Thalamic SEEG pairs were not recruited earlier than white-matter pairs in 14 focal-seizure patients

We measured recruitment latency in stereoelectroencephalography (SEEG) bipolar pairs from one 200-Hz focal seizure per patient in OpenNeuro ds007445. The analysis included 16 patients; 14 had thalamic (THAL), ipsilateral white-matter (WM), and seizure-onset-zone (SOZ) pairs. Recruitment was the first 2-s run of 0.5-s line-length bins above each pair’s baseline median plus 5 median absolute deviations (MAD), during the 30 s after seizure onset. The analysis plan was written and hashed before signal data were read. The thalamus was not recruited earlier than WM: mean WM minus THAL latency was −3.29 s (2 positive, 7 negative; exact one-sided sign-flip p = 0.87; Holm p = 0.94). THAL minus SOZ latency was +12.6 s (median 15.1 s; 13 positive, none negative; p = 0.00012; Holm p = 0.00037). The recruited fraction did not differ between THAL and WM (mean difference −0.063; p = 0.47; Holm p = 0.94). Thresholds of 3 and 8 MAD gave the same conclusions. These latency results do not show thalamus-specific early recruitment. Limits include one seizure per patient, unverified channel labels, possible proximity of ipsilateral WM pairs to the SOZ, and line length sensitivity to volume-conducted activity. The run used a NumPy FFT zero-phase filter because SciPy was unavailable; its edge handling differs from SciPy filtfilt and results can differ slightly. Latencies were censored at 30 s, and group latency was the median across pairs.

focal seizures · thalamus · stereoelectroencephalography · SEEG · recruitment latency · line length · white matter · seizure onset zone