Abnormal Functional Connectivity of the Posterior Hypothalamus and Nucleus Basalis of Meynert in People with Mesial Temporal Lobe Epilepsy
Abstract number :
1.257
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2022
Submission ID :
2203988
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:22 AM
Authors :
Jasmine Jiang, BE – Vanderbilt University; Samarati Narasimhan, PhD – Vanderbilt University Medical Center; Graham Johnson, BS – Vanderbilt University; Hernán González, MD, PhD – Vanderbilt University; Derek Doss, BE – Vanderbilt University; Danika Paulo, MD – Vanderbilt University Medical Center; Douglas Terry, PhD – Vanderbilt University Medical Center; Catie Chang, PhD – Vanderbilt University; Victoria Morgan, PhD – Vanderbilt University; Dario Englot, MD, PhD – Vanderbilt University Medical Center
Rationale: While mesial temporal lobe epilepsy (mTLE) is a focal epilepsy, past work has shown that mTLE is associated with long-term brain-network disruptions outside temporal lobe regions. Previous investigations have found perturbed resting-state functional connectivity (FC) between subcortical arousal regions and the neocortex, which may help explain widespread neurocognitive deficits found in mTLE. However, few have studied the connectivity of the posterior hypothalamus (pHTH) and nucleus basalis of Meynert (NBM), structures with important roles in neocortical activation. We sought to characterize resting-state functional MRI (fMRI) connectivity patterns of these important arousal regions with the neocortex in mTLE.
Methods: Our study evaluated resting-state fMRI of 60 preoperative mTLE patients and 95 healthy controls. We first conducted seed-to-voxel connectivity analyses seeded from pHTH, combined anterior-tuberal hypothalamus (i.e. the rest of the hypothalamus; atHTH), and NBM ipsilateral (ipsiNBM) and contralateral (contraNBM) to the epileptogenic zone. Based on results of our vowel-wise analysis, we included regions of most notably perturbed lobes, pHTH, and ipsiNBM in a network-based statistics (NBS) analysis to elucidate a network that best distinguishes patients from controls. Next, we performed age-corrected pairwise region of interest (ROI) analysis on the connections from NBS involving the pHTH and ipsiNBM using a linear fit model generated using only healthy control data. We also compared FC between pHTH and ipsiNBM in patients vs controls. Finally, we correlated patient FC with clinical neurocognitive testing scores for attention and concentration using Pearson correlation. All ROIs were generated using subject-specific atlases. Post-hoc Bonferroni-Holm correction was applied whenever appropriate.
Results: Our voxel-wise analysis demonstrated that pHTH, when compared to atHTH, showed lower FC in widespread regions in mTLE patients when compared to controls. IpsiNBM, but not contraNBM, also showed lower FC in patients. For both pHTH and ipsiNBM, these connectivity differences were concentrated in frontoparietal regions (Figure 1). Our NBS analysis determined a perturbed network of select frontoparietal regions, pHTH, and ipsiNBM that distinguishes mTLE from controls (p < 0.001). Our age-corrected ROI analysis revealed lower FC between pHTH and cortical regions shown in Figure 2 (p < 0.05). We also detected lower FC between pHTH and ipsiNBM in patients (p < 0.05). Finally, we found neurocognitive test scores for attention and concentration were positively correlated to the FC between pHTH and ipsiNBM, suggesting lower FC when compared to controls is associated with worse performance.
Neuro Imaging