Some of the sporadic disorders (progressive supranuclear palsy [PSP] and corticobasal degeneration) have been referred to by molecular pathologists as primary tauopathies, implicating abnormalities of tau in their pathogenesis.
Further immunohistochemical and biochemical studies revealed that AgD is a four-repeat (4R) tauopathy similar to PSP and corticobasal degeneration (CBD), but distinct from Alzheimer's disease (AD) and Pick's disease.
We enrolled 34 de novo PD patients and 29 patients affected by atypical parkinsonisms (Multiple System Atrophy, MSA, n = 10; Progressive Supranuclear Palsy, PSP, n = 12 and Corticobasal Degeneration, CBD, n = 7) who underwent an acute levodopa challenge.