AbstractA 5‐year‐old boy, with a history of fever beginning 15 days after a vaccination for measles, developed a rigid‐akinetic syndrome 3 days after the fever began. A spinal tap obtained 1 week after the onset of fever showed pleocytosis with a monocellular pattern. A CT scan of the head and EEG did not disclose any abnormality. An MRI performed 3 months after the event, however, showed clear‐cut evidence of bilateral substantia nigra lesions, suggesting secondary gliosis. The response to levodopa was good, but adverse reactions appeared early. The child is now 7 years old. Bromocriptine, deprenyl, and levodopa have produced a remarkable improvement of the parkinsonian f