Resting state basal ganglia network in idiopathic generalized epilepsy

Abstract

The basal ganglia, a brain structure related to motor control, is implicated in the modulation of epileptic discharges generalization in patients with idiopathic generalized epilepsy (IGE). Using group independent component analysis (ICA) on resting-state fMRI data, this study identified a resting state functional network that predominantly consisted of the basal ganglia in both healthy controls and patients with IGE. In order to gain a better understanding of the basal ganglia network(BGN) in IGE patients, we compared the BGN functional connectivity of controls with that of epilepsy patients, either with interictal epileptic discharges (with-discharge period, WDP) or without epileptic discharge (nondischarge period, NDP) while scanning. Compared with controls, functional connectivity of BGN in IGE patients demonstrated significantly more integration within BGN except cerebellum and supplementary motor area (SMA) during both periods. Compared with the NDP group, the increased functional connectivity was found in bilateral caudate nucleus and the putamen, and decreases were observed in the bilateral cerebellum and SMA in WDP group. In accord with the proposal that the basal ganglia modulates epileptic discharge activity, the results showed that the modulation enhanced the integration in BGN of patients, and modulation during WDP was stronger than that during NDP. Furthermore, reduction of functional connectivity in cerebellum and SMA, the abnormality might be further aggravated during WDP, was consistent with the behavioral manifestations with disturbed motor function in IGE. These resting-state fMRI findings in the current study provided evidence confirming the role of the BGN as an important modulator in IGE.

Seizure Frequency Can Alter Brain Connectivity: Evidence from Resting-State fMRI

“…These differences could suggest disease focus, or could be indicators of disease progression and associated compensatory mechanisms. We found that there were several areas of decreased connectivity with associated decreased connectivity of the DMN, as found by many other researchers [7][8]14,35,36 and as has been observed in children with refractory epilepsy, 24 which is known to correlate with disease duration. 6,14 Decreased connectivity was limited to the temporal lobes in patients with infrequent seizures and was widespread and involved the frontal, parietal, and temporal lobes, thalamus, and cerebellum in patients with frequent seizures.…”

Frontal Lobe Epilepsy Alters Functional Connections Within the Brain's Motor Network: A Resting-State fMRI Study

“…The formation of these new networks could therefore cause disruptions and decreases in connection strength within typical motor networks, as observed in the present study. Indeed, an EEG-fMRI study of idiopathic generalized epilepsy showed that decreases in functional connectivity between motor regions were directly correlated to the number of interictal discharges recorded during the fMRI acquisition (Luo et al, 2012). Since interictal discharges may follow pathways of seizure propagation, it could be reasoned that more frequent interictal discharges might establish and maintain atypical motor networks and thus alter connectivity.…”

Increased interhemispheric resting-state functional connectivity in paroxysmal kinesigenic dyskinesia: A resting-state fMRI study

“…Resting-state functional magnetic resonance imaging (fMRI) has been widely used to investigate brain connectivity and networks that exhibit correlated fluctuations in spontaneous brain activity [21]. Robust interhemispheric homotopic resting-state functional connectivity (RSFC) has been shown as one of the most salient aspects of the intrinsic functional architecture of the brain [22,23].…”