Authors :
Presenting Author: Jiahao Chen, B.S. – University of Pittsburgh Medical Center
Jorge González-Martínez, MD,PhD – University of Pittsburgh Medical School
Rationale:
Focal-onset epileptic seizures frequently provoke abrupt bradycardic or tachycardic episodes by transiently disrupting the central autonomic network. Such ictal autonomic shifts are the leading mechanistic hypothesis for sudden unexpected death in epilepsy (SUDEP), the most common cause of epilepsy-related mortality. In literature, mesial-temporal and insular cortices have been implicated in autonomic shifts, however, the thalamic pulvinar has only recently been proposed as a possible autonomic hub, and its precise contribution to seizure-related heart-rate (HR) changes remains uncertain. Our study sought to determine whether electrophysiological activity in the pulvinar nucleus correlates with the timing and magnitude of ictal HR perturbations in patients with drug-resistant partial-focal epilepsy.
Methods:
We retrospectively examined stereo-EEG (SEEG) recordings and two-lead ECG tracings from nine patients (sixteen focal-onset seizures) implanted with depth electrodes in the pulvinar, anterior nucleus of the thalamus, insula, amygdala, and hippocampus. Heart-rate onset (HRO) was defined as the first statistically significant outlier in heart rate metrics. SEEG data were segmented into 20-s windows centered on HRO (±10 s). Linear regression assessed the relationship between seizure-onset times in each region of interest and HRO latency, while H² second-order non-linear correlation quantified functional connectivity between the pulvinar and other regions across delta-to-ripple frequency bands, comparing pre-HRO and post-HRO epochs (paired t-tests, p < 0.05).