MCCQE Neurological Disorders 2 — Questions and Answers
Question 1: A 25-year-old woman presents with ascending weakness that began in her feet 2 weeks after a gastrointestinal illness. Deep tendon reflexes are absent bilaterally. CSF shows elevated protein with normal cell count. What is the most likely diagnosis?
- Transverse myelitis
- Botulism
- Guillain-Barré syndrome (Correct answer)
- Multiple sclerosis
Correct answer: Guillain-Barré syndrome
Guillain-Barré syndrome presents with ascending flaccid paralysis, areflexia, and albuminocytologic dissociation (high CSF protein, normal cells) often following infection.
Question 2: A 70-year-old man develops sudden-onset severe headache described as 'the worst headache of my life,' followed by neck stiffness. CT head is normal. What is the next most important diagnostic step?
- MRI brain with contrast
- Lumbar puncture for CSF analysis (Correct answer)
- CT angiography
- EEG
Correct answer: Lumbar puncture for CSF analysis
A negative CT does not exclude subarachnoid hemorrhage; lumbar puncture should be performed to look for xanthochromia and red blood cells in the CSF.
Question 3: A 45-year-old woman with known HIV presents with headache, fever, and confusion over 5 days. CSF India ink preparation shows encapsulated yeast. What is the most appropriate treatment?
- Amphotericin B plus flucytosine (Correct answer)
- Fluconazole monotherapy
- Acyclovir
- Ceftriaxone plus vancomycin
Correct answer: Amphotericin B plus flucytosine
Cryptococcal meningitis (seen on India ink as encapsulated yeast) is treated with induction therapy using amphotericin B plus flucytosine for at least 2 weeks.
Question 4: A 30-year-old man presents with acute-onset severe eye pain, diplopia, and proptosis. MRI reveals a lesion in the cavernous sinus. Which cranial nerve is NOT typically affected by cavernous sinus pathology?
- CN III (oculomotor)
- CN VI (abducens)
- CN VII (facial) (Correct answer)
- CN V1 (ophthalmic division of trigeminal)
Correct answer: CN VII (facial)
The facial nerve (CN VII) does not pass through the cavernous sinus; the structures within it include CN III, IV, V1, V2, and VI, as well as the internal carotid artery.
Question 5: A 65-year-old woman with hypertension presents with sudden-onset right-sided hemiplegia and hemisensory loss. CT shows a hyperdense lesion in the left internal capsule. What type of stroke is most likely?
- Embolic ischemic stroke
- Lacunar infarct
- Hypertensive intracerebral hemorrhage (Correct answer)
- Subdural hematoma
Correct answer: Hypertensive intracerebral hemorrhage
A hyperdense lesion on CT indicates hemorrhage; hypertensive ICH most commonly affects the basal ganglia and internal capsule, causing contralateral hemiplegia.
Question 6: A 50-year-old man has progressive gait disturbance with wide base, urinary incontinence, and cognitive decline over 6 months. CT head shows dilated ventricles disproportionate to sulcal atrophy. Which condition is most likely?
- Alzheimer's disease
- Communicating hydrocephalus (normal pressure hydrocephalus) (Correct answer)
- Subdural hematoma
- Multi-infarct dementia
Correct answer: Communicating hydrocephalus (normal pressure hydrocephalus)
Normal pressure hydrocephalus classically presents with the triad of gait apraxia, urinary incontinence, and dementia, with communicating hydrocephalus on imaging.
Question 7: A 28-year-old woman presents with acute onset of right eye pain and vision loss. Examination reveals a relative afferent pupillary defect and decreased color vision. MRI shows enhancement of the right optic nerve. What is the most likely diagnosis?
- Acute angle-closure glaucoma
- Optic neuritis (Correct answer)
- Central retinal artery occlusion
- Ischemic optic neuropathy
Correct answer: Optic neuritis
Optic neuritis presents with painful vision loss, relative afferent pupillary defect, impaired color vision, and optic nerve enhancement on MRI, often associated with multiple sclerosis.
MCCQE Neurological Disorders 2
A 25-year-old woman presents with ascending weakness that began in her feet 2 weeks after a gastrointestinal illness.
Deep tendon reflexes are absent bilaterally.
CSF shows elevated protein with normal cell count.
What is the most likely diagnosis?