Neuropsychological differentiation of dementia with Lewy bodies from normal aging and Alzheimer's disease

We examined the diagnostic utility of selected neuropsychological measures in the differentiation of dementia with Lewy bodies (DLB) from normal aging and Alzheimer's disease (AD). Patients with DLB (n = 87), AD (n = 138), and a group of normal controls (n = 103) were recruited from the Mayo Alzheimer's disease patient registry and Alzheimer's Disease Research Center. Neuropsychological measures shown to have utility in previous studies were included in the analysis. The final multivariate logistic regression model distinguishing DLB from normal controls included Auditory Verbal Learning Test (AVLT) percent retention, Block Design, Trail Making Test - Part A, and Benton Visual Form Discrimination. This model has a sensitivity of 88.6% and specificity of 96.1%. The final multivariate logistic model distinguishing DLB from AD included Trail Making Part A, Boston Naming Test (BNT), AVLT percent retention, and copy of the Rey-Osterrieth Complex Figure. This model had a sensitivity of 83.3% and a specificity of 91.4%. AVLT and BNT had negative coefficients, indicating that lower scores decreased the likelihood of DLB relative to AD. These finding extend prior research suggesting a cognitive profile that can aid in the clinical diagnosis of DLB. Early attention and visual perceptual disturbance suggests DLB, while early impairment in memory and naming suggests AD.