The Study Of Structural And Resting-state Functional Magnetic Resonance Imaging In Motor Subtypes Of Parkinson’s Disease

Objective:(1)To observe the characteristics of spontaneous brain activity and connectivity in patients with Parkinson’s disease(PD)by resting-state functional magnetic resonance imaging combined with low-frequency fluctuation amplitude and functional connectivity(FC);(2)To investigate the changes in gray matter volume and characteristics of spontaneous brain activity at resting-state in different motor subtypes of Parkinson’s disease,and explore the correlation between these differences and clinical manifestations.Methods:(1)3.0T BOLD rs-f MRI and high-resolution 3D-T1 WI scans were obtained from 36 PD patients(PD group)and 31 healthy controls(HC group)matched for age,gender,and education,and then performed image processing and obtained amplitude of low frequency fluctuation(ALFF),fractional amplitude of low frequency fluctuation(f ALFF),and percent amplitude of fluctuation(Per AF)normalized values for statistical analysis and comparison.Seed-based FC was then performed between the differential ALFF,f ALFF,and Per AF based brain regions and the rest of the voxels throughout the brain.The correlations between ALFF,f ALFF and Per AF in abnormal brain region and unified Parkinson’s Disease Rating Scale(UPDRS)score,course of disease and Mini-Mental State Examination(MMSE)score in PD patients was analyzed.The images were analyzed and compared by different preprocessing methods to observe the stability of the results.(2)56 PD patients were enrolled,including 35 postural instability/gait difficulty(PIGD),21 tremor-dominant(TD),and 40 HCs.All enrolled subjects underwent BOLD rs-f MRI and high-resolution 3D-T1 WI scans and clinical assessments.MR images were analyzed by voxel-based morphometry(VBM),ALFF and Per AF to observe gray matter structure and spontaneous brain activity differences among the three groups.The correlations between GMV,Per AF values in abnormal brain regions and the unified Parkinson’s Disease Rating Scale(UPDRS)score,Mini-Mental State Examination(MMSE)score,PIGD score,TD score and course of disease.Results:(1)Compared with the HC group,the ALFF value of the left precuneus in PD patients was significantly decreased;the f ALFF values of the right medial superior frontal gyrus and left posterior cingulate gyrus were significantly decreased;the m Per AF value of the inferior frontal gyrus was significantly decreased(Alphasim adjusted P < 0.05).In PD group,FC decreased between left precuneus and bilateral angular gyrus,left dorsolateral superior frontal gyrus,and enhanced with right insular operculum inferior frontal gyrus.In the PD group,FC between the left posterior cingulate gyrus and the left precuneus,right middle orbital gyrus,right dorsolateral superior frontal gyrus,right medial superior frontal gyrus,and right angular gyrus was reduced,and FC was enhanced in the right inferior insular gyrus,right supramarginal gyrus,and left medial and paracingulate gyrus(FWE adjusted P < 0.05).The f ALFF values of the right medial superior frontal gyrus(r=-0.352,P=0.035)was negatively correlated with the course of disease(P < 0.0025).(2)Compared with the HC group,the gray matter volume of the right hippocampus,the right temporal pole: superior temporal gyrus,the right middle temporal gyrus and the left parahippocampal gyrus was significantly reduced in the PIGD group.Compared with the HC group,the Per AF value of the right rectus gyrus was significantly decreased and the left insular inferior frontal gyrus was significantly increased in the PIGD group,and the Per AF value of the right medial superior frontal gyrus showed decreased in the TD group(P < 0.05,GFR correced for).The GMV of the right hippocampus(r=0.541,P=0.001)in PIGD patients was positively correlated with the MMSE score(P < 0.0012).Conclusion:(1)The combined method of low-frequency fluctuation amplitude and FC of resting-state functional magnetic resonance can more comprehensively show the differential areas in the brain regions of PD patients,mainly stabilized in the default mode network regions and the prefrontal cortex.(2)Both PIGD and TD patients have abnormalities in frontal spontaneous brain function activity,and PIGD patients have atrophy of temporal gray matter volume,which is associated with cognitive function.(3)Per AF can play a role in the discovery of brain function changes in PD disease and different subtypes of PD.