Biomarkers of Alzheimer disease in mild cognitive impairment: Experience in a memory clinic from Latin America

Abstract Background. The population of Latin America and the Caribbean (LAC) is ageing rapidly, presenting the highest prevalence rates of dementia in the world. In this context, mild cognitive impairment (MCI) is an intermediate condition between normal ageing and dementia. However, very few studies verified the prevalence of MCI in LAC countries; earlier global systematic reviews only considered prevalence reports published in English language. Method. We conducted a systematic review to evaluate the prevalence of MCI in LAC countries and to explore the factors associated with MCI (i.e., age, gender, and education). A database search was conducted in February 2020 using PubMed, Web of Science, Scopus, Lilacs, SciELO, and EMBASE, for population-or community-based studies with MCI data for countries in LAC, published in English, Spanish, or Portuguese language. From k=2,168 identified and k=1,684 screened studies, only articles were selected that included subjects with a precise diagnosis of MCI. The studies were qualitatively assessed using the JBI critical appraisal checklist for studies reporting prevalence data tool. Results. A total of nine studies met the criteria, published between 2007 and 2019, including a total of 17,812 participants in nine countries Brazil, Mexico, Argentina, Colombia, Peru, Cuba, Dominican Republic, Venezuela, and Costa Rica. Estimates for MCI prevalence ranged from 1.2% to 34%, with most estimates between 1.2% and 6.45%. Estimates differed by age group, gender, and educational level. Discussion. This is the first systematic review of the prevalence of MCI in LAC countries, considering only high-quality studies adopting rigorous diagnostic criteria.

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

Dementia and Geriatric Cognitive Disorders Extra ◽

10.1159/000514673 ◽

2021 ◽

pp. 51-57

Author(s):

Vahid Rashedi ◽

Mahshid Foroughan ◽

Negin Chehrehnegar

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Alzheimer Disease ◽

Psychometric Properties ◽

Cognitive Assessment ◽

Screening Test ◽

Cognitive Status ◽

Montreal Cognitive Assessment ◽

Cutoff Score ◽

Persian Version

Introduction: The Montreal Cognitive Assessment (MoCA) is a cognitive screening test widely used in clinical practice and suited for the detection of Mild Cognitive Impairment (MCI). The aims were to evaluate the psychometric properties of the Persian MoCA as a screening test for mild cognitive dysfunction in Iranian older adults and to assess its accuracy as a screening test for MCI and mild Alzheimer disease (AD). Method: One hundred twenty elderly with a mean age of 73.52 ± 7.46 years participated in this study. Twenty-one subjects had mild AD (MMSE score ≤21), 40 had MCI, and 59 were cognitively healthy controls. All the participants were administered the Mini-Mental State Examination (MMSE) to evaluate their general cognitive status. Also, a battery of comprehensive neuropsychological assessments was administered. Results: The mean score on the Persian version of the MoCA and the MMSE were 19.32 and 25.62 for MCI and 13.71 and 22.14 for AD patients, respectively. Using an optimal cutoff score of 22 the MoCA test detected 86% of MCI subjects, whereas the MMSE with a cutoff score of 26 detected 72% of MCI subjects. In AD patients with a cutoff score of 20, the MoCA had a sensitivity of 94% whereas the MMSE detected 61%. The specificity of the MoCA was 70% and 90% for MCI and AD, respectively. Discussion: The results of this study show that the Persian version of the MoCA is a reliable screening tool for detection of MCI and early stage AD. The MoCA is more sensitive than the MMSE in screening for cognitive impairment, proving it to be superior to MMSE in detecting MCI and mild AD.

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