title: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurology, Institute of Clinical Medicine, University of Oulu, Oulu, Finland ; Department of Neurology, Oulu University Hospital, Oulu, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Luukkainen
authors.affiliation: Medical Informatics Group, University of Oulu, Oulu, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Bloigu
authors.affiliation: Department of Neurology, Oulu University Hospital, Oulu, Finland.
authors.forename: Virpi
authors.initials: V
authors.lastname: Moilanen
authors.affiliation: Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland ; Department of Neurology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Anne Marja
authors.initials: AM
authors.lastname: Remes
keywords: Behavioral variant; Epidemiology; Frontotemporal dementia; Incidence; Prevalence; Progressive nonfluent aphasia; Semantic dementia