Epileptic patterns of local cerebral metabolism and perfusion in man determined by emission computed tomography of /sup 18/FDG and /sup 13/NH/sub 3/

Seventeen patients with partial epilepsy had EEG monitoring concurrent with cerebral emission computed tomography (ECT) after /sup 18/F-fluorodeoxyglucose (/sup 18/FDG) and /sup 13/N-ammonia were given intravenously as indicators of local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. In 12 of 15 patients who had unilateral or focal electrical abnormalities, interictal /sup 18/FDG scan patterns clearly showed localized regions of decreased (20% to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization. These hypometabolic zones appeared normal on x-ray computed tomography in all but three patients and were unchanged on scans repeated on different days. In 5 of 6 patients who underwent temporal lobectomy, the interictal /sup 18/FDG scan correctly detected the pathologically confirmed lesion as a hypometabolic zone, and removal of the lesion site resulted in marked clinical improvement. In contrast, the ictal /sup 18/FDG scan patterns clearly showed foci of increased (82% to 130%) LCMR/sub glc/, which correlated temporally and anatomically with ictal EEG spike foci and were within the zones of interictal hypometabolism (3 studies in 2 patients). /sup 13/NH/sub 3/ distributions paralleled /sup 18/FDG increases and decreases in abnormal zones, but /sup 13/NH/sub 3/ differences were of lesser magnitude. When the relationship ofmore » /sup 13/NH/sub 3/ uptake to local blood flow found in dog brain was applied as a correction to the patients' /sup 13/NH/sub 3/ scan data, local alterations in perfusion and glucose utilization were usually matched, both in the interictal and ictal states.« less