Juvenile parkinsonism caused by chronic meningoencephalitis: a clinicopathological study.

After a six-year history of poor concentration, intellectual and growth retardation, and a one-year history of absences, an 11-year-old girl developed parkinsonism and thereafter had a progressive, predominantly extrapyramidal disorder for the next nine years, until her death at age 20. Other clinical features included pyramidal signs, peripheral neuropathy and sideroblastic anemia. Despite a clinical course suggestive of a degenerative condition, the principal findings on examination of the brain were chronic meningitis, brainstem encephalitis and mild diffuse cerebral gliosis. Extensive investigations failed to demonstrate an infective agent, either in life or by post mortem examination.