DEMENTIA WITH LEWY BODIES IS ASSOCIATED WITH GREATER DEPENDENCE: AN AUTOPSY STUDY

Abstract

Dependence has been linked to caregiver burden and cost of care in dementia. However, dependence levels have not been well described in Dementia with Lewy bodies (DLB). To address this issue, we analyzed and compared dependence data as well as cognitive, motor, and neuropsychiatric data from a cohort of autopsy-confirmed cases of DLB and Alzheimer's disease (AD). The sample was derived from the Predictors Study, a multicenter cohort study of patients with probable AD or DLB. The current study includes 42 patients who underwent autopsy and met pathologic criteria for AD (12 subjects) or DLB (9 pure DLB and 12 DLB plus AD). At the baseline visit, the Dependence Scale was administered to measure the amount of assistance required by patients, yielding a dependence level, ranging from 0 (totally independent) to 5 (totally dependent). The dependence level, cognitive function (measured by Mini–Mental State Examination, MMSE) and non-cognitive symptoms were compared between groups using ANOVA. Regression models were used to evaluate the association between pathology groups and dependence level. The average (SD) dependence level at baseline evaluation was 2.47 (1.39) and 3.33 (1.09), respectively, for the 21 autopsy-confirmed AD and 21 DLB patients (p = 0.044). There was no statistically significant difference (p = 0.17in baseline MMSE between the two groups: DLB mean (SD) = 19 (5.3), AD mean (SD) = 21 (3.6). A higher percentage of DLB patients than AD patients presented with extrapyramidal signs (70.6% vs. 20.0%, p = 0.002) and delusions (63.2% vs. 25%, p = 0.016). Compared to AD patients, DLB patients had a 0.95 (p = 0.025) higher dependence level after adjusting for age, sex, and education. The association remained significant (b = 0.86, p = 0.044) after additional adjustment for MMSE. To our knowledge, this is the first study to use an autopsy-confirmed cohort to compare dependence levels between DLB and AD. DLB patients had statistically significantly greater dependence level than AD patients even after adjusting for age, sex, education, and MMSE. The wide spectrum of cognitive and non-cognitive symptoms observed in DLB likely impacts dependence and thus may affect the level of care and cost associated with this disorder.