Comparison of etomidate and propofol total intravenous anesthesia for electrocorticography monitoring during epileptic focus resection: a retrospective non-inferiority study

Electrocorticography (ECoG) is critical for identifying epileptogenic foci during epilepsy surgery. The choice of anesthetic agent significantly impacts the quality of ECoG signals. This study compared etomidate with propofol total intravenous anesthesia (TIVA) for ECoG monitoring during epileptic focus resection. In this retrospective non-inferiority study, 156 patients with drug-resistant epilepsy undergoing resective surgery were allocated to either etomidate or propofol TIVA groups based on the anesthetic agent used. After propensity score matching, 76 patients in the etomidate group and 75 in the propofol group were analyzed. Primary outcomes included spike frequency and amplitude on ECoG. Secondary outcomes included hemodynamic stability, recovery time, and postoperative complications. A non-inferiority margin of 15% was pre-specified based on clinical relevance, representing an absolute difference in spike frequency (spikes per minute). The primary outcome was defined consistently as spike frequency on ECoG across the study. Etomidate TIVA demonstrated non-inferiority to propofol in spike frequency (difference: 3.6 spikes/min, 95% CI 1.7–5.5), with the lower bound above the predefined margin of − 2.25 spikes/min. Etomidate was associated with significantly higher spike amplitudes (mean difference: 37.5 μV, p = 0.003) and greater intraoperative hemodynamic stability. Propofol demonstrated faster recovery time (17.8 ± 4.2 min vs. 22.5 ± 5.3 min, p < 0.001). No significant differences were observed in postoperative seizure outcomes at 12 months (Engel Class I: 72.0% vs. 69.3%, p = 0.718). Etomidate TIVA is non-inferior to propofol for ECoG monitoring during epileptic focus resection and was associated with higher spike amplitude and greater hemodynamic stability. However, these ECoG enhancements did not translate into improved 12-month seizure outcomes, and their clinical significance should therefore be interpreted cautiously. The choice between these agents should consider the specific clinical context, patient characteristics, and the possibility that enhanced spike activity may not necessarily indicate more accurate localization of the true epileptogenic zone.