Quantify neuromagnetic network changes from pre-ictal to ictal activities in absence seizures. (15th August 2017)

• Record Type: Journal Article
• Authors: Wu, Caiyun; Xiang, Jing; Sun, Jintao; Huang, Shuyang; Tang, Lu; Miao, Ailiang; Zhou, Yuchen; Chen, Qiqi; Hu, Zheng; Wang, Xiaoshan
• Is Part Of: Neuroscience. Volume 357(2017)
• Page Start: 134
• Page End: 144
• Publication Date: 2017-08-15
• Subjects: CAE childhood absence epilepsy -- DMN default mode network -- EEG electroencephalography -- fMRI functional magnetic resonance imaging -- MEG magnetoencephalography -- SWDs symmetric spike-wave discharges; childhood absence epilepsy -- magnetoencephalography -- effective connectivity -- cortico–thalamo–cortical network -- high-frequency oscillations; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2017.05.038
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Low-frequency neural network was altered among the frontal and parieto–occipito–temporal cortices around absence seizure. High-frequency neural localizations were identified in the deep brain areas and medial frontal cortex in absence epilepsy. The cortex drove the thalamus in both low- and high-frequency bands during the initialization of absence seizure. Abstract: Objective: The cortico–thalamo–cortical network plays a key role in childhood absence epilepsy (CAE). However, the exact interaction between the cortex and the thalamus remains incompletely understood. This study aimed to investigate the dynamic changes of frequency-dependent neural networks during the initialization of absence seizures. Methods: Magnetoencephalography data from 14 patients with CAE were recorded during and between seizures at a sampling rate of 6000 Hz and analyzed in seven frequency bands. Neuromagnetic sources were volumetrically scanned with accumulated source imaging. Effective connectivity networks of the entire brain, including the cortico–thalamo–cortical network, were evaluated at the source level through Granger causality analysis. Results: The low-frequency (1–80 Hz) activities showed significant frontal cortical and parieto–occipito–temporal junction source localization around seizures. The high-frequency (80–250 Hz) oscillations showed predominant activities consistently localized in deep brain areas and medial frontal cortex. The increased cortico–thalamic effective connectivity was observed around seizures in both low- and high-frequency ranges. The direction was predominantly from the cortex to the thalamus at the early time, although the cortex that drove connectivity varied among subjects. Conclusions: The cerebral cortex plays a key role in driving the cortico–thalamic connections at the early portion of the initialization of absence seizures. The oscillatory activities in the thalamus could be triggered by networks from various regions in the cortex. Significance: The dynamic changes of neural network provide evidences that absence seizures are probably resulted from cortical initialized cortico–thalamic network.