Epidemiology of Frontotemporal Lobar Degeneration in Northern Finland

Abstract

Background: Frontotemporal lobar degeneration (FTLD) is responsible for as many as every fifth case of early-onset dementia. Very few epidemiological studies of FTLD have been conducted; there are no published epidemiological data of FTLD from Finland or the other Nordic countries. The C9ORF72 expansion-associated FTLD is common in Finland; thus, the prevalence of FTLD is expected to be high in this population. Methods: We retrospectively evaluated the incidence and prevalence of FTLD in university hospital settings in Northern Finland. Results: The mean 1-year incidence of FTLD was 5.54/100,000 (range 1.9-11.3/100,000) in the population aged 45-65 years. The prevalence of FTLD in the same age group was 20.5/100,000. Conclusion: The incidence and prevalence of FTLD in Finland seem to be the highest in Europe. However, studies from different countries may not be directly mutually comparable due to methodological issues.

Keywords

• Frontotemporal dementia
• Progressive nonfluent aphasia
• Epidemiology
• Semantic dementia
• Incidence
• Behavioral variant
• Prevalence