Abstracts

Rationale: Epilepsy surgery bears certain cognitive risks that are determined by a variety of factors including site of surgery, pre-surgical cognitive functioning, age at seizure onset, and age at surgery. Some literature suggests that undergoing surgery at an older age may bear additional cognitive risks, although the interaction between advancing age at surgery and post-surgical cognitive decline has not been well researched. With many adults with epilepsy living longer, and more older adults developing seizures, the interactive effect of cognitive aging and epilepsy surgery needs to be documented. Methods: The current study evaluated the influence of age at surgery on the cognitive aftermath of temporal lobectomy by examining pre-post surgical cognitive change in a group of patients with intractable epilepsy. Participants were 102 surgical epilepsy patients aged 18-66 who underwent anterior temporal lobectomy and who had participated in comprehensive pre- and post-surgical neuropsychological evaluations. Data was analyzed using both Reliable Change Indices (RCI’s) and Regression-Based z-scores (RBZ’s) as well as multiple regression techniques. The use of multiple analytic techniques provides information about both clinically and statistically significant change. Results: Increasing age was associated with larger-than-expected decrements using RCI and RBZ techniques on the Wisconsin Card Sort and on measures of verbal learning and memory, including the delayed recall of words and stories on the California Verbal Learning Test and the Wechsler Memory Scale-Logical Memory subtests, respectively. Results of regression analyses revealed that age at surgery was a significant predictor of negative change in verbal memory, language, and executive function after left-sided ATL, and of change in PIQ, and verbal and nonverbal memory after right-sided ATL. Conclusions: Older age appears to be a risk factor for greater-than-expected cognitive decline after epilepsy surgery. In particular, declines in cognitive functions normally affected in aging appear to be accelerated by the additional insult of epilepsy surgery. These findings, in addition to the existing literature on post-surgical cognitive decline, should be taken into account when counseling patients about expected effects of surgery on postoperative cognitive function. *This project was funded by the Epilepsy Foundation.