Neurodegenerative Diseases USMLE Step 1 Practice Question
A 2-year-old boy presents to the emergency department with constipation, weak cry, and progressive descending flaccid paralysis. Vital signs show HR 95/min, RR 18/min, BP 95/60 mmHg, temperature 37°C, and SpO2 98% on room air. Parents report he ingested homemade herbal honey syrup 72 hours ago. Ptosis and dilated pupils are noted on examination. Stool culture grows gram-positive rods. The child denies recent diarrheal illness. Which mechanism best explains his neurologic decline?
Answer choices
- AAutoantibodies against acetylcholine receptors
- BAutoantibodies against voltage-gated calcium channels
- CDemyelination of peripheral nerves
- DDestruction of anterior horn cells by virus
- EInhibition of acetylcholine release at the neuromuscular junctionCorrect answer
- FBlockade of acetylcholine receptors by competitive antagonism
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