Neuromuscular Disorders USMLE Step 1 Practice Question
A 49-year-old man presents with 4 months of progressive symmetric weakness and paresthesias in his arms and legs. Vital signs: BP 138/82, HR 88, RR 16, Temp 37.2°C, SpO2 98%. Deep tendon reflexes are diminished throughout. Nerve conduction studies demonstrate demyelination with conduction slowing. CSF protein is elevated at 78 mg/dL. Unlike acute Guillain-Barré syndrome, his course has been prolonged and relapsing. He denies respiratory symptoms. Which diagnosis best explains these findings?
Answer choices
- ACauda equina syndrome
- BToxic myopathy from statins
- CChronic inflammatory demyelinating polyneuropathyCorrect answer
- DMyasthenia gravis
- EAmyotrophic lateral sclerosis
- FPOEMS syndrome (polyneuropathy from osteosclerotic myeloma)
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