Abstracts

Focal Hypertrophy in Mesial Temporal Lobe Epilepsy

Abstract number : 3.237
Submission category : 5. Neuro Imaging / 5A. Structural Imaging
Year : 2021
Submission ID : 1825714
Source : www.aesnet.org
Presentation date : 12/6/2021 12:00:00 PM
Published date : Nov 22, 2021, 06:50 AM

Authors :
Richard Zubal, MD - Klinik für Neurologie, Kantonsspital St.Gallen; Tjardo Postma, MD - UCL Institute of Neurology, Queen Square, London; Lili Long, MD - Xiangya Hospital of Central South University; Matus Velicky, MD - Klinik für Neurologie, Kantonsspital St.Gallen; Daichi Sone, MD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Fenglai Xiao, MD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Sallie Baxendale, PhD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Pamela Thompson, PhD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Jane de Tisi, BA Hons - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Meneka Sidhu, PhD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Lorenzo Caciagli, PhD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, United Kingdom; Gavin Winston, FRCP, PhD - Department of Medicine, Division of Neurology, Queen’s University, Kingston, Canada; Sjoerd Vos, PhD - Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London; Barbara Tettenborn, Prof. - Klinik für Neurologie, Kantonsspital St.Gallen; Christian Baumann, Prof. - Klinik für Neurologie, Universitätsspital Zürich; Bo Xiao, MD - Department of Neurology, Xiangya Hospital, Central South University,; John Duncan, Prof. - Institute of Neurology, University College London; Matthias Koepp, Prof. - Institute od Neurology,University College London; Marian Galovic, MD - Klinik für Neurologie, Universitätsspital Zürich

Rationale: Mesial temporal lobe epilepsy (mTLE) is associated with focal brain atrophy but little knowledge exists on hypertrophy. We assessed areas of brain hypertrophy in mTLE and their clinical correlates.

Methods: We analysed T1-weighted MRI data of 135 patients with unilateral mTLE with pathology-confirmed hippocampal sclerosis (77 left, 58 right) and 47 matched healthy volunteers (HV) using whole-brain voxel-based morphometry (VBM), subcortical volumetry, and shape analysis. We validated our findings in an external cohort (18 patients with mTLE, 18 matched HV). We evaluated the functional implications of the findings on memory encoding using fMRI.

Results: VBM detected increased grey matter volume of the contralateral amygdala in both left (t = 8.7, p < 0.001) and right (t = 7.9, p < 0.001) mTLE. We confirmed the larger volume of the contralateral amygdala using volumetry (left mTLE 1.74 ± 0.16 ml vs. HV 1.64 ± 0.11, p < 0.001; right mTLE 1.79 ± 0.18 ml vs. HV 1.70 ± 0.11, p = 0.002) and surface shape analysis (left mTLE p ≤ 0.005; right mTLE p = 0.006). We validated the hypertrophy of the contralateral amygdala in an external cohort (mTLE 1.91 ± 0.20 ml vs. HV 1.75 ± 0.13, p = 0.009). Contralateral amygdala hypertrophy was associated with poor verbal memory in left mTLE and with more frequent secondarily generalized seizures in right mTLE. Larger volume of the contralateral amygdala correlated with increased functional activation of the parietal memory network on fMRI.
Neuro Imaging