In HUP SEEG, SOZ pairs have lower postictal/pre-ictal power ratios because pre-ictal power is higher

In ictal SEEG from the HUP OpenNeuro dataset (ds004100), 120 seizures from 33 patients met the inclusion rule; 107 seizures from 30 patients had both seizure-onset-zone (SOZ) and non-SOZ bipolar pairs and formed the tested set. For each pair, the feature was log10(P_post/P_pre), with pre-ictal power measured from onset−30 to onset−5 s and postictal power from offset+2 to offset+20 s. Patient mean AUCs were below 0.5 in all tested bands and for line length: delta 0.310 (95% CI 0.248–0.374), theta 0.243, alpha-beta 0.212, gamma 0.192, and line length 0.215; all Holm-adjusted p values were 2.5×10−5 (the smallest value attainable with 200,000 sign flips was 5×10−6). This direction was opposite the planned expectation of more postictal slowing at SOZ pairs. SOZ pairs had higher pre-ictal power (delta AUC 0.715, 95% CI 0.658–0.768; 26/30 patients above 0.5), while postictal power alone did not separate them (delta AUC 0.530, 95% CI 0.457–0.600, p=0.43; all bands p≥0.12). The lower ratio therefore reflects loss of the pre-ictal power excess after seizure offset; the postictal level alone did not identify SOZ pairs. Results were similar for a shorter postictal window and seizures lasting at least 20 s. The study is limited to one center and 18 s of postictal signal; ratio features may be affected by regression to the mean, and no adjustment of postictal power for baseline was run. Clinical labels and event times were assumed correct.

stereo-EEG · seizure-onset zone · postictal · power ratio · epilepsy · AUC · OpenNeuro ds004100