Prevalence and Causes of Early-Onset Dementia in Japan

Abstract

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.

Younger Onset Dementia

“…25 The accuracy of these estimates is debatable, given the international differences that have been reported. 19 Awareness of YOD may have changed in recent years, with improvements in neuroimaging technology and diagnostic procedures that may influence the identification of cases with dementia. [27][28][29] The Australian Institute of Health and Welfare (AIHW) report 7 used United Kingdom estimates 17,18 for the under-60 age-group but data from a more recent meta-analysis 25 for the other age-groups.…”

The Restoration After Repetitive Transcranial Magnetic Stimulation Treatment on Cognitive Ability of Vascular Dementia Rats and Its Impacts on Synaptic Plasticity in Hippocampal CA1 Area

“…It was reported that VaD was the first cause of senile dementia in Asian countries (Roman 2002;Zhang et al 2005;Ikejima et al 2009). The molecular mechanism of VaD onset is still not clear, and therapeutics related to its molecular mechanism has also been developed continuously in recent years.…”

Epidemiology of dementia in Asia: Insights on prevalence, trends and novel risk factors

“…In China, VaD is more common than AD in rural compared to urban areas [35]. Given the rapid pace of development in China, it is not surprising that the most recent Chinese prevalence study showed an AD prevalence of 3.5% compared to 1.1% for VaD in those aged more than 65 years [14]. These patterns are repeated across Asian countries as shown in Tables 1a-1c.…”

“…Hence, the low prevalence of VaD in some studies could be attributed to limited use of neuroimaging. Identification of subtypes of dementia without neuroimaging in China reported that 29% of demented patients had VaD [14] compared to a higher VaD diagnosis rate of 47% among patients who underwent brain computed tomography (CT) in Japan [10].…”