Epilepsy Surgery Triggers Widespread Brain Network Changes With Mixed Effects
Epilepsy surgery, particularly for temporal lobe epilepsy (TLE), causes extensive structural and functional changes in the brain that go far beyond the resected tissue, according to a study published in Brain.
Brain changes can include degeneration, recovery, or reorganization across distant regions, reshaping entire brain networks. While the goal of surgery is seizure control by removing the seizure onset zone, the procedure often disrupts both diseased and healthy pathways.
Research has shown that such network-level effects can sometimes correlate with improved seizure outcomes but may also result in neuropsychological deficits, especially in memory, language, and vision. Studies using magnetic resonance imaging (MRI), diffusion imaging, positron emission tomography (PET), and functional MRI have documented bilateral cortical thinning, reduced metabolism, altered connectivity, and changes in white matter integrity even in areas remote from the surgical site. Importantly, greater reorganization and loss of abnormal connectivity have been linked to seizure freedom, suggesting that both direct damage to epileptic hubs and indirect remodeling may play therapeutic roles.
Despite the widespread changes, surgery can promote recovery in parts of the brain relieved from epileptic activity, and this potential is particularly strong in children due to heightened neuroplasticity. Still, predicting which patients will benefit most remains a challenge. Post-surgical brain states vary by individual factors such as resection size, preexisting network health, and age at surgery. To better predict surgical outcomes, researchers are exploring models that simulate the effects of surgery using preoperative imaging. However, analyzing post-surgical data presents technical hurdles, including brain shifts and distorted tractography, which complicate comparisons. Moving forward, larger, multicenter studies collecting multimodal, longitudinal data are needed to refine predictive tools and personalize epilepsy surgery.
“Although there are challenges to collecting and processing post-surgical imaging, the potential for uncovering the mechanistic underpinnings of epilepsy surgery and developing prognostic biomarkers highlight the importance of these investigations,” concluded the study authors.
Reference
Sainburg LE, Englot DJ, Morgan VL. The impact of resective epilepsy surgery on the brain network: evidence from post-surgical imaging. Brain. 2025;148(6):1866-1875. doi:10.1093/brain/awaf026
