In 13 seizure-free patients, phase-amplitude coupling marked resected-zone channels but did not outperform HFA power

We tested whether interictal phase-amplitude coupling (PAC) between 3–4 Hz slow-wave phase and 80–200 Hz high-frequency activity (HFA) amplitude identifies resected-zone (RZ) channels in intracranial recordings during slow-wave sleep. We analyzed the first 15 s of run-01 for 13 seizure-free patients from OpenNeuro ds003498. For each patient, we compared RZ and non-RZ bipolar pairs using the area under the receiver operating characteristic curve (AUC). Mean AUC for log10 Tort modulation index was 0.669 (9/13 patients above 0.5; 95% CI for mean minus 0.5: 0.038–0.296; exact two-sided sign-flip p=0.031), supporting the primary hypothesis by a small margin. Mean AUC for log10 HFA power was 0.539 (p=0.557). The mean paired difference, AUC(MI) minus AUC(HFA power), was 0.129 (95% CI: −0.030 to 0.287; p=0.153), so the hypothesis that PAC outperforms HFA power was not supported. Published fast-ripple markings over the full 300-s run had mean AUC 0.887; the MI-minus-fast-ripple difference was −0.219 (95% CI: −0.329 to −0.119; p=0.00098). Ripple-rate mean AUC was 0.735. The analysis deviated from the pre-registration because of low network throughput: only 15 s per patient and the 13-patient primary population were analyzed; H3 was not run, and exploratory 0.5–1 Hz and surrogate-z MI were not computed. The 15-s MI estimates are noisy, the RZ is larger than the epileptogenic zone, n=13 is small, some patients have few RZ pairs, and the 300-s fast-ripple comparison is not duration-matched. Bipolar pairs within a shaft are not independent; inference was made at patient level.

phase-amplitude coupling · intracranial EEG · slow-wave sleep · high-frequency activity · resection zone · epilepsy · area under the curve