Surgical Treatment for Refractory Temporal Lobe Epilepsy in the Elderly: Seizure Outcome and Neuropsychological Sequels Compared with a Younger Cohort

Abstract

Surgical treatment of refractory temporal lobe epilepsy (TLE) is promising for selected patients, but only little experience has been acquired in operating on older patients, especially with limited resections. We intend to delineate clinical and surgical factors influencing outcome in patients older than 50 years at operation and to compare the results with those of a younger patient cohort. Fifty-two patients older than 50 years were operated on for intractable mesial or combined mesiolateral TLE between 1991 and 2002. The mean age at operation was 55 years, and the mean duration of epilepsy was 33 years. Forty selective amygdalohippocampectomies (33 for hippocampal sclerosis, seven for removal of a mesiotemporal lesion), five lateral temporal lesionectomies plus amygdalohippocampectomy, and seven anterior temporal lobectomies were performed. Eleven (21%) patients had undergone invasive presurgical video-EEG monitoring. The mean follow-up period was 33 months. We compared the results with those of a younger cohort operated on in the same time period. Thirty-seven older patients attained complete seizure control (71% class I), and 10 patients had only rare postoperative seizures (19% class II). Four patients improved >75% (8% class III), and one patient did not improve (2% class IV). The same rate of seizure control was attained by 11 patients older than 60 years at surgery. These results were not significantly different from those in a younger patient group. A trend toward better seizure control was noted in 16 patients with an epilepsy duration of <30 years (all class I or II), and in 20 patients with a seizure frequency of fewer than five seizures per month (all class I or II). No mortality resulted from a total of 65 diagnostic and therapeutic procedures. A 3.8% permanent neurologic morbidity (dysphasia and hemiparesis) was noted. Hemianopia occurred in three (5.9%) patients. Neuropsychological testing revealed low preoperative performances and some gradual further deterioration after surgery. Results of surgery for TLE with mainly limited resections are promising in patients older than 50 years and older 60 years, despite the long seizure history. As expected, the risk of complications is somewhat higher compared with that in a younger control group. The impact of low neuropsychological performance is a concern.