Ipsilateral thalamic recruitment was not significantly later than the seizure-onset zone or different from matched white matter in focal seizures

We measured the time at which 1-80 Hz line length increases in bipolar SEEG pairs, relative to clinical seizure onset. We used 53 seizures from 19 patients in OpenNeuro ds007445 v1.0.4 and a plan that we hashed before we read the signals. The ipsilateral thalamus increased within 50 s in 63% of the 51 seizures with thalamic pairs (43% by 5 s). The patient-level thalamus-minus-SOZ time was +4.7 s (95% CI -5.5 to +15.2 s; 17 patients; Holm p = 0.40). The thalamus-minus-white-matter time, with the same number of pairs, was -1.7 s (95% CI -13.7 to +10.0 s; Holm p = 0.80). Thresholds z>=3 and z>=6 gave the same conclusion. Secondary result, not corrected: the anterior nucleus increased before the centromedian nucleus (-10.5 s, p = 0.06). The thalamic line-length increase did not have a timing specific to the thalamus. The study cannot exclude a delay of approximately 10 s. The package contains the code, the read checksums, the time courses and the tests.

focal seizures · thalamus · stereo-EEG · line length · recruitment time · seizure onset zone · white matter