WIDESPREAD GLUCOSE HYPOMETABOLISM IN PATIENTS WITH HIPPOCAMPAL ATROPHY - EVALUATION WITH F-18 FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY

Positron emission tomography (PET) with F-18-fluorodeoxyglucose was pe rformed to measure the interictal local cerebral metabolic rate for gl ucose (ICMRGlc) in 18 patients observed to have hippocampal atrophy (H A) on magnetic resonance imaging (MRI). Ln all patients, the MRI showe d unilateral atrophy of the hippocampus, and the side showing HA was i psilateral to the EEG lateralization. PET scans were obtained in a sem icoronal plane at an angle of -30 degrees to the orbitomeatal line, ap proximately -60 degrees to the long axis of the temporal lobe. The met abolic asymmetry was compared with the frequency of epileptic seizures , duration of illness, and intellectual deficit. The absolute values o f ICMRGlc (mg/min/100g) in the hippocampus, extrahippocampal temporal lobe, and frontal lobe were significantly lower on the side ipsilatera l to the epileptic focus than on the contralateral side. In patients w ith frequent seizures, there were greater asymmetry of the ICMRGlc in the extrahippocampal temporal lobe and less in the hippocampus, sugges ting that the ipsilateral temporal lobe and contralateral hippocampus were affected by repeated seizures. In conclusion, in patients with pr esumed unilateral temporal lobe epilepsy and HA, PET studies demonstra ted widespread glucose hypometabolism in extrahippocampal areas, and t he semicoronal scan was useful in its evaluation. (C) 1997 by Elsevier Science Inc. All rights reserved.