Dynamics of Thalamo-cortical Connectivity During Seizures in MTLE
Abstract number :
2.178
Submission category :
3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year :
2024
Submission ID :
1245
Source :
www.aesnet.org
Presentation date :
12/8/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Jude Savarraj, PhD – University of Texas Health Science Center at Houston
Aila Teimouri, BS – Rice University
Jasper Wang, BS – Rice University
Nitin Tandon, MD – University of Texas Health Science Center, School of Public Health, Houston, Texas, USA.
Rationale: The thalamus plays a crucial role in modulating cortical sites during transitions between seizure states. The precise role of thalamic engagement with cortical sites during seizure states remains unclear. This study aims to investigate these dynamics.
Methods: We recorded sEEG data from medial temporal lobe epilepsy (MTLE) patients (n=6) with at least one electrode implanted in the thalamus. To analyze thalamo-cortical dynamics during MTLE seizures, we constructed functional connectivity networks by calculating the Phase Locking Value (PLV) across various frequency bands (δ, θ, α, and β) and the networks were segmented into pre-ictal and ictal periods. To compute the importance of the thalamus in the MTLE network during seizures, we computed its nodal network metrics, including degree centrality (DC) and eigenvector centrality (EC), for each period. We report the percentage change of metrics in the ictal compared to the pre-ictal state.
Results: The thalamo-cortical connectivity in the 𝜃 and β bands were the most sensitive to seizure state transitions, each showing an average absolute percent change of approximately 10.15% and 11.9 % respectively in the ictal state compared to pre-ictal state. In the θ band, DC emerged as the best markers of seizure onset exhibiting 17.2% (p < 0.01) increase in the ictal state. In contrast, EC in the θ band showed a smaller change of -3.1% (p < 0.01), indicating lower sensitivity. In the β band, both DC and EC demonstrated high sensitivity and significant changes: DC showed a percent change of -12.7% (p < 0.001) and EC had a percent change of -11.1% (p < 0.001). These findings suggest that while both the θ and β bands are highly sensitive to seizure onset, DC and EC thalamic nodes effective markers in both bands.
Neurophysiology