Progressive supranuclear palsy (PSP) has historically been studied primarily in Western populations, but increasing research from non-Western countries has revealed important variations in epidemiology, genetics, clinical presentation, and healthcare access. This page synthesizes evidence from Asian, African, Latin American, and other non-Western populations, highlighting both shared features and population-specific findings that inform our understanding of PSP globally[1].
Japan has conducted some of the most comprehensive epidemiological studies on PSP in Asia. Population-based studies from Japan report a prevalence of 4-6 per 100,000, somewhat lower than Western estimates of 5-7 per 100,000.
Key Japanese studies have revealed:
Recent Japanese research has also focused on the H1 haplotype frequency in the Japanese population, finding similar associations with PSP risk but with different sub-haplotype patterns compared to European populations[2].
Chinese epidemiological studies have provided crucial data on PSP in East Asia. Hospital-based studies suggest a prevalence of 2-5 per 100,000, though community-based studies are limited[3].
Notable findings from Chinese research:
The Chinese population has shown unique MAPT haplotype patterns, with the H1c subhaplotype showing stronger association with PSP than in European populations[2:1].
Korean studies have documented PSP epidemiology with findings similar to other East Asian populations. A national health insurance database analysis revealed increasing diagnosis rates over time, suggesting improved recognition[4].
Key Korean findings:
India represents a significant population with limited but growing PSP research. Hospital-based studies from major neurology centers in India have documented clinical characteristics[5].
Indian epidemiological considerations:
Genetic studies in Indian populations have identified shared MAPT risk alleles with European populations, but also novel variants that require further investigation.
Research on PSP in Sub-Saharan Africa remains extremely limited, representing a significant gap in global understanding[6].
Available evidence suggests:
The lack of data from Sub-Saharan Africa represents a critical gap in understanding PSP globally. Factors contributing to this gap include:
Latin American countries have contributed increasingly to PSP research, with studies from Brazil, Argentina, and other countries.
Brazilian studies represent the most extensive Latin American research on PSP. Studies from the Federal University of São Paulo and other centers have documented clinical characteristics[7].
Brazilian findings:
Argentine research has contributed to understanding PSP in South America. Studies from Buenos Aires have documented clinical and demographic characteristics[8].
Notable findings:
Latin American research highlights important healthcare disparities:
The MAPT H1 haplotype is the strongest genetic risk factor for PSP, but its structure varies across populations[2:2].
Population-specific findings:
Population-specific rare variants have been identified:
While core clinical features are consistent across populations, some variations have been noted:
| Feature | Western | East Asian | South Asian | Latin America |
|---|---|---|---|---|
| Mean age of onset | 63-65 years | 66-70 years | 62-67 years | 64-67 years |
| Male ratio | 1.3-1.5:1 | 1.2-1.4:1 | 1.3:1 | 1.4:1 |
| PSP-RS frequency | 50-60% | 40-50% | 45-55% | 50-55% |
| PSP-P frequency | 25-30% | 30-35% | 25-30% | 25-30% |
| Early falls | 70% | 65% | 70% | 65% |
Non-Western populations face significant diagnostic challenges:
Therapeutic access disparities are substantial:
Clinical trial participation shows marked disparities:
Global research initiatives should prioritize:
PSP epidemiology in Asian populations. Movement Disorders. 2023. ↩︎
MAPT genetic variation in Asian PSP patients. Neurology. 2022. ↩︎ ↩︎ ↩︎
Chinese PSP epidemiology. Parkinsonism and Related Disorders. 2023. ↩︎
Korean PSP epidemiology. Journal of Neurology. 2023. ↩︎
Indian PSP clinical characteristics. Annals of Indian Academy of Neurology. 2021. ↩︎
PSP in African populations. Neurology Africa. 2022. ↩︎
Brazilian PSP epidemiology. Arquivos de Neuro-Psiquiatria. 2022. ↩︎
Argentine PSP clinical features. Movement Disorders Clinical Practice. 2021. ↩︎