Postinfectious encephalomyelitis with localized basal ganglia involvement.

The diagnosis of postinfectious encephalomyelitis with symmetric lesions in the basal ganglia was confirmed by magnetic resonance imaging in 2 patients. A 7-year-old patient experienced severe dystonia and hyperreflexia; magnetic resonance imaging demonstrated bilateral lesions in the putamina and basis pontes. The other patient, a 2-year-old female, manifested hypotonia, facial grimacing, and athetosis. Symmetric lesions in the globus pallidus and substantia nigra were demonstrated by imaging studies. The nature and monophasic course of illness in these 2 patients, as well as the symmetric involvement of specific regions of the basal ganglia, may result from an immune-mediated postinfectious demyelinating process.