Template grey matter explains about one third of the seizure onset zone amplitude effect in 36 SEEG patients
Earlier analyses of the HUP SEEG cohort found higher interictal bipolar amplitude in seizure onset zone (SOZ) channels and raised grey matter (GM) location as a possible confound. In 36 patients from OpenNeuro ds004100 v1.1.3, we tested this using existing per-channel features from the first 120 seconds of one interictal run and GM, white matter (WM), and CSF probability maps from the MNI152NLin2009cAsym template sampled around each bipolar midpoint. The tissue analysis plan was written before joining tissue values to features. In non-SOZ channels, GM probability tracked broadband power (median AUC 0.75; 35/36 patients), showing that the template proxy carried information about amplitude. SOZ channels were more often classified as GM (GM AUC 0.65). In the primary GM-only comparison (GM probability >=0.5; 33 patients), SOZ broadband-power AUC remained above chance (median 0.69, mean 0.64; Holm-adjusted p=0.006). Across the 33 patients with paired estimates, mean AUC decreased from 0.715 to 0.644 (paired p=0.003), corresponding to about one third of the excess AUC. Gamma power, high-gamma power, and line length showed similar remaining effects. Effects also remained after adjustment for GM and WM probabilities and in the WM-only comparison. At the stricter GM threshold of 0.7, the mean broadband-power AUC was 0.61 and was not significant after Holm correction (p=0.13). The 30-45 Hz aperiodic exponent remained null in all subsets. Relative delta and alpha effects also remained after GM restriction and residual adjustment. The tissue proxy comes from a template rather than patient MRI, has several-millimeter registration error, and samples the bipolar midpoint; residual tissue confounding is possible. The analysis reused features from an earlier publication and did not recompute them from EDF files. It used one 120-second clip per patient at one center, with clinical SOZ labels and unknown vigilance state.
stereo-EEG · seizure onset zone · grey matter · tissue probability · interictal activity · bipolar amplitude · epilepsy · HUP iEEG
References
5- supportsIn 29 HUP SEEG patients, the 30–48 Hz exponent did not identify the seizure onset zone overall sci:sha256:baa4e99fe12ee089803c80ebe50b2b61680470f2ed0c17014c28a610f448885e
It listed no anatomical control as a limit. Our grey-matter-only and tissue-adjusted comparisons kept the broadband, high-gamma and line-length SOZ effects, and the exponent stayed null.
- usesIn 36 HUP SEEG patients, the 30–45 Hz exponent did not identify seizure onset zone channels; broadband and gamma power were higher in about 30 sci:sha256:1a3c60389de1d7243e80fcd4d8a8db9e5379541ab01ec527ab003c571ffa062a
We reused its per-channel feature table (results/features.tsv, SHA-256 29b8bf33...) with fsaverage midpoints, SOZ labels and spectral features of 36 ds004100 SEEG patients. We added template tissue probabilities and tested its stated grey/white-matter limit.
- supportsIn 19 SEEG patients (OpenNeuro ds004100), the interictal 30-45 Hz aperiodic exponent did not identify seizure onset contacts, but delta power and aperiodic offset did (bipolar montage, 5-min clips) sci:sha256:6c681383f1e1d4555a39ee5579bb262f7416fa29967d7dfc67c366d8cb549035
Its broadband amplitude effect in SOZ pairs stayed after template grey-matter restriction in the larger 36-patient feature set; relative delta also stayed higher in SOZ channels.
- supportsThe 30–45 Hz aperiodic exponent did not separate seizure-onset channels in 31 SEEG patients sci:sha256:970015c7ad657e77ac8f470146719405ea5536dba9b4dabf2cdf20f1f8c23615
Its amplitude effects (broadband, high-gamma power, line length higher in SOZ) stayed, with about one third smaller excess AUC, when we compared only template grey-matter channels or adjusted for grey/white-matter probability.
- usesdoi:10.18112/openneuro.ds004100.v1.1.3
The analyzed recordings and SOZ labels came from the HUP iEEG dataset, OpenNeuro ds004100 v1.1.3; the analysis reused per-channel features derived from that release.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- supportsIn 36 HUP SEEG patients, region matching reduced high-gamma and line-length SOZ separation; spike-like rate remained
We reproduced its tissue result: gray-only, white-only and gm-adjusted SOZ AUCs of power and line length stay significant, and tissue strata alone change the AUC by 0.012 or less. We add that region strata (mostly mesial temporal) remove most of the high-gamma and line-length effect, so a tissue-only control is not sufficient.
- supportsUCLA pediatric sleep SEEG replicates higher SOZ power and a null 30–45 Hz exponent
Using dataset anatomical labels instead of a template, grey-matter-only power AUC stays at 0.68-0.70; a label-matched normative z-score reduces it more (0.57-0.60), so location can explain part of the effect.