Movement disordersProgressive supranuclear palsy and corticobasal degeneration: Diagnostic challenges and clinicopathological considerations

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are two atypical parkinsonian syndromes first described half a century ago. The spectrum of these conditions as well as, more generally, the concept of tauopathy have dramatically changed over the past decade and especially in recent years. In particular, clinicopathological correlations have led to the description of several subtypes of these diseases and the features they share with other neurodegenerative diseases. The present paper is a review of how the concepts of PSP and CBD have evolved over time. In particular, it focuses on the different presentations of the disease and the overlapping syndromes that can complicate the differential diagnoses. Also discussed are some of the tools that may prove useful in making a diagnosis. Indeed, differential diagnosis issues are of particular importance in light of the likely emergence of pathology-specific disease-modifying therapies in the near future.