Cerebro-Cerebellar Dynamic Functional Connectivity Analysis In Idiopathic Generalized Epilepsy

Idiopathic generalized epilepsy(IGE)is characterized by widespread generalized epilepsy discharges,including three subtypes generalized tonic-clonic seizures,absence epilepsy,juvenile myoclonic epilepsy.A large number of previous studies have found functional abnormalities in cerebellum and some cerebral cortical regions in patients with IGE,these studies provid certain help for the pathological research of IGE.However,most of these studies examined brain dysfunction in IGE from a static perspective.Recently,it has been found that dynamic functional connectivity plays an important role in the integration and regulation of brain function under the stimulation of internal and external environment.Therefore,this paper aims to systematically investigate the abnormal cerebro-cerebellar dynamic functional connectivity in patients with IGE from the perspectives of voxels level,regions level and networks level.In order to investigate the abnormal cerebro-cerebellar dynamic functional connectivity in patients with IGE from the voxel-level,we collected resting state fuctional magntic resonance imaging data from 63 IGE and 65 healthy control.Twenty-six cerebellar regions of AAL template were selected as region of interest,we inveatigated the granger directed connectivity patterns between cerebellum and whole brain.Different granger directed connectivity patterns from whole brain to motor cerebellum and congnitive cerebellum were revealed in granger directed connectivity patterns within the group.Compared with healthy controls,significantly increased granger directed connectivity was found from pre-and postcentral gyrus,parahippocampal gyrus and motor cerebellum to congnitive cerebellum,significantly decreased granger directed connectivity was found from cognitive cerebellum to cognitive cerebellum.Significantly increased granger directed connectivity was found from frontal lobe and middle temporal gyrus to motor gyrus,while significantly decreased granger directed connectivity was found from insula,thalamus,basal ganglia,cingulate gyrus and fusiform to motor cerebellum.These abnormalities may be related to motor and cognitive impairment in patients with IGE.In order to further comprehensively and reliably evaluate the dynamic functional connectivity patterns among cerebelum and whole brain in patients with IGE.The functional connectivity temporal variability was investigated from the brain region leveland the network level,non-overlapping sliding windows and overlapping sliding windows were used reapectively,and hundreds level and thousand level bain template were also used reapectively to verify the stability of the results.The results of two-sample t-test showed that IGE demonstrated significantly increased functional connectivity time variability in insula,cerebellum,pre-and postcentral,basal ganglia and some reions of fronto-parietal network to whole brain in region level.At the network level,significantly increased functional connectivity time variability in within-netowrk level was found in vertrol attention network(VAN),dorsal attention network(DAN)and default mode network(DMN),significantly increased functional connectivity time variability in between-netowrks level was found among VAN,DMN and fronto-partial network(FPN),DAN.Similar results were found across different methods and brain templates.These results suggested that abnormal functional connectivity time variability in the cerebellum,basal ganglia and motor cortex in patients with IGE may be related to motor symptoms.In addition,the abnormal functional connectivity time variability in DMN,DAN,VAN and FPN may be related to the cognitive executive function impairment in patients.The significantly increased functional connectivity time variability in patients with IGE may suggest that excessive frequent information exchange leads to brain dysfunction.In summary,this study comprehensively investigated the abnormal cerebro-cerebellar dynamic functional connectivity of IGE from the voxels level,brain regions level and brain networks level.In patients with IGE,the connectivity between motor related cortex and cognitive cerebellum was significantly increased,the connectivity between cognitive cortical area and motor cerebellum was significantly increased,the connectivity between cognitive cerebellum and cognitive cerebellum was significantly decreased,and the connectivity between motor related cortex and motor cerebellum was significantly decreased.In addition,functional connectivity time variability between cerebellum,basal ganglia,motor cortex and whole brain was significantly increased in patients with IGE,and the functional connectivity temporal variability within and between the DMN,VAN,DAN and FPN was signigicantly increased.These results might reflect the abnormal motor and cognitive functions of patients with IGE and strong brain plasticity of the brain regions damaged in patients with IGE.These results comprehensively reflect the abnormal cerebro-cerebellardynamic functional connectivity in patients with IGE and provide valuable information for further understanding the pathophysiological mechanism of IGE.