Cognitive outcomes following surgical resection in tumoral temporal lobe epilepsy: a scoping review

BACKGROUND AND AIMS: Surgical strategy in tumoral temporal lobe epilepsy (TLE), remains controversial in the literature given the complex balance between seizure cessation and cognitive function post-operatively. Strategies range from lesionectomy to more extensive resections. This review investigates the effects of temporal lobe tumor resection strategies on cognitive function outcomes. METHODS: A comprehensive literature review was conducted using PubMed, Embase, Cochrane, and Web of Science. Search terms encompassed seizure-related conditions (e.g., epilepsy), surgical approaches (e.g., aggressive vs. conservative resection), and neurocognitive outcomes (e.g., neuropsychological function) in the context of temporal lobe tumors. RESULTS: The search identified seven studies examining tumoral TLE resection and outcomes. Three studies within our review reported significant changes in cognitive function, while the remaining four studies did not. Cognitive function appears to be affected by hippocampal resection extent with full hippocampal resection resulting in worse post-operative verbal memory outcomes. Post-operative cognitive function also appears worse in those undergoing lesionectomy or extensive resection of mesial tumors and extensive resection of left temporal lobe tumors. However, there is no clear consensus about the relationship between resection extent and post-operative cognitive function, given the large number of limitations within the current literature. CONCLUSIONS: Across existing literature, there is insufficient evidence to clearly link resection extent and post-operative cognitive outcomes. Given the sparsity of data available, there is a need for more robust, multivariate analyses to evaluate the relationship between resection extent, post-operative cognitive function and the various patient and tumor specific factors that may contribute to outcomes.