Comparative Study Of Regional Homogeneity Between Bipolar Disorder Patients In Depressive State And Manic State: A Resting-state Functional Magnetic Resonance Imaging Study

Objective: In this study,resting-state functional magnetic resonance imaging and regional homogeneity was used to investigate the abnormalities and similarities of spontaneous neural activity between BD patients in depressive state and manic state in order to find the base of spontaneous neural activity in BD associated with the mechanism of pathophysiology and provide evidence for differentiating the two phases in order to make correct diagnosis and initiate proper treatment.Methods: We acquired the resting-state functional MRI data of 51 bipolar disorder patients in depressive state(BDD),25 bipolar disorder patients in manic state(BDM)and 54 age,gender and education year matched healthy controls(HC).Analysis of variance(ANOVA)test was used to compare the difference of ReHo values among BDD,BDM and HC across the whole brain.Then post-hoc T-test was used to compare the difference between each two groups.Results: 1.Significant differences were found in several regions including the left inferior frontal orbital gyrus,left superior temporalis gyrus,left insular lobe cortex,right angular gyrus and right angular gyrus of inferior parietal lobe among the three groups(p < 0.005,corrected).2.BDD and BDM patients both showed significant higher ReHo than HC in the left inferior frontal orbital gyrus.The increasing trend of ReHo in BDM group is between BDD group and HC group.In this region,BDD and BDM patients showed no significant difference.3.BDD and BDM patients both showed significant lower ReHo than HC in left superior temporalis gyrus,left insular lobe cortex.And in these regions,BDM showed significant lower ReHo than BDD patients,and in this region,BDD and BDM patients showed significant difference.4.HC and BDM patients both showed significant higher ReHo than BDD in the right angular gyrus,right angular gyrus of inferior parietal lobe,But in these regions,HC and BDM patients showed no significant difference.Conclusion: 1.Our results showed that BD had similar and specific changes in ReHo in different states.2.Implying the left inferior frontal orbital gyrus might be thedisease-related brain alterations.3.Suggesting these areas are the disease-related brain alterations,and these regions may suggest that the degree of functional lesion can be used to discriminate the two phases of BD.4.Implying these areas might be the unique changes of BDD and phase-related brain alterations.