Progressive Supranuclear Palsy-A Global Review

Progressive Supranuclear Palsy (PSP) is a rare and severe neurodegenerative tauopathy characterized by diverse clinical phenotypes, including Richardson's syndrome (PSP-RS), PSP-parkinsonism (PSP-P), PSP-progressive gait freezing (PSP-PGF), and PSP-corticobasal syndrome (PSP-CBS). Significant geographic variation exists in prevalence, clinical presentations, and prognosis.

This global review aims to systematically evaluate the epidemiological variation, clinical phenotypes, diagnostic practices, and management strategies for PSP, focusing on regional disparities and identifying influencing genetic and environmental factors.

A comprehensive literature search following PRISMA guidelines was conducted, analyzing studies reporting PSP epidemiology, phenotypes, diagnostic criteria, risk factors, treatments, and prognoses. Data were categorized into epidemiology, risk factors, clinical presentations, diagnosis, treatment accessibility, and outcomes, considering geographic variation.

Global PSP prevalence ranges between 5-6.4 per 100,000, influenced by diagnostic criteria and healthcare infrastructure. Clinical manifestations commonly include supranuclear gaze palsy, frequent falls, cognitive impairment, and motor dysfunction. Prognosis significantly varies with subtype; PSP-RS shows rapid progression and shorter survival (5-7 years), whereas PSP-P has a milder clinical course (8-12 years). Regional variations highlight differences in genetic predispositions, notably the MAPT H1 haplotype, environmental risk factors such as dietary neurotoxins and industrial pollutants, and accessibility to comprehensive healthcare services. Diagnostic accuracy has improved with the adoption of MDS-PSP criteria, facilitating recognition of diverse phenotypes.

Regional disparities in PSP prevalence, phenotypic presentation, and healthcare accessibility underscore the importance of standardized diagnostic criteria, targeted genetic and environmental studies, and equitable healthcare strategies. Enhanced global collaboration is essential for improving PSP diagnosis, management, and patient outcomes worldwide.