Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease characterized by progressive damage (-pathy) or inflammation of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal).
It occurs almost exclusively in people with severe immune deficiency, such as transplant patients on immunosuppressive medications, receiving certain kinds of chemotherapy, receiving natalizumab (Tysabri) for multiple sclerosis, on long-term efalizumab (Raptiva) for psoriasis, or have AIDS.
It is caused by a virus, the JC virus, which is normally present and kept under control by the immune system. Immunosuppressive drugs prevent the immune system from controlling the virus.
Read more about Progressive Multifocal Leukoencephalopathy: Cause, Contributing Causes, Pathogenesis, Symptoms, Diagnosis, Treatment
Famous quotes containing the word progressive:
“There is, I think, no point in the philosophy of progressive education which is sounder than its emphasis upon the importance of the participation of the learner in the formation of the purposes which direct his activities in the learning process, just as there is no defect in traditional education greater than its failure to secure the active cooperation of the pupil in construction of the purposes involved in his studying.”
—John Dewey (1859–1952)