Correlations between striatal dopamine transporter distribution, glucose metabolism and clinical symptoms in Parkinson′s disease

Abstract

Objective To investigate the correlations among striatal dopamine transporter (DAT) distribution, glucose metabolism and Parkinson′s disease (PD) clinical symptoms. Methods Twenty-five clinically confirmed idiopathic PD patients (17 males, 8 females, age: (59.8±9.2) years) who underwent 11C-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane (CFT) and 18F-fluorodeoxyglucose (FDG) PET imaging from January 2015 to December 2016 were reviewed. The detailed clinical scores were systematically collected from all patients. Correlations between DAT distribution, glucose metabolism and clinical symptoms were evaluated at global and voxel levels using Pearson correlation analysis. Results There were significantly positive correlations between the PD-related pattern (PDRP) value and unified PD rating scale (UPDRS) motor scores, non-motor symptoms scale (NMSS) scores, activity of daily living scale (ADL) scores (r values: 0.580, 0.522, 0.557, all P 0.05). The CFT uptake of ipsilateral caudate nucleus and anterior putamen were negatively correlated with ADL scores (r values: -0.502, -0.522, both P 0.05). The presence of the significant correlations between UPDRS motor scores, ADL scores and the CFT radioactive count were confirmed in left caudate nucleus and left putamen (r values: from -0.90 to -0.47, all P<0.05). The metabolic PET imaging disclosed a set of brain regions correlating with the clinical symptoms. The presence of significant correlations between the metabolic PET imaging and CFT uptake were confirmed in bilateral caudate nucleus (r values: 0.47-0.90, both P<0.01), precentral gyrus and insula (r values: -0.90 to -0.47, all P<0.01). Conclusion The correlations between DAT distribution, glucose metabolism and PD clinical symptoms are complicated, which promote the understanding in the proper application of dopaminergic and metabolic PET imaging in PD and offer more evidences in PD pathophysiological mechanisms. Key words: Parkinson disease; Dopamine plasma membrane transport proteins; Signs and symptoms; Positron-emission computed; Deoxyglucose