Demyelinating Diseases USMLE Step 1 Practice Question
A 33-year-old woman with relapsing-remitting MS on natalizumab therapy presents with progressive cognitive decline and personality changes over 3 months. Vital signs: BP 118/76, HR 88, RR 16, Temp 37.2°C, SpO2 98%. Brain MRI reveals a new frontal lobe lesion with peripheral edema. CSF analysis shows JC virus DNA; protein is normal. She denies fever or focal neurologic deficits. Which complication has developed?
Answer choices
- ASecondary progressive multiple sclerosis
- BCNS lymphoma from immunosuppression
- CNatalizumab-induced encephalitis
- DMS relapse with cognitive impairment
- EProgressive multifocal leukoencephalopathyCorrect answer
- FToxoplasmosis encephalitis with CD4+ T-cell depletion
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