Interictal SEEG showed higher power and lower line length in clinical seizure-onset contacts, while exponent effects were limited to temporal targets

In 26 patients with SEEG data from the HUP iEEG dataset, features from the first 60 s of one interictal recording per patient separated clinically labeled seizure-onset-zone (SOZ) bipolar pairs from other pairs. Mean within-patient AUC was 0.687 for log power at 1–45 Hz, 0.679 for log power at 65–115 Hz, 0.640 for relative delta power, 0.360 for relative alpha power, and 0.316 for normalized line length; all five results remained significant after Bonferroni correction across eight features. The 20–45 Hz aperiodic exponent had AUC 0.407 (uncorrected p=0.047; corrected p=0.37), so it was not a general SOZ marker. In an uncorrected subgroup analysis, it was flatter in SOZ pairs for temporal-target patients (n=16; AUC 0.30, p=0.0007), but not for extratemporal patients (n=10). Seizure-free and not-seizure-free patients had similar mean AUCs for power features; line length separated SOZ more strongly in seizure-free patients (AUC 0.26 vs 0.40; uncorrected p=0.021). The analyzed cohort was partial: 34 of 39 listed SEEG subjects were processed, and 26 entered the SOZ tests. Results are limited by one 60-s clip per patient, clinical labels, no sleep-stage control, and no anatomical normalization. The temporal exponent finding may reflect normal regional spectral differences and cannot be separated from an epileptogenic effect in this analysis.

SEEG · intracranial EEG · epilepsy · seizure onset zone · spectral power · aperiodic exponent · line length · OpenNeuro