Responders to Vagus Nerve Stimulation in Refractory Epilepsy Have Weaker Causal Pathways: Interictal Scalp EEG Network Analysis
Abstract number :
3.169
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2019
Submission ID :
2422067
Source :
www.aesnet.org
Presentation date :
12/9/2019 1:55:12 PM
Published date :
Nov 25, 2019, 12:14 PM
Authors :
Chae Y. Lee, Samsung Medical Center; Dae-Won Seo, Samsung Medical Center; Eun Yeon Joo, Samsung Medical Center; Seung Bong Hong, Samsung Medical Center; Young-Min Shon, Samsung Medical Center
Rationale: The underlying mechanism for antiepileptic effect of vagus nerve stimulation (VNS) has never been clearly documented. The present study aims to identify the impact of VNS-on/off state on their effective brain connectivity using source decomposition and effective connectivity tools. Methods: We estimated the effective brain connectivity between scalp EEG signals using partial directed coherence (PDC) in 14 patients with chronic VNS therapy. Effective brain networks of estimated changes between ON and OFF phases and between responder (R) and non-responder (NR) patients. Results: We found that R have a weaker causal efferent pathways (almost all frequency band) than NR (p < 0.01). In addition, ON periods were characterized by weaker causal efferent pathways at midline fronto-central areas in comparison with OFF periods. Especially, R had significantly stronger afferent pathways towards their irritative zones (areas of interictal or ictal onset zones), especially in theta, alpha & lower beta frequency bands (p < 0.05). Conclusions: VNS responders have thus a lower effective connectivity at the midline or central propagation areas and stronger afferent connectivity at their irritable zones than non-responders. Estimating changes of effective connectivity is thus a promising tool for predicting response to VNS. Funding: No funding
Neurophysiology