[Herpetic encephalitis in childhood: a diagnosis which should not be forgotten].

Herpes simplex encephalitis is a serious infection of the nervous system, causing death or considerable neurological morbidity in infants and children. Rapid diagnosis and prompt institution of antiviral therapy is essential. Prodromal manifestations (fever, headache, and behavioural disturbances) can be quite unspecific. Focal neurological signs, seizures (focal or generalised) and coma appear subsequently. Electrophysiologic studies and neuroimaging can be normal or show non specific changes, particularly in this age group. After the 1990 s polymerase chain reaction (PCR) examination of the LCR has become the gold standard for diagnosing herpes simplex encephalitis, virtually replacing cerebral biopsy with high sensitivity and specificity. The authors present the acute presentation and follow up of four children aged 3 months 12 years, admitted between 1997 and 2000 with the diagnosis of herpes simplex encephalitis. Clinical presentation, electroencephalogram and neuroimaging studies are discussed. Diagnostic confirmation was obtained with serologic methods in one child and with PCR in the remaining three. Evolution was severe, with a movement disorder that responded dramatically to tetrabenazine in one child, severe neurological sequel with refractory epilepsy in two children and one death with cerebral hemorrhage during the acute stage of disease.