Abstracts

Localization of Temporal Lobe Epilepsy Networks from Individualized Atrophy Patterns

Abstract number : 1.263
Submission category : 5. Neuro Imaging / 5B. Functional Imaging
Year : 2022
Submission ID : 2204270
Source : www.aesnet.org
Presentation date : 12/3/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:24 AM

Authors :
Sara Larivière, PhD – Brigham and Women's Hospital / Harvard University; Jessica Royer, PsyD – McGill University; Raul Rodriguez-Cruces, MD, PhD – McGill University; Shahin Tavakol, BSc – McGill University; Yifei Weng, MD, PhD – Nanjing University; Frederic Schaper, MD, PhD – Harvard University; Chifaou Abdallah, MSc – McGill University; Raluca Pana, BSc – McGill University; Andrea Bernasconi, MD – McGill University; Neda Bernasconi, MD, PhD – McGill University; Luis Concha, MD, PhD – National Autonomous University of Mexico; Zhiqiang Zhang, MD, PhD – Nanjing University; Birgit Frauscher, MD, PhD – McGill University; Michael Fox, MD, PhD – Harvard University; Boris Bernhardt, PhD – McGill University

Rationale: Approximately 30% of individuals with temporal lobe epilepsy (TLE) do not respond to medications and need new treatments. Cumulating evidence has underscored the importance of brain networks, as opposed to single brain regions, in understanding the disease and consequently generate effective surgical or neuromodulation treatments. Yet, the exact location of these networks is unknown. Here, we identified the human brain networks involved in TLE using a recently validated technique termed “atrophy network mapping” [1] and examined their embedding within known macroscale hierarchies.

Methods: Participants: We studied 83 adult patients with drug-resistant TLE (39 males, mean age±SD = 30.2±10.3 years, 44 left-sided focus) and 120 healthy controls (54 males, mean age±SD = 29.8±9.5 years). All participants underwent high-resolution T1w and functional MRI. Atrophy network mapping. Surface-based, vertexwise atrophy maps were obtained by comparing cortical thickness in each patient with TLE against an age-, sex-, and site-corrected normative model derived from healthy controls. Networks of brain regions functionally connected to each patient’s atrophy location were determined using individualized seed-based functional connectivity (Figure 1A). Associations with macroscale hierarchies: To relate our findings to large-scale topographic principles of brain organization, atrophy-based networks in TLE were spatially correlated with the principal connectome gradient [2] and stratified based on large-scale functional communities [3].

Results: Patients with left and right TLE showed widespread atrophy across the cortex (Figure 1B), spanning bilateral fronto-central and parietal cortices, as well as ipsilateral mesiotemporal cortex (pFDR< 0.05; Figure 1C). Despite the heterogeneity of atrophied regions at the single-subject level, we found that up to 68.2% (left TLE) and 74.3% (right TLE) of patients had atrophied regions that were functionally connected to the same brain regions (i.e., vertices) in bilateral sensorimotor, superior parietal, and occipital cortices (Figure 2A). These regions significantly colocalized with visual, sensorimotor, and attention networks (pperm< 0.0001), networks which form the sensory apex of the hierarchical connectome gradient (pspin< 0.0001; Figure 2B) [2].
Neuro Imaging