High Inward vs. Low Outward SEEG Connectivity Characterizes Seizure Onset Zones in Focal Epilepsy
Abstract number :
2.015
Submission category :
3. Neurophysiology / 3C. Other Clinical EEG
Year :
2022
Submission ID :
2203997
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:22 AM
Authors :
Jared Shless, BS – Vanderbilt University Medical Center; Graham Johnson, BS – MD/PhD Student, Neurological Surgery, Vanderbilt University School of Medicine; Derek Doss, BE – MD/PhD Student, Neurological Surgery, Vanderbilt University School of Medicine; Aarushi Negi, Research Assistant – Undergraduate Student, Vanderbilt University; Danika Paulo, MD – Resident Physician, Neurological Surgery, Vanderbilt University Medical Center; Victoria Morgan, PhD – Professor, Radiology and Radiological Sciences, Vanderbilt University Medical Center; Sarah Bick, MD – Assistant Professor, Neurological Surgery, Vanderbilt University Medical Center; Dario Englot, MD, PhD – Director of Functional Surgery, Neurological Surgery, Vanderbilt University Medical Center
Rationale: Successful epilepsy surgery requires accurate localization of seizure onset zone(s) (SOZ). Previous work has shown that SOZs can be classified with resting-state stereo-electroencephalography (SEEG) connectivity patterns (Goodale et al., 2020). This work aims to further characterize these connectivity patterns by outlining the inward vs. outward connectivity of SOZs to localize SOZs more accurately in the pre-surgical workup of focal epilepsy.
Methods: This cohort included 81 patients with medically refractory focal epilepsy. Each patient had SEEG recordings obtained at the Vanderbilt University Medical Center (VUMC) epilepsy monitoring unit. This study was approved by the VUMC Institutional Review Board; informed consent was obtained. Continuous SEEG data was obtained for a 20-minute epoch in the resting state and was filtered with passbands of 1-59 Hz and 61-119 Hz. SOZs, non-SOZs, and early propagation zones (PZ: ictal activity spread within 10 seconds) were assigned based on an epileptologist’s review of all ictal events. Across all patients, we evaluated undirected functional connectivity (alpha-band imaginary coherence), as well as inward and outward connectivity (alpha-band partial directed coherence).
Results: We observed that alpha-band (8-12 Hz) inward connectivity (Figure 1B) for SOZs is greater than that of non-SOZs (p < 5E-6) and PZs (p < 5E-3). Further, we observed that the outward connectivity (Figure 1C) behaves in an inverse relationship to that of inward connectivity; outward connectivity is substantially decreased in SOZs compared to non-SOZs (p < 5E-6) and PZs (p < 5E-3). Finally, by computing reciprocal connectivity (Figure 1D), we observed an overall increased group difference between SOZs compared to non-SOZs (p < 5E-6), and PZ (p < 5E-3) as measured by ANOVA (p = 3.13E-13). ANOVA was also used to identify significant differences between these three regions with respect to inward (p = 1.75E-12) and outward (p = 4.95E-10) functional connectivity. _x000D_
Neurophysiology