Sequential positron emission tomographic evaluations of brain metabolism in acute herpes encephalitis.

This first known positron emission tomography report on metabolic changes in acute herpes simplex virus (HSV-1) encephalitis demonstrates focal hypermetabolism in areas of cerebral cortex adjacent to actively inflamed hippocampus acutely infected with HSV-1. When neuropsychiatric symptoms recurred in a previously healthy 61-year-old patient 1 month after recovering from acute HSV-1 encephalitis, repeat positron emission tomography with fluorodeoxyglucose was helpful in ruling out recurrent active infection by showing marked hypometabolism throughout the previously infected temporal lobe.