ABEM Neurological & Psychiatric Disorders 2 — Questions and Answers
Question 1: A 68-year-old man presents with sudden-onset vertigo, ipsilateral facial numbness, contralateral body numbness, hoarseness, and dysphagia. What is the most likely diagnosis?
- Wallenberg syndrome (lateral medullary syndrome) (Correct answer)
- Central pontine myelinolysis
- Basilar artery occlusion
- Cerebellar hemorrhage
Correct answer: Wallenberg syndrome (lateral medullary syndrome)
Wallenberg syndrome results from posterior inferior cerebellar artery (PICA) occlusion causing lateral medullary infarction with crossed sensory deficits and cranial nerve findings.
Question 2: A patient on lithium presents with coarse tremor, ataxia, and confusion with a lithium level of 2.8 mEq/L. Which intervention is most critical?
- Administer sodium bicarbonate IV
- Begin hemodialysis (Correct answer)
- Give activated charcoal
- Administer thiamine 100 mg IV
Correct answer: Begin hemodialysis
Severe lithium toxicity (level >2.5 mEq/L with neurological symptoms) requires hemodialysis, as lithium is not protein-bound and is dialyzable.
Question 3: A 25-year-old woman presents with ascending weakness starting in the legs over 3 days, areflexia, and mild autonomic instability. CSF shows albuminocytologic dissociation. What is the priority concern?
- Imminent respiratory failure (Correct answer)
- Aspiration pneumonia
- Cardiac arrhythmia
- Urinary retention
Correct answer: Imminent respiratory failure
In Guillain-Barré syndrome, respiratory muscle involvement causing respiratory failure is the most immediately life-threatening complication requiring serial FVC monitoring.
Question 4: A 45-year-old with known alcoholism presents after a seizure. He last drank 48 hours ago. His blood alcohol level is 0. What is the MOST appropriate next step?
- Load with phenytoin IV
- Administer lorazepam and thiamine (Correct answer)
- Order CT head with contrast
- Start propofol infusion
Correct answer: Administer lorazepam and thiamine
Alcohol withdrawal seizures are best treated with benzodiazepines; thiamine must be given prior to or concurrently with glucose to prevent precipitating Wernicke encephalopathy.
Question 5: A 30-year-old presents with acute onset of severe agitation, hyperthermia (40.5°C), diaphoresis, myoclonus, and hyperreflexia after starting a new medication. Which drug combination most likely caused this?
- Tramadol and sertraline (Correct answer)
- Haloperidol and benztropine
- Amitriptyline alone
- Clonazepam and alcohol
Correct answer: Tramadol and sertraline
Serotonin syndrome is caused by excess serotonergic activity, classically from combining opioids with serotonin activity (tramadol) and SSRIs.
Question 6: A 72-year-old nursing home patient presents with gradual cognitive decline, urinary incontinence, and a wide-based magnetic gait. CT shows enlarged ventricles disproportionate to cortical atrophy. What condition should be ruled out?
- Normal pressure hydrocephalus (Correct answer)
- Alzheimer dementia
- Multi-infarct dementia
- Creutzfeldt-Jakob disease
Correct answer: Normal pressure hydrocephalus
Normal pressure hydrocephalus presents with the classic triad of gait apraxia, urinary incontinence, and dementia, and is potentially reversible with VP shunting.
Question 7: A 55-year-old presents with thunderclap headache of maximal intensity at onset. CT head is negative. What is the next most appropriate step?
- Discharge with analgesics and neurology follow-up
- Perform lumbar puncture to evaluate for xanthochromia (Correct answer)
- Start IV dexamethasone
- Order MRI brain without contrast
Correct answer: Perform lumbar puncture to evaluate for xanthochromia
A negative CT does not rule out subarachnoid hemorrhage; lumbar puncture to detect xanthochromia is required when CT is negative in the setting of thunderclap headache.
ABEM Neurological & Psychiatric Disorders 2
A 68-year-old man presents with sudden-onset vertigo, ipsilateral facial numbness, contralateral body numbness, hoarseness, and dysphagia.
What is the most likely diagnosis?