Vascular dementia in Japan

Abstract

Patients with vascular dementia are frequently encountered in Japan reaching nearly 50% of those with senile dementia, which is equal to or even slightly higher than patients with Alzheimer's disease. This contrasts with a much lower ratio of patients with vascular dementia in the United States. The majority of vascular dementia seen in Japan is of the multiple lacunar type or Binswanger disease, often without any episode of stroke. Clinically, those patients tend to have attention deficit and reduction of spontaneous activities. The observed characteristics of vascular dementia likely reflect the main type of cerebrovascular disease prevalent in Japan since the majority of cerebral infarction in Japan is of lacunar type in contrast to that in the United States and Europe. For patients without any episode of stroke, it is important to differentiate from Alzheimer's disease. As in the United States and Europe, mixed dementia exists in Japan with Alzheimer's disease and vascular dementia together and poses problems in clinical diagnosis because many patients may not have any episode of stroke, but they have neuroimaging characteristics compatible with both. The number of patients with atherosclerosis in large cervical and cerebral arteries is said to be increasing in Japan, and vascular dementia in Japan may present with different clinical pictures in the future.