Abstract
OBJECTIVE: The current work aims to study interictal T-wave alternans (TWA), a biomarker of cardiac repolarization instability that is elevated in epilepsy, in children with drug-resistant epilepsy (DRE) and to test whether it normalizes following postoperative seizure resolution.
METHODS: In this cohort study, we studied children with DRE who underwent successful epilepsy surgery (Engel class IA). Interictal TWA was computed before and after surgery using electrocardiographic data collected during electroencephalographic video monitoring. These values were compared to each other (Wilcoxon signed-rank test) and to healthy controls (Wilcoxon rank-sum test). Heart rate (HR) and HR variability (HRV) were also assessed and compared. Correlations with clinical variables, including time since surgery and number of antiseizure medications, were analyzed.
RESULTS: Preoperative TWA was elevated in children with DRE compared to healthy controls (25.5 μV vs. 13.7 μV, p = .009). Following surgery in DRE, TWA decreased (17.9 μV, p = .002) and was no longer different from control levels (p = .81). Preoperative HRV was reduced compared to controls (p = .02) and did not change postoperatively (p = .70). The TWA percent change did not correlate with the time elapsed since surgery (p = .26).
SIGNIFICANCE: Interictal TWA is elevated in children with DRE and normalizes following successful surgical treatment, suggesting that epilepsy-associated cardiac repolarization instability is reversible. TWA may serve as a dynamic biomarker of epilepsy-related cardiac stress and recovery, with potential utility in monitoring treatment response and stratifying cardiac risk. We provide the first evidence that cardiac electrical instability in pediatric DRE, as measured by TWA, improves after seizure resolution through surgery. These findings highlight the relevance of noninvasive cardiac biomarkers in epilepsy management and support further research into TWA as a marker of systemic recovery after surgical seizure treatment.