HERPES ENCEPHALITIS IN MALAYSIAN CHILDREN

Objectives: To define the clinical spectrum of herpes simplex virus (HSV) encephalitis amongst Malaysian children.

Methods: Retrospective data was collected from children who were diagnosed with herpes encephalitis, from January 2003 till October 2005. Children who presented with a neurological syndrome and had either a positive polymerase chain reaction (PCR) for HSV DNA in the cerebrospinal fluid (CSF) and/or positive serological tests for HSV in serum were included. Results: Fifteen children (ages 2 months-9 years) were included, Twelve children were PCR positive. The three children <1 year age presented with acute or subacute meningitis. Older children presented with complex febrile seizures (three children), febrile status epilepticus (four), or recurrent afebrile seizures over days or weeks (three), with subsequent expressive language difficulties (100%), dysphagia (70%) and increased somnolence (40%) on recovery. Four of these children progressed to encephalopathy, three of whom were treated late and went on to develop akathisia, dystonia and choreoathetosis. A further two children presented with fever and cognitive regression alone. Focal abnormalities were seen on EEG in seven (47%) children, and typical MRI abnormalities in five (30%) children. Twelve children were given acyclovir for two to three weeks. Outcome was excellent in children without encephalopathy and in those treated early (<2 two weeks), though two infants developed a second episode of aseptic meningitis. Two children expired as a result of nosocomial septicaemia.

Conclusion: PCR analysis for HSV has led to the recognition of a wider clinical spectrum in HSV encephalitis. The diagnosis should be considered in young infants with meningitis, in older children with acquired language difficulties or dysphagia following a recent seizure, and in previously normal children who show sudden cognitive regression.