Early detection of cognitive disturbances in mild cognitive impairment: a systematic review of observational studies

Abstract

Mild cognitive impairment (MCI) is an intermediate state between normal cognition and early dementia and is not considered as a typical outcome of brain aging. It has been estimated that 10% to 20% of individuals above 65 years of age will be diagnosed as having MCI. The increased rate of dementia and the importance of early detection of its forerunners have encouraged researchers to focus on detecting MCI and modifiable risk factors with the hope of developing better ways of managing dementia and its consequences. The main aim of this study was to systematically review the related literature concerning the cognitive changes in the spectrum of cognitive aging to cognitive impairment. Articles included in this review were identified through searching the databases of PubMed, Psych Info, Embase, ProQuest, and Scopus. Many domains like verbal memory, language, executive function, visual memory, attentional skills, and working memory showed acceptable predictive power. Testing subdomains such as executive function, speed of processing, working memory and semantic language are critical and others may indicate some suggestions for further clinical deteriorations in normal individuals. Although various cognitive instruments have been used for evaluation of impaired cognitive domains, it remains challenging to select the most appropriate ones having high‐level accuracy and their related cognitive subdomains. It also revealed that none of the identified cognitive domains solely fulfilled the criteria for MCI screening; in clinical settings, multiple neuropsychological batteries may be used for one single cognitive domain, while longitudinal studies prefer the use of at least two cognitive measures for each domain to improve accuracy and research settings might focus on only a single neuropsychological test. However, along with episodic memory, testing for amnestic MCI, executive function could increase the chance of early detection of MCI. Executive control has been found to deteriorate the earliest in MCI patients.

Psychometric Properties of the Persian Montreal Cognitive Assessment in Mild Cognitive Impairment and Alzheimer Disease

“…In addition to being strongly correlated with the overall MMSE score, the MoCA showed a good internal consistency, with a Cronbach α of 0.74, like in previous studies [15-19]. In the current investigation, a significant statistical difference in the performance on the MoCA was found between cognitively healthy individuals, patients with MCI, and patients with mild AD, compatible with other studies [6, 15, 20, 21].…”

“…Our results indicate, in line with previous studies [6, 22, 23], that the Persian version of the MoCA has a high validity for detecting individuals with AD. This result is consistent with the recognized benefits of the MoCA in detection of the early stages of cognitive impairment [18-20, 24], suggesting that the MoCA is a more adequate tool for detection of MCI in the Iranian population. These findings are in consensus with studies from other countries that have revealed that, compared with the MMSE, the MoCA is more sensitive in detecting MCI in different settings and conditions [18, 22, 24].…”

The effect of a psychomotor intervention on electroencephalography and neuropsychological performances in older adults with and without mild cognitive impairment

“…Mild cognitive impairment (MCI) refers to a transient cognitive state between normal ageing and dementia. MCI is a risk state for Alzheimer's disease (AD) and a common cause of dementia, but MCI is not necessarily leading to AD or other forms of dementia 1,2 . To delay the onset of AD and other forms of dementia, new approaches for precisely identifying the (pre)clinical stages of MCI and effectively treating it are a global health and health‐care priority.…”

Palm Fruit Bioactive Complex (PFBc), a Source of Polyphenols, Demonstrates Potential Benefits for Inflammaging and Related Cognitive Function

“…It states that there must be both a subjective and objective decline in one or more of the six cognitive domains, not substantially interfering with instrumental activities of daily living, and not occurring in the context of delirium or other psychological disorders [6,7]. MCI occurs along a continuum from normal cognition to dementia and while not all individuals with MCI progress to AD, MCI alone can decrease quality of life and increase risk of other negative health outcomes [8]. Incidence has been reported to range from a low of 3% to a high of 22% in individuals over 65 years of age [9].…”