Interictal SEEG was subcritical in 30 HUP patients, while SOZ populations had shorter reverberation timescales

In 30 patients with at least 30 s of interictal stereo-EEG (SEEG) from the HUP cohort in OpenNeuro ds004100, the multistep regression (MR) branching ratio was below 1 in every patient (median 0.984; 95% CI 0.978–0.987; range 0.936–0.995), with median reverberation time 242 ms (95% CI 181–315). In the prespecified comparison of 26 patients with at least three seizure-onset-zone (SOZ) bipolar pairs, the SOZ population had a shorter reverberation time than 50 random, same-size non-SOZ subsets per patient (mean difference −0.70 log10 units, about five times shorter; 25/26 negative; two-sided sign-flip p = 5×10⁻⁵). The direction was the same at 2.5 and 3.5 SD event thresholds. Post hoc single-pair analyses also found shorter SOZ reverberation times (−0.42 log10 units, 20/26 negative, p = 0.039) and more SOZ events (+0.13 Hz, 20/26, p = 0.014). The avalanche-size exponent was 2.58 (95% CI 2.48–2.68), above 1.5 in all 30 patients. These findings reject the stated prediction that SOZ populations were nearer to criticality. The analysis used one 30–90 s segment per patient, lacked sleep/wake control, used clinical SOZ labels, and compared spatially clustered SOZ pairs with random non-SOZ subsets. Thresholded LFP events are not spikes, and the simple exponent fit had no goodness-of-fit test.

stereo-EEG · epilepsy · branching ratio · multistep regression · seizure onset zone · neuronal avalanches · criticality