Differences in clinical course between dementia with Lewy bodies and Alzheimer's disease.

Background and purpose:  To investigate whether there may be differences in the clinical course and changes in cognitive progression between dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD). Methods:  We compared the time from the first visit to endpoints (discontinuation of visits because of admission, death, or institutionalization) between 56 patients with DLB and 111 patients with AD. Mini-Mental State Examination (MMSE) scores of patients were every 12 months examined up to 60 months. Results:  Dementia with Lewy bodies had a significantly shorter time to reaching endpoints than those with AD (median time; 40 months vs. 52 months, P < 0.0001). The proportion of admission (or death) was significantly higher in DLB than in AD (30% vs. 14%, P < 0.05), while the difference in institutionalization in nursing homes did not reach statistical significance (25% vs. 17%). Rates of longitudinal MMSE score decline for DLB and AD groups were equivalent. Conclusion:  Dementia with Lewy bodies had a greater risk of admission (or death) because of most commonly fall-related injuries and bronchopneumonia than AD, but the two groups did not differ in rate of cognitive decline.