Acute post-infectious cerebellar ataxia due to co-infection of human herpesvirus-6 and adenovirus mimicking myositis.

Acute cerebellar ataxia (ACA) is a relatively common neurological disease in children. Most common types of ACA are acute post-infectious (APCA) and acute disseminated encephalomyelitis (ADEM). Less common but important causes include opsoclonus-myoclonus syndrome (OMS) and acute cerebellitis. Cerebellar neoplasms and acute hydrocephalus are additional causes of paediatric ataxia. APCA is the most common cause of ACA in children, comprising about 30-50% of total cases. This is a report about an immunocompetent 4-yrs-old male affected by APCA, due to co-infection by human herpesvirus-6 (HHV-6) and adenovirus, with symptoms mimicking myositis.