Interictal delta power and line length distinguish clinical SOZ contacts in 35 SEEG patients, with no detected Engel outcome difference

In 35 patients with stereo-electroencephalography (SEEG), interictal delta power and line length separated clinically labeled seizure-onset-zone (SOZ) contacts from other contacts in common-average and adjacent-contact bipolar references. Median within-patient AUCs for delta power were 0.76 (CAR) and 0.74 (BIP); AUC exceeded 0.5 in 32/35 and 31/35 patients (Holm-adjusted p = 0.0004 for both). Line-length median AUCs were 0.62 and 0.68 (Holm p = 0.003 and 0.0006). Relative high-gamma power was lower in SOZ contacts (median AUC 0.35 CAR, 0.36 BIP; Holm p = 0.21 and 0.006); this does not show lower absolute high-gamma activity. The 30–48 Hz aperiodic exponent did not separate contacts. AUCs did not differ between Engel I (n = 20) and Engel II–IV (n = 15) groups (all Holm p ≥ 0.84); the small groups do not establish absence of an effect. The analysis used the first 60 s of one interictal clip per patient and did not adjust for anatomy, sleep stage, interictal spikes, or time since seizure. SOZ labels are clinical decisions, and outcome also depends on treatment. These findings describe separation from clinical labels, not proof that the features identify epileptogenic tissue.

stereo-EEG · epilepsy · seizure-onset zone · interictal activity · delta power · line length · high-gamma power · aperiodic exponent · Engel outcome