O1-03-05: Survival and mortality differences between dementia with lewy bodies versus Alzheimer disease

Abstract

Dementia with Lewy bodies (DLB) is a common cause of dementia after Alzheimer disease (AD). Clinical progression of AD is well characterized; however the clinical progression of DLB has not fully been elucidated. There are conflicting reports in the literature regarding disease progression. To determine whether DLB progresses more rapidly than AD to relevant clinical endpoints such as nursing home placement and death. We compared 315 participants (63 DLB and 252 AD) enrolled in a prospective longitudinal study of memory and aging with annual clinical and cognitive assessments and followed until death. The main outcome measure was dementia progression to institutionalization and death. Neuropathologic examinations were performed on all participants in this study. Subject classification (DLB vs. AD) was based on neuropathology. Patients with DLB had an increased risk of mortality vs. patients with AD (HR 1.88, 95% CI: 1.4–2.5). The median survival time for DLB was 78.0y and for AD was 84.6y (χ2=19.9, p<.001) with significant modification effects due to gender (HR 1.51, 95% CI: 1.0–2.3) and the presence of at least 1 ApoE e4 allele (HR 1.50, 95% CI: 1.0–2.2). Survival after dementia onset was also different between DLB and AD (7.3y vs. 8.5y, χ2=5.4, p<.02). DLB cases had similar risks of institutionalization and survival in long term care facilities to AD cases. Self reports of depression and the presence of extrapyramidal signs were important covariates. The rate of cognitive decline as measured by psychometric performance and clinical staging methods did not differ between DLB and AD. Dementia with Lewy bodies increases the risk of mortality compared with AD but the two groups did not differ in rate of cognitive decline. The greater risk for non-cognitive disease progression for DLB compared with AD suggests clinically meaningful differences for the two disorders.