Complicated acute cerebellitis with obstructive hydrocephalus and tonsillar herniation in a child.

Acute cerebellitis (AC) is a rare inflammatory syndrome presenting as cerebellar dysfunction, seen more frequently in children. AC can have a variable course with features of cerebellar dysfunction, raised intracranial pressure and neurological deficits, and can sometimes even be potentially fatal due to complications such as obstructive hydrocephalus and brainstem compression, warranting surgical intervention. We report a case of a 12-year-old boy who presented with raised intracranial pressure and ataxia. Imaging with CT and MRI showed AC with obstructive hydrocephalus and tonsillar herniation. He was managed with medications for raised intracranial pressure and with ventriculoperitoneal shunt, and he recovered completely over a period of 2 weeks. Imaging has an important role in the diagnosis of AC and in differentiating it from acute cerebellar ataxia, which has a more benign course. It is crucial to diagnose and promptly manage the rarely occurring but life-threatening complications of AC.