This Article Full Text Full Text (PDF) All Versions of this Article: 40/8/2709    most recent STROKEAHA.108.542308v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Ikejima, C. Articles by Asada, T. PubMed PubMed Citation Articles by Ikejima, C. Articles by Asada, T. Pubmed/NCBI databases Medline Plus Health Information Dementia Related Collections Behavioral Changes and Stroke Epidemiology

(Stroke. 2009;40:2709.)
© 2009 American Heart Association, Inc.

Original Contributions

Prevalence and Causes of Early-Onset Dementia in Japan

A Population-Based Study

Chiaki Ikejima, MS; Fumihiko Yasuno, MD, PhD; Katsuyoshi Mizukami, MD, PhD; Megumi Sasaki, MD; Satoshi Tanimukai, MD, PhD Takashi Asada, MD, PhD

From the Department of Neuropsychiatry (C.I., F.Y., K.M., M.S., T.A.), Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan; and the Department of Neuropsychiatry, Neuroscience (S.T.), Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, Japan.

Correspondence to Takashi Asada, MD, PhD, Department of Neuropsychiatry, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan. E-mail tasada{at}md.tsukuba.ac.jp

Background and Purpose— Few studies are available that have addressed the prevalence of early-onset dementia (EOD), including early-onset Alzheimer disease and other forms of dementia in Japan.

Methods— A 2-step postal survey was sent to all of the 2475 institutions providing medical or care services for individuals with dementia in Japan’s Ibaraki prefecture (population, 2 966 000) requesting information on EOD cases. Data were then reviewed and collated.

Results— We identified 617 subjects with EOD. The estimated prevalence of EOD in the target population was 42.3 per 100 000 (95% CI, 39.4 to 45.4). Of the illnesses that cause EOD, vascular dementia was the most frequent (42.5%) followed by Alzheimer disease (25.6%), head trauma (7.1%), dementia with Lewy bodies/Parkinson disease with dementia (6.2%), frontotemporal lobar degeneration (2.6%), and other causes (16.0%).

Conclusions— The prevalence of EOD in Japan appeared to be similar to that in Western countries with the notable exception that vascular dementia was the most frequent cause of EOD in Japan.

Key Words: early-onset dementia • prevalence • vascular dementia