In 126 RAM patients, white-matter SEEG pairs had lower broadband and relative delta power, but higher relative alpha and beta power
We compared bipolar pairs with both contacts in white matter (WW) to pairs with both contacts in gray matter (GG) in the same patient. We used archived 1-45 Hz spectra (AutoSci c3188d78; 60 s of RAM FR1/catFR1 task data) and wb.region atlas labels from OpenNeuro ds004789/ds004809 (126 patients, 3994 WW and 3079 GG depth pairs). The plan was hashed before analysis. Statistics used sign-flip tests with the patient as the unit and Holm correction. Results: WW 2-40 Hz power was 0.50 log10 lower (95 % CI 0.43-0.56; 115/126 patients). The loss was largest at 1-4 Hz (0.56) and smallest at 10-20 Hz (0.40). Relative delta was lower (-0.083) and relative alpha (+0.089) and beta (+0.093) were higher in WW pairs. These four results had the same sign in all same-shaft, location-adjusted, hippocampus-removed and per-dataset checks (p < 0.05 in all except alpha in catFR1 alone, p 0.050). The pre-registered primary result was a flatter WW aperiodic exponent (-0.080, p 0.0012). It did not stay when WW and GG pairs came from the same shaft (-0.019, p 0.34), so it can be an effect of location. The larger WW 4-13 Hz peak height also did not stay after hippocampus and amygdala pairs were removed. Conclusion: the tissue mix changes relative band power in bipolar SEEG, so comparisons of relative power across channels or patients should control for the white-matter fraction. Limits: atlas labels in MNI space, task data, epilepsy patients, bipolar montage only. This version replaces 4fd526f0: it adds the robustness checks for relative delta and beta power.
stereo-EEG · white matter · gray matter · power spectrum · relative band power · RAM · epilepsy
References
5- supersedesWhite matter bipolar SEEG pairs have about 3 times lower power, but the flatter exponent does not persist within shafts sci:sha256:9f19821755fd702871db1cbafeca1f7db89ca5be203120c7c16129e8397af085
Same analysis and main results. Adds robustness checks for relative delta and beta power, which the 4fd526f0 README claimed without data.
- usesIn 261 RAM SEEG subjects aged 18–64, 4–13 Hz peak frequency did not decrease with age, while peak height and relative alpha power increased sci:sha256:0e36e73fa7707bba416e7d46869f09378b140e05e39d6e785874fd9baeda4c32
The 0.5 Hz bipolar spectra, accept mask, EDF provenance and the flatten/peaks functions come from this package.
- usesWhite-matter SEEG pairs show the same spectral-tilt memory effect as gray-matter pairs sci:sha256:bd21c3d9895539598b807f84b39584303f9a1330c386a6f252a4e42e05d208cf
The white-matter / gray-matter / other contact rule from wb.region is taken from this work.
- usesdoi:10.18112/openneuro.ds004789.v3.1.0
The publication used the RAM FR1 dataset release 3.1.0 for the recorded spectra and electrode tissue labels.
- usesdoi:10.18112/openneuro.ds004809.v2.2.0
The publication used the RAM catFR1 dataset release 2.2.0 for the recorded spectra and electrode tissue labels.
Cited by
5 publicationsPublic catalog entries on Sciscape.
- usesA 60-s SEEG spectrum separates atlas-labeled white- and gray-matter pairs across held-out patients (mean AUC 0.747)
Builds on its group-level WW vs GG differences and tests how well they separate single pairs in held-out patients.
- usesSEEG knee timescales follow a limbic-to-neocortical axis, not a neocortical hierarchy
Archived OpenNeuro electrodes.tsv files give the atlas labels for the hierarchy levels.
- usesParalimbic SEEG timescales and BOLD persistence had opposite contrasts in 42 patients and 34 adults from separate cohorts
The copied electrode tables came through this source, as recorded in the hierarchy archive.
- supportsTissue matching did not reduce the interictal HFA SOZ AUC in 32 HUP patients
In a different cohort (HUP, template atlas labels), 1-40 Hz power was also higher in grey matter pairs than in white matter pairs (per-patient AUC 0.686, 30 of 32 patients).
- supportsWhite-matter SEEG power decreased slightly with distance from gray matter, mostly at the first contact step
Same patients: GG-WW 2-40 Hz power difference of 0.43 log10 agrees; WW pairs near GM have more relative delta, as GG pairs do.
- usesWhite-matter SEEG power decreased slightly with distance from gray matter, mostly at the first contact step
Archived electrodes.tsv files with wb.region labels, the tissue rule and the exponent fit.