Neurodegenerative Diseases USMLE Step 1 Practice Question
A 29-year-old woman presents with fluctuating ptosis and diplopia worsening toward evening. She reports fatigue when chewing tough foods, with strength improving after brief rest. Vital signs are stable (BP 118/76, HR 72, RR 14, Temp 37°C, SpO2 98%). Serum anti-acetylcholine receptor antibodies are positive. Neuroimaging shows no intracranial masses. She denies recent infections or medication changes. Which of the following is the most likely diagnosis?
Answer choices
- AMyasthenia gravisCorrect answer
- BGuillain-Barre syndrome
- CAmyotrophic lateral sclerosis
- DLambert-Eaton myasthenic syndrome
- EBotulism
- FMyasthenic crisis secondary to thymic lymphoma
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