Meningoencephalitis: an atypical presentation of herpes simplex type 2 central nervous system infection.

Encephalitis is the best recognized form of central nervous system (CNS) infection with the herpes simplex virus. We present a case of meningoencephalitis with a benign course caused by herpes simplex virus type 2. The patient had no focal abnormalities on either brain magnetic resonance imaging scan or electroencephalogram. The cerebrospinal fluid profile was that of aseptic meningitis, with a lymphocytic pleocytosis. The clinical spectrum of herpes simplex infections in the CNS is broad. Specifically, herpes simplex type 2 can cause a benign meningoencephalitis with scant focal findings, in addition to the known encephalitis and more recently recognized benign recurrent lymphocytic meningitis.