Toxic pediatric parkinsonism: report of a child with metabolic studies and response to treatment.

We successfully treated a child with parkinsonism secondary to cytosine arabinoside with levodopa/carbidopa and attempted to elucidate the pathogenesis of the disorder by sequential analysis of cerebrospinal fluid biogenic amines, sequential magnetic resonance imaging, and fluorodopa positron emission tomography, which revealed both permanent and reversible biochemical and structural alterations. The parkinsonian disorder resolved in 9 months. Metabolic changes and structural abnormalities on imaging studies were chronologically correlated with the clinical course.