Ching-Kuan Liu
Chi-Ta Tai
Ruey-Tay Lin
Chiou-Lian Lai
Department of Neurology Kaohsiung Medical University
Owing to the rapidly increased population of the aged people in Taiwan, the dementia patients who are prevalent in aged people also increase rapidly. The prevalence of dementia among the elderly(aged 65 and over) is around 2-4% in Taiwan, which is lower than those in developed countries. The reason for this low prevalence may result from relatively young elderly people in Taiwan compared to those of developed countries; high mortality among the demented patients; under-estimation due to the difficulty in diagnosis; and ethnic difference, such as low frequency of apolipoprotein E4 among Taiwanese. In prevalence, Alzheimer’s disease(AD) is the leading cause of dementia, and account for about 50%, followed by Vascular dementia(VaD) (20-25%), and mixed AD and VaD(MIX)(5-10%). The incidence of dementia among the elderly in Taiwan is around 13 per thousand person-years(PTPY). The most common cause of new incident dementia cases is AD(around 40-50%), followed by VaD (30-35%), and MIX(15%). The relative increase of VaD and MIX in incidence compared to that in prevalence may result from very high mortality among VaD and MIX. Overall, the 2-year mortality rate was high among the demented(48% in total dementia, 38% in AD, 60% in VaD, and 70% in MIX). The risk factors for AD were increased age, female sex, low education(illiteracy), apolipoprotein E4, and history of major head injury. The risk factors for VaD were stroke and hypertension. The community survey showed that many families of dementia patients were not yet prepared to understand dementia, and therefore did not bring the patients to seek for medical management. As various types of dementia render specific treatment, early and differential diagnosis becomes more and more important. The campaign for public education in dementia deserves more effort.
Keywords: dementia, epidemiology, Alzheimer’s disease, Vascular dementia