Ictal Electrocorticography Connectivity Analysis Using Time-Varying Phase Transfer Entropy for Seizure Onset Zone...

Effective presurgical localization of the seizure onset zone (SOZ) is critical for achieving seizure control in drug-resistant epilepsy (DRE). Epilepsy is increasingly understood as a network disorder, where disruptions in functional connectivity contribute to seizure initiation and propagation. This study introduces a time-varying phase transfer entropy (PTE) approach to characterize dynamic causal brain interactions in electrocorticography (ECoG) recordings from nine DRE patients with 23 seizures. Findings reveal that SOZ connectivity in high γ (50-250 Hz) band is significantly enhanced at seizure onset (SO) and progressively declines as seizures progress, while non-SOZ (NSOZ) exhibit inhibitory influences on SOZ activity. By integrating time-varying PTE-based connectivity analysis across multiple frequency bands, this study provides insights into seizure propagation mechanisms and contributes to improving SOZ identification for epilepsy surgery planning.Clinical relevance This suggests the time-varying PTE out feature in the high-frequency band may serve as a potential biomarker to identify SOZ.