Biomarkers for dementia in Latin American countries: Gaps and opportunities

Limited knowledge on dementia biomarkers in Latin American and Caribbean (LAC) countries remains a serious barrier. Here, we reported a survey to explore the ongoing work, needs, interests, potential barriers, and opportunities for future studies related to biomarkers. The results show that neuroimaging is the most used biomarker (73%), followed by genetic studies (40%), peripheral fluids biomarkers (31%), and cerebrospinal fluid biomarkers (29%). Regarding barriers in LAC, lack of funding appears to undermine the implementation of biomarkers in clinical or research settings, followed by insufficient infrastructure and training. The survey revealed that despite the above barriers, the region holds a great potential to advance dementia biomarkers research. Considering the unique contributions that LAC could make to this growing field, we highlight the urgent need to expand biomarker research. These insights allowed us to propose an action plan that addresses the recommendations for a biomarker framework recently proposed by regional experts.

High performance older adults in a population-based sample with low education: Pietà study

BACKGROUND

 Healthy brain aging can be defined as aging without neurological or psychiatric disorders, sustaining functional independence. In addition to the absence of disease and preserved functionality, there are individuals who stand out for their superior performance to that considered normal for their age in cognitive tests. These individuals are called "high-performance older adults" (HPOA).

OBJECTIVES

 To investigate the presence of HPOA in an oldest-old population with low education, and if present, to investigate associations with sociodemographic, clinical, and lifestyle variables.

METHODS

 We evaluated 132 cognitively healthy individuals from the Pietà Study, a population-based investigation with 639 participants. We used the delayed recall from the Rey Auditory-Verbal Learning Test to verify the existence of HPOA and to classify participants based on their performance. Sociodemographic, clinical, and lifestyle variables associated with HPOA were investigated.

RESULTS

 We identified 18 individuals fulfilling HPOA criteria (age: 77.4 ± 2.6 years old; 14 women; education: 4.6 ± 3.4 years). The other participants, 114 total (age: 79.8 ± 4.5 years old; 69 women; education: 3.0 ± 2.7 years) were classified as "standard performance older adults" (SPOA). In multivariate analysis, younger age (odds ratio [OR] = 0.672; 95% confidence interval [CI]: 0.462-0.979; p = 0.037) and lower scores on the Geriatric Depression Scale (OR = 0.831; 95%CI: 0.688-0.989; p = 0.038) were associated with HPOA.

CONCLUSIONS

 The present study identifies for the first time HPOA with low educational level, thereby reinforcing the existence of biological substrates related to this condition. Furthermore, the data suggest an association between younger age and less depressive symptoms with HPOA.

Association Between Consumption of Ultraprocessed Foods and Cognitive Decline

Importance

Although consumption of ultraprocessed food has been linked to higher risk of cardiovascular disease, metabolic syndrome, and obesity, little is known about the association of consumption of ultraprocessed foods with cognitive decline.

Objective

To investigate the association between ultraprocessed food consumption and cognitive decline in the Brazilian Longitudinal Study of Adult Health.

Design, Setting, and Participants

This was a multicenter, prospective cohort study with 3 waves, approximately 4 years apart, from 2008 to 2017. Data were analyzed from December 2021 to May 2022. Participants were public servants aged 35 to 74 years old recruited in 6 Brazilian cities. Participants who, at baseline, had incomplete food frequency questionnaire, cognitive, or covariate data were excluded. Participants who reported extreme calorie intake (<600 kcal/day or >6000 kcal/day) and those taking medication that could negatively interfere with cognitive performance were also excluded.

Exposures

Daily ultraprocessed food consumption as a percentage of total energy divided into quartiles.

Main Outcomes and Measures

Changes in cognitive performance over time evaluated by the immediate and delayed word recall, word recognition, phonemic and semantic verbal fluency tests, and Trail-Making Test B version.

Results

A total of 15 105 individuals were recruited and 4330 were excluded, leaving 10 775 participants whose data were analyzed. The mean (SD) age at the baseline was 51.6 (8.9) years, 5880 participants (54.6%) were women, 5723 (53.1%) were White, and 6106 (56.6%) had at least a college degree. During a median (range) follow-up of 8 (6-10) years, individuals with ultraprocessed food consumption above the first quartile showed a 28% faster rate of global cognitive decline (β = -0.004; 95% CI, -0.006 to -0.001; P = .003) and a 25% faster rate of executive function decline (β = -0.003, 95% CI, -0.005 to 0.000; P = .01) compared with those in the first quartile.

Conclusions and Relevance

A higher percentage of daily energy consumption of ultraprocessed foods was associated with cognitive decline among adults from an ethnically diverse sample. These findings support current public health recommendations on limiting ultraprocessed food consumption because of their potential harm to cognitive function.

Resilience of Neural Cellularity to the Influence of Low Educational Level

BACKGROUND

Education is believed to contribute positively to brain structure and function, as well as to cognitive reserve. One of the brain regions most impacted by education is the medial temporal lobe (MTL), a region that houses the hippocampus, which has an important role in learning processes and in consolidation of memories, and is also known to undergo neurogenesis in adulthood. We aimed to investigate the influence of education on the absolute cell numbers of the MTL (comprised by the hippocampal formation, amygdala, and parahippocampal gyrus) of men without cognitive impairment.

METHODS

The Isotropic Fractionator technique was used to allow the anisotropic brain tissue to be transformed into an isotropic suspension of nuclei, and therefore assess the absolute cell composition of the MTL. We dissected twenty-six brains from men aged 47 to 64 years, with either low or high education.

RESULTS

A significant difference between groups was observed in brain mass, but not in MTL mass. No significant difference was found between groups in the number of total cells, number of neurons, and number of non-neuronal cells. Regression analysis showed that the total number of cells, number of neurons, and number of non-neuronal cells in MTL were not affected by education.

CONCLUSIONS

The results indicate a resilience of the absolute cellular composition of the MTL of typical men to low schooling, suggesting that the cellularity of brain regions is not affected by formal education.

Predicting Dementia Due to Alzheimer's Disease and Behavioral Variant Frontotemporal Dementia Using Algorithms with the Addenbrooke's Cognitive Examination-Revised Subscores Combined with Sociodemographic Factors

BACKGROUND

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are important causes of dementia with challenging differential diagnoses in many cases. Addenbrooke's Cognitive Examination-Revised (ACE-R) is a cognitive battery that may be useful to differentiate the two disorders.

OBJECTIVE

The objectibe of this study is to investigate the value of the ACE-R combined with sociodemographic factors in the differential diagnosis between AD and bvFTD.

METHODS

The ACE-R was administered to 102 patients with mild dementia due to probable AD, 37 with mild bvFTD, and 135 controls. Performances of patients and controls were analyzed by logistic regression and by ROC curves to refine the diagnostic accuracy of the ACE-R in AD and bvFTD.

RESULTS

The ACE-R subscores Attention and Orientation, Fluency, and Memory, in combination with schooling differentiated AD from controls with an area under the ROC curve (AUC) of 0.936 (86% sensitivity and 87% specificity). The ACE-R subscores Attention and Orientation, Fluency, and Language, in combination with sex (male), age, and schooling, discriminated bvFTD from controls with an AUC of 0.908 (81% sensitivity and 95% specificity). In the differentiation between AD and bvFTD, the ACE-R subscores Attention and Orientation, Fluency, and Language, together with age, displayed an AUC of 0.865 (78% sensitivity and 85% specificity).

CONCLUSION

The combination of ACE-R scores with sociodemographic data allowed good differentiation between AD and bvFTD in the study sample.

Risk factors for dementia in Brazil: Differences by region and race

INTRODUCTION

Twelve risk factors (RFs) account for 40% of dementia cases worldwide. However, most data for population attributable fractions (PAFs) are from high-income countries (HIC). We estimated how much these RFs account for dementia cases in Brazil, stratifying estimates by race and socioeconomic level.

METHODS

We calculated the prevalence and communalities of 12 RFs using 9412 Brazilian Longitudinal Study of Aging participants, then stratified according to self-reported race and country macro-regions.

RESULTS

The overall weighted PAF was 48.2%. Less education had the largest PAF (7.7%), followed by hypertension (7.6%), and hearing loss (6.8%). PAF was 49.0% and 54.0% in the richest and poorest regions, respectively. PAFs were similar among White and Black individuals (47.8% and 47.2%, respectively) but the importance of the main RF varied by race.

DISCUSSION

Brazil's potential for dementia prevention is higher than in HIC. Education, hypertension, and hearing loss should be priority targets.

Prevalence of dementia in Latin America and Caribbean countries: Systematic review and meta-analyses exploring age, sex, rurality, and education as possible determinants

BACKGROUND

Studies have shown that the prevalence of dementia in Latin America and the Caribbean (LAC) may be higher than in high-income countries. Thus, we sought to systematically analyse the prevalence of dementia and explore possible drivers that lead to this disparity in LAC countries.

METHOD

We searched Pubmed, Web of Knowledge, Scopus, Lilacs, and SciELO for studies on dementia in LAC countries published in English, Spanish, and Portuguese. Random-effects model was applied.

RESULTS

Thirty-one studies from 17 LAC countries were included. Pooled prevalence of all-cause dementia was 10.66%. Further analyses with studies providing raw prevalence by sex, area, and educational level showed a higher prevalence for women (8.97%) than for men (7.26%). Also, dementia prevalence was higher for rural than urban residents (7.71% vs 8.68%, respectively). Participants without formal education presented more than double the prevalence of dementia (21.37%) compared to those with at least one year of formal education (9.88%). Studies with more recent data collection showed higher dementia prevalence.

CONCLUSION

Our findings suggest a high global dementia prevalence in LAC countries and an unequal burden of dementia for women, lower-educated, and rural residents. Secular increases in dementia prevalence call for greater public health efforts for preventative actions.

Does culture shape our understanding of others' thoughts and emotions? An investigation across 12 countries

Measures of social cognition have now become central in neuropsychology, being essential for early and differential diagnoses, follow-up, and rehabilitation in a wide range of conditions. With the scientific world becoming increasingly interconnected, international neuropsychological and medical collaborations are burgeoning to tackle the global challenges that are mental health conditions. These initiatives commonly merge data across a diversity of populations and countries, while ignoring their specificity.

OBJECTIVE

In this context, we aimed to estimate the influence of participants' nationality on social cognition evaluation. This issue is of particular importance as most cognitive tasks are developed in highly specific contexts, not representative of that encountered by the world's population.

METHOD

Through a large international study across 18 sites, neuropsychologists assessed core aspects of social cognition in 587 participants from 12 countries using traditional and widely used tasks.

RESULTS

Age, gender, and education were found to impact measures of mentalizing and emotion recognition. After controlling for these factors, differences between countries accounted for more than 20% of the variance on both measures. Importantly, it was possible to isolate participants' nationality from potential translation issues, which classically constitute a major limitation.

CONCLUSIONS

Overall, these findings highlight the need for important methodological shifts to better represent social cognition in both fundamental research and clinical practice, especially within emerging international networks and consortia. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Diagnóstico da demência frontotemporal: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO A “demência frontotemporal” (DFT) é uma síndrome clínica, cujo denominador comum é o acometimento focal dos lobos frontais e/ou temporais. A DFT tem três fenótipos clínicos distintos: a variante comportamental e dois subtipos linguísticos, a saber, a afasia progressiva primária não-fluente/agramática (APP-NF/A) e a afasia progressiva primária semântica (APP-S). A DFT é a segunda causa mais comum de demência em indivíduos com idade inferior a 65 anos, após a doença de Alzheimer. O presente artigo apresenta recomendações para diagnóstico da DFT no cenário brasileiro, considerando os três níveis de complexidade do sistema de saúde: atenção primária à saúde e níveis secundários. São propostos protocolos de investigação diagnóstica abrangendo testagem cognitiva, avaliação comportamental, avaliação fonoaudiológica, exames laboratoriais e de neuroimagem.

Diagnóstico e manejo da demência da doença de Parkinson e demência com corpos de Lewy: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO A demência da doença de Parkinson (DDP) e a demência com corpos de Lewy (DCL) representam a segunda causa mais comum de demência neurodegenerativa em pessoas com mais de 65 anos, ocasionando progressivo declínio cognitivo e comprometimento da qualidade de vida. O presente estudo tem como objetivo prover um consenso de especialistas sobre a DDP e DCL, baseado em revisão sistemática da literatura brasileira e revisão não-sistemática de literatura internacional. Ademais, tal estudo visa promover informação e conceder recomendações sobre abordagem diagnóstica, com foco nos níveis de atenção primária e secundária em saúde. Com base nos dados disponíveis, recomendamos que os profissionais realizem pelo menos um breve instrumento cognitivo global, como o Mini-Exame do Estado Mental, contudo de preferência optem pela Avaliação Cognitiva de Montreal e o Exame Cognitivo de Addenbrooke-Revisado. Observa-se uma carência de instrumentos validados para a avaliação precisa das habilidades funcionais em pacientes brasileiros com DDP e DCL. Além disso, mais estudos focando em biomarcadores com coortes brasileiras também são necessários.

Management in severe dementia: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT Alzheimer’s disease (AD) and other neurodegenerative dementias have a progressive course, impairing cognition, functional capacity, and behavior. Most studies have focused on AD. Severe dementia is associated with increased age, higher morbidity-mortality, and rising costs of care. It is fundamental to recognize that severe dementia is the longest period of progression, with patients living for many years in this stage. It is the most heterogeneous phase in the process, with different abilities and life expectancies. This practice guideline focuses on severe dementia to improve management and care in this stage of dementia. As it is a long period in the continuum of dementia, clinical practice should consider non-pharmacological and pharmacological approaches. Multidisciplinary interventions (physical therapy, speech therapy, nutrition, nursing, and others) are essential, besides educational and support to caregivers.

Subjective cognitive decline, mild cognitive impairment, and dementia - syndromic approach: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT This consensus, performed by the Brazilian Academy of Neurology (BAN) will approach practically how to evaluate patients with cognitive complaints and how to clinically and etiologically diagnose the three clinical syndromes associated with the different stages of cognitive decline: subjective cognitive decline (SCD), mild cognitive impairment (MCI), and dementia. This BAN consensus discusses SCD diagnosis for the first time, updates MCI and dementia diagnoses, recommends the adequate cognitive tests and the relevant etiological work-up and care of patients with cognitive decline at different levels of care within the Brazilian Unified Health System. We also review the main assessment instruments used in Brazil and Latin America.

Declínio cognitivo subjetivo, comprometimento cognitivo leve e demência - diagnóstico sindrômico: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO Este consenso realizado pela Academia Brasileira de Neurologia (ABN) abordará de maneira prática como avaliar pacientes com queixas cognitivas e como realizar o diagnóstico clínico e etiológico das três síndromes clínicas associadas aos estágios de declínio cognitivo: declínio cognitivo subjetivo (DCS), comprometimento cognitivo leve (CCL) e demência. O diagnóstico de DCS é discutido pela primeira vez em consenso da ABN e as atualizações para o diagnóstico de CCL e demência são abordadas, bem como a recomendação para o uso de testes cognitivos apropriados, investigação etiológica pertinente e cuidados aos pacientes com declínio cognitivo nos diferentes níveis de atenção do Sistema Único de Saúde. Foi realizada pesquisa dos principais instrumentos de avaliação utilizados em nosso meio e na América Latina.

Diagnosis of vascular cognitive impairment: recommendations of the scientific department of cognitive neurology and aging of the Brazilian Academy of Neurology

ABSTRACT Since the publication of the latest recommendations for the diagnosis and treatment of Vascular Dementia by the Brazilian Academy of Neurology in 2011, significant advances on the terminology and diagnostic criteria have been made. This manuscript is the result of a consensus among experts appointed by the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology (2020-2022). We aimed to update practical recommendations for the identification, classification, and diagnosis of Vascular Cognitive Impairment (VCI). Searches were performed in the MEDLINE, Scopus, Scielo, and LILACS databases. This guideline provides a comprehensive review and then synthesizes the main practical guidelines for the diagnosis of VCI not only for neurologists but also for other professionals involved in the assessment and care of patients with VCI, considering the different levels of health care (primary, secondary and tertiary) in Brazil.

Manejo das demências em fase avançada: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO A doença de Alzheimer (DA) e outras demências neurodegenerativas têm um curso progressivo com comprometimento da cognição, capacidade funcional e comportamento. A maioria dos estudos enfocou a DA. A demência grave está associada ao aumento da idade, maior morbimortalidade e aumento dos custos de cuidados. É fundamental reconhecer que a demência grave é o período mais longo de progressão, com o paciente vivendo muitos anos nesta fase. É a fase mais heterogênea do processo, com diferentes habilidades e expectativa de vida. Esta diretriz de prática concentra-se na demência grave para melhorar o manejo e o cuidado nessa fase da demência. Como um longo período no continuum da demência, as abordagens não farmacológicas e farmacológicas devem ser consideradas. Intervenções multidisciplinares (fisioterapia, fonoaudiologia, nutrição, enfermagem, entre outras) são essenciais, além de educacionais e de apoio aos cuidadores.

Diagnosis of frontotemporal dementia: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT “Frontotemporal dementia” (FTD) is a clinical syndrome characterized by the focal involvement of the frontal and/or temporal lobes. FTD has three clinical phenotypes: the behavioral variant and two linguistic subtypes, namely, non-fluent/agrammatic primary progressive aphasia (PPA-NF/A) and semantic PPA (PPA-S). FTD is the second most common cause of dementia in individuals under the age of 65 years. This article presents recommendations for the diagnosis of FTD in the Brazilian scenario, considering the three levels of complexity of the health system: primary health care, secondary and tertiary levels. Diagnostic guidelines are proposed, including cognitive testing, behavioral and language assessments, laboratory tests, and neuroimaging.

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.