The Study Of CSTC Loops In Patients Of Obsessive-compulsive Disorder With Different Medication Status At Resting State

Objective: Obsessive compulsive disorder(OCD)is a chronic disability neuropsychiatric disorder,characterized by persistent intrusive thoughts(obsessions)and repetitive actions(compulsions).Although there are many neuroimaging studies,the pathopsysiology of OCD is still unclear.Because of medication exposure and comorbid mental disorders may confound the results of studies,excluding these factors may contribute to clarify the pathopsysiology of pure OCD.Resting state-functional Magnetic Resonance Imaging had been used to explore the functional connectivities among groups of drug-na?ve patients and medication patients of OCD and healthy controls.Methods: Patients were recruited from the Psychological and psychiatry outpatients in Shanghai mental health center during March 2015 to October 2016,and the healthy controls were recruited during the same time.The Yale Brown Obsessive Compulsive Scale(Y-BOCS),Obsessive Beliefs Questionnaire(OBQ-44),Beck Depression Inventor-II(BDI-II),Beck anxiety inventory(BAI),Barratt Impulsivity Scale-11(BIS-11)were used to assess the clinical symptoms.All of the participants were scanned with magnetic resonance imaging(MRI)for functional connectivity of the whole brain.DPARSF,REST software tools were used to process and analysis the imaging data.Analysis of Variance(anova)were used to compare the changes among three groups.SPSS 19.0 were used to analysis the clinical data.Results:(1)compared with healthy controls,the subscales and total scores of OBQ-44,attentional impulsivity scores and total scores of BIS-11 were significantly higher in OCD patients(p<0.05).(2)The positive functional connectivities between different ROI and brain regions,including orbito-frontal cortex(OFC),Temporal lobe,anterior cingulate cortex(ACC),Supply Motor Area(SMA)were statistically significant among groups of drug-na?ve patients and drug-free patients of OCD and healthy controls.The negative functional connectivities between different ROI and brain regions,including dorsolateral prefrontal cortex(DLPFC),precentral and postcentral cotex,Supply Motor Area(SMA),fusiform gyrus,frontal lobe,inferior parietal were statistically significant among three groups.(3)compared with healthy controls,the structures in limbic affective CSTC loops were hypoactive in OCD patients,structures in sensorimotor loops were hyperactive in OCD patients.Besides,apart from the functional connectivity between ventral striatum and DLPFC were increased,other structures in cognitive loops were hypoactive in OCD patients.(4)Compared with drug-na?ve groups,there was significantly increased connectivity in the limbic/affective loops in the drug-free groups(5)Apart from the cortex-striatal-thalamus-cortex(CSTC)circuitry,there are some other areas in the pathophysiology models of OCD.Conlusion: ?OCD subjects demostrated decreased positive connectivity of the Inferior ventral striatum and OFC,ACC and OFC,putamen and thalamus within limbic(affective)CSTC loops;increased positive connectivity of putamen and SMA,decreased negative connectivity of caudate and SMA within sensorimotor CSTC loops;increased negative connectivity of Inferior ventral striatum and DLPFC within cognitive CSTC loops.?The use of selective serotonin reuptake inhibitors(SSRI)can increased the functional connectivity between ACC and OFC,putamen and thealamus,but also can decreased it between putamen and SMA.?8 weeks off medication before the MRI can not completely wash out the effect of taking SSRIs on the function of brain.?The pathophysiology of OCD are the dysfunction of cortex-striatal-thalamus-cortex(CSTC)circuitry and some other areas beyond it.