Past Issues

Objectives: The frequency of dementia subtypes in Taiwan need to be resurveyed in light of the increased awareness and recognition of non-Alzheimer type dementias. Early- and late-onset dementias have not been compared among Taiwanese patients with dementia. Methods: All patients participating in the Lin- Shin dementia registry project were required to complete a structured interview form every six months to record their basic data, clinical history, neuropsychological tests, sleep quality, and neuropsychiatric symptoms. In the current study, basic demographic characteristics of participants were summarized, and subtypes of dementia were compared between early- and late-onset patients. Results: From February 1, 2009 to January 31, 2011, a total of 968 patients was investigated; 795 patients fulfi lled the criteria for dementia and 173 patients were not demented. Among all the patients under study (n = 795), Alzheimer’s disease (AD, n = 378, 47.5%) was the most prevalent cause of dementia, followed by vascular dementia (VaD, n = 151, 19.0%), Dementia with Lewy bodies (DLB, n = 132, 16.6%), Parkinson’s disease with dementia (PDD, n = 64, 8.1%), frontotemporal lobar degeneration (FTLD, n = 33, 4.2%), normal pressure hydrocephalus (NPH, n = 11, 1.4%), and other dementia/undetermined dementia (OD/UD, n = 26, 3.3%). More than 60 percent of FTLD patients were early onset (< 65 years); on the other hand, more than 80 percent of AD, VaD, DLB, PDD, and NPH were late onset (≥ 65 years). Conclusion: The frequency of AD, DLB, PDD, VaD in our subjects are similar to the fi ndings in several Western countries; but the frequency of DLB is higher than most of the recent clinical studies in Asian countries. The results of this study remind clinicians of paying attention to the high frequency of non-AD degenerative dementias and to the potential difference of treatment among patients with AD and non-AD dementias.