2009 Volume 49 Issue 6 Pages 335-341
The aim of this study is to investigate the frequency, causes, and clinical characteristics of individuals with presenile dementia with an age of onset less than 65 years. A staged questionnaire survey was performed among all hospitals and clinics, all faculties of care and welfare services, and all local governmental offices in Aichi prefecture. The response rate of the primary survey was 62.3%, and that of the secondary survey was 90.1%. The number of people with presenile dementia after adjusting for duplicated subjects was 1,092 (569 men, 520 women and 3 of unknown gender). The average age was 60.7±7.1 (mean±SD) years, and age of onset was 55.1±7.8 years. Vascular dementia (VD) was the most frequent cause in men (42.2%), followed by Alzheimer's disease (AD: 24.8%), frontotemporal dementia (FTD: 4.6%) and Parkinson disease (PD: 3.8%). In women, AD was the most common (45.8%), followed by VD (25.4%), FTD (7.4%) and PD (3.4%). Overall, AD and VD were the most common causes of presenile dementia, followed by FTD and PD. The highest prevalence of presenile dementia was seen in the age range of 60-64 years old. This was true for both men and women.
