EN
A case of sixteen-year-old boy with initial herpes simplex virus (HSV) and Epstein-Barr virus (EBV) encephalitis is reported. Herpesviruses are often found in cerebrospinal fluid (CSF) along with EBV. After eradication of HSV in CSF in this case, a positive polymerase chain reaction (PCR) to EBV in CSF remained along with a severe clinical picture (segmental myoclonus and Klüver-Bucy syndrome) and worsening of brain magnetic resonance imaging (MRI) findings. Neurological and psychological improvement occurred after treatment with intravenous immunoglobulin.