Facets of language performance in early-onset and late-onset Alzheimer’s disease dementia

Abstract

Background: Early-onset Alzheimer's disease dementia (EOAD) is characterized by more pronounced cognitive decline than late-onset AD dementia (LOAD). Characteristic performance in spoken language remains undefined. Method: A cross-sectional analysis of 1,189 people with EOAD and 4,646 with LOAD from the National Alzheimer's Coordinating Center (NACC). Result: Based on data from their first NACC visit with AD, there was considerable heterogeneity in language performance across people with EOAD and LOAD. The distribution of naming ability was similar across these groups. On average, people with LOAD had better performance than people with EOAD for category fluency, letter fluency, and spoken lexical retrieval, and had lower Clinical Dementia Rating (CDR®) language scores, though there was considerable overlap in all of the distributions for people with EOAD and people with LOAD. Discussion: At diagnosis, EOAD and LOAD language profiles are distinct. There is substantial variability in both groups in multiple aspects of language.