Do Larger Resections Cut It? Relating Temporal Lobe Epilepsy Surgery and Seizure Outcome

Anterior temporal lobe resection (ATLR) results in seizure freedom in half of individuals with drug-resistant temporal lobe epilepsy (TLE). Some investigators have suggested that larger resections lead to greater chance of seizure freedom, while others report no relationship. In this study, we examine the relationship between resection size and seizure freedom through (i) total volume analysis and (ii) a mass univariate regional approach.Patient demographics and resection volumes were collected for 283 patients who underwent subsequent ATLR, and seizure freedom was measured after 12 months. Additionally, the percentage resection of each Desikan-Kiliany parcellated region was calculated. We computed the AUC to measure effect sizes and used Wilcoxon ranksum tests to assess significance.Total resection volumes were larger in males than females, and larger in right than left ATLR. However, when scaled to percentage of brain tissue resected, only the hemisphere difference remained. There was no significant association of total or regional resection volume with post-operative seizure freedom.Larger resections in males are due to their larger total brain volumes. Smaller left-sided resections reflect the more conservative surgical approach in the language dominant hemisphere. Within the normal ranges of a typical ATLR, larger resection volumes do not increase chance of seizure-freedom. Future studies should investigate the details of the resection of gray matter, such as piriform cortex, and white matter tracts that can form epileptogenic networks.