Screening for Alzheimer's disease in low-educated or illiterate older adults in Brazil: a systematic review

Diagnosis of Alzheimer’s disease: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT This paper presents the consensus of the Scientific Department of Cognitive Neurology and Aging from the Brazilian Academy of Neurology on the diagnostic criteria for Alzheimer’s disease (AD) in Brazil. The authors conducted a literature review regarding clinical and research criteria for AD diagnosis and proposed protocols for use at primary, secondary, and tertiary care levels. Within this clinical scenario, the diagnostic criteria for typical and atypical AD are presented as well as clinical, cognitive, and functional assessment tools and complementary propaedeutics with laboratory and neuroimaging tests. The use of biomarkers is also discussed for both clinical diagnosis (in specific conditions) and research.

Diagnosis of Alzheimer's disease: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

This paper presents the consensus of the Scientific Department of Cognitive Neurology and Aging from the Brazilian Academy of Neurology on the diagnostic criteria for Alzheimer's disease (AD) in Brazil. The authors conducted a literature review regarding clinical and research criteria for AD diagnosis and proposed protocols for use at primary, secondary, and tertiary care levels. Within this clinical scenario, the diagnostic criteria for typical and atypical AD are presented as well as clinical, cognitive, and functional assessment tools and complementary propaedeutics with laboratory and neuroimaging tests. The use of biomarkers is also discussed for both clinical diagnosis (in specific conditions) and research.

Identifying Appropriate Neuropsychological Tests for Uneducated/Illiterate Older Individuals

OBJECTIVES

We investigated the utility of traditional neuropsychological tests in older uneducated/illiterate individuals without dementia to determine the possibility that they are likely not appropriate for this group.

METHODS

We assessed the neuropsychological performance of 1122 older adults [≥65 years old; mean age: 74.03 (SD = 5.46); mean education: 4.76 (SD = 2.5) years; women: n = 714], in the context of the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD), a population-based study conducted in Greece.

RESULTS

We based our analyses on three groups: high-functioning/cognitively healthy (i.e., without dementia) uneducated/illiterate individuals (n = 80), high-functioning/cognitively healthy educated/literate individuals (n = 932), and low-functioning/cognitively impaired educated/literate individuals (presumably with dementia; n = 110). We used binary regression analyses with Bonferroni correction to investigate whether test performance differentiated uneducated/illiterate from educated/literate individuals. Models were adjusted for age and sex; raw test scores were the predictor variables. The uneducated/illiterate cohort was at a disadvantage relative to the healthy educated/literate group on all variables but verbal memory recognition and consolidation, congruent motor responses, and phonological fluency clustering (p > .002). Moreover, only word list learning immediate and delayed free recall and delayed cued recall differentiated the high-functioning/cognitively healthy uneducated/illiterate from the low-functioning/cognitively impaired educated/literate group, favoring the former (p's < .002).

CONCLUSIONS

Our findings suggest that only particular verbal memory test variables are fair in determining whether older uneducated/illiterate individuals have functional/cognitive impairment suggestive of a neurodegenerative process. On all other neuropsychological variables, this cohort was at a disadvantage. Therefore, we highlight the need for identifying appropriate methods of assessment for older uneducated/illiterate individuals.

Association between baseline Mini-Mental State Examination score and dementia incidence in a cohort of oldest old

BACKGROUND

The Brazilian population has aged rapidly. The oldest old, defined as persons aged 80 years or older, is the fastest growing segment of the Brazilian population. Several instruments have been used to assess the cognitive performance of the older people and predict dementia. One of the most commonly used is the Mini-Mental State Examination (MMSE).

OBJECTIVE

The aim of this study was to investigate the relationship between baseline MMSE score and the incidence of dementia in a Brazilian cohort of independent oldest old.

METHODS

Sociodemographic data and serial cognitive assessment of 248 older adults were analyzed.

RESULTS

Mean follow-up time of subjects was 4.0(±1.9) years, 71.4% were women, and mean MMSE score at entry was 25(±3.5). Mean MMSE scores at baseline were significantly higher (p=0.001) in the cognitively intact group than in those who developed dementia. The logistic regression showed that for a one point increase in MMSE score at baseline there was a 10% reduction in the probability of dementia.

CONCLUSIONS

In the Brazilian scenario of a rapidly growing population of oldest old, the extensive use of the MMSE gives rise to the need not only to determine its effectiveness for screening dementia, but also to interpret its score in terms of future conversion to dementia.

Diagnostic Accuracy of Usual Cognitive Screening Tests Versus Appropriate Tests for Lower Education to Identify Alzheimer Disease

INTRODUCTION

The accuracy of commonly used screening tests for Alzheimer's disease (AD) has not been directly compared to those that could be more appropriate for lower schooling.

OBJECTIVE

To compare the diagnostic accuracy of usual screening tests for AD with instruments that might be more appropriate for lower schooling among older adults with low or no literacy.

METHODS

The study included a clinical sample of 117 elderly outpatients from a Geriatric Clinic classified as literate controls (n = 39), illiterate controls (n = 30), literate AD (n = 30) and illiterate AD (n = 18). The tests were compared as follows: Black and White versus Colored Figure Memory Test; Clock Drawing Test versus Clock Reading Test; Verbal Fluency (VF) animal versus grocery category; CERAD Constructional Praxis versus Stick Design Test.

RESULTS

The means of literate and illiterate controls did not differ in the Black and White Figure Memory Test (immediate recall), Colored Figure Memory Test (delayed recall), Clock Reading Test and VF animals and grocery categories. The means of the clinical groups (controls versus AD), in the 2 schooling levels, differed significantly in most of the tests, except for the CERAD Constructive Praxis and the Stick Design Test. Diagnostic accuracy was not significantly different between the compared tests.

CONCLUSION

Commonly used screening tests for AD were as accurate as those expected to overcome the education bias in a sample of older adults with lower or no education.

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

Mild cognitive impairment (MCI) is a widely studied concept that has changed over time. Epidemiology, diagnosis, costs, prognostics, screening procedures, and categorization have been extensively discussed. However, unified guidelines are still not available, especially considering differences between low- and middle-income countries (LMIC) and high-income countries (HIC).

Neuroimaging Research on Dementia in Brazil in the Last Decade: Scientometric Analysis, Challenges, and Peculiarities

The last years have evinced a remarkable growth in neuroimaging studies around the world. All these studies have contributed to a better understanding of the cerebral outcomes of dementia, even in the earliest phases. In low- and middle-income countries, studies involving structural and functional neuroimaging are challenging due to low investments and heterogeneous populations. Outstanding the importance of diagnosing mild cognitive impairment and dementia, the purpose of this paper is to offer an overview of neuroimaging dementia research in Brazil. The review includes a brief scientometric analysis of quantitative information about the development of this field over the past 10 years. Besides, discusses some peculiarities and challenges that have limited neuroimaging dementia research in this big and heterogeneous country of Latin America. We systematically reviewed existing neuroimaging literature with Brazilian authors that presented outcomes related to a dementia syndrome, published from 2010 to 2020. Briefly, the main neuroimaging methods used were morphometrics, followed by fMRI, and DTI. The major diseases analyzed were Alzheimer's disease, mild cognitive impairment, and vascular dementia, respectively. Moreover, research activity in Brazil has been restricted almost entirely to a few centers in the Southeast region, and funding could be the main driver for publications. There was relative stability concerning the number of publications per year, the citation impact has historically been below the world average, and the author's gender inequalities are not relevant in this specific field. Neuroimaging research in Brazil is far from being developed and widespread across the country. Fortunately, increasingly collaborations with foreign partnerships contribute to the impact of Brazil's domestic research. Although the challenges, neuroimaging researches performed in the native population regarding regional peculiarities and adversities are of pivotal importance.

Geriatric syndromes in an urban elderly population in Cameroon: a focus on disability, sarcopenia and cognitive impairment

Introduction

geriatric syndromes are multifactorial conditions that are associated with substantial disability, poor quality of life and mortality in the elderly. The patterns of these conditions are poorly described in sub-Saharan Africa. This study aimed to determine the prevalence and correlates of common geriatric syndromes in Cameroon.

Methods

we conducted a cross-sectional study in the geriatrics unit of a university hospital in Cameroon. All people aged ≥55 who attended a health promotion and screening campaign in September 2019 were included. Geriatric syndromes including functional decline, cognitive impairment and sarcopenia were assessed. We also examined sociodemographic characteristics and comorbidities.

Results

overall, 104 participants were enrolled with median age of 65 (IQR: 62.2 - 70.8). About 67% of participants presented at least one geriatric syndrome. Disability in activities of daily living and instrumental activities of daily living were present in 10% and 38% of participants respectively and associated factors were male gender (OR 4.7, p=0.005), age 75 and above (OR 5.7, p=0.027), osteoarthritis (OR 3.3, p=0.055) and polypharmacy (OR 7.7, p=0.012). Sarcopenia occurs in 26% with female gender (OR 3.1, p=0.029) and SARC-F ≥4 (OR 4.9, p=0.002) as associated factors. Cognitive impairment was present in 20% of participants and associated with illiteracy (p=0.008).

Conclusion

our study shows a high prevalence of geriatric syndromes in older adults in an urban area. Geriatric principles and frailty awareness should be considered in clinical care of older adults in our setting.

Systematic Review of the Diagnostic Validity of Brief Cognitive Screenings for Early Dementia Detection in Spanish-Speaking Adults in Latin America

Objectives: The aim of this study was to evaluate the validity of brief cognitive screening (BCS) tools designed to diagnose mild cognitive impairment (MCI) or dementia in Spanish-speaking individuals over the age of 50 years from Latin America (LA).

Methods: A systematic search of titles and abstracts in Medline, Biomed Central, Embase, Scopus, Scirus, PsycINFO, LILACS, and SciELO was conducted. Inclusion criteria were papers written in English or Spanish involving samples from Spanish-speaking Latin American individuals published until 2018. Standard procedures were applied for reviewing the literature. The data related to the study sample, methodology, and procedures applied, as well as the performance obtained with the corresponding BCS, were collected and systematized.

Results: Thirteen of 211 articles met the inclusion criteria. The studies primarily involved memory clinic-based samples, with the exception of two studies from an adult day-care center, one from a primary care clinic, and one from a community-based sample. All the studies originated from five of the 20 countries of LA and all used standardized diagnostic criteria for the diagnosis of dementia and MCI; however, the diagnostic protocols applied differed. Most studies reported samples with an average of 10 years of education and only one reported a sample with an average of <5 years of education. No publication to date has included an illiterate population. Although the Montreal cognitive assessment (MoCA) is the most widely-used BCS tool in LA, it is significantly influenced by education level.

Conclusions: Although evidence is still limited, the findings from studies on LA populations suggest that MoCA requires cultural adaptations and different cutoff points according to education level. Moreover, the diagnostic validity of the INECO frontal screening (IFS) test should be evaluated in populations with a low level of education. Given the heterogeneity that exists in the levels of education in LA, more studies involving illiterate and indigenous populations are required.