Neuromuscular Disorders USMLE Step 1 Practice Question
A 5-month-old male presents with progressive weakness and poor head control over 2 months. Vital signs: HR 110, RR 22, SpO2 98% on room air. Examination reveals severe hypotonia, tongue fasciculations, and absent deep tendon reflexes. Cognition and eye movements remain intact. Serum creatine kinase is markedly elevated at 8,200 U/L. The infant has not received any medications. Which of the following is the most likely diagnosis?
Answer choices
- ASpinal muscular atrophyCorrect answer
- BBotulism
- CDuchenne muscular dystrophy
- DGuillain Barré syndrome
- EMyasthenia gravis
- FNemaline rod myopathy
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