HSV-1 encephalitis is one of the most common viral encephalitides in the United States. Symptoms include headache, fever, changes in mental status, seizures, and other focal neurological deficits. We describe a patient with a history of HSV-1 encephalitis 30 years prior who presented with HSV-1 encephalitis affecting the contralateral temporal lobe.

An 81-year-old woman with a history of HSV-1 encephalitis 30 years ago affecting the left temporal lobe was brought to the Emergency Room with convulsions and non-responsiveness. Non-contrast head CT showed an area in the anterior left temporal horn consistent with encephalomalacia. She was treated with IV lorazepam and loaded with levetiracetam and fosphenytoin. The convulsions stopped but patient remained unresponsive except to noxious stimuli. Patient developed fever of 38.4° Celsius. CSF profile showed 86 nucleated cells/µL (1% neutrophils, 86% lymphocytes), 6 RBCs/µL, 122 mg/dL protein, and 38 mg/dL glucose. Empiric broad spectrum antibiotics and IV acyclovir were started. Video EEG showed waxing and waning irregular polymorphic slowing and recurrent spikes/sharps/epileptiform discharges on the right in broad distribution occurring rhythmically and semi-rhythmically. Brain MRI with and without gadolinium showed T2/FLAIR hyperintensity involving the anterior right temporal lobe. On day five, HSV-1 PCR from the CSF returned positive. Despite treatment with multiple antiepileptic agents, patient had minimal clinical improvement and was transitioned to hospice care.

Recurrent HSV-1 encephalitis is rare. It is thought that HSV-1 can persist in the brain parenchyma in a latent state after initial recover. Often the same area of the brain will become re-involved. To our knowledge, this is the first case report of a patient who developed HSV-1 encephalitis initially affecting one temporal lobe who then developed HSV-1 encephalitis in the contralateral temporal lobe 30 years later.