Introduction: Temporal lobectomy is an effective intervention for patients with refractory seizures originating in the temporal lobe. Outcomes have been evaluated extensively in the years immediately following surgery for epilepsy, but the literature on long-term outcome is less robust.

Methods: Records of patients receiving an anterior medial temporal lobectomy by the senior author (DDS) from the years 2000 – 2014 were queried from the Yale Epilepsy Center database. Engel and ILAE outcomes were assigned based on chart review for 1-5 and =10 year follow-ups. Pathology was determined by postoperative pathology report.

Results: 114 patients met inclusion criteria. Pathologic diagnosis showed 74 patients with mesial temporal sclerosis (MTS), 25 neoplasms, 5 malformations of cortical development (MCD), 3 vascular malformations (VM), 1 infarct and 13 patients with gliosis as their only pathologic diagnosis. Preliminary analysis shows freedom from disabling seizures in =75% through 10 years follow-up. Of patients whose seizures recurred, over half recurred in the first post-operative year, with the rate of recurrence slowing dramatically after year 3. Of patients who recurred in post-operative year 1, 27% lacked a defined lesion, with pathology revealing gliosis. Kaplan-Meyer analysis of time to first disabling seizure shows a significant difference between patients with non-lesional pathology (gliosis) compared to those with a defined lesion (MTS, neoplasm, MCD, VM, or infarct).

Conclusions: In this retrospective, single-center, single surgeon series, the most common pathology treated with anterior medial temporal lobectomy was mesial temporal sclerosis. Preliminary analysis suggests that the majority of patients treated with anterior medial temporal lobectomy will achieve stable freedom from disabling seizures through 10 years follow-up. Rate of seizure recurrence was highest in the first 3 postoperative years. Patients with non-lesional pathology appear to have shorter time to first seizure than lesional pathologies. Next steps include analysis of preoperative seizure localization and postoperative AED regimen.

Patient Care: This research allows physicians and patients to better understand results that can be expected after a common form of epilepsy surgery. This line of research is aimed at eventually delineating why some patients fail epilepsy surgery.

Learning Objectives: From the results of this study, participants should 1) have evidence for good seizure outcome 10 years after temporal lobectomy, 2) understand that the rate of recurrence drops after the third post-operative year, and 3) have evidence that non-lesional pathology is associated with post-operative seizure recurrence.

References: Wiebe S, Blume WT, Girvin JP, et al. A randomized, controlled trial of surgery for temporal-lobe epilepsy. N Engl J Med 2001;345:311–8. Spencer SS, Berg AT, Vickrey BG, et al. Predicting long-term seizure outcome after resective epilepsy surgery: The Multicenter Study. Neurology 2005;65:912–8. Yoon HH, Kwon HL, Mattson RH, et al. Long-term seizure outcome in patients initially seizure-free after resective epilepsy surgery. Neurology 2003;61:445–50. Spencer SS, Berg AT, Vickrey BG, et al. Initial outcomes in the Multicenter Study of Epilepsy Surgery. Neurology 2003;61:1680–5.