Corpus callosotomy for intractable epilepsy in the pediatric population: value of intraoperative neurophysiological monitoring

Abstract

Background: Intraoperative neuromonitoring (IONM) is utilized in many neurosurgical procedures. It is often employed when operating in close proximity to eloquent regions as it can delineate such areas from the targeted resection. IONM can additionally provide surgeon assurance and confidence in chosen intraoperative maneuvers. However, there is no clear consensus regarding whether it provides significant value in pediatric corpus callosotomy. This study reviews the current literature to evaluate intraoperative utility, prognostic value, and medicolegal considerations of IONM in pediatric corpus callosotomy.

Methods: An extensive literature review was performed through PubMed, OVID Medline, SCOPUS, and Embase. Reference lists were manually screened to identify additional applicable articles. Studies were evaluated qualitatively for inclusion and reported descriptively.

Results: The search strategy yielded 1523 articles. Following duplicate removal, initial screening, and full-text review, 8 were included. Both disruption of bisynchronous epileptiform discharges (EDs) and lateralization of previously generalized EDs have been proposed as having a prognostic value in callosotomy. No significant correlation between intraoperative ED changes and seizure outcomes has been found in the studies evaluated here. Guidance of posterior dissection extent has also been suggested to be of intraoperative utility in callosotomy. Given that the majority of corpus callosotomies in the pediatric population are complete as opposed to an anterior two-thirds technique, the overall utility in dissection guidance is low.

Conclusion: IONM has not been found to provide significant prognostic value nor strongly contribute to improving surgical outcomes during corpus callosotomies for pediatric patients with intractable epilepsy. Medicolegal considerations across the field of neurosurgery have grown in recent years; the majority of litigation perspectives are isolated to spine surgery, with IONM functioning more for documentation purposes in pediatric corpus callosotomy. The use of IONM during pediatric corpus callosotomy remains the surgeon's preference as it has not been defined as the standard of care.

Keywords: Corpus callosotomy; Intractable epilepsy; Intraoperative neuromonitoring; Pediatric neurosurgery.