A Study Of Intrinsic Brain Activity In Benign Epilepsy Of Childhood With Centrotemporal Spikes

Objective:The patients with rolandic epilepsy are usually associated with neural circuit dysfunction, particularly during the transient active state characterized by interictal epileptiform discharges (IED). Little is known, however, about neural circuits abnormalities in rolandic epilepsy without interictal epileptiform discharges, and whether such abnormal neural circuits would be used to differentiate rolandic epilepsy individuals without interictal epileptiform discharges from the healthy control.Methods:We collected resting-state functional magnetic resonance imaging (fMRI) and simultaneous electroencephalography from children with rolandic epilepsy (n=43) and healthy age-matched controls (n=28). We used simultaneous EEG to group rolandic epilepsy patients with IED (IED group, n=20) and without IED (non-IED group, n=23). Intrinsic brain activity was calculated among three groups using amplitude of low frequency fluctuation (ALFF). Then we made one-way ANOVA for the ALFF of the three groups to find group differences of intrinsic brain activity. Moreover, we grouped patients with left IED and right IED and compared the IQs and amplitude of low frequency fluctuation (ALFF) among patients with left IED and right IED and healthy controls. At last, we made multivariate pattern analysis to differentiate rolandic epilepsy patients without IED from healthy controls.Results:We found significant differences among the three groups by one-way ANOVA in the right rectus gyrus (REC), right rolandic operculum (ROL), right thalamus (THA), left middle frontal gyrus (MFG), right postcentral gyrus (PoCG), and left superior parietal gyrus (SPG). Compared with healthy controls, we found distinguished intrinsic activity abnormality in thalamus, PoCG, ROL, REC, and SPG for IED group. In addition, we found distinguished intrinsic activity abnormality in MFG, REC, ROL and PoCG in non-IED group compared with healthy controls. Moreover, the ALFF of the right thalamus positively correlated with the number of IEDs observed during EEG-fMRI recordings. The ALFF value of the left SPG negatively correlated with performance IQ in the IED group (r=-0.4822, P=0.05) and all patients (r=-0.3299, P=0.0376), but not in the non-IED group. In addition, we found that patients with left IED and right IED had abnormal ALFF in right rolandic operculum and supramarginal gyrus compared with healthy controls. Using multivariate pattern classification analysis, we were able to differentiate rolandic epilepsy individuals without interictal epileptiform discharges (non-IED group) with healthy controls (92.16%accuracy, P<0.001).Conclusions:Rolandic epilepsy patients with or without interictal epileptiform discharges have intrinsic brain activity abnormalities in the right PoCG and ROL. The right thalamus may be associated with discharges of rolandic epilepsy. Intrinsic brain activity and multivariate pattern classification techniques are promising tools to differentiate rolandic epilepsy without interictal epileptiform discharges from healthy controls.