The Mex-Cog cognitive assessment battery: discriminant analysis of the cognitive performance profile in older adults

Objective. To analyze the cognitive profile of a clinical sample using the Mex-Cog cognitive battery and establish which cognitive measures and domains contribute most to group separation. Materials and methods. A group of 145 older adults previously diagnosed with dementia (n= 47), mild cognitive impairment MCI (n= 47), or as cognitively normal (n= 51) were assessed with the Mex-Cog cognitive battery. Six linear discriminant analyses (LDA) were estimated to compare dementia vs. cognitively normal, MCI vs. cognitively normal, and MCI vs. dementia, using ten individual measures and six cognitive domains. We used a leave-one-out cross-validation procedure to evaluate the predictive capacity of LDA models. Results. Discriminant functions using individual measures and domains distinguished correctly 100% of dementia and cognitively normal groups showing a memory and executive function profile. The predictive group membership for MCI versus cognitively normal varied between 82 and 85%, with a cognitive profile associated with attention-executive function followed by memory. Group separation between MCI and dementia was between 80 and 87%, characterized by orientation, memory, and visuospatial abilities. Conclusions. The Mex-Cog cognitive battery is useful for identifying cognitive impairment in older adults. - Objetivo. Analizar el perfil cognitivo de una muestra clínica en la batería cognitiva del Mex-Cog y determinar cuáles medidas cognitivas y dominios contribuyen más a separar los grupos. Material y métodos. Se aplicó la batería cognitiva a un grupo de 145 adultos mayores previamente diagnosticados con demencia (n= 47), deterioro cognitivo leve (n= 47) y cognitivamente normales (n= 51). Se estimaron seis análisis discriminantes comparando los grupos demencia vs. cognitivamente normales, deterioro cognitivo leve vs. cognitivamente normales, y deterioro cognitivo leve vs. demencia, utilizando diez medidas cognoscitivas y seis dominios. Para determinar la capacidad predictiva de los modelos discriminantes se realizó un análisis de validación cruzada. Resultados. Las funciones discriminantes, con las medidas cognoscitivas individuales o los dominios utilizados como predictores, clasificaron correctamente en 100% de los adultos con demencia y cognitivamente normales, observándose un perfil determinado por medidas de memoria y función ejecutiva. La clasificación de los grupos con deterioro cognitivo leve y cognitivamente normal osciló entre 82 y 85% con un perfil cognitivo asociado con medidas de atención-función ejecutiva seguido de medidas de memoria. La separación entre los grupos con deterioro cognitivo leve y demencia estuvo en el rango de 80 a 87%, caracterizado por medidas de orientación, memoria y habilidades visoespaciales. Conclusiones. La batería cognitiva del Mex-Cog es útil para identificar el deterioro cognitivo en adultos mayores

A task force for diagnosis and treatment of people with Alzheimer’s disease in Latin America

Alzheimer’s disease (AD) represents a substantial burden to patients, their caregivers, health systems, and society in Latin America and the Caribbean (LAC). This impact is exacerbated by limited access to diagnosis, specialized care, and therapies for AD within and among nations. The region has varied geographic, ethnic, cultural, and economic conditions, which create unique challenges to AD diagnosis and management. To address these issues, the Americas Health Foundation convened a panel of eight neurologists, geriatricians, and psychiatrists from Argentina, Brazil, Colombia, Ecuador, Guatemala, Mexico, and Peru who are experts in AD for a three-day virtual meeting to discuss best practices for AD diagnosis and treatment in LAC and create a manuscript offering recommendations to address identified barriers. In LAC, several barriers hamper diagnosing and treating people with dementia. These barriers include access to healthcare, fragmented healthcare systems, limited research funding, unstandardized diagnosis and treatment, genetic heterogeneity, and varying social determinants of health. Additional training for physicians and other healthcare workers at the primary care level, region-specific or adequately adapted cognitive tests, increased public healthcare insurance coverage of testing and treatment, and dedicated search strategies to detect populations with gene variants associated with AD are among the recommendations to improve the landscape of AD

Neuroimaging Characteristics of Small-Vessel Disease in Older Adults with Normal Cognition, Mild Cognitive Impairment, and Alzheimer Disease

Introduction: Cerebral small-vessel disease (SVD) represents the most frequent type of vascular brain lesions, often coexisting with Alzheimer disease (AD). By quantifying white matter hyperintensities (WMH) and hippocampal and parietal atrophy, we aimed to describe the prevalence and severity of SVD among older adults with normal cognition (NC), mild cognitive impairment (MCI), and probable AD and to describe associated risk factors. Methods: This study included 105 older adults evaluated with magnetic resonance imaging and clinical and neuropsychological tests. We used the Fazekas scale (FS) for quantification of WMH, the Scheltens scale (SS) for hippocampal atrophy, and the Koedam scale (KS) for parietal atrophy. Logistic regression models were performed to determine the association between FS, SS, and KS scores and the presence of NC, MCI, or probable AD. Results: Compared to NC subjects, SVD was more prevalent in MCI and probable AD subjects. After adjusting for confounding factors, logistic regression showed a positive association between higher scores on the FS and probable AD (OR = 7.6, 95% CI 2.7–20, p < 0.001). With the use of the SS and KS (OR = 4.5, 95% CI 3.5–58, p = 0.003 and OR = 8.9, 95% CI 1–72, p = 0.04, respectively), the risk also remained significant for probable AD. Conclusions: These results suggest an association between severity of vascular brain lesions and neurodegeneration

Cerebral Vascular Reactivity in Frail Older Adults with Vascular Cognitive Impairment

Background: Frailty, a state of increased vulnerability, could play a role in the progression of vascular dementia. We aim to describe the changes in cerebrovascular reactivity of older adults with frailty and vascular-type mild cognitive impairment (MCIv). Methods: This was a cross-sectional study. A comprehensive geriatric assessment, neuropsychological evaluation, and transcranial Doppler ultrasound (TCD) was performed on 180 participants who were allocated into four groups: healthy (n = 74), frail (n = 40), MCIv (n = 35), and mixed (frail + MCIv) (n = 31). ANOVA and Kruskal–Wallis tests were used for the analysis of continuous variables with and without normal distribution. Multinomial logistic regression was constructed to identify associated covariates. Results: Subjects in the mixed group, compared to healthy group, were older (75.0 ± 5.9 vs 70.3 ± 5.9 years; p < 0.001), showed lower education (9.3 ± 6.4 vs 12.2 ± 4.0 years; p = 0.054), greater frequency of diabetes (42% vs 12%; p = 0.005), worse cognitive performance (z = −0.81 ± 0.94), and reduced left medial-cerebral artery cerebrovascular reactivity (0.43 ± 0.42 cm/s). The mixed group was associated with age (odds ratio (OR) 1.16, 95% Confidence Interval (CI) = 1.06–1.27; p < 0.001), diabetes (OR 6.28, 1.81–21.84; p = 0.004), and Geriatric Depression Scale (GDS) score (OR 1.34, 95% CI = 1.09–1.67; p = 0.007). Conclusions: Frailty among older adults was associated with worse cognitive performance, diabetes, and decreased cerebral blood flow