<unk>  <unk>  is a rare and often fatal viral disease characterized by<unk>  damage (-pathy) or inflammation of the white matter (leuko-) of the brain (-encephalo-) at multiple locations<unk> . It is caused by the JC virus, which is normally present and kept under control by the immune system. The JC virus is harmless except in cases of weakened immune systems. In general,<unk>  has a mortality rate of 30–50% in the first few months, and those who survive can be left with varying degrees of neurological disabilities.<unk>  occurs almost exclusively in patients with severe immune deficiency, most commonly among patients with acquired immune deficiency syndrome (AIDS), but people on chronic immunosuppressive medications including chemotherapy are also at increased risk of<unk> , such as patients with transplants, Hodgkin's lymphoma, multiple sclerosis, psoriasis, rheumatoid arthritis, and other autoimmune diseases.
Progressive multifocal leukoencephalopathy
Toxic leukoencephalopathy
Tuberculous meningitis
Granulomatous meningoencephalitis
Herpesviral encephalitis
Malignant multiple sclerosis
Drug-induced aseptic meningitis
Polioencephalitis