Home > Encyclopedia of Neurological Disorders > Progressive Multifocal Leukoencephalopathy

Definition

Progressive multifocal leukoencephalopathy is a rare, fatal disease of the white matter of the brain that almost solely strikes individuals who already have weakened immune systems.

Description

In progressive multifocal leukoencephalopathy, myelin (the substance that wraps around nerve fibers, providing insulation and speeding nerve transmission) is progressively destroyed. Although the disease is caused by a very prevalent virus (called JC virus), it only develops in individuals who are immunocompromised (have weakened immune systems).

Multiple areas of the brain are affected by the demyelination associated with progressive multifocal leukoencephalopathy. Additionally, other abnormalities and bizarre cells take up residence within the brain, causing destruction of normal brain tissue and impairing normal function.

Demographics

The causative virus in progressive multifocal...