Does electrocorticographic guidance improve seizure outcomes following cavernoma resection?

Cerebral cavernous malformations (CCMs) are vascular anomalies frequently associated with drug-resistant epilepsy. Surgical resection is a well-established treatment; however, the optimal strategy to achieve long-term seizure freedom (SF) remains unclear. Intraoperative electrocorticography (ECoG) may enhance seizure outcome by guiding resection extent, yet comparative evidence is limited. To evaluate the efficacy of ECoG-guided resection in patients with CCMs, a single-center comparative retrospective cohort analysis and a meta-analysis were performed.

We analyzed 67 adult patients with CCMs who underwent resective surgery with or without ECoG guidance at our institution. The primary outcome of interest was SF. Statistical analysis included univariate analysis, Kaplan-Meier and receiver operating characteristic curves, and uni- and multivariate logistic regression. Additionally, we searched databases to identify studies reporting SF outcomes in patients with CCM-related epilepsy who underwent ECoG-guided surgery. A random-effects model was used to calculate pooled odds ratios (ORs) with 95% confidence intervals (CIs).

Seventeen patients underwent ECoG-tailored resection, and 50 underwent standard microsurgical lesionectomy (non-ECoG). SF rates were higher in the ECoG group at 24-, 30-, and 36-month follow-up (p < .05), although the ECoG group also displayed greater resection volumes (p < .01). After excluding temporal lobectomies, improved seizure outcomes remained significant only in extratemporal ECoG-guided lesionectomies (p < .05). On univariate analysis, ECoG use and postsurgical antiseizure medication were significant predictors of SF. Meta-analysis of seven studies, including our cohort, comprised 241 patients (130 ECoG, and 111 non-ECoG) and demonstrated better seizure outcomes with ECoG-guided resection compared to lesionectomy alone (OR = 6.01, 95% CI = 3.03-11.92, p < .001).

ECoG-guided resection is associated with better long-term SF in patients with CCM-related epilepsy. Our evidence shows that ECoG may be a useful adjunct in cases of CCM-related epilepsy surgery, particularly in extratemporal lesions.