In 90-s SEEG clips, post-spike 70–150 Hz activity fell about 2% and did not significantly separate SOZ pairs

This analysis tested whether interictal spikes were followed by lower 70–150 Hz high-frequency activity (HFA) in bipolar SEEG pairs, and whether the post-spike decrease was larger in clinical seizure-onset-zone (SOZ) pairs after control for spike rate. The analysis used the first 90 s of interictal run 1 for 13 HUP patients from OpenNeuro ds004100. The patients were selected by smaller file size because of network limits, not at random. Only a byte-range prefix of each EDF was read; the source keys, object sizes, ranges, and SHA-256 hashes are recorded in original/provenance/downloads.jsonl. The PSI was mean log HFA from −1.0 to −0.2 s minus mean log HFA from +0.2 to +1.0 s around clean spikes, so positive values indicate suppression. There were 823 detected spikes in 624 bipolar pairs and 432 clean spikes; 56 pairs had at least three clean spikes. Under the planned inclusion rule, only 3 patients were eligible. The primary mean PSI was +0.037 log units (p = 0.25), the SOZ AUC was 0.66 (p = 0.50), and the AUC after spike-rate control was 0.71 (p = 0.25); all Holm-adjusted p values were 0.75. Across 157 pairs with at least one clean spike, mean PSI was +0.023 log units (about 2% lower HFA after spikes), compared with −0.002 at random spike-free times. In the labelled exploratory analysis with at least one clean spike per pair (9 patients), SOZ AUC was 0.62 (p = 0.14); the late-window AUC was 0.64 (uncorrected p = 0.047, Holm p = 0.14). After spike-rate control, AUCs were 0.57–0.59 (p = 0.16–0.42); spike-rate AUC was 0.61. Thus, the decrease was small and was not a reliable SOZ marker in these short clips. The data do not exclude a moderate SOZ effect. Limits include 90 s per patient, 13 patients selected by file size, a simple amplitude detector without visual review, HUP173 sampled at 256 Hz with the HFA band cut at 128 Hz, clinical SOZ labels, and few usable pairs for HUP141, HUP180, and HUP187. A test using full 300-s runs or more runs and more patients is needed.

interictal spikes · SEEG · high-frequency activity · seizure-onset zone · epilepsy · spike rate · OpenNeuro ds004100