Demyelinating Diseases USMLE Step 1 Practice Question
A 31-year-old woman with multiple sclerosis on natalizumab for 18 months presents with progressive cognitive decline, right-sided weakness, and visual field defect. Vital signs: BP 128/82, HR 88, RR 16, Temp 37°C, SpO2 98%. Brain MRI reveals multifocal white matter lesions without gadolinium enhancement. CSF JC virus PCR is positive; oligoclonal bands are negative. She denies fever and has no recent infections. Which diagnosis best explains these findings?
Answer choices
- AProgressive multifocal leukoencephalopathyCorrect answer
- BMS disease progression
- CNatalizumab-associated posterior reversible encephalopathy syndrome
- DAcute hemorrhagic encephalitis
- ECNS toxoplasmosis
- FTertiary neurosyphilis with general paresis of the insane
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