To describe the clinical phenotypes, gender and ethnic background of patients with progressive supranuclear palsy (PSP) enrolled in a PSP clinical-research program.

The Rossy-PSP Program is a specialized clinic created in 2019 with the mission of embedding research in care of patients with PSP. It includes comprehensive multimodal data collection in a population with a diverse ethnical background from Toronto, Ontario, Canada and its surrounding areas. 

A longitudinal, observational study of patients presenting with atypical parkinsonism and/or cognitive impairments through application of the MDS-PSP criteria. Follow-up every 6 months with collection of demographical and clinical data.

Between October 2019 and October 2021, 110 patients were screened. Criteria for clinical PSP fulfilled by 91 patients: mean age 71±7.4 years; 38% female; mean duration 5 years, mean age-of-onset 66.8±7 years. Of them, 50 were of European ancestry, 17 from countries of southern Asia and Middle East, 11 from east Asia, 7 from countries of the West Indies Islands, 5 from Africa, and 1 from South America. Richardson syndrome was the most common initial presentation, followed by corticobasal syndrome and PSP-Parkinsonism (Table 1). The non-Richardson syndrome phenotypes ranged between 28% (Caucasian) to 37% (east Asia) and 40% (southern Asia).

This baseline data highlights the ethnic diversity and sex differences in patients with PSP and the distribution of non-Richardson presentation at onset. Awareness of PSP variants among diverse populations can increase diagnosis at earlier stages of disease and assist in epidemiological research and studies to develop reliable diagnostic and representative biomarkers.