Altered Amygdala Volumes and Microstructure in Focal Epilepsy Patients with Tonic-Clonic Seizures and Post-Ictal Central Apnea
Abstract number :
2.45
Submission category :
5. Neuro Imaging / 5A. Structural Imaging
Year :
2022
Submission ID :
2232929
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Claudia Zeicu, MBBCh – University College London; Antoine Legouhy, PhD – Department of Clinical and Experimental Epilepsy – University College London; Catherine Scott, Clinical Physiologist – Department of Neurophysiology – The National Hospital of Neurology and Neurosurgery; Joana Oliveira, Clinical Physiologist – Department of Neurophysiology – The National Hospital of Neurology and Neurosurgery; Gavin Winston, MD PhD – Department of Clinical and Experimental Epilepsy – University College London; Sjoerd Vos, PhD – Centre for Microscopy, Characterisation, and Analysis – The University of Western Australia; Maria Thom, MBBS – Institute of Neurology – University College London; Samden Lhatoo, MD – Department of Neurology – University of Texas Health Sciences Center at Houston; Hui Zhang, PhD – Department of Computer Science, Faculty of Engineering Science – University College London; Ronald Harper, MD PhD – UCLA Brain Research Institute; Beate Diehl, MD PhD – Department of Neurophysiology – The National Hospital of Neurology and Neurosurgery
This is a Late-Breaking abstract.
Rationale: The mechanisms of sudden unexpected death in epilepsy (SUDEP) are not yet well understood. Focal to bilateral tonic-clonic seizures (FBTCS) are a major risk factor, and postictal central apnea (PICA) likely increases SUDEP risk further. Here, we determined volume and microstructure of the amygdala, a key structure that can trigger apnea in people with focal epilepsy, stratified by presence or absence of FBTCS and PICA.
Methods: Participants were recruited prospectively during presurgical investigations; video EEG (VEEG) and respiratory patterns were collected. We acquired high-resolution T1-weighted anatomical and multi-shell diffusion images, and computed neurite orientation dispersion and density imaging (NODDI) metrics. Amygdala volumetric and microstructure alterations were compared between healthy individuals (n=69), patients with either only-focal seizures (historically, and captured on VEEG) (n=73), or only focal to bilateral tonic-clonic seizures (FBTCS) (n=30). The TCS group was further subdivided according to the presence of PICA, verified by VEEG. Amygdala volume and microstructure differences between groups were assessed using a multivariate analysis of covariance, controlling for age and sex.
Results: The mean ages for the cohorts were as follows: healthy controls (40.82 ± 12.95 years), FBTCS seizure cohort subjects (30.84 ± 6.38 years) and focal only seizure cohort (34.58 ± 11.98 years); 83 of the 172 individuals were male. Left amygdala volumes were significantly increased in the FBTCS cohort compared to healthy controls (p < 0.001) and the focal cohort (p < 0.001). Right amygdala volume in the FBTCS group again showed a significant increase in amygdala volume compared to healthy controls (p < 0.001) and the focal only group (p=0.008). Patients with recorded PICA had the highest increase in bilateral amygdala volume out of the FBTCS cohort. The left and right amygdala neurite density index (NDI) values were significantly decreased in both the Focal and FBTCS groups relative to healthy controls (p < 0.001), with the FBTCS group being the lowest of the two (Figure 1). A significant decline in NDI in the PICA subgroup vs the FBTCS group emerged (p=0.004). DTI showed similar diffusivity (MD) and fractional anisotropy (FA) values in the amygdala between groups and healthy controls.
Neuro Imaging