A 76-year-old man who developed febrile unconsciousness with magnetic resonance imaging findings indicating encephalitis.

This article focuses on the case of a 76-year-old man who developed febrile unconsciousness with magnetic resonance imaging findings indicating encephalitis. The old man who had suffered from acute hepatitis during his childhood, underwent a medical examination that revealed abnormal liver function. With these findings combined, a diagnosis of encephalitis was made, although the lumbar puncture could not be performed because of the bleeding tendency. In spite of immediately started acyclovir, the patient's condition deteriorated rapidly, resulting in deep coma.