Onset-pair activity rose before the clinical onset mark in 143 HUP SEEG seizures from 37 patients

We used archived per-second SEEG features (log 20-100 Hz power and line length, bipolar pairs) of 143 seizures from 37 HUP patients (OpenNeuro ds004100). For each seizure, the onset pairs were the top 10% of pairs by z in the first 10 s after the clinical onset mark. The primary statistic (fixed before the outcome) was D = (onset-pair minus other-pair z in [-10, 0) s) minus (the same in [-25, -15) s). D was positive in 31 of 37 patients (HF mean 1.10 z, 95% CI 0.43-2.14, sign-flip p = 1e-5). Line length gave the same result. Clinical SOZ pairs gave a smaller positive D (0.37 z, p = 0.005). The excess rose slowly from -25 s and became steeper in the last 6-10 s. A run of 3 s with onset-pair z >= 3 started before the mark in 19% of seizures (median 11 s before the mark). In most seizures, the first run started at or after the mark (median 0 s). Limits: the onset pairs come from the same seizure, the excess is already present at -25 to -15 s, the sham segment is shorter than the test segment, the definition of the mark is not known, and the data come from one center.

stereo-EEG · seizure onset · epilepsy · intracranial EEG · high-frequency power · line length · seizure detection