Progressive multifocal leukoencephalopathy is a rare and often fatal viral disease characterized by progressive damage or inflammation of the white matter of the brain at multiple locations. Wikipedia

Rare and usually fatal disorder Wikipedia Disambiguation

Viral disease affecting human brains Wikidata

A rare brain and spinal cord disease caused by a virus and usually seen only in immunocompromised individuals, such as those with HIV. Symptoms vary, but include loss of muscle control, paralysis, blindness, speech problems, and an altered mental state. This disease often progresses rapidly and may be fatal. PML is considered an AIDS-defining condition in people with HIV. OmegaWiki