Section 7

Question 1

A 52-year-old retired golfer presents to the emergency department with severe abdominal pain. He states that the pain started a few days ago and was initially a dull backache. However, the pain has become unbearable. He describes the pain as a shooting pain that radiates from the back to the umbilicus, passing around the right side of the abdomen. He has otherwise been well and has no significant past medical history. His examination reveals a soft abdomen with audible bowel sounds. A sensory examination reveals reduced sensation in the right T10 dermatome. Which of the following additional signs is consistent with the underlying diagnosis?

Answer 1

1. Right iliac fossa pain of flexion and internal rotation of the right thigh
   2. Upward umbilical movement on abdominal wall contraction
2. Weakness of hip flexion
3. Pelvis tilt to left while standing on his right leg

• This patient has presented with radicular pain in the right T10 dermatome. The patient’s examination reveals reduced sensation of ipsilateral T 10 dermatome indicating the presence of spinal nerve compression. His golfing history and reduced sensation in the ipsilateral dermatome are consistent with T10 radiculopathy, possibly due to thoracic vertebral disc herniation.
• The compression of the spinal nerve will lead to paralysis of the muscle innervated by the involver nerve. Paralysis of abdominal muscle will lead to abnormal movement of the umbilicus on the contraction of the abdominal wall.
• This sign is also known as the Beevor’s sign, which is an upward movement of umbilicus when the patient is asked to get up from a supine position. This is due to a paralysis of lower abdominal wall muscles.
• The testing of abdominal wall muscles is recommended when suspecting thoracic discogenic pain syndrome. Right iliac fossa pain of flexion of the hip is seen in appendicitis which is an important differential. Eruption f a rash is seen in the dermatomal shingles. Trendelenburg sign is seen with the involvement of the superior gluteal nerve and subsequent pelvic instability.

Question 2

A 67-year-old female patient came to the emergency department with a history of unconsciousness two weeks ago, which reversed after a few hours following treatment. The initial CT scan of the brain was normal. Since then, she has been behaving oddly, complaining about the darkness in the room, not recognizing her family members, stumbling during walking, and making excuses for her behavior. An MRI brain was done, and it showed a bilateral occipital infarct. What is the probable diagnosis?

Answer 2

1. Riddoch syndrome
   2. Anton syndrome
2. Balint syndrome
3. Gerstmann syndrome

• Anton syndrome is also known as visual anosognosia. Here, the patient shows telltale signs of blindness but denies it.
• In Anton syndrome, the patient often takes the help of confabulation in the process of denial.
• It occurs due to damage to the bilateral primary visual cortex. The main cause of Anton syndrome is posterior cerebral artery stroke.
• Riddoch syndrome or Riddoch phenomenon describes a subtype of visual disturbance due to occipital lobe lesion. The affected patient solely can distinguish non-static objects in his or her blind field. Balint syndrome is composed of three major components of optic ataxia, ocular apraxia, and simultanagnosia. It might occur due to posterior parietal lobe lesions. Gerstmann syndrome is composed of four distinct parts, including the disturbance in the ability of writing, making mathematical calculations, finger identification, and making significant distinctions.

Question 3

A 54-year-old female presents to the trauma bay with an acute spinal cord injury. After initial resuscitation and stabilization of the patient, the provider begins a thorough review of her past medical history. Which of the following has the most significant impact on increasing her risk for decreasing bone mineral density in the long term?

Answer 3

1. A fracture from a ground-level fall after 50 years of age
   2. Early menopause
2. Bodyweight under 158 pounds
3. Hispanic race

• The risk factors for osteoporosis in at-risk populations remain the same when considering the spinal cord injury (SCI)-induced osteoporosis patient subgroup.
• Early menopause is a known significant risk factor for osteoporosis. Other risk factors for osteoporosis include increasing age, bodyweight under 128 pounds, smoking, family history of osteoporosis, white or Asian race, low levels of physical activity, and a personal history of a fracture from a ground-level fall or minor trauma after the age of forty.
• After an acute SCI patient is stabilized, multi-professional care must begin as soon as possible. It includes, but is not limited to, referring to a provider specializing in managing patients with bone mineral density deficiency.
• The initial two weeks after injury is the most vulnerable clinical period for rapid bone mineral density losses.

Question 4

A 16-year-old boy presents with bilateral sensorineural hearing loss and unsteady gait. His MRI brain revealed features of bilateral tumors arising within the internal auditory canal and compressing upon the cerebellum. His brother also had a history of being operated on for a posterior fossa tumor. What gene is implicated in the condition seen in the patient?

Answer 4

1. Neurofibromin
   2. Merlin
2. VHL gene
3. Rb gene

• Bilateral vestibular schwannomas are diagnostic of NF2.
• NF-2 is known as Merlin and acts as a tumor suppressor. Decreased production or function results in an increased likelihood of tumors of the central and peripheral nervous systems.
• Half of the patients with NF-2 have a de nova mutation in the merlin gene.
• Neurofibromin is implicated for Neurofibromatosis type 1. VHL is associated with hemangioblastomas.

Question 5

A female infant is born to a healthy mother via vaginal delivery. The initial exam shows a 3 cm x 5 cm cystic mass on the infant’s back. On careful evaluation, a skin and bone defect is the provisional diagnosis. The mother has a past history of delivery of a child with similar pathology 1 year ago. What is the estimated risk of the recurrence of similar pathology in a future pregnancy?

Answer 5

1. 1%
2. 3%
   3. 10%
3. 15%

• The clinical presentation in the child is highly suggestive of a spinal dysraphism.
• This is the second occurrence of the entity following the delivery of the child to the mother.
• The estimated recurrence risk after two such pregnancies is approximately 10%.
• The empirical recurrence risk after one affected pregnancy is approximately 3%.

Question 6

A 31-year-old man with a past medical history significant for spinal fusion of his L2-L4 vertebra secondary to a traumatic fracture following a motor vehicle collision presents to the office for further evaluation of his chronic back pain. He was diagnosed with spinal stenosis five years ago. His car accident occurred four years ago but has been getting worse over the last year. He was recently evaluated for depression by his primary care provider, but the assessment was negative for depression. He complains of a dull ache in his back that is constant. He denies any numbness, burning, or shooting pains in his back. The severity of his pain is 7/10. He states his low back is tender to even light pressure, where even tight-fitting clothing can cause him pain. He has been on chronic opioid therapy since the accident, requiring 60 morphine equivalents daily. Acetaminophen and NSAIDs do not help with his pain. He denies any bowel or bladder incontinence. However, he constantly worries about his pain and how it will get worse. What aspect of this patient’s pain is most consistent with a centralized process to his pain?

Answer 6

1. Dull nature of the pain
   2. Allodynia
2. Chronic opioid dependence
3. Pain catastrophizing

• Pain being experienced from non-painful stimuli is allodynia this is a centralized process. When assessing pain it is important to be cognizant of signs of centralized pain.
• This patient is also experiencing mildly painful stimuli experienced as severe pain (hyperalgesia). This is also an important clinical sign on the assessment for centralized pain.
• Centralized pain is a maladaptive form of pain where a lower threshold is needed to experience pain. Worsening pain over time may be a sign of his pain becoming centralized. It is important to the aspect of pain assessment if the pain has gotten worse over time.
• Another reason for the worsening of this patient’s pain over time is tolerance to his chronic opioids. It is important to determine during your pain assessment if the patient has required recent changes to his pain management.

Question 7

A 17-year-old female is brought to the hospital following a motor vehicle collision. While determining her motor score, she is found to have abnormal flexor posturing. Fifteen minutes later, she develops extensor posturing involving both her upper and lower limbs. What is the most likely pathological basis for the characteristic posturings observed in the patient following the traumatic brain injury?

Answer 7

1. Uncal herniation
2. Subfalcine herniation
   3. Transtentorial central herniation
3. Tonsillar herniation

• Central herniation of the brain can lead to abnormal flexor or extensor posturing.
• Abnormal posturing occurs in transtentorial herniation. Injury sparing the rubrospinal tract causes flexion of the upper limbs with an extension of the lower limbs. Further herniation with the involvement between the red nucleus and the vestibulospinal tract causes extensor posturing of both the upper and lower limbs.
• Once there is the involvement of the medulla, there will be no motor response. The patient will also exhibit abnormal respiration.
• Tonsillar herniation leads to respiratory arrest due to the involvement of the medullary respiratory centers.

Question 8

A 40-year-old male presents to the emergency department after being involved in a motor vehicle collision. He escaped unscathed but complained of lower back pain since the event. His examination reveals no focal neurological deficit. An X-ray of the spine is performed. The X-ray shows an anterior translation of the L5 vertebrae over the S1 vertebrae. The distance of displacement is approximately 50% of the vertebral body length. Which of the following clinical findings is consistent with the radiological investigations in this patient?

Answer 8

1. Back pain on spine extension
2. Severe pain on light touch
3. A popliteal angle of 20 degrees
4. Back pain on spine flexion

• This patient has been involved in a motor vehicle collision. He complains of lower back pain but has no focal neurological deficit. The spine X-ray shows the anterior displacement of L5 vertebrae making the likely diagnosis of traumatic lumbar spondylolisthesis.
• Patients may complain of lower back pain or may present with symptoms of cauda equina compression. Back pain on extension of the spine often elicits pain. Extension of the spine places strain on the affected region and leads to a reproduction of pain.
• Single-leg hyperextension repeated extension and resisted back extension when prone are some of the maneuvers that can elicit back pain in individuals with spondylolisthesis. There may also be the tightness of hamstrings associated with back pain.
• No single examination finding is sensitive or specific for spondylolisthesis, and signs should be correlated with radiological evidence. Flexion of the spine usually does not cause pain. Tenderness on light touch indicates a more superficial process, such as spinous process apophysitis. The tightness of hamstrings and a popliteal angle greater than 50 degrees may be seen in individuals with higher-grade spondylolisthesis.

Question 9

A 17-year-old male diver presents for follow up in the spine clinic. The patient had a fatigue fracture noted between the L4-5 and L5-S1 facet joints on the right side, a year ago. The patient and family want to know if his injury is getting better or worse. Which of the following modalities best assesses the extent of cortical disruption and is best for assessment of healing with regards to this injury?

Answer 9

1. Plain film
   2. Computed tomography
2. Magnetic resonance imaging
3. Bone scan

• CT scan is the best modality for determining fracture size and extent and is the most appropriate modality for follow-up assessment of healing.
• CT has the downside of additional radiation exposure, which is particularly concerning in the pediatric and adolescent population.
• Bone scan is the best modality for detecting early pars defect.
• Similar to a bone scan, MRI can be useful for early detection of acute lesions by the presence of bone marrow edema on T2 weighted sequences.

Question 10

A 35-year-old woman presents to the clinic for a follow-up of epilepsy. She is taking three antiepileptic medications and still has frequent focal seizures several times a week. This has been affecting her quality of life and professional career. Which of the following is the next best investigation to help plan possible surgical treatment in this patient?

Answer 10

1. FDOPA PET scan
   2. FDG PET scan
2. Amyloid PET scan
3. FDG SPECT scan

• FDG PET scan is instrumental in the presurgical workup of medically refractory epilepsy.
• FDG PET and not SPECT can localize or lateralize the seizure onset zone (SOZ).
• FDG PET scan changes are also predictive of the severity of disease and changes in glucose metabolism postoperatively are associated with a better prognosis.
• FDOPA PET scan does not currently have a clear role in the presurgical workup of epilepsy. C11 methionine, a different amino acid PET scan, has been used successfully in delineating the SOZ in tuberous sclerosis patients.

Question 11

A 48-year-old woman undergoes transsphenoidal hypophysectomy. Her surgeon had not gone through her CT scans thoroughly before the surgery. Postoperatively, the patient’s vision is diminished on the right side. Presence of which anatomical variation is most likely to have caused this complication?

Answer 11

1. Pneumatisation of pterygoid base
   2. Sphenoethmoidal cell
2. Poorly pneumatised sphenoid
3. Sellar type of pneumatisation

• Sphenoethmoidal cell/Onodi cell is a posteriormost ethmoid cell pneumatising into the sphenoid sinus.
• It lies superolateral to the sphenoid sinus close to the internal carotid artery and optic nerve.
• It is identified as a cell superior to the ipsilateral sphenoid sinus, separated by a horizontal septation.
• Careful identification of this anatomical variant is vital as optic nerve may be exposed in this air cell.

Question 12

A 78-year-old man is being evaluated in the ICU. He was admitted two days ago for severe meningoencephalitis. The patient is not able to maintain a seated or lying position and is not a candidate for the Omaya reservoir. Which of the following is the most appropriate method for intrathecal antimicrobial therapy in this patient?

Answer 12

1. Lumbar puncture
   2. Cervical approach CSF retrieval
2. Thoracic approach CSF retrieval
3. External ventricular device for CSF retrieval

• One of the alternatives that you can evaluate when trying to start intrathecal therapies when lumbar puncture and ventricular access are contraindicated is suboccipital puncture access.
• Thoracic CSF retrieval is not recommended due to the anatomy of the spine in this segment. Suboccipital anatomy makes for a more direct and safe approach when considering intrathecal therapies.
• Also when positioning is an issue, as well as the cooperation of the patient, is null, the suboccipital puncture can give you control over the procedure and makes it safer for the patient.
• Omaya reservoir is a possible approach but is a more invasive procedure.

Question 13

A 42-year-old man is brought to the emergency following a motor vehicle collision. Neurological examination revealed more weakness in his bilateral upper limbs compared to that of his lower limbs. He also has a weak gag reflex. Which of the following is the most likely pathogenesis for such a characteristic neurological presentation in the patient?

Answer 13

1. Central cord syndrome
2. Traumatic syrinx
   3. Cruciate paralysis
3. Spinal epidural hematoma

• The patient has characteristic clinical features of cruciate paralysis.
• This characteristically occurs due to injury at the cervicomedullary region.
• The corticospinal fibers of the upper limbs decussate in the rostral pyramids compared to that of the lower limbs which decussate more caudally.
• There is characteristic involvement of the lower cranial nerves as well in sharp contrast to that of the central cord syndrome.

Question 14

A patient develops acute left hemiplegia involving the face more than the arm and leg. The suck and grasp reflexes and speech are preserved. Which cerebral vessel is involved?

Answer 14

1. Anterior cerebral artery
2. Vertebrobasilar artery
   3. Middle cerebral artery
3. Posterior cerebral artery

• Anterior cerebral artery strokes often affect the leg more than the arm or face.
• Middle cerebral artery strokes often affect the face and upper extremity. Speech is mostly a left hemisphere function.
• Posterior cerebral artery strokes present with visual field defects.
• Vertebrobasilar artery strokes are variable in presentation but often have crossed signs.

Question 15

A 79-year-old male with a past medical history of atrial fibrillation, arterial hypertension, and diabetes mellitus type 2 presents to the emergency room after suffering a ground-level fall yesterday night at a dinner party. The patient is neurologically stable with a blood pressure of 160/85 mmHg. However, he is complaining of headaches and the inability to hold objects with his right upper extremity. The head computed tomographic scan shows a large left acute subdural hematoma with a 1.2 cm shift of midline structures. A craniotomy is performed for hematoma evacuation. Sutures were removed the following week. Six weeks later, the patient returns to the emergency room with headaches, low-grade fever scalp swelling near the proximal margin of the wound. He has a normal neurological exam. Which of the following disorders would be of most significant concern?

Answer 15

1. Hydrocephalus
2. Recurrent subdural hematoma
3. Stroke
   4. Osteomyelitis

• A craniotomy is performed to drain intracranial hematomas. Osteomyelitis of the bone flap can occur and is usually associated with wound infection and subdural empyema. It occurs several weeks after a craniotomy.
• Complications of a craniotomy include seizures, stroke, coma, lethargy, hydrocephalus, wound infection, osteomyelitis, and air embolism.
• Once the craniotomy concludes, the bone is reattached in position with plates and screws. Pristine hemostasis should be obtained before closing the scalp.
• When the patient is under general anesthesia, effective communication between providers minimizes complications and unexpected events.

Question 16

An 80-year-old male involved in a motor vehicle collision with a positive loss of consciousness was ambulatory on the scene. He has no other past medical history. Computed tomography cervical spine reveals a C2 vertebral body fracture with 2 mm of posterior displacement. He is neurologically intact but hemodynamically unstable. Which of the following is the next best course of treatment?

Answer 16

1. Emergent surgery for fracture stabilization
2. Emergent surgery for neurogenic shock
   3. Rigid collar fixation
3. Immediate MRI of the cervical spine

• Type III odontoid fractures are usually considered stable and do not require emergent surgery.
• Odontoid fractures with dens displacement greater than 5 mm are considered surgical.
• Rigid fixation is the standard of care for type III fractures that have minimal to no displacement.
• MRI is warranted to evaluate the ligamentous complex however rigid fixation is priority.

Question 17

A 16-year-old patient sustains a severe head injury following a motor vehicle collision. His intracranial pressure (ICP) has been monitored by an external ventricular drain (EVD) placement. Despite keeping the patient intubated and sedated in mechanical ventilation, his ICP is persistently above 20 mm Hg. His serum electrolytes are normal, and serum osmolality is 330 mOsm/kg. The treating clinician plans to start medical therapy to manage his refractory cerebral edema. Which of the following is the most rational approach to managing the patient?

Answer 17

1. Hypertonic saline
2. Mannitol
3. Urea
4. Glycerol

• The use of hypertonic saline in the management of intracranial hypertension has shown to be of rapid onset, sustained as well as long-lasting effects with collateral improvement in cerebral perfusion as well.
• 3% hypertonic saline with a loading dose of 5 ml/kg and a maintenance dose of 2 ml/kg every six hours has shown to be highly efficacious as well as safe in managing refractory intracranial hypertension. A target serum sodium while administering 3% saline is 150 to 155 mEq/L, which roughly corresponds to a serum osmolality of 320 to 340 mOsm/kg.
• The occurrence of side effects such as central pontine myelinolysis and acute tubular necrosis with hypertonic saline is minimal in patients with serum osmolality of above 320 mOsm/kg and normal serum sodium values. A serum sodium level of 155 mEq/L (and osmolality of 320 mOsm/kg) is generally considered to be the safe upper limit for the administration of mannitol.
• Urea and glycerol have low efficacy in managing cerebral edema. Mannitol use leads to a high occurrence of rebound cerebral edema, renal failure, and electrolyte imbalance. Both hypertonic saline, as well as mannitol, have comparable all- cause mortality rates.

Question 18

A 32-year-old female patient presents to the hospital with left-sided eye pain and diplopia for the past three days. Her past medical history is suggestive of loss of pregnancy in the first trimester one year ago. On examination, her blood pressure is 140/90 mmHg, and heart rate is 88 bpm. Examination of her eyes reveals equal-sized pupils that are reactive to light and no proptosis. However, the left-sided eye is found to have deviated downward and outward, and it is unable to move laterally. Furthermore, there is hyperesthesia of the upper face on the left side. What is the most likely diagnosis?

Answer 18

1. Acute angle-closure glaucoma
   2. Cavernous sinus thrombosis
2. Mucor mycosis
3. Epidural hematoma

• The diagnosis of antiphospholipid syndrome (APLS) includes clinical and laboratory criteria. Obstetric medical history is an important element of the history if APLS is suspected. Arterial and venous thrombosis are typical manifestations of APLS.
• The most common sites of venous and arterial thrombosis are the lower limbs and the cerebral arterial circulation, respectively, but thrombosis can occur in any organ.
• This patient has a history of pregnancy loss and now presents with features indicative of cavernous sinus thrombosis, which is likely to be secondary to the prothrombotic state caused by APLS.
• Acute angle-closure glaucoma usually does not present with the constellation of neurological findings described in this case.

Question 19

A 28-year-old female presents with sudden onset right low back pain radiating to the right buttock, right posterior thigh, calf, and ankle. Symptoms started after she bent down to pick a heavy box at work. She reports severe pain that affects her sleep and ability to work and perform activities of daily living. Physical therapy seems to aggravate the pain. Examination shows intact strength and sensation and symmetric 2+ deep tendon reflexes. The straight leg raise test was positive on the right. She denies and bladder-bowel problems or saddle anesthesia. MRI of the lumbar spine was done and showed an L5-S1 Right paracentral disc herniation impinging the Right S1 nerve root. What would be the next best step in management?

Answer 19

1. Consider spine surgery consultation for lumbar discectomy.
   2. Consider a trial of lumbar epidural steroid injection.
2. Consider a lumbar sympathetic nerve block.
3. No other treatment is indicated at this time

• The patient’s presentation is most consistent with lumbar radiculopathy secondary to L5-S1 dis herniation. She experienced sudden onset right low back pain radiating to the Right L5-S1 dermatome with concordant MRI findings.
• Since the patient’s pain failed to improve with physical therapy and seems to significantly impair her function and quality of life, further treatment would be indicated.
• Her neurological examination is normal with no motor or sensory deficits. Therefore, the next best step would be a trial of lumbar epidural steroid injection.
• Surgical consultation should be considered sooner if any neurologic deficit is present.

Question 20

A 69-year-old man is brought to the emergency department after sustaining a ground-level fall. He is complaining of neck pain. Neurological examination is unremarkable. X-rays of the cervical spine demonstrate marginal syndesmophytes and kyphosis but no acute fracture. A cervical CT scan demonstrates a nondisplaced fracture through C5-6 disc space into the posterior bony elements of C5. Which of the following is the best initial treatment for this patient?

Answer 20

1. Halo vest for 6 weeks
2. Hard collar for 6 weeks
3. Posterior fusion and instrumentation C4-C7
   4. Posterior fusion and instrumentation C3-T1

• This patient has ankylosing spondylitis and is prone to cervical spine fractures from low energy trauma.
• Due to the long lever arm of the fused spine, fixation constructs should be long with multiple levels above and below the fracture to allow for less stress on the construct.
• Whether or not to go anterior and posterior is still debated in the literature. However, there is a higher rate with anterior fixation alone.
• The conservative treatment of these fractures in a collar will require neuromonitoring as they are at high risk of developing neurologic deterioration.

Question 21

A 25-year-old woman is brought to the emergency department (ED) with a brief sensory loss on the right side of the face and mild incoordination of the right upper extremity. Her examination done in the ED shows no residual deficits. The MRI indicates no infarct, but stenosis of the high-grade right-middle cerebral artery is found on the magnetic resonance angiography (MRA). The stenosis along with extensive hypertrophy and collateralization in the lenticulostriate vessels is confirmed on an angiogram. Her vitals shows blood pressure of 135/65mmHg, and her labs indicate a low-density lipoprotein of 109 mg/dL (reference range 100 mg/dL) and total cholesterol of 234 mg/dL (reference range 200 mg/dL). Which of the following is the most effective intervention for stroke prevention in this patient?

Answer 21

1. High-dose statin therapy
2. Aspirin
3. Endovascular stenting of the right-middle cerebral artery (MCA)
   4. Surgical bypass of the right MCA

• The sign and symptoms, along with the angiographic findings in this patient, are suggestive of Moyamoya disease (MMD).
• Moyamoya disease (MMD) is an isolated chronic, usually bilateral, vasculopathy of undetermined etiology characterized by progressive narrowing of the terminal intracranial portion of the internal carotid artery (ICA) and circle of Willis.
• Surgical revascularization is the only main treatment for MMD with deteriorating cerebral hemodynamics to improve the cerebral blood flow and prevent further strokes.
• Main indications for surgical revascularization are apparent cerebral ischemia, reduced regional cerebral blood flow, and decreased cerebral vascular reserve in perfusion studies. However, every case is evaluated separately as decisive factors may vary from case to case. Surgery is more beneficial for children since the pediatric form of MMD is usually rapidly progressive.

Question 22

A 73-year-old male presents to the clinic with chronic low back pain. He had undergone a lumbar facet block several times with positive results. How many levels of medial branch blocks should be done if the provider wants to block the facet joints between the third to fifth vertebras?

Answer 22

1. 5
2. 2
3. 3
   4. 4

• Each facet joint is innervated by two medial branches of the posterior ramus.
• One from the medial branch above, the other from the medial branch below.
• The medial branch of the posterior ramus can be blocked at the location near the origin of the transverse process.
• Medial branch block can help to reduce the pain related to facet arthropathy but may have to be done every three months.

Question 23

A 16-year-old woman presents with CSF rhinorrhoea. A lumbar drain is inserted for CSF rhinorrhoea. On day 4 of admission, she developed a high-grade fever, neck pain, and photophobia. On examination, neck rigidity is present and Kernig’s sign is positive. What is the most likely pathogen responsible for this presentation?

Answer 23

1. Neisseria meningitidis
   2. Streptococcus pneumoniae
2. Anaerobic bacteria
3. Herpes simplex virus

• Meningitis is the most common complication associated with and is seen in around 25-30% of the cases.
• Early warning signs include headache, photophobia, neck rigidity, positive kernig’s sign, and altered sensorium.
• In patients with evidence of meningitis, empirical antibiotics must be started, followed by culture-based antibiotics after microbial culture and sensitivity is available.
• The most common pathogens include Streptococcus pneumoniae and Hemophilus influenzae. Polymicrobial and anaerobic infections can be observed in cases with penetrating injuries.

Question 24

A 49-year-old woman is being evaluated for endoscopic transsphenoidal hypophysectomy for a pituitary tumor. A recent MRI shows suprasellar extension of the mass. Which of the following is the most appropriate approach for surgery in this patient?

Answer 24

1. Transclival
   2. Transtuberculum
2. Transpterygoid
3. Transcribriform

• This question focuses on the understanding of anatomical landmarks in the sphenoid sinus and adjacent skull base. A suprasellar extension may necessitate further exposure superiorly from the sellar bone.
• Sulcus chiasmaticus, tuberculum sellae, and planum sphenoidale are arranged, inferior to superior, in relationship to the sellar prominence.
• Hence superior exposure would require a transtuberculum or a transplanum-transtuberculum approach.
• Clivus is inferior to the sellar prominence. The pterygoid process and cribriform plate are lateral and anterior to the sphenoid sinus, respectively.

Question 25

A 35-year-old man is diagnosed with acute hydrocephalus due to tuberculous meningitis, and antitubercular therapy is started. He is admitted to the neurosurgery intensive care unit following external ventricular drain (EVD) placement from Kocher point and is showing clinical improvement. During the second day of admission, the patient inadvertently pulls out his EVD drain. The treating clinician immediately places a new EVD from the same point. There is clear egress of cerebrospinal fluid (CSF) in the EVD bag. What is the most appropriate next step in management?

Answer 25

1. Repeat CT head to ensure proper EVD placement
   2. Send CSF for culture and sensitivity
2. Plan for ventriculoperitoneal (VP) shunting
3. Plan for endoscopic third ventriculostomy (ETV)

• The accidental removal of an external ventricular drain (EVD) has a reported incidence of only 0.4 %. It is a serious adverse event with high risks for intraventricular bleeding and ventriculitis.
• The incidence of ventriculostomy-related infection ranges from 0-30%. However, the mortality from ventriculitis has been reported to be as high as 40%.
• It is critical to send the cerebrospinal fluid (CSF) for culture, initiate broad-spectrum antibiotic coverage, and modify the antibiotics based on the culture and sensitivity results.
• CSF diversion procedures such as VP shunting and endoscopic third ventriculostomy (ETV) should be performed only after ruling out microbiological evidence of ventriculitis in this patient.

Question 26

A 58-year-old man presents to the clinic with clumsiness of the right hand and difficulty in walking. The physical examination reveals a positive Hoffmann sign and guttering of intermetatarsal space. MRI shows cervical spondylosis and spinal canal stenosis at two levels. Lateral flexion radiograph reveals normal minimal kyphosis, which is correctable on extension radiographs. What is the most appropriate management strategy for this patient?

Answer 26

1. Decompression and anterior fusion
   2. Decompression and posterior fusion
2. Laminectomy and decompression
3. Conservative management

• The above-mentioned scenario reveals significant cervical spondylosis at two levels of the cervical spine.
• Decompression with posterior fusion is the ideal treatment of choice for this patient.
• Flexion and extension radiographs are required to assess the instability and correctable deformity.
• Decompression and laminectomy without fusion lead to poor results.

Question 27

A 65-year-old man is brought by his son for sudden onset nausea, vomiting, and confusion. His son reports that his father has been diagnosed with Alzheimer disease and takes medication for it and hypercholesterolemia, arthritis, and gout. He also had treatment for basal cell carcinoma about ten years ago and uses inhalers when needed for bronchiectasis. His son also mentions that his father was taken to the hospital with similar symptoms a few months ago, but the outcome from that admission is unknown. A plain CT head reveals a heterogenous, hyperdense hemorrhagic lesion in the right frontal lobe with surrounding edema and midline shift. Considering the pathogenesis of this patient’s suspected diagnosis, what aspect of his history has most likely increased the risk of his current presentation?

Answer 27

1. Alzheimer disease
2. Hypercholesterolemia
3. Bronchiectasis
4. Inhaler intake

• The pathogenesis of Alzheimer dementia includes the formation of plaques of amyloid protein within the brain known as cerebral amyloid angiopathy (CAA), which is also a risk factor for lobar intracerebral hemorrhage (ICH).
• CAA is due to the deposition of beta-amyloid protein in cerebral cortical blood vessels (rarely in the basal ganglia and brainstem), seen most commonly in the population above 55 years of age.
• The apolipoprotein E (ApoE) genotype is thought to impact the pathophysiology of CAA but is not a sensitive test to diagnose the disease. CAA increases the risk of lobar ICH significantly, and imaging often reveals hemorrhages of varying ages, which may be seen as heterogeneously attenuating lesions.
• Low cholesterol, when associated with hypercoagulable states or hypertension, can be a risk factor for ICH.

Question 28

A patient presents to the clinic with a complaint of back pain. He gives a history of a fall from stairs one week ago. Now he has developed stiffness in the lumbosacral region and numbness in the feet. The attending clinician advises MRI of the lumbosacral region. The attending clinicians should keep in mind that surgical intervention for the initial management of such patients should be considered if a patient is found to have which of the following?

Answer 28

1. Severe pain
   2. Lower extremity motor deficit
2. Symptoms that have lasted less than 3 months
3. Difficulty completing activities of daily living

• While even severe pain may be expected to improve with multimodal nonoperative treatment, the presence of motor deficits is less amenable to conservative management.
• As motor deficits resulting from direct nerve root compression by a lumbosacral disc injury may result in permanent weakness and the resulting disability, surgery should be considered as an early treatment option when evaluating a patient with lumbosacral disc injury and associated focal weakness.
• Without formal adherence to nonoperative treatment such as oral NSAIDs, physical therapy and epidural injections, the duration of symptoms alone is not an indication to proceed with surgery prolonged pain does not have the potential for permanent disability seen with motor deficits.
• In the absence of motor deficits, physical impairment is not an indication to proceed with surgical intervention initially when managing lumbosacral disc injuries. Nonoperative treatment such as oral NSAIDs, physical therapy, and epidural injections should be trialed with the expectation that they may improve functional status.

Question 29

A 1-year old boy is brought to the clinic due to an abnormal midline forehead bony ridge. There is no family history of a similar disease. The developmental milestones are normal for his age. A 3D computed tomographic scan shows frontal bones with a triangular shape, hypotelorism, anterior displacement of the coronal sutures, widening of the posterior parietal regions, pterional constriction, and flattening of the supraorbital ridges with lateral orbital hypoplasia. What is the most appropriate management strategy for this patient?

Answer 29

1. Conservative management
2. Head helmet therapy
3. Endoscopic surgery
   4. Open surgery

• Early operative treatment is recommended to provide the best possibility for the brain to expand and produce a normal configuration of the skull. Surgery goals are to remove the bony ridge of the metopic suture, advance both orbits and the frontal bones, achieve a rounder forehead contour, and prevent the psychosocial impact and neurodevelopmental delay.
• Operative treatment can be endoscopic or open. This child is already one year of age. Endoscopic technique is best used before 3 to 4 months of age due to the skull’s pliability. Thus, open surgery is recommended.
• In those cases where cranial reconstruction is required, a bifrontal craniotomy is performed to reconstruct the anterior cranial vault, including the lateral portions of the sphenoid wings to allow brain expansion.
• If the deformity is minimal or there is only a bony ridge without hypotelorism, a more conservative approach can be used; however, the child should be followed for a minimum of 12 months of age to assess and corroborate adequate cranial growth. Clinical evaluations and family discussions regarding neuropsychological development are engaged. A head helmet is used on the patient on the fifth postoperative day after endoscopic surgery. It is used for the next 10–12 months to directed cranial growth by allowing cranial expansion in recessed areas of the skull.

Question 30

A 76-year-old woman with a history of achondroplasia presents to the clinic with weakness and pain in the lower back and intermittently in the legs for the past 5 months. A nerve conduction study with needle electromyography is ordered. Which of the following sets of findings is most likely to be seen in this patient?

Answer 30

1. SNAP amplitudes are normal, CMAP amplitudes normal, and abnormal spontaneous potentials on needle EMG
2. SNAP amplitudes are normal, CMAP amplitudes increased and abnormal spontaneous potentials on needle EMG
3. SNAP amplitudes are increased, CMAP amplitudes normal and abnormal spontaneous potentials on needle EMG
4. SNAP amplitudes are increased, CMAP amplitudes increased and abnormal spontaneous potentials on needle EMG

• The majority of the patients have normal sensory and mother nerve conduction studies. However, needle EMG is possible in cases with radiculopathy but not essential during a spinal stenosis study. If there is a significant narrowing of the vertebral formanina and root compressions in the acute setting, you may find fibrillations and positive sharp waves at different levels bilaterally.
• In a patient with spinal stenosis, motor nerve conduction studies and amplitudes are usually normal. Distal latencies should also be normal as the distal aspect of the nerve is not disturbed. However, if the disease has progressed to the point where axonal damage has occurred, you will see a decrease in amplitude of the CMAP on nerve conduction studies.
• In a patient with spinal stenosis, sensory nerve conduction studies and amplitudes are usually normal. This occurs because the sensory fibers travel through the dorsal root ganglion, which is located outside the spinal canal.
• For the needle EMG portion of the exam, it is essential to test multiple paraspinal levels bilaterally and multiple myotomes in both extremities. In spinal stenosis, often, there are findings of bilateral multilevel nerve root involvement, if there is root involvement.

Question 31

A 54-year-old female with a history of low back pain for many years and frequent falls presents to her primary care office due to an increase in the back pain, which is now radiating to the right leg. Pain starts at the right buttock and goes lateral on the thigh and anterior in the leg down to the big toe. On exam, she has a positive straight leg raising on the right leg. Knee jerk and ankle jerk are normal, but she can not dorsiflex the big toe. She also has a completed foot drop. Which type of gait disturbance will she present?

Answer 31

1. Steppage gait
2. Waddling gait
3. Hemiparetic gait
4. Myelopatic gait

• Steppage gait produces an initial contact with toes (foot drop). The heel is unable to strike first.
• Steppage gait is caused by ankle dorsiflexion weakness. A herniated disc at L4-L5 will compress the L5 root and create radiculopathy affecting the muscles and producing dorsiflexion of the ankle.
• Treatment for steppage gait is hinged or posterior leaf spring ankle-foot-orthosis (AFO) and electrical stimulator. Sometimes surgery can reverse foot drop.
• Waddling gait or toe walking is caused by proximal muscle weakness.

Question 32

A 3-year-old girl was brought to the hospital by her grandmother, who looked very concerned. The child fell from her bed in the morning and was very irritable for a couple of hours following the injury. The grandmother informed that the child held her neck “stiff” for the initial hour, after which she was fairly comfortable. There was no episode of loss of consciousness or vomiting. The general physical and neurological examination of the child was normal. The child was playful, and it was decided to obtain a CT scan of the head. The CT scan reveals no brain injury. However, there is a bilateral discontinuity on the arch of the atlas (C1), just anterior to the facet. What is the next step in management?

Answer 32

1. Reassurance
2. Discuss the concern for a major cervical injury with the grandmother and advise CT and MRI studies of her cervical spine
3. Skull traction, followed by surgical stabilization
4. Halo vest application

• Three ossification centers develop in the immature atlas one for the anterior ring and one for each posterior neural arch. These ossification centers appear at one year of age.
• The connection between anterior and posterior arches is composed of neurocentral synchondrosis, which fuses at 7 years of age. The posterior arch usually closes by three years of age.
• The pattern of cervical fractures in children younger than 10 years is much different from older children and adults.
• Most of the cervical spine fractures in young children occur between occiput and C2 due to large head size and relative hypermobility.

Question 33

A 17-year-old boy is brought to the emergency department with head trauma after crashing in his skateboard. He has a minimally depressed frontal bone fracture that includes the anterior and posterior sinus walls. Two weeks later, the patient presents to the same hospital, and the mother explains that since the accident, his forehead has grown larger, warmer, and more tender. The patient also complains of subjective fevers, frontal headaches, and mild nausea. What is the most likely causative organism of this patient’s condition?

Answer 33

1. Pseudomonas aeruginosa
2. Fusobacterium
3. Streptococcus pneumoniae
   4. Staphylococcus aureus

• The condition described is a Pott’s puffy tumor which is osteomyelitis of the anterior table of the frontal sinus with a subperiosteal abscess. It is a complication of frontal sinusitis that is most commonly seen in young adults due to a more extensive network of diploic veins. The rapid diagnosis for fast treatment of this condition is crucial for optimal outcome and decreases the risk of development of complications such as intracranial extension via erosion of the posterior table of the frontal sinus. Studies have demonstrated that the best strategy for the management of Pott puffy tumors is the combination of medical and surgical treatment to prevent further complications and improve morbidity and mortality.
• Once the patient arrives and diagnosis is suspected, the patient should be admitted and started on broad-spectrum IV antibiotic, IV hydration, analgesia, and rapid coordination for imaging studies. A moth-eaten pattern of bone destruction is characteristic on imaging.
• Broad-spectrum IV antibiotics should be started as soon as the diagnosis is suspected. Coverage should be provided for the most common pathogens, including gram-positive and anaerobes. It is important to choose antibiotics that have adequate blood-brain barrier penetration for central nervous system coverage. Choices include penicillin or vancomycin, 3rd generation cephalosporin, and metronidazole. Once the culture has a final result, guide antibiotic therapy for that specific pathogen.
• While many Pott puffy tumors are polymicrobial, the most common single species are Staphylococcus aureus.

Question 34

A 66-year-old man with chronic axial lower back pain for two years is undergoing basivertebral neurotomy. There was no leg pain, no bowel or bladder incontinence or retention, and no motor or sensory changes. After the procedure, the patient does well, and on a 4-week follow-up, the patient is doing well with marked improvement in function and reduced pain and opioid utilization. Which of the following findings is most likely to have been seen in this patient’s pre-procedure MRI?

Answer 34

1. Lumbar L4-5 spondylolisthesis
2. One-eye owl sign with pedicle destruction
3. 50% reduction of the anterior vertebral body
   4. Modic changes type I or type II

• Based on this patient’s history and exam findings, a basivertebral nerve ablation procedure is indicated, and MRI diagnostic studies usually reveal Modic Type I and/or Modic type II changes. These are related to vertebral endplate changes with inflammation, edema, disruption, and/or fissuring, as well as fibrovascular bone marrow changes and fatty bone marrow replacement.
• Basivertebral nerve (BVN) ablation targets neurotomy (nerve destruction via radiofrequency ablation) of the BVN, which is responsible for carrying nociceptive input from damaged vertebral endplates, often seen in MRI as Modic changes type I and type II.
• BVN ablation is clinically indicated to treat chronic axial low back/vertebral pain refractory to six months of conservative treatment in the setting of Modic changes (type I and type II). Modic changes are seen on MRI as fibrovascular bone marrow changes (hypointensive signal for Modic type I changes); and fatty bone marrow replacement (hyperintensive signal for Modic type II changes).
• Pedicle destruction, compression fracture, and spondylolisthesis are not structural pathologies treated by BVN neurotomy.

Question 35

A 65-year-old female with a known history of multiple stable compression fractures of the spine returns to the clinic for an annual check-up. Upon review of systems, the patient admits to progressively worsening dyspnea and dizziness. Physical examination reveals worsening thoracolumbar curvature. However, motor and neurologic findings remain normal. Which of the following is the next best step in management?

Answer 35

1. Echocardiography
2. Spinal cord decompression
   3. Pulmonary function testing
3. CT scan of the chest

• Pulmonary dysfunction can include both obstructive and restrictive pulmonary changes.
• Physical examination should include a thorough inspection of symmetry, spinal alignment, flexibility, and work of breathing.
• Studies have shown a relationship between increased Cobb angle and poor performance on pulmonary function testing.
• Dizziness in this scenario may be secondary to comprised respiratory status. Therefore pulmonary causes should be ruled out before a neurology referral.

Question 36

A 25-year-old patient was involved in a motor vehicle accident and suffered a traumatic brain injury with his presenting Glasgow Coma Scale score of 6 out of 15. Upon painful stimulation over his supraorbital ridge, he elicits abnormal flexion of his upper extremities with an extension of his lower limbs. Which is the anatomical region responsible for such motor response seen in the patient?

Answer 36

1. Corticospinal tract
   2. Rubrospinal tract
2. Vestibulospinal tract
3. Extrapyramidal tract

• The description is typical of an abnormal flexion response equivalent to a motor score of 3.
• The rubrospinal tract is responsible for mediating flexion of upper limbs and extension of the lower limbs.
• The flexion of upper limbs indicates the location of the traumatic insult to be above the anatomic location of the rubrospinal tract.
• The vestibulospinal tract mediates the extension of both upper and lower limbs. The corticospinal tract governs voluntary motor functioning.

Question 37

A 65-year-old male presents in the emergency department with the complaint of pain in the cervical region and pain in the paraspinal region after he fell from a ladder. On examination, there is an asymmetry in the neck position, tenderness over the spinous process of the axis, and positive Sudeck’s sign. Which radiological investigation will help in confirming the diagnosis?

Answer 37

1. Computed tomography
2. Ultrasound
3. Open mouth anteroposterior cervical plain film radiograph
   4. Lateral cervical plain film radiograph in maximum flexion and extension

• The patient has C1-C2 instability, also called atlantoaxial instability. Lateral flexion-extension views are a dynamic study that shows the degree of displacement between vertebrae in the sagittal plane.
• Increased motion at the C1-C2 level can lead to vertebral artery occlusion, ischemia of the brainstem and posterior fossa structures, resulting in seizures, syncope, vertigo, visual disturbances and even sudden death after minor trauma.
• Surgery is usually indicated in patients who have more than 5 mm of translation in flexion and extension X-rays.
• Open mouth anteroposterior cervical X-Ray is not the proper incidence to detect anteroposterior C1-C2 instability. It reflects mediolateral instability, and spinal cord compression is less probable to occur under these circumstances. As with CT, MRI does not reflect the degree of instability between two vertebrae.

Question 38

A 28 years old male presents to the trauma bay with epistaxis and nasal deformity after a motor vehicle collision. Pt is alert and complains of severe headache and facial pain. Vital signs are HR = 110/min, BP = 116/80 mmHg, SpO2 = 99% on room air. Pt is assessed and sent for stat head and maxillofacial CT scan. Imaging reveals acute nasal bone and cribriform plate fractures. No intracranial hemorrhaging is identified. Rhinorrhea is sent to the lab and tests positive for beta two transferrin. What is the most likely management plan for this patient’s injury?

Answer 38

1. Conservative treatment with observation
2. Subcranial endoscopic repair
3. Open surgical repair
4. Discharge with outpatient follow up

• Most cerebrospinal fluid leaks from cribriform plate fracture resolve spontaneously.
• While conservative treatment is usually the best choice, the patient warrants observation to ensure resolution.
• Conservative treatment is preferred for patients who present with a GCS > 8 without other significant intracranial pathology.
• If the cerebrospinal fluid leak persists for greater than 7 days, surgery should be considered due to an increased risk of morbidity and mortality.

Question 39

A 32-year-old male patient was doing work in his backyard, and while cutting a branch, the electric saw jumped off the branch and made a laceration on his left arm on its lateral aspect. He controlled the bleeding with pressure but noticed that he could not dorsiflex the wrist. He went to his local emergency room, and the laceration was cleaned, but the radial nerve was found injured. The wound was closed, but the nerve was not repaired as there were no specialists in the clinic. He is referred to a neurosurgeon and a physiatrist. After four weeks, he goes to receive physical therapy. Which is the next best step in the management of this patient?

Answer 39

1. Start physical therapy to avoid muscle atrophy
2. Observe for 3 months for evidence of reinnervation
3. Send immediately to a neurosurgeon for nerve repair
   4. Perform needle electromyography

• Electromyography (EMG) is most useful after a two week to three-week delay to permit denervation changes to occur in the affected muscles. In a complete neurapraxia lesion, needle EMG will show no motor unit action potentials (MUAPs) under voluntary control, but fibrillations are not present. In complete lesions, the appearance of fibrillations and positive sharp waves is time and length-dependent; they do not appear for a number of days after the injury. In proximal muscles, they appear after 10 days to 14 days and in distal muscles after 3 weeks to 4 weeks. The presence of MUAPs by EMG examination indicates that reinnervation is occurring.
• The EMG is more sensitive than the physical examination for detecting early reinnervation, so the return of MUAPs on needle examination in the muscle closest to the injury site is typically the first evidence of reservation.
• Neurotmesis is the complete disruption of the nerve and nerve sheath. Recovery is unlikely without surgical intervention as the nerve axons will unlikely grow. For optimal nerve regeneration, nerve stumps must be precisely aligned without tension and repaired atraumatically with minimal tissue damage and a minimal number of sutures.
• Blunt transection repairs are usually delayed for 3 weeks to 4 weeks, at which point the nonconducting fibrotic segment of both stumps is appreciable and can be adequately resected before repair. Physical therapy can assist with some improvement of wrist function using compensatory techniques, stretching, and orthotics.

Question 40

A 27-year-old male patient presents to the clinic with complaints of tingling and burning pain in the right hand, which was amputated three weeks ago. He also says that his right hand feels shorter and is in a distorted and painful position. He also complains of increased pain when he goes out in the cold. Which of the following is the appropriate treatment in patients with this condition and a positive ketamine trial?

Answer 40

1. Phenytoin
   2. Amantadine
2. Methadone
3. Nerve stimulation

• The sign and symptoms in this patient are suggestive of phantom pain. Treatment should be started when patients have phantom pain and a positive lidocaine trial.
• A patient with phantom pain and a positive ketamine trial should begin taking amantadine.
• Pharmacological techniques often are used in conjunction with other treatment options. Doses of pain medications needed often decrease when combined with other techniques but rarely are completely discontinued.
• Tricyclic antidepressants and sodium channel blockers often are used to relieve chronic pain and in an attempt to reduce phantom pains. Opioids, ketamine, calcitonin, and lidocaine may relieve pain.

Question 41

A 65-year-old woman presents to the office with two months of neck pain radiating into her left arm and is progressively worsening. She denies any trauma and does not recall any inciting event. Examination reveals diminished sensation along the left medial forearm. Finger abduction strength is 4/5 on the left and 5/5 on the right. Biceps, brachioradialis, and triceps reflexes are 2/4 bilaterally. Spurling’s test is positive on the left. Hoffman’s test is negative bilaterally. Which of the following cervical level is most likely affected in this patient?

Answer 41

1. C5-C6
2. C6-C7
3. C7-T1
   4. T1-T2

• This patient is demonstrating signs of a chronic disc herniation with a gradual development of symptoms without an inciting event.
• Her neurologic examination is suggestive of T1 radiculopathy.
• T1 radiculopathy will have normal upper extremity reflexes.
• T1 radiculopathy will demonstrate diminished sensation at the medial forearm and a decreased strength of the finger abductors.

Question 42

An 8-year-old girl is being evaluated for a suspected brain tumour. She has a persistent, worsening headache with blurred vision and papilloedema on fundoscopy. An MRI head shows a posterior fossa tumour focused within the midline of the cerebellum, which has a large cystic component and an avidly enhancing nodular mural. Following a biopsy, the pathologist reports long bipolar cellular process with a low to moderate cellularity and multinucleated giant cells whose nuclei are located peripherally. The tumour is IDH mutant negative, BRAF and GFAP positive. What is the most appropriate management strategy for this patient?

Answer 42

1. MRI whole neuroaxis, surgical resection and radiographic surveillance
2. Surgical resection with postoperative radiotherapy
3. Radiotherapy alone
4. Surgical resection, radiotherapy, and chemotherapy with radiographic surveillance

• The radiographic and histological features are suggestive of pilocytic astrocytoma—particularly the long bipolar cellular process, cystic component, and nodular mural.
• These tumors are low grade and curative on surgical resection. Radiotherapy and chemotherapy are not routinely used.
• Children with posterior fossa tumors require whole neuroaxis imaging to assess for drop-metastasis.
• Patients with posterior fossa tumors often present with obstructive hydrocephalus. Symptoms include headache, nausea and vomiting, blurred vision, and papilloedema.

Question 43

A 45-year-old male presented with progressive weakness in his legs. His neurological exam shows a grade 4 out of 5 weakness in his legs and sensory level around his umbilicus. A magnetic resonance imaging scan of the spine shows a centrally located tumor within the dorsal cord from D5-D10 levels and causing cord expansion. It has a defined border with the cord. What is the treatment of this lesion?

Answer 43

1. Surgical excision
2. Radiotherapy
3. Chemotherapy
4. A biopsy followed by radiotherapy

• The patient is having an intramedullary tumor.
• The radiological features are suggestive of ependymoma. Ependymomas often are located centrally within the spinal cord leading to symmetric expansion, occupy the whole width of the cord, and enhance diffusely with a well-defined border.
• Gross total resection is the treatment modality for ependymoma.
• Astrocytomas tend to be positioned more eccentrically, can be non-enhancing or have an enhancing nodule or large satellite cysts, and usually, do not have a well-defined border.

Question 44

A 20-year-old male patient with no significant previous medical history presents with pain in the upper cervical region, with headache and cervical range of motion limitations in bilateral flexion, extension, and rotation movements. He woke up with discomfort, and throughout the day, increasingly felt more pain and further restriction of movement. The previous day he practiced Jiujitsu / JJB (combat sport) in which he felt a slight discomfort after strangulation, having continued training regularly. In the evaluation, there are limitations and pain to the touch in the anterior and posterior region of the neck. The Sharp-Purser test is positive. Which of the following may be present in this patient?

Answer 44

1. Sub-occipital contracture
   2. Subluxation of the atlas relative to the axis
2. Stress
3. Metabolic alteration

• The Sharp-Purser test has to be carried out with extreme caution. It determines the subluxation of the atlas relative to the axis.
• The examiner places one hand contacting the patient’s forehead, while the thumb of the other hand stabilizes the spinal process of the axis. The patient is then instructed to slowly flex the cervical spine, during the movement, the examiner presses in the opposite direction with the palm on the forehead. The test is considered positive if the examiner feels posterior sliding of the head along with patient pain.
• If the transverse ligament is responsible for maintaining the position of the odontoid process relative to C1 is affected, C1 will perform an anterior translation (subluxation) with respect to C2 during flexion.
• The muscles of the cervical spine ensure stability and mobility of the head.

Question 45

A 4-year-old male child is brought to the outpatient department with persistent nausea, vomiting for the past three months. The child complains of occasional severe headaches and is malnourished. On examination, there is no neurological deficit, but the child has papilledema. Magnetic resonance imaging of the brain shows an intensely enhancing mass in the left lateral ventricle and hydrocephalus. Which of the following viruses is most likely to be associated with this lesion?

Answer 45

1. Human immunodeficiency virus 1
2. 2. Human immunodeficiency virus 2
      3. 3. Simian virus 40
3. Human herpesvirus

• Choroid plexus papilloma is most commonly in a lateral ventricle in children and in the 4th ventricle in adults.
• In children, it can cause hydrocephalus.
• Studies have shown that Simian virus (SV) 40 has an association with the occurrence of choroid plexus tumors.
• BK virus and John Cunningham (JC) viruses have also been implicated.

Question 46

A 30-year-old man has been brought to the emergency department with the accidental firing of a nail gun nail into his head. He has no significant past medical history. His clinical examination has been performed and he is fully conscious and oriented. There is no neurological deficit. The nail is stuck to the left pterional region with mild oozing from the surrounding wound. What should be the next step in his management?

Answer 46

1. X-ray skull
2. Plain computed tomogram (CT) scan of the head
   3. Plain CT scan of the head with CT angiogram
3. Magnetic resonance imaging (MRI) scan of the head with MR angiogram

• The patient has a penetrating head injury.
• The nail is stuck to the pterion and hence there is a chance of injury to the main blood vessels at the skull base. The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join together. It is located on the side of the skull just behind the temple.
• Hence this patient needs an angiogram along with a CT scan head.
• MRI is contraindicated in this patient due to the presence of a metallic foreign body.

Question 47

A 40-year-old man is brought in with altered mental status. The patient was found outside his house and was minimally responsive. No past medical history is known. His vital signs show oxygen saturation 98% on room air, respiratory rate 18 per minute, heart rate 43 bpm, which appears sinus on the monitor, blood pressure 120/70 mmHg, and temperature 98 F. On examination, his Glasgow coma scale (GCS) is 9. His right leg is mottled, has no spontaneous movement, and a pulse cannot be palpated. He has punctate burns on the bottom of the foot. A further skin examination reveals a rash on his back that is in a ferning pattern. What is the most likely cause of the findings in his leg?

Answer 47

1. Stroke
   2. Keraunoparalysis
2. Intracranial hemorrhage
3. Arterial thromboembolism

• A lightning injury should be suspected in this patient, even in the absence of a definite history of lightning exposure.
• The rash is characteristic of Lichtenberg figures, which are pathognomonic for these injuries.
• Keraunoparalysis is a well-known phenomenon in victims of a lightning strike. It causes transient vasospasm, which can result in pulseless and paralyzed extremity.
• A stroke and intracranial hemorrhage should be considered in patients with altered mental status. However, in this case, it would not adequately explain the physical examination findings.

Question 48

Which of the following patients is a candidate for mannitol?

Answer 48

1. A 27-year-old female with oliguria secondary to severe dehydration
   2. A 55-year old female with refractory intracranial hypertension after a motor vehicle collision with significant long-bone fractures
2. A 63-year-old male with anuria and fluid overload
3. A 72-year-old male with increased intraocular pressure, severe congestive heart failure with an ejection fraction of 10% and severe hyponatremia

• Severe dehydration is a contraindication to mannitol as mannitol is a diuretic.
• Mannitol is FDA approved to treat increased intracranial pressure, increased intraocular pressure which is not responsive to other treatments, the oliguric phase of acute renal failure and to help increase diuresis of toxic materials.
• Anuria is a contraindication to mannitol as mannitol is a diuretic and the patient must be able to produce urine for it to work.
• Severe heart failure and significant electrolyte abnormalities are contraindications to mannitol as will increase the circulating plasma volume by increasing the intravascular water content and can worsen heart failure and electrolyte abnormalities.

Question 49

A 19-year-old woman presents with a five-month history of lower back pain. The patient is a professional ballet dancer. She also says she has been uncomfortable while walking. A lateral x-ray of her lumbar spine shows grade 4 lumbosacral spondylolisthesis. Which of the following muscles would most likely be weak on examination?

Answer 49

1. Quadriceps
2. Tibialis anterior
3. Tibialis posterior and gastrocnemius
   4. Extensor hallucis longus

• Isthmic spondylolisthesis is most common in an adolescent at L5/S1 level; hence most commonly affected root is L5 (exiting under L5 pedicle), which supplies extensor hallucis longus and hip abductors. On examination, one can expect reduced power of big toe extension.
• L5 nerve root supplies extensor hallucis longus; hence this patient would present with weakness of great toe extension.
• Grading of lumbosacral spondylolisthesis is described in the Meyerding classification. Grade 4 correlates with 75% to 100% of the vertebral body forward slip and is likely to cause neurological symptoms.
• Different nerve roots supply quadriceps, tibialis anterior, tibialis posterior, and gastrocnemius.

Question 50

A 24-year-old man is brought to the hospital after a motor vehicle collision. He was on a motorbike without a helmet and hit the back of his head. In the emergency department, he is noted to have a Battle sign and ecchymosis on his occiput. He is noted to have an immediate complete right-sided facial nerve palsy with electroneurography (ENoG), demonstrating a greater than 90% degeneration within six days. What is the most likely type of fracture/associated hearing loss?

Answer 50

1. Left-sided otic capsule-sparing fracture with sensorineural hearing loss
   2. Right-sided otic capsule disrupting fracture with sensorineural hearing loss
2. Right-sided otic capsule disrupting fracture with conductive hearing loss
3. Left-sided otic capsule-sparing fracture with conductive hearing loss

• The patient likely has an otic capsule disrupting fracture, given the mechanism and immediate facial nerve palsy.
• Commonly they pass through the jugular foramen, internal auditory canal, and foramen lacerum.
• Cerebrospinal fluid (CSF) can leak (4-8 times as likely), and the patient can consequently have meningitis.
• Sensorineural hearing loss (7-25 times as likely) can also occur.

Question 51

A 68-year-old woman is brought to the emergency department by an ambulance after a motor vehicle collision. She is unconscious, and a neurological examination is not possible. Her past medical history is significant for hypertension, coronary artery disease, atrial fibrillation on warfarin, and congestive heart failure. CT scan confirms the presence of a subdural hematoma. Which of the following is the next best step in the management of this patient?

Answer 51

1. Prothrombin complex concentrate
2. Levetiracetam
3. Mannitol
4. Intravenous fluids

• Warfarin greatly worsens the bleeding associated with a head injury.
• One of the first priorities is to reverse the effects of the patient’s anticoagulation rapidly.
• The best medication to immediately start to reverse the warfarin is prothrombin complex concentrate.
• Fresh frozen plasma can also be given, but prothrombin complex concentrate is preferred.

Question 52

A 52-year-old man presents with a large, chronic scalp wound. The wound is located at the site of a previous craniotomy incision, which appears to have dehisced following external beam radiation therapy for a brain tumor. The wound is debrided, and the surgeon is considering closure with a rotation advancement flap. The undermining of this flap takes place in what plane?

Answer 52

1. Between the dermis and the subdermal fat
2. Between the subdermal fat and the galea aponeurotica
   3. Between the galea aponeurotica and the periosteum
3. Between the periosteum and the calvarium

• Local flaps in the face are typically elevated in the subdermal plane, with the exception of the scalp and nasal flaps. Scalp flaps are typically elevated in the subgaleal plane, and nasal flaps are often raised in the submuscular plane.
• The scalp does not stretch as much as the skin of other body regions; therefore, longer back-cuts and larger flaps are often required to close comparatively small defects in this area.
• Incisions in the galea aponeurotica, known as galeotomies, are often employed to permit greater degrees of tissue advancement in the scalp.
• The length of the back cut for a rotation flap will often be four to eight times the diameter of the defect. Rotating tissue beyond 90 degrees is advisable because this will minimize the standing cutaneous deformity that occurs, even though rotating beyond 90 degrees will not result in additional decreases in wound closure tension.

Question 53

A 7-year-old girl is found at the bottom of a swimming pool. Initially, she was in full arrest, but after 5 minutes, she showed sinus tachycardia but no respiratory effort. Intubation was done in the field, and a cervical collar was placed. After transport to the emergency department, she was unresponsive with a blood pressure of 100/60 mmHg, pulse 105 bpm, temperature 34.3 degrees Celsius, and oxygen saturation 100 percent. The pupils were 3 mm and sluggishly responsive to light. There is no response to pain. The lungs show wheezing on the left, and coarse breath sounds bilaterally. The monitor shows sinus tachycardia. There is no rectal tone. Which of the following should be the next step in management?

Answer 53

1. Cervical spine films and CT of the head
2. Portable chest radiograph
3. Arterial blood gas
4. Cerebral angiogram

• Airway, breathing, and circulation have been established.
• The diving accident followed by prolonged submersion often involves cervical spine injuries.
• ECG should be done as there may be prolonged QT but should wait until the patient is no longer hypothermic.
• Other injuries should be diligently sought.

Question 54

A 35-year-old underwent hemispherectomy procedure for the control of his refractory seizures. The patient has been seizure-free for the last six months following the procedure. However, the patient has now been experiencing abnormal movements of his right hand, which occur against his own will. He now has to suffer embarrassing movements during a social gathering because of the same. Sometimes his right hand seems to prevent any tasks which he opts to perform from his left hand. What is the main factor accounting for the occurrence of such clinical behavior seen in the patient following the epilepsy surgery?

Answer 54

1. Superficial hemosiderosis
2. Seizure recurrence
3. Suprasylvian block
   4. Corpus callosotomy

• The patient is exhibiting typical clinical features of an alien hand syndrome following the epilepsy surgery.
• The alien hand syndrome is a variant of a disconnection syndrome seen in some cohort of patients undergoing epilepsy procedures.
• The main factor predisposing to such complications in the patient is the corpus callosotomy, one of the components of the disconnection procedures during the epilepsy surgery.
• The superficial hemosiderosis predisposes to hydrocephalus in the patient. The suprasylvian block may risk the occurrence of hemiparesis the patient owing to the damage to the corticospinal tract.

Question 55

A 17-year-old patient presented to an emergency department following a sudden onset of severe headache. CT head revealed the presence of an acute subarachnoid hemorrhage within the interhemispheric cisterns with evolving hydrocephalus. The treating physician placed an external ventricular drain for managing acute hydrocephalus. However, ten minutes later, the patient deteriorated, and both his pupils were fixed and dilated. What is the most likely cause of this sudden deterioration in the patient?

Answer 55

1. Blockage of the external ventricular drain
   2. Rebleeding
2. Vasospasm
3. Pneumocephalus

• The major cause of mortality in patients with ruptured aneurysmal bleed is rebleeding of the aneurysm.
• The mortality in cases of re-rupture of an aneurysm is as high as 90%.
• The placement of external ventricular drain and egress of cerebral spinal fluid can reduce the tamponade effect from the hematoma onto the aneurysmal dome. This can paradoxically lead to the re-rupture of the aneurysm.
• Vasospasm leads to new clinical deficits but seldom leads to acute malignant intracranial hypertension. The onset of pneumocephalus in cases of acute hydrocephalus is minimal.

Question 56

A 36-year-old man is a restrained driver in a highway speed MVC. He arrives at the trauma bay alert and oriented, but complaining of chest pain. He is found to have a traumatic aortic dissection extending from the distal aortic arch to the hiatus. Which of the following will best prevent postoperative morbidity following repair of the injury?

Answer 56

1. Right tube thoracostomy
2. Lumbar puncture
   3. Spinal drain placement
3. Simultaneous carotid-subclavian bypass

• The longer the stent-graft placed, the higher the risk of spinal ischemia. This is because the increased length of the stent covers more branches from the aorta to the anterior spinal cord.
• Spinal drain placement allows real-time decompression and management of spinal edema if spinal ischemia occurs postoperatively.
• If neurologically changes occur, such as decreased sensation or motor control of the lower extremities, the spinal drain will be opened, allowing for CSF removal and decompression of the edematous spinal cord. A right thoracostomy would not be useful in this scenario. Lumbar puncture is unlikely to provide a significant decrease in spinal pressure.
• A left pleural effusion caused by free hemorrhage may be seen with aortic transection.

Question 57

A 32-year-old female presents with severe low back pain radiating to the right lower limb of one-day duration, which started after lifting a bucket of water. On clinical examination, the straight leg raising test is positive at 40 degrees on the right side. Her right ankle jerk is absent. A magnetic resonance imaging (MRI) scan of the lumbar spine shows a right posterolateral L5-S1 disc prolapse. She undergoes a micro-lumbar discectomy for the same and becomes cured of pain after the surgery. One year later, she again started having the same type of pain. The treating clinician wants to differentiate recurrent disc from that of the postoperative scar in the patient. Which of the following is the most rational imaging modality for the evaluation of the same?

Answer 57

1. Myelography
2. CT discography
   3. Contrast MRI spine
3. CT spine

• Contrast MRI reportedly has 100 percent sensitivity, specificity, and accuracy in differentiating recurrent disc from that of the postoperative scar.
• Scar enhances almost immediately after injection, due to the vascularity of this scar. The recurrent disc shows a slow enhancement over the first 45 minutes of contrast administration and is characteristically always less than that of the adjacent scar.
• Plain MRI was shown to have 100% sensitivity but only 71% specificity, and 89% accuracy in differentiating the same.
• CT discography is an invasive procedure. Myelography is neither sensitive nor specific in the evaluation of the same.

Question 58

A 26-year-old female presents to the clinic with blurry vision for the past month. She also complains of intermittent mild to moderate frontal headaches over the past three months. On examination, she has difficulty abducting the left eye and has papilledema. Visual field charting shows bitemporal hemianopia. On detailed questioning, she reveals that she has had milk discharge from both nipples and amenorrhea over the past six months. Her serum prolactin level is 89 ng/ml. Brain imaging revealed a solid and cystic sellar mass measuring 3 cm with calcification. She subsequently undergoes trans-sphenoidal surgery. The pathology showed dense nodules and trabeculae of squamous epithelium bordered by a palisade of columnar epithelium and yellow-brown cholesterol-rich fluid. What is the most likely diagnosis?

Answer 58

1. Papillary craniopharyngioma
   2. Adamantinomatous craniopharyngioma
2. Pituitary adenoma
3. Prolactinoma

• There are two histologic subtypes of craniopharyngiomas: adamantinomatous and papillary.
• Adamantinomatous craniopharyngioma is primarily seen in pediatric cases but can be seen in adults as well. They have solid and cystic parts. The solid part is characterized by dense nodules and trabeculae of squamous epithelium bordered by a palisade of columnar epithelium, sometimes referred to as a “picket fence.” The cystic part has a yellow-brown, cholesterol- rich fluid.
• Papillary craniopharyngioma is commonly seen in adults. They are mostly solid without calcification. They are characterized as well-differentiated squamous epithelium lacking surface maturation, with occasional goblet cells and ciliated epithelium
• Mild hyperprolactinemia is due to the large size of the sellar mass resulting in the “stalk effect.”

Question 59

A 65-year-old male patient undergoes a transforaminal epidural steroid injection (TFESI) using the Kambin approach at the left L3-4 level. The needle is advanced coaxially with 15 degrees of oblique view. Injection of contrast in the anteroposterior view shows pooling medial to the pedicles without epidural flow. Three weeks later, the patient develops severe incapacitating back pain. What laboratory value is the most important to be checked to confirm the suspected complication that developed in this patient?

Answer 59

1. Hematocrit
   2. ESR
2. Alkaline phosphatase
3. White cell count

• The Kambin approach approaches the epidural space inferior to the exiting spinal nerve. The intervertebral disc anteriorly bounds it, and thus advancing the needle too far forward can result in penetration of the disc.
• An elevated ESR and CRP is the most sensitive laboratory value to diagnose discitis. WBC may or may not be elevated so it is not the best answer.
• Injection of contrast and a safety view in the anterior-posterior plane would show the location of the needle tip in the disc. The severe back pain is an indication that the disc likely has developed a discitis infection.
• Major procedure-related complications and drug-related systemic effects of ESI requiring hospitalization including spine infection, hematoma, and sepsis are very rare. Though the incidence of permanent neurological complications from epidural steroid injections is rare, great care is taken to avoid critical vascular and neurological structures in the vicinity of the needle during injection.

Question 60

A 74-year-old obese man with a 33 pack-year smoking history, hypertension, and alcohol use disorder has a positive sagittal axis of +9 cm and a kyphotic spinal deformity that is causing severe chronic back pain. He is planned to undergo a pedicle subtraction osteotomy to correct his deformity. Which of the following risk factor is most predictive of a major complication following surgery?

Answer 60

1. Age greater than 60 years
2. Hypertension
3. Obesity
4. Smoking

• Patients aged greater than 60 years is the most significant risk factor for a major perioperative complication during adult spinal deformity correction, while obesity is the most predictive of a poorer patient-reported outcome after correction of adult spinal deformity.
• Back pain is the most common complaint associated with adult spinal deformity.
• Adult spinal deformity can cause sagittal or coronal imbalances that can result in postural deficits and decreased function.
• A history of tobacco use and obesity has not been found to have an association with the development of major complications.

Question 61

An 18-year-old man presents after a sudden syncope. He has no past medical history but mentions that he has not been able to see anything in the periphery of his vision for the past four years. All his vital signs are within normal limits. On examination, he has droopy eyelids. An electrocardiogram shows a first-degree heart block. Which of the following findings would confirm this patient’s most likely diagnosis?

Answer 61

1. Ragged red fibers on muscle biopsy
2. Loss of B waves on electroretinography
3. Thinning of the inner retina on macular ocular coherence tomography (OCT)
4. Diffuse white matter hyperintensities on brain MRI

• The patient has Kearns Sayre syndrome (KSS).
• Muscle biopsy is the diagnostic test of this pathology and shows ragged red fibers, similar to other mitochondrial myopathies.
• The main abnormality of macular OCT will be the loss of retinal pigmental epithelium. The inner retinal thickness will be preserved.
• While abnormalities of the brain white matter are frequently seen in patients with KSS, this is a non-specific finding and can not be used to confirm the diagnosis. Patients with KSS do have diffuse retinopathy on electroretinograms, but this is not a confirmatory diagnostic test.

Question 62

A 34-year-old woman was involved in a high- speed motor vehicle collision and was admitted 3 days ago with a right-sided subdural hematoma. She was initially taken to theatre for the evacuation of the clot and was then admitted to intensive care for neuroprotective measures. A delayed scan the following day shows infarction of the lower right occipital lobes. What mechanism explains this distribution of infarct?

Answer 62

1. Basilar artery thrombus due to a hypercoagulable state following trauma
2. Contusion from deceleration injury
3. Compression of the superior cerebellar artery due to transtentorial herniation
   4. Compression of the posterior cerebral artery due to transtentorial herniation

• This infarct is within the distribution of the posterior cerebral artery.
• Transtentorial herniation can cause compression of the posterior cerebral artery against the tentorium cerebelli.
• This causes ischemia in the inferior parietal and occipital region. When bilateral, this can cause cortical blindness. If unilateral, it may present with hemianopia.
• The superior cerebellar artery supplies the cerebellum, and a thrombus in the basilar would cause ischemia within the posterior fossa.

Question 63

A 16-year-old girl presents to the clinic with a scalp swelling on the left occipital region. It has been slowly progressive over the last few years. The examination of the lesion is suggestive of a large osteoma. The CT head confirms the examination finding, and excision of the lesion is planned. The patient is given general anesthesia and is operated on in the lateral position. The lesion is excised, and the bony defect is covered by the titanium mesh cranioplasty. Postoperatively, the patient has weakness of her right elbow and wrist extensors. She is suspected of having axonal damage to the radial nerve following its compression during the surgical positioning. Which of the following modalities is the next best step in the evaluation of this patient?

Answer 63

1. High-resolution ultrasound
2. Electromyography
3. Nerve conduction velocity
   4. Tractography

• The fractional anisotropy and the apparent diffusion coefficient MR sequences have now enabled us for from studying the tractography pattern of the nerve. They are now an integral armamentarium for assessing peripheral nerve injuries.
• The fractional anisotropy in particular studies the axonal density and the pattern of Brownian diffusion of water along the nerve fibers. It, therefore, allows the earliest anatomic assessment of the integrity of the nerve.
• It allows for the visual inspection of any abrupt cut off of the fiber tracts, or comparative analysis regarding any wasting of the fascicles in comparison to that of the healthy counterpart.
• The changes in the electrophysiological studies are only appreciable after the Wallerian degeneration is completed. The wasting in terms of the cross-sectional area of the fascicles from the ultrasound is also possible after a few weeks of injury.

Question 64

A 16-year-old patient with malignant cerebral edema following severe head injury is being paralyzed and managed in ventilatory support. The patient has severe eyelid edema, preventing assessment of his pupillary size. His CT brain shows complete obliteration of all basal cisterns and lateral ventricles. Which of the following is the most rational modality for serial assessment of any neurological deterioration in this patient?

Answer 64

1. Ventricular catheter-guided ICP monitoring
2. Serial MRI brain scan
3. Serial CT brain scan
   4. Optic nerve sheath diameter assessment by ocular ultrasound

• The increase in intracranial pressure dissipates CSF into the distensible walls of the optic nerve, thereby leading to an increment in optic nerve sheath diameter.
• The sequential assessment of the optic nerve sheath diameter (ONSD) by ocular ultrasound is a reliable and economical bedside modality for assessing changes in intracranial pressure.
• The sequential assessment of ONSD has diagnostic as well as prognostic implications in managing patients with severe head injuries.
• Repeat CT and MRI scans impose significant risks and hazards during the repeated transfer of unstable patients to the radiology department. Though external ventricular drain placement is the gold standard in monitoring intracranial pressure, it has a significant risk of infections and displacement. Moreover, it is very difficult to tap the ventricle in this patient, with a high risk of failure.

Question 65

A 32-year-old woman is being evaluated for a number of neurological symptoms. She has no known history of medical conditions, and her family history is unremarkable, as well. Detailed evaluation reveals degeneration of cells in the anterior gray horn of the spinal cord. Which of the following symptoms did the patient most likely present?

Answer 65

1. Lower limb paresthesias
   2. Muscle stiffness
2. Diplopia
3. Cape-like bilateral loss of pain and temperature sensation

• The clinical vignette describes an anterior gray horn disease, likely amyotrophic lateral sclerosis.
• The anterior gray column of the spinal cord contains cell bodies of motor neurons. Hence, muscle stiffness is often the first presenting complaint of diseases of the anterior gray horn.
• Diseases of the anterior gray horn of the spinal cord include amyotrophic lateral sclerosis, spinal and bulbar muscular atrophy, Charcot–Marie–Tooth disease, progressive muscular atrophy, all spinal muscular atrophies, and poliomyelitis.
• Anterior gray horn diseases do not affect sensory or cranial nerve function.

Question 66

A 34-year-old male patient is brought to the emergency department after having been thrown off his bike. He was unconscious at the scene and required immediate intubation. His pulse rate is 64/minute and blood pressure is 160/110 mm Hg. His left-sided pupil is dilated in comparison to the right. An urgent computed tomogram scan of the brain is done which shows an acute extradural hemorrhage involving the left frontotemporal region. It is decided to take him to the operating room. Which of the following anesthetics should not be used in this patient?

Answer 66

1. Succinylcholine
   2. Ketamine
2. Nitrous oxide
3. Enflurane

• Ketamine causes a dissociative state and amnesia.
• The drug also can increase heart rate and blood pressure.
• The increased blood flow due to high blood pressure means that the drug should not be used in patients with intracranial pressure elevation.
• Ketamine does not depress respiration and is an effective analgesic agent.

Question 67

A 54-year-old woman presents to the clinic with a complaint of low back pain for the last 4 months. She has taken anti- inflammatory medications and performed physical therapy. Physical examination shows normal strength testing and negative straight leg raise test, normal Achilles and patellar reflexes bilaterally, no clonus, and a downgoing Babinski sign. Discogenic pain is suspected. Which of the following conditions, if present, is the most appropriate indication for intradiscal electrothermal therapy (IDET) in this patient?

Answer 67

1. A disc bulge at L4-5 with 55% collapse
   2. A disc protrusion less than 3–4 mm
2. Nucleus pulposus herniation
3. Endplate deformation

• IDET is indicated for disc-related chronic low back pain for a select subgroup of patients with non-radicular chronic low back pain who fail to respond to conservative treatment; ideally for annular tears or disc protrusions less than 3–4 mm.
• The goal of thermal disc treatment is to damage the nerve fibers, shrink collagen, and stiffen the disc tissue. This might seal any small tears of the annulus fibrosus.
• IDET is indicated for small disc bulges and well-hydrated disc (less than 50% height loss of intervertebral disc space).
• Large protrusions may precede a nucleus pulposus herniation and neural root compression. This is unlikely to improve with IDET.

Question 68

A 65-year-old man, suffering from uncontrolled type 2 diabetes and hyperlipidemia, presents to the hospital reporting intermittent burning sensation and sensitivity to cold on the right side of his body. His past medical history revealed a lacunar stroke of his thalamus two years ago. The pain has a significant impact on the patient’s quality of life. He has also failed cognitive behavioral therapy and a trial of amitriptyline for his pain. On exam, the patient’s pinprick and temperature sensation are impaired on the right, while proprioception and vibration sensations are intact. Muscle strength is intact bilaterally. Pain coordinates with the area of sensory loss. What is the next best step in the pharmacological management of this patient?

Answer 68

1. Methylcobalamine
   2. Lamotrigine
2. Pregabalin
3. Duloxetine

• Evidence suggests lamotrigine is the most effective anticonvulsant in the treatment of central post-stroke pain such as in thalamic pain syndrome.
• Lamotrigine is second-line after the use of tricyclic antidepressants (TCAs) in the thalamic pain syndrome.
• Lamotrigine reduces neuron hyper-excitability in the case of centralized pain seen in thalamic stroke pain.
• One randomized controlled trial, comparing lamotrigine to amitriptyline, found lamotrigine moderately useful in the treatment of post-stroke pain. Pain relief was seen in 44% of patients.

Question 69

A 1-year-old girl is brought to the clinic with abnormal flattening of the left posterior part of the head. There is no positional preference while sleeping. There is no family history of similar disease. The developmental milestones are normal for her age. A 3D CT (computerized tomography) scan is advised. Which of the following findings is most likely to be seen on this patient’s CT?

Answer 69

1. Synostosis of the left coronal suture
2. Synostosis of sagittal suture
   3. Synostosis of the left lambdoid suture
3. Normal brain anatomy

• The clinical diagnosis is more in favor of synostotic posterior plagiocephaly.
• Synostotic posterior plagiocephaly is due to the synostosis of the lambdoid suture.
• Nonsyndromic craniosynostosis is commonly sporadic.
• In deformational plagiocephaly, a CT scan can be normal.

Question 70

A 45-year-old man suffers an injury during surgery to the basal ganglia structure located dorsally to the substantia nigra, ventrally to the thalamus, and medially to the internal capsule. Which postoperative complication is most likely to develop?

Answer 70

1. Tardive dyskinesia
2. Athetosis
   3. Hemiballismus
3. Parkinsonianism

• Hemiballismus is characterized by involuntary, violent, wide amplitude flinging of the extremities.
• Damage to the subthalamic nucleus is a cause of hemiballismus.
• Hemiballismus is a rare condition and can occur after stroke or trauma and in patients with amyotrophic lateral sclerosis (ALS).
• The subthalamic nucleus is located dorsally to the substantia nigra, ventrally to the thalamus, and medial to the internal capsule.

Question 71

A 32-year-old male presents with right foot pain. The pain started 6 months ago when he tripped with his right foot and fell. His symptoms have been gradually worsening. The pain is described as severe, throbbing, burning, and stabbing. Any physical activity involving the foot worsens his pain and he reports severe sensitivity to even light touch. He denies any associated low back pain or bladder-bowel incontinence. He has a past medical history of peptic ulcer disease. On presentation, his blood pressure was 118/78 and his heart rate was 60. Physical examination showed full strength in all four extremities, intact light touch but severe allodynia, and hyperalgesia to light touch over the right foot. The straight leg raise test was negative. Some purplish foot discoloration, swelling, and brittle fingernails were noted. He underwent an MRI of the lumbar spine which did not show any disc herniations and an EMG/NCS didn’t show any evidence of radiculopathy or peripheral neuropathy. He was also evaluated by orthopedics and underwent an MRI of the foot and ankle as well but it did not reveal any structural abnormality such as fracture or ligament tear. He is currently working with a physical therapist with a focus on graded motor imagery and mirror therapy as manual therapy seems to worsen his pain. He completed cognitive behavioral therapy for pain. The trial of gabapentin, pregabalin, duloxetine, and tramadol was not beneficial. He underwent a right lumbar sympathetic block which provided him 100% pain relief for a day followed by the return of pain. Pain impairs his sleep, function, and quality of life. What would be the best next step in treatment?

Answer 71

1. Spinal cord stimulation
2. Lumbar epidural steroid injection
   3. Dorsal root ganglion stimulation
3. Lumbar discectomy

• The patient’s clinical presentation meets the Budapest criteria for CRPS.
• A negative straight leg raise test and no disc herniation on the MRI-lumbar spine make lumbar radiculopathy less likely. Moreover, EMG/NCS did not show any evidence of lumbar radiculopathy. Therefore a lumbar epidural steroid injection, as well as discectomy, would not be indicated.
• He has trialed conservative treatments including oral neuropathic medications, physical therapy including graded motor imagery and mirror therapy as well as cognitive behavior therapy. The lumbar sympathetic nerve block was diagnostic but didn’t provide any sustained pain relief. Therefore the next step in management would be the consideration of neuromodulation.
• Both spinal cord stimulation and dorsal root ganglion stimulation are effective for the management of complex regional pain syndrome. But the ACCURATE multicenter study in 2017 found that for complex regional pain syndrome, dorsal root ganglion stimulation was more effective than spinal cord stimulation.

Question 72

A 17-year-old male, who suffered from an atlas fracture (C1) and was placed into a halo vest immobilizer (HVI) 1 week ago in traction, presents to the spine clinic for follow-up. The patient denies drainage from all pin sites and reports that he has been washing each site with hydrogen peroxide daily. The patient does report that over the past couple of days, he has been seeing double of everything; however, he believes it could be pain-related. On physical exam, the patient is found to have a loss of lateral gaze of the right eye; otherwise, the patient is neuro intact, and pin sites look clean without drainage. Which of the following is the most likely cause of this condition?

Answer 72

1. Nerve injury by traction from the Halo vest immobilizer
2. Nerve injury by anterior pins placed medial to the “safe zone” bilaterally
3. Nerve injury by the right anterior pin placed medial to the “safe zone”
4. Nerve injury by the right anterior pin placed lateral to the “safe zone”

• To answer this question correctly, One must first be able to diagnose this patient’s condition, then understand the mechanism by which the halo vest immobilizer causes injury to the nerve involved. Anytime a patient reports seeing “double,” this refers to diplopia.
• On physical exam, the patient cannot abduct his right eye; this means his lateral rectus muscle is not working or has lost innervation. The abducens nerve innervates the lateral rectus muscle. Injury to the abducens nerve can occur from traction between the cranium and torso through the HVI. More common in pediatric patients (18 years old).
• Treatment includes observation and release of traction, most resolve spontaneously.
• The supratrochlear nerve can be damaged from an anterior pin placed medial to the “safe zone” however, a patient would have paresthesias and sensation loss over the medial forehead/eyelid and nose bridge. The supraorbital nerve can be damaged when an anterior pin is placed medial to the “safe zone” and note lateral to it. Also, patients with a supraorbital nerve injury will not have diplopia and loss of lateral gaze. Therefore, this answer choice is inaccurate.

Question 73

A posterolateral herniation of the intervertebral disk at disk level L4-L5 affects which of the following nerves?

Answer 73

1. Fourth and fifth lumbar nerve 2. Fourth nerve only
   3. Fifth nerve only
2. Fifth and sixth lumbar nerve

• The lumbar nerves are the five spinal nerves emerging from the lumbar vertebrae.
• A posterolateral herniation of the intervertebral disk at L4-L5 level affects the fifth lumbar nerves.
• The majority of disc herniations occur at L4-L5 and the second most common site is C5-C6, C6-C7.
• The patient will have radicular pain down the leg on one side. Straight leg testing may be positive. An MRI can be done to confirm the degree of stenosis and nerve compression.

Question 74

A 30-year-old patient had recurrent seizures secondary to mesial temporal sclerosis. The treating clinician counsels him of the role of epilepsy surgery for the management of the same. The patient is, however, very apprehensive of the risks of undergoing invasive surgical procedures. He has recently read of the role of noninvasive ultrasound therapy in minimizing the frequency of seizures in similar cohorts of patients. What is the main factor limiting the efficacy of such treatment in the management?

Answer 74

1. Beam phase aberration
2. Skullbone heating
   3. Bone insonation
3. Low efficacy in controlling seizures

• Magnetic resonance-guided focused ultrasound therapy is the recent advances in managing epilepsy, which is noninvasive as well as free of any radiation hazards.
• However, the skull bone hinders the acoustic window needed for the proper delivery of the acoustic beam to ablate the target tissues thermally.
• The bone skull, therefore, connotes the need for a higher dose of the ultrasound beam for the therapy (local heating).
• The beam aberration and the local heating is secondary to the high dose of the beam required for the acoustic window secondary to the skull bone.

Question 75

What part of the brain is associated with memory loss in Wernicke-Korsakoff syndrome?

Answer 75

1. Pons
   2. Thalamus
2. Medulla
3. Brain stem

• The thalamus is associated with memory loss in Wernicke- Korsakoff syndrome.
• When a patient presents with confusion and persistent memory and learning deficits, one should suspect the presence of Wernicke-Korsakoff Syndrome. This syndrome usually presents with a clinical triad consisting of altered mental status (i.e., confusion or dementia), nystagmus or ophthalmoplegia, and ataxia. Unfortunately less than one-third of patients present with this clinical triad. To better understand this disorder, one should think of Wernicke encephalopathy and Wernicke-Korsakoff syndrome as two separate syndromes. Wernicke encephalopathy is characterized by an acute confusional state and often reversible clinical features while Wernicke-Korsakoff syndrome has persistent but often irreversible clinical features, including dementia and gait abnormalities.
• The cause of Wernicke-Korsakoff Syndrome is a deficiency of thiamine or vitamin B1. Individuals with poor nutrition for any reason are at risk for this disorder. The most common social factor associated with Wernicke-Korsakoff Syndrome is chronic alcohol abuse which leads to decreased absorption and utilization of thiamine. However, it is important to note that there are nonalcoholic causes of thiamine deficiency which can also produce Wernicke-Korsakoff Syndrome. These include malnutrition, starvation, schizophrenia, anorexia nervosa, prisoners of war, and terminal malignancies. In the past, baby formula which was deficient in thiamine led to Wernicke- Korsakoff syndrome. Wernicke-Korsakoff Syndrome also can develop during the first trimester of pregnancy in women with hyperemesis gravidarum. Other common causes are bariatric surgery and malignancies of the gastrointestinal tract.
• The diagnosis of Wernicke-Korsakoff Syndrome is made by the history and clinical findings that are supplemented with lab studies showing thiamine deficiency. The aim of treatment is to prevent the disorder from getting worse. One should maintain a high level of suspicion for thiamine deficiency to avoid precipitation of severe symptoms of Wernicke-Korsakoff syndrome. Prophylactic thiamine administration is relatively safe and should be started even if the diagnosis has not been confirmed.

Question 76

A 68-year-old man is being evaluated for intractable chronic back pain. He had spinal surgery two years ago to insert an intrathecal catheter for morphine with a tip at D4 for analgesic therapy. Since the start of the treatment, he has developed progressive swelling and pain with activity and at rest. He reports radicular pain, muscle weakness, point tenderness, and loss of sensation. What is the most likely cause of this patient’s presentation?

Answer 76

1. Granuloma of the catheter tip
2. Hematoma
3. Infection
4. Catheter migration

• Catheter granuloma, also called catheter-associated inflammatory mass, is a noninfectious inflammatory process around the tip of the catheter, which is formed a long time after placement.
• While this complication is generally asymptomatic, it can induce a decrease in the therapeutic effect of intrathecal analgesia and symptoms due to spinal cord compression.
• When possible, lumbar access below the medulla is preferred to avoid neural compression.
• Catheter migration can cause a loss of therapeutic activity. An infection manifests as meningitis or meningoencephalitis. Hematoma presents with symptoms similar to granuloma, but the trend is less progressive, and the differential diagnosis requires neuroimaging.

Question 77

A 66-year-old man undergoes awake craniotomy for glioma resection. Postoperative vital signs include heart rate 82/min, blood pressure 164/86 mmHg, oxygen saturation 96%, and central venous pressure (CVP) 2 mmHg. Postoperative investigations are significant for serum sodium 112 mEq/L and 24- hour urine sodium 320 mEq/L (reference range 40-220 mEq/L). Which of the following is the most most likely cause of hyponatremia in this patient?

Answer 77

1. Acute tubular necrosis
2. Primary hyperaldosteronism
   3. Cerebral salt wasting syndrome
3. Syndrome of inappropriate antidiuretic hormone (SIADH)

• Hyponatremia is a frequent electrolyte imbalance seen in patients who had neurological insults like head injury, SAH, or who had intra-cranial surgery. The two most common causes of hyponatremia in these patients are the syndrome of inappropriate antidiuretic hormone (SIADH) and cerebral salt wasting syndrome (CSW).
• SIADH and cerebral salt wasting syndrome can be differentiated based on the volume status of the patient and urine sodium excretion. The normal urine sodium value is around 20 mEq/L. For the 24-hour urine test, the norm ranges from 40 to 220 mEq/L per day.
• Cerebral salt-wasting syndrome is characterized by hyponatremia, volume contraction, and urine sodium concentrations inappropriately high for the given level of serum sodium. SIADH is characterized by inappropriate secretion of ADH, which causes water retention in the body and dilutional hyponatremia in a clinically euvolemic or hypervolemic patient.
• Hyponatremia associated with SIADH is due to renal retention of free water (rather than excess loss of sodium by the kidney). So, the quantity of sodium collected over the 24-hour period and CVP should be relatively normal in SIADH patients, but in CSW, the quantity of sodium excreted over the 24-hour period will be higher, and CVP will be lower than normal.

Question 78

A 23-year-old woman reports visual disturbances, stating that she can no longer see well peripherally on both the right and the left. She thinks this may be the cause of depressive symptoms as she is lethargic due to weight gain, has insomnia, and can’t concentrate. She denies any change in her caloric intake. On physical examination, she points to numerous changes in her skin such as easy bruising, acne problems, and purple-red striae on her trunk. MRI of her brain shows a tumor. What area of the brain is the tumor most likely found?

Answer 78

1. Occipital lobe
   2. Pituitary
2. Caudate nucleus
3. Putamen

• Cushing disease, unlike Cushing syndrome, refers to one specific cause, a pituitary adenoma.
• Due to the overproduction of adrenocorticotropic hormone (ACTH), these tumors cause a variety of endocrine and psychiatric disturbances.
• Diagnostic tests used are salivary and blood serum cortisol, 24- hour urinary free cortisol, dexamethasone suppression test, and bilateral inferior petrosal sinus sampling. Multiple tests should be used.
• First-line treatment is surgical resection of the ACTH-secreting pituitary adenoma. Pituitary radiation or bilateral adrenalectomy may be needed for postoperative persisting hypercortisolemia.

Question 79

A 29-year-old man is brought to the emergency department following a fall from the staircase. He has had three episodes of vomiting and headache since then. On examination, his vital signs are within normal limits, and the Glasgow coma scale score is E3V5M6. A computed tomogram scan of the brain shows an acute subdural hemorrhage of 0.5 cm thickness in the right frontotemporal region with a midline shift of 2 mm. He is admitted to the neurosurgery intensive care unit, and mannitol is being administered. Which of the following parameters is most appropriate to be monitored closely during the administration?

Answer 79

1. Renal function
2. Blood sugar
3. Deep tendon reflexes
   4. Urine output

• Mannitol is a diuretic administered to reduce cerebral edema.
• Closely monitoring a patient’s input and output while on mannitol is essential. Failure for urine output to increase after administration of mannitol should prompt cessation of mannitol and evaluation for possible renal or genitourinary issues.
• When giving mannitol, it is essential to monitor cardiac function as the fluid shifts can precipitate heart failure.
• Additional electrolytes, including sodium, potassium, and osmolality, all require monitoring. The clinician should stop mannitol if significant electrolyte abnormalities develop or the osmolality reaches 320 mOsm or higher.

Question 80

A 1-year-old boy, the firstborn child of a non- consanguineous marriage following a full-term normal delivery, is brought to the outpatient department with swaying while walking and recurrent episodes of vomiting for the past one month. He had started walking from the 10th month of age onwards, but now he has begun developing difficulty even to walk on plain ground. On examination, there is no neurological finding, except for ataxia. He undergoes a magnetic resonance imaging of the brain, which shows an enhancing mass in the cerebellar vermis with fourth ventricular extension and mild hydrocephalus. What is the most likely diagnosis?

Answer 80

1. Brain stem glioma
2. Dysgerminoma
   3. Medulloblastoma
3. Ependymoma

• The patient’s age, imaging results, and anatomical location, as well as the extension to the fourth ventricle, all are more suggestive of medulloblastoma.
• Ependymomas are the second most likely posterior fossa lesions in this age group.
• Medulloblastomas tend to show a more homogeneous enhancement while ependymomas usually appear heterogeneous, due to internal cysts, calcifications, and hemorrhage.
• Treatment for medulloblastomas is initially maximum surgical removal of the lesion, the addition of radiation and chemotherapy aims to increase disease-free survival.

Question 81

A 50-year-old female presents with escalating subacute headache. Her axial CT of the brain is shown. Which of the following findings is most associated with the disease most likely found in this patient?

Answer 81

1. Frontal lobe predominant
2. Mostly cystic
3. Avid enhancement
4. Associated with Von-Hippel Lindau syndrome

• Oligodendrogliomas are well-differentiated, slow-growing but diffusely infiltrating cortical/subcortical tumors most commonly found in the frontal lobe. They are generally low-grade WHO grade II neoplasms with favorable treatment response when compared to other gliomas.
• Patients with oligodendroglioma most often present with non- specific symptoms such as headache. Seizures may also occur.
• Oligodenrogliomas are complex masses which may contain calcification, hemorrhage, cysts, and proteinaceous material. They are often cortically based and demonstrate gyral expansion. Peritumoral edema and hemorrhage are less common, and contrast enhancement is variable but typically mild. MRI offers a better characterization of the tumor margins and infiltration than CT.
• Surgery is the mainstay of treatment, although adjuvant radiation and chemotherapy may be considered in the treatment of oligodendrogliomas. More favorable outcome is correlated with younger age, frontal location, lack of enhancement, complete resection, and radiation therapy after partial resection.

Question 82

A 51-year-old man with a past medical history of hypertension and diabetes mellitus is brought to the hospital with altered mental status. His wife reports that the patient was involved in a scuffle and received a blow to his head. CT imaging of the brain confirms the presence of grade 4 subarachnoid hemorrhage (modified Fischer scale) with mild ventriculomegaly. On physical examination, the patient is stuporous with a GCS score of 6/15. Which of the following is the next best step in the management of this patient?

Answer 82

1. Endovascular clipping
2. HHH therapy
   3. External ventricular drain placement
3. Cerebral angiography

• The first step in the management of a subarachnoid hemorrhage (SAH) is to stabilize the patient and to get an emergent neurosurgical evaluation. Patients presenting with a decreased GCS may require intubation for airway protection. Blood pressure, pulse, respiratory rate, and GCS must frequently be monitored. Pain control and antiemetics are often required for symptom control.
• An external ventricular drain (EVD) may be indicated if the patient has a poor clinical grade on admission (decreased consciousness), acute neurological deterioration, or progressive ventricular enlargement on CT. This EVD may be used to remove CSF or blood that can cause increased intracranial pressure.
• Modified Fischer scale grade 4 SAH denotes “thick, focal, or diffuse SAH with intraventricular hemorrhage.”
• Although 85% of the cases are caused by a ruptured saccular aneurysm, head trauma causes some cases of SAH.

Question 83

A 58-year-old man presents to the clinic for follow up. He is scheduled to undergo radial forearm tissue transfer for a left tongue defect. He desires to achieve some sensation after surgery to his neo-tongue. Which of the following is the accepted technique for achieving sensation with donor radial forearm tissue transfer?

Answer 83

1. Neurorrhaphy and connection to the chorda tympani
   2. Neurorrhaphy and connection to the lingual nerve
2. Neurorrhaphy with a nerve graft and utilizing the hypoglossal nerve for attachment to the medial/lateral antebrachial nerves
3. To achieve possible sensation, the surgeon must raise the flap deep to the sub-dermal plane

• Medial and lateral antebrachial nerves can be harvested with the flap to possibly achieve a sensate skin flap.
• While sensation can be achieved, the taste is unlikely to be achieved even with the harvest of the lateral and medial antebrachial nerves.
• The flap must be elevated in a subdermal plane so as to not violate and sacrifice lateral and medial antebrachial nerves.
• A unique aspect of this tissue transfer is the ability to achieve a sensate skin flap through reliable donor anatomy

Question 84

A 39-year-old laborer is trapped by a heavy object weighing nearly two tons. He has numbness in the right posterolateral thigh and decreased dorsiflexion of his bilateral ankles and great toes. Radiographs and MRI reveal the L4 inferior articular process to be located anterior to the L5 superior articular processes bilaterally. What is the most appropriate management for this patient?

Answer 84

1. Conservative management with physical therapy and a slow return to function
2. Closed manipulation of the lumbar spine with a chiropractor 3. Anterior corpectomy of L4
   4. Posterior decompression with an interbody fusion of L4-L5

• The locked facet joint is a type of facet joint dislocation that results from jumping of the inferior articular process anterior to the superior articular process of the vertebra below and becomes locked in the position.
• Anatomically, lumbar facet joints are arranged in the sagittal plane weak for hyperflexion yet strong for rotation. Hyperflexion with some amount of distraction is the most frequent mechanism of facet dislocation in the lumbar spine.
• In the case of neurological weakness and lumbar facet dislocation, urgent surgical decompression is warranted. After decompression, the spine must be fused at the affected levels.
• The majority of dislocations involving the lumbar spine occur at the thoracolumbar junction, with decreasing frequency at the lower lumbar levels.

Question 85

A 12-year-old girl is brought in by her parents for a second opinion regarding a two-year history of headaches. She has intermittent throbbing headaches with photophobia that last for between a few hours to 4 days. These occur once or twice per month, and she was diagnosed with migraines. For the past year, she has been having a once-a-month episode of loss of vision for one minute, followed by generalized shaking of the extremities, and subsequently, a pounding headache. She was prescribed rizatriptan with no relief. The patient’s mother has a history of migraine headaches. The physical and neurological examinations are unremarkable. Which of the following is the most appropriate next step in the management of this patient?

Answer 85

1. Request for psychological testing as the patient’s symptoms may be psychosomatic
2. Request for cardiac echo and CT angiography of head and neck as hypoperfusion and transient ischemic attacks are a key differential
3. Reassure the patient that she has complicated migraines and increase the dose of rizatriptan
   4. Request for electroencephalogram (EEG) and head MRI to look for a mass lesion or epileptiform focus

• The patient most likely has occipital epilepsy. Gastaut-type is a late-onset form in the teenage years.
• Gastaut-type occipital epilepsy is classically described to have visual changes, tonic, clonic, or tonic-clonic movements consistent with a seizure and subsequent severe headache.
• Occipital sharps may be seen on EEG recordings.
• Medications used for migraines are inappropriate in this case. The patient should be treated for epilepsy.

Question 86

A 35-year-old patient is brought to an emergency department following a sudden onset of altered sensorium and persistent vomiting. CT head revealed right parieto-occipital lobar bleed with dense tentorial lightening. His blood pressure is 170/100 mm Hg, his temperature is normal, and his pulse is 98 bpm. The patient had been managed for right transverse sinus thrombosis one month back. What is the most likely cause of the deterioration in this patient?

Answer 86

1. Sagittal sinus thrombosis
2. Intracranial hypotension
   3. Dural arteriovenous fistula
3. Hypertensive bleed

• Dural arteriovenous malformation (DAVF) can be a late complication following cortical venous sinus thrombosis. The process is initiated by activating the hypoxia-induced proliferation of vascular endothelial growth factors (VEGF).
• DAVF results from neoangiogenesis aimed at forming collaterals to bypass the thrombosed segment, in cases of failed recanalization, following sinus thrombosis.
• DAVF recruits vascular supply from both the dural as well as cortical vessels. Its rupture thereby leads to both lobar as well as tentorial bleeds.
• Sagittal sinus thrombosis leads to bilateral high frontoparietal territory bleed, following high pressure within the draining cortical veins. The intracranial hypotension leads to characteristic sagging of the major sinuses.

Question 87

A 28-year-old woman, who is having type 1 diabetes mellitus, gives birth to a male baby weighing 3 kg by normal vaginal delivery. The child has to be resuscitated as he did not cry immediately after birth. On further evaluation, after the child is stable, he is noted to have a cloverleaf skull with his anterior fontanelle full, maxillary hypoplasia and resultant proptosis, a beak-shaped nose, inferiorly displaced ears and ankylosis of elbow joints. The presence of which of the following clinical features differentiates a type II from type III of the syndrome in this child?

Answer 87

1. Cloverleaf skull
2. Elbow joint ankylosis
3. Maxillary hypoplasia
4. Beak-shaped nose

• The child is having Pfeiffer syndrome (PS).
• The clinical features of PS type II are cloverleaf skull (Kleeblattschadel type craniosynostosis) which is usually associated with hydrocephalus, maxillary hypoplasia with resultant proptosis, a “beak-shaped” nose, inferiorly displaced ears and ankylosis of elbow joints.
• The clinical findings in patients with PS type III are like those present in PS type II, except for the cloverleaf skull deformity.
• Additional features in type III PS include short anterior cranial fossa base, natal teeth, proptosis and various visceral abnormalities (hydronephrosis, pelvic kidneys, and hypoplastic gallbladder).

Question 88

A 53-year-old woman presents to the clinic for evaluation for intradiscal electrothermal therapy (IDET). She has had a long history of low back pain treated with nonsteroidal anti- inflammatory drugs (NSAIDs), epidural steroids, and physical therapy. She has a history of diabetes type 2, renal failure, and previous 20-pack-year smoking. MRI of lumbar spine shows disc degeneration at L4-L5 with 60% disc height loss. Which of the following factors is the strongest contraindication to IDET in this patient?

Answer 88

1. Previous treatment with epidural steroids
2. Diabetes
3. Renal failure
   4. Severe disc height loss

• Lumbar disc degeneration with more than 50% disc height loss is a contraindication for intradiscal electrothermal therapy (IDET).
• Disc degeneration means that nucleus pulposus and annulus fibrosus become rigid. Patients usually experience constant pain due to severe loss of disc height, and this condition is unlikely to improve with intradiscal electrothermal therapy (IDET).
• When disc height is lost, nerve impingement, bone, and joint inflammation, and resultant pain can occur. Therefore IDET may not allow improvement in this situation.
• Disc height loss may contribute to spinal stenosis and spinal instability. IDET is not recommended for patients with this condition.

Question 89

An 11-year-old boy is brought to the emergency department with complaints of nausea and vomiting accompanying severe headache. He had a ventriculoperitoneal shunt placed due to congenital obstructive hydrocephalus 1 year ago. His vital signs are within normal limits. There is no significant finding on neurological examination other than lethargy. His abdominal examination is unremarkable as well. What is the best initial step in the evaluation of this patient?

Answer 89

1. Shunt x-ray series
2. Contrast-enhanced head CT
3. Phase contrast MRI
4. Radionuclide shunt study

• Congenital obstructive hydrocephalus is associated with a high risk for the development of shunt complications, most commonly the shunt obstruction that characteristically presents with headache, nausea, and vomiting, and lethargy.
• Shunt series consisting of radiographs of the shunt components obtained in at least 2 planes is the imaging method of choice in the initial work-up of patients with suspected ventriculoperitoneal shunt obstruction.
• Low-dose non-contrast CT is an imaging option used as an alternative to the shunt series for evaluating shunt function. However, contrast-enhanced CT is not used for this purpose.
• Phase-contrast MRI is an imaging method used for the qualitative and quantitative evaluation of cerebrospinal fluid flow. Still, it is not used in the evaluation of suspected ventriculoperitoneal shunt failure. Radionuclide shunt study is a technique that can be used in the evaluation of the ventriculoperitoneal shunt malfunction, but not as the first-line.

Question 90

A 20-year-old man is brought to the emergency department after a motor vehicle accident. On arrival, he is in severe pain but is responsive and able to follow commands. His Glasgow coma score is 15. Vital signs include blood pressure 130/80 mmHg, pulse 90/minute, respirations 18/minute, and temperature 37.2 C (98.9 F). The initial assessment demonstrates that the patient has an ASIA impairment scale of E. Bilateral C6/C7 facet dislocations are seen on CT scan. With subsequent assessment, the patient now has an ASIA impairment score of C. What is the next best step in management?

Answer 90

1. MRI of the cervical spine, followed by posterior reduction and stabilization
2. Immediate anterior open reduction and surgical stabilization
3. Rigid cervical collar, methylprednisolone, and serial neurological exams
   4. Immediate closed reduction with cervical traction

• The patient presents with a deteriorating neurologic exam in the presence of a bilateral C5-6 facet dislocation, indicating that there is an acute spinal cord injury either from the initial trauma or secondarily from local inflammation or hemorrhage causing compression. Obtaining a baseline physical exam at the time of presentation is imperative; this will be used to determine if the patient’s neurological status is improving or worsening in subsequent exams.
• Because the patient is alert, cooperative, and sober, the next step in management is an emergent closed reduction with cranial traction while the patient is awake. An ASIA Impairment Scale of E is a normal exam. An ASIA Impairment Scale of C shows preserved motor function below the neurological level, but with more than half of key muscles below the neurological level showing weakness but with a muscle grade less than 3. Therefore the exam is worsening.
• Immediate closed reduction is performed in the awake and cooperative patient with a unilateral or bilateral facet dislocation with or without neurological deficits. This is performed by inserting cranial tongs with axial traction by adding weights from 50-100 lbs with a component of cervical flexion and rotation to aid in reduction. Serial neurological exams and plain lateral radiographs after the addition of each weight. If the neurological exam worsens, remove all weight, and emergent MRI must be performed. Always obtain MRI after reduction in order to determine the best approach for surgical stabilization.
• Because of this rapid decline in motor function, you do not want to wait to obtain an MRI as this could lead to worsening of his neurologic status and potentially permanent damage. However, following closed reduction, an MRI should be obtained to evaluate for a disc herniation, as this will determine the surgical approach for decompression and stabilization. Monitoring with the administration of steroids is improper as the patient’s decline is likely from the compression/injury of the spinal cord and must be reduced in order to decompress the spine. Also, steroids have not shown many benefits in outcomes, and large doses have been associated with significant postoperative complications.

Question 91

A 30-year-old woman presents following a road traffic accident in which she was thrown from a motorbike without a helmet. She has severe neck pain, restriction of neck movements, and quadriparesis. On a cervical x-ray, the sum of lateral masses of C1 over C2 is 10mm. What is the most appropriate management strategy for this patient?

Answer 91

1. Surgery with C1-C2 or occipito-cervical fixation
2. Cervical collar only
3. Physiotherapy only
4. Reassurance

• According to the rule of Spence, the total overhang of C1 lateral masses over C2 should not be more than 7mm. If they are more than 7mm, this indicates an unstable C1 fracture.
• A fusion procedure is the best available option for unstable C1 fractures.
• Fusion can be performed by either an anterior or posterior approach.
• Either C1-C2 fixation or occipito-cervical fusion can be performed depending on the patient’s anatomy.

Question 92

A 17-year-old male with a history of traumatic brain injury and secondary development of partial complex seizures comes to the clinic for a follow-up appointment. He has failed maximal antiepileptic medical therapy. The physician is now considering surgical management for curative treatment. Video electroencephalogram (EEG) demonstrates epileptiform discharges in the left temporoparietal region, which corresponds to encephalomalacia near the left angular gyrus on non-contrast magnetic resonance imaging (MRI). Prior to surgical intervention, what is the next most appropriate step in the management of this patient?

Answer 92

1. Contrast-enhanced brain MRI and magnetic resonance angiography
2. Computed tomography (CT) of the head with or without intravenous contrast
   3. Functional magnetic resonance imaging (MRI) of the brain with blood oxygenation level development (BOLD) imaging
3. Ictal and postictal perfusion single-photon emission computed tomography (SPECT) imaging

• Patients with post-traumatic epilepsy often will have demonstrable abnormalities on MRI, such as encephalomalacia and gliosis. Corresponding lesions with EEG abnormalities are diagnostic of an epileptogenic focus.
• Patients with lesions adjacent to regions of the eloquent neocortex require functional imaging to determine the laterality and location of the language centers within the brain. This allows the surgeon to try and spare as much of these regions as possible if cortical resection is required.
• Contrast administration is only useful if there are suspected vascular lesions or abnormalities associated with the destruction of the blood-brain barrier. In patients with clearly demonstrable abnormalities following traumatic brain injury, contrast administration adds little to their diagnostic workup.
• Single-photon emission computed tomography (SPECT) imaging can help improve the localization of a seizure focus within the brain but is only used as a supplementary imaging modality. It is used in combination with structural imaging from either CT or MRI.

Question 93

An immunocompromised patient who recently had sinusitis presents with seizures. Head CT reveals a frontal abscess. Which of the following would be an unexpected etiology of the patient’s condition?

Answer 93

1. Viridans streptococci
2. Peptostreptococcus
3. Staphylococcus aureus
   4. Pseudomonas aeruginosa

• Etiologic causes of brain abscess are often polymicrobial.
• Gram-positive bacteria and anaerobes are common causes.
• Gram-negative bacteria such as Pseudomonas aeruginosa are seldom implicated.
• Brain abscess is a focal area of necrosis with a surrounding membrane within the brain parenchyma, usually resulting from an infectious process or rarely from a traumatic process. A brain abscess can originate from infections in the head and neck, lung, heart, skin, pelvis, and abdomen. Facial trauma, even from neurosurgical procedures, can result in necrotic tissue, and brain abscesses have been reported afterward. Metal fragments or other foreign bodies left in the brain parenchyma can also serve as a nidus for infection. The most frequent microbial pathogens isolated from a brain abscess are Staphylococcus and Streptococcus. Among this class of bacteria, Staphylococcus aureus and Viridian streptococci are the commonest.

Question 94

A 65-year-old woman with a medical history significant for multiple cardiovascular accidents presents to the office for persistent, paroxysmal facial pain, as well as sensitivity to cold and heat. Her symptoms began one year ago. The patient’s pain is mildly controlled with a fentanyl patch. She has failed multiple medications for her symptoms, including amitriptyline, gabapentin, and sertraline. She has never had any procedures or surgeries done for her pain. On exam, her pinprick and temperature sensation is impaired, while their proprioception and vibration sensation is intact. Her cranial nerves are intact bilaterally. The patient is concerned her facial pain is getting worse and would like immediate pain relief if possible. What can be done to help this patient?

Answer 94

1. Transcutaneous electrical nerve stimulation (TENS)
   2. Motor cortex stimulation
2. Deep brain stimulation
3. Carbamazepine trial

• Motor cortex stimulation can be used to help treat facial pain associated with central post-stroke pain (thalamic pain syndrome).
• Motor cortex stimulation is effective in two-thirds of patients with central post-stroke pain.
• Of patients who had relief with motor cortex stimulation, at least 40% of pain relief was achieved.
• Motor cortex stimulation is an effective treatment method for both thalamic pain syndrome and central post-stroke pain syndromes outside of the thalamus.

Question 95

A 7-year-old male child is brought to the emergency department following an 18-foot fall from a balcony onto cement with a brief loss of consciousness. The initial CT on admission is notable for a small left frontal contusion with minimal edema. Approximately 6 hours following admission, the child has a seizure. An urgent CT scan is done, which documents a subarachnoid hemorrhage in the left Sylvian fissure. What would be the next appropriate consideration in the management of this patient?

Answer 95

1. Assess the patient for a penetrating head injury likely to be missed previously following the injury
   2. Initiate anticonvulsant therapy
2. Obtain 4 vessels cerebral angiography to assist in identifying the origin of the bleed
3. Obtain MRI with contrast to further evaluate the left frontal contusion

• Traumatic aneurysms may result from either penetrating head trauma or closed head trauma. Aneurysms following penetrating injury occur most often in teenage boys following a cranial cerebral gunshot wound. Aneurysms resulting from closed head trauma can occur either from injuries to the skull base or convexity. Injuries involving the skull base frequently can cause aneurysms originating from the petrous, cavernous, or supraclinoid carotid arteries. As with aneurysms resulting from penetrating trauma, these are more likely to occur in teenage boys. Injuries to the convexity can involve the distal component of the anterior cerebral artery because of the falcine edge. Distal cortical aneurysms are usually associated with an associated skull fracture. A penetrating injury would have been ruled out by the admission exam and CT.
• The initiation of anticonvulsants would be appropriate as it is uncertain at this point whether the seizure results from the contusion or subarachnoid hemorrhage (SAH). An intravenous administration of levetiracetam 20 mg/kg would be one consideration. A postictal exam is requisite to determine if the decline in the child’s Glasgow coma scale requires intracranial pressure monitoring.
• Additional imaging would be appropriate to rule out a potential rupture of a traumatic intracranial aneurysm. Imaging preference regarding MR-angiography versus CT-angiography (CTA) is usually institution-specific. CTA will often provide a better image, though at the expense of additional radiation to the child.
• Four-vessel angiography is the gold standard diagnostically and requisite in not only ruling in a traumatic aneurysm, but also in assisting the surgeon in determining the appropriate surgical, medical, and/or interventional treatment.

Question 96

A 17-year-old man sustained an injury to the face following an explosion at the workplace. He was brought to the emergency department within 2 hours. On examination, his eye- opening could not be assessed due to periorbital ecchymosis. He was confused but obeying commands. His vital signs were pulse rate: 74 beats/minute and blood pressure: 120/80 mm Hg. He had undergone a computed tomogram of the head, which shows pan facial and base of skull fractures with mild pneumocephalus. He had undergone maxillofacial surgeries, and the base of skull fracture was managed conservatively. He presents 4 weeks later to the clinic for evaluation of right-sided proptosis, visual impairment, and limitation of ocular movements. On physical examination, the right eye appears to be pulsating. Which of the following is the most appropriate next step?

Answer 96

1. Beta-2 transferrin assay
2. Carotid duplex
   3. Cerebral angiography
3. Craniotomy

• The patient has features of a carotid-cavernous fistula (CCF) on the right side.
• There is likely to be an abnormal communication between the internal carotid artery and the cavernous sinus.
• This patient needs an angiogram to identify the site and size of abnormal communication.
• CCF can be mistaken for an orbital apex syndrome or even stroke.

Question 97

A 65-year-old man has been diagnosed with failed back surgery syndrome. His pain is not controlled despite maximum doses of oral opioids. The treating clinician then advises him for pain management by the intrathecal drug delivery system (IDDS). The patient shows a good clinical response for the initial 6 months. Then he starts developing severe pain radiating down his left leg. The symptoms keep aggravating to the point that he develops weakness in his bilateral lower limbs. An MRI spine reveals enhancing intradural lesion at the tip of the catheter tip. Which of the following is the next best step in the management of this patient?

Answer 97

1. Surgery
2. Cortincoteroid therapy
   3. Stop the intrathecal opioid therapy and assess for the regression of the lesion
3. Broad-spectrum antibiotics

• The patient most likely has developed intrathecal catheter tip granuloma formation seen as the intradural mass, causing the neurological deterioration in the patient.
• Catheter tip granuloma develops following activation of the protein kinase leading to monocyte migration surrounding the catheter tip at the arachnoid layer. This is visualized as the enhancing intradural lesion at the tip of the catheter.
• The high dose of intrathecal opioid is postulated for the pathogenesis of the formation of catheter tip granuloma. Therefore, the lowest possible dose of opioids needs to be prescribed in the patient. The first step in the management is to stop opioid therapy and assess the spontaneous regression of the lesion.
• Abscess formation leads to high-grade fever with chills and rigors. The surgery in cases of catheter tip granuloma is only indicated in cases of persistent and worsening neurological deficits in the patient or cases with a diagnostic dilemma.

Question 98

A 65-year-old woman presents with her son with complaints of mental and personality changes for the past month. The son has noticed that she has become socially inactive, slow in manual tasks and that she keeps on forgetting things. The patient has occasional headaches but denies any history of head trauma. Her past medical history includes hysterectomy 30 years ago for nonmalignant causes, hypertension, and she is currently on diuretics. The neurological examination is normal. Her mini-mental status examination score is 19/30. Blood tests were unremarkable. What is the most likely finding on the CT scan of the head?

Answer 98

1. Hyperdense bilateral fluid collections in the epidural space
2. Hyperdense bilateral fluid collections in the subdural space
   3. Hypodense bilateral fluid collections in the subdural space
3. Hypodense bilateral fluid collections in the epidural space

• Acute bleeds are hyperdense, but chronic subdural hematomas are hypodense.
• 20% to 30% of patients present without a history of trauma.
• Symptoms include headache, mental status changes, focal signs, and seizures, but some patients are asymptomatic.
• Observation may be reasonable for asymptomatic patients with small hematomas, but surgical evacuation is needed for large or symptomatic chronic hematomas. Hypodense bilateral fluid collections in the subdural space are usually seen in the CT scan.

Question 99

A patient with a history of testicular cancer and hyperlipidemia complains of low back pain for 4 months. Walking makes the pain worse, as does standing too long. Sitting and lying down reduces the pain. He denies radiation of the pain, numbness, or tingling. Exam shows 4/5 strength of the left leg from the hip flexors down. Sensory exam is intact. Deep tendon reflexes are diminished at the left lower extremity. Select the most probable diagnosis.

Answer 99

1. Metastatic malignancy
   2. Lumbar spinal stenosis
2. Lumbar disc herniation
3. Tethered cord

• The patient has neurogenic claudication, or increased pain with walking or standing.
• This is often secondary to spinal stenosis.
• Spinal stenosis can be severe, with paralysis and incontinence, or totally asymptomatic.
• Lumbar disc disease is usually worse with sitting.

Question 100

An 11-year-old boy is brought to the emergency department with a headache and blurred vision for the last four weeks. On physical examination, he has ataxia, nystagmus, and papilloedema. The provider obtains a magnetic resonance image (MRI) of the head, which shows a posterior fossa lesion focused within the midline of the cerebellum. It has a large cystic component and an enhancing nodular mural, which shows a high signal on T2. An urgent frozen section is sent during surgery, which shows low cellularity and cells with long bipolar processes. Which of the following is the first-line management option for this tumor?

Answer 100

1. Surgical resection with chemotherapy
2. Radiotherapy alone
   3. Complete surgical resection with no other treatment modality
3. Surgical tumor debulking with radiotherapy of the tumor bed and chemotherapy

• The patient has a pilocytic astrocytoma. These are curative on complete surgical resection alone.
• Radiotherapy may have a role if some aspects of the tumor are not resectable.
• Pilocytic astrocytoma is classified by the World Health Organization (WHO) as grade I gliomas. They are usually cystic with a mural nodule, although some can be solid with little to no cystic component.
• There is no role for chemotherapy.