Syndromic approach to Parkinson's disease: role of functional imaging

Current evidence from monogenic Parkinson's disease (PD) supports the view that PD is a clinical syndrome, rather than a single disease entity, and that the heterogeneity of PD indeed reflects different pathogenesis. Recent developments in functional imaging have enabled the in vivo assessment of cellular and molecular pathology of PD with respect to temporal and topographical patterns. We propose that this new technology will be useful for linking monogenic and sporadic PD, and thus, for classifying PD based on the pathogenesis. It will be also useful in clinico-genetic studies exploring susceptibility factors and at-risk groups, which are important for neuroprotective treatment when it becomes available.