Parkinson's Disease Is Based On Functional Connectivity Analysis Of The Subthalamic And Putamen

Part 1:Research about the functional connectivity of MRI based on the subthalamic nucleus in Parkinson's diseaseObjectiveParkinson's disease(PD)is the second most common progressive neurological degenerativedisorder caused by dopamine deficits in the substantia nigra pars compacta.Impairment of the respective functions of parallel cortico-basal ganglia-thalamo-cortical circuits causes various symptoms.Functional connectivity(FC)between the subthalamic nucleus(STN)and the sensorimotor cortex is increased in off-medication patients with Parkinson's disease(PD).However,the status of FC between STN and sensorimotor cortex in on-medication PD patients remains unclear.We tested whether changes in FC between STN and whole brain may exist,as well as the correlation with the motor symptom,because motor symptoms exist after drug administration.MethodsIn this study,we conducted a study of 36 PD patients and 31 healthy controls in the Department of Geriatrics,Nanjing Brain Hospital between July 2015 and March 2016.All the participants were scanned with MRI to obtain BOLD signal and anatomical images.Two-sample T test was used to study the change in FC pattern of the STN,the FC difference of the STN was correlated motor symptoms.Patients were classified as tremor dominant(TD)PD and postural instability and gait difficulty dominant(PIGD)PD based on the motor symptoms,we extracted the z-values of FC between STN and changed ROI,and compared the FC pattern between the two subtypes.ResultsCompared with healthy controls,both bilateral and right STN showed increased FC with the right sensorimotor cortex in PD patients,whereas only right STN FC was correlated with left-body rigidity scores and LEDD in all PD patients.An additional subgroup analysis was performed according to the ratio of mean tremor scores and mean postural instability and gait difficulty(PIGD)scores,Only the PIGD subgroup showed the increased FC between right STN and sensorimotor cortex under medication.ConclusionsIncreased FC between the STN and the sensorimotor cortex was found,which was related to motor symptom severity in on-medication PD patients.Anti-PD drugs may influence the hyperdirect pathway to alleviate motor symptoms with the more effect on the termor subtype.Part 2:Functional connectivity analysis of putamen between different subtypes of Parkinson's diseaseObjectiveImpairment of the respective functions of parallel cortico-basal ganglia-thalamo-cortical circuits causes various motor symptoms of Parkinson's disease,the Tremor Dominant(TD)subtype and the Postural Instability and Gait Disorder(PIGD),are distinguished by a spectrum of clinical motor symptoms.So we intend to investigate the changed brain areas of functional connectivity(FC)patterns of putamen between different subtypes of Parkinson's disease(PD)and healthy controls,and explore its clinical significance.MethodsWe conducted a study of 39 PD patients and 31 healthy controls in the Department of Geriatrics,Nanjing Brain Hospital between July 2015 and March 2016,and PD patients were divided into 16 cases of tremor dominant PD patients and 23 cases of PIGD dominant PD patients,all participates were scanned with 3.0T MRI for resting state BOLD signals and axial anatomical images.The bilateral putamens were defined as regions of interest,a voxel-wise FC analysis was performed by computing the temporal correlation between the mean time series of the left or right putamen and the time series of each voxel within the whole brain.Within-group multiple comparisons,all T maps had a threshold of p<0.005,while the cluster extent was calculated according to alphasim correction.The last,correlation between the FC strength of the bilateral STN and motor symptoms have been evaluated with a threshold of p<0.05,and the cluster extent was also calculated according to alphasim correction.ResultsCompared with PIGD dominant group,TD dominant group showed increased FC between bilateral STN and right cerebelum lobules VI and cerebelum crus I.While compared with healthy controls,tremor dominant PD patients showed increased FC between left putamen and bilateral cerebelum crus I,right cerebelum lobules ?,right thalamus,left paracentral lobule,right inferior occipital lobule,cerebellar vermis,fusiform gyrus,left supplementary motor area,increased FC between right putamen and right cerebelum crus I,right cerebelum lobules ?,right thalamus,bilateral paracentral lobule,right inferior occipital lobule,right inferior tempotal gyrus,bilateral supplementary motor area and left sensorimotor cortex were also shown in TD patients,TD dominant group showed increased FC between right putamen and right thalamus compared with healthy controls.The FC strength between the left putamen and right cerebelum lobules ? showed positive relationship with tremor scores in TD dominant group,and the FC strength between right putamen and left sensorimotor cortex showed negative relationship with PIGD scores.While in PIGD dominant group,the FC strength between left putamen and right thalamus showed negative relationship with TD scores.ConclusionsDifferent subtypes of Parkinson's disease have distrinct putamen FC pattern,PIGD dominant PD showed an increased activity in basal ganglia-thalamus-cortical loops,and the functional connectivity of the loop gradually diminished as the PIGD symptoms increased.TD dominant PD also showed the overactivity of basal ganglia-thalamic-cortical loops.With the increase of tremor symptoms,basal ganglia-thalamus-cortical loop function gradually become weakened,and basal ganglia-cerebellar FC showed increased,which driven cerebellum-thalamic-cortical loop activation to compensate.Parkinson's disease subtypes showed different FC pattern,which eventually lead to differences in clinical manifestation and treatment.