Herpes simplex encephalitis - problems in diagnosis and recent advances

Abstract

Herpes simplex encephalitis (HSE) is an uncommon but serious condition, with an untreated mortality rate of up to 75 percent. Early treatment with acyclovir is both safe and affective and is associated with significant improvement in outcome. However, considerable diagnostic difficulties may be encountered, leading to delay in treatment. Mild forms of herpes simplex encephalitis have been described and our patient may be an example of such a case. A thirteen year old Malay boy presented with 5 days prodromal symptoms of diarrhoea followed by fever and vomiting. He had altered sensorium 2 days prior to admission. Even
though the CSF study and serology for herpes simplex virus were negative, a presumptive diagnosis of HSE was made based on an abnormal EEG and evidence of focality on neuroradiological imaging (SPECT). The patient responded to acyclovir. The problems is diagnosing HSE using routine investigations without brain biopsy is discussed and recent diagnostic advances are highlighted