[A case of herpetic meningoencephalitis associated with massive intracerebral hemorrhage during acyclovir treatment: a rare complication].

We report a case of a 35-year-old female with herpetic meningoencephalitis confirmed by polymerase chain reaction and immunohistochemical study for herpes simplex virus-1 accompanied with a massive intracerebral hematoma as a complication. A hematoma localized at the medial temporal lobe and the medial frontal lobe occurred on the 11th day after initiation of acyclovir treatment. She subsequently required emergency surgery for temporal lobectomy, as well as hematoma and external decompression. Intracerebral hematoma with MR imaging showed gyral pattern along the cortex of the medial temporal lobe and the base of the medial frontal lobe. We speculate that the hemorrhage occurred by rupture of small vessels affected by vasculitis in addition to hypertension caused by increased intracranial pressure. We therefore emphasize the risk of intracerebral hemorrhage at an early stage or during acyclovir treatment, especially during one or two weeks after initiation of the treatment, and the necessity of careful observation during these periods.