Recurrent herpes simplex encephalitis: recovery of virus after Ara-A treatment

A 54-year-old man developed clinical findings consistent with herpes simplex virus (HSV) encephalitis. These signs included an abrupt onset of focal central nervous system disease, cerebrospinal fluid pleocytosis, localized electroencephalographic abnormalities, and a computerized tomographic scan showing right temporal lobe involvement. Treatment with adenine arabinoside (Ara-A) resulted in improvement. Two months later he again became confused, and a left hemiparesis developed. Although biopsy revealed extensive necrosis and inflammatory response, HSV antigens and herpesvirus particles were not detected. Culture of biopsy tissue yielded HSV type 1 only after 18 days. A second course of Ara-A was administered but the patient failed to improve and died four months later. Extensive inflammatory necrosis of both temporal lobes involving gray and white matter was found. Cultures were negative for HSV. The recovery of virus from our patient during the second encephalitic episode should raise concerns regarding the efficacy of Ara-A treatment and the role of the virus in recurrent disease. In addition, the importance of maintaining biopsy tissue in culture for prolonged periods is emphasized.