Influence of age and location of ictal onset on postoperative outcome in patients with localization-related epilepsy

Introduction. Localization-related epilepsy is a significant concern for the middle-aged and older population given the lesser cognitive reserve and the greater likelihood of adverse systemic antiepileptic drug effects. Epilepsy surgery for this age group has the potential for greater postoperative morbidity and mortality, a protracted rehabilitation with its associated economic burden, progressive cognitive and memory decline and a lesser chance of becoming seizure-free after the procedure. Methods. A retrospective institutional archival review of 120 patients with medically refractory partial epilepsy of both temporal and extratemporal epilepsy was performed. Comparative assessments for seizure cessation and neuropsychological effects were made for those younger and older than 50 years and those with epilepsy durations of greater and less than 20 years. Results. A comparison of surgical outcomes by age group identified that Engel Class I outcomes were attained in 26 of 35 (74%) patients in the older group compared with 49 of 85 (58%) patients in the younger group (p = 0.087). Of the 11 patients aged 60 years or older, 91% attained an Engel Class I outcome, significantly higher than those under 60 years (60%; p = 0.041). Stratification by age of the entire group, otherwise, demonstrated no significant differences by Engel class outcome. Considering both transient and permanent disabilities, the overall complication rate was 14.2% and was similar in patients less than 50 years of age (15.3%) and those aged 50 years or greater (11.4%; p = 0.58). Verbal memory decline was more notable in the older population and for those with epilepsy duration of greater than 20 years. Conclusion. This study demonstrates that epilepsy surgery in the older population has similar seizure-free outcomes and complications when compared with younger patients for both mesial temporal and extratemporal origins. Caution regarding postoperative memory decline in the older population must be stressed.