PET with 11C-deuterium-deprenyl and 18F-FDG in focal epilepsy

Objectives - This study compares positron emission tomography (PET) using C-11-deuterium-deprenyl (DED) with PET using F-18- fluorodeoxyglucose(F-18-FDG) for examining epileptogenic regions in patients with focal epilepsy. Material and methods - Twenty-three patients undergoing evaluation for epilepsy surgery were subjected to PET with DED. Fourteen patients had mesial temporal lobe epilepsy (TLE) and 9 patients had seizures of neocortical origin. In addition, 6 healthy control subjects were examined. Pixel-by-pixel analysis was used to generate graphical images of tracer distribution volume (intercept) and the accumulation rate (slope). Asymmetries with respect to relative intercept and slope were compared in patients with temporal lobe epilepsy (TLE), in patients with extra-temporal lobe epilepsy (exTLE), and in the control subjects. The results were compared with F-18-FDG-PET. Results - Among the patients with TLE, significant differences between the epileptogenic and the contralateral lobe were found with DED intercept and FDG-uptake. No significant differences were found with DED slope. The exTLE and the control groups showed no significant differences between sides or lobes. Conclusions - This study indicates that PET with C-11-deuterium-deprenyl is a useful method for identifying TLE and is equivalent to PET with F-18-FDG in this sense. The method has little localizing value in seizures originating from neocortical structures.