Multicenter population‐based study on the prevalence of early onset dementia in Japan: Vascular dementia as its prominent cause

Abstract

Aim:In Japan, the government and media have become aware of the issues of early onset dementia (EOD), but policies for EOD have not yet been established and support systems are inadequate. To provide practical data about EOD, a two-step postal survey was performed.Methods: A questionnaire requesting information on EOD cases was sent to target institutions in five catchment areas in Japan. According to the answers from the institutions, we estimated the prevalence of EOD using census data and determined the illnesses causing EOD. As a quality control study, the authors reviewed every diagnosis in a quarter of the reported cases using the medical and psychiatric records and neuroimaging data. This study was conducted from 2006 to 2007. Results:Information from 2469 patients was collected from 12 747 institutions, and 2059 subjects with EOD were identified. The estimated prevalence of EOD was 47.6 per 100 000 (95% confidence interval, 47.1-48.1) for all of Japan. Of the illnesses causing EOD, vascular dementia (VaD) was the most frequent (39.8%), followed by Alzheimer's disease. Conclusions:The prevalence of EOD in Japan appeared to be similar to that in Western countries. However, unlike previously reported international experience, VaD was the most frequent cause of EOD in all catchment areas in Japan.

Relationship between dementia severity and behavioural and psychological symptoms in early‐onset Alzheimer's disease

“…All underwent structural neuroimaging with magnetic resonance imaging of the brain and routine laboratory tests. In addition to these 63 hospital outpatients, we included 29 EOAD patients from our community‐based survey on the prevalence of early onset dementia . This study was conducted in the same catchment area as our university hospital in 2008.…”

“…In addition to these 63 hospital outpatients, we included 29 EOAD patients from our community-based survey on the prevalence of early onset dementia. 21 This study was conducted in the same catchment area as our university hospital in 2008. We visited these EOAD patients at home, in the hospital, or in the nursing home and examined them using the same procedure as used on the outpatients.…”

Diabetes mellitus and risk of early‐onset Alzheimer's disease: a population‐based case–control study

“…EOD results in severe impact on employment, social functioning, financial status and family relationships, thereby reducing patient quality of life. Alzheimer's disease (AD) and vascular dementia are the most common causes of EOD . In our previous study involving patients with AD, it was revealed that the proportion of patients with early‐onset AD was approximately 3% amongst all patients in the study population .…”

“…Dementia affects 47.5 million people worldwide, with 7.7 million new cases emerging each year . The prevalence of dementia in patients aged <65 years, typically defined as early‐onset dementia (EOD), has recently been reported as between 48 and 172 per 100 000 individuals . EOD results in severe impact on employment, social functioning, financial status and family relationships, thereby reducing patient quality of life.…”

“…Because the onset of familial AD typically occurs before the age of 40 years , patients aged 40–64 years were included in the study population. Furthermore, as previous studies have indicated that diabetes may exert differential effects on the development of AD in men and women , a subgroup analysis based on sex was also performed.…”