Demyelinating Diseases USMLE Step 1 Practice Question
A 52-year-old man presents with progressive lower extremity weakness, spasticity, and hyperreflexia over 3 months. Vital signs: BP 138/82, HR 88, RR 16, Temp 37.2°C, SpO2 98% on room air. MRI of the cervical and thoracic spine demonstrates longitudinal T2 hyperintensity extending from C2 to T6. Brain MRI is normal. Cerebrospinal fluid analysis reveals mild pleocytosis (12 WBC/μL) without oligoclonal bands. Which diagnosis best explains these findings?
Answer choices
- ASpinal cord compression
- BMultiple sclerosis
- CPrimary progressive MS
- DSubacute combined degeneration from B12 deficiencyCorrect answer
- ENeuromyelitis optica spectrum disorder
- FIntramedullary spinal cord ependymoma with longitudinal T2 expansion
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