Intraoperative electrocorticography-guided resection of epileptogenic cavernomas: our strategy and literature review.

OBJECTIVE

Intraoperative electrocorticography (ECoG) in the resection of cavernomas associated with drug-resistant epilepsy (DRE) has traditionally been performed with strip/grid electrodes for superficial cortical recording. However, there is no evidence demonstrating a better epileptological outcome for ECoG-guided corticectomy beyond the hemosiderin ring compared with resection limited to the hemosiderin ring. The authors describe a new surgical strategy for intraoperative ECoG recording that combines surface strip ECoG (sECoG) with the intraoperative use of a stereo-electroencephalography (SEEG) electrode to enable recording of deep areas, such as mesial temporal regions, during resection.

METHODS

The authors conducted a retrospective study of a prospectively collected surgical series of cavernoma-related epilepsy (CRE) cases resistant to antiseizure medications treated surgically at their center. They evaluated the seizure outcome after ECoG-guided tailored resection for the treatment of CRE, and they performed multivariate analysis and proportion comparisons to assess which techniques were associated with better seizure outcomes. A systematic literature review of intraoperative ECoG-guided resection for treating CRE was conducted according to PRISMA guidelines.

RESULTS

Twenty-three patients with supratentorial cavernomas associated with DRE who underwent surgery at their center between September 2020 and May 2024 were selected. The postoperative follow-up was conducted at least 12 months after the procedure. Engel class IA outcomes were achieved in 100% of patients who underwent extension of the lesionectomy to areas identified with the SEEG electrode and sECoG. In the multivariate analysis, SEEG electrode application was the only variable statistically associated with better seizure outcomes (Engel class IA). The authors included 12 studies in the systematic review.

CONCLUSIONS

Based on the authors' preliminary experience, the combined SEEG electrode/sECoG technique enables a good seizure outcome for the treatment of CRE. Moreover, compared with sECoG, the use of SEEG electrodes was found to be associated with improved seizure outcomes.