NEUROLOGY Flashcards

Question

A 45 year old male consulted due to recurrent headaches. On history, he had 2 previous hospital admissions due to intracerebral hemorrhages, as confirmed through plain Cranial CT scan. The last episode of intracerebral hemorrhage occurred 1 month prior to consult. What is the recommended cranial imaging technique for this patient? a. Repeat Cranial CT Scan b. Cranial MRI c. 4 vessel angiogram d. Transcranial doppler

Answer 1

Table 416-1 Guidelines for Use of CT, Ultrasound, and MRI. HPIM page 3030 - 3033 In patients with subacute hemorrhage, MRI is the imaging of choice because the MR sequences may detect micro- hemorrhages, and determine the etiology of the bleed (eg. Cavernous malformations, amyloid, hemorrhagic metastased – see Fig 416-5). CT scan is recommended for ACUTE Intracerebral hemorrhage as it can be done faster than MRI, and is reliable in detecting acute blood. 4 vessel angiogram is indicated for patients suspected to have vascular malformations and aneurysms. Transcranial doppler is used to monitor vasospasm and cerebral bloodflow. The correct answer is: Cranial MRI

Answer 2

This patient who has a 1cm midline shift on CT scan and is starting to have decreased sensorium should be started on osmotic agents such as Mannitol or hypertonic saline. Maintaining a MAP of 110-130 to facilitate permissive hypertension is done in the management of cerebral iINFARCTION. Recent trials in BP management for hypertensive ICH (INTERACT 2 AND ATTACH 2) showed that lowering the SBP to 140-180mmHg is likely safe and possibly beneficial. Patients with ICH are placed in moderate to high back rest to improve venous return to the heart. In lowering BP, Nonvasodilating IV meds such as Nicardipine, Labetalol and Esmolol should be used instead of Hydralazine. The correct answer is: Initiate osmotic agents as soon as possible

Answer 3

The correct answer is: 2

Answer 4

An aneurysm of the posterior communicating artery will compress the third cranial nerve due to its proximity to the latter. This would result to an ipsilateral third cranial nerve is palsy, and present with pupillary dilation, and loss of ipsilateral (but retained contralateral) light reflex. Focal pain above or behind the eye, may occur with an expanding aneurysm at the junction of the posterior communicating artery and the internal carotid artery. Aneurysms of the Anterior circulation (ACA or Acomm) would present with leg weakness. Aneurysms involving the posterior inferior cerebellar artery or anterior inferior cerebellar artery often present with occipital and posterior cervical pain. MCA aneurysms may present with pain in or behind the eye and in the low temple but this would not present with third nerve palsies. The correct answer is: Posterior Communicating Artery

Answer 5

The correct answer is: 3

Answer 6

HSV encephalitis should be considered when clinical features suggest involvement of the inferomedial frontotemporal lobes. This includes olfactory and gustatory hallucinations, anosmia, bizaare behavior or memory changes. The correct answer is: HSV encephalitis

Answer 7

Progressive multifocal leukoencephalopathy is characterized by multiple areas of demyelination of varying sizes but sparing the optic nerves and spinal cord. This is due to crystalline arrays of JCV virus particles in oligodendrocytes. Patients often present with visual deficits typically a homonymous hemianopsia (45%), mental impairment (38%), weakness and ataxia. HIV encephalitis on the other hand present with waxing and waning episodes of psychomotor retardation and decreased concentration. Patients with CSF lymphoma would present focal symptoms depending on the site of the lesion, as opposed to multifocal symptoms seen in PML. Although autoimmune encephalitis would also present with behavioral changes, it is usually seen in patients with ovarian tumors, and not with HIV infection. The correct answer is: Progressive multifocal leukoencephalopathy

Answer 8

The patient initially presented with community acquired pneumonia which is the most important risk factor in developing pneumococcal meningitis. The organisms most often responsible for community-acquired bacterial meningitis are Streptococcus pneumoniae (~50%), Neisseria meningitidis (~25%), group B streptococci (~15%), and Listeria monocytogenes (~10%). Haemophilus influenzae type b accounts for <10% of cases of bacterial meningitis in most series. There are a number of predisposing conditions that Additional risk factors include coexisting acute or chronic pneumococcal sinusitis or otitis media, alcoholism, diabetes, splenectomy, hypogammaglobulinemia, complement deficiency, and head trauma with basilar skull fracture and CSF rhinorrhea The correct answer is: Streptococcus pnuemoniae

Answer 9

The combination of unrelenting headache, stiff neck, fatigue, night sweats, and fever with a CSF lymphocytic pleocytosis and a mildly decreased glucose concentration is highly suspicious for tuberculous meningitis. Signs and symptoms of viral and bacterial meningitis commonly develop within a few days to a week (acute presentation). The CSF in viral meningitis would have normal glucose. The CSF in bacterial meningitis would show neutrophilic pleocytosis. Aseptic meningitis would have unremarkable CSF findings The correct answer is: TB meningitis

Answer 10

The correct answer is: Cryptococcus neoformans

Answer 11

This is a typical case of TB meningitis, with a subacute onset of symptoms and sudden focal deficit or stroke due to arteritis. The focal deficits due to empyema, brain abscesses and metastasis usually present gradually. The correct answer is: Arteritis

Answer 12

Lower extremity weakness with headache and decreased sensorium are signs most compatible with increased intracranial pressure. In fungal meningitis, the most common complication is also hydrocephalus. Patients who develop hydrocephalus should receive a CSF diversion device. A ventriculostomy can be used until CSF fungal cultures are sterile, at which time the ventriculostomy is replaced by a ventriculoperitoneal shunt. Arteritis will present with focal neurologic deficits, while spinal meningitis will present with multiple radiculopathies. Status epilepticus would present with seizures The correct answer is: Hydrocephalus

Answer 13

The correct answer is: Migraine with typical aura

Answer 14

The patient’s premonitory symptom of tunneling of vision, gradual transition to unconsciousness and tonic movements lasting 10 seconds are features seen in syncope. Seizures usually present with immediate loss of consciousness lasting minutes, with tonic / clonic moevements lasting 30-60 seconds. Disorientation in seizures would last many minutes to hours while in syncope, it would last for less than 5 minutes. Patients with pseudoseizures present with side-to- side turning of the head, asymmetric and large-amplitude shaking movements of the limbs, twitching of all four extremities without loss of consciousness, and pelvic thrusting. In transient ischemic attack, there is usually a focal weakness that resolves in 1 hour with no evidence of infarction in imaging. The correct answer is: Syncope

Answer 15

Atonic seizures are characterized by sudden loss of postural muscle tone lasting 1–2s. The EEG shows brief, generalized spike-and-wave discharges followed immediately by diffuse slow waves that correlate with the loss of muscle tone. Focal seizures frequently begin with an aura, as opposed to the absence of aura in absence seizure. In focal seizures, the patient is typically confused following the seizure, and the transition to full recovery of consciousness may range from seconds up to an hour. In absence seizure, there is no post ictal confusion and the patient goes back to her previous activities as if nothing happened. The EEG in absence in typical absence seizure shows 3 Hz spike and slow discharges. Myoclonic seizures present with sudden and brief muscle contraction that may involve one part of the body or the entire body. The EEG shows bilaterally synchronous spike-and-slow-wave discharges immediately prior to the movement and muscle artifact associated with the myoclonus. The correct answer is: Typical absence seizures

Answer 16

in elderly nonhypertensive patients, cerebral amyloid angiopathy should be considered, especially those with lobar hemorrhages and dementia. Hypertensive hemorrhages usually result from spontaneous rupture of DEEP PENETRATING arteries in the brain. This is because small sized arteries in the basal ganglia are most prone to hypertension induced vascular injury. Most intracerebral hemorrhages would have significant hematoma expansion within 24 hours of stroke onset; this is as opposed to large infarcts who would develop significant edema at Day 3-5 from the onset of stroke. The correct answer is: In elderly nonhypertensive patients, cerebral amyloid angiopathy should be considered

Answer 17

The gray matter is composed predominantly of neuronal cell bodies. Hence disorders in the grey matter would often present with seizures, early cognitive decline and movement disorders. On the other hand, the white matter is composed of axons, their myelin and glial cells which transmit signals to the other cells in the central nervous system. In white matter disorders, these signals are interrupted hence long track signs involving motor, sensory and cerebellar pathways are seen in these patients. The correct answer is: Long tract signs

Answer 18

The definitive management to prevent rerupture of aneurysm is through “clipping” by a neurosurgeon or “coiled” by an endovascular surgeon. These patients should be referred immediately since early aneurysm repair prevents rerupture and allows the safe application of techniques to improve blood flow in the brain. Treatment with the calcium channel antagonist nimodipine (60 mg or 2 tabs of 30mg q4) improves outcome, perhaps by preventing ischemic injury rather than reducing the risk of vasospasm. Glucocorticoids may help reduce the head and neck ache caused by the irritative effect of the subarachnoid blood. However, there is no good evidence that they reduce cerebral edema, are neuroprotective, or reduce vascular injury, and their routine use therefore is not recommended. Free-water restriction is contraindicated in patients with SAH at risk for DCI because hypovolemia and hypotension may occur and precipitate cerebral ischemia. The correct answer is: Immediate referral to a neurosurgeon or endovascular surgeon is recommended for all patients

Answer 19

Aggressive lowering of SBP to 140–180 mmHg acutely is usually considered in hypertensive ICH but less aggressive measures should be used in hypertensive encephalopathy and reversible posterior leukoencephalopathy. This is because stroke can occur if blood pressure is lowered too rapidly. MRI brain imaging shows a pattern of typically posterior (occipital > frontal) brain edema that is reversible The hypertension may be essential or due to chronic renal disease, acute glomerulonephritis, acute toxemia of pregnancy, pheochromocytoma, or other causes. In most cases, ICP and CSF protein levels are elevated. The correct answer is: The hypertension may be caused by acute toxemia of pregnancy

Answer 20

Platelet transfusions should only be given in patients on antiplatelets if these patients present with thrombytopenia. In a recent trial, for ICH patients on antiplatelets but without thrombocytopenia, platelet transfusion suggested no benefit and was noted to have possible harm . Administration of two doses of Idarizucimab reverses the anticoagulation effect of dabigatran quickly. A phase 3 trial of treatment with recombinant factor VIIa reduced hematoma expansion in ICH patients. However, clinical outcomes were not improved, so use of this drug is not recommended. When ICH is associated with thrombocytopenia (platelet count <50,000/μL), transfusion of fresh platelets is indicated The correct answer is: Thrombocytopenia should be corrected with platelet transfusion

Answer 21

For cerebellar hemorrhages, a neurosurgeon should be consulted immediately to assist with the evaluation; most cerebellar hematomas >3 cm in diameter will require surgical evacuation. If the patient is alert without focal brainstem signs and if the hematoma is <1 cm in diameter, surgical removal is usually unnecessary. Patients with hematomas between 1 and 3 cm require careful observation for signs of impaired consciousness, progressive hydrocephalus, and precipitous respiratory failure. Hydrocephalus due to cerebellar hematoma requires surgical evacuation and should not be treated solely with ventricular drainage. The correct answer is: Immediate referral to a neurosurgeon should be done to assist with patient evaluation

Answer 22

Pinpoint pupils are seen in patients with pontine hemorrhage. Aphasia, often with preserved verbal repetition, may occur after hemorrhage into the dominant thalamus. A homonymous visual field defect may also be seen in thalamic bleed. An ipsilateral Horner’s syndrome and retraction nystagmus may also be seen in these patients. The correct answer is: Aphasia with preserved verbal repetition.

Answer 23

The correct answer is: CSF HSV PCR may be negative in the 1st 3 days of symptoms of HSV encephalitis

Answer 24

In the treatment of HSV encephalitis, IV Acyclovir is given at 10mg/kg q8 for 21 days in adults. Neonates are given 20mg/kg IV Acvclovir q8. Oral Valacyclovir has not been evaluated as a supplemental therapy after IV acyclovir is given in patients with HSV encephalitis. IV acyclovir should be diluted at a concentration <7mg/mL prior to infusion and slowly infused over 1 hour to prevent renal dysfunction. Because of the high frequency of seizures in severe cases of encephalitis, seizure prophylaxis should be considered in severe cases of encephalitis. The correct answer is: Seizure prophylaxis should be considered in severe cases of encephalitis

Answer 25

The quadrivalent (serogroups A, C, W-135 and Y) meningococcal glycoconjugate vaccine is routinely given to 11-16 year old children. However, since the vaccine does not contain the serogroup B, which is responsible to 1/3 of meningococcal disease, vaccination with the serogroup B meningococcal (Men B) vaccine may be done for young adults age 16-23. There was no recommendation for the vaccine for immunocompromised individuals and adults 65 years old and above. The correct answer is: Vaccination with the serogroup B meningococcal (Men B) vaccine for young adults age 16-23

Answer 26

Airborne bacteria cannot directly access the CSF. They initially colonize the nasopharynx and has to become bloodborne in order for the them to reach the the intraventricular choroid plexus and access the CSF. The CSF has small amounts of immunoglobulin and complement proteins making them more susceptible to bacterial invasion. Phagocytosis of bacteria is impaired by the fluid nature of CSF, which is less conducive to phagocytosis than a solid tissue substrate like the brain parenchyma. The paucity of immunoglobulins and complement proteins, and not the fluid nature of CSF, prevent effective opsonization of bacteria. The correct answer is: The CSF has small amounts of immunoglobulin and complement proteins.

Answer 27

Many of the neurologic manifestations and complications of bacterial meningitis result from the immune response to the invading pathogen rather than from direct bacteria-induced tissue injury. As a result, neurologic injury can progress even after the CSF has been sterilized by antibiotic therapy. During the very early stages of meningitis, there is an increase in cerebral blood flow. Narrowing of the large arteries at the base of the brain due to encroachment by the purulent exudate in the SAS and infiltration of the arterial wall by inflammatory cells with intimal thickening (vasculitis) also occur and may result in ischemia and infarction, obstruction of branches of the middle cerebral artery by thrombosis, thrombosis of the major cerebral venous sinuses, and thrombophlebitis of the cerebral cortical veins. The correct answer is: Infiltration of the arteries by inflammatory cells may result in ischemia and infarction.

Answer 28

When bacterial meningitis is suspected, blood cultures should be immediately obtained and empirical antimicrobial and adjunctive dexamethasone therapy initiated without delay. In an immunocompetent patient with no known history of recent head trauma, a normal level of consciousness, and no evidence of papilledema or focal neurologic deficits, it is considered safe to perform LP without prior neuroimaging studies. Blood cultures should be obtained before empirical antibiotic therapy is initiated. The correct answer is: Empiric antibiotic therapy should be started without delay

Answer 29

Uncomplicated meningococcal meningitis should be treated with IV antibiotic therapy for 1 week. Pneumococcal meningitis should be treated with IV antibiotics for 2 weeks. While meningitis due to L. monocytogenes and gram negative bacilli such as P. aeruginosa should be treated with IV antibiotics for 3 weeks. The correct answer is: Streptococcal meningitis

Answer 30

Empirical therapy of tuberculous meningitis is often initiated on the basis of a high index of suspicion without adequate laboratory support. Initial therapy is a combination of isoniazid (300 mg/d), rifampin (10 mg/kg per day), pyrazinamide (30 mg/kg per day in divided doses), ethambutol (15–25 mg/kg per day in divided doses). The correct answer is: Isoniazid (300mg/day), Rifampicin (10mg/kg/day),) , Pyrazinamide (30mg/kg/day), Ethambutol (15-25mg/kg/day)

Answer 31

Dexamethasone therapy is recommended for HIV-negative patients with tuberculous meningitis. The dose is 12–16 mg/d for 3 weeks, and then tapered over 3 weeks. The correct answer is: After initial high dose Dexamethasone, it should be tapered over 3 weeks

Answer 32

The correct answer is: Urinary incontinence : hydrocephalus

Answer 33

CSF is produced by the choroid plexus and absorbed by the arachnoid villi. In basal meningitis, inflammatory deposits in the brainstem result to multiple cranial nerve palsies, not hydrocephalus. Stimulation of the nociceptive fibers in the meninges (not in the brain parenchyma) result to headache. Raised intracranial pressure may present with palsy of the sixth cranial nerve. Obstruction of CSF pathways at the foramina or arachnoid villi may produce hydrocephalus and signs and symptoms of raised intracranial pressure (ICP), including head- ache, vomiting, apathy or drowsiness, gait instability, papilledema, visual loss, impaired upgaze, or palsy of the sixth cranial nerve. The correct answer is: Raised intracranial pressure may present with palsy of the sixth cranial nerve.

Answer 34

In general, the risk of death from bacterial meningitis increases with (1) decreased level of consciousness on admission, (2) onset of seizures within 24 h of admission, (3) signs of increased ICP, (4) young age (infancy) and age >50, (5) the presence of comorbid conditions including shock and/or the need for mechanical ventilation, and (6) delay in the initiation of treatment. Decreased CSF glucose concentration (<2.2 mmol/L [<40 mg/dL]) and markedly increased CSF protein concentration (>3 g/L [> 300 mg/dL]) have been predictive of increased mortality. The correct answer is: Age >50

Answer 35

The correct answer is: Cell activation in the trigeminal nucleus results in the release of vasoactive neuropeptides, particularly calcitonin gene–related peptide (CGRP).

Answer 36

The sensory sensitivity that is characteristic of migraine is probably due to dysfunction of monoaminergic sensory control systems located in the brainstem and hypothalamus , not the parietal cortex. Dilation, not constriction, from the meningeal vessels initiates the trigeminovascular input, which passes through the trigeminal ganglion and synapses on second-order neurons in the trigeminocervical complex (TCC). Activation of cells in the trigeminal nucleus results in the release of vasoactive neuropeptides, particularly calcitonin gene–related peptide (CGRP), at vascular terminals of the trigeminal nerve and within the trigeminal nucleus. Neurons in the TCC project in the quintothalamic tract (not the spinothalamic tract) and, after decussating in the brainstem, synapse on neurons in the thalamus (contralateral to TCC due to the decussation). The correct answer is: Triptans are generally effective in migraine with aura, especially when given before the aura is completed.

Answer 37

The correct answer is: Midazolam 0.2mg/kg IV

Answer 38

The ingestion of domoic acid (not penicillin) which is an analogue of glutamate (the principal excitatory neurotransmitter in the brain), causes profound seizures via direct activation of excitatory amino acid receptors throughout the CNS. Penicillin (not domoic acid) which can lower the seizure threshold in humans and is a potent convulsant in experimental models, reduces inhibition by antagonizing the effects of GABA at its receptor. The basic mechanisms of other precipitating factors of seizures, such as sleep deprivation, fever, alcohol withdrawal, hypoxia, and infection, are not as well understood but presumably involve analogous perturbations in neuronal excitability. Similarly, the endogenous factors that determine an individual’s seizure threshold may relate to these properties as well. In absence (not in focal seizures), oscillatory behavior involves an interaction between GABAB receptors, T-type Ca2+ channels, and K+ channels located within the thalamus (not the cortex). The correct answer is: Fever, alcohol withdrawal, hypoxia, and infection cause seizure due to analogous perturbations in neuronal excitability.

Answer 39

The correct answer is: Flunarizine: drowsiness

Answer 40

Intracerebral hemorrhages (ICH) due to hypertension are commonly located in the subcortical region due to the spontaneous rupture of small penetrating arteries deep in the brain, such as the putamen (part of the basal ganglia) and the thalamus. ICH due to metastatic brain tumors, cerebral amyloid angiopathy and capillary telangiectasia are seen in the cortical areas of the brain. The correct answer is: Uncontrolled hypertension

Answer 41

The correct answer is: Putamen

Answer 42

The characteristic CSF findings in viral encephalitis are: normal glucose and mildly elevated protein concentration. A CSF pleocytosis (>5 cells/μL) occurs in >95% of immunocompetent patients with documented viral encephalitis. Only about 20% of patients with encephalitis will have a significant number of red blood cells (>500/μL) in the CSF in a nontraumatic tap. The pathologic correlate of this finding may be a hemorrhagic encephalitis of the type seen with HSV. The correct answer is: CSF pleocytosis

Answer 43

Cushing reflex (bradycardia, hypertension, and irregular respirations) is a sign raised ICP The correct answer is: Bradycardia, Hypertension and irregular respirations

Answer 44

The correct answer is: CSF/serum glucose <0.4

Answer 45

The correct answer is: Ceftriaxone 4g / day, q12h

Answer 46

The correct answer is: Piperacillin Tazobactam

Answer 47

The correct answer is: Nausea

Answer 48

The correct answer is: Phenytoin

Answer 49

Migraine must be differentiated from tension type headache, which is reported to be the most common primary headache disorder. Migraine is the second most common cause of headache, and the most common headache related cause of disability in the world. Cluster headaches and nummular headaches are less frequent compared to migraine and tension type headache. The correct answer is: Tension type headache

Answer 50

A course of glucocorticoids, given as prednisone 60–80 mg daily during the first 5 days and then tapered over the next 5 days, modestly shortens the recovery period and improves the functional outcome in Bell’s palsy. Although large and well-controlled randomized trials found no added benefit of the antiviral agents valacyclovir (1000 mg daily for 5–7 days) or acyclovir (400 mg five times daily for 10 days) compared to glucocorticoids alone, some earlier data suggested that combination therapy with prednisone plus valacyclovir might be marginally better than prednisone alone, especially in patients with severe clinical presentations The correct answer is: Prednisone 60 – 80 mg daily for the first 5 days

Answer 51

Causes of sudden-onset neuro symptoms that may mimic stroke: Seizure An adequate history from an observer that no convulsive activity occurred at the onset usually excludes seizure, although ongoing complex partial seizures without tonic-clonic activity can on occasion mimic stroke. Intracranial tumor Tumors may present with acute neurologic symptoms due to hemorrhage, seizure, or hydrocephalus. Migraine Surprisingly, migraine can mimic stroke, even in patients without a significant migraine history. When migraine develops without head pain (acephalgic migraine), the diagnosis can be especially difficult. Metabolic encephalopathy Can cause sudden symptoms due to unmasking of old neurologic abnormalities The correct answer is: Hepatic encephalopathy

Answer 52

Episodes of stroke symptoms that last only briefly; the standard definition of duration is <24 h, but most TIAs last <1 h If a relevant brain infarction is identified on brain imaging, the clinical entity is now classified as stroke regardless of the duration of symptoms. A normal brain imaging study following a TIA does not rule-out TIA; rather, the clinical syndrome is diagnostic. The causes of TIA are similar to the causes of ischemic stroke, but because TIAs may herald stroke, they are an important risk factor that should be considered separately and urgently. TIAs may arise from emboli to the brain or from in situ thrombosis of an intracranial vessel. With a TIA, the occluded blood vessel reopens and neurologic function is restored. The correct answer is: An infarction on brain imaging even after resolution of the signs and symptoms classify his condition as a stroke.

Answer 53

Complete MCA syndromes: most often due to an embolus occluding the stem of the artery Partial MCA syndroms: due to cortical collateral blood flow and differing arterial configurations or emboli that enter the proximal MCA without complete occlusion, occlude distal MCA branches, or fragment and move distally • Partial syndromes due to embolic occlusion of a single branch --> hand, or arm and hand, weakness alone (brachial syndrome) or facial weakness with nonfluent (Broca) aphasia, with or without arm weakness (frontal opercular syndrome). * Proximal superior division – supplies large portions of the frontal and parietal cortices --> combination of sensory disturbance, motor weakness, and nonfluent aphasia * Inferior division of the MCA - supplies posterior part (temporal cortex) of the dominant hemisphere --> fluent (Wernicke’s) aphasia without weakness * Jargon speech and an inability to comprehend written and spoken language are prominent features, often accompanied by a contralateral, homonymous superior quadrantanopia. * Inferior division of the MCA in the nondominant hemisphere --> hemineglect or spatial agnosia without weakness The correct answer is: Inferior division of the middle cerebral artery

Answer 54

The correct answer is: Oral contraceptives

Answer 55

* Once the diagnosis of stroke is made, a brain imaging study is necessary to determine if the cause of stroke is ischemia or hemorrhage. * Computed tomography (CT) imaging of the brain is the standard imaging modality to detect the presence or absence of intracranial hemorrhage. * Conventional x-ray cerebral angiography is the gold standard for identifying and quantifying atherosclerotic stenoses of the cerebral arteries and for identifying and characterizing other pathologies, including aneurysms, vasospasm, intraluminal thrombi, fibromuscular dysplasia, arteriovenous fistulae, vasculitis, and collateral channels of blood flow. The correct answer is: Computed tomography imaging

Answer 56

* Identification and control of modifiable risk factors, and especially hypertension, is still the best strategy to reduce the burden of stroke, and the total number of strokes could be reduced substantially by these means. * Platelet antiaggregation agents can prevent atherothrombotic events, including TIA and stroke, by inhibiting the formation of intraarterial platelet aggregates. * But long-term use of clopidogrel in combination with aspirin is NOT recommended for stroke prevention, based on the CAPRIE, MATCH, and CHARISMA trials. * The short-term combination of clopidogrel with aspirin may be effective in preventing second stroke, however. * Data do NOT support the use of long-term VKAs for preventing atherothrombotic stroke for either intracranial or extracranial cerebrovascular disease. * The Warfarin-Aspirin Recurrent Stroke Study (WARSS) found no benefit of warfarin sodium (INR 1.4–2.8) over aspirin, 325 mg, for secondary prevention of stroke but did find a slightly higher bleeding rate in the warfarin group; a European study confirmed this finding. * Surgical and endovascular procedures (such as balloon angioplasty for the latter) are for therapy, not prevention. The correct answer is: Identification and control of modifiable risk factors, and especially hypertension and diabetes

Answer 57

• Primary prevention is different from secondary, and general population excludes certain patients; for example, clopidogrel combined with aspirin was more effective than aspirin alone in preventing vascular events, principally stroke, but increased the risk of major bleeding, in patients with AF. • Aspirin acetylates platelet cyclooxygenase, which irreversibly inhibits the formation in platelets of thromboxane A2, a platelet aggregating and vasoconstricting prostaglandin. o This effect is permanent and lasts for the usual 8-day life of the platelet. o Higher doses of aspirin have not been proven to be more effective than lower doses. • Ticlopidine and clopidogrel block the adenosine diphosphate (ADP) receptor on platelets and thus prevent the cascade resulting in activation of the glycoprotein IIb/IIIa receptor that leads to fibrinogen binding to the platelet and consequent platelet aggregation. o Ticlopidine is more effective than aspirin; however, it has the disadvantage of causing diarrhea, skin rash, and, in rare instances, neutropenia and thrombotic thrombocytopenic purpura (TTP). o Clopidogrel rarely causes TTP but does not cause neutropenia. • Dipyridamole is an antiplatelet agent that inhibits the uptake of adenosine by a variety of cells, including those of the vascular endothelium. o The accumulated adenosine is an inhibitor of aggregation. The correct answer is: Statin drugs reduce the risk of stroke even in patients without elevated LDL or low HDL.

Answer 58

Complete syndrome of anterior choroidal artery occlusion consists of: - contralateral hemiplegia - hemianesthesia (hypesthesia) - homonymous hemianopia. However, because this territory is also supplied by penetrating vessels of the proximal MCA and the posterior communicating and posterior choroidal arteries, minimal deficits may occur, and patients frequently recover substantially. The correct answer is: Anterior choroidal artery

Answer 59

Unlike the myocardial vessels, artery-to-artery embolism, rather than local thrombosis, appears to be the dominant vascular mechanism causing large-vessel brain ischemia. The correct answer is: Local thrombus formation rather than artery-to-artery embolism appears to be the dominant vascular mechanism causing large-vessel brain ischemia.

Answer 60

Focal cerebral infarction occurs via two distinct pathways: 1. a necrotic pathway in which cellular cytoskeletal breakdown is rapid, due principally to energy failure of the cell 2. an apoptotic pathway in which cells become programmed to die Ischemia produces necrosis by starving neurons of glucose and oxygen, which in turn results in failure of mitochondria to produce ATP. Without ATP, membrane ion pumps stop functioning and neurons depolarize, allowing intracellular calcium to rise. Cellular depolarization also causes glutamate release from synaptic terminals; excess extracellular glutamate produces neurotoxicity by activating postsynaptic glutamate receptors that increase neuronal calcium influx. Free radicals are produced by degradation of membrane lipids and mitochondrial dysfunction. Free radicals cause catalytic destruction of membranes and likely damage other vital functions of cells. Lesser degrees of ischemia, as are seen within the ischemic penumbra, favor apoptotic cellular death causing cells to die days to weeks later. The correct answer is: Hyperglycemia worsens brain injury during ischemia.

Answer 61

* After the clinical diagnosis of stroke is made, an orderly process of evaluation and treatment should follow. * The first goal is to prevent or reverse brain injury. Attend to the patient’s airway, breathing, and circulation (ABCs), and treat hypoglycemia or hyperglycemia if identified by finger stick testing. * Perform an emergency non-contrast head CT scan to differentiate between ischemic stroke and hemorrhagic stroke; there are no reliable clinical findings that conclusively separate ischemia from hemorrhage, although a more depressed level of consciousness, higher initial blood pressure, or worsening of symptoms after onset favor hemorrhage, and a deficit that is maximal at onset, or remits, suggests ischemia. * Treatments designed to reverse or lessen the amount of tissue infarction and improve clinical outcome fall within six categories: (1) medical support, (2) IV thrombolysis, (3) endovascular revascularization, (4) antithrombotic treatment, (5) neuroprotection, and (6) stroke centers and rehabilitation. The correct answer is: Deficit that is maximal at onset, or remits

Answer 62

The correct answer is: Infuse through central line

Answer 63

Two clinical syndromes with occlusion of the posterior cerebral artery (PCA): (1) P1 syndrome: midbrain, subthalamic, and thalamic signs, which are due to disease of the proximal P1 segment of the PCA or its penetrating branches (thalamogeniculate, Percheron, and posterior choroidal arteries) (2) P2 syndrome: cortical temporal and occipital lobe signs, due to occlusion of the P2 segment distal to the junction of the PCA with the posterior communicating artery. P1 • Infarction usually occurs in the ipsilateral subthalamus, medial thalamus and in the ipsilateral cerebral peduncle and midbrain à third nerve palsy with CL ataxia (Claude’s syndrome) or with contralateral hemiplegia (Weber’s syndrome) • Occlusion of the penetrating branches of thalamic and thalamogeniculate arteries produces less extensive lacunar syndromes à thalamic Déjérine-Roussy syndrome: CL hemisensory loss followed later by an agonizing, searing, or burning pain in the affected area P2 * Occlusion of the distal PCA causes infarction of the medial temporal and occipital lobes à CL homonymous hemianopia without macula sparing * Bilateral infarction in the distal PCAs à cortical blindness (blindness with preserved pupillary light reaction), patient is often unaware of the blindness or may even deny it (Anton’s syndrome) * Infarctions secondary to low flow in the “watershed” between the distal PCA and MCA territories --> bilateral visual association area lesions --> Balint’s syndrome, a disorder of the orderly visual scanning of the environment o Persistence of a visual image for several minutes despite gazing at another scene (palinopsia) or an inability to synthesize the whole of an image (asimultanagnosia) The correct answer is: Cortical blindness but patient may deny it (Anton’s syndrome)

Answer 64

The correct answer is: Pentobarbital

Answer 65

Issues relating to Women with Epilepsy • Most women with epilepsy who become pregnant will have an uncomplicated gestation and deliver a normal baby. However, epilepsy poses some important risks to a pregnancy. * Seizure frequency during pregnancy: unchanged in ~50% of women, increase in ~30%, and decrease in ~20% * Enzyme-inducing drugs such as phenytoin cause a transient and reversible deficiency of vitamin K–dependent clotting factors in ~50% of newborn infants. Although neonatal hemorrhage is uncommon, the mother should be treated with oral vitamin K (20 mg/d, phylloquinone) in the last 2 weeks of pregnancy, and the infant should receive intramuscular vitamin K (1 mg) at birth. The correct answer is: She will most likely have a complicated gestation and deliver a baby with at least mild physical or developmental defects.

Answer 66

Coma and seizures are common accompaniments of large shifts in sodium and water balance in the brain. Sodium levels <125 mmol/L induce confusion, and levels <119 mmol/L are typically associated with coma and convulsions, especially when these levels are achieved quickly. The correct answer is: 115-119 mmol/L

Answer 67

Unlike hypoxia-ischemia, which causes neuronal destruction, most metabolic disorders such as hypoglycemia, hyponatremia, hyperosmolarity, hypercapnia, hypercalcemia, and hepatic and renal failure cause only minor neuropathologic changes. The correct answer is: Hypoxia-ischemia

Answer 68

Patient should first be observed without intervention by the examiner. Tossing about in the bed, reaching up toward the face, crossing legs, yawning, swallowing, coughing, or moaning reflect a drowsy state that is close to normal awakeness. Lack of restless movements on one side or an outturned leg suggests hemiplegia. Subtle, intermittent twitching movements of a foot, finger, or facial muscle may be the only sign of seizures. Multifocal myoclonus almost always indicates a metabolic disorder, particularly uremia, anoxia, drug intoxication, or rarely a prion disease. In a drowsy and confused patient, bilateral asterixis is a sign of metabolic encephalopathy or drug intoxication. Asterixis is tested by extending the arms, dorsiflexing the wrists, and spreading the fingers to observe for the “flap” at the wrist. The flap is due to irregular myoclonic lapses of posture caused by involuntary 50-200-ms silent periods appearing in tonically active muscles. The correct answer is: Metabolic encephalopathy

Answer 69

Oculocephalic reflexes should never be elicited in patients with possible head or neck trauma, as vigorous head movements can precipitate or worsen a spinal cord injury The correct answer is: Oculocephalic reflexes

Answer 70

The correct answer is: If a patient had a seizure and a brain infection is possible

Answer 71

The most common causes of GCSE are anticonvulsant withdrawal or noncompliance, metabolic disturbances, drug toxicity, CNS infection, CNS tumors, refractory epilepsy, and head trauma. Sleep deprivation can be a precipitant though, including psychological or physical stress and hormonal changes as well. (P 3054) The correct answer is: Lack of sleep

Answer 72

The correct answer is: Cerebrovascular disease

Answer 73

All patients who have a possible seizure disorder should be evaluated with an EEG as soon as possible. The absence of electrographic seizure activity does not exclude a seizure disorder, however, because focal seizures may originate from a region of the cortex that cannot be detected by standard scalp electrodes. Presently, genetic testing is being done mainly in infants and children with epilepsy syndromes thought to have a genetic cause. However, genetic testing should also be considered in older patients with a history suggesting an undiagnosed genetic epilepsy syndrome that began early in life. The correct answer is: In many cases the diagnosis of a seizure is based solely on clinical grounds.

Answer 74

Catatonia is hypomobile and mute syndrome that occurs usually as part of a major psychosis, typically schizophrenia or major depression. Patients with make few voluntary or responsive movements, although they blink, swallow, and may not appear distressed. There are nonetheless signs that the patient is responsive. Akinetic mutism refers to a partially or fully awake state in which the patient is able to form impressions and think, as demonstrated by later recounting of events, but remains virtually immobile and mute. The condition results from damage in the regions of the medial thalamic nuclei or the frontal lobes (particularly lesions situated deeply or on the orbitofrontal surfaces) or from extreme hydrocephalus. In a small proportion of patients in the vegetative state from posttraumatic cases, meaningful cerebral activation in response to verbal and other stimuli have been demonstrated by functional MRI. The locked-in state describes an important type of pseudocoma in which an awake patient has no means of producing speech or volitional limb movement but retains voluntary vertical eye movements and lid elevation, thus allowing the patient to signal with a clear mind. The pupils are normally reactive. The correct answer is: Stuporous patients can be transiently awakened by vigorous stimuli and avoid or withdraw from uncomfortable or aggravating stimuli.

Answer 75

Oxygen consumption is 3.5 mL per 100 g/min, and glucose utilization is 5 mg per 100 g/min. Brain stores of glucose are able to provide energy for ~2 min after blood flow is interrupted, and oxygen stores last 8–10 s after the cessation of blood flow. The correct answer is: ~120 seconds

Answer 76

Pupillary reactions are examined with a bright, diffuse light. Reactive and round pupils of midsize (2.5–5 mm) essentially exclude upper midbrain damage, either primary or secondary to compression. A response to light may be difficult to appreciate in pupils <2 mm in diameter, and bright room lighting mutes pupillary reactivity. One enlarged and poorly reactive pupil (>6 mm) signifies compression or stretching of the third nerve from the effects of a cerebral mass above. Enlargement of the pupil contralateral to a hemispheral mass may occur but is infrequent. An oval and slightly eccentric pupil is a transitional sign that accompanies early midbrain–third nerve compression. The most extreme pupillary sign, bilaterally dilated and unreactive pupils, indicates severe midbrain damage, usually from compression by a supratentorial mass. Ingestion of drugs with anticholinergic activity, the use of mydriatic eye drops, nebulizer treatments, and direct ocular trauma are among the causes of misleading pupillary enlargement The correct answer is: Cholinergic drugs

Answer 77

The eyes look toward a hemispheral lesion and away from a brainstem lesion. Seizures involving the frontal lobe drive the eyes to the opposite side, simulating a pontine destructive lesion. The eyes may occasionally turn paradoxically away from the side of a deep hemispheral lesion (“wrong-way eyes”) The correct answer is: Toward

Answer 78

Shallow, slow, but regular breathing suggests metabolic or drug depression. Cheyne-Stokes respiration in its typical cyclic form, ending with a brief apneic period, signifies bihemispheral damage or metabolic suppression and commonly accompanies light coma. Rapid, deep (Kussmaul) breathing usually implies metabolic acidosis but may also occur with pontomesencephalic lesions. Agonal gasps are the result of lower brainstem (medullary) damage and are recognized as the terminal respiratory pattern of severe brain damage. The correct answer is: Cheyne-Stokes respiration

Answer 79

Two essential elements of Brain Death, after assuring that no confounding factors (e.g., hypothermia, drug intoxication) are present: 1. Widespread cortical destruction that is reflected by deep coma and unresponsive- ness to all forms of stimulation; 2. Global brainstem damage demonstrated by absent pupillary light reaction, absent corneal reflexes, loss of oculovestibular reflexes, and destruction of the medulla, manifested by complete and irreversible apnea. Diabetes insipidus is usually present, but may only develop hours or days after the other clinical signs of brain death appear. The pupils are usually midsized but may be enlarged. Loss of deep tendon reflexes is NOT required because the spinal cord remains functional. Occasionally other reflexes that originate from the spine may be present and should not preclude a diagnosis of brain death. The correct answer is: Loss of deep tendon reflexes

Answer 80

The immediate goal in a comatose patient is prevention of further nervous system damage. Hypotension, hypoglycemia, hypercalcemia, hypoxia, hypercapnia, and hyperthermia should be corrected rapidly. An oropharyngeal airway is adequate to keep the pharynx open in a drowsy patient who is breathing normally. Tracheal intubation is indicated if there is apnea, upper airway obstruction, hypoventilation, or emesis, or if the patient is at risk for aspiration. Mechanical ventilation is required if there is hypoventilation or a need to induce hypocapnia in order to lower ICP. IV access is established. In cases of suspected ischemic stroke including basilar thrombosis with brainstem ischemia, IV tissue plasminogen activator or mechanical embolectomy is often used after cerebral hemorrhage has been excluded and when the patient presents within established time windows for these interventions. The correct answer is: Hypotension should be corrected slowly to avoid reperfusion injury.

Answer 81

In the ICU setting, several metabolic causes of an altered level of consciousness predominate. • Hypercarbic encephalopathy can present with headache, confusion, stupor, or coma. * Hypoventilation syndrome occurs most frequently in patients with a history of chronic CO2 retention who are receiving oxygen therapy for emphysema or chronic pulmonary disease. The elevated Paco2 leading to CO2 narcosis may have a direct anesthetic effect, and cerebral vasodilation from increased Paco2 can lead to increased ICP. * Hepatic encephalopathy is suggested by asterixis and can occur in chronic liver failure or acute fulminant hepatic failure. * Both hyperglycemia and hypoglycemia can cause encephalopathy, as can hypernatremia and hyponatremia. * Confusion, impairment of eye movements, and gait ataxia are the hall- marks of acute Wernicke’s disease. – thiamine deficiency due to alcohol • Wernicke’s Triad o Characteristic clinical triad: ophthalmoplegia, ataxia, and global confusion. o However, only one-third of patients with acute Wernicke’s disease present with the classic clinical triad. o Most patients are profoundly disoriented, indifferent, and inattentive, although rarely they have an agitated delirium related to ethanol withdrawal. The correct answer is: Delirium

Answer 82

Focal Seizures with Intact Awareness • Can have motor manifestations (such as tonic, clonic, or myoclonic movements) or nonmotor manifestations (such as sensory, autonomic, or emotional symptoms) without impairment of awareness • Three additional features of focal motor seizures: o Jacksonian march: Abnormal motor movements may begin in a very restricted region such as the fingers and gradually progress (over seconds to minutes) to include a larger portion of the extremity o Todd’s paralysis: localized paresis for minutes to many hours in the involved region following the seizure o Epilepsia partialis continua seizure may continue for hours or days; often refractory to medical therapy Focal Seizures with Impaired Awareness • Focal seizures may also be accompanied by a transient impairment of the patient’s ability to maintain normal contact with the environment. * The patient is unable to respond appropriately to visual or verbal commands during the seizure and has impaired recollection or awareness of the ictal phase. * Impaired awareness is usually accompanied by automatisms Generalized onset seizure • Typical Absence Seizures * Atypical Absence Seizures * Generalized, Tonic-Clonic Seizures * Atonic Seizures * Myoclonic Seizures • Epileptic Spasms The correct answer is: Simple focal seizures

Answer 83

Focal seizures can spread to involve both cerebral hemispheres and produce a generalized seizure, usually of the tonic-clonic variety. This evolution is observed frequently following focal seizures arising from a region in the frontal lobe, but may also be associated with focal seizures occurring elsewhere in the brain. A focal seizure that evolves into a generalized seizure is often difficult to distinguish from a primary generalized onset tonic-clonic seizure, because bystanders tend to emphasize the more dramatic, generalized convulsive phase of the seizure and overlook the more subtle, focal symptoms present at onset. In some cases, the focal onset of the seizure becomes apparent only when a careful history identifies a preceding aura. Often, however, the focal onset is not clinically evident and may be established only through careful EEG analysis. The correct answer is: Frontal lobe

Answer 84

Autosomal dominant partial epilepsy with auditory features (ADPEAF) • Idiopathic lateral temporal lobe epilepsy with auditory symptoms or aphasia as a major focal seizure manifestation; age of onset usually between 10 and 25 years Juvenile myoclonic epilepsy is a generalized seizure disorder of unknown cause that appears in early adolescence and is usually characterized by bilateral myoclonic jerks that may be single or repetitive. • Myoclonic seizures most frequent in the morning after awakening and can be provoked by sleep deprivation. • Consciousness is preserved unless the myoclonus is especially severe. • Many patients also experience GTC seizures, and up to one-third have absence seizures. • Although complete remission is relatively uncommon, the seizures usually respond well to appropriate anticonvulsant medication. • There is often a family history of epilepsy, and genetic linkage studies suggest a polygenic cause. Lennox-Gastaut syndrome occurs in children Triad of 1. multiple seizure types (usually including GTC, atonic, and atypical absence seizures) 2. EEG showing slow (<3 Hz) spike-and-wave discharges and a variety of other abnormalities 3. impaired cognitive function in most but not all cases. The correct answer is: Mesial temporal lobe epilepsy (MTLE)

Answer 85

Cerebral blood flow: • ~75 mL per 100 g/min in gray matter * ~30 mL per 100 g/min in white matter * Mean ~55 mL per 100 g/min The correct answer is: 75 mL per 100 g/min

Answer 86

43 mmol/L (0.2 g/dL) in nonhabituated patients generally causes impaired mental activity >65 mmol/L (0.3 g/dL) is associated with stupor The development of tolerance may allow some chronic alcoholics to remain awake at levels >87 mmol/L (0.4 g/dL). The correct answer is: 43

Answer 87

Peripheral nerves are composed of sensory, motor, and autonomic elements. Diseases can affect the cell body of a neuron or its peripheral processes, namely the axons or the encasing myelin sheaths. Most peripheral nerves are mixed and contain sensory and motor as well as autonomic fibers. Nerves can be subdivided into three major classes: large myelinated, small myelinated, and small unmyelinated. Motor axons are usually large myelinated fibers that conduct rapidly (~50 m/s). Sensory fibers may be any of the three types. Large-diameter sensory fibers conduct proprioception and vibratory sensation to the brain Smaller-diameter myelinated and unmyelinated fibers transmit pain and temperature sensation Autonomic nerves are also small in diameter. Peripheral neuropathies are further classified into those that primarily affect the cell body (e.g., neuronopathy or ganglionopathy), myelin (myelinopathy), and the axon (axonopathy). The correct answer is: Smaller diameter myelinated and unmyelinated fibers

Answer 88

Peripheral nerves are composed of sensory, motor, and autonomic elements. Diseases can affect the cell body of a neuron or its peripheral processes, namely the axons or the encasing myelin sheaths. Most peripheral nerves are mixed and contain sensory and motor as well as autonomic fibers. Nerves can be subdivided into three major classes: large myelinated, small myelinated, and small unmyelinated. Motor axons are usually large myelinated fibers that conduct rapidly (~50 m/s). Sensory fibers may be any of the three types. Large-diameter sensory fibers conduct proprioception and vibratory sensation to the brain Smaller-diameter myelinated and unmyelinated fibers transmit pain and temperature sensation Autonomic nerves are also small in diameter. Peripheral neuropathies are further classified into those that primarily affect the cell body (e.g., neuronopathy or ganglionopathy), myelin (myelinopathy), and the axon (axonopathy). Diabetic distal symmetric sensory and sensorimotor polyneuropathy (DSPN) - most common form of diabetic neuropathy; manifests as sensory loss beginning in the toes that gradually progresses over time up the legs and into the fingers and arm Autonomic neuropathy is typically seen in combination with DSPN - abnormal sweating, dysfunctional thermoregulation, dry eyes and mouth, pupillary abnormalities, cardiac arrhythmias, postural hypotension, GI abnormalities (e.g., gastroparesis, postprandial bloating, chronic diarrhea, or constipation), and genitourinary dysfunction Diabetic Radiculoplexus Neuropathy (Diabetic Amyotrophy or Bruns-Garland Syndrome) - presenting manifestation of DM in ~1/3 of patients; typically, patients present with severe pain in the low back, hip, and thigh in one leg; rarely, diabetic polyradiculoneuropathy begins in both legs at the same time Atrophy and weakness of proximal and distal muscles in the affected leg become apparent within a few days or weeks. The neuropathy is often accompanied or heralded by severe weight loss. Weakness usually progresses over several weeks or months, but can continue to progress for 18 months or more. Subsequently, there is slow recovery but many are left with residual weakness, sensory loss, and pain The correct answer is: Diabetic radiculoplexus neuropathy

Answer 89

Now the most common primary brain tumor, accounting for ~35% of the total. Incidence increases with age More common in women and in patients with neurofibromatosis type 2 (NF2); also occur more commonly in patients with a past history of cranial irradiation Arise from the dura mater; composed of neoplastic meningothelial (arachnoidal cap) cells. They are most commonly located over the cerebral convexities, especially adjacent to the sagittal sinus, but they can also occur in the skull base and along the dorsum of the spinal cord. Meningiomas are classified by the WHO into three histologic grades of increasing aggressiveness: grade I (benign), grade II (atypical), and grade III (malignant). Many are found incidentally following neuroimaging for unrelated reasons. Can present with headaches, seizures, or focal neurologic deficits Characteristic appearance on imaging: densely enhancing extra-axial tumor arising from the dura; typically with a dural tail, consisting of thickened, enhanced dura extending like a tail from the mass. The main differential diagnosis of meningioma is a dural metastasis. If the meningioma is small and asymptomatic, no intervention is necessary and the lesion can be observed with serial MRI studies. Larger, symptomatic lesions should be resected. If complete resection is achieved, the patient is cured. Incompletely resected tumors tend to recur, although the rate of recurrence can be very slow with grade I tumors. Tumors that cannot be resected, or can only be partially removed, may benefit from external-beam RT or stereotactic radiosurgery (SRS). These treatments may also be helpful in patients whose tumor has recurred after surgery. The correct answer is: No intervention is necessary; observed with serial MRI studies

Answer 90

The correct answer is: Vasculitis

Answer 91

``` Cranial magnetic resonance imaging (MRI) is the preferred diagnostic test for any patient suspected of having a brain tumor and should be performed with gadolinium contrast administration. Computed tomography (CT) scan should be reserved for those patients unable to undergo MRI. In general, MRI is more sensitive than CT for detection of lesions affecting the PNS and CNS, particularly those of the spinal cord, cranial nerves, and posterior fossa structures. Diffusion MR, a sequence sensitive to the microscopic motion of water, is the most sensitive technique for detecting acute ischemic stroke of the brain or spinal cord, and it is also useful in the detection and characterization of encephalitis, abscess, Creutzfeldt-Jacob disease, cerebral tumors and acute demyelinating lesions. CT, however, is acquired quickly, making it a pragmatic choice for patients with acute changes in mental status, suspected hemorrhage, and acute intracranial or spinal trauma. CT is also more sensitive than MRI for visualizing fine osseous detail and is indicated in the initial imaging evaluation of conductive hearing loss and lesions affecting the skull base and calvarium. MR may, however, add important diagnostic information regarding bone marrow infiltrative processes that are difficult to detect on CT. ``` The correct answer is: Brain tumors

Answer 92

Neuroimaging is the only test necessary to diagnose a brain tumor. Laboratory tests are rarely useful, although patients with metastatic disease may have elevation of a serum tumor marker (e.g., β human chorionic gonadotropin [β-hCG] from testicular cancer). Additional testing such as cerebral angiogram, electroenceph- alogram (EEG), or lumbar puncture is rarely indicated or helpful. The correct answer is: Neuroimaging is the only test necessary.

Answer 93

Definitive treatment is based on the specific tumor type and includes surgery, radiotherapy, and chemotherapy. Symptomatic treatments apply to brain tumors of any type. Most high-grade malignancies are accompanied by substantial surrounding edema, which contributes to neurologic disability and raised intracranial pressure. Glucocorticoids are highly effective at reducing perilesional edema and improving neurologic function, often within hours of administration. • Dexamethasone - glucocorticoid of choice because of its relatively low mineralocorticoid activity; initial doses are 8–16 mg/d. Patients with brain tumors who present with seizures require antiepileptic drug therapy. • Agents of choice are drugs that do not induce the hepatic microsomal enzyme system (levetiracetam, topiramate, lamotrigine, valproic acid, and lacosamide) There is no role for prophylactic antiepileptic drugs in patients who have not had a seizure. Venous thromboembolic disease occurs in 20–30% of patients with high-grade gliomas or brain metastases. Prophylactic anticoagulants should be used during hospitalization and in nonambulatory patients. Those who have had either a deep vein thrombosis or pulmonary embolus can receive therapeutic doses of anticoagulation safely and without increasing the risk for hemorrhage into the tumor. Inferior vena cava filters are reserved for patients with absolute contraindications to anticoagulation such as recent craniotomy. The correct answer is: Glucocorticoids are highly effective at reducing perilesional edema and improving neurologic function, often within hours of administration.

Answer 94

The most common causes of acute generalized weakness leading to admission to a medical intensive care unit (ICU) are GBS and myasthenia gravis. However, weakness developing in critically ill patients while in the ICU is usually caused by critical illness polyneuropathy (CIP) or critical illness myopathy (CIM) or, much less commonly, by prolonged neuromuscular blockade. Both CIM and CIP develop as a complication of sepsis and multiple organ failure and usually present as an inability to wean a patient from a ventilator. Muscle stretch reflexes are absent or reduced. Serum creatine kinase (CK) is usually normal; an elevated serum CK would point to CIM as opposed to CIP. NCS reveal absent or markedly reduced amplitudes of motor and sensory studies in CIP, whereas sensory studies are relatively preserved in CIM. Needle EMG usually reveals profuse positive sharp waves and fibrillation potentials, and it is not unusual in patients with severe weakness to be unable to recruit motor unit action potentials. The pathogenic basis of CIP is not known. Perhaps circulating toxins and metabolic abnormalities associated with sepsis and multiorgan failure impair axonal transport or mitochondrial function, leading to axonal degeneration. The correct answer is: Muscle stretch reflexes are present.

Answer 95

Gliomas are the most common type of malignant primary brain tumor and are derived, based on their presumed lineage, into astrocytomas and oligodendrogliomas. Astrocytomas (WHO grade I) are the most common tumor of childhood. They occur typically in the cerebellum but may also be found elsewhere in the neuraxis, including the optic nerves and brainstem. Primary central nervous system lymphoma (PCNSL) is a rare non-Hodgkin lymphoma accounting for <3% of primary brain tumors. Medulloblastomas are the most common malignant brain tumor of childhood, accounting for ~20% of all primary CNS tumors among children. The correct answer is: Glioma

Answer 96

Arise from hematogenous spread and frequently originate from a lung primary or are associated with pulmonary metastases. Most metastases develop at the gray matter–white matter junction in the watershed distribution of the brain where intravascular tumor cells lodge in terminal arterioles. The distribution of metastases in the brain approximates the proportion of blood flow such that ~85% of all metastases are supratentorial and 15% occur in the posterior fossa. The most common sources of brain metastases are lung and breast carcinomas; melanoma has the greatest propensity to metastasize to the brain, being found in 80% of patients at autopsy. Other tumor types such as ovarian and esophageal carcinoma rarely metastasize to the brain. Prostate and breast cancers also have a propensity to metastasize to the dura and can mimic meningioma. Leptomeningeal metastases are common from hematologic malignancies and also breast and lung cancers. Spinal cord compression primarily arises in patients with prostate and breast cancer, tumors with a strong propensity to metastasize to the axial skeleton. The correct answer is: Melanoma

Answer 97

Guillain-Barre Syndrome Acute, frequently severe, and fulminant polyradiculoneuropathy; autoimmune in nature Manifests as a rapidly evolving areflexic motor paralysis with or without sensory disturbance; usual pattern is an ascending paralysis that may be first noticed as rubbery legs. Weakness typically evolves over hours to a few days and is frequently accompanied by tingling dysesthesias in the extremities. The legs are usually more affected than the arms, and facial diparesis is present in 50% of affected individuals. The lower cranial nerves are also frequently involved, causing bulbar weakness with difficulty handling secretions and maintaining an airway; the diagnosis in these patients may initially be mistaken for brainstem ischemia. Pain in the neck shoulder, back, or diffusely over the spine is also common in the early `stages of GBS, occurring in ~50% of patients. Most patients require hospitalization, and in different series, up to 30% require ventilatory assistance at some time during the illness. The correct answer is: Fever and constitutional symptoms are often present at the onset.

Answer 98

Myasthenia Gravis Neuromuscular junction (NMJ) disorder characterized by weakness and fatigability of skeletal muscles Underlying defect is a decrease in the number of available acetylcholine receptors (AChRs) at NMJs due to an antibody-mediated autoimmune attack Diagnosis is suspected on the basis of weakness and fatigability in the typical distribution described above, without loss of reflexes or impairment of sensation or other neurologic function. The suspected diagnosis should always be confirmed definitively before treatment is undertaken; this is essential because (1) other treatable conditions may closely resemble MG and (2) the treatment of MG may involve surgery and the prolonged use of drugs with potentially adverse side effects. Myasthenia Gravis Diagnosis Ice-pack Test • If a patient has ptosis, application of a pack of ice over a ptotic eye often results in improvement if the ptosis is due to an NMJ defect. • Hypothesized to be d/t less depletion of quanta of AChR in the cold and reduced activity of AChE at the NMJ. Autoantibodies Associated with MG Anti-AChR antibodies are detectable in the serum of ~85% of all myasthenic patients but in only about 50% of patients with weakness confined to the ocular muscles Presence is virtually diagnostic of MG, but a negative test does not exclude the disease Measured level of anti-AChR antibody does not correspond well with the severity of MG in different patients. Antibodies to MuSK are present in ~40% of AChR antibody–negative patients with generalized MG. Electrodiagnostic Testing (repetitive nerve stimulation) Best to test weak muscles or proximal muscle groups. Rapid reduction of >10% in the amplitude of the evoked responses in MG Anti-AChE medication should be stopped 6–12 h before testing. Anticholinesterase Test Drugs that inhibit the enzyme AChE allow ACh to interact repeatedly with the limited number of AChRs in MG, producing improvement in muscle strength. Edrophonium - rapid onset (30 s) and short duration (~5 min) effect • Initial IV dose of 2 mg of edrophonium; if definite improvement occurs, the test is considered positive and is terminated. If there is no change, the patient is given an additional 8 mg IV. ``` • The dose is administered in two parts because some patients react to with side effects such as nausea, diarrhea, salivation, fasciculations, and rarely with severe symptoms of syncope or bradycardia. IV atropine (0.6 mg) should be ready if these symptoms become troublesome. The edrophonium test is now reserved for patients with clinical findings that are suggestive of MG but w/ negative antibody, Edx testing, or ice-pack test. ``` The correct answer is: The presence of anti-acetylcholine receptor antibodies is diagnostic but a negative test does not exclude the disease

Answer 99

The correct answer is: Gastrointestinal bleeding in the last 3 weeks

Answer 100

The correct answer is: There is no evidence for the use of vitamin K antagonists over aspirin for secondary prevention of non-cardiogenic stroke

Answer 101

The correct answer is: Putamen

Answer 102

The correct answer is: 3 cm

Answer 103

The correct answer is: Herpesvirus

Answer 104

The correct answer is: Ampicillin + ceftriaxone + vancomycin

Answer 105

The correct answer is: Load with midazolam/propofol and then start a drip

Answer 106

The correct answer is: Hypermagnesemia

Answer 107

The correct answer is: Sumatriptan

Answer 108

The correct answer is: Lung

Answer 109

The correct answer is: 10-15%

Answer 110

The correct answer is: 5, yes, admission is necessary

Answer 111

The correct answer is: Primary intraventricular hemorrhage is rare and should prompt investigation for an underlying vascular anomaly

Answer 112

The correct answer is: Arteriovenous malformations consist of a tangle of abnormal vessels across the cortical surface or deep within the brain substance

Answer 113

The correct answer is: Leukoaraiosis

Answer 114

The correct answer is: CSF/serum glucose ratio of <0.4

Answer 115

The correct answer is: Rifampin

Answer 116

The correct answer is: Continue acyclovir and repeat the lumbar puncture

Answer 117

The correct answer is: Normal CSF cell count within 12 months and decrease in VDRL titer by two dilutions or revert to nonreactive within 2 years of completion of therapy

Answer 118

The correct answer is: Human T-cell lymphotropic virus-1

Answer 119

The correct answer is: Mesial Temporal Lobe Epilepsy Syndrome

Answer 120

The correct answer is: Sumatriptan

Answer 121

The correct answer is: Skin biopsy

Answer 122

The correct answer is: A course of five plasma exchanges over a 10-day period

NEUROLOGY Flashcards

(146 cards)