Herpes Simplex Virus Encephalitis: An Unexpected Outcome in a Polytrauma Patient

An 84-year male was brought in the emergency after a road traffic accident leading to polytrauma with deteriorating consciousness. Prolonged unexplained unconsciousness led to cerebrospinal fluid examination. The polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) was found to be positive for HSV-1 DNA. The patient was started on intravenous acyclovir and the consciousness level of the patient improved gradually. In this case, encephalitis was not suspected initially, because of the multiple traumatic injuries that needed management. Moreover, no features suggestive of encephalitis were present at the time of presentation, except for the nonspecific symptom of drowsiness at the time of the accident. The patient was also diabetic and had chronic kidney disease as predisposing factors. It was primarily encephalitis which led to impaired consciousness that resulted in the road traffic accident in a very unlikely situation, i.e., hit by an ambulance inside the hospital. The reasons to suspect herpes simplex virus encephalitis (HSE) in this case were unexplained worsening level of consciousness, CSF findings suggestive of viral encephalitis along with highly deranged alanine aminotransferase (ALT) levels. This case highlights the importance of keeping a high index of suspicion for viral encephalitis in patients with risk factors, even in such a scenario of polytrauma.