Bilateral oedema of the basal ganglia in an echovirus type 21 infection: complete clinical and radiological normalization.

A 4-year-old girl with bilateral striatal oedema in association with an echovirus type 21 infection is reported. In the course of a prolonged upper respiratory-tract infection, the patient developed muscular hypotonia, resting tremor, ataxia, sleepiness, hyperaesthesia, and indistinct speech. T2-weighted cranial MRI revealed bilateral oedema of the basal ganglia and the cerebellar peduncles. At follow-up after 3 months MRI changes and clinical symptoms had fully resolved.