The Research Of Resting-state FMRI In Parkinson’s Disease-associated Mild Cognitive Impairment Patients

Objectives:The aim of this study was to compare regional homogeneity(ReHo)changes in Parkinson’s disease mild cognitive impairment(PD-MCI)patients with respect to normal controls(NC)and those with cognitively normal PD(PD-CN).Further,the study investigated the relationship between ReHo changes in PD patients and clinical indices.Methods:Thirty PD-MCI,19 PD-CN,and 21 NC subjects were enrolled.Resting state functional magnetic resonance imaging data of all subjects was collected,and regional brain activity was measured for ReHo.Analysis of covariance for ReHo was determined between the PD-MCI,PD-CN,and NC groups.Spearman rank correlations were assessed using the ReHo maps and data from the clinical indices.Results:In comparison with NC,PD-CN patients showed significantly higher ReHo values in the right middle frontal gyrus(MFG)and lower ReHo values in the left supramarginal gyrus,bilateral inferior parietal lobule(IPL),and the right postcentral gyrus(PCG).In comparison with PD-CN patients,PD-MCI patients displayed significantly higher ReHo values in the the right PCG,left middle occipital gyrus(MOG)and IPL.No significant correlation between ReHo indices and the clinical indices was observed.Conclusion:Our finding speculated that decreases in ReHo in the default mode network(DMN)may appear before PD-related cognitive impairment.In order to preserve executive attention capacity,ReHo in the right MFG in PD patients lacking cognition impairment increased for compensation.PD-MCI showed increased ReHo in the left MOG,which might have been caused by visual and visual-spatial dysfunction,and increased ReHo in the left IPL,which might reflect network disturbance and induce cognition deficits.Objectives:The aim of this study was to compare degree centrality(DC)changes in PD-MCI patients with respect to NC and those with PD-CN.Further,the study investigated the relationship between DC changes in PD patients and clinical indices.Method and materials:Thirty-one PD-MCI,30 PD-CN,and 30 NC subjects were enrolled.Resting state functional magnetic resonance imaging data of all subjects was collected,and intrinsic functional connectivity pattern of voxel-level whole brain functional network was measured for DC.Analysis of covariance for DC was determined between the PD-MCI,PD-CN,and NC groups.Spearman rank correlations were assessed using the DC maps and data from the clinical indices.Results:In comparison with NC,PD-CN patients showed significantly higher DC values in the left caudate nucleus(CAU).In comparison with PD-CN patients,PD-MCI patients displayed significantly higher DC values in the right posterior cingulate cortex(PCC)and MFG,and lower DC values in the right fusiform gyrus(FFG)and middle temporal gyrus(MTG).In comparison with NC,PD-MCI patients showed significantly higher DC values in the superior frontal gyrus(SFG),and lower DC values in the right calcarine(CAL)and MTG.Average DC values in the PCC of PD-MCI patients were found positively correlated with scores of MMSE(P=0.039,r=0.392).Conclusion:Our findings speculated left CAU may be a key hub in whole brain functional network among PD-CN patients.Right PCC and MFG may be a key hub in whole brain functional network among PD-MCI patients.The functional integration of whole brain functional network of the posterior cortex such as right FFG,CAL and MTG were decreased among PD-MCI patients.The changes of DC among PD-MCI patients were presented as right hemisphere lateralization.