A 20–150 Hz power rise identified clinician-marked seizure onset zone pairs in 22 SEEG patients, but did not track surgical outcome

We assessed whether a simple ictal-onset feature identifies clinician-marked seizure onset zone (SOZ) bipolar pairs in stereoelectroencephalography (SEEG), replicates across seizures, and relates to surgical outcome. We analyzed 41 seizures from 23 patients and 2,010 within-shaft bipolar pairs in OpenNeuro ds004100 (HUP iEEG); 22 patients had SOZ pairs. The prespecified primary feature, the log10 ratio of 20–150 Hz power in the first 10 s after clinician-marked onset to power 40–10 s before onset, had a median per-patient SOZ AUC of 0.84 (IQR 0.73–0.97; Holm-adjusted p=4.0×10⁻⁴). The paired AUC difference from pre-ictal line length was +0.17, but was not significant (p=0.061). Across 17 patients with two seizures, median AUCs were 0.88 and 0.89 and their correlation was r=0.76; pair rankings were only moderately stable (median Spearman 0.38). No feature tracked surgical outcome (15 seizure-free, 7 not seizure-free). Because clinicians mark the SOZ from ictal recordings, the ictal result partly recovers the labels used to define it and does not establish a better marker of the epileptogenic zone. The analysis included at most two seizures per patient, had small outcome groups, and used a pre-ictal rather than true interictal interval.

seizure onset zone · stereoelectroencephalography · intracranial EEG · ictal onset · high-frequency power · epilepsy · surgical outcome