A case of surgically treated acute cerebellitis with hydrocephalus.

We report a pediatric case of acute cerebellitis with hydrocephalus requiring emergency placement of external ventricular drainage. A 7-year-old boy presented with acute development of headache, nausea and vomiting. Magnetic resonance (MR) examination revealed obstructive hydrocephalus and marked bilateral cerebellar swelling on T2-weighted imaging. After the placement of external ventricular drainage, symptoms of intracranial hypertension promptly improved, and other clinical and radiological abnormalities gradually resolved following intravenous injection of corticosteroids. Surgical treatment and timing in the treatment of acute cerebellitis are discussed.