EEG Oscillatory Networks in Peri-Ictal Period of Absence Epilepsy

Zhiye Li; Jialing Huang; Wei Wei; Sili Jiang; Hong Liu; Hua Luo; Jianghai Ruan

doi:10.3389/fneur.2022.825225

EEG Oscillatory Networks in Peri-Ictal Period of Absence Epilepsy

Front Neurol. 2022 Apr 25:13:825225. doi: 10.3389/fneur.2022.825225. eCollection 2022.

Authors

Zhiye Li^{1

2}, Jialing Huang^{1

2}, Wei Wei^{1

2}, Sili Jiang³, Hong Liu^{1

2}, Hua Luo^{1

2}, Jianghai Ruan^{1

2}

Affiliations

¹ Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.
² Laboratory of Neurological Diseases and Brain Function, Luzhou, China.
³ Department of Neurology, Suining Central Hospital, Suining, China.

Abstract

Objective: To investigate the dynamical brain network changes before and after an absence seizure episode in absence epilepsy (AE).

Methods: 21 AE patients with a current high frequency of seizures and 21 sex- and age-matched health control (HC) who reported no history of neurological or psychiatric disorders and visited the hospital for routine physical examinations were included. Each included subject underwent a 2-h and 19-channel video EEG examination. For AE patients, five epochs of 10-s EEG data in inter-ictal, pre-ictal, and post-ictal states were collected. For the HC group, five 10-s resting-state EEG epochs were extracted. Functional independent components analysis (ICA) was carried out using the LORETA KEY tool.

Results: Compared with the resting-state EEG data of the HC group, the EEG data from AE patients during inter-ictal periods showed decreased alpha oscillations in regions involving the superior frontal gyrus (SFG) (BA11). From inter-ictal to pre-ictal, SFG (BA10) showed maximum decreased delta oscillations. Additionally, from pre-ictal to post-ictal, superior temporal gyrus (STG) (BA 22) presented maximum increased neural activity in the alpha band. Moreover, compared with inter-ictal EEG, post-ictal EEG showed significantly decreased theta activity in SFG (BA8).

Conclusion: The changes in SFG alpha oscillations are the key brain network differences between inter-ictal EEG of AE patients and resting-state EEG of HCs. The brain networks of EEG oscillatory during peri-ictal episodes are mainly involving SFG and STG. Our study suggests that altered EEG brain networks dynamics exist between inter-ictal EEG of AE patients and resting-state EEG of HCs and between pre- and post-ictal EEG in AE patients.

Keywords: absence epilepsy; brain networks; electroencephalography; independent component analysis; seizures.