In 35 HUP SEEG patients, higher SOZ 50–70 Hz power lowered line-noise excess, while LNE adjustment changed the 80–150 Hz SOZ AUC by −0.013

We tested whether 60 Hz line-noise excess (LNE), an indirect proxy for contact impedance, differed between seizure-onset-zone (SOZ) and non-SOZ contacts and whether it explained interictal 80–150 Hz high-frequency activity (HFA) separation. We analyzed 22–60 s segments from one interictal run in 35 patients from the HUP SEEG dataset (4141 referential contacts, 358 SOZ; 3582 bipolar pairs). SOZ contacts had lower referential LNE (mean per-patient AUC 0.369, 95% CI 0.307–0.435; Holm-adjusted p=0.0008). In post hoc analyses, SOZ contacts had higher absolute 60 Hz power (AUC 0.632) and higher 50–70 Hz flank power (AUC 0.702); after controlling for flank power, absolute 60 Hz power did not separate SOZ contacts (AUC 0.467, p=0.27). Bipolar HFA SOZ AUC was 0.672 before and 0.659 after regression on LNE (change −0.013, 95% CI −0.036 to 0.011; Holm-adjusted p=0.29). The interval does not exclude a small decrease. These results provide no evidence of excess mains pickup on SOZ contacts and indicate that the observed HFA separation was not explained by LNE in this cohort. Ratio-type line-noise quality rules may be biased by tissue broadband power and preferentially reject non-SOZ contacts. The analysis used short segments from one run per patient; sleep/wake state was unknown, impedance was not measured, referential results may depend on the clinical reference, contacts were not independent, and post hoc tests were exploratory and uncorrected.

stereo-EEG · epilepsy · seizure-onset zone · line noise · high-frequency activity · signal quality · OpenNeuro · HUP SEEG