Progressive multifocal leukoencephalopathy is caused by

(D) Papova virus # Progressive multifocal leukoencephalopathy is a viral encephalitis caused by a polyomavirus (Papova virus or JC virus, totally unrelated to Creutzfeldt-Jakob disease) because the virus preferentially infects oligodendrocytes, demyelination is its principal pathologic effect.> Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage (-pathy) or inflammation (-His) of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal).> It occurs almost exclusively in people with severe immune deficiency, e.g. transplant patients on immunosuppressive medications, or AIDS patients.> The cause of PML is a type of polyomavirus called the JC virus (JCV).