Age-Related Arousal Network Connectivity Changes in Temporal Lobe Epilepsy
Abstract number :
2.22
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2023
Submission ID :
428
Source :
www.aesnet.org
Presentation date :
12/3/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Abhijeet Gummadavelli, MD – Neurosurgery One / Littleton Adventist Hospital
Derek Doss, BS – Vanderbilt University Medical Center; Graham Johnson, PhD – Vanderbilt University Medical Center; Jared Shless, BS – Vanderbilt University Medical Center; Monica Jacobs, PsyD – Vanderbilt University Medical Center; Kevin Haas, MD, PhD – Vanderbilt University Medical Center; Sarah Bick, MD – Vanderbilt University Medical Center; Douglas Terry, PhD – Vanderbilt University Medical Center; Catie Chang, PhD – Vanderbilt University; victoria Morgan, PhD – Vanderbilt University Medical Center; Dario Englot, MD, PhD – Vanderbilt University Medical Center
Rationale: Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy and can have effects outside of the temporal lobe, such as loss of consciousness and extra-temporal cognitive deficits. It has been shown that these effects are associated with decreases in functional connectivity between the brainstem ascending reticular activating system (ARAS) and neocortical areas. However, the ARAS network can also change with normal aging. Given the critical role of the ARAS network in cognition and consciousness, we sought to investigate the effect of age and epilepsy duration on ARAS network changes.
Methods: A dataset of resting state functional fMRI (rs-fMRI) of 40 patients with TLE and 40 age/sex-matched healthy controls was obtained. The rs-fMRI data was parcellated with the Harvard-Oxford atlas and the Harvard Ascending Arousal Network atlas to extract both cortical and brainstem structures. We investigated the differences in age-related arousal network node functional connectivity changes between controls and TLE patients. We used the Brain Connectivity Toolbox to calculate graph theory metrics of nodes within the arousal network. Based on 22 pre-defined networks and the arousal network, we also calculated segregation, which represents the how connected a network is to itself compared to the rest of the brain.
Results: In control participants, older age was associated with lower mean network segregation (r=-0.33, p=0.03) and ARAS network segregation (r=-0.41, p=0.01), as prior studies have shown. For patients, older age was also associated with lower mean network segregation (r=-0.34, p=0.04). However, the association between age and ARAS network segregation was non-significant in patients (r=0.14, p=0.40), which was significantly different compared to the relationship in controls (p=0.01, linear mixed effects), suggesting that the ARAS network is affected by TLE (Figure 1). Within the ARAS, the functional connectivity between pedunculopontine tegmental nucleus (PPN) to whole brain demonstrated a significantly different trend across age between patients and controls (p=0.01). Furthermore, PPN to frontoparietal association cortex functional connectivity demonstrated a significantly different trends across age between patients and controls (p=0.02). Finally, PPN to whole brain connectivity was significantly lower in patients with impaired executive function, but not in patients with normal executive function (p< 0.001; Figure 2).
Neuro Imaging