CCEP response decreased with distance in three Mayo limbic SEEG patients

We examined single-pulse cortico-cortical evoked potentials (CCEPs) in three of eight patients from OpenNeuro ds004696 (Mayo limbic SEEG). For 1,178 stimulation-site/recording-channel pairs, response z (maximum absolute mean CCEP at 10–50 ms divided by baseline standard deviation) decreased with distance in each patient (Spearman rho = −0.32, −0.42, −0.53; within-patient permutation p < 10−4 for each). The exact two-sided sign-flip p across three patients was 0.25, the minimum possible for this sample. Logistic slopes for response probability (z > 6) were −0.064, −0.055, and −0.075 per mm, close to the 0.070/mm reported for ds005448. Response rates were 0.68–1.00 at 5–15 mm and 0.07–0.12 at 50–200 mm. After distance adjustment, seizure-onset-zone recording contacts had mixed effects: +0.19 log-z (p = 0.010; 12 contacts), −0.33 (p = 0.20; 1 contact), and −0.19 (p = 0.23; 6 contacts). Thus, the SOZ effect was not consistent. The analysis used channel subsets, monopolar signals without re-referencing, and no stimulation-artifact removal beyond a 10 ms blank. Pairs within a patient are not independent, and pair-level permutation p values do not correct for this. The results are limited to three patients and do not establish a population-level effect.

cortico-cortical evoked potentials · CCEP · stereo-EEG · SEEG · electrical stimulation · distance · limbic system · seizure onset zone · OpenNeuro