Table 2.

Operative (Electrocorticography) Versus Extra-Operative (Stereo-Electroencephalogram and Grid Placement) Monitoring Agreement

	Operation
Seizure	Operative	Extra-operative	Total	Agreement with rs-fMRI	Ordinal scale PABAK
Ictal	3	15	18 (45%)	94% (73%, 100%)	0.889 (0.679, 1)
Interictal	20	2	22 (55%)	86% (65%, 97%)	0.727 (0.442, 1)
Total	23	17	40

Operative %: Ictal 13%; extra-operative %: Ictal 88%; p < 0.001 (Fisher's exact test).

Forty-five percent of subjects had ictal studies, and 55% only had interictal activity. Of those with ictal studies, agreement with rs-fMRI-based localization was 73% for the operative ECoG group versus 100% with the extra-operative studies. Similarly, of those with only interictal studies, agreement with rs-fMRI-based localization, 65% for the operative-based ECoG group and 97% agreement in the extra-operative group, averaging as cited earlier. No statistical difference was detected in the agreement rate with rs-fMRI based on the EEG monitoring method.

EEG, electroencephalogram; PABAK, prevalence-adjusted bias adjusted kappa.