Abstracts

Rationale: Although surgery has been proven effective in the treatment of pharmacoresistant mesial temporal lobe epilepsy (MTLE), controversy exists regarding the optimal extent of resection for seizure and neuropsychological outcome. Methods: A retrospective study was performed of all patients who have undergone an anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SAH) for MTLE at Notre-Dame Hospital from January 1980 to July 2007. All patients underwent a comprehensive presurgical evaluation including complete neuropsychological testing before and after surgery. Seizure outcome was evaluated using the Engel classification scale. Results: During the study period, 142 patients underwent temporal lobe surgery for refractory TLE. There were 116 ATL and 26 SAH. In this series, 62% (n=16) of SAH and 61% (n=70) of ATLs were operated on the left side. Hippocampal sclerosis (HS) was diagnosed at pathology in 48% (n=56) of ATL and 85% of SAH (n=22). Patients used an average of 4.4 (range 2-12) antiepileptic drugs before surgery. After a mean follow-up of 4.3 years, a favorable seizure outcome (Engel I and II) was noted in 91.5% and 85% of patients who had undergone ATL and SAH, respectively. However, only 28% of the patients who had undergone ATL and 46% of those who had undergone an SAH were seizure free (Engel Class Ia). Rate of quadranopsia was higher in ATL (31%) than in SAH (12%). Language difficulties occurred in 17% and 12% of patients undergoing ATL and SAH, respectively. Subjective memory impairment rate at office visit was 12% in patients undergoing ATL (n=14) and SAH (n=3). Detailed neuropsychological outcome data is currently being assessed and will be shown at the meeting in December 2010. Conclusions: These results add to the limited existing data suggesting that long-term seizure outcome is comparable following ATL and SAH for MTLE.