Comparison of Electroencephalography, Neuroimaging Studies and Surgical Outcome between Mesial and Neocortical Temporal Lobe Epilepsies

Kim, Kwang Soo; Cole, Andrew J

Abstract

PURPOSE: To compare the diagnostic value of electroencephalography (EEG), MRI and PET studies and surgical outcome in patients with medically refractory temporal lobe epilepsy due to hippocampal sclerosis (HS) versus temporal lobe lesions (TLL).
METHODS
Records of 122 consecutive patients who underwent surgery for epilepsy from January 1993 to April 2000 were retrieved from the MGH Epilepsy Surgery Database. Fifty eight patients with temporal lobe epilepsy due to pathologically proven HS or TLL were identified and presurgical interictal and ictal EEG, MRI, and 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG)-PET data and surgical outcome were reviewed. Patients with dual or normal pathology were excluded. Pathologically proven HS was present in 32 patients, and 26 patients has temporal lobe lesions (cortical dysplasia in 6 patients, vascular malformation in 6, gliomas in 5, DNET in 4, heterotopia in 1, other pathologies in 4). Comparisons of the diagnostic value of EEG, MRI and FDG-PET studies were performed in 43 patients who were seizure-free after epilepsy surgery. Among 43 patients, HS was in 24 patients and TLL in 19.
RESULTS
The occurrence of abnormal interictal and ictal EEG, MRI and FDG-PET findings in the side of operation was not significantly different between patients with HS and with TLL respectively. There was no significant difference in at least one year follow-up surgical outcome between the two groups.
CONCLUSIONS
Diagnostic value of presurgical interictal and ictal EEG, MRI and FDG-PET findings, and surgical outcome were not different in patients with mesial versus neocortical temporal lobe epilepsies.