“…In that regard, FPCIT PET provides complementary information concerning the evolution of dopaminergic de cits in iRBD and the relationship of these changes to the onset of parkinsonism 23 . While presynaptic dopaminergic de cits, particularly those localized to the putamen, are a recognized risk factor for phenoconversion 12,24 , these measurements, as well as other potential predictors such as severity of motor symptoms, autonomic dysfunction, and cerebrospinal uid analysis, do not accurately foretell subsequent transition to clinically manifest PD 25,26 . That said, the longitudinal PET data presented in this study suggest that changes in PDRP expression and putamen DAT binding, when evaluated together, may predict phenoconversion more accurately than either measure alone.…”