated by local damage. ## Footnote Bergmann glia have cell bodies located in the Purkinje layer of the cerebellar cortex.

Answer 328

A. The signs are frequently unilateral. B. It classically involves spinal roots inferior to L3. C. It may result in profound motor defects. D. It may result in urinary or fecal incontinence. **E. It usually results in a Babinski sign** ## Footnote This is a lower motor neuron lesion and Babinski’s sign would not be expected.

Answer 329

A. the kinetic labyrinth. B. the ampullae. **C. the static labyrinth.** D. the cochlear duct. E. None of the abov ## Footnote The static labyrinth consists of the utricle and saccule. The vestibule is a cen- tral cavity of the inner ear that contains the saccule and utricle.

Answer 330

A. VA B. VL C. VPL **D. VPM** E. None of the above ## Footnote The ventral posteromedial (VPM) nucleus receives taste input via the ipsilat- eral central tegmental tract. The VPM nucleus receives sensory input from the head and oral cavity.

Answer 331

**A. a lateral suboccipital retrosigmoid approach.** B. a combined subtemporal presigmoid approach. C. an infratentorial supracerebellar approach. D. a suboccipital transtentorial approach. E. a pterional approach ## Footnote The lateral suboccipital retrosigmoid approach is best used for lateral tento- rial notch meningiomas that extend infratentorially.

Answer 332

**A. 6 years.** B. 12 years. C. 18 years. D. 26 years. E. 30 years. ## Footnote Calcifications are likely to be abnormal if encountered in children younger than 6 years. The incidence of pineal calcification is at most 40% by the age of 18.

Answer 333

**A. Anterior longitudinal ligament** B. Posterior longitudinal ligament C. Alar ligament D. Transverse ligament E. None of the above ## Footnote The anterior longitudinal ligament attaches the dens to the anterior tubercle of the atlas. The transverse ligament of the atlas is posterior to the dens. The apical and alar ligaments attach the dens to the foramen magnum.

Answer 334

A. third ventricle. **B. fourth ventricle.** C. left lateral ventricle. D. right lateral ventricle. E. septum pellucidum. ## Footnote The most frequent site of subependymoma is the fourth ventricle (50–60% of cases), followed by the lateral ventricles (30–40%). Less common sites are the third ventricle and septum pellucidum.

Answer 335

A. the anterior commissure. B. the fornix. **C. the rostrum of the corpus callosum.** D. the mammillary body. E. None of the above ## Footnote The lamina terminalis fills the interval between the anterior commissure and the optic chiasm.

Answer 336

**A. both eyes being deviated to the right at rest.** B. both eyes being deviated to the left at rest. C. the right eye being “down-and-out.” D. the patient being unable to look upward. E. both eyes being deviated upward. ## Footnote Damage to the right frontal eye field (area 8) results in deviation of the eyes to the right.

Answer 337

A. oligodendroglioma. B. low-grade astrocytoma. C. pleomorphic xanthoastrocytoma. **D. choroid plexus papilloma.** E. schwannoma. ## Footnote Choroid plexus papillomas frequently display immunopositivity for tran- sthyretin (prealbumin) and S-100.

Answer 338

A. 7 mL/100 g/min. **B. 16 mL/100 g/min.** C. 30 mL/100 g/min. D. 35 mL/100 g/min. E. 45 mL/100 g/min. ## Footnote Between 15 and 20 mL/100 g/min cortical evoked responses are lost and the (EEG) becomes isoelectric, but the neurons remain viable and are described as “idling.” At about 30 mL/100 g/min, the patient loses consciousness.

Answer 339

A. It arises from the ipsilateral Deiter’s nucleus. B. It is located in the lateral pontine tegmentum. **C. It crosses the midline with MLF fi bers.** D. It facilitates extensor muscle tone in the antigravity muscles. E. It is found at all spinal cord levels ## Footnote The lateral vestibulospinal tract is an uncrossed tract.

Answer 340

A. Anterior nucleus B. Centromedian nucleus C. Pulvinar D. VA **E. Mediodorsal nucleus** ## Footnote Lesions of the mediodorsal nucleus are found in patients with the Korsakoff amnestic state.

Answer 341

A. III **B. IV** C. V D. VI E. VII ## Footnote The trochlear nerve should be identified before transecting the tentorium.

Answer 342

A. They are the most common parapineal neoplasm. B. They occur predominantly in males. **C. They commonly occur at around age 30 and above.** D. They are fi ve to ten times more likely in Japan. E. They are infi ltrated by T cell lymphocytes ## Footnote Germinomas commonly occur in males in the first 3 decades.

Answer 343

A. It is sensitive to steroids. B. It may mimic multiple sclerosis. C. It can involve cranial nerves. **D. It is characterized pathologically by caseating granulomas.** E. Leptomeningeal involvement is common ## Footnote Pathologically central nervous system (CNS) sarcoid is characterized by non- caseating granulomas.

Answer 344

**A. Choroid plexus tumor** B. Gliosarcoma C. Cystic astrocytoma D. Oligodendroglioma E. Glioblastoma multiforme ## Footnote Although other tumors may be more common after 1 year of life, choroid plexus tumors are the most common tumor in the first year of life.

Answer 345

A. Frontal lobe **B. Temporal lobe** C. Parietal lobe D. Occipital lobe E. Basal ganglia ## Footnote A “square” ACA shift is usually caused by a holotemporal mass.

Answer 346

A. upper midbrain. B. lower midbrain. C. upper pons. **D. middle pons.** E. lower pons.

Answer 347

**A. Obex** B. Subcommissural organ C. Median eminence D. Organum vasculosum of the lamina terminalis E. Area postrema ## Footnote The obex is the caudal apex of the rhomboid fossa and marks the beginning of the “open medulla.”

Answer 348

A. Pericallosal **B. Anterior communicating** C. Posterior communicating D. Middle cerebral E. Superior hypophyseal ## Footnote Hyponatremia (Na < 130) can occur in up to 30% of ruptured anterior com- municating artery aneurysms due to the local proximity of key perforators that supply the anterior hypothalamic nuclei.

Answer 349

A. It is a branch of the vertebral artery. B. It supplies the vestibular nuclei in the medulla. **C. It supplies the medial lemniscus in the medulla.** D. It supplies the inferior cerebellar peduncle. E. It supplies the lateral spinothalamic tract.

Answer 350

A. is located lateral to the fovea. B. contains myelinated axons from the retinal ganglion cell layer of the retina. C. contains only cones. D. All of the above **E. None of the above** ## Footnote The optic disc (optic papilla) is located 3.5 mm nasal to the fovea centralis. It contains unmyelinated axons from the ganglion cell layer of the retina. The optic disc is the blind spot (contains neither rods nor cones).

Answer 351

A. Rectus capitis posterior major B. Superior obliquus capitis **C. Inferior obliquus capitis** D. Longissimus capitis E. None of the above ## Footnote The inferior obliquus capitis muscle forms a common border of the superior and inferior suboccipital triangles. The lateral borders of both triangles meet at the transverse process of the atlas, which is located 1 cm below the mas- toid tip.

Answer 352

A. the trigeminal nerve. B. the abducens nerve. **C. the facial nerve**. D. All of the above E. None of the above ## Footnote The facial nerve needs to be identified medially close to the brain stem and followed laterally.

Answer 353

A. The great majority of spinal meningiomas occur in females. B. The most common presenting symptom is pain. **C. Plain film calcification is often seen.** D. Inversion recovery sequences and use of gadolinium increase detection sensitivity. E. Calcospheres may be seen. ## Footnote Plain film calcification is rarely seen. Calcospheres are also known as psam- moma bodies.

Answer 354

A. Teres minor B. Teres major C. Latissimus dorsi D. Subscapularis **E. Infraspinatus** ## Footnote The infraspinatus is innervated by the suprascapular nerve, which originates from the upper trunk of the brachial plexus. The subscapularis is innervated by the upper and lower subscapular nerves. The teres major is innervated by the lower subscapular nerve. The latissimus dorsi is innervated by the thora- codorsal nerve. The teres minor is innervated by the axillary nerve.

Answer 355

A. Time of development is directly related to the rate of turnover of the cells. B. Cell loss after radiation occurs in connection with the cell division. **C. Time of development is directly dependent on the radiation dose.** D. Slowly proliferating tissue like CNS may take years to show the eff ects. E. All of the above statements are true ## Footnote The time of development of effects of radiation is dose independent.

Answer 356

A. Leigh’s disease B. MERFF C. MELAS D. Kearns–Sayre’s syndrome **E. Kawasaki’s disease** ## Footnote Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many of the body’s systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). MERRF stands for “myoclonic epilepsy with ragged-red fibers.” Kawasaki disease is a condition that causes inflammation in the walls of medium-sized arteries throughout the body, including the coronary arteries, which supply blood to the heart muscle. Kawasaki disease is also called mucocutaneous lymph node syndrome because it also affects lymph nodes, skin, and the mucous mem- branes inside the mouth, nose and throat. The etiology of Kawasaki disease is unknown. Most of the epidemiologic and immunologic evidence indicates that the causative agent is probably infectious. However, autoimmune reac- tions and genetic predisposition are suggested as possible etiologic factors.

Answer 357

A. Loss of heterozygosity (LOH) at 1p and 19q in oligodendrogliomas B. LOH at 22 in ependymomas C. LOH at 17 in astrocytomas D. Monosomy of 22 in ATRT **E. Amplification of N-myc in glioblastoma** ## Footnote Amplification of epidermal growth factor (EGF) occurs in glioblastoma. Dou- ble minutes (cytogenetic evidence of gene amplification) of N-myc occurs in medulloblastoma.

Answer 358

**A. myocardial infarction within the last 6 months.** B. age greater than 75. C. more than fi ve ventricular ectopic beats per minute. D. smoking more than one pack of cigarettes a day. E. being hepatitis C positive ## Footnote The Goldman cardiac risk score for noncardiac surgery indicates that a recent myocardial infarction (MI) is a contraindication to elective surgery.

Answer 359

A. Dorsal spinocerebellar B. Cuneocerebellar **C. Fastigiovestibular** D. Olivocerebellar E. Vestibulocerebellar ## Footnote The fastigiovestibular tract is an efferent pathway that passes through the superior cerebellar peduncle (SCP) (uncinate fasciculus of the SCP). The jux- tarestiform body is a component of the inferior cerebellar peduncle and con- tains afferent (vestibulocerebellar) and efferent (cerebellovestibular) fibers.

Answer 360

A. unilateral destruction of the cuneus. **B. bilateral destruction of both cunei.** C. unilateral destruction of the lingual gyrus. D. bilateral destruction of both lingual gyri. E. None of the above ## Footnote Bilateral destruction of both cunei results in a lower altitudinal hemianopia.

Answer 361

A. Temporary clipping of the carotid in the neck B. Lumbar drainage C. Preoperative use of steroids D. Keeping the patient intubated until surgery **E. Minimal retraction** ## Footnote A posterior communicating artery aneurysm is prone to rupture with retration on the temporal lobe.

Answer 362

A. It is an indication of the activity peripheral to the tumor. **B. It is easier to detect than the other waves.** C. Wave 5 is an accurate predictor of hearing postoperatively regardless of N1. D. All of the above E. None of the above ## Footnote Wave 5 is an indication of auditory nerve activity central to the tumor. It is easier to detect than the other waves. Wave 5 is generated in the brainstem. When used with N1 (monitors action potential of the auditory nerve), it is useful for predicting postoperative hearing function.

Answer 363

A. Axons are intact. B. Unidentifi ed bright objects (UBOs) may be seen on MRI. C. Active lesions show contrast enhancement. **D. Initial symptoms are referable to motor function.** E. About 10 percent have a positive family history. ## Footnote The most common symptom at initial presentation is referable to sensation.

Answer 364

A. Anterior thalamus B. Cingulated gyrus C. Fornix D. Hippocampus **E. Dorsomedial thalamus** ## Footnote The dorsomedial thalamus is a part of the basolateral circuit. The basolateral circuit passes from the orbitofrontal cortex to the anterior temporal cortex via the uncinate fasciculus, then to the amygdala and the dorsomedial nucle- us of the thalamus, and back to the orbitofrontal cortex via a thalamofrontal radiation. The circuit of Papez passes from the septal region via the cingulat- ed bundle to the hippocampus, then via the fornix to the mammillary bodies via the mammillothalamic tract to the anterior thalamus, then from the an- terior thalamus back to the cingulum.

Answer 365

**A. White matter degeneration aff ecting mostly subcortical U-fi bers** B. Bilateral spongiform degeneration of the thalamus and basal ganglia C. Degeneration of the peripheral nerves D. Degeneration of the spinal cord E. Degeneration of the brainstem ## Footnote White matter degeneration of the subcortical U-fibers. This is a feature of Canavan’s disease, which is a different metabolic disease with the same in- heritance pattern and is caused by a deficiency of the enzyme N-acetyl-as- partoacylase.

Answer 366

A. Brodmann area 40. B. Brodmann area 41. C. Brodmann area 42. D. Brodmann area 43. **E. Brodmann area 44.** ## Footnote Broca’s aphasia results from damage to Brodmann area 44 (inferior frontal gyrus). The most common cause of expressive aphasia is stroke. The most effective pharmacological treatments are piracetam and amphetamine.

Answer 367

A. adrenoleukodystrophy. **B. Canavan’s disease.** C. Alexander’s disease. D. Krabbe’s disease. E. metachromatic leukodystrophy ## Footnote Canavan’s disease is associated with a point mutation of aspartoacylase 2 leading to elevated levels of N-acetylaspartic acid (NAA). It is a progres- sive, fatal neurological disorder that is caused by this mutation, which affects myelin.

Answer 368

A. hemophilia A. B. factor V defi ciency. **C. aspirin.** D. heparin. E. vitamin K defi ciency ## Footnote Antiplatelet drugs are the most common cause of platelet disorders leading to excessive bleeding at surgery. Excessive bleeding in surgery can usually be seen early at skin incision and during initial dissection. If the surgeon believes that the unexpected excessive bleeding will pose a risk to the patient, it is ad- visable to abort the procedure, obtain a hematology consult, and proceed with surgery on another day. If the surgeon decides that the bleeding is not going to pose a threat to the patient, it is advisable to leave a small drain under only light bulb suction (not fully compressed suction), to use a pressure dressing at the end of the case, and to obtain a hematocrit after the case.

Answer 369

**A. Poxvirus** B. Picornavirus C. Paramyxovirus D. Reovirus E. Rhabdovirus ## Footnote Poxvirus is a DNA virus. Viral meningitis occurs in up to 50% of paramyx- ovirus infections (mumps). Rabies (rhabdovirus) targets the limbic tissue. DNA viruses cause SSPE, PML (papovavirus), and herpes encephalitis. RNA viruses are implicated in meningitis, AIDS, Ebola, severe acute respiratory syndrome (SARS), West Nile, and polio. Herpes simplex encephalitis (HSE) is the only CNS viral infection whose course and outcome are improved by specific antiviral therapy (acyclovir). HSE can lie dormant in the ganglion of the trigeminal nerve causing trigeminal neuralgia. If acyclovir is not helpful, radiosurgical treatment of the trigeminal nerve may be indicated.

Answer 370

A. radiotherapy. B. chemotherapy. C. gene therapy. **D. photochemotherapy.** E. None of the above ## Footnote Hematoporphyrin derivative is an agent that is capable of photosensitizing malignant tumor cells. Other photosensitizers include rhodamine, acridine orange, phthalocyanines, and pyrilium derivatives.

Answer 371

A. I. **B. II.** C. III. D. IV. E. V ## Footnote The cranial nerve most sensitive to radiation is the optic nerve and the chi- asm, with a single fraction dose tolerance of 8 Gy. Other cranial nerves can be affected from radiation in order of frequency: XII, XI, X, V, and VI. The recurrent laryngeal nerve can be injured after radiation therapy for breast or lung cancers; therefore, in anterior cervical discectomy and fusion (ACDF) cases, patients with a history of radiation in these areas should be briefed on the higher risk of hoarseness and vocal changes after surgery.

Answer 372

**A. the junction of the transverse and sigmoid sinuses.** B. the jugular bulb. C. AICA. D. All of the above E. None of the above ## Footnote The junction of the transverse and sigmoid sinuses is usually located 1–1.5 cm rostral to the mastoid emissary vein. In this photograph (reprinted with permis- sion from The American Society of Neuroradiology) the mastoid emissary vein is labeled n, the transverse sinus is labeled b, and the sigmoid sinus is labeled c. Profuse bleeding can be seen in dissections near this vein as well as other veins in the cerebellar area. It is important for the surgeon to have hemoclips, hemo- static packing agents, and BioGlue (CryoLife)/DuraSeal (Optimus Medical) ready in the room should the need arise in any posterior fossa surgery.

Answer 373

A. the substantia gelatinosa. **B. the nucleus proprius.** C. the zona intermedia. D. All of the above E. None of the above ## Footnote The Rexed laminae is the system of ten layers of gray matter (I–X) named after Swedish neuroscientist Bror Rexed in the 1950s. (Figure from THIEME Atlas of Anatomy, Head and Neuroanatomy, © Thieme 2007, Illustration by Markus Voll.)

Answer 374

A. Mossy fi bers terminal B. Golgi cell dendrite C. Granule cell dendrite **D. Purkinje cell** E. Golgi cell axon termina ## Footnote Cerebellar glomeruli are small, intertwined nerve fiber terminals in the granular layer of the cerebellar cortex. Glomeruli contain synaptic connec- tions that contain axons of incoming mossy fibers, axons and dendrites of Golgi type II cells, and dendrites of granule cells. Purkinje cells are not part of the glomerulus. The cerebellar glomeruli are the first stop for afferent nerve fibers entering the cerebellum.

Answer 375

A. cellular apoptosis. B. endothelial cell proliferation. C. demyelination of the nerve fi bers. D. diff use vasculitis. **E. focal white matter necrosis.** ## Footnote Focal white matter necrosis is the most common histological evidence of late radiation-related CNS injury.

Answer 376

A. Cervical B. Thoracic C. Lumbar **D. Sacral** E. None of the above ## Footnote Sacral. The gray matter changes shape throughout the spinal cord depending on the neural requirements of a given region.

Answer 377

A. MERRF **B. CADASIL** C. MPS IV D. HHT E. VHL ## Footnote Cerebral autosomal dominant arteriopathy with subcortical infarcts (CA- DASIL) leads to subcortical ischemic damage, myelin loss, lacunar infarcts, and gliosis. Ischemic strokes are the most frequent presentation of CADASIL where the underlying pathology is progressive degeneration of the smooth muscles cells in blood vessels.

Answer 378

A. hyperglycemia. B. psychosis. **C. exacerbation of peptic ulcer.** D. aseptic necrosis. E. skin rash. ## Footnote Exacerbation of peptic ulcer is the most common side effect of high-dose dexamethasone. A short course (e.g., ≤ 4 days) of steroids does not need to be tapered. Longer courses of steroids should be tapered gradually.

Answer 379

**A. Patients rarely complain of headache.** B. Nausea, vomiting, mental status changes, and cranial nerve palsies are features. C. It is caused by an encapsulated budding yeast. D. In some communities, it is more common than toxoplasmosis as a cause of presenting neurological illness associated with HIV infection. E. Infection occurs by the inhalation of organisms resulting in a primary pulmonary focus of infection ## Footnote Headache is almost universally noted in patients with cryptococcal menin- gitis. Poor prognosis of cryptococcal meningitis is seen with positive India ink stain, low CSF leukocyte count, a positive blood culture, presence of C. neoformans at extraneural sites, high CSF cryptococcal antigen titers, CSF hypoglycorrhachia, and an increased CSF opening pressure. Pharmacological treatment involves amphotericin B plus flucytosine.

Answer 380

A. 1% B. 15% C. 45% D. 65% **E. 85%** ## Footnote Since over 85% of cerebrospinal fluid leaks from basilar skull fractures will resolve spontaneously, the primary approach is expectant observation. Prophylactic antibiotics have not been shown to decrease the risk of menin- gitis and are not recommended. CSF diversion with lumboperitoneal shunts may be used for refractory cases.

Answer 381

A. PRL. B. ACTH. **C. TSH.** D. All of the above E. None of the above ## Footnote Pituitary tumors that secrete thyroid-stimulating hormone (TSH) also fre- quently co-secrete the glycoprotein hormone alpha-subunit. An alpha-sub- unit:TSH ratio of > 1 favors the diagnosis of TSH-secreting adenoma. TSH is a glycoprotein and consists of two subunits, alpha and beta. The alpha sub- unit is identical to that of human chorionic gonadotropin (hCG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). The beta subunit is unique to TSH and determines its receptor specificity.

Answer 382

**A. the superior semicircular canal.** B. the lateral semicircular canal. C. the posterior semicircular canal. D. All of the above E. None of the above ## Footnote The superior (anterior) semicircular canal is identified by the arcuate emi- nence at the base of the skull.

Answer 383

A. the sphenoid bone only. B. the sphenoid and ethmoid bones. C. the zygomatic and palatine bones. **D. the sphenoid and maxilla.** E. None of the above ## Footnote The inferior orbital fissure is formed by the orbital surface of the greater wing of the sphenoid and the orbital surface of the maxilla. The inferior division of the ophthalmic vein passes through the inferior orbital fissure.

Answer 384

**A. the medial vermal region of the anterior lobe.** B. the lateral region of anterior lobe. C. the medial vermal region of posterior lobe. D. the lateral region of posterior lobe. E. None of the above ## Footnote Many spinocerebellar fibers are distributed to the medial vermal region of the anterior lobe of the cerebellum.

Answer 385

A. Cerebral arteriovenous malformation B. Metastatic tumor from non–small cell lung carcinoma C. 1 cm acoustic schwannoma limited to the IAC D. 1.5 cm petrous apex meningioma not distorting the brainstem **E. 1 cm aneurysm at the top of basilar artery** ## Footnote Aneurysms are not indications for radiosurgery. The prevalence of intracra- nial aneurysm is about 1–5% so observation may be indicated in the majority of healthy patients where small aneurysms are found incidentally.

Answer 386

A. Initial symptoms present between ages 20–40 years. B. It may cause longstanding ventriculitis. **C. It is associated with midline fusion defect.** D. It is characterized by linear growth. E. Spillage of tumor contents in the subarachnoid space must be avoided. ## Footnote The lesion is an epidermoid of the cerebellopontine angle. Epidermoid usu- ally presents in the 20- to 40-year age group. Unlike dermoids, they are not associated with midline defect. Spilling of their contents may cause a chem- ical meningitis or ventriculitis; therefore spillage of tumor contents in the subarachnoid space must be avoided. The main goal of therapy is complete excision of the tumor wall and contents to prevent recurrences. Radiation or chemotherapy has no role in the management. Steroids have been shown to be effective in preventing the inflammatory response and possible ventricu- litis associated with these tumors.

Answer 387

A. Maple syrup urine disease **B. Adrenoleukodystrophy** C. Wilson’s disease D. Refsum’s disease E. Homocystinuria ## Footnote Adrenoleukodystrophy displays X-linked recessive inheritance. Maple syr- up urine disease is an autosomal recessive metabolic disorder affecting branched-chain amino acids. Adrenoleukodystrophy is a disorder of peroxi- somal fatty acid beta oxidation, which results in accumulation of very-long- chain fatty acids. Wilson’s disease is an autosomal recessive disorder where there is an alteration of the ATP7B gene resulting in inability to excrete cop- per from the body. Refsum’s disease is an autosomal recessive neurological disease that results from overaccumulation of phytanic acid in cells and tis- sues. Homocystinuria is an inherited disorder of the metabolism of the ami- no acid methionine.

Answer 388

A. hypervolemic and hypernatremic. B. hypervolemic and hyponatremic. C. hypovolemic and hypernatremic. **D. hypovolemic and hyponatremic.** E. None of the above ## Footnote In cerebral salt wasting syndrome (CSWS), there is inappropriate natriure- sis and diuresis. CSWS is an endocrine condition of low sodium and dehy- dration in response to trauma, intracranial hematoma, or the presence of brain tumors.

Answer 389

A. It is the most common cause of intracerebral mass associated with HIV infection when CD4 counts fall below 100/mm3. B. Chorea in a patient with AIDS may be pathognomonic of toxoplasmosis. C. Radiographic images show an asymmetric target sign. **D. The presenting neurological symptom is nonfocal and superimposed on a global encephalopathy.** E. Therapy includes pyrimethamine and sulfadiazine. ## Footnote The presenting neurological symptoms and signs in HIV-infected individuals with Toxoplasma encephalitis are focal in nature. Hemiparesis is the most common focal finding.

Answer 390

A. frontal bone. B. sphenoid bone. C. temporal bone. **D. parietal bone.** E. occipital bone. ## Footnote The fracture that initiates the leptomeningeal cyst may not be clinically evi- dent but most commonly involves the parietal bone. A growing fracture can occur anywhere, including the skull base. Skull radiographs and CT scans are useful at initial injury and at follow-up.

Answer 391

A. Bromocriptine B. GnRH agonists **C. Octreotide** D. All of the above E. None of the above ## Footnote Octreotide is fairly well tolerated; however, gallstone formation can de- velop in 10–20% of patients and is related to the inhibitory effect of oc- treotide on gallbladder motility. Other adverse effects of octreotide are headache, hypothyroidism, cardiac conduction abnormalities, and gastro- intestinal reactions.

Answer 392

A. The patient is elderly with a medium-sized tumor. B. The patient has recently been hospitalized and is on two “heart medications” and a “water pill.” C. The tumor is on the side of the patient’s only hearing ear. **D. All of the above** E. None of the above ## Footnote Stereotactic radiosurgery is becoming the standard of care for acoustic neu- romas. The need for a tissue biopsy (which adds additional risk) is becom- ing less important in these tumors because radiological features are usually all that is needed to start treatment. In the event that one is mistaken and a meningioma is truly in the cerebellopontine (CP) angle, the radiosurgical dosage is essentially the same. Tissue diagnoses are especially dangerous in intramedullary spinal cord tumors where the patient is neurologically intact. Empirical radiosurgery performed on spinal cord tumors is being reported to have good results.

Answer 393

**A. the facial and superior vestibular nerves.** B. the facial and inferior vestibular nerves. C. the acoustic and superior vestibular nerves. D. the acoustic and inferior vestibular nerves. E. None of the above ## Footnote Bill’s bar is named after William Fouts House (1923–2012), an American otologist referred to as Dr. Bill. This landmark divides the superior compart- ment of the internal acoustic meatus into an anterior and posterior compart- ment. Anterior to Bill’s bar, in the anterior superior quadrant, are the facial nerve and nervus intermedius, and posterior to it in the posterior superior quadrant is the superior division of the vestibular nerve.

Answer 394

A. Trigeminal artery B. Otic artery C. Hypoglossal artery D. Proatlantal intersegmental artery **E. Posterior communicating artery** ## Footnote The fetal posterior communicating (Pcom) artery is the most frequent of the persistent fetal circulations. PCom aneurysms are one of the most common aneurysms, accounting for 25% of intracranial aneurysms. These aneurysms are often associated with large or fetal PCom arteries, and the treatment of these aneurysms requires significant diligence in order to maintain flow in the PCom artery.

Answer 395

A. Audiogram with pure tones and speech reception B. Counseling regarding the options of surgery or radiosurgery C. Workup for a planned craniotomy **D. Consent for angiography and possible embolization** E. Observation ## Footnote An acoustic neuroma is shown in the radiograph and angiography has no role in the management of acoustic tumor.

Answer 396

A. ipsilateral parietal lobe. B. contralateral parietal lobe. C. ipsilateral temporal lobe. **D. contralateral temporal lobe.** E. occipital cortex ## Footnote Interruption of Meyer’s loop fibers in the temporal lobe results in the “pie in the sky” lesion.

Answer 397

A. Fragile X syndrome B. Myotonic dystrophy **C. Olivopontocerebellar atrophy** D. Huntington’s disease E. Machado–Joseph’s disease ## Footnote CAG is a common trinucleotide repeat and is translated into a series of unin- terrupted glutamine residues forming a polyglutamine tract.

Answer 398

A. chest tightening. B. lightheadedness. **C. tingling around the mouth.** D. shortness of breath. E. focal seizures.

Answer 399

**A. There is progressive attenuation of the cerebellar and premotor areas, but no change of activity in the primary motor cortex.** B. There is progressive attenuation of the cerebellar, but no change in the premotor and primary motor cortices. C. There is no change in the cerebellar, but progressive attenuation of the premotor and primary motor cortices. D. There is no change in the cerebellar and premotor cortices, but progressive attenuation of the primary motor cortex. E. There is no change in activity of the cerebellar, premotor, or primary motor cortex ## Footnote If a motor task is performed repeatedly to mastery, there is progressive atten- uation of the cerebellar and premotor areas, with no change of activity of the primary motor cortex. This can be verified with fMRI scanning.

Answer 400

A. They can appear crescentic. **B. The lucid interval is seen in ~ 80% of patients.** C. A dry eye postoperatively can occur from traction injury of a nerve. D. Outcome correlates well with the clinical state prior to surgery. E. Outcome is inversely correlated with delay in surgery. ## Footnote The classic lucid interval is seen in only one-third of patients. Traction on the greater superficial petrosal nerve may occur with traction on the floor of the middle fossa, which may result in a dry eye postoperatively. Tacking sutures at surgery may be used for tenting of the dura during healing; however, a small, round JP drain with small holes under bulb suction for a couple days can work just as well, especially in a young patient.

Answer 401

A. tumor extension into the middle fossae. B. a dumbbell shape with constriction in the middle of the tumor. C. a tumor claimed to be fi brous on previous transsphenoidal resection. **D. All of the above** E. None of the above ## Footnote All are indications for craniotomy. Pituitary tumors can be effectively debulked with their remnant treated with radiosurgery several months later.

Answer 402

A. third ventricle. B. jugular vein. **C. lateral recess of the fourth ventricle.** D. lumbar cistern. E. cisterna magna. ## Footnote An ABI (auditory brainstem implant) is designed to stimulate auditory neu- rons of the cochlear nucleus and is placed in the lateral recess of the fourth ventricle at the time of acoustic tumor removal.

Answer 403

**A. Root** B. Trunk C. Division D. Cord E. Branch ## Footnote The dorsal scapular nerve arises from the brachial plexus, usually from the plexus root of C5. This nerve leaves C5 and commonly pierces the middle sca- lene muscle and continues deep to the levator scapulae and the rhomboids.

Answer 404

A. Alzheimer’s disease B. Down’s syndrome C. Progressive supranuclear palsy D. SSPE **E. All of the above** ## Footnote All are associated with neurofibrillary tangles. Neurofibrillary tangles are the results of defective assembly of microtubules and/or neurofilaments. These tangles are aggregates of hyperphosphorylated tau proteins.

Answer 405

A. The temporal tip B. The area lateral to cranial nerve I C. The right-sided inferior frontal gyrus D. All of the above **E. None of the above** ## Footnote The gyrus rectus may be removed (medial to olfactory nerve) in order to gain better visualization before clipping of an anterior communicating artery aneurysm.

Answer 406

A. anterior clinoid process. B. oculomotor nerve. **C. optic strut.** D. trochlear nerve. E. vomer. ## Footnote At the optic strut, the ophthalmic artery pierces the dura to enter the orbit. After the origin of the ophthalmic artery, the ICA passes the tip of the anteri- or clinoid process.

Answer 407

A. Sulcus cinguli and parieto-occipital sulcus B. Calcarine and cingulate C. Sylvian and calcarine **D. Parieto-occipital and calcarine** E. None of the above ## Footnote Cuneus is Latin for wedge. The cuneus corresponds to Brodmann area 17 and is a smaller lobe in the occipital lobe of the brain. It is involved in basic visual processing.

Answer 408

A. Oxyhemoglobin and bilirubin are the agents likely producing the meningeal response. **B. The size of an intracerebral hematoma is directly related to the chance of the patient developing vasospasm.** C. Only ~ 1% of cerebral aneurysms result in subdural bleeding. D. A cerebral aneurysm has a single layer of endothelium. E. The most important factor in assessing bleeding risk is the temporal relationship to the previous bleed. ## Footnote The size of the hematoma is inversely related to the chance of the patient developing vasospasm. This reflects the fact that most of the blood has gone into the brain rather than the subarachnoid space.

Answer 409

**A. reduce cerebral metabolic rate (CMR) and increase cerebral blood flow (CBF).** B. reduce CMR and CBF. C. increase CMR and CBF. D. increase CMR and reduce CBF. E. have no eff ect on CMR and increase CBF. ## Footnote Volatile anesthetics produce a dose-related reduction in CMR and a simultane- ous increase in CBF. Intravenous anesthetic agents (except ketamine) decrease CMR and CBF in parallel. Volatile anesthetic agents increase CSF production.

Answer 410

A. upper trunk. B. upper and middle trunk. C. middle trunk. D. roots of C5 and C6. **E. lower trunk** ## Footnote Note that the median sensory response, mediated by upper trunk fibers, would remain normal in lower trunk plexopathy. Trauma accounts for the majority of brachial plexus plexopathies. A lesion of the brachial plexus can result in motor, sensory, and sympathetic findings.

Answer 411

A. Horner’s syndrome. B. Frey’s syndrome. C. Chagas’s disease. **D. Familial dysautonomia.** E. Huntington’s disease ## Footnote An abnormal skin histamine response is a characteristic feature of patients with familial dysautonomia. Familial dysautonomia is also called Riley–Day syndrome and hereditary sensory and autonomic neuropathy type III. Famil- ial dysautonomia is seen almost exclusively in Ashkenazi Jews and is inherit- ed in an autosomal recessive fashion.

Answer 412

A. Foramen ovale B. Foramen magnum **C. Jugular foramen** D. All of the above E. None of the above ## Footnote The jugular foramen transmits a number of vital structures from the posteri- or fossa to the neck. This foramen is situated at the junction of the temporal and occipital bone. It is the site for glomus jugulare tumors, schwannomas, and meningiomas. Glomus tumors produce local bony destruction, whereas schwannomas produce a smooth-edged enlargement of the foramen.

Answer 413

A. Diagonal band of Broca **B. Fasciculus retroflexus** C. Ansa lenticularis D. Lenticular fasciculus E. Obex ## Footnote Acetylcholine and substance P are transmitters in this projection. The fas- ciculus retroflexus is also known as the habenulointerpeduncular tract. The habenula receives input from the brain via the stria medullaris thalami and outputs to many midbrain areas involved in releasing neurotransmitters such as dopamine, norepinephrine, and serotonin.

Answer 414

A. They form as part of normal aging but are not aff ected by hypertension. **B. They form as part of normal aging and are accentuated by hypertension.** C. They are not part of the normal aging process and are not aff ected by hypertension. D. They are not part of normal aging and are accentuated by hypertension. E. They usually aff ect blood vessels > 300 μm in diameter. ## Footnote Charcot–Bouchard aneurysms (also known as military aneurysms or microa- neurysms) are aneurysms of the brain vasculature that occur in small blood vessels < 300 μm diameter. They are most often located in the lenticulostriate vessels of the basal ganglia and are associated with chronic hypertension.

Answer 415

A. dizziness, ataxia, and balance problems. B. expressive aphasia with positive Rhomberg’s sign. C. tinnitus and reduced hearing in the right ear with frequent falling. **D. ptosis of the right eye with weakness of external ocular muscles.** E. weakness in the right side of body, especially in the upper limbs ## Footnote The lesion is a cavernous sinus meningioma. Lesions in this region that are approximately ≤ 3 cm are ideal for radiosurgery.

Answer 416

A. Superior cerebellar artery B. Basilar artery **C. AICA** D. PICA E. Vertebral artery ## Footnote The anterior inferior cerebellar artery loops around cranial nerves VII and VIII.

Answer 417

A. Olive B. Tuberculum cinereum C. Vagal trigone **D. Facial colliculus** E. Origin of the glossopharyngeal nerve ## Footnote The facial colliculus is located in the pontine half of the rhomboid fossa. The tuberculum cinereum (not to be confused with the tuber cinereum of the hypothalamus) is a surface eminence of the medulla that overlies the spinal trigeminal tract and nucleus.

Answer 418

A. Arteriovenous malformations can contain neural parenchyma. B. Calcifi cation is common in cavernous malformations. **C. Hemosiderin-laden macrophages are common in venous malformations.** D. Capillary malformations do not show progressive growth. E. Early angiographic fi lling is seen with AVMs ## Footnote Hemosiderin-laden macrophages are seen with cavernous malformation.

Answer 419

A. clear beneficialeff ect, improve angiographic vasospasm, and increase CBF. B. clear beneficialeff ect and improve angiographic vasospasm and functional outcome. **C. modest beneficial effect.** D. detrimental effect. E. detrimental effect and decrease CBF ## Footnote Calcium channel–blocking agents can be expected to have a beneficial effect in the patient; however, there is no lasting effect on angiographic vasospasm and no increase in CBF. The evidence for calcium channel blocking agents is not beyond all doubt, but given the potential benefits and modest risks of this treatment, it is indicated in patients with aneurysmal SAH.

Answer 420

A. the plexal point, tonsillomedullary segment. B. the choroidal point, tonsillomedullary segment. C. the plexal point, telovelotonsillar segment. **D. the choroidal point, telovelotonsillar segment.** E. None of the above ## Footnote The top of the cranial loop is the choroidal point, located in the teloveloton- sillar segment of the PICA. The plexal point is the point where the anterior choroidal artery enters the choroidal fissure.

Answer 421

A. the anterior right hemisphere. **B. the posterior right hemisphere.** C. the anterior left hemisphere. D. the posterior left hemisphere. E. None of the above ## Footnote The principal anatomical substrate of perceptual organization is the posteri- or right hemisphere. Posterior right hemisphere lesions tend to produce the most severe deficits of constructional praxis.

Answer 422

**A. Trautmann’s triangle**. B. Parkinson’s triangle. C. Wernicke’s triangle. D. Labbé’s triangle. E. Calot’s triangle. ## Footnote Trautman’s triangle is a space bounded by bony labyrinth anteriorly, sigmoid sinus posteriorly, and dura containing superior petrosal sinus superiorly. This area is a route where infections of temporal bone may traverse and af- fect the cerebellum.

Answer 423

A. the trapezoid body. **B. the commissure of Probst.** C. the juxtarestiform body. D. All of the above E. None of the above ## Footnote The lateral lemniscus is a tract of axons in the brainstem that carries infor- mation about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain.

Answer 424

A. choroid plexus tumor. B. colloid cyst. C. central neurocytoma. **D. chordoid glioma.** E. glioblastoma multiforme. ## Footnote These tumors are rare, but they must enter into the differential diagnosis of a solid third ventricle enhancing mass that is glial fibrillary acidic protein (GFAP) positive.

Answer 425

A. Three tumors, each measuring 1–1.5 cm within the right hemisphere B. A solitary left parietal tumor measuring 2cm × 2cm × 1.8cm **C. A 2.5 cm left mesial temporal tumor with clinical signs of herniation** D. Tumors in both the supratentorial and the infratentorial compartment E. No tissue biopsy from the brain ## Footnote Impending herniation regardless of the tumor size or number is an indica- tion for open surgery. One can proceed empirically with cranial radiosurgery without tissue biopsy with good results. A short course of steroids after ra- diosurgery is indicated for swelling prophylaxis.

Answer 426

A. outer aspect of the lesser wing of the sphenoid. **B. inner aspect of the lesser wing of the sphenoid.** C. outer aspect of the greater wing of the sphenoid. D. inner aspect of the greater wing of the sphenoid. E. cavernous sinus. ## Footnote The sphenoparietal sinus runs along the ridge of the sphenoid lesser wing and collects tributaries of the sylvian veins to empty into the cavernous sinus.

Answer 427

A. on the lateral aspect of the frontal lobe. B. on the medial aspect of the frontal lobe. C. on the lateral aspect of the occipital lobe. D. on the medial aspect of the occipital lobe. **E. on the medial aspect of the parietal lobe** ## Footnote The precuneus is bounded posteriorly by the parieto-occipital sulcus. This area is involved with self-consciousness, memory, and visual-spatial processing.

Answer 428

A. capillary telangiectasia. **B. venous malformation**. C. arteriovenous malformation. D. cavernous malformation. E. dural arteriovenous fi stula ## Footnote Venous malformations may occur in up to 2% of individuals. Venous vascular malformations are also known as venous angiomas. A newer term, develop- mental venous anomalies (DVA), has been recommended as a more appropri- ate term.

Answer 429

**A. ophthalmic artery.** B. maxillary artery. C. middle meningeal artery. D. occipital artery. E. facial artery. ## Footnote The anterior meningeal artery is also known as the anterior falx artery. This artery can be enlarged in frontal tumors, falcine meningiomas, and moyamoya disease.

Answer 430

A. the middle cerebral artery. B. the internal cerebral artery. **C. the recurrent artery of Heubner.** D. the posterior communicating artery. E. None of the above ## Footnote The recurrent artery of Heubner enters the anterior perforating substance and supplies the head of the caudate, anterior limb of the internal capsule, the anterior putamen and GP, the septal nuclei, and the inferior frontal lobe. Otto Heubner was a German pediatrician who made contributions in cere- brospinal meningitis, syphilitic endarteritis obliterans, aseptic practices in the hospital environment, and infectious disease.

Answer 431

A. type I, longitudinal B. type II, longitudinal **C. type I, circular** D. type II, circular E. None of the above ## Footnote The external sphincter is composed of circularly arranged striated muscle fibers that are mostly type I (slow twitch).

Answer 432

A. It should be suspected in a multitrauma victim with mandibular fractures and submental lacerations. B. Prevertebral soft tissue swelling may be the only clue to its diagnosis. C. The gap between the occipital condyles and condylar surface of the atlas is >5 mm. **D. The distance between the tip of the dens and the basion is > 12mm** E. The clivus line is not tangential to the odontoid. ## Footnote Harris’s method is the most clinically useful means of assessing atlanto-oc- cipital dislocation. The basion should lie within 12 mm of the superior con- tinuation of a line drawn along the posterior cortex of the body of the axis, and the distance of the basion and tip of the odontoid is normally < 12 mm.

Answer 433

A. dendrite. B. soma. **C. hillock.** D. node of Ranvier. E. axon terminal. ## Footnote There are many more sodium channels located at the axon hillock. Synaptic inputs are summated in the region of the action hillock and the action poten- tial is initiated here.

Answer 434

A. Pilocytic astrocytom **B. Ganglioglioma** C. DNET D. Astrocytoma E. Pleomorphic xanthoastrocytom ## Footnote Ganglioglioma is twice as common as dysembryoplastic neuroepithelial tu- mors (DNET) in causing temporal lobe epilepsy. Gangliogliomas occur mostly in children and young adults, and calcification is frequently present on imag- ing studies of these tumors.

Answer 435

A. Trigeminal neuralgia refractory to medication B. Glossopharyngeal neuralgia in a patient with carbamazepine hypersensitivity C. Unilateral essential tremors refractory to medication D. Parkinson’s tremor in the left upper extremity with levodopa-induced dyskinesias **E. Huntington’s chorea** ## Footnote Huntington’s chorea is not an indication for radiosurgery.

Answer 436

A. The entire insula drains to the deep venous system. B. The entire insula drains to the superfi cial venous system. C. The anterior portion of the insula drains to the deep system. D. The posterior portion of the insula drains to the superfi cial system. **E. None of the above** ## Footnote There is a tendency for the posterior insula to drain more frequently into the deep system, whereas the anterior portion of the insula drains to the super- ficial venous system.

Answer 437

A. Posterolateral fi ssure B. Horizontal fi ssure C. Dorsolateral fi ssure **D. Primary fi ssure** E. Postlunate fi ssure ## Footnote The primary fissure separates the anterior cerebellar lobe from the posterior cerebellar lobe. The horizontal fissure is located within the posterior lobe. The dorsolateral fissure is synonymous with the posterolateral fissure and separates the flocculonodular lobe from the posterior lobe.

Answer 438

A. Dural arteriovenous fi stulas are believed to be acquired. B. Normal neural parenchyma is seen within juvenile AVMs. C. Glomus AVMs may have associated aneurysms. D. Acute progression is most likely due to venous congestion. **E. Dural AV fi stulas have a female predilection** ## Footnote Dural arteriovenous (AV) fistulas have a male predominance, are acquired lesions, have low flow, rarely hemorrhage, and have a gradual onset of symptoms.

Answer 439

A. 1–8 mL/100 g/min. **B. 8–23 mL/100 g/min.** C. 23–30 mL/100 g/min. D. 30–40 mL/100 g/min. E. 40–50 mL/100 g/min ## Footnote Neurons in the penumbra (8–23 mL/100 g/min) survive but do not function. Below 8 mL/100 g/min neurons cannot recover. Hypothermia can allow a modestly prolonged survival at these blood flows.

Answer 440

A. Substantia nigra B. Pedunculopontine nucleus **C. Zona incerta** D. Subthalamic nucleus E. None of the above ## Footnote The zona incerta is the gray matter between the thalamic and lenticular fas- ciculi. Laterally, the zona incerta is continuous with the thalamic reticular nucleus.

Answer 441

A. Medial parts of the frontal lobes B. Preoptic region of the hypothalamus C. Basal ganglia **D. All of the above** E. None of the above ## Footnote Evidence for these areas influencing micturition comes from positron emis- sion tomographic scanning.

Answer 442

A. Lateral, inferior B. Lateral, superior **C. Medial, inferior** D. Medial, superior E. None of the above ## Footnote The juxtarestiform body carries both afferent and efferent fibers connecting the vestibular nuclei and the flocculonodular lobe and fastigial nucleus of the cerebellum. It coordinates balance and eye movements by communication between the vestibular apparatus and the cerebellum.

Answer 443

A. IA B. IB **C. II** D. III E. IV ## Footnote Type II fibers connect to nuclear chain fibers and static nuclear bag fibers. These connections are flower-spray endings and insert into the ends of the fiber.

Answer 444

A. Ventral spinocerebellar tract **B. Dorsal spinocerebellar tract** C. Gracile fasciculus D. Cuneate fasciculus E. None of the above ## Footnote In a caudalis dorsal root entry zone (DREZ) operation, the electrode pene- trates the dorsal spinocerebellar tract into the trigeminal tract and deeper caudalis nucleus.

Answer 445

A. has no corresponding area in the intracranial pressure (ICP) waveform. B. corresponds to the area between P1 and P2 of the ICP waveform. **C. corresponds to the area between P2 and P3 of the ICP waveform.** D. corresponds to the area after P3 of the ICP waveform. E. None of the above ## Footnote The arterial dicrotic notch corresponds to the area between the tidal (P2) and dicrotic (P3) peaks of the ICP waveform.

Answer 446

**A. Anterior perforated substance** B. Posterior perforated substance C. Tuber cinereum D. Medial geniculate body E. Lateral geniculate body ## Footnote The basal vein of Rosenthal receives tributaries from the medial temporal lobe and brainstem. It begins at the anterior perforated substance.

Answer 447

A. frontal horn. B. third ventricle. **C. trigone of lateral third ventricle.** D. occipital horn. E. foramen of Monro ## Footnote The trigone of the lateral ventricle is a triangular area defined by the tempo- ral horn inferiorly, the occipital horn posteriorly, and the body of the lateral ventricle anteriorly.

Answer 448

A. Cerebellum B. Rostral midbrain C. Rostral pons **D. Caudal midbrain** E. Caudal pons ## Footnote Decussation of the superior cerebellar peduncles occurs in the caudal mid- brain tegmentum at the level of the inferior colliculus. The superior cere- bellar peduncle is one of the structures that connects the cerebellum to the midbrain. The ventral spinocerebellar tract enters the cerebellum through the superior cerebellar peduncle.

Answer 449

A. superior thyroid artery. **B. ascending pharyngeal artery.** C. lingual artery. D. facial artery. E. occipital artery. ## Footnote The ascending pharyngeal artery supplies these nerves before anastomosing with vertebral artery branches. This artery also supplies the pharynx.

Answer 450

A. ipsilateral lateral and medial rectus palsies. **B. ipsilateral lateral and contralateral medial rectus palsies.** C. contralateral lateral and ipsilateral medial rectus palsies. D. contralateral lateral and medial rectus palsies. E. None of the above ## Footnote Destruction of the abducens nucleus (subcortical center for lateral gaze) re- sults in an ipsilateral lateral rectus and contralateral medial rectus palsy on attempted lateral gaze.

Answer 451

A. the medial lemniscus. **B. the lateral lemniscus.** C. the corticospinal tracts. D. All of the above E. None of the above ## Footnote Brainstem auditory evoked responses test the ear and the brain. They meas- ure the timing of electrical waves from the brainstem in response to clicks in the ear. Waveforms represent specific anatomical points along the auditory pathway.

Answer 452

A. the inferior rectus. B. the inferior oblique. C. the medial rectus. **D. All of the above** E. None of the above ## Footnote The lateral subnucleus of CN III innervates the inferior rectus, inferior oblique, and medial rectus. The medial subnucleus innervates the contralat- eral superior rectus. The central subnucleus innervates the levator palpebrae superioris.

Answer 453

A. Brodmann area 3a. B. Brodmann area 3b. **C. Brodmann area 2.** D. Brodmann area 1. E. None of the above ## Footnote The primary sensory cortex is Brodmann areas 3, 1, and 2. This area of the cortex is organized somatotopically, having the pattern of a homunculus

Answer 454

A. Symmetric involvement **B. Pain** C. Saddle anesthesia D. Bladder and bowel symptoms E. Sudden onset ## Footnote Pain is more common in cauda equina lesions than in conus lesions. Motor loss is more marked in cauda lesions, and bladder and rectum are involved later in cauda lesions. The onset of cauda lesions is more gradual than that of conus lesions. Also cauda lesions are more commonly unilateral than co- nus lesions. Cauda equina lesions can occur with compression in the lower lumbar region, they are a medical emergency, and patients should be admit- ted with urgent surgery to decompress the nerves and stabilize the spine if necessary. Approximately 1% of a busy spine practice can be cauda equina conditions, yet insurance companies and some hospitals will incorrectly and unethically insist that such surgeries can be performed electively at a later time for cost savings.

Answer 455

A. III. B. IV. **C. V.** D. VI. E. VII. ## Footnote MPNSTs are also known as schwannomas, neurofibrosarcomas, and neuro- sarcomas. The trigeminal nerve is most commonly involved only because it is the largest cranial nerve.

Answer 456

A. IV (trochlear) and V (trigeminal) B. III (oculomotor) and IV C. III and II (optic) **D. V and VI (abducens)** E. II and IV ## Footnote The superior ophthalmic vein courses into the anterior cavernous sinus above the sixth nerve and below the first division of the trigeminal nerve. The superior ophthalmic vein is exterior to the annulus of Zinn.

Answer 457

A. the medial wall of the frontal horn. B. the fl oor of the temporal horn. C. the lateral wall of the occipital horn. D. the roof of the lateral ventricle. **E. None of the above.** ## Footnote The caudate nucleus forms the lateral wall of the frontal horn, body, and trigone of the lateral ventricle. It forms the roof of the temporal horn. The caudate does not extend to the occipital horn. The caudate nucleus makes up the basal ganglia along with the putamen and globus pallidus.

Answer 458

A. It arises from the principal sensory nucleus of V. B. It terminates on the VPM thalamus. C. It conveys touch and pressure information from the face. D. It is an uncrossed tract. **E. All of the above** ## Footnote The dorsal trigeminothalamic tract is the rostral equivalent of the dorsal-col- umn medial-lemniscal system.

Answer 459

A. Skin B. Subcutaneous tissue C. Galea **D. Loose areolar tissue** E. Periosteum ## Footnote The loose areolar tissue contains the valveless emissary veins. Emissary veins connect the extracranial venous system with the intracranial venous sinuses.

Answer 460

**A. Adrenergic fi bers** B. Cholinergic fi bers C. Nitric Oxide D. VIP E. None of the above ## Footnote Apocrine sweat glands of the axilla are innervated by adrenergic fibers and secrete in response to mental stress. The eccrine sweat glands have choliner- gic innervation.

Answer 461

A. Just after birth **B. Childhood** C. Adolescence D. Young adulthood E. Late adulthood ## Footnote The water content of the nucleus pulposus is maximum at birth and declines throughout life, the greatest decline occurring during the growth phase in childhood.

Answer 462

A. the claustrum. B. the globus pallidus. **C. the corpus callosum.** D. the thalamus. E. None of the above ## Footnote The tapetum are corpus callosum fibers connecting the temporal and occip- ital lobes.

Answer 463

A. dominant frontal lobe. B. nondominant frontal lobe. C. dominant parietal lobe. **D. nondominant parietal lobe.** E. occipital lobe. ## Footnote Apraxia is a disorder of motor planning. Dressing apraxia can be tested by having the patient put on a jacket with the sleeves first deliberately turned inside-out.

Answer 464

A. valveless arachnoid villi. B. pressure-insensitive valves of the arachnoid villi. **C. pressure-sensitive one-way valves of the arachnoid villi.** D. pressure-insensitive valveless arachnoid villi. E. cranial nerves ## Footnote Cerebrospinal fluid is reabsorbed into the bloodstream through pressure-sen- sitive one-way valves in the arachnoid villi.

Answer 465

A. CLIP. B. beta-lipotropin. C. alpha-MSH. **D. POMC.** E. p53. ## Footnote Proopiomelanocortin (POMC) gives rise to adrenocorticotropic hormone (ACTH) and beta-lipotropin. ACTH gives rise to alpha-MSH and CLIP. Beta-li- potropin gives rise to beta-endorphin and gamma-lipotropin.

Answer 466

A. It involves autoantibodies directed against acetylcholine receptors at the neuromuscular junction, B. The prevalence is between 1 in 10,000 to 15,000. C. Juvenile MG is more common in Asians. D. There is an increased incidence of an underlying thymoma in late onset MG. **E. Late-onset MG is more common in females.** ## Footnote Late-onset myasthenia gravis (onset after age 50) is more common in males. Early-onset myasthenia gravis (onset from ages 18 to 50) is more common in females.

Answer 467

A. sphenoid bone. B. occipital bone. C. sphenoid and temporal bones. **D. temporal bone.** E. temporal and occipital bones. ## Footnote The ICA enters the cranium via the carotid canal of the temporal bone.

Answer 468

A. It has a nucleus located in the midbrain tegmentum at the level of the inferior colliculus. B. It decussates in the superior medullary velum. C. It exits the brainstem from the dorsal surface of the brainstem. D. It courses lateral to the frenulum of the superior medullary velum. **E. Damage to the nucleus results in dysfunction of the superior oblique muscle on that side.** ## Footnote Damage to the trochlear nucleus results in damage to the contralateral superior oblique because the fibers decussate in the superior medullary velum.

Answer 469

**A. the lambdoid, occipitomastoid, and parietomastoid sutures.** B. the lambdoid, sagittal, and occipitomastoid sutures. C. the lambdoid, sagittal and parietomastoid sutures. D. the sagittal and occipitomastoid sutures. E. None of the above ## Footnote The asterion is located at the intersection of the lambdoid, occipitomastoid, and parietomastoid sutures. This point reliably marks the anteroposterior level of the transverse-sigmoid sinus junction.

Answer 470

A. Posterior nucleus B. Ventromedial nucleus C. Lateral nucleus **D. Anterior nucleus** E. None of the above ## Footnote The anterior nucleus of the hypothalamus is involved in thermal regulation (dissipation of heat). The anterior nucleus stimulates the parasympathetic nervous system. Destruction of this nucleus results in hyperthermia.

Answer 471

A. Occipitoatlantal joint B. Atlantoaxial joint C. Sacrum **D. All of the above** E. None of the above ## Footnote Disks make up roughly 25% of the spine’s height. There is no disk at the occip- itoatlantal joint, atlantoaxial joint, sacrum, or coccyx. Traction and inversion table therapy can help to slow down the desiccation and shortening of disk space height.

Answer 472

A. Serum sodium < 135 mEq/L B. Serum osmolarity < 280 mOsm/L **C. Hypervolemia** D. Urine sodium > 20 mmol/24 h E. Urine osmolarity > serum osmolarity ## Footnote SIADH is a type of hyponatremia characterized by euvolemia.

Answer 473

A. Gunn’s syndrome B. Joubert’s syndrome C. De Morsier’s syndrome **D. Duane’s syndrome** E. None of the above ## Footnote Duane’s syndrome produces a characteristic pattern of eye movement with failure of abduction and retraction of the globe on adduction; the third nerve innervates the lateral rectus due to developmental failure of motor neurons in the sixth nerve nucleus. Alexander Duane was an American ophthalmolo- gist who published “A New Classification of the Motor Anomalies of the Eye” in 1897.

Answer 474

A. Cimetidine B. Coumadin **C. Carbamazepine** D. Isoniazid E. Sulfa drugs ## Footnote Dilantin levels are decreased by carbamazepine.

Answer 475

**A. Olivocerebellar** B. Reticulocerebellar C. Pontocerebellar D. All of the above E. None of the above ## Footnote Olivocerebellar fibers end as climbing fibers, and aspartate is a common neu- rotransmitter in this connection. Reticulocerebellar and pontocerebellar fib- ers end as mossy fibers.

Answer 476

**A. tumor location.** B. tumor size. C. time to surgery. D. chemotherapy and radiation. E. None of the above ## Footnote Paraganglioma is a rare neuroendocrine neoplasm the great majority of which are benign. About 3% of these tumors are malignant and are able to produce distant metastases. Tumor location is often more relevant than histology and other factors in assessing the prognosis of paraganglioma pa- tients. For example, the metastatic rate of para-aortic paraganglioma is high (~ 30%), whereas that of carotid body tumors is much lower (~ 6%). Most paragangliomas are either asymptomatic or present as a painless mass.

Answer 477

A. IV and V1. **B. V1 and V2.** C. V2 and V3. D. V3 and VI. E. None of the above ## Footnote The anteromedial triangle of the middle fossa can be used to expose portions of the cavernous sinus and lateral sphenoid wing.

Answer 478

A. Subcortical white matter of the occipital lobes bilaterally with little to no edema **B. Subcortical white matter of the occipital lobes bilaterally with edema** C. The cortical ribbon of the parietal lobes bilaterally D. The cortical ribbon and subcortical white matter bilaterally E. The cortical ribbon with sparing of the subcortical U-fibers ## Footnote Hyperperfusion encephalopathy is believed to result from the failure of intrac- ranial vessels to compensate adequately for rapid increases of blood pressure. The posterior brain regions exhibit reversible edema bilaterally. This condi- tion is also known as PRES (posterior reversible encephalopathy syndrome). Patients can present with headaches, seizures, and/or visual disturbances.

Answer 479

**A. Foramen ovale and spinosum** B. Foramen ovale and rotundum C. Foramen rotundum and spinosum D. Foramen spinosum and lacerum E. Foramen lacerum and ovale ## Footnote Glasscock’s triangle is also known as the posterolateral triangle. Its contents are the foramen spinosum, horizontal petrous ICA, and infratemporal fossa.

Answer 480

A. The vast majority of patients recover completely. B. The edema tends to resorb completely. **C. The vertebrobasilar system is vulnerable due to extensive sympathetic innervation.** D. A similar condition may occur after a carotid endarterectomy. E. Patients with hyperperfusion encephalopathies often have labile blood pressures. ## Footnote The posterior circulation has sparse sympathetic innervation and is less well protected from hyperperfusion encephalopathies.

Answer 481

A. It separates the frontal lobe from the parietal lobe. B. It separates the motor cortex from the sensory cortex. C. It extends into the paracentral lobule. **D. It is usually continuous with the lateral sulcus.** E. It is located on the lateral convex surface of the hemisphere. ## Footnote The central sulcus rarely joins the lateral sulcus. The central sulcus separates the parietal lobe from the frontal lobe and the primary motor cortex from the primary sensory cortex. This was originally called the fissure of Rolando after Luigi Rolando, an Italian anatomist who published extensively on brain anatomy and function in the 1800s.

Answer 482

A. Normal intraocular pressure **B. Ipsilateral flushing** C. Decreased local skin temperature D. Female predominance E. No aura is seen with common migraines ## Footnote Ipsilateral flushing is seen with cluster headaches. Cluster headaches also have an increased intraocular pressure, increased local skin temperature, and male predominance, and are seen in older patients. Migraine headaches can be improved with Botox (Allergan) injections to the scalp musculature. Many patients given the diagnosis of migraine headaches may have cervicogenic headaches, and a cervical MRI is helpful in determining this. Cervicogenic headaches have a characteristic triad of headache, pressure behind the eye, and a swooshing sound (or tinnitus) in the ear.

Answer 483

A. Anton’s syndrome. B. Adie’s syndrome. C. Cogan’s syndrome. D. Vernet’s syndrome. **E. Balint’s syndrome.** ## Footnote The syndrome described is Balint’s syndrome. It is of interest to note that functional “streams” of visual processing have been postulated. The “where” stream is destined for further processing in the parietal lobes and subserves spatial localization and the control of eye movements. The “what” stream is destined for the temporal lobes and is concerned with the identification of objects and color vision. Evidence for this came from studying patients with Balint’s syndrome.

Answer 484

A. the basal ganglia. B. the anterior commissure. C. the caudate nucleus. **D. All of the above** E. None of the above ## Footnote The amygdala is not removed completely in this procedure. The most medial part abuts the basal ganglia, anterior commissure, and tail of the caudate.

Answer 485

**A. Lateral, parallel** B. Medial, parallel C. Lateral, perpendicular D. Medial, perpendicular E. None of the above ## Footnote The anterior choroidal artery can be divided into two segments: the cisternal segment extends from its origin until the choroidal fissure and the intraven- tricular segment after entering the choroidal fissure.

Answer 486

A. Piriformis B. Obturator internus C. Quadratus femoris **D. Gluteus minimus** E. Gluteus maximus ## Footnote The gluteus minimus is a medial rotator of the thigh. The others listed are all lateral rotators. The gluteus minimus is the smallest of the three gluteal muscles. Paralysis of this muscle may be caused by a superior gluteal nerve palsy.

Answer 487

A. Parkinson’s disease B. Shy–Drager’s syndrome **C. Multiple system atrophy** D. Diffuse Lewy body dementia E. Paralysis agitans ## Footnote Lewy bodies are concentrically laminated, round bodies found in vacuoles in the cytoplasm. They are absent in multiple system atrophy (MSA). Lewy bodies were discovered by Frederic Lewy, an American neurologist.

Answer 488

A. septal vein. **B. thalamostriate vein.** C. caudate vein. D. basal vein of Rosenthal. E. vein of Galen. ## Footnote The thalamostriate vein lies in the groove between the thalamus and caudate nucleus and receives blood from both.

Answer 489

A. anterior to the target. **B. posterior to the target.** C. medial to the target. D. lateral to the target. E. close to the target. ## Footnote Paresthesias of the fingertips or mouth indicate that the electrode is too pos- terior (in the region of the ventralis caudalis [VC]). The electrode needs to be repositioned more anteriorly. High-frequency stimulation of the VC causes contralateral paresthesias. The threshold for inducing contralateral paresthe- sias is higher in the ventralis intermedius (Vim) (target), and it is usually > 3 V.

Answer 490

A. Streptococcus pneumoniae. B. Haemophilus influenzae. **C. Neisseria meningitidis.** D. Proteus. E. None of the above ## Footnote Deficiency of the late complement components predisposes to Neisseria meningitidis. Deficiency of early complement components tend to be linked with autoimmune diseases. Complement deficiencies are said to comprise between 1 and 10% of all primary immunodeficiencies.

Answer 491

A. body. **B. trigone.** C. temporal horn. D. occipital horn. E. frontal horn. ## Footnote Meningiomas and choroid plexus papillomas are the most common neo- plasms of the trigone of the lateral ventricle. Meningiomas originate from the arachnoid cap cells of the choroid plexus and the tela choroidea. Intraven- tricular meningiomas present in mid adulthood with a female predilection.

Answer 492

A. the size of the largest metastasis. **B. the extent of systemic disease.** C. the number of visible metastases on MRI scan. D. the neurological condition preoperatively. E. proximity to the eloquent cortex. ## Footnote The status of systemic disease is the most important determinant for survival.

Answer 493

A. Ia (A-). **B. Ib (A-).** C. II (A-). D. III (A-). E. IV (C). ## Footnote Golgi tendon organs are associated with Ib (A-a) fibers. Muscle spindles are associated with Ia (A-a) fibers. Slow pain and temperature are carried by un- myelinated fibers IV (C).

Answer 494

A. caused by staphylococci; occur in the cervical cord. B. caused by streptococci; occur in the cervical cord. **C. caused by staphylococci; occur in the thoracic cord.** D. caused by streptococci; occur in the thoracic cord. E. caused by staphylococci; occur in the lumbar cord. ## Footnote Staphylococcus aureus causes ~ 60–90% of cases of spinal epidural abscesses. The most frequent location is the thoracic epidural space.

Answer 495

A. Staphylococcus is the organism implicated in a majority of cases. B. Symptoms include shunt failure, headache, nausea, and vomiting. C. Elevated temperature is a more reliable sign of infection in VA as opposed to VP shunts. **D. There is a greater risk of shunt infection with distal revision than with proximal revision.** E. Staphylococcus infections may cause obstruction without fever. ## Footnote There is a greater risk of shunt infection with proximal revisions.

Answer 496

A. Liposarcoma **B. Fibrosarcoma** C. Angiosarcoma D. Chondrosarcoma E. Osteosarcoma ## Footnote The development of sarcomas after cranial irradiation is well described. Fi- brosarcomas are the most common type arising in the sella after irradiation for pituitary tumors.

Answer 497

A. disinhibition of the subthalamic nucleus. B. high activity of Gpi/SNr. C. inhibition of the motor thalamus. **D. All of the above** E. None of the above ## Footnote Dopamine plays a central role in Parkinson’s disease, attention deficit hyper- activity disorder, schizophrenia, and drug addiction.

Answer 498

A. It is due to disruption of the pituitary stalk. B. There is degeneration of distal axons in the region of dissection. C. Stored ADH is depleted. **D. All of the above** E. None of the above ## Footnote The sequence of antidiuretic hormone (ADH) release after surgery is tripha- sic. Initially, excessive diuresis is due to disruption of the pituitary stalk. Then there is a release of ADH in large amounts from degeneration of distal axons. Finally the stored ADH disappears, and excessive diuresis returns

Answer 499

A. Strongyloides B. Schistosomiasis C. Paragonimiasis D. Neurocysticercosis **E. Echinococcus** ## Footnote Patients with infection commonly present with cord compression due to the predilection of echinococcus for bone, particularly vertebrae. With- in bone tissue hyatid cysts enlarge by daughter cyst formation. The goal of surgery is removal of the cysts; an anterior or circumferential approach is recommended.

Answer 500

A. cingulated gyrus. **B. prefrontal cortex.** C. substantia nigra. D. lateral lemniscus. E. inferior parietal lobule. ## Footnote The mediodorsal nucleus is reciprocally connected to the prefrontal cortex. The prefrontal cortex is the cerebral cortex, which covers the front part of the frontal lobe. It contains Brodmann areas 9, 10, 11, 12, 46, and 47.

Answer 501

A. subependyma. B. gray–white junction. **C. meninges.** D. frontal lobe. E. corpus callosum. ## Footnote Lymphoma metastatic to the brain tends to localize to the meninges, as op- posed to the intraparenchymal (often subependymal) location of primary tumors.

Answer 502

A. Anterior commissure B. Posterior commissure **C. Hippocampal commissure** D. All of the above E. None of the above ## Footnote The hippocampal commissure is located in the posterior component of the forniceal structure.

Answer 503

A. It is the largest of the intralaminar nuclei. B. It receives input from the globus pallidus. C. It projects to the striatum. D. It projects diffusely to the entire neocortex. **E. It is reciprocally connected to areas 41 and 42.** ## Footnote The centromedian nucleus is reciprocally connected to the motor cortex (area 4).

Answer 504

A. Medial, anterior **B. Medial, posterior** C. Lateral, anterior D. Lateral, posterior E. None of the above ## Footnote During surgery around the mastoid process, care must be taken to avoid inju- ry to cranial nerve VII as it exits through the stylomastoid foramen, which is located medial to the insertion of the posterior belly of the digastric muscle at the digrastric groove.

Answer 505

A. division of the anterior corpus callosum. B. retraction on the fornix. C. circulatory disturbance in the SMA. **D. All of the above** E. None of the above ## Footnote In addition, postoperative amnesia may result from manipulation of the fornix.

Answer 506

A. Dentate nucleus B. Globose nucleus C. Emboliform nucleus **D. All of the above** E. None of the above ## Footnote The rostral one-third of the red nucleus receives dentate fibers, and the cau- dal two-thirds receive fibers from the interposed nuclei. Stimulation of the red nucleus elicits increased tone in the contralateral flexors. The red nucleus gets its pale pink color from hemoglobin and ferritin, which are present in the red nucleus.

Answer 507

A. Phentolamine B. Atropine C. Phenylephrine D. Amphetamine **E. Phenoxybenzamine** ## Footnote Phenoxybenzamine is a nonselective, irreversible alpha blocker used in the treatment of hypertension, especially hypertension caused by pheochromo- cytoma. It is also used in complex regional pain syndrome type 1 due to its antiadrenergic effects.

Answer 508

A. Forty percent of the energy consumed is for maintenance of ionic gradients. B. Once EEG silence is induced, barbiturates will not produce further reductions in (CMRO2). C. Once EEG silence is induced, temperature reduction does produce further reductions in (CMRO2). D. The normal rate is ~5 mL/100 g brain/min. **E. Ketamine anesthesia decreases CMRO2.** ## Footnote Ketamine anesthesia increases CMRO2. All other anesthetic drugs decrease CMRO2. The main energy demands of the brain are those of ion flux related to excitation and conduction. Continuous cerebral circulation is absolutely required to provide sufficient oxygen.

Answer 509

A. Centromedian B. Ventral anterior C. Ventral lateral **D. All of the above** E. None of the above ## Footnote The globus pallidus projects to three thalamic nuclei via the thalamic fascic- ulus (FFH1).

Answer 510

A. posterior cerebral artery. B. posterior choroidal artery. C. middle cerebral artery. **D. anterior choroidal artery.** E. occipital artery. ## Footnote The major blood supply to ventricular trigone meningiomas is constant, aris- ing from the anterior choroidal artery, with only a minor component arising from the posterior choroidal artery.

Answer 511

A. -fetoprotein B. -HCG C. CBC, PT, PTT **D. All of the above** E. None of the above ## Footnote Elevated markers are indicative of malignant germ cell tumors, and these tumors can be radiosensitive and chemosensitive, precluding surgery.

Answer 512

**A. frontopontine.** B. corticobulbar. C. corticospinal. D. parietopontine. E. sympathetic fibers. ## Footnote The crus cerebri is the anterior portion of the cerebral peduncle, which con- tains motor tracts.

Answer 513

A. 11. B. 10. **C. 9.** D. 8. E. 7. ## Footnote The Glasgow Coma Scale (GCS) score is 9. She opens eyes to pain (2) and mumbles sounds (2), and the best motor response is localizing (5). Always take the best motor response when assessing GCS. An intracerebral pressure monitor may not be indicated with a patient who is localizing. The CT brain and neuro exam can guide treatment in this particular patient.

Answer 514

A. Glioblastoma multiforme **B. Hemangiopericytoma** C. Ewing’s sarcoma D. Sinonasal carcinoma metastases E. Breast carcinoma metastases ## Footnote (Or C.) Ewing’s sarcoma may present with involvement of the dura, skull, and possibly the underlying parenchyma.

Answer 515

A. Glioblastoma multiforme B. Hemangiopericytoma C. Ewing’s sarcoma D. Sinonasal carcinoma metastases **E. Breast carcinoma metastases** ## Footnote This is a calvarial metastases, an occurrence observed not uncommonly with metastatic breast carcinoma.

Answer 516

A. Glioblastoma multiforme B. Hemangiopericytoma C. Ewing’s sarcoma **D. Sinonasal carcinoma metastases** E. Breast carcinoma metastases ## Footnote Sinunasal carcinoma may metastasize to multiple dural-based locations.

Answer 517

A. Multiple myeloma **B. Recurrence after maximal radiation** C. Multiple lesions at multiple levels D. Total paralysis for > 48 hours E. Expected survival < 3 months B. Recurrence after maximal radiation is an indication to operate

Answer 518

A. 20 Gy in 2 Gy fractions over 10 days **B. 30 Gy in 3 Gy fractions over 10 days** C. 60 Gy in 6 Gy fractions over 10 days D. 100 Gy in 10 Gy fractions over 10 days E. 200 Gy in 50 Gy fractions over 30 days

Answer 519

A. Tetanus B. Botulism **C. Diphtheria** D. Reye’s syndrome C. Diphtheria toxin has a predilection to sensory and motor nerves of the limbs and ciliary muscles or nerves.

Answer 520

**A. Tetanus** B. Botulism C. Diphtheria D. Reye’s syndrome A. Tetanus may typically present with trismus, risus sardonicus, tonic spasms, and generalized convulsions.

Answer 521

**Botulism* B. Symptoms appear 12–48 hours after ingestion and may be preceded by nausea, vomiting, and diarrhea. The convergence diffi culty is usually followed by ptosis and extraocular muscle paralysis

Answer 522

**D. This is a typical feature of Reye’s syndrome.**

Answer 523

A. Biopsy-proven plasmacytoma **B. Myeloma cells in a single peripheral blood smear** C. Plasma cells > 10 of 1000 cells on marrow morphology D. Radiographic survey demonstrating lytic lesions E. Monoclonal immunoglobulins in the urine or blood B. Myeloma cells in two or more peripheral blood smears are required

Answer 524

A. Hypocalcemia occurs in 25% of patients. B. Bone pain is characteristically at rest and with movement. **C. There is occurrence of amyloidosis.** D. Invasion of the spinal canal occurs in over 50% of patients. E. Defi nitive diagnosis can be made by plain X-ray Patients with spinal multiple myeloma typically present with hypercalcemia, bone pain characteristically absent at rest, and spinal canal invasion in about 10% of cases. Multiple myeloma (MM) and amyloid light-chain (AL) amyloidosis are caused by the expansion of monoclonal plasma cells and secretion of dysproteinemia (Bence Jones protein and free light chain)

Answer 525

A. Perinervous B. Arterial **C. Venous** D. Direct extension E. All of the above It represents spread via spinal epidural veins. The Batson venous plexus is a network of valveless veins in the human body that connect the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses.

Answer 526

C. Facioscapulohumoral dystrophy, or Landouzy-Dejerine’s syndrome is associated with a defect on chromosome 4

Answer 527

A. Werdnig-Hoff mann’s disease has autosomal recessive inheritance on chromosome 5q

Answer 528

E. Myotonic muscular dystrophy has autosomal dominant inheritance on chromosome 1

Answer 529

B. Cri du chat syndrome is due to a 5p deletion and results in microcephaly, hypertelorism, and congenital heart disease.

Answer 530

B. Diltiazem is the preferred agent for patients with systolic heart failure because it produces less myocardial depression than verapamil.

Answer 531

A. Verapamil’s side effects include hypotension and worsening of systolic heart failure due to negative inotropic eff ect.

Answer 532

C. Digoxin is indicated for chronic rate control of atrial fi brillation. Because of its delayed action it is not indicated in acute atrial fi brillation.

Answer 533

D. Procainamide is contraindicated in patients with prolonged QT interval because it prolongs QT interval and may be pro-arrhythmic. It is used to convert atrial fi brillation to normal sinus rhyth

Answer 534

E. Beta-blockers are indicated for rate control of atrial fibrillation in the setting of a hyperadrenergic state such as acute myocardial infarction after bypass surgery

Answer 535

A. ganglioglioma. **B. gliosarcoma** C. glioblastoma multiforme. D. gliomatosis cerebri. E. germinoma Gliosarcoma has the same histological features as glioblastoma multiforme. In addition, it does stain for reticulin in the sarcomatous part of the tumor. Approximately 2% of glioblastomas are gliosarcomas.

Answer 536

A. Those with mild neurological defi cits and accessible lesions are better managed by repair than ligation. B. Proximal occlusion may be accomplished by an anterior approach with mobilization of the sternocleidomastoid. C. Endovascular embolization with detachable balloons may be used for management. **D. All of the above are true.** E. None of the above are true. Blunt trauma injuries to the cervical vertebral artery are more often managed by ligation than repair. Ligation may be risky since only ~ 20% of the general population has a complete collateral circulation. Proximal occlusion may be accomplished by an anterior approach with mobilization of the sternocleidomastoid. Endovascular treatment with detachable balloons is a valid option for management

Answer 537

C. Arsenic causes peripheral neuropathy, nausea, and vomiting

Answer 538

E. Lead causes encephalitis in children as well as pica, irritability, seizures, abdominal cramping, ataxia, coma, and high intracrania

Answer 539

B. Manganese causes a Parkinson-like syndrome.

Answer 540

A. Mercury causes peripheral neuropathy, cerebellar signs, psychological dysfunctions, tremor, movement disorders, and renal tubular necrosis

Answer 541

D. Aluminum may present with a picture of Alzheimer’s disease

Answer 542

**A. Left atrium** B. Left ventricle C. Pulmonary veins D. Aorta E. Ventricular aneurysms A. Left atrium accounts for 65–75% of embolisms, mainly the left appendage. The left ventricle and ventricular aneurysms account for 5% each

Answer 543

A. Diabetic ketoacidosis B. Cushing’s syndrome C. High intestinal obstruction D. Chronic diarrhea **E. Uremia** E. Uremia is most likely to cause potassium stores depletion.

Answer 544

A. Seizures **B. Tetany** C. Hypotension D. Loss of deep tendon reflexes E. Stupor Tetany is the fi rst sign of magnesium depletion. Delirium occurs usually before convulsions. An increase in deep tendon refl exes is usually observed.

Answer 545

A. Na+ 130 mEq/L B. Cl· 109 mEq/L C. Lactate 28 mEq/L **D. Ca2+ 16 mEq/L** E. K+ 4 mEq/L

Answer 546

A. The male to female ratio is 1.5:1. **B. Thoracic location is the most common.** C. It is usually low grade. D. It is the most common intramedullary tumor in children. E. Examination may reveal a combination of upper and lower motor neuron signs. The MRI scan demonstrates an intramedullary astrocytoma, which occurs most commonly in the cervical spine. Lower motor signs may be at the level of the lesion and may aid in localization. These types of tumors are the most common intramedullary tumors in children and are usually of fi brillary type. Intramedullary tumors may be treated empirically with cyberknife radiosurgery with good results forgoing the need for biopsy which can be risky. A lumbar puncture may be used for an indirect biopsy which is reasonably safe. It is however low yield but worth a try.

Answer 547

A. Amyotrophic lateral sclerosis B. Systemic lupus erythematosus **C. Metachromatic leukodystrophy** D. Lesch–Nyhan syndrome E. Niemann–Pick disease

Answer 548

**A. Amyotrophic lateral sclerosis** B. Systemic lupus erythematosus C. Metachromatic leukodystrophy D. Lesch–Nyhan syndrome E. Niemann–Pick disease

Answer 549

A. Amyotrophic lateral sclerosis B. Systemic lupus erythematosus C. Metachromatic leukodystrophy **D. Lesch–Nyhan syndrome** E. Niemann–Pick disease

Answer 550

A. Increased calcium, normal phosphate, and increased alkaline phosphatase B. Decreased calcium, increased phosphate, and normal alkaline phosphatase **C. Decreased calcium, decreased phosphate, and increased alkaline** phosphatase D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 551

A. Increased calcium, normal phosphate, and increased alkaline phosphatase B. Decreased calcium, increased phosphate, and normal alkaline phosphatase C. Decreased calcium, decreased phosphate, and increased alkaline phosphatase **D. Normal calcium, normal phosphate, and increased alkaline phosphatase**

Answer 552

**A. Increased calcium, normal phosphate, and increased alkaline phosphatase** B. Decreased calcium, increased phosphate, and normal alkaline phosphatase C. Decreased calcium, decreased phosphate, and increased alkaline phosphatase D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 553

A. Increased calcium, normal phosphate, and increased alkaline phosphatase B. Decreased calcium, increased phosphate, and normal alkaline phosphatase C. Decreased calcium, decreased phosphate, and increased alkaline phosphatase **D. Normal calcium, normal phosphate, and increased alkaline phosphatase**

Answer 554

A. Increased calcium, normal phosphate, and increased alkaline phosphatase **B. Decreased calcium, increased phosphate, and normal alkaline phosphatase** C. Decreased calcium, decreased phosphate, and increased alkaline phosphatase D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 555

A. Chronic respiratory acidosis B. Non-anion gap metabolic acidosis and respiratory alkalosis C. Metabolic alkalosis and respiratory acidosis D. Wide anion gap metabolic acidosis **E. Chronic respiratory alkalosis**

Answer 556

A. Chronic respiratory acidosis **B. Non-anion gap metabolic acidosis and respiratory alkalosis** C. Metabolic alkalosis and respiratory acidosis D. Wide anion gap metabolic acidosis E. Chronic respiratory alkalosis

Answer 557

A. Chronic respiratory acidosis B. Non-anion gap metabolic acidosis and respiratory alkalosis **C. Metabolic alkalosis and respiratory acidosis** D. Wide anion gap metabolic acidosis E. Chronic respiratory alkalosis

Answer 558

**A. Chronic respiratory acidosis** B. Non-anion gap metabolic acidosis and respiratory alkalosis C. Metabolic alkalosis and respiratory acidosis D. Wide anion gap metabolic acidosis E. Chronic respiratory alkalosis

Answer 559

A. Chronic respiratory acidosis B. Non-anion gap metabolic acidosis and respiratory alkalosis C. Metabolic alkalosis and respiratory acidosis **D. Wide anion gap metabolic acidosis** E. Chronic respiratory alkalosis Here are some pointers in interpreting the arterial blood gas: The most useful information comes from the clinical description of the patient by the history and physical examination; however in this case this information is not given. Therefore, the next step is to look at the pH. If pH < 7.35, then there is an acidemia; if pH > 7.45, then there is an alkalemia. The pH may be normal in the presence of a mixed acid base disorder, particularly if other parameters of the ABG are abnormal. The third step is to look at PCO2 and HCO3- in order to determine the acid base process (alkalosis vs. acidosis) leading to the abnormal pH. In simple acid base disorders, both values are abnormal and direction of the abnormal change is the same for both parameters. One abnormal value will be the initial change and the other will be the compensatory response. Once the initial change is identifi ed, then the other abnormal parameter is the compensatory response if the direction of the change is the same. If not, suspect a mixed disorder. Once the initial chemical change and the compensatory response is distinguished, then identify the specifi c disorder. If PCO2 is the initial chemical change, then the process is respiratory; if HCO3- is the initial change, then the process is metabolic. Below is a brief description of the initial chemical change followed by the compensatory response in basic acid/base disorders: Respiratory Acidosis PCO2 HCO3- Respiratory Alkalosis PCO2 HCO3- Metabolic Acidosis HCO3- PCO2 Metabolic Alkalosis HCO3- PCO2

Answer 560

A. Scan 1 B. Scan 2 **C. Scans 1 and 2** D. None of the above

Answer 561

A. Scan 1 **B. Scan 2** C. Scans 1 and 2 D. None of above

Answer 562

**A. Scan 1** B. Scan 2 C. Scans 1 and 2 D. None of the above

Answer 563

A. the tuberoinfundibular nucleus. **B. the preoptic nucleus.** C. the paraventricular nucleus. D. the mammillary bodies. E. None of the above B. The preoptic nucleus is considered part of the anterior hypothalamus.

Answer 564

A. Adie’s pupil B. Posterior communicating artery aneurysm **C. Kennedy syndrome** D. Horner’s syndrome E. Third nerve lesion C. All the other choices result in an eff erent defect.

Answer 565

A. Macular degeneration B. Optic neuritis C. Papilledema **D. Metabolic optic neuropathy** E. Retinal lesion ## Footnote .D. Metabolic neuropathy is typically symmetric and bilateral and will rarely present with an aff erent pupillary defect clinically

Answer 566

A. Decreasing the positive end expiratory pressure to 0 cm H2O B. Hyperventilation **C. Improving mixed venous oxygen contents** D. Oxygen supplementation E. None of the above ## Footnote An improvement in mixed venous oxygen contents will often improve the hypoxemia in the setting of a shunt.

Answer 567

A. 96 hours. **B. 72 hours.** C. 48 hours. D. 24 hours. E. 12 hours ## Footnote The half-life is 72 hours.

Answer 568

A. Conversion of prothrombin to thrombin **B. Activation of contact factors** C. Generation of thromboplastin D. Release of phospholipids from platelets E. Conversion of fi brinogen to fi brin ## Footnote Conversion of prothrombin from thrombin is the most time consuming and is usually measured as the prothrombin time (PT); it is in the range of 11 to 13 seconds.

Answer 569

B. ## Footnote The second fi gure shows a venous angioma which can be caused by arrested development.

Answer 570

**D** ## Footnote Dural arteriovenous malformations are usually acquired after dural thrombosis. Neither cavernous malformation (fi rst image) nor venous angioma (second image) is an acquired lesion

Answer 571

**B** ## Footnote Blue rubber nevus syndrome is associated with venous angiomas

Answer 572

A. Ocular bobbing B. Jerk nystagmus C. See-saw nystagmus **D. Downbeat nystagmus** E. None of the above

Answer 573

A. Ocular bobbing B. Jerk nystagmus **C. See-saw nystagmus** D. Downbeat nystagmus E. None of the above

Answer 574

A. Ocular bobbing **B. Jerk nystagmus** C. See-saw nystagmus D. Downbeat nystagmus E. None of the above

Answer 575

**A. Ocular bobbing** B. Jerk nystagmus C. See-saw nystagmus D. Downbeat nystagmus E. None of the above

Answer 576

.B. The glomerulus is formed by the Golgi cell, the granule cell, and the mossy fiber.

Answer 577

A. The granule cell is the only excitatory cell within the cerebellum

Answer 578

**D. Basket cells end in a rete of terminals around the Purkinje cell**

Answer 579

**C. Purkinje cells synapse with the deep cerebellar nuclei**

Answer 580

A. Blurred vision B. Diaphoresis C. Apnea **D. Hallucinations** E. Sneezing Early signs of cyanide poisoning include general weakness, malaise, early giddiness, inebriation, confusion, headache, vertigo, dizziness, confusion, and hallucinations. Tachypnea and hyperpnea generally precede apnea

Answer 581

A. Manganese B. Zinc C. Iron D. Copper **E. All of the above** ## Footnote All are important in wound healing. Zinc is a mineral that is important for the action of collagenase. Manganese is necessary for the glycosylation of hydroxyproline residues in the formation of collagen. Copper is a cofactor of ceruloplasmin and is involved in the synthesis of oxidative metalloenzymes and elastics. Iron is a vital cofactor for proteins and enzymes involved in energy metabolism, respiration, DNA synthesis, cell cycle arrest, and apoptosis

Answer 582

A. inhibition of DNA synthesis. B. cell membrane destruction. C. cell wall damage. **D. inhibition of protein synthesis.** E. None of the above ## Footnote Aminoglycosides act by inhibiting protein synthesis through irreversible ribosomal attachment. Examples of aminoglycoside antibiotics are amikacin, tobramycin, gentamicin, streptomycin, and neomycin

Answer 583

A. Streptomycin B. Kanamycin C. Neomycin **D. Polymyxin** E. Gentamicin ## Footnote Polymyxin does not cause neuromuscular blockade.

Answer 584

A. The Allcock test is useful. **B. External ventricular drainage following subarachnoid hemorrhage from** this type of aneurysm is an accepted temporizing treatment. C. Proximal ligation is the preferred treatment. D. Vasospasm in this area is unlikely to cause respiratory compromise. E. A lumbar drain is contraindicated in this case. ## Footnote The image represents a vertebral artery aneurysm. The preferred treatment is direct aneurysm clipping of this aneurysm. The Allcock test will test patency of the circle of Willis via carotid occlusion. Vasospasm in this area can cause midbrain and medullary syndrome, including respiratory arrest and neurogenic pulmonary edema. A lumbar arachnoid catheter may also be used to allow CSF drainage

Answer 585

A. The dura needs to be opened at either end well above the lesion. **B. Dilated veins are more likely to be encountered at the rostral end of the mass.** C. Myelotomy is to be done as close to the midline as possible. D. Intracapsular decompression of the tumor is necessary to avoid any traction. E. C-arm guidance for localization may be helpful. ## Footnote When removing an intramedullary spinal cord tumor one is more likely to encounter dilated veins at the caudal end of the mass. The other points are general principles of spinal cord tumor resection. Note that it is useful to seek out the blood supply of the tumor before debulking to keep the fi eld relatively free of blood

Answer 586

**A. sulfatides.** B. galactocerebroside. C. ganglioside. D. long-chain fatty acids. E. None of the above ## Footnote Galactocerebroside accumulates in Krabbe’s disease. Ganglioside accumulates in Tay–Sachs’s and Sandhoff ’s diseases. Long chain fatty acids accumulate in adrenoleukodystroph

Answer 587

A. fl exor response as seen in decerebrate rigidity. B. crossed extensor refl ex. **C. monosynaptic stretch refl ex.** D. supramaximal stimulation of a mixed motor-sensory nerve. E. All of the above ## Footnote The T-refl ex represents the monosynaptic stretch refl ex elicited by tapping a tendon

Answer 588

A. lower pons. B. upper pons. **C. lower midbrain.** D. upper midbrain. E. medulla ## Footnote The trochlear nerve arises at the level of the lower midbrain (inferior colliculus level

Answer 589

A. opsoclonus. B. increased glutamic acid decarboxylase. C. anti–Purkinje cell antibodies. **D. presynaptic acetylcholine receptor disorder.** E. multiple sclerosis ## Footnote The patient likely has Lambert–Eaton myasthenic syndrome (LEMS) with small cell (oat cell) carcinoma. About 60% of those with LEMS have an underlying malignancy, most commonly small cell lung canc

Answer 590

A. 50 mEq **B. 150 mEq** C. 350 mEq D. 500 mEq E. 1000 mEq ## Footnote Total body potassium excess of 100 to 200 mEq is required to produce a rise of 1 mEq/L in serum potassium

Answer 591

A. Lateral cord **B. Ulnar nerve** C. Musculocutaneous nerve D. Median nerve E. Lower subscapular nerve ## Footnote he ulnar nerve has no supply from the C6 root.

Answer 592

B. Cervical roots C2 and C3 innervate this muscle

Answer 593

D. Involved in the phrenic nerve and the brachial plexus.

Answer 594

C. Innervated by the obturator nerve (L2, L3).

Answer 595

D. Innervated by C3, C4 (cervical nerves) and C5 (dorsal scapular nerve which arises from the brachial plexus).

Answer 596

E. Innervated by the pudendal nerve (S2–S4).

Answer 597

B. Innervated by the accessory nerve and C2 roots

Answer 598

**A. Hallucinations while sleeping** B. Convulsions while sleeping C. Daytime hyperalertness D. NREM onset of sleep E. Gelastic seizures ## Footnote Hypnagogic hallucinations are seen with narcolepsy. Hypnagogic or hypnopompic hallucinations are visual, tactile, auditory, or other sensory events, usually brief but occasionally prolonged, that occur at the transition from wakefulness to sleep (hypnagogic) or from sleep to wakefulness (hypnopompic). People with narcolepsy have a reduced number of neurons that produce the protein orexin-A

Answer 599

A. Thiamine B. B6 C. Cobalamine D. Niacin **E. Vitamin A**

Answer 600

**A. Thiamine** B. B6 C. Cobalamine D. Niacin E. Vitamin A

Answer 601

A. Thiamine B. B6 **C. Cobalamine** D. Niacin E. Vitamin A

Answer 602

A. Thiamine **B. B6** C. Cobalamine D. Niacin E. Vitamin A

Answer 603

**A. Type A GABA agonist** B. Type B GABA agonist C. GABA antagonist D. No eff ect on GABA receptors

Answer 604

A. Type A GABA agonist B. Type B GABA agonist **C. GABA antagonist** D. No eff ect on GABA receptors

Answer 605

A. Type A GABA agonist **B. Type B GABA agonist** C. GABA antagonist D. No eff ect on GABA receptors

Answer 606

A. Type A GABA agonist B. Type B GABA agonist **C. GABA antagonist** D. No eff ect on GABA receptors

Answer 607

A. anterior communicating and superior hypophyseal. B. basilar and anterior communicating. C. PICA and superior hypophyseal. D. PICA and basilar. **E. basilar and posterior communicating.** ## Footnote The two aneurysms are a calcifi ed thrombotic basilar artery aneurysm and a posterior communicating artery aneurysm.

Answer 608

A. A common presenting sign is papilledema. B. It arises from the diencephalic recess of the postvellar arch. C. Risk of sudden death is attributable to CSF dynamics or disturbances in hypothalamic-related cardiovascular control. **D. Lumbar puncture is part of the initial workup.** E. The patient may require a shunt postoperatively ## Footnote The lesion presented is a colloid cyst of the third ventricle. A lumbar puncture is contraindicated prior to the placement of a shunt or a ventricular catheter due to the risk of herniation.

Answer 609

A. Phasic changes of amplitude and polarity of ventricular complexes B. Hypokalemia C. Hypomagnesemia **D. Narrowed QT intervals** E. May be predisposed by erythromycin ## Footnote Torsades de pointes presents with prolonged QT intervals.

Answer 610

A. In early ARDS, the hypoxemia is more pronounced and the chest X-ray abnormalities are more evident. B. In early ARDS, the hypoxemia is less pronounced and the chest X-ray abnormalities are more evident. **C. In early ARDS, the hypoxemia is more pronounced and the chest X-ray** abnormalities are less evident. D. In early ARDS, the hypoxemia is less pronounced and the chest X-ray abnormalities are less evident. E. None of the above ## Footnote In early ARDS, the chest X-ray may be unrevealing, whereas the patient may present with a hypoxemia refractory to supplemental oxygen

Answer 611

A. Insulin **B. Alkali therapy** C. Potassium D. Crystalloids E. Phosphate ## Footnote Bicarbonate therapy does not improve outcome in diabetic ketoacidosis, regardless of the severity of the acido

Answer 612

A. metastasis. **B. hemangioblastoma**. C. glioma. D. central nervous system (CNS) lymphoma. E. pilocytic astrocytoma ## Footnote The MRI shows an enhancing mural nodule with an associated cyst. Pathology shows highly vascular tissue and stromal cells characteristic of hemangioblastoma

Answer 613

A. glioblastoma multiforme resection. B. radiation therapy. C. trauma. **D. encephalitis.** E. cerebral atrophy ## Footnote This T2-weighted MRI shows enhancement of the medial temporal lobe, a finding representative of herpes encephalitis

Answer 614

A. deep peroneal nerve. **B. superfi cial peroneal nerve.** C. common peroneal nerve. D. sciatic nerve. E. tibial nerve. ## Footnote The superfi cial peroneal nerve innervates the peroneus longus and brevis, which evert the foot. A lesion of the deep peroneal nerve will aff ect ankle dorsifl exion. A lesion of the common peroneal or sciatic nerves will aff ect both ankle dorsifl exion and foot eversion. A sciatic nerve lesion will also affect foot fl exion and inversion

Answer 615

A. the trunk. B. the branch. **C. the cord.** D. the root. E. None of the above ## Footnote The order of the brachial plexus structures is: root, trunk, division, cord, and branch.

Answer 616

A. Defi nitive clipping, temporary clipping, fi ssure splitting, dissection of M2 branch from dome B. Dissection of M2 branch from dome, fi ssure splitting, temporary clipping, defi nitive clipping **C. Fissure splitting, temporary clipping, dissection of M2 branch from dome, defi nitive clipping** D. Temporary clipping, fi ssure splitting, dissection of M2 branch from dome, defi nitive clipping E. Fissure splitting, dissection of M2 branch from dome, temporary clipping, defi nitive clipping ## Footnote Fissure splitting, temporary clipping, dissection of M2 branch from dome, and defi nitive clipping is the proper order of steps for clipping this difficult aneurysm

Answer 617

A. Overexpression of CDK4 B. Deletion of p53 C. Mutation of retinoblastoma **D. Amplifi cation of K-ras** E. Overexpression of CDK6 ## Footnote Aberrations of genes coding for cell cycle regulatory proteins involved in the control of G1/S phase transition have been found in gliomas and include mutation or deletion of genes like p53, retinoblastoma, cyclic AMP-dependent kinase number 2 (CDKN2) A/B, and amplifi cation or overexpression of CDK4 and CDK6

Answer 618

A. 1p **B. 7** C. 9p D. 19q E. 22 ## Footnote Oligodendrogliomas may exhibit loss of chromosomal regions on 1p and 19q13. Other chromosomal regions that may be lost from oligodendrogliomas are 1p36, 9p, and 22. There may be evidence of increased numbers of chromosome 7

Answer 619

A. Stellate ganglionectomy is used in the treatment of long QT syndrome. B. Anhydrosis occurs with ganglionectomy. C. Each intercostal nerve is connected to the sympathetic trunk by at leastone white ramus and two gray rami. **D. The inferior hypogastric plexus lies in front of the promontory of the sacrum between the two common iliac arteries and is sometimes called the presacral nerve.** E. Sympathetically conveyed stimulus to the sweat glands is transmitted by acetylcholine ## Footnote The superior hypogastric plexus lies in front of the promontory of the sacrum between the two common iliac arteries and is sometimes called the presacral nerve. It then divides into the right and left inferior hypogastric plexuses

Answer 620

A. Cingulate gyrus B. Hippocampus **C. Amygdala** D. Mammillary bodies E. Anterior nucleus of the thalamus

Answer 621

A. Cingulate gyrus B. Hippocampus **C. Amygdala** D. Mammillary bodies E. Anterior nucleus of the thalamus

Answer 622

A. Cingulate gyrus **B. Hippocampus** C. Amygdala D. Mammillary bodies E. Anterior nucleus of the thalamus ## Footnote The circuit of Papez includes the cingulate gyrus, hippocampus, mammillary bodies, and anterior nucleus of the thalamus. The lateral parabrachial nucleus of the amygdala receives inputs from the lateral olfactory tract, pyriform cortex, hypothalamus, paraventricular thalamus, and solitary tract nucleus. The medial septal nucleus projects to the fi mbria to the hippocampus

Answer 623

A. Amyotrophic lateral sclerosis (ALS) B. Huntington’s disease C. Acute respiratory distress syndrome **D. AIDS** E. Multiple sclerosi

Answer 624

A. Congestive heart failure B. Pulmonary hypertension C. Renal failure **D. Microcephaly** E. Subarachnoid hemorrhage

Answer 625

**A. The most common location is cervicothoracic.** B. The presence of a malignancy is a predisposing condition. C. There is increased incidence with epidural anesthesia. D. The incidence is 1:10,000 in the United States. E. There is increased incidence with drug abuse

Answer 626

A. antibiotic therapy. **B. diuretics.** C. secretory diarrhea. D. diabetes mellitus. E. dilantin therapy. ## Footnote Urinary magnesium loss is most prominent with loop diuretics

Answer 627

A. Jugular B. Nodose **C. Pterygopalatine** D. Ciliary E. Superior cervical ## Footnote The superior salivatory nucleus sends axons via the nervus intermedius (VII) to the greater superfi cial petrosal nerve and then to the pterygopalatine ganglion

Answer 628

A. Jugular B. Nodose C. Pterygopalatine **D. Ciliary** E. Superior cervical ## Footnote The oculomotor nerve (III) carries parasympathetics from Edinger–Westphal’s nucleus to the ciliary ganglion

Answer 629

**A. Jugular** B. Nodose C. Pterygopalatine D. Ciliary E. Superior cervical ## Footnote Arnold’s nerve is a branch of the vagus nerve (X) supplying sensation to the dura of the posterior fossa

Answer 630

A. Jugular B. Nodose C. Pterygopalatine D. Ciliary **E. Superior cervical** ## Footnote The deep petrosal nerve carries sympathetic fi bers from the internal carotid artery from the superior cervical ganglion

Answer 631

**A. Loss of sensation to the outer ear** B. Loss of taste on the tongue surface C. Loss of salivatory secretion from a gland D. Weakness of the pharynx E. Strength of facial muscles ## Footnote Both nerves contain sensory inputs from the outer ear. The glossopharyngeal nerve controls elevation of the pharynx, whereas the facial nerve has no actions on pharyngeal mus

Answer 632

A. dopamine. **B. dobutamine.** C. neosinephrine. D. epinephrine. E. isoproterenol ## Footnote Dobutamine is an adrenergic agent that does not cause peripheral vasoconstriction.

Answer 633

A. cyanide. **B. thiocyanate.** C. nitric oxide. D. thiosulfate. E. vitamin B12 ## Footnote Thiocyanate is cleared by the kidneys and its accumulation with the use of nitroprusside may cause a toxic syndrome

Answer 634

B. Single punched out lesion without sclerotic edges is typical

Answer 635

B. Eosinophilic granuloma may be a monostotic form of Langerhans cell histiocytosis.

Answer 636

C. In Paget’s disease, one may observe bony destruction (early) and sclerosis (late).

Answer 637

A. Albright’s syndrome is characterized by unilateral fi brous dysplasia, pigmented skin lesions, and precocious puberty.

Answer 638

D. Epidermoid has characteristic scalloped edges

Answer 639

**A. Pneumocystis carinii pneumonia**. B. cytomegalovirus infections. C. toxoplasmosis. D. AIDS encephalitis. E. hydrocephalus. ## Footnote Pneumocystis carinii pneumonia is the most common cause of ICU admission in HIV-positive patients. It is usually treated with trimethoprim-sulfamethoxazole. Toxoplasma is the most common intracranial infection in HIV-positive patient

Answer 640

A. 9%. B. 0.9%. **C. 0.09%.** D. 0.009%. E. 0.0009% ## Footnote There are 9 cases of transmission for every 10,000 exposures. It is advisable to wear two pairs of gloves at surgery and to replace the top pair every 90 minutes of arduous surgery

Answer 641

A. Chordoma B. Epidermoid C. Basilar tip aneurysm **D. Arachnoid cyst** E. Low-grade glioma ## Footnote The lesion most likely represents a lobulated arachnoid cyst. An aneurysm would not display such septations.

Answer 642

A. Golgi organelle B. Endoplasmic reticulum C. Both A and B **D. None of the above**

Answer 643

**A. Golgi organelle** B. Endoplasmic reticulum C. Both A and B D. None of the above ## Footnote The Golgi organelle possesses enzymes that are important in sugar and lipid chemistry of the eukaryotic cell.

Answer 644

A. Golgi organelle **B. Endoplasmic reticulum** C. Both A and B D. None of the above ## Footnote The endoplasmic reticulum is important in drug detoxifi cation; for example, adding hydroxyl groups to a lipid soluble–type compound makes it more water soluble and thus easier to remove from the

Answer 645

A. Golgi organelle **B. Endoplasmic reticulum** C. Both A and B D. None of the above ## Footnote Glycogen formation and breakdown occur in the endoplasmic reticulum; this is particularly important in the liver. Glycogen, a polymer of glucose-1-phosphate, represents a quick source of energy.

Answer 646

A. Golgi organelle B. Endoplasmic reticulum **C. Both A and B** D. None of the above ## Footnote Both the Golgi membranes closest to the nucleus (forming face) and the endoplasmic reticulum have a lamellar or tube-like membranous system. The Golgi membranes away from the nucleus (maturing face) are much more like plasma or organelle membranes

Answer 647

A. Accumulates in neurons of the substantia nigra B. Found in the locus ceruleus **C. Made by tyrosinase** D. Is a cathecholamine waste product E. Chelates metal ions such as aluminum and iron ## Footnote True melanin is made by tyrosinase. Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. Neuromelanin is biosynthesized from L-dopa by tyrosine hydroxylase and aromatic acid decarboxylase.

Answer 648

**A. Nucleus accumbens** B. Pyriform cortex C. Solitary tract nucleus D. Locus ceruleus E. Prefrontal cortex ## Footnote he amygdala sends eff erents to the nucleus accumbens via the amygdalostriate fi bers. All others are aff erent sources to the amygdala.

Answer 649

A. Hypercapnia B. Acalculous cholecystitis C. Impaired oxygenation **D. Calculous cholecystitis** E. Increased incidence of infection ## Footnote Total parenteral nutrition has been known to cause hypercapnia due to excessive carbohydrates promoting carbon dioxide retention, impaired oxygenation due to fatty acid damage to pulmonary capillaries, and acalculous cholecystitis due to bile stasis secondary to absence of lipids in the proximal small bowel

Answer 650

**A. May have elevated carcinoembryonic antigen (CEA) levels** B. Associated with Schiller–Duval bodies C. Derived from extraembryonic tissue D. Ingestion of food with fecal contamination E. Multiple sclerosis ## Footnote This scan shows a teratoma, which is associated with elevation of CEA levels

Answer 651

A. Anti-Yo antibodies **B. Anti-Hu antibodies** C. Anti-Ri antibodies D. Antibodies to presynaptic voltage-gated receptors E. None of the above ## Footnote Paraneoplastic sensory neuropathy with anti-Hu antibodies is associated with limbic encephalitis (as seen on this MRI scan), seizures, epilepsia partialis continua, cerebellar ataxia, autonomic instability, myelitis with patchy weakness, and brainstem encephalitis.

Answer 652

**A. 40-year-old man with chronic encephalitis and Argyll Robertson pupils** B. 15-year-old hyperglycemic with severe lower extremity weakness C. 55-year-old man with spastic gait, weakness, and fasciculation in all extremities D. 4-year-old boy with bilateral symmetric proximal limb weakness E. 60-year-old female with spondylolisthesis at L5–S1

Answer 653

A. Respiratory acidosis B. Respiratory alkalosis **C. Both** D. Neither

Answer 654

A. Respiratory acidosis **B. Respiratory alkalosis** C. Both D. Neither

Answer 655

A. Respiratory acidosis **B. Respiratory alkalosis** C. Both D. Neither

Answer 656

**A. Respiratory acidosis** B. Respiratory alkalosis C. Both D. Neither ## Footnote Massive pulmonary embolism can result in signifi cant increased dead space and respiratory acidosis; on the other hand, smaller pulmonary embolisms can present with hyperventilation and hence respiratory alkalosis. Liver cirrhosis may also cause hyperventilation. Aminoglycosides can be presynaptic at the neuromuscular junction, causing respiratory acidosis.

Answer 657

A. Water diff usion is hindered anteriorly by the presence of a large tumor. **B. Connections between frontal and occipital lobe are impaired on the right side.** C. There are intersecting white matter tracts between the splenium and the fronto-occipital tracts. D. Tractography gives information about the direction of fl ow. E. Bundles of axons provide a barrier to perpendicular diff usion and a path for parallel diff usion along the orientation of the fi bers ## Footnote Tractography is a procedure to demonstrate the neural tracts. It uses special techniques of magnetic resonance imaging (MRI), and computer postprocessing. Information about direction of fl ow is provided by tractography but not about connections between diff erent structures in the brain

Answer 658

**A. It is associated with dermal sinus tract.** B. It secretes histamine. C. On histopathology, one may see densely packed elongated spindle cells in interlocking fascicles with a tendency toward palisading. D. All of the above are true. E. None of the above are true. ## Footnote The scan shows an atypical dermoid cyst. Dermoid cysts can contain fat which gives them high signal intensity on T1-weighted sequences. A congenital dermal sinus tract can be associated with a dermoid cyst. Choice B is associated with paraganglioma. Choice C is representative of Antoni A pattern in acoustic neuromas

Answer 659

A. Abnormality in protein merlin B. Posterior capsular lens opacities **C. Intertriginous freckling** D. Pigmented area of skin with excess hair E. May be associated with an autosomal disorder located on chromosome 22 ## Footnote The MRI scan shows bilateral acoustic neuromas, pathognomonic of neurofibromatosis type 2. Intertriginous freckling is a feature of neurofi bromatosis type 1.

Answer 660

A. Amphotericin B B. Lithium C. Toluene **D. Carbonic anhydrase inhibitors** E. Cyclamate ## Footnote Carbonic anhydrase inhibitors (e.g., acetazolamide) can cause proximal renal tubular acidosis.

Answer 661

A. Hydrocortisone sodium succinate (Solucortef) for glucocorticoid emergencies B. Fludrocortisone (Florinef) for mineralocorticoid emergencies **C. Methylprednisolone (Solumedrol) for glucocorticoid emergencies** D. Cortisone acetate for glucocorticoid emergencies E. Intravenous fl uids ## Footnote Methylprednisolone is not recommended in the treatment of emergent Addisonian crisis. Long-term use of methylprednisolone can cause Addisonian crisis if stopped abruptly and not tapered.

Answer 662

A. furosemide. B. phenytoin. C. lithium. **D. All of the above** E. None of the above ## Footnote All three medications have been shown to help in the treatment of syndrome of inappropriate antidiuretic hormone (SIADH), with variable side-eff ect patterns

Answer 663

**A. B and O plasma types** B. B and AB plasma types C. B plasma type only D. All of the above E. None of the above ## Footnote Plasma types B and O can be safely transfused in a patient with blood type B because both of these plasma types do not contain antibodies against B type blood.

Answer 664

A. Increased arteriolar tone B. Increased in peripheral vascular resistance C. Cool molten skin D. Hypertension **E. Bradycardia** ## Footnote Neurogenic shock is characterized by dilatation of arterioles and venules and decreased peripheral vascular resistance. It also presents with warm, dry skin, bradycardia, and hypotension

Answer 665

**A. urinary tract infection.** B. pneumonia. C. wound infection. D. gastrointestinal infection. E. pressure ulcers. ## Footnote The urinary system is the most commonly involved in patients with gram-negative septicemia, followed by the respiratory system

Answer 666

A. Latex agglutination test B. Tissue culture assay for cytotoxin **C. Stool culture** D. Stool microscopy E. Polymerase chain reaction (PCR) analysis ## Footnote Stool culture has a sensitivity of > 90% in diagnosing C. diffi cile enterocolitis. Both latex agglutination and tissue culture assay for cytotoxin have a sensitivity of ~ 70%. Stool microscopy is not used to diagnose this co

Answer 667

A. Isoflurane B. Enflurane C. Thiopental **D. Halothane** ## Footnote Halothane increases cerebral blood fl ow the most followed by enfl urane and isofurane.

Answer 668

A. Isoflurane B. Enflurane **C. Thiopental** D. Halothane ## Footnote Thiopental decreases intracranial pressure. The other listed agents will increase intracranial pressure.

Answer 669

**A. Isoflurane** B. Enflurane C. Thiopental D. Halothane ## Footnote Isofurane has been shown to cause tachycardia transiently in children

Answer 670

A. Isoflurane **B. Enflurane** C. Thiopental D. Halothane ## Footnote Enfurane increases systemic vascular resistance. Isofurane will decrease it

Answer 671

A. Neurofi bromatosis type 1 (NF1) B. Neurofi bromatosis type 2 (NF2) **C. Both A and B** D. None of the above ## Footnote C. Both NF1 and NF2 have autosomal dominant patterns of inheritance

Answer 672

A. Neurofi bromatosis type 1 (NF1) B. Neurofi bromatosis type 2 (NF2) C. Both A and B D**. None of the above**

Answer 673

**A. Neurofi bromatosis type 1 (NF1)** B. Neurofi bromatosis type 2 (NF2) C. Both A and B D. None of the above

Answer 674

A. Neurofi bromatosis type 1 (NF1) B. Neurofi bromatosis type 2 (NF2) C. Both A and B **D. None of the above**

Answer 675

A. The neck of the aneurysm is unobstructed. B. The neck of the aneurysm is obstructed by the dome. C. The neck of the aneurysm is obstructed by the optic nerve. D. The neck of the aneurysm is obstructed by the carotid artery. **E. The neck of the aneurysm is obstructed by the anterior clinoid process**

Answer 676

A. Superior cerebellar artery, abducens nerve B. Anterior inferior cerebellar artery, trochlear nerve **C. Superior cerebellar artery, trochlear nerve **D. Anterior inferior cerebellar artery, abducens nerve E. Superior cerebellar artery, oculomotor nerve

Answer 677

**A. Supracerebellar infratentorial approach for cyst resection** B. Midline frontal approach for cyst resection C. Third ventriculostomy D. Midline frontal approach for cyst decompression E. Endoscopic cyst resection

Answer 678

A. Meperidine B. Thyroid hormones C. Fluconazole **D. Papaverine**

Answer 679

A. Meperidine B. Thyroid hormones **C. Fluconazole** D. Papaverine

Answer 680

A. Meperidine **B. Thyroid hormones** C. Fluconazole D. Papaverine

Answer 681

A. Meperidine B. Thyroid hormones **C. Fluconazole** D. Papaverine

Answer 682

**A. Meperidine** B. Thyroid hormones C. Fluconazole D. Papaverine ## Footnote Papaverine inhibits antiparkinsonian eff ect of levodopa. Fluconazole increases serum phenytoin and decreases warfarin metabolism. Thyroid hormones enhance clotting factor catabolism. Meperidine may cause hypertension, rigidity, and excitation when used with monoamine oxidase inhibitors

Answer 683

A. Epinephrine B. Isoflurane C. Halothane **D. Thiopental** E. All of the above

Answer 684

A. Lung carcinoma B. Breast carcinoma **C. Colon carcinoma** D. Renal cell carcinoma E. Prostate carcinoma

Answer 685

A. Brachiocephalic artery **B. Axillary artery** C. Subcalvian artery D. Brachial artery E. Internal carotid artery ## Footnote The lateral, medial, and posterior cords carry their names in relation to the second and third segments of the axillary artery

Answer 686

A. Traumatic B. Degenerative C**. Isthmic** D. Pathological E. Dysplastic ## Footnote This type of spondylolisthesis is caused by a defect in the pars interarticularis, occurs in 90% of cases at L5–S1, and is usually bilateral and more common in males

Answer 687

A. Homonymous hemianopia B. Upper homonymous quadrantanopia C. Bilateral central scotomas **D. Monocular loss of vision with contralateral upper outer quadrantanopia** E. Lower homonymous quadrantanopia

Answer 688

**A. Homonymous hemianopia** B. Upper homonymous quadrantanopia C. Bilateral central scotomas D. Monocular loss of vision with contralateral upper outer quadrantanopia E. Lower homonymous quadrantanopia

Answer 689

**A. Homonymous hemianopia** B. Upper homonymous quadrantanopia C. Bilateral central scotomas D. Monocular loss of vision with contralateral upper outer quadrantanopia E. Lower homonymous quadrantanopia

Answer 690

A. Homonymous hemianopia B. Upper homonymous quadrantanopia **C. Bilateral central scotomas** D. Monocular loss of vision with contralateral upper outer quadrantanopia E. Lower homonymous quadrantanopia

Answer 691

A. Homonymous hemianopia **B. Upper homonymous quadrantanopia** C. Bilateral central scotomas D. Monocular loss of vision with contralateral upper outer quadrantanopia E. Lower homonymous quadrantanopia

Answer 692

A. Homonymous hemianopia B. Upper homonymous quadrantanopia C. Bilateral central scotomas D. Monocular loss of vision with contralateral upper outer quadrantanopia **E. Lower homonymous quadrantanopia**

Answer 693

A. Struthers ligament **B. Arcade of Struthers** C. Arcade of Frohse D. Guyon’s canal

Answer 694

A. Struthers ligament B. Arcade of Struthers **C. Arcade of Frohse** D. Guyon’s canal

Answer 695

**A. Struthers ligament** B. Arcade of Struthers C. Arcade of Frohse D. Guyon’s canal

Answer 696

A. Reservoir sign B**. Early morning headache** C. Meningitis D. Visual defi cits E. Sinus congestion

Answer 697

A. Radicular pain **B. Scoliosis** C. Weakness D. Atrophy E. None of the above ## Footnote Scoliosis occurs in 66%, whereas radicular pain occurs in 50% of patients

Answer 698

A. Radicular pain B. Scoliosis **C. Weakness** D. Atrophy E. Cardiac ischemia ## Footnote Weakness occurs in 51%, whereas radicular pain occurs in 44% and scoliosis in 36% of patients.

Answer 699

A. 1, 2, and 3 B. 1 and 3 C. 2 and 4 **D. 1, 2, 3, and 4** E. 2 and 3

Answer 700

A. It is caused by frequent repetitive motion at the wrist. B. Pain and tenderness occurs in the wrist near the thumb. C. The Finkelstein test is positive. **D. Nerve conduction velocities are decreased.** E. There is diffi culty with gripping. ## Footnote De Quervain’s syndrome is characterized by tenosynovitis of the abductor pollicis longus and extensor pollicis brevis muscles. The nerve conduction velocities are typically normal

Answer 701

**B** ## Footnote The roof of the fourth ventricle contains both the superior and inferior medullary veli. The fl oor of the fourth ventricle is formed by the rhomboid fossa, which contains the facial colliculus and hypoglossal trigone

Answer 702

A. Surgical evacuation B. Systemic antibiotics **C. Head wrapping** D. Radiation therapy E. VP shunt

Answer 703

A. Basal plate **B. Notochord** C. Neural crest cells D. Somites E. Endoderm

Answer 704

A. Cheyne–Stokes respiration B. Apneustic respiration **C. Ataxic respiration** D. Central neurogenic hyperventilation

Answer 705

A. Cheyne–Stokes respiration B. Apneustic respiration C. Ataxic respiration **D. Central neurogenic hyperventilation**

Answer 706

A. Cheyne–Stokes respiration **B. Apneustic respiration** C. Ataxic respiration D. Central neurogenic hyperventilation

Answer 707

**A. Cheyne–Stokes respiration** B. Apneustic respiration C. Ataxic respiration D. Central neurogenic hyperventilation

Answer 708

A. Middle cerebellar peduncle **B. Inferior cerebellar peduncle** C. Nodulus D. Flocculus E. None of the above

Answer 709

**A. Middle cerebellar peduncle** B. Inferior cerebellar peduncle C. Nodulus D. Flocculus E. None of the above

Answer 710

A. It connects the basilar artery between the superior cerebellar and the anterior inferior cerebellar arteries by passing through the petrous bone. **B. It connects the basilar artery by passing through the internal auditory meatus**. C. It is present in 0.1% of the population. D. There is increased frequency of arteriovenous malformations. E. It is the second most common persistent fetal circulation.

Answer 711

A. 75% B. 50% C. 25% D. 2% **E. 0.3%** ## Footnote The overall rate of HIV transmission from a single percutaneous exposure to HIV-infected blood with high viral load is of the order of 0.3%. Postexposure prophylaxis (PEP) has been shown in one study to reduce this rate by 80%. It is important to check viral loads of patients prior to elective surgery to keep operating room staff and surgeons safe.

Answer 712

A. 75% B. 50% C. 25% **D. 2%** E. 0.3% ## Footnote Epidemiological studies of health care workers exposed to hepatitis C virus through a needlestick or other percutaneous injury have found that the incidence of infection averages 1.8% per injury.

Answer 713

A. 75% B. 50% C. 25% **D. 2%** E. 0.3% ## Footnote The risk of acquiring hepatitis B from a needlestick when the source was hepatitis B antigen-positive ranges from approximately 2 to 40%, depending on the source’s level of viremia.

Answer 714

A. tentorial subdural hemorrhage. B. subarachnoid hemorrhage. C. normal CT scan. **D. dural sinus thrombosis.** E. arteriovenous fi stula

Answer 715

**A. There is an autosomal recessive inheritance pattern.** B. In 20% of cases there is no hyperthermia accompanying the muscle rigidity. C. It may be associated with autonomic instability. D. It may be caused by muscle relaxants. E. A mutation in the ryanodine receptor is related to malignant hyperthermia (MH). ## Footnote Malignant hyperthermia has an autosomal dominant inheritance pattern. It may be caused by halothane or succinylcholine. Body temperature increase is about 1°C every 5 minutes. It is treated with dantrolene and discontinuation of the anesthetic

Answer 716

A. Cerebral aneurysm B. Arteriovenous malformation C. Endocrinopathy **D. Venous angioma** E. Progressive supranuclear palsy ## Footnote The scan shows a cavernous angioma occurring at the thalamocaudate recess. These lesions may be associated with venous angioma

Answer 717

**A. Type 1 Modic changes** B. Type 2 Modic changes C. Yellow marrow replacement D. Hypovascularization of the end plates E. None of the above ## Footnote Type 1 Modic changes show decreased intensity on T1-weighted images and increased intensity on T2-weighted images. Type 2 Modic changes show increased intensity on T1-weighted images and isointense signal intensity on T2-weighted images. Histopathology on type 1 changes demonstrates disruption and fi ssuring of the end plates and vascularized fi brous tissue. On type 2 changes, yellow marrow replacement is seen. Type 1 changes may convert to type 2 after a few years. There appears to be a spectrum of vertebral body marrow changes associated with degenerative disk disease.

Answer 718

A. Ataxia B. Ipsilateral hearing defi cits C. Contralateral temperature sensation loss **D. Lateral rectus palsy** E. Balance problems ## Footnote The lesion represents a syrinx at the level of the inferior cerebellar peduncle. The abducens nerve arises at a higher level and is less likely to be aff ected. The anterolateral system courses ventral to the lesion and may be aff ected. The vestibulocochlear nucleus is also located at this level

Answer 719

**A. Ketamine** B. Thiopental C. Halothane D. Enflurane E. Isoflurane ## Footnote Ketamine raises systemic arterial blood pressure but not necessarily the perfusion in hypovolemic states. In hypotensive states of short duration from endotoxin treatment, it improved the hemodynamics by augmenting the perfusion and the systemic pressure

Answer 720

A. Froin’s syndrome B. Positive Queckenstedt’s sign **C. Male predominance with peak age in mid-40s** D. Cellular type E. Neoplastic disease ## Footnote The scans show a typical intramedullary ependymoma with blockage of CSF fl ow, which is associated with Froin’s syndrome (clotting and xanthochromia in the CSF) and Queckenstedt’s sign, which is failure of jugular vein compression to increase CSF. The cervical type of intramedullary ependymoma is usually of the cellular type, more frequent in females in the mid-40s

Answer 721

A. Syringobulbia **B. Elevated serum angiotensin-converting enzyme** C. Aqueductal stenosis D. Hallervorden–Spatz disease E. Subdural hematoma ## Footnote The MRI set demonstrates basilar meningitis with a trapped fourth ventricle and foramina of Luschka which occurs in sarcoidosis. Elevated angiotensin-converting enzyme levels is also a feature of this disease.

Answer 722

A. Proximal renal tubular function **B. Distal renal tubular function** C. Kidney glomerular function D. None of the above

Answer 723

**A. Proximal renal tubular function** B. Distal renal tubular function C. Kidney glomerular function D. None of the above

Answer 724

A. Proximal renal tubular function **B. Distal renal tubular function** C. Kidney glomerular function D. None of the above

Answer 725

A. Proximal renal tubular function B. Distal renal tubular function **C. Kidney glomerular function** D. None of the above ## Footnote The proximal tubule plays a role in secreting organic acids and reabsorbing Na+ , water, glucose, bicarbonate, amino acids, and phosphate. The distal tubule’s role involves secretion of H+ and K+ and reabsorption of Na+ and Cl. The glomerular fi ltration rate is at its peak in young adulthood, at about 120 mL/min

Answer 726

**A. The most signifi cant factor associated with recurrence is extent of resection.** B. A factor associated with recurrence is histology. C. MIB-1 LI >7% is associated with a low likelihood of recurrence. D. Malignant transformation to carcinoma frequently occurs. E. Recurrence is dependent on the presence of intracytoplasmic inclusions. ## Footnote The images show craniopharyngioma. The most signifi cant factor associated with recurrence is extent of resection. Histology type is not correlated with frequency of recurrence. MIB-1 LI > 7% is associated with a higher likelihood of recurrence. Malignant transformation to carcinoma exceptionally occurs.

Answer 727

**A. Central neurocytoma** B. Oligodendroglioma C. Ependymoma D. Endodermal sinus tumor E. Yolk sac tumor ## Footnote Central neurocytoma appears like oligodendroglioma histologically but is positive for synaptophysin on immunohistochemistry.

Answer 728

**A. Operculum** B. Sylvian fi ssure C. Precentral sulcus D. Rolandic fi ssure E. None of the above ## Footnote The parietal operculum is caudal to the inferior frontal gyrus. Directly inferior to the inferior frontal gyrus is the sylvian fissure

Answer 729

A. Nitroglycerine binds the surface of endothelial cells. B. Nitroglycerine undergoes two chemical reductions to form nitric oxide. **C. Nitric oxide promotes the formation of cyclic guanosine triphosphate.** D. Nitric oxide moves out of the endothelial cell into adjacent smooth muscle cell. E. Nitric oxide increases cAMP in smooth muscle cells

Answer 730

A. 1% per year B. 2% per year C. 4% per year **D. 13% per year** E. 26% per year

Answer 731

A. 1% per year B. 2% per year C. 4% per year **D. 13% per year** E. 26% per year

Answer 732

A. 1% per year B. 2% per year **C. 4% per year** D. 13% per year E. 26% per year

Answer 733

**A. Amphotericin** B. Angiotensin-converting enzyme inhibitors C. Aspirin D. Cyclosporin E. Heparin

Answer 734

A. 2 hours B. 2 days **C. 12 days** D. 22 days E. 32 days ## Footnote Intracellular methemoglobin appears as hyperintense on T1 and hypointense on T2, and is usually present from 3 days to 2 weeks after a hemorrhage. Extracellular methemoglobin appears after 2 weeks and is hyperintense on T1 and T2. The images show hyperintensity on T1 and iso- to hypointensity on T2, consistent with intracellular methemoglobin toward the end of 2 weeks following the hemorrhage.

Answer 735

A. Ethanol B. Acetone **C. Methanol** D. Ethylene glycol (antifreeze) E. Acethaldehyde

Answer 736

A. Ethanol B. Acetone C. Methanol **D. Ethylene glycol (antifreeze)** E. Acethaldehyde ## Footnote Ethanol has a molecular weight of 46 and is lethal at levels > 350 mg/dL (least lethal). Methanol has the lowest molecular weight (32) and is the least lethal out of the three remaining substances (80 mg/dL needed for lethality). Ethylene glycol has the highest molecular weight (61) and is the most lethal (only 21 mg/dL needed to cause death)

Answer 737

A. whole blood. B. fi brinogen. C. platelets. D. packed red blood cells. **E. cryoprecipitate**

Answer 738

A. Ipsilateral Horner’s syndrome B. Downbeat nystagmus C. Loss of abdominal cutaneous refl ex **D. Neurogenic bladder** E. Extremity weakness ## Footnote The scan shows a foramen magnum tumor. All the stated clinical fi ndings are associated with this tumor location; however, neurogenic bladder tends to occur very late

Answer 739

A. Saddle bilateral sensory defi cit B. Symmetric motor loss C. Loss of ankle jerk **D. Autonomic symptoms that occur late** E. Urinary retention and atonic anal sphincter that cause overfl ow urinary incontinence and fecal incontinence

Answer 740

**A. Sensory dissociation** B. Asymmetric motor loss C. Late autonomic symptoms D. Absence of ankle jerk and knee jerk E. Numbness that tends to be more localized to saddle area ## Footnote There is no sensory dissociation. Red fl ags for cauda equina syndrome are erection diffi culty, extreme back pain, and groin numbness. An MRI scan taken in a lying down position may not display the stenosis so a standing MRI scan, if available, is necessary. These patients should be sent to an emergency room at once for stat MRI. In the setting of groin numbness only with back pain, urodynamics and Foley catheter may not be absolutely necessary. One should not delay care of these patients to the point in time where urodynamics become necessary. If these patients present in the emergency room, they should not be sent home to follow up electively, they should be decompressed and stabilized on that hospital admission

Answer 741

A. Brachiocephalic artery B. Right subclavian artery C. Left subclavian artery D. Right carotid artery **E. Left carotid artery** ## Footnote The aorta gives off , from proximal to distal, the brachiocephalic trunk, left common carotid, and left subclavian arteries

Answer 742

A. Convergence defi cit **B. Adduction defi cit** C. Horizontal gaze palsy D. Vertical gaze palsy E. Parinaud’s syndrome ## Footnote With bilateral internuclear ophthalmoplegia there is an adduction defi cit in both eyes. This is observed in bilateral lesions of the medial longitudinal fasciculus.

Answer 743

**A. Acetylcholine** B. Noradrenaline C. Dopamine D. GABA E. Glutamate

Answer 744

A. Acetylcholine **B. Noradrenaline** C. Dopamine D. GABA E. Glutamate

Answer 745

A. Acetylcholine **B. Noradrenaline** C. Dopamine D. GABA E. Glutamate

Answer 746

A. 1, 2, and 3 are true. B. 1 and 3 are true. **C. 2 and 4 are true.** D. Only 4 is true. E. All of the above are true.

Answer 747

A. Regional hypotension B. CBF below critical level **C. Atrial fi brillation** D. Cardiac arrest E. Anaphylaxis

Answer 748

A. Bernasconi’s artery B. Persistent stapedial artery C. Heubner’s artery **D. McConnell’s artery** E. Vidian artery

Answer 749

A. Thirty to fi fty percent of patients are febrile. B. Spontaneous fusion of vertebral bodies may occur. C. Haemophilus infl uenzae may be a causative organism in juvenile cases. **D. Radionuclide scans have a relatively low sensitivity.** E. There is increased incidence with intravenous drug abuse.

Answer 750

**A. Increased neuronal density** B. Increased metabolism C. Increased excitatory neurotransmission D. Necrosis E. None of the above ## Footnote N-acetylaspartate (NAA), found in neurons and axons, is used as a neuronal marker. A reduction in the NAA signal refl ects neuronal loss or injury, as seen in many brain pathologies including neurodegenerative diseases. NAA peaks typically represent increased neuronal density. Moderately increased choline peaks and reduced NAA signal intensities indicate low-grade gliomas; highgrade tumors are characterized by distinctly higher choline peaks and even lower NAA signals, and the presence of lipid signals indicates tissue necrosis

Answer 751

A. Mucor **B. Aspergillus** C. Coccidioides D. E. histolytica E. Virus ## Footnote Aspergillus has a predilection for the basal ganglia in some cases. It tends to invade blood vessels, cause hemorrhagic infarcts, and may cause formation of paranasal sinus mycetoma. Coccidioides can cause meningitis and caseating granulomas. The diagnosis of early cerebral infarction in a patient considered at risk for invasive aspergillosis, even without overt pulmonary disease, is an indication to institute aggressive antifungal therapy

Answer 752

A. Perivascular invasion B. Hemorrhagic infarcts C. Paranasal sinus mycetoma **D. Caseating granulomas** E. Increased prevalence with the use of chemotherapy and corticosteroids

Answer 753

A. Intravenous antibiotics B. Surgical resection **C. Systemic chemotherapy and whole-brain radiation** D. Ommaya reservoir placement and intrathecal chemotherapy E. Ventriculoperitoneal shunt ## Footnote The MRI scan demonstrates leptomeningeal gliomatosis associated with a high-grade glioma in the left occipital area. The best therapeutic option, given the diff use nature of the disease is, initially, chemotherapy and radiation

Answer 754

A. Stapedius B. Tensor veli palatini **C. Stylopharyngeus** D. Posterior belly of digastric E. None of the above

Answer 755

A. A B. B C.C **D.D**

Answer 756

A. A B. B C.C **D.D**

Answer 757

A. A **B. B** C.C D.D

Answer 758

A. A B. B **C.C** D.D ## Footnote Functional residual capacity (D) does not change during exercise and is usually 2.4L. It is the sum or residual volume (C) and expiratory reserve volume (ERV), or the diff erence between vital capacity (B) and ERV. Vital capacity (VC) is usually around 4.4 to 5 L and is measured by having the patient inhale profoundly and exhale fully into a spirometer. Residual volume cannot be measured directly and needs to be calculated as a percentage of exhaled versus inhaled 10% helium-containing solution

Answer 759

A. Elevated N-acetylaspartate (NAA) peak and normal choline (Chol) and creatine (Cr) peaks B. Elevated Cr peak and decreased Chol and NAA peaks **C. Increased Chol:Cr ratio and decreased NAA peak** D. Increased Cr:Chol ratio and decreased NAA peak E. All of the above

Answer 760

A. Increased astrocytic density at point 3 as compared with point 1 **B. Presence of tumor cells at point 3** C. Presence of necrosis at point 3 D. Increased metabolism at point 3 E. All of the above ## Footnote Point 3 on the MR spectroscopy represents an area of tumor (glioma), which shows an elevated Chol:Cr ratio and a decreased NAA peak. Other changes seen in tumors may be decreased Chol and elevated NAA

Answer 761

A. Oxygen delivery **B. Oxygen uptake** C. Oxygen extraction ratio D. Oxygen content E. None of the above ## Footnote The formula represents oxygen uptake

Answer 762

A. Cc O2 − Ca O2 / Cv O2 − Ca O2 B. (Cc O2 − Cv O2)/(Cc O2 − Ca O2) C. Cc O2 − Ca O2/Cc O2 − Cv O2 **D. (Cc O2 − Ca O2)/(Cc O2 − Cv O2)** E. (Cc O2 − Ca O2)/(Cv O2 − Ca O2)

Answer 763

**A. Q = Pπr4/8VL** B. Q = 8PL/Vπr4 C. Q = Vπr4/8PL D. Q = 8Vπr4/PL E. None of the above

Answer 764

A. immediately in the ER. B. before a CT scan. **C. in the operating room**. D. before antibiotics are given. E. after the patient has been stabilized ## Footnote If the pencil is pulled from his eye, there should be adequate measures to stop bleeding and irrigate the wound. This can be properly performed only in the operating room. This patient should be managed with antiepileptic medication, broad-spectrum antibiotics, CT scan, immediate open surgical debridement, and follow-up MRI in about a week

Answer 765

A. Single-level anterior cervical diskectomy and fusion (ACDF) B. Two-level ACDF C. Posterior decompression **D. Cervical corpectomy and fusion** E. Three-level ACDF

Neurosurgery Practice QnA Flashcards

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