Surgical Aspects of Opercular Epilepsies

Summary:

Operculoinsular epilepsy presents diagnostic and surgical challenges due to the complex anatomy of the opercula, the underlying insula, and their intimate relationships with major vascular and subcortical white matter tracts. Comprehensive evaluation relies on detailed seizure semiology, high-resolution structural and functional neuroimaging, and invasive monitoring (namely, stereoelectroencephalography) to distinguish opercular from insular seizure onset and identify suitable surgical candidates. Advances in invasive recording capabilities, intraoperative mapping, microneurosurgical techniques, and laser ablative technologies have expanded access to epileptogenic networks in this region, improving the safety and precision of operative approaches for the treatment of epilepsy. This review outlines the relevant surgical anatomy of the frontal, parietal, and temporal opercula and deeply-situated insula, emphasizing the need for meticulous preoperative planning and accurate intraoperative recognition of anatomical landmarks. We describe resective strategies (including transsylvian and transopercular approaches), tailored to epileptogenic localization while minimizing risk to critical vasculature and eloquent cortex. Intraoperative electrocorticography, functional mapping, and neurophysiological monitoring further refine surgical margins and help mitigate postoperative deficits. We also highlight stereotactic laser interstitial thermal therapy as a minimally invasive alternative for well-defined epileptogenic zones, particularly in the dominant hemisphere or deep opercular tissue, offering reduced morbidity and shorter hospitalization. Reported seizure-freedom rates following resective operculoinsular epilepsy surgery are 60% to 70%, and around 50% with laser interstitial thermal therapy, with relatively safe complication profiles. Ultimately, a thorough understanding of anatomy, careful patient selection, and judicious use of adjunctive mapping technologies are essential to achieving optimal seizure outcomes in the safe surgical management of operculoinsular epilepsy.