Longitudinal motor decline in dementia with Lewy bodies, Parkinson disease dementia, and Alzheimer's dementia in a community autopsy cohort.

Abstract

We examined the progression of extrapyramidal symptoms and signs in autopsy-confirmed dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and Alzheimer's disease dementia (AD). Longitudinal data were obtained from Arizona Study of Aging and Neurodegenerative Disease, with PDD (n=98), AD (n=47) and DLB (n=48) further sub-grouped as with or without parkinsonism (DLB+ and DLB-). Within-group Unified Parkinson's Disease Rating Scale (UPDRS) -II and UPDRS-III trajectories were analyzed using non-linear mixed effects models. In DLB, 65.6% had parkinsonism. Baseline UPDRS-II and III scores (off-stage) were highest (P<0.001) for PDD (mean±SD 14.3±7.8 and 27.4±16.3), followed by DLB+ (6.0±8.8 and 17.2±17.1), DLB- (1.1±1.3 and 3.3±5.5) and AD (3.2±6.1 and 8.2±13.6). Compared to PDD, the DLB+ group had faster UPDRS-III progression over 8-years (Cohen's-d range 0.98 to 2.79, P<0.001), driven by gait (P<0.001) and limb bradykinesia (P=0.02) subscales. Motor deficits progress faster in DLB+ than PDD, providing insights about expected changes in motor function. Dementia with Lewy bodies has faster motor progression than Parkinson's disease dementia Linear and non-linear mixed modeling analysis of longitudinal data was utilized Findings have implications for clinical prognostication and trial design.