Frequency-specific Alterations of Functional Hub in Generalized Tonic-clonic Seizure

Chaolin Ma,Huiyan Cheng,Xuhui Chen,Zhe Zhang

doi:10.2991/ijndc.2016.4.4.3

Abstract

Resting-state functional magnetic resonance imaging (fMRI) has revealed aberrant brain functional networks in individuals with generalized tonic-clonic seizure (GTCS). Little is known, however, about these changes in functional hubs across different frequency bands. In this study, we applied a data-driven method named complementary ensemble empirical mode decomposition (CEEMD) to decompose the whole brain BOLD time series into five frequency-specific bands. Then, we compared alterations of frequency-specific functional hub across five different frequency bands in 21 GTCS patients to 22 normal control (NC) subjects. CTCS patients showed aberrant functional hubs predominately at some particular frequency bands and primary in the default mode network (DMN) and the somatomotor network (SMN). Furthermore, we found these hub located in the DMN at a higher frequency band was associated with disease severity. These findings provide an overview of frequency-specific hub, and may be helpful in uncovering abnormal neuronal activity in patients with GTCS at specific frequency bands.

Highlights

Generalized tonic-clonic seizure(GTCS) is a common type of idiopathic generalized epilepsy (ICE)[1]
The FC matrices of each frequency-specific band was presented in Fig. 3 to describe the inter-regional FC subtended by time series components
The principal finding was that CTCS patients showed aberrant functional hubs predominately at some particular frequency bands and primary in the default mode network (DMN)

Summary

Introduction

Generalized tonic-clonic seizure(GTCS) is a common type of idiopathic generalized epilepsy (ICE)[1]. Resting-state functional magnetic resonance imaging (rs-fMRI) has been popularly applied to investigate spontaneous brain neural activity and has widely been performed to reveal intrinsic functional network abnormalities in various epilepsies[3,4]. Neighboring frequency bands within the same neuronal network may compete or interact with each other, which means that the brain intrinsic resting-state functional networks are frequency-dependent[9,10]. Few studies have concentrated on the changes in intrinsic activity that occurs across different frequency bands in patients with GTCS11. These studies usually investigated in resting-state functional connectivity by band passing the data into a priori defined frequency intervals

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Conclusion