Language in Amnestic Mild Cognitive Impairment and Dementia of Alzheimer’s Type: Quantitatively or Qualitatively Different?

Abstract

Background/Aims: The purpose of this study was to explore language differences between individuals diagnosed with amnestic mild cognitive impairment multiple domain (aMCIm) and those with probable Alzheimer’s disease, with a goal of (i) characterizing the language profile of aMCIm and (ii) determining whether the profiles of dementia of Alzheimer’s type (DAT) and aMCIm individuals are on a continuum of one diagnostic entity or represent two distinct ­cognitive disorders. Methods: Language data from 28 patients with consensus diagnosis of aMCIm and DAT derived from a retrospective chart review were compared to that of healthy controls. Results: A non-parametric statistic established that there was no significant difference between groups in age, years of education or duration of symptoms and that expressive language was found to be relatively intact in both patient groups. In contrast, both groups exhibited significant impairments on receptive language tests and on linguistically complex tasks that rely on episodic memory and executive functions. Individuals with aMCIm and DAT present with configurations of language features that are largely in parallel to each other and reflect predominantly quantitative differences. Conclusion: Language tests provide an important contribution to the diagnostic process in their capacity to identify language impairments at an early stage. Understanding the nature of language decline is critically important to the intervention process as this information would inform cognitive intervention approaches aimed at promoting quality of life in people living with MCI and dementia.

The Diagnostic Value of Language Screening in Primary Progressive Aphasia: Validation and Application of the Sydney Language Battery

“…Even though Naming and Semantic Association scores were significantly lower in the AD group compared to the MCI group, MCI patients performed significantly lower than cognitively unimpaired controls. This confirms increasing evidence that language deficits begin several years before the onset of AD dementia (Auriacombe et al, 2006) and that differences in language features between AD and MCI reflect predominantly quantitative instead of qualitative differences (Jokel et al, 2019). Earlier studies (Alexopoulos et al, 2006) have shown that individuals with multidomain MCI, including language deficits, are more likely to develop AD than those with an isolated memory deficit.…”

Laptop-Administered NIH Toolbox and Cogstate Brief Battery in Community-Dwelling Black Adults: Unexpected Pattern of Cognitive Performance between MCI and Healthy Controls

“…Differences in measures of reading ability and vocabulary skills have been shown between individuals with MCI and HC previously. For example, individuals with MCI perform worse than HC on the Peabody Picture Vocabulary Test, a paper-pencil test which is similar to the PV task administered in the NIHTB-CB (Jokel, Seixas Lima, Fernandez, & Murphy, 2019). Although such vocabulary skills are thought to generally remain stable across the lifespan and represent estimated premorbid cognitive functioning (i.e., crystallized abilities), there is also evidence that performance on the Peabody Picture Vocabulary Test declines with increasing cognitive deficit, such as when comparing individuals with MCI to those with AD (Snitz, Bieliauskas, Crossland, Basso, & Roper, 2000) and could reflect changes in language functioning.…”

Sentence comprehension in ageing and Alzheimer's disease

“…It may be hypothesised, then, that serious reductions in the capacity of WM cause the deficits summarised above, which include impaired interpretation of non‐canonical sentence structures and potential length effects. This is one of the most commonly cited explanations and one for which ample evidence exists (Jokel et al., 2019). Following this hypothesis, language impairments in AD can be seen as a more severe type of the declines often observed in typical ageing, though exacerbated by a reduced inhibitory control faculty and a highly impaired attention span (Ober and Shenaut, 1988).…”

“…Language ability and a severe deterioration thereof is one of the earliest and clearest markers of the onset of AD. Patients developing AD generally show an increasing inability to name familiar objects or people, reflecting the rapid deterioration of semantic memory associated with the condition (Jokel et al., 2019). Problems with pronunciation also develop due to increasing difficulties with swallowing and tongue movements, caused by an underlying motor impairment (Moorhouse & Fisher, 2017).…”