MD Central Nervous System Disorders 4

Question 1

A 35-year-old woman presents with episodic unilateral headache, nausea, photophobia, and phonophobia lasting 4-72 hours. She notes visual aura preceding attacks. What is the classification?

Accepted Answer

Migraine with aura

Answer

Recurrent unilateral headache with nausea, photophobia, and preceding visual aura fulfills criteria for migraine with aura.

Question 2

A patient with longstanding type 2 diabetes presents with distal symmetric burning pain and loss of vibration sense in the feet. Which pathway is primarily damaged?

Accepted Answer

Dorsal columns and small unmyelinated C-fibers

Answer

Diabetic peripheral neuropathy affects both small fibers (pain/temperature, C-fibers) and large fibers (vibration, dorsal column) in a length-dependent pattern.

Question 3

A 65-year-old smoker presents with proximal limb weakness that improves with repeated muscle use. Reflexes are absent but return after exercise. What antibody mediates this condition?

Accepted Answer

Anti-voltage-gated calcium channel (VGCC)

Answer

Lambert-Eaton myasthenic syndrome is caused by anti-VGCC antibodies that reduce presynaptic acetylcholine release, often paraneoplastic with SCLC.

Question 4

A 28-year-old presents with subacute confusion, psychiatric symptoms, orofacial dyskinesias, and CSF showing mild pleocytosis. What is the most likely diagnosis?

Accepted Answer

Anti-NMDA receptor encephalitis

Answer

Anti-NMDA receptor encephalitis classically presents in young women with psychiatric prodrome, dyskinesias, autonomic instability, and CSF pleocytosis.

Question 5

Which of the following is the mechanism of action of memantine in Alzheimer disease?

Accepted Answer

NMDA receptor antagonism

Answer

Memantine is an NMDA receptor antagonist that reduces excitotoxic glutamate signaling, approved for moderate-to-severe Alzheimer disease.

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Practice Test

MD Central Nervous System Disorders 4