Neuropsychological Evaluation Of Narrative Discourse Patterns In Individuals With Early Stage Vascular Dementia Vs. Patients With Early Stage Alzheimer'S Disease

Background Individuals in the early stages of dementia may demonstrate language difficulties. The aim of the study was an evaluation of the differences in narrative discourse abilities across two types of dementia, i.e., Vascular Dementia (VaD) and Alzheimer's Disease (AD) in comparison to the young and old elderly.Material/Methods: Four groups included patients presenting an early stage of VaD (N=14), an early stage of AD (N=14), a young control elderly - YE (N=19), and an old control elderly - OE (N=29) were set up. Neuropsychological testing examined the verbal and nonverbal functions classified into the following cognitive domains: verbal memory, executive functions, reasoning, attention/working memory. Narrations were elicited with two tasks of story retelling and were analyzed on the micro-, macro-, and super-structure level of discourse organization.Results: The AD and VaD groups displayed a lower performance than the age-matched YE on tasks involving reasoning. The VaD participants outperformed patients with AD in verbal memory and narrative discourse. Discourse macrostructure analyses showed that the VaD reproduced more propositions than did the AD participants, but that these were comparable to YE and OE. There were more conjunctions in narratives reproduced by the VaD participants as compared to other groups, although this tendency was only present in the story but not in fairy tale reproductions themselves. Individuals in the AD group had more difficulties than YE and OE individuals in figuring out the moral of fairy tales. Clinical and control groups reproduced the microstructure and superstructure of texts comparatively well. Discourse recall correlated with performance on verbal memory, attention/working memory, and reasoning.Conclusions: Differences in narrative discourse abilities were found. Alzheimer's Disease (AD) patients scored lower in verbal memory than did Vascular Dementia (VaD) patients. Both groups however obtained lower results than the young and old elderly.