Incidence of Progressive Supranuclear Palsy
The incidence of progressive supranuclear palsy (PSP) is approximately 5.3 per 100,000 person-years in individuals aged 50-99 years, with incidence increasing steeply with age and consistently higher rates in men. 1
Age-Specific Incidence Rates
The incidence of PSP demonstrates a marked age-dependent pattern:
- Ages 50-59 years: 1.7 per 100,000 person-years 1
- Ages 80-99 years: 14.7 per 100,000 person-years 1
- No cases occur before age 50 years 1
The steep rise in incidence with advancing age means PSP predominantly affects the elderly population, with mean age of onset approximately 63 years. 2
Sex Distribution
- Men are consistently affected at higher rates than women across all age groups 1
- The male predominance is a consistent epidemiological feature of PSP 2
Prevalence Estimates
While the question asks about incidence, understanding prevalence provides additional context:
- Crude population prevalence ranges from 1.39 to 4.9 per 100,000 3
- More recent US insurance database analysis found age-adjusted prevalence of 2.95 per 100,000 in 2016 4
- European estimates suggest prevalence around 5 per 100,000 5
The lower prevalence estimate from the 2016 US database may reflect underdiagnosis or coding issues rather than true lower disease frequency. 4
Clinical Context and Survival
Understanding incidence must be contextualized with disease progression:
- Mean survival from symptom onset is 5.3 to 9 years 1, 2
- The relatively short survival time means prevalence remains low despite ongoing incidence 1
- Median survival of 5-8 years is consistently reported across studies 5
Diagnostic Considerations Affecting Incidence Reporting
Typical PSP symptoms often present before formal diagnosis, indicating potential delays in recognition that may underestimate true incidence: 4
- Gait abnormalities appear in 79.3% of patients before diagnosis 4
- Parkinson's disease is coded in 54.6% before PSP diagnosis, suggesting initial misdiagnosis 4
- Falls and ophthalmoplegia may not present until late in illness 2
The heterogeneous clinical presentation and overlap with other parkinsonian syndromes means reported incidence figures likely represent minimum estimates. 2, 5