Validation of the movement disorder society criteria for the diagnosis of 4-repeat tauopathies

The Movement Disorder Society criteria for progressive supranuclear palsy introduced the category 'probable 4-repeat (4R)-tauopathy' for joint clinical diagnosis of progressive supranuclear palsy and corticobasal degeneration.To validate the accuracy of these clinical criteria for 'probable 4R-tauopathy' to predict underlying 4R-tauopathy pathology.Diagnostic accuracy for 4R-tauopathies according to the established criteria was estimated retrospectively in autopsy-confirmed patients with progressive supranuclear palsy and corticobasal degeneration (grouped as 4R-tauopathies), and Parkinson's disease, multiple system atrophy, and frontotemporal lobar degeneration (grouped as non-4R-tauopathies).We identified 250 cases with progressive supranuclear palsy (N = 195) and corticobasal degeneration (N = 55) and with and non-4R-tauopathies (N = 161). Sensitivity and specificity of 'probable 4R-tauopathy' was 10% and 99% in the first year and 59% and 88% at final record.The new diagnostic category 'probable 4R-tauopathy' showed high specificity and may be suitable for the recruitment of patients with progressive supranuclear palsy and corticobasal degeneration into therapeutic trials targeting 4R-tauopathy. The low sensitivity underpins the need for diagnostic biomarkers. © 2019 International Parkinson and Movement Disorder Society.