Diagnostic accuracy of early cognitive indicators in mild cognitive impairment

Abstract

The aging of the population leads to an increase in the prevalence of dementia and mild cognitive impairment (MCI). Alzheimer's disease (AD) is the most common cause of dementia. Recent studies highlight the early non-amnestic deficits in AD and MCI. The European Union report shows the importance of thoroughly assessing cognitive aspects that have been poorly evaluated, such as processing speed (PS), which could represent early indicators of cognitive decline. Objective: To analyze the diagnostic accuracy of PS measures in older adults with MCI, AD, and those who are cognitively-healthy. Methods: A cross-sectional study was conducted by performing an extensive neuropsychological assessment in three samples: 26 control participants, 22 individuals with MCI, and 21 individuals with AD. Analysis of variance (ANOVA) was employed to test the relationship between dependent variables and the clinical group. Post hoc tests (Bonferroni test) were used when a significant ANOVA result was found. Finally, the Receiver Operating Characteristic (ROC) curve for PS measures was performed in older adults with MCI and AD compared with cognitively-healthy older adults. Results: The results showed that deficits in PS measures can be early indicators of cognitive decline in cases of MCI, even when executive functions (EFs) and functionality are preserved. Conversely, AD versus MCI presented differences in PS, EFs, and functionality. Conclusions: The ROC analyses showed that PS measures had discriminative capacities to differentiate individuals with MCI, AD, and cognitively-healthy older adults.

Diagnostic accuracy of CompCog: reaction time as a screening measure for mild cognitive impairment

“…There is also evidence of a correlation between reductions in processing speed and general cognitive performance. 18 It is interesting to note that a reduction in processing speed is also related to subjective memory complaints 43 . Although this kind of complaint usually does not involve an objective deficit in standard tests, it is possible that patients somehow already perceive their slower reaction time.…”

“…For a long time, processing speed has been seen as a fundamental aspect of cognition and an essential aspect of healthy aging 17 . Studies have shown that it declines through many neurodegenerative conditions 13,15,16,[18][19][20] . One metanalysis found slower reaction time among MCI patients than among healthily aging individuals 21 .…”

Mild cognitive impairment history and current procedures in low- and middle-income countries: a brief review

“… 25 , 30 Analyses comparing medical diagnosis to the assessment of processing speed measures reached similar results. 31 Therefore, there is still room for discussion on how to detect MCI, especially considering its heterogeneity and considering the different contexts seen in LMIC and HIC.…”

“…In the latter, neuropsychological assessment is a more accessible course of action, 12 even in the initial stages. 31 Activities of daily living scales are already used in clinical contexts, but a closer look at errors and their awareness could suggest the onset of a pathological process in the very beginning and be a useful approach to MCI screening.…”

Evidence of the validity of a novel version of the computerized cognitive screening battery CompCog

“…But to keep up with the technological advances of healthcare and cognitive neuroscience, in general, more efforts must be made in the field of clinical neuropsychology to develop and validate new and more technology-based instruments considering variables known to be valuable and that technology made it possible to use such as processing speed and reaction time. 17 The paper and pencil neuropsychological tests hardly have precise reaction time measurements, but this is an advantage that stands out among computerized tests: specific and complex variables, such as reaction time, can be measured even in milliseconds. 18 Reaction time is a variable that seems to be affected throughout many types of neurodegenerative conditions, 19 - 22 and the present computerized battery focuses on the reaction time as its primary measure — although it is also able to measure errors.…”