Phenotypes and epidemiology of frontotemporal dementia in Iceland

The prevalence of frontotemporal dementia in Iceland is lower than has been reported in some previous studies, incidence comparison is difficult due to difference in age distribution in different studies. Prevalence in the memory clinic population was low, reflecting the rarity of FTD. The average age at diagnosis was higher in Iceland than described in foreign studies and the frequency of memory impairment as an initial symptom was higher compared to foreign studies. Diagnostic methods have developed in recent years and the diagnostic process is more precise than in the earlier years of the study period.