A REVIEW ARTICLE ON HERPES SIMPLEX ENCEPHALITIS

Abstract: Herpes Simplex encephalitis (HSE) is a life threatening outcome of Herpes simplex virus (HSV) infection of the central nervous system (CNS). HSV accounts for 2-5 percent of all cases of encephalitis. One third of cases occur in those younger than 20 years old and one half in those older than 50 years old. Clinical diagnosis is recommended in the encephalopathic, febrile patients with focal neurological signs. However, the clinical findings are not pathogonomic because numerous other diseases of CNS can mimic HSE. Diagnosis should be confirmed based on medical history, analysis of cerebrospinal fluid (CSF) for protein and glucose contents, the cellular analysis and identifying the pathogens by serology and Polymerase Chain Reaction (PCR) amplification . The diagnostic gold standard is the detection of HSV DNA in the cerebrospinal fluid by PCR. But negative results need to be interpreted regarding the patients clinical signs and symptoms and the time of CSF sampling. Spike and slow wave patterns is observed in Electroencephalogram (EEG). Neuroimaging, especially Magnetic Resonance Imaging (MRI) is essential for evaluating the patients, which shows temporal lobe edema or hemorrhage. All patients with HSE should be treated by intravenous Acyclovir (10mg/kg q8hr for 14-21 days). After completing therapy, PCR of the CSF can confirm the elimination of replicating virus, assisting further management of the patient.