A – 10 Early Visual Spatial Predictors in Alzheimer's Disease and Dementia with Lewy bodies

Abstract Objective Visual-spatial deficits are early cognitive indicators of progression in Alzheimer's Disease (AD) and dementia with Lewy bodies (DLB). The Benson Complex Figure Task (BCFT) assesses visual perception, construction and memory abilities. We examined BCFT performance in mild cognitive impairment (MCI) patients who later progressed to either AD (MCI-AD) or DLB (MCI-DLB), with the aim of assessing its potential as a predictor of disease progression. Method Data from the National Alzheimer Coordinating Center dataset was reduced from 50,259 to 3,522 participants to include only those individuals converting from MCI-AD (n=793) or MCI-DLB (n=59), had at least two visits, and had both BCFT copy and recall scores. Exclusion criteria included individuals who never had a MCI diagnosis. Two logistic regressions with bootstrapped standard errors were conducted, controlling for age and education, to examine progression to AD or DLB. Results Copy scores below the clinical cutoff were associated with higher likelihood of conversation to DLB vs. AD (B = 0.79, OR = 2.21, BCa CI [0.26, 1.36], p = .005). Recall scores below the clinical cutoff were associated with lower likelihood of conversation to DLB vs. AD (B = -.64 OR = 0.53, BCa CI [-1,17, -0.10], p < .05). Conclusion Worse performance on the copy condition was associated with conversion to DLB, whereas worse performance on the recall condition was associated with conversion to AD. Differential performance on the copy and recall conditions of the BCFT may be a useful metric when distinguishing between progression to AD or DLB.