Resting-state Functional Magnetic Resonance Imaging Study Of Cerebellar Functional Connectivity In Patients With Obsessive-compulsive Disorder

BackgroundObsessive compulsive disorder(OCD)is a kind of psychiatric disease with early onset age and longer duration of recurrent.The core symptoms of OCD are obsessions and compulsions,and OCD patients also have the deterioration of cognitive functions such as attention,memory,decision-making ability and inhibition function.Structural and functional neuroimaging studies have indicated that the cortico-striato-thalamo-cortical(CSTC)circuit contributes to the pathophysiology of obsessive compulsive disorder(OCD).Previous studies have suggested that the cerebellar-cerebral functional connectivity is closely related to the above cognitive functions,and cases of OCD caused by cerebellar organic injury have been mentioned in some case reports.However,there are few studies on the cerebellum of obsessive-compulsive disorder,and the conclusions are inconsistent.And previous study investigating cerebellar-cerebral functional connectivity has relied on a priori-defined seeds from specific networks,which may affect the results due to differences in the experimental samples.In this study,we aimed to explore the connectivity alterations of the cerebellum in OCD under resting-state in a hypothesis-free approach.ObjectivesTo reveal the alterations of cerebellar connectivity in patients with OCD under resting state.MethodsThirty patients with OCD and twenty-six age and sex matched healthy controls(HC)were underwent functional magnetic resonance imaging(fMRI)scanning at resting state.Regional cerebral function was evaluated by measuring the fraction of amplitude of low-frequency fluctuation(fALFF).Regions with fALFF alterations were used as seeds in whole-brain functional connectivity(FC)analysis.ALL patients were scored using the Yale-Brown Obsessive Compulsive Scale(Y-BOCS).All participants were collected functional resting magnetic resonance data,and calculate the whole brain of fALFF value.An independent sample T test was used to compare the differences of fALFF and FC between the two groups.In addition,regions showing differences between OCD patients and HC were selected as region of interest(ROI)for whole seed-based FC analysis.Pearson correlation analysis Correlation analysis was performed to identify the association between functional neural correlates and OCD symptom severity evaluated using Yale-Brown Obsessive Compulsive scale(Y-BOCS)was used to analyze the relationship between Y-BOCS score and fMRI data.ResultsCompared with the HC group,OCD group showed significantly increased mfALFF value in Crus II region,Lobule VIII region on the left side and Lobule VIII region on the right side.The mfALFF values in the Crus II region of the cerebellum was positively correlated with the Y-BOCS total scores.The results of FC analysis showed weakened between left Crus II and the right dorsal striatum and ventral striatum,the left Lobule VIII and the right dorsal striatum,and between the right Lobule VIII and the right dorsal striatum and right anterior cingulate in OCD,compared to HC.The FC values between left Crus II and right dorsal striatum were negatively correlated with Y-BOCS total scores.ConclusionsThe cerebellum may play an essential role and alteration of functional connections between the cerebellum and the CSTC circuit may be involved in the pathophysiology of OCD.