The Research Of The Structural Changes Of Brain Tissue In Different Motor Subtypes Of Parkinson's Disease Based On Diffusion Kurtosis Imaging

Objective: Using magnetic resonance diffusion kurtosis imaging(Diffusion kurtosis imaging,DKI)to study the microstructure of substantia nigra and basal ganglia in patients with Parkinson's disease(PD).The purpose of this study was to determine whether the microstructural changes of deep brain nucleus were different between tremor subtype(TD)and postural instability gait disorder subtype(PIGD),and to explore the value of this functional imaging technique in the diagnosis and differentiation of different phenotypes of PD.Methods: A total of 61 clinically diagnosed PD patients and 56 healthy controls(HC)were included in this study.According to the(UPDRS)related score of the unified Parkinson's disease assessment scale,the patients with PD were divided into tremor(TD)(n = 29)and unstable gait disorder(PIGD)(n = 32).All subjects underwent 3.0T GE diffusion kurtosis imaging(DKI).Demographic data such as sex,age and education level of all subjects were collected and recorded,and a comprehensive neurological examination was performed in all PD patients.Hoehn-Yahr stage(H ? Y stage),Parkinson's disease unified score scale part III(UPDRS-?),simple mental state scale(MMSE),Montreal Cognitive scale(Mo CA)was used to evaluate the severity of motor symptoms and the degree of cognitive impairment.After the original DKI image was processed by software,the average dispersion kurtosis(MK)diagram,the average dispersion rate(MD)diagram and the anisotropic fractional(FA)diagram were obtained.MK,MD and FA values of bilateral substantia nigra,red nucleus,putamen,globus pallidus,caudate nucleus head and thalamus were measured.Univariate analysis of variance(ANOVA)and Post-Hoc t test were used to compare the difference of DKI parameters among TD group,PIGD group and HC group,and the correlation between DKI parameters and course of disease and clinical scale score in PD group was analyzed.The diagnostic efficiency of DKI parameters for PD and the ability to distinguish different motor subtypes of PD were analyzed by receiver operating characteristic curve(ROC).Results: Compared with the control group,the MK value of substantia nigra,MK value of globus pallidus,MD value of substantia nigra,MD value of red nucleus,MD value of putamen,MD value of globus pallidus,MD value of caudate nucleus and MD value of thalamus in PD group were significantly higher than those in control group,while FA values of substantia nigra and globus pallidus were decreased.Compared with TD group,the MD value of substantia nigra in PIGD group was significantly higher(P?0.05).There was no significant correlation between DKI and course of disease,UDPRS-score,H?-Y grade,MMSE score,Mo CA score,TD score and PIGD score in PD group.(AUC)analysis of the area under the ROC curve of each nucleus showed that the MK value of substantia nigra was the largest in distinguishing PD from AUC in healthy controls.It was 0.782,followed by substantia nigra MD value,red nucleus MD value,globus pallidus MD value,putamen MD value,caudate nucleus MD value,globus pallidus MK value,thalamus MD value,followed by MD value of substantia nigra,MD value of red nucleus,MD value of globus pallidus,MD value of putamen,MD value of caudate nucleus.Their AUC were 0.768,0.655,0.649,0.638,0.632,0.627 and 0.618,respectively.In addition,ROC curve analysis showed that MD value of substantia nigra could be used to identify TD and PIGD subtypes,and the area under the curve(AUC)was 0.823(p?0.001),the optimum diagnostic threshold was 1.785,and the corresponding sensitivity and specificity were 75% and 78.8%,respectively.Conclusion: 1.DKI is a new magnetic resonance technique for qualitative diagnosis of PD,and DKI parameters can quantitatively evaluate the microstructure of deep gray matter nuclei in PD patients,which has certain application value in the diagnosis of PD.2.the microstructure of substantia nigra and basal ganglia in patients with different motor subtypes of PD was studied by DKI technique.it was found that the difference of DKI parameters between the two types was concentrated in the substantia nigra.Therefore,substantia nigra DKI may be used to distinguish two motor subtypes of Parkinson's disease,which is helpful to better understand the pathophysiological basis of these different phenotypes.