Cognitive and Functional Profiles in Mild-to-Moderate Alzheimer’s Disease and Mild Cognitive Impairment Compared to Healthy Elderly

Background: Amnestic mild cognitive impairment (aMCI) and mild-to-moderate Alzheimer’s disease (AD) are clinically distinct but impact cognitive and functional ability similarly. Comprehensive assessment of cognitive and functional deficits may prove useful in informing differential diagnosis in early stages of dementia and in informing endpoint selection in therapeutic AD trials. Objective: The objective of this study was to characterize patterns of cognitive and functional impairment in aMCI and mild-to-moderate AD subjects compared to cognitively intact healthy elderly (HE). Methods: Thirty-one healthy elderly, 20 aMCI and 19 AD participants were administered a cognitive test battery that included the ADAS-Cog and functional assessments. Z-scores were calculated for all endpoints based on the HE reference group. Results: Cognitive deficits were observed in AD and aMCI participants relative to the referent group. On average, aMCI participants performed 1 2 standard deviations below HE on cognitive tests, and AD participants performed 2 3 standard deviations below HE. Domain-specific functional deficits among AD participants (zscore −0.4 to −6.4) were consistently greater than those of aMCI participants (z-score 0 to −1.7). Conclusion: This study provides further support for comprehensive assessment and monitoring of Corresponding author.