skip to main content

PML – Diagnosis on Natalizumab — SCE Neurology MCQ

Instant feedback + full explanation. One question, done properly.

HardMultiple Sclerosis & CNS InflammationPML – Diagnosis on NatalizumabSCE Neurology

A 40-year-old woman with MS on natalizumab develops progressive cognitive decline and subtle left weakness over 2 weeks. MRI shows a large non-enhancing white matter lesion with restricted diffusion. CSF JCV PCR is positive. Diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Progressive multifocal leukoencephalopathy — confirmed by CSF JCV PCR positivity

PML shows large non-enhancing lesions affecting subcortical U-fibres with restricted diffusion — different from enhancing MS lesions. CSF JCV confirms diagnosis. Management: stop natalizumab, PLEX to accelerate clearance, monitor for IRIS. A: Non-enhancing pattern and JCV confirms PML. C: Progressive course. D: Monophasic. E: Different imaging.

Reference: ABN MS Guidelines; McGuigan et al.