Neuroimaging features in progressive supranuclear palsy and corticobasal degeneration

Progressive supranuclear palsy (PSP) and cortocobasal degeneration (CBD) are often clinically confused with each other. In this paper, based our previous and on-going morphological and functional neuroimaging studies, the features characteristic of the two diseases are discussed. In PSP patients, the atrophic and metabolic changes are dominant in the frontal lobes, basal ganglia, and midbrain, while in CBD patients, the changes are dominant in the parietal lobe. There is little overlap of topographical distribution of atrophy and functional changes between PSP and CBD, despite the considerable similarity of symptoms of the two disorders. The clear distinction between the two diseases may be in part caused by the criteria-based subject selection process: based on stringent clinical diagnostic criteria for each disorder, which have a high specificity and a low sensitivity, only patients that are typical of each disease are compared. Nevertheless, these neuroimaging features appear to reflect different clinical and pathologic phenotypes between the two diseases. These findings suggest that neuroimagings facilitate the differential diagnosis between patients with PSP and those with CBD.