Dural Tracer Study Of Bilateral-Onset Parkinson'S Disease Phenotype

1572 Purpose: Parkinson’s disease (PD) is a neurodegenerative disorder which is characterized by asymmetric movement syndrome. We also found several patients with bilateral-onset syndrome which has been validated by follow-up. In this work, we characterized cerebral glucose metabolism associated with different onset clinical syndrome in Parkinson’s disease (PD) using18 F-fluorodeoxyglucose (FDG) and dopamine transporter (DAT) Positron Emission Tomography (PET). Methods: Two PD cohorts were recruited in this study including PD patients with bilateral-onset (PD-B; n = 20) and with lateral-onset (PD-L; n = 45, with left side predominant syndrome). Two PD cohorts were matched for age, sex, duration (less than 3 years), UPDRS-III score and Hoehn and Yahr stage. An age-matched normal cohort was also recruited (NC; n = 20). All subjects underwent FDG-PET and DAT-PET study. Maps of regional metabolism and SUVR of DAT in the three groups were compared using statistical parametric mapping (SPM8) and scanvp software. Results: Both PD-B and PD-L cohorts exhibited areas of hypometabolism in the parietal and occipital lobes and areas of hypermetabolism in frontal, temporal and cerebellum compared with the NC cohort (p< 0.001). Furthermore, PD-B patients had areas of hypermetabolism in the right temporal, left parietal lobe and bilateral limibic lobe compared with PD-L cohort (p< 0.001), and exhibited limited metabolic reductions in left middle frontal gyrus and inferior parietal lobule (p< 0.001). From DAT PET analysis, we calculated the asymmetric index of 11C-CFT uptake, defined as (absolute value of bilateral SUVR difference / absolute value of bilateral SUVR average). And we found the asymmetric index of both anterior and posterior putamen were significantly different between PD-B and PD-L cohorts (p<0.005). Conclusions: Compared with NC cohort, both PD-B and PD-L showed similar hypometabolism and hypermetabolism areas. There were limited difference of metabolism and dopamine depletion between 2 patient cohorts, which might suggest the bilateral onset patients were another subtype of PD phenotype.