Epilepsy surgery in children with operculo-insular epilepsy: Results of a large unicentric cohort

Objective Epilepsy surgery in the operculo-insular cortex is challenging due to the difficult delineation of the epileptogenic zone and the high risk of post-operative deficits following resections in this region. Methods Pre- and post-surgical data from 30 pediatric patients who underwent opercular-insular cortex surgery at Motol Epilepsy Center Prague from 2010 to 2022 were analyzed. Results Focal cortical dysplasia (FCD, n = 15) was the predominant cause of epilepsy in the patients studied, followed by epilepsy-associated tumors (n = 5) and tuberous sclerosis complex (n = 2). In eight patients where FCD was the most likely etiology, histology was negative. The epileptogenic zone was in the dominant hemisphere in 16 patients. Variability in seizure semiology and electrophysiological findings necessitated multimodal imaging and advanced post-processing for precise epileptogenic zone localization. Stereoelectroencephalography (SEEG) monitoring was used in 23 patients. The use of oblique electrodes as guides during resection proved beneficial for the neurosurgeon. At the two-year follow-up, 23 patients were seizure-free (ILAE Classification of Outcome 1), and seven experienced a seizure frequency reduction of > 50% (ILAE 4). Nineteen remained seizure-free following the definitive outcome assessment (2–13 years post-surgery). Five from 15 patients operated in posterior insula experienced pyramidal tract ischemia, leading to permanent mild hemiparesis in three patients and moderate hemiparesis in one patient. One patient experienced unexpected pontine ischemia 9 days post-surgery, leading to permanent spastic hemiparesis. Five other patients experienced transient deficits. Significance Despite diagnostic and surgical challenges, epilepsy surgery in the opercular-insular cortex can lead to excellent patient outcomes. A comprehensive diagnostic approach is crucial for surgical success. For surgeries in the posterior insula, ischemia in the pyramidal tract and subsequent hemiparesis of varying severity should be anticipated. However, in pediatric patients, there is a great chance for significant recovery with proper rehabilitation. Key points ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by the Ministry of Health of the Czech Republic NU23-08-00528; Ministry of Health of the Czech Republic, research project 00064203 Motol University Hospital; Charles University Grant Agency (GAUK), research project 666320. Radek Janca was supported by ERDF-Project Brain Dynamics, No. CZ.02.01.01/00/22_008/0004643. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the institutional Ethical committee of Motol University Hospital (2022/06/15 - EK - 602.24/22). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Majority of data produced in the present work are contained in the manuscript and supplementary materials, potentially de-anonymizing information is available from the authors upon request