Leukoencephalopathy, Progressive Multifocal

**Definition:** An opportunistic viral infection of the central nervous system associated with conditions that impair cell-mediated immunity (e.g., ACQUIRED IMMUNODEFICIENCY SYNDROME and other IMMUNOLOGIC DEFICIENCY SYNDROMES; HEMATOLOGIC NEOPLASMS; IMMUNOSUPPRESSION; and COLLAGEN DISEASES). The causative organism is JC Polyomavirus (JC VIRUS) which primarily affects oligodendrocytes, resulting in multiple areas of demyelination. Clinical manifestations include DEMENTIA; ATAXIA; visual disturbances; and other focal neurologic deficits, generally progressing to a vegetative state within 6 months. (From Joynt, Clinical Neurology, 1996, Ch26, pp36-7)

**Tree numbers:** - C01.207.245.340.500 - C01.207.399.750.500 - C01.925.182.525.500 - C01.925.256.721.500 - C01.925.839.550 - C10.228.140.430.520.750.500 - C10.228.140.695.750 - C10.228.228.245.340.500 - C10.228.228.399.750.500 - C10.314.450 - C10.586.250.520.750.500

**Synonyms:** - Encephalitis, JC Polyomavirus - Progressive Multifocal Leukoencephalopathy - JC Polyomavirus Encephalopathy