title: Progressive multifocal leukoencephalopathy.
mesh_terms: D001921:Brain / Q000382:microbiology; D003711:Demyelinating Diseases / Q000382:microbiology*; D006801:Humans; D007968:Leukoencephalopathy, Progressive Multifocal / Q000382:microbiology; D014780:Viruses / Q000302:isolation & purification