Characterization of Cortical Activity Corresponding to Generalized Spike-and-wave in Juvenile Myoclonic Epilepsy by Gradient Magnetic Field Topography (GMFT)
Abstract number :
2.417
Submission category :
3. Neurophysiology / 3D. MEG
Year :
2022
Submission ID :
2232990
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:29 AM
Authors :
Kota Kagawa, MD, PhD – Department of Neurosurgery, Hiroshima University Hospital; Koji Iida, MD, PhD – Department of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University; Akira Hashizume, MD, PhD – Department of Neurosurgery, Hiroshima University Hospital; Masaya Katagiri, MD, PhD – Department of Neurosurgery, Hiroshima University Hospital; Go Seyama, MD – Department of Neurosurgery, Hiroshima University Hospital; Akitake Okamura, MD, PhD – Department of Neurosurgery, Hiroshima University Hospital; Nobutaka Horie, MD, PhD – Department of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University
This is a Late Breaking abstract
Rationale: Gradient magnetic field topography (GMFT) for magnetoencephalography (MEG) has been developed to demonstrate magnetic-field gradients of epileptic spikes on a volume-rendered brain surface. The purpose of this study is to characterize cortical activity corresponding to generalized spike-and-wave discharges (GSW) in juvenile myoclonic epilepsy (JME) using GMFT.
Methods: Ten patients (age: 14-28 years) with JME were enrolled in this study. We selected maximum 10 interictal MEG spikes corresponding to GSW on simultaneously recorded EEG from each patient. We defined areas with a gradient of over 300fT/cm as activated zones (AZ) on GMFT. We focused on the onset of the AZ in either side of hemisphere. On the volume-rendered brain surface, we divided the hemisphere into five regions: frontal, central, parietal, occipital, and temporal regions. When the onset of AZ appeared with time delay involving bilateral hemispheres, we defined the hemisphere where AZ initially appeared as “preceding hemisphere”, and the contralateral hemisphere as “delayed hemisphere”. We measured the time delay as interhemispheric time difference (ITD).
Results: A total of 65 spikes were analyzed. The preceding hemisphere was left in 29, and right in 36 spikes. In the preceding hemisphere, the onsets of AZ were localized to frontal in 39 (60%), parietal in 22 (34%), and central region in 4 spikes (6%). In the delayed hemisphere, the onsets were localized to the homologous regions in 36 (84%) of 43 spikes. Median ITD was 7 milliseconds (range: 0-20).
Conclusions: The onset of AZ was restricted in frontal to parietal regions both in the preceding and delayed hemispheres with short ITD in spite of “generalized epilepsy”. This MEG study suggested the regional network involvement in JME.
Funding: JSPS KAKENHI Grant Number JP19K16916
Neurophysiology