Progressive multifocal leukoencephalopathy — SCE Neurology MCQ

Correct answer: A — Natalizumab-associated progressive multifocal leukoencephalopathy, given the imaging pattern, in this presentation

The best answer is “Natalizumab-associated progressive multifocal leukoencephalopathy, given the imaging pattern, in this presentation”. The subacute cortical-network deficit, characteristic non-enhancing white-matter pattern, natalizumab exposure and JC-virus detection establish PML. “A typical multiple-sclerosis relapse with an enhancing inflammatory plaque” remains a plausible alternative in a different presentation, but it does not fit the decisive finding or management threshold here. “Posterior reversible encephalopathy syndrome caused by severe hypertension” remains a plausible alternative in a different presentation, but it does not fit the decisive finding or management threshold here. “Primary CNS lymphoma with an enhancing mass lesion” remains a plausible alternative in a different presentation, but it does not fit the decisive finding or management threshold here. “Acute disseminated encephalomyelitis after a recent infection” remains a plausible alternative in a different presentation, but it does not fit the decisive finding or management threshold here.

Reference: MHRA natalizumab: updated advice to support early PML detection: https://www.gov.uk/drug-safety-update/natalizumab-tysabri-progressive-multifocal-leukoencephalopathy-updated-advice-to-support-early-detection