Viruses and Progressive Multifocal Leukoencephalopathy

There has recently been an increasing interest in the relation between viruses and chronic degenerative diseases of the brain. Within the past few years, measles virus has been found to be associated with subacute sclerosing panencephalitis and transmissible agents have been isolated from patients with Kuru and Creutzfeldt—Jakob disease (spongiform encephalopathy).Progressive multifocal leukoencephalopathy (PML) is a rare neurological disease characterized by focal demyelinization occurring around blood vessels, particularly veins. A unique feature of this disease is a peculiar reaction on the part of the glial supporting cells of the central nervous system. Individual astrocytes, which from their distribution and . . .