Also known as PML, an aggressive infection of brain cells caused by the JC virus (JCV). In PML, JCV infects and destroys the cells that produce myelin, the substance that forms the sheath that normally surrounds and protects nerve cells. This disease develops most frequently in people who have compromised immune systems as a result of HIV (human immunodeficiency virus) infection or long-term chemotherapy for cancer. The occurrence of PML in the presence of HIV constitutes a diagnosis of AIDS (acquired immunodeficiency syndrome).
A disease characterized by the presence of widespread demyelinating lesions of the brain, brainstem, and/or cerebellum. It is caused by infection with polyoma JC virus. PML is usually associated with chronic, immune suppressing illnesses, such as AIDS, and some lymphomas or leukemias. Clinical findings include aphasia, ataxia, blindness, dementia, dysarthria, and eventual coma. The disease is sometimes diagnostically confused with multiple sclerosis.