This 30-year-old white male experienced a generalized tonic-clonic seizure and was subsequently started on a course of Dilantin. He did well, but later developed a headache lasting over a week, which was associated with tonic-clonic seizures, fever, and--toward the end of this period--ataxia. The patient improved and returned to work, but the headache returned. A lumbar puncture was then performed which showed 22 cells/cmm mm³ (all lymphocytes), protein of 88 grams/L, and a glucose level of 49 mg/dL (with a simultaneous serum glucose of 83 mg/dL). These findings were compatible with a viral infection. Despite therapy, the patient had another seizure and again developed fever. At that time, a brain biopsy was performed which showed herpetic encephalitis. Despite aggressive antiviral therapy the patient died.