Herpes simplex encephalitis simulating systemic embolism.

A case of herpes simplex virus encephalitis is described in a patient known to suffer from chronic atrial fibrillation and whose clinical symptoms suggested cerebral embolism of cardiac origin. The final diagnosis was based on the presence of herpes simplex virus type 1 antibodies in the cerebrospinal fluid and a significant rise in antibody titers in the serum. The patient regained consciousness after craniotomy and treatment with idoxuridine. The case emphasizes that the possibility of herpetic encephalitis should be considered in patients presenting with typical signs of a cerebrovascular accident.