[Acute encephalitis: report on 32 consecutive pediatric cases observed in one hospital]

We report 32 cases of acute encephalitis consecutively hospitalized in one hospital, from January 1991 to December 2002. The causative agent was identified in 26 cases (81%). The main associated viruses were varicella-zoster (10 children; 31%), Herpes simplex (6 children; 19%), and enteroviruses (4 children; 13%). At the acute phase, the most relevant biological findings were electroencephalogram results and CSF analysis. The initial encephalic imaging was primarily helpful to exclude other acute neurological diseases whereas long-term imaging was a prognostic factor for necrotizing encephalitis. The microbiological diagnosis required several days or weeks to be determined. It did not influence the initial management. In addition to the 6 cases of herpetic encephalitis, 19 children (78% altogether) were then treated by acyclovir before a definitive diagnosis was made. Twenty-two children (69%) had a favorable outcome, 2 (6%) had moderate sequels, 2 (6%) had important ones, and 5 (16%) had major ones. One (3%) child died. The outcome was highly dependant on the causative agent and the mechanism of encephalitis. This series gives information on the epidemiology of encephalitis in children in our region over a period of 12 years.