Post-infectious acute cerebellar ataxia in a young adult.

Acute cerebellar ataxia is a clinical syndrome that involves loss of balance and coordination, typically within less than 72 hours. It usually presents in children and rarely affect adults. A woman in her early 20s presented with acute onset dizziness, vertigo, truncal ataxia and dysarthria 2 weeks following an acute viral illness. Cerebral MRI identified evidence of dural enhancement, and positron emission topography brain imaging showed cortical reduction of glucose metabolism, consistent with an encephalopathic process. Lumbar puncture established a normal cerebrospinal fluid protein and glucose, with seven white cells ×106/L. Subsequent investigations identified evidence of a recent Epstein-Bar virus, in keeping with a post-infectious acute cerebellar ataxia syndrome. Following treatment with intravenous methylprednisolone, symptoms resolved gradually over months. While post-infectious acute cerebellar ataxia is rare in adults, it is an important cause of an acute presentation of ataxia that should be recognised by paediatric and adult physicians.