Cerebellar mutism in pediatric acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is a demyelinating process affecting multiple areas of the central nervous system, frequently including the cerebellum. Cerebellar insult may lead to absence of speech or cerebellar mutism. Cerebellar mutism often occurs in young children after posterior fossa tumor resection, and generally appears as part of a larger subset of neurobehavioral signs and personality changes known as posterior fossa syndrome. Information on the impact of widespread cerebellar involvement on speech production, behavior, and long-term outcomes in acute disseminated encephalomyelitis is limited. We describe cases of acute disseminated encephalomyelitis with predominantly cerebellar involvement, with specific attention to cerebellar mutism. We conducted a retrospective chart review of children diagnosed with acute disseminated encephalomyelitis between 2005-2009 at a pediatric multiple sclerosis and demyelinating disorders clinic. Of 19 patients diagnosed with acute disseminated encephalomyelitis, six (32%) manifested primary cerebellar involvement. Of these six, four (67%) exhibited acute language disturbance, with three (50%) exhibiting mutism. The three patients with cerebellar mutism experienced protracted speech and language deficits after follow-ups from 6 months to 4 years. Widespread cerebellar involvement in acute disseminated encephalomyelitis may result in cerebellar mutism, in addition to persistent neurocognitive and behavioral problems.