Neuropsychological Differences Related to Age in Dementia with Lewy Bodies

BACKGROUND/AIMS: To examine the influence of age on neuropsychological performances in dementia with Lewy bodies (DLB) and Alzheimer disease (AD) patients. METHODS: We examined memory, executive, and visuo-constructional performances in 202 DLB patients and 236 AD patients. We divided the subjects into three age groups (65–74, 75–84, and 85–95 years old), and evaluated the differences in neuropsychological performances. RESULTS: Recent memory in the DLB group was significantly better than that in the age-matched AD group when comparing the age groups 65–74 years and 75–84 years; however, memory impairment in the DLB patients in the age group 85–95 years was comparable with that in the age-matched AD patients. In contrast to recent memory, the other assessed neuropsychological performances, such as visuospatial and executive functions, showed no significant change in differences between the DLB and AD groups with advancing age. CONCLUSION: Our study revealed that the nature of memory impairment in DLB patients changes according to age. DLB patients in the young-old and old-old age groups showed significantly better memory performance than the age-matched AD patients, whereas memory performance of the DLB patients in the oldest-old age group was similar to that of the age-matched AD patients. This may be associated with the increased rate of coexisting AD pathology in DLB patients with older age.