Dopamine transporter imaging in progressive supranuclear palsy: Severe but nonspecific to subtypes.

Background: Previous studies with a limited sample size suggested more severe dopaminergic transporter (DAT) lesions in the striatum of progressive supranuclear palsy (PSP) than those in Parkinson's disease (PD) and multiple system atrophy-parkinsonism (MSA-P). However, few studies had taken various subtypes of PSP into consideration, making the reanalysis of DAT imaging in larger PSP cohort with various subtypes in need.

Objectives: To compare the dopaminergic lesion patterns of PSP with MSA-P and PD, and to explore the specific striatal subregional patterns of different PSP subtypes.

Methods: C-CFT positron emission tomography (PET) imaging was conducted in 83 PSP patients consisting of different subtypes, 61 patients with PD, 41 patients with MSA-P, and 43 healthy volunteers. Demographic and clinical data were compared by the chi-squared test or one-way analysis of variance. A generalized linear model was used to examine intergroup differences in tracer uptake values after adjusting for age, disease duration, and disease severity. Areas under the receiver operating characteristic curve were calculated to assess the diagnostic accuracy of subregional DAT binding patterns.

Results: The patients with PSP presented more severe DAT loss in the striatum than in PD and MSA-P, especially in caudate. In PSP, the subregional lesion was still more severe in putamen than in caudate, similar to that in PD and MSA-P. Among detailed subtypes, no significant difference was detected.

Conclusion: The dopaminergic lesions were more severe in PSP, and no difference was detected among subtypes.