Abstracts

Altered Stability of Dynamic Functional Architecture in Patients with Focal Epilepsy

Abstract number : 2.169
Submission category : 5. Neuro Imaging / 5B. Functional Imaging
Year : 2021
Submission ID : 1825659
Source : www.aesnet.org
Presentation date : 12/9/2021 12:00:00 PM
Published date : Nov 22, 2021, 06:44 AM

Authors :
Jia-Hong Sie, PhD - National Yang Ming Chiao Tung University; Po-Tso Lin, MD – Department of Neurology, Neurological Institute – Taipei Veterans General Hospital; Chien-Chen Chou, MD – Attending Physician, Department of Neurology, Neurological Institute, Taipei Veterans General Hospital; Hsiang-Yu Yu, MD – Chief, Department of Neurology, Neurological Institute, Taipei Veterans General Hospital; Wen-Jui Kuo, PhD – Professor, Institute of Neuroscience, National Yang Ming Chiao Tung University

Rationale: Focal epilepsy is a chronic disorder characterized with spontaneous seizures arising from localized brain areas. Resting-state fMRI research has indicated that these areas can develop enhanced regional functional connectivity (FC). However, FC alterations in dynamic aspect remain relatively unexplored. A more recent work has characterized stability of intrinsic networks over time as published in Neuroimage 2020; 216(1); 116230. We expect that temporal stability of some intrinsic networks will be altered due to abnormal neuronal discharges in epileptic patients, for example the default mode and frontoparietal networks.

Methods: Seventeen adult patients with drug resistant focal epilepsies (epileptogenic hemisphere: 9 right, 5 left, 3 bilateral) underwent 8-min runs during 32-40 min resting-state fMRI scans between September 2018 and December 2020 (age: 31±9 years, 10 females). Fourteen age matched healthy controls were recruited (age: 32±7 years, 7 females). Participants were instructed simply to rest with their eyes closed. Stability of dynamic functional architecture, i.e., temporal stability, was calculated by concordance of dynamic functional connectivity using sliding-window technique with window length of 64 sec and sliding step of 4 sec, resulting in maps across about 105-time windows. We examined differences in voxel-wise stability maps between the two participant groups. For each patient, mean stability of each cluster with significant group difference was further extracted and used for correlation analysis with epilepsy duration.

Results: We found that right temporoparietal junction (TPJ) and cerebellum (crus II) were the two brain regions showing decreased stability in the patient group (p < 0.025, GRF corrected, see Figure 1). In correlation analysis, we found that reduced stability correlated positively with epilepsy duration, but only in the right TPJ (p < 0.05, see Figure 1).
Neuro Imaging