A Study Of Resting-state Functional Magnetic Resonance Imaging On Brain Function In Patient With First-episode Obsessive Compulsive Disorder

Object:This paper attempts to study the activation pattern of brain neurons in the patients with first-episode obsessive-compulsive disorder(OCD)at resting.Functional Connectivity(FC)is also used to explore the change of function connectivity in abnormal-activity brain area and the whole brain,with the aim to study the correlation between disease course of patients and their activation pattern of brain neurons.Methods:According to the diagnostic criteria of OCD in American Diagnostic and Statistical Manual of Mental Disorders Fourth Edition(DSM-IV),26 patients with fist-episode OCD and 25 healthy sex-,age-and education degree-matched controls received resting state fMRI scanning runs.The fMRI data were processed by statistical parametric mapping(SPM8),Data Processing Assistant for Resting-State fMRI Analysis Toolkit(DPARSFA),and Resting State fMRI Data Analysis Toolkit.(REST)software on Matlab2012a.Two sample T-test was used to detect the difference of ReHo value between the OCD group and HC group.Take those brain regions with different ReHo value(Thalamus R,Thalamus L,Paracentral_Lobule_R,Postcentral R,Angular L)as seed region respectively for the functional connectivity analysis with the whole brain.with age as concomitant variable,Pearson correlation analysis was adopted to study the correlation between the course time of patients and their ReHo values of whole brain.All the statistical thresholds were set to P<0.005,Alphasim(P<0.005)is used and processing results were overlaid and displayed on Colin 27 Average Brain Template.Results:1.General clinical data comparisonThe difference between 26 patients with OCD and 25 patients in healthy group,in the aspect of gender(χ2=2.372,P=0.124),age(t=0.908,P=0.37)and educational degree(t=-1.784,P=0.08),was not statistically significant.2.ReHo value comparison between OCD group and HC groupCompared with HC group,the ReHo value of OCD group decreased in brain regions(Thalamus_L,Thalamus_R,Paracentral_Lobule_R,Postcentral_R)and increased in the Angular L region.3.Functional connectivity comparison between those brain regions(Thalamus R,Thalamus_L,Paracentral_Lobule_R,Postcentral_R,Angular L)which acted as seed region respectively and the whole brain.3.1 Brain functional connectivity comparison with the Thalamus L as seed region.Compared with HC group,OCD group demonstrated less functional connectivity in brain regions(Frontal_Mid_L,bilateral Thalamus,Caudate R,Hippocampus_R)and more functional connectivity in those brain regions(Parietal Lobe-L,bilateral Precentral,bilateral Postcentral,bilateral Temporal-Pole,bilateral Lingual,bilateral Calcarine,bilateral Cuneus,bilateral Precuneus,bilateral Paracentral Lobule,bilateral Cerebellum,bilateral Temporal-Lobe,Fusiform R).3.2 Brain functional connectivity comparison with the Thalamus R as seed regionCompared with HC group,OCD group demonstrated less functional connectivity in brain regions(Frontal_Sup_L,Frontal-Mid_L,bilateralm Cingulum_Mid,bilateral Cingulun_Ant,bilateral Thalamus,Marginal R)and more functional connectivity in those brain regions(bilateral Temporal_Lobe,bilateral Cerebellum,Fusiform L,bilateral Occipital Lobe,bilateral Cuneus Lobe,bilateral Calcarine,bilateral Lingual).3.3 Brain functional connectivity comparison with the Angular L as seed regionCompared with HC group,OCD group demonstrated less functional connectivity in brain regions(Temporal_Lobe-L,bilateral Insula,bilateral Caudate,bilateral Putamen,Frontal_Mid_R,Supp_Motor_Area_L)and more functional connectivity in those brain regions(bilateral Paracentral_Lobule,Supp_Motor_Area_R,Calcarine_R,Lingual_R,Frontal_Mid_R,Precentral_R,Temporal_Lobe_R,Postcentral_R).3.4 Brain functional connectivity comparison with the Paracentral_Lobule_R as seed regionCompared with HC group,OCD group demonstrated less functional connectivity in bilateral Paracentral Lobule,bilateral Precuneus,bilateral Postcentral,and bilateral Precentral.Compared with HC group,there is no brain areas shows more functional connectivity.’3.5 Brain functional connectivity comparison with the Postcentral_R as seed regionCompared with HC group,OCD group demonstrated less functional connectivity in Postcentral_R,Precentral_R,and Parietal_Lobe_R.Compared with HC group,there is no brain areas shows more functional connectivity.4.Correlation analysis on disease course of patients and whole brain function activity.The negative correlation between disease course and ReHo value lies in the bilateral Orbitofrontal cortex.Conclusion:1.At resting,patients with OCD may have abnormal functional activity in multiple brain regions,such as Thalamus,Paracentral__Lobule_R,Postcentral_R,Angular_L and so on.2.The pathogenesis of obsessive-compulsive disorde neural network is complicated,there are multiple abnormal neural circuits,cortico-striatal-thalamo-cortical demonstrated less functional connectivity;Functional connectivity between Thalamus and postmedian brain shows a compensatory increase,and abnomal function activity exists in Parietal-striatal-thalamo-cortical.The functional connectivity among three resting state networks(default network,salience network,central executive network)of patients lose balance.3.The longer is OCD course,the worse is the functional activity of frontal cortex region.