FDG PET in Movement Disorders and Parkinsonian Syndromes.

FDG PET is a powerful adjunct for the differential diagnosis of parkinsonian syndromes because it reveals disease specific regional and network level metabolic signatures. Compared with dopamine transporter imaging, it better distinguishes Parkinson disease from progressive supranuclear palsy, corticobasal degeneration or corticobasal syndrome, multiple system atrophy, and Lewy body dementia such as Parkinson disease dementia and dementia with Lewy bodies. When combined with expert clinical assessment and multimodal imaging, FDG PET substantially improves diagnostic confidence, especially in early or atypical presentations.