Investigation Of The Relationship Between Motor And Cognition Of Different Subtypes Of Parkinson's Disease By Functional Magnetic Resonance Imaging

Object:Parkinson's disease(PD)is a common neurodegenerative disease among the middle and old age.Its characteristic motor symptoms are bradykinesia,rigidity and tremor.PD also has non-motor symptoms,such as cognition impairment.Current researches suggested that the motor symptoms are related with the cognition declination in PD.We investigated the relationship between motor and cognition and related network in PD motor subtypes by resting-state functional magnetic resonance imaging(fMRI).Method:The study included 70 patients and 30 healthy control elderly.According to the rating score of UPDRSIII,the patients were divided into two groups.One is akinetic-rigidity group(AR,n=41)and the other is tremor-dominant group(TD,n=29).All the participants' MRI and clinical data was collected during off state.By independent component analysis,we obtained the frontal parietal network and did the comparison of network among three groups,and did correlation analysis with clinical motor and cognition data.According to the small world theory,imaging data were analyzed using 116 nodes anatomical automatic labeling atlas(AAL).The network and nodal characteristics were compared among groups and correlation analysis with clinical data was done.Result:Demographic data showed that there was no significant difference between three groups in MoCA score,but the orientation score of both AR and TD groups was lower than NC.Only TD's speech score was lower than NC.UPDRSIII,meanTD,meanAR were related with MMSE or MoCA significantly.The analysis of frontal parietal network showed that the functional connectivity(FC)in the left temporal lobe and right occipital lobe in AR was significantly higher than TD and FC in right frontal inferior triangle gyrus in TD was decreased.Further investigation of ROI related FC in whole brain found that the FC between right frontal inferior triangle gyrus and cerebellum was decreased,and the BOLD signal of which was related with clinical data.Both the patients and normal people were showed the characteristics of small world,and the global efficiency(Eg)of TD was decreased.The network global nature was related with orientation score.The nodal weight was different among groups in several nodes in frontal,temporal,and occipital lobes,basal ganglia and cerebellum.The nodal weights were also correlated with clinical data,especially the left fusiform gyrus,right post-central gyrus,left inferior occipital gyrus and right thalamus were correlated with both motor and cognition clinical data.Conclusion:PD patients showed decreased cognitive and motor function in the early stage of the disease.The research showed significant difference ROIs among groups in frontal parietal network and small world network,and these ROIs were found correlated with clinical cognition and motor data.Our results convinced that motor and cognition were significantly correlated and different motor subtypes of PD showed different related network pattern.