Frequency-Dependent Interictal Neuromagnetic Activities in Children With Benign Epilepsy With Centrotemporal Spikes: A Magnetoencephalography (MEG) Study.

Tingting Zhang,Hu Guo,Yuan Gao,Zheng Hu,Xiaoshan Wang,Qi Shi,Caiyun Wu,Yihan Li,Ailiang Miao,Qiqi Chen,Jintao Sun

doi:10.3389/fnhum.2020.00264

Abstract

Objective: This study aimed to investigate interictal neuromagnetic activities in the low- to high-frequency ranges in patients with benign epilepsy with centrotemporal spikes (BECTS), especially those without interictal epileptiform discharges (IEDs).Methods: We studied 21 clinically-diagnosed BECTS patients and 11 age-matched healthy controls (HC) using high-sampling magnetoencephalography (MEG). Neuromagnetic sources were assessed with accumulated source imaging (ASI). The MEG data were analyzed in seven frequency bands. The MEG recordings distinguished BECTS without IEDs (n = 10) from those with IEDs (n = 11) and HC (n = 11).Results: At 1–4 Hz, the neuromagnetic activities in healthy subjects tended to locate at the precuneus/posterior cingulate, while those of the BECTS patients without IEDs tended to locate at the medial frontal cortex (MFC) compared to BECTS patients with IEDs. The MEG source imaging at 30–80 Hz revealed that BECTS patients without IEDs had higher occurrences of interictal brain activity in the medial temporal lobe (MTL) compared to controls and the brain activity strength seemed to be weaker. There was a significant correlation between the source strength of the interictal gamma oscillations of BECTS patients without IEDs and the duration of epilepsy.Conclusions: IEDs might disrupt the default mode network (DMN). Aberrant brain activities in BECTS patients without IEDs were associated with cognitive areas of the brain. The strength of gamma oscillations in the chronic epilepsy state reflected the duration of BECTS.Significance: MEG could reveal the aberrant neural activities in BECTS patients during the interictal period, and such abnormality is frequency-dependent. Gamma oscillations could be used to identify BECTS patients without IEDs.

Highlights

Benign epilepsy with centrotemporal spikes (BECTS, Rolandic epilepsy) is the most common childhood epilepsy syndrome and shows spontaneous remission in adolescence
The current study demonstrated that during the interictal period, frequency-dependent neuromagnetic activities were different between the BECTS patients with and without interictal epileptiform discharges (IEDs), and between BECS without IEDs and controls
At the delta band, we found that BECTS patients without IEDs had predominant activity in the medial frontal cortex (MFC) while the IED group did not

Summary

Introduction

Benign epilepsy with centrotemporal spikes (BECTS, Rolandic epilepsy) is the most common childhood epilepsy syndrome and shows spontaneous remission in adolescence. The age of onset is from one to 14 years old It occurs predominantly between the ages of seven to ten and is more common in males (Panayiotopoulos et al, 2008; Callenbach et al, 2010). A general linear model (Masterton et al, 2010) and an event-related independent component analysis (Masterton et al, 2013) have shown that IED-related brain activation was in the centrotemporal areas in BECTS patients. The transient state of epilepsy is accompanied by IED-related blood-oxygen-leveldependent (BOLD) activation in the regions specific to the syndrome while chronic epileptogenic processes may involve stable changes in functional neural circuit organization (Zhu et al, 2015). Both transient abnormalities and chronic abnormalities may be involved in the development and expression of BECTS

Results

Discussion

Conclusion