A SUCCESSFULLY TREATED CASE OF HERPES SIMPLEX ENCEPHALITIS

: Herpes simplex encephalitis is a potentially lethal infection that should be recognised as soon as possible. The combination of clinical history and examination, brain computed tomography or magnetic resonance imaging and lumbar puncture has been used to establish a diagnosis.We present a case of 20 year old male presenting with fever, headache and later developed focal neurological deficit. His CSF examination showed no cells. His CT brain showed temporal lobe hypodensity and his MRI revealed temporal lobe hyperintense signals in T2 weighted images characteristic of herpes encephalitis. But his CSF PCR for HSV was negative though repeated twice.There was no elevation of oligoclonal antibodies specific to HSV in CSF after 1week. The patient was successfully treated with acyclovir.Although we did not prove the presence of the agent microbiologically at the clinical onset of the disease, the CT and MRI findings and the dramatic response to acyclovir therapy are suggestive of a diagnosis of herpes simplex encephalitis . CSF PCR for herpes virus is highly sensitive and specific and remains the standard for diagnosing herpes encephalitis. Clinicians should be aware of the pitfalls of CSF PCR testing, specifically falsenegative results.