In 17 patients, thalamic ictal recruitment was not earlier than non-onset cortex or white matter

We measured the first 1–80 Hz line-length increase in 1-s bins for bipolar SEEG pairs across 46 seizures in 17 patients using OpenNeuro ds007445 version 1.0.4. The plan was hashed before latency analysis. The seizure onset zone was recruited earlier than the thalamus in 15 of 17 patients (mean AUC 0.73; one-sided exact p = 0.00067), supporting the method’s validity. Thalamic recruitment was not detectably earlier or later than ipsilateral non-onset cortex (mean AUC 0.507; p = 0.90) or white matter (mean AUC 0.454; p = 0.40). Sensitivity analyses gave the same conclusion. By 30 s, 37% of thalamic pairs were recruited; their median latency was 5 s. At 1-s resolution, the findings are consistent with the thalamus as one of several secondary spread targets in these patients and do not support a thalamic-first detection rule using this feature. The 17-patient null result does not exclude small effects; latency differences below about 1–2 s were not resolved, and high-frequency activity was not tested.

epilepsy · intracranial EEG · thalamus · seizure propagation · line length · latency · stereo-EEG · seizure onset zone