OFFERED BY AMERICAN BOARD OF
PSYCHIATRY & NEUROLOGY (ABPN) |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 72-year-old male with hypertension and diabetes
presents with acute onset of right-sided weakness
and aphasia. Last known well was 2 hours ago. CT
head shows no hemorrhage. What is the most
appropriate next step?
A) IV alteplase (tPA)
B) Aspirin 325 mg
C) CT angiography
D) Transfer for thrombectomy
Correct answer: A
Rationale: Acute ischemic stroke within 3 hours (4.5
hours with extended criteria) without hemorrhage: IV
tPA if no contraindications. Do not delay for CTA.
2. A 45-year-old female presents with a 2-week
history of progressive ascending weakness starting
in the feet, now involving the legs and arms. She
areflexic. LP shows elevated protein (120 mg/dL) with
normal WBC. What is the most likely diagnosis?
,A) Guillain-Barré syndrome (GBS)
B) Transverse myelitis
C) Multiple sclerosis
D) Myasthenia gravis
Correct answer: A
Rationale: GBS: ascending weakness, areflexia,
albuminocytologic dissociation (elevated protein,
normal WBC). IVIG or plasmapheresis.
3. A 35-year-old female presents with a 3-day history
of severe headache, fever, and photophobia. Lumbar
puncture shows WBC 500 (90% lymphocytes),
glucose 40 (serum 100), protein 100. What is the most
likely organism?
A) Viral meningitis
B) Bacterial meningitis
C) Tuberculous meningitis
D) Fungal meningitis
Correct answer: A
Rationale: Viral meningitis: lymphocytic
predominance, normal to mildly low glucose,
elevated protein. Bacterial has PMN predominance
and very low glucose.
,4. A 68-year-old male with Parkinson's disease for 8
years presents with worsening mobility and falls. He
is on carbidopa-levodopa 25/100 four times daily.
Exam shows choreiform movements of the trunk and
limbs. What is the most likely diagnosis?
A) Levodopa-induced dyskinesia
B) Parkinson's disease progression
C) Huntington disease
D) Tardive dyskinesia
Correct answer: A
Rationale: Levodopa-induced dyskinesia occurs in
50-80% of Parkinson's patients after 5+ years. Chorea
is characteristic. Reduce levodopa or add
amantadine.
5. A 55-year-old female presents with acute onset of
vertigo, nystagmus, and inability to walk. Dix-Hallpike
testing is negative. She has no hearing loss. What is
the most appropriate next step?
A) MRI brain with diffusion-weighted imaging (DWI)
B) Epley maneuver
C) Meclizine and discharge
D) CT head
, Correct answer: A
Rationale: Central vertigo (negative Dix-Hallpike,
unable to walk, no hearing loss) requires MRI to rule
out posterior circulation stroke. Meclizine is for
peripheral vertigo.
6. A 32-year-old female presents with a 3-month
history of episodic right-sided facial numbness and
weakness that lasts 2 minutes. Exam is normal. What
is the most likely diagnosis?
A) Multiple sclerosis (MS) – trigeminal neuralgia
B) Bell palsy
C) Stroke
D) Migraine with aura
Correct answer: A
Rationale: Trigeminal neuralgia (tic douloureux) is a
common presenting symptom of MS (due to
demyelination of CN V). Paroxysmal, brief.
7. A 28-year-old female presents with acute onset of
painless monocular vision loss over 2 days. She has a
history of optic neuritis 2 years ago. MRI brain shows
periventricular white matter lesions. What is the most
likely diagnosis?