VARIABILITY OF PRESENTATION IN MEDIAL TEMPORAL-LOBE EPILEPSY - A STUDY OF 30 OPERATED CASES

Introduction - To evaluate the homogeneity of patients operated on for MTLE. Material and methods - 30 consecutive patients prospectively in vestigated with clinical, EEG, neuropsychology, MRI, FDG-PET criteria and eventually intracranial EEG, who underwent antero-medial temporal resection (follow-up: 24 months). Results - Clear and well-lateralised MTLE was non-invasively ascertained in 22 patients (73%). Eight patie nts (27%) had a less pure presentation due to divergent scalp EEG feat ures (bitemporal, widespread or extratemporal), unusual auras or absen ce of MRI-based hippocampal sclerosis or FDG-PET hypometabolism. They were explored by invasive monitoring which confirmed medial temporal o rigin of seizures. Outcome was excellent in 95% of the pure cases (Eng el's class I) and less favorable in the more difficult ones (65% of cl ass I). Conclusions - MTLE criteria, including the strong contribution of brain imaging, permit to select accurately a large percentage of p atients. However a consistant number of patients present a less pure p resentation suggesting more complex epileptogenic networks.