[Abnormalities of white matter differentiate the Parkinson variant of multiple system atrophy from Parkinson's disease].

Objective: To identify objective markers between the Parkinson variant of multiple system atrophy (MSA-P) and Parkinson's disease (PD). Methods: Retrospective analysis was performed on 10 patients with MSA-P, 15 patients with PD, and 15 healthy control group during the period from August 2016 to February 2019 in Baoshan Branch of Shanghai First People's Hospital.We combined the novel tract based spatial statistics (TBSS) and region of interest (ROI) analyses for the first time to investigate three groups with diffusion tensor imaging. By TBSS, we performed pairwise comparisons of mean diffusivity and fractional anisotropy (FA) maps. The clusters with significant differences between MSA-P and PD were used as ROIs for further analyses. Results: FA values in the left anterior thalamic radiation(ATR) (ROI values were 0.371(0.287-0.535), 0.472(0.390-0.594), 0.473(0.388-0.555); P values were 0.008, 0.008) and left superior longitudinal fasciculus (SLF)(ROI values were 0.397(0.291-0.469), 0.456(0.338-0.560), 0.473(0.427-0.530); P values were 0.013,<0.001) were significantly decreased in MSA-P compared with PD or controls, and significantly correlated with clinical data((r =-0.807, P =0.005),(r =-0.455, P =0.022)). Conclusion: Our findings indicate the abnormalities of left ATR and left SLF as specific biomarkers for differential diagnosis.