Comparative assessment of stereoelectroencephalography and subdural electrodes in invasive epilepsy monitoring: a systematic review and meta-analysis.

Objective: Intracranial electrographic localization of seizure onset zones can guide surgical planning for patients with pharmacoresistant epilepsy. Stereoelectroencephalography (SEEG) and subdural electrode (SDE) monitoring are the two primary intracranial seizure onset zone localization methods. However, the limited availability of data has made it challenging to directly compare the two methods since they have become used contemporaneously. Therefore, the aim of this study was to comprehensively compare the safety and seizure outcome profiles of SEEG and SDE monitoring by performing a double-arm meta-analysis.

Methods: A literature search was conducted using PubMed, Embase, and Cochrane to identify studies comparing SEEG and SDE in patients with pharmacoresistant epilepsy. Only double-arm studies that presented quantitative primary data about seizure outcomes were included. Eligible studies were also assessed for complication rates as a secondary outcome measure. A subgroup analysis was conducted based on age (pediatric only, general, and older cohorts).

Results: Of 233 initially screened unique studies, 15 met inclusion criteria, comprising a total of 1632 patients who underwent SEEG and 1482 patients who underwent SDE monitoring. For all included patients, the rate of favorable seizure outcome was greater for SEEG than for SDE (RR 1.14, 95% CI 1.02-1.27; p = 0.02), and the subgroup analysis based on age demonstrated significantly improved seizure outcomes in the general cohort (RR 1.14, 95% CI 1.00-1.30; p = 0.05) with no significant differences in treatment effect between subgroups (p = 0.92). Regarding safety, SEEG had a lower complication rate than SDE in an analysis of all included patients (RR 0.49, 95% CI 0.37-0.66; p < 0.00001), with the subgroup analysis revealing significantly lower complication rates in pediatric (RR 0.28, 95% CI 0.13-0.61; p = 0.001) and general (RR 0.54, 95% CI 0.40-0.74; p = 0.0001) cohorts, with no significant differences in treatment effect between age subgroups (p = 0.29).

Conclusions: SEEG provides a significantly higher likelihood of favorable seizure outcomes, and a lower complication rate, compared with SDE. However, the efficacy and safety advantages of SEEG were less pronounced in pediatric and older patients, suggesting that age-specific factors could influence the comparative effectiveness of these monitoring techniques. These findings underscore the importance of tailored approaches to intracranial monitoring based on patient demographics and risk profiles.