Cognitive function in Mexican older adults 6-months after recovering from SARS-CoV-2 infection.

BACKGROUND: SARS-CoV-2 infection has been associated with multiple short- and long-term complications including depression, and cognitive impairment (CI). However, older adults with CI after COVID-19 have not been fully documented. OBJECTIVE: To evaluate cognitive function in Mexican adults post-recovery from SARS-CoV-2 infection. METHODS: In this prospective observational cohort study, we assess cognitive function (CF) by the Montreal Cognitive Assessment (MOCA) test with a cut-off less than 26 points, and functional status via telemedicine. Eligible patients with a history of moderate-severe COVID-19 aged ≥60 years, cognitively healthy (evaluated by Everyday Cognition Scale) and required admission to an intensive care unit (ICU) were included. Patients with history of dementia, stroke, and delirium during the cognitive evaluation were excluded. The association between CI and COVID-19 was assessed with a Cox regression model. RESULTS: From the 634 patients admitted to the ICU, 415 survived, afterward 308 were excluded and 107 were analyzed. Mean age was 70 years, 58% were female, and 53% had severe COVID. The mean MoCA score was 21±5 points, CI was present in 61 patients (57%). Infection severity (RR 1.87; 95% CI: 1.11-3.15, p<0.05), lower education (RR 0.92; 95% CI: 0.87-0.97, p<0.01), and activity daily living disability (RR 1.87; 95% CI: 1.07-3.26, p<0.05) were the main factors associated with CI (unadjusted model by age and sex). The delayed recall, orientation, and language (83.2, 77.6 and 72.9% respectively) domains were the most affected in patients with CI. CONCLUSIONS: Fifty-seven percent of patients analyzed developed CI six months post-ICU discharge due to SARS-CoV-2, and COVID severity was the main factor associated to its outcome.

Advancements in dementia research, diagnostics, and care in Latin America: Highlights from the 2023 Alzheimer's Association International conference satellite symposium in Mexico City.

INTRODUCTION: While Latin America (LatAm) is facing an increasing burden of dementia due to the rapid aging of the population, it remains underrepresented in dementia research, diagnostics, and care. METHODS: In 2023, the Alzheimer's Association hosted its eighth satellite symposium in Mexico, highlighting emerging dementia research, priorities, and challenges within LatAm. RESULTS: Significant initiatives in the region, including intracountry support, showcased their efforts in fostering national and international collaborations; genetic studies unveiled the unique genetic admixture in LatAm; researchers conducting emerging clinical trials discussed ongoing culturally specific interventions; and the urgent need to harmonize practices and studies, improve diagnosis and care, and use affordable biomarkers in the region was highlighted. DISCUSSION: The myriad of topics discussed at the 2023 AAIC satellite symposium highlighted the growing research efforts in LatAm, providing valuable insights into dementia biology, genetics, epidemiology, treatment, and care.

Brain health index as a predictor of possible vascular dementia in the Mexican health and aging study 2012-2015.

To determine the burden of disease among subjects at risk of developing stroke or dementia, brain health indexes (BHI) tend to rely on anatomical features. Recent definitions emphasize the need of a broader perspective that encompasses cardiovascular risk factors (CVRFS) and lifestyle components which can be considered partial contributors to optimal brain health. In this study, we aimed to establish the association and risk detected by a Brain Health Index and the risk of possible vascular dementia (PVD) using data from the Mexican Health and Aging Study (MHAS) 2012-2015. The MHAS is a longitudinal study of adults aged ≥ 50 years. We analyzed the data obtained between 2012 and 2015. CVRFS included in the index were diabetes mellitus, hypertension, myocardial infarction, depression, obesity, physical inactivity, and smoking history. A PVD diagnosis was established when scores in the Cross-Cultural Cognitive Examination were below reference norms and limitations in ≥1 instrumental activities of daily living and a history of stroke were present. A multinomial regression model was developed to determine the association between BHI scores and PVD. In 2015, 75 PVD cases were identified. Mean age was 67.1 ±13.2 years, 35.8% were female, and the mean educational level was 5.8 ±5.5 years. In cases with a higher score in the BHI, the model revealed a hazards ratio of 1.63 (95% CI: 1.63-1.64, p< 0.001) for PVD. In this longitudinal study, with the use of a feasible multifactorial BHI in the Mexican population, a greater score was associated with a 1.63-fold risk of developing PVD during the 3-year follow-up, while the risk for stroke was 1.75. This index could potentially be used to predict the risk of PVD in adults with modifiable CVRFS.

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.

Factors associated with functional decline in COVID-19 elderly survivors hospitalized in a tertiary care center.

BACKGROUND: The information on functional decline after hospitalization for COVID-19 is limited in older adults (OAs). OBJECTIVE: To determine the association of inflammation (ferritin) and coagulation markers (D-dimer) and clinical factors with the functional status of OAs who suffered from COVID-19 six months after hospital discharge in Mexico. MATERIAL AND METHODS: Ambispective cohort study of 158 patients older than 65 years hospitalized for moderate-severe COVID-19 with complete electronic records that would allow to collect information and to contact them six months after discharge. Functional impairment was defined as a decrease ≥ 10 points on the Barthel index. Using logistic regression analysis, the risk of association of biochemical and clinical factors with functional deterioration during follow-up was determined. RESULTS: 46.2% of participants exhibited functional decline. Associated factors included age ≥ 73 years (OR = 2.53), chronic kidney disease (OR = 4.57), an ABC-Goals score ≥ 8 (OR = 2.4), ferritin ≥ 605 ng/mL (OR = 3.94) and D-dimer ≥ 930 ng/mL (OR = 17.56). CONCLUSION: COVID-19 infection did not only represent a disease with a high risk of mortality during the acute phase, but is also associated with a high risk of functional impairment after hospital discharge.

ANTECEDENTES: La información acerca del deterioro funcional después de una hospitalización por COVID-19 es limitada en personas mayores (PM). OBJETIVO: Determinar la asociación entre marcadores de inflamación (ferritina), coagulación (dímero D), factores clínicos y el estado funcional de PM que padecieron COVID-19 a seis meses del alta hospitalaria en México. MATERIAL Y MÉTODOS: Estudio de cohorte ambispectiva de 158 pacientes mayores de 65 años hospitalizados por COVID-19 moderado-grave con expediente electrónico completo que permitiera recolectar información y contactarlos a los seis meses del alta. Se definió deterioro funcional como disminución ≥ 10 puntos del índice de Barthel. Mediante regresión logística se determinó el riesgo de asociación entre factores bioquímicos y clínicos y deterioro funcional en el tiempo de seguimiento. RESULTADOS: 46.2 % de los participantes presentó pérdida funcional. Los factores asociados fueron edad ≥ 73 años (RM = 2.53), enfermedad renal crónica (RM = 4.57), puntuación ABC-Goals ≥ 8 (RM = 2.4), ferritina ≥ 605 ng/mL (RM = 3.94) y dímero-D ≥ 930 ng/mL FEU (RM = 17.56). CONCLUSIÓN: La infección por COVID-19 no solo representa una enfermedad con alto riesgo de mortalidad durante la fase aguda, sino que también se asocia a un alto riesgo de deterioro funcional posterior al egreso hospitalario.

Cross-cultural adaptation of the everyday cognition scale (M-ECog) in older Mexican adults with cognitive impairment.

The Everyday Cognition (ECog) scale was created to evaluate the functional abilities of older adults across a wide range of abilities between normal aging and dementia. ECog screens cognitive alterations such as subjective cognitive decline (SCD) and mild cognitive impairment (MCI). This early recognition is done by the measurement of the ability to perform the activities of daily living (ADLs). Objective: To establish the cross-cultural adaptation, validity, and reliability of the ECog Mexican version (M-ECog) in participants with: SCD, MCI, and dementia coming from a memory clinic. Methods: There were 200 patients and their respective informants in a memory clinic of a third level hospital in Mexico City. Four groups were studied: 50 cognitively healthy (CH), 50 SCD, 50 MCI, and 50 dementia. The clinical evaluation included: sociodemographic and health characteristics, cognitive status by the Mini-Mental State Evaluation (MMSE) and Montreal Cognitive Evaluation Spanish version (MoCA-E), and caregiver information (informants) about the difficulty in ADLs as well as the ECog Spanish version (M-ECog). Results: The M-ECog was significantly correlated with MMSE, MoCA-E, and ADLs. It showed the ability to discriminate the different cognitive declines (Cronbach's alpha 0.881). The intra-class correlation coefficient was 0.877 (95% confidence interval - CI, 0.850-0.902; p<0.001). The patient's group area under curve (AUC) of M-ECog for SCD was 0.70 (95%CI 0.58-0.82, p<0.005), for MCI it was 0.94 (95%CI 0.89-0.99, p<0.001) and for dementia 0.86 (95%CI 0.79-0.92, p<0.001). Conclusion: The M-ECog scale proves to be valid and reliable for measuring everyday abilities mediated by cognition. It is self-applicable without requiring extensive prior formation. It is useful to screen for SCD and MCI in older Mexican adults.

A escala Cognição Cotidiana (ECog) foi criada para avaliar as habilidades funcionais de idosos em uma ampla gama de habilidades entre o envelhecimento normal e a demência. O ECog rastreia alterações cognitivas como declínio cognitivo subjetivo (DCS) e comprometimento cognitivo leve (CCL). Esse reconhecimento precoce é feito pela mensuração da capacidade de realizar as atividades de vida diária (AVD). Objetivo: Estabelecer a adaptação transcultural, validade e confiabilidade da versão mexicana do ECog (M-ECog) em participantes com: SCD, MCI e demência provenientes de uma clínica de memória. Métodos: Foram 200 pacientes e seus respectivos informantes em uma clínica de memória de um hospital de terceiro nível na Cidade do México. Quatro grupos foram estudados: 50 cognitivamente saudáveis (CH), 50 SCD, 50 MCI e 50 com demência. A avaliação clínica incluiu: características sociodemográficas e de saúde, estado cognitivo pelo Mini-Mental State Evaluation (MMSE) e Montreal Cognitive Evaluation versão em espanhol (MoCA-E), bem como informações do cuidador (informantes) sobre a dificuldade nas AVD e o ECog versão em espanhol (M-ECog). Resultados: O M-ECog foi significativamente correlacionado com MMSE, MoCA-E e AVD. Mostrou capacidade de discriminar os diferentes declínios cognitivos (alfa de Cronbach 0,881). O coeficiente de correlação intraclasse foi de 0,877 (intervalo de confiança de 95% ­ IC95%, 0,850­0,902; p<0,001). A AUC do grupo do paciente de M-ECog para SCD foi de 0,70 (IC95% 0,58­0,82, p<0,005), para MCI foi de 0,94 (IC95% 0,89­0,99, p<0,001) e para demência foi de 0,86 (IC95% 0,79­0,92, p<0,001). Conclusão: A escala M-ECog mostra-se válida e confiável para medir habilidades cotidianas mediadas pela cognição. É autoaplicável sem exigir extensa formação prévia. É útil para rastrear MSC e MCI em adultos mexicanos mais velhos.

Factores asociados al deterioro funcional en adultos mayores sobrevivientes de COVID-19 hospitalizados en un centro de tercer nivel / Factors associated with functional decline in COVID-19 elderly survivors hospitalized in a tertiary care center

Resumen Antecedentes: La información acerca del deterioro funcional después de una hospitalización por COVID-19 es limitada en personas mayores (PM). Objetivo: Determinar la asociación entre marcadores de inflamación (ferritina), coagulación (dímero D), factores clínicos y el estado funcional de PM que padecieron COVID-19 a seis meses del alta hospitalaria en México. Material y métodos: Estudio de cohorte ambispectiva de 158 pacientes mayores de 65 años hospitalizados por COVID-19 moderado-grave con expediente electrónico completo que permitiera recolectar información y contactarlos a los seis meses del alta. Se definió deterioro funcional como disminución ≥ 10 puntos del índice de Barthel. Mediante regresión logística se determinó el riesgo de asociación entre factores bioquímicos y clínicos y deterioro funcional en el tiempo de seguimiento. Resultados: 46.2 % de los participantes presentó pérdida funcional. Los factores asociados fueron edad ≥ 73 años (RM = 2.53), enfermedad renal crónica (RM = 4.57), puntuación ABC-Goals ≥ 8 (RM = 2.4), ferritina ≥ 605 ng/mL (RM = 3.94) y dímero-D ≥ 930 ng/mL FEU (RM = 17.56). Conclusión: La infección por COVID-19 no solo representa una enfermedad con alto riesgo de mortalidad durante la fase aguda, sino que también se asocia a un alto riesgo de deterioro funcional posterior al egreso hospitalario.

Abstract Background: The information on functional decline after hospitalization for COVID-19 is limited in older adults (OAs). Objective: To determine the association of inflammation (ferritin) and coagulation markers (D-dimer) and clinical factors with the functional status of OAs who suffered from COVID-19 six months after hospital discharge in Mexico. Material and methods: Ambispective cohort study of 158 patients older than 65 years hospitalized for moderate-severe COVID-19 with complete electronic records that would allow to collect information and to contact them six months after discharge. Functional impairment was defined as a decrease ≥ 10 points on the Barthel index. Using logistic regression analysis, the risk of association of biochemical and clinical factors with functional deterioration during follow-up was determined. Results: 46.2 % of participants exhibited functional decline. Associated factors included age ≥ 73 years (OR = 2.53), chronic kidney disease (OR = 4.57), an ABC-Goals score ≥ 8 (OR = 2.4), ferritin ≥ 605 ng/mL (OR = 3.94) and D-dimer ≥ 930 ng/mL (OR = 17.56). Conclusion: COVID-19 infection did not only represent a disease with a high risk of mortality during the acute phase, but is also associated with a high risk of functional impairment after hospital discharge.

Association between vitamin B12 levels and cognitive impairment in older adults.

INTRODUCTION: Whether vitamin B12 deficiency is associated with cognitive impairment remains controversial. OBJECTIVE: To determine the association between vitamin B12 serum levels and cognitive performance. METHODS: Two-hundred and forty-one adults aged ≥ 60 years who had serum vitamin B12 serum levels measurement were included. Physical and cognitive evaluation was carried out, and three groups were formed: normal cognition (NC), mild cognitive impairment (MCI) and dementia. Vitamin B12 levels were classified as sufficiency (> 400 pg/mL), subclinical deficiency (201-400 pg/mL), and absolute deficiency (≤ 200 pg/mL). Multivariate linear regression analysis was used to evaluate the association between cognitive function and vitamin B12 levels after controlling for confounding variables. RESULTS: Mean age was 81.4 ± 8.0 years; 68% were females; 17.8 % and 39.8% had absolute and subclinical vitamin B12 deficiency, respectively; 80 individuals (33%) met the criteria for MCI, and 70 (29%), for dementia. Those with MCI and dementia had lower vitamin B12 levels in comparison with those with NC after adjusting for age, gender and educational level (p = 0.019). CONCLUSIONS: A statistically significant association was observed between global cognitive performance and levels of vitamin B12.

INTRODUCCIÓN: Aún es controversial si la deficiencia de vitamina B12 se asocia a alteraciones cognitivas. OBJETIVO: Conocer la asociación entre los niveles séricos de vitamina B12 y el desempeño cognitivo. MÉTODOS: Se incluyeron 241 personas ≥ 60 años con medición de niveles séricos de vitamina B12. Se realizó evaluación física y cognitiva y se formaron tres grupos: cognición normal (CN), deterioro cognitivo leve (DCL) y demencia. Los niveles de vitamina B12 se clasificaron en suficiencia (> 400 pg/mL), deficiencia subclínica (201-400 pg/mL) y deficiencia absoluta (≤ 200 pg/mL). Se realizó análisis de regresión lineal multivariado para evaluar la asociación entre función cognitiva y niveles de vitamina B12 después de controlar las variables confusoras. RESULTADOS: La media de edad fue 81.4 ± 8.0 años; 68 % fue del sexo femenino; 17.8 y 39.8 % presentaron deficiencia absoluta y subclínica de vitamina B12; 80 individuos (33 %) cumplieron los criterios de DCL y 70 (29 %), de demencia. Después de ajustar por edad, sexo y escolaridad, los sujetos con DCL y demencia tuvieron niveles más bajos de vitamina B12 comparados con aquellos con CN (p = 0.019). CONCLUSIONES: Se observó asociación estadísticamente significativa entre el desempeño cognitivo global y los niveles bajos de vitamina B12.

Association of loneliness, social isolation, and daily cognitive function in Mexican older adults living in community during the first wave of COVID-19 pandemic / Asociación del aislamiento social, soledad y la función cognitiva cotidiana en adultos mayores mexicanos de la comunidad durante la primera ola del COVID-19

Abstract Introduction Loneliness and social isolation are known risk factors for cognitive decline; their effect in older adults (OA) after COVID-19 lockdown is emerging. Objective To establish an association between loneliness and social isolation, with daily cognitive function in Mexican OA during the first wave of the COVID-19 pandemic. Method Cross-sectional study, derived from the cohort "The impact of COVID 19 on well-being, cognition, and discrimination among older adults in the United States and Latin America", which included 308 OA recruited between March-August 2020 whose daily cognitive function were determined with the Everyday Cognition Scale (E-Cog) as dichotomized score (cut point: 1.31 for normal cognition). Loneliness and social isolation were binomial variables. Results The mean age was 65.4 ± 7.9 years, 75.7% were women. The mean continuous E-Cog score was 57.4 (SD = ± 19.1), 49.1% had a score < 1.31 (normal cognition), while 50.9% had a higher score (cognitive impairment). Eighty four percent of participants reported loneliness, 79.9% reported social isolation. Multivariate regression model showed a negative and statistically significant association between social isolation and loneliness and E-Cog, adjusted by age, sex and education level (β = -.046, 95% CI = [-.8, -.013], p = .007; β = -.16, 95% CI = [-.08, -.018], p = .003), and a positive association with subjective memory complaint (β = .81, 95% CI = [-.16, -.11], p = < .001). Discussion and conclusion These data suggest the need for increased vigilance of those who have loneliness and social isolation due to its potential deleterious effect on cognitive function.

Resumen Introducción La soledad y el aislamiento social son factores de riesgo conocidos para el deterioro cognitivo; su efecto en las personas mayores (PM) después del confinamiento por COVID-19 está emergiendo. Objetivo Establecer una asociación entre la soledad y el aislamiento social, con la función cognitiva diaria en PM mexicanas durante la primera ola de la pandemia por COVID-19. Método Estudio transversal derivado de la cohorte "The impact of COVID 19 on well-being, cognition, and discrimination among older adults in the United States and Latin America", incluyó 308 AM reclutados de marzo-agosto 2020, la función cognitiva diaria fue evaluada con Everyday Cognition Scale (E-Cog) con un punto de corte 1.31 (cognición normal); la soledad y el aislamiento social fueron variables binomiales. Resultados La media de edad fue 65.4 ± 7.9 años, 75.7% mujeres. E-Cog promedio fue 57.4 (DE = ± 19.1), 49.1 % tenía una puntuación < 1.31 (cognición normal), 50.9% > 1.31 (deterioro cognitivo). Ochenta y cuatro por ciento de los participantes reportaron soledad, 79.9% aislamiento social. El modelo de regresión multivariado mostró una asociación negativa y estadísticamente significativa entre aislamiento social y soledad con E-Cog (β = -.046, IC 95% = [-.8, -.013], p = .007; β = -.16, IC 95% = [-.08, -.018], p = .003), y una asociación positiva con queja de memoria subjetiva (β = .81, IC 95% = [-.16, -.11], p = < .001) ajustado a edad, sexo y escolaridad. Discusión y conclusión Estos datos sugieren la necesidad de una mayor vigilancia de quienes presentan soledad y aislamiento social debido a su potencial efecto deletéreo sobre la función cognitiva.

Asociación entre los niveles de vitamina B12 y el deterioro cognitivo en personas mayores / Association between vitamin B12 levels and cognitive impairment in older adults

Resumen Introducción: Aún es controversial si la deficiencia de vitamina B12 se asocia a alteraciones cognitivas. Objetivo: Conocer la asociación entre los niveles séricos de vitamina B12 y el desempeño cognitivo. Métodos: Se incluyeron 241 personas ≥ 60 años con medición de niveles séricos de vitamina B12. Se realizó evaluación física y cognitiva y se formaron tres grupos: cognición normal (CN), deterioro cognitivo leve (DCL) y demencia. Los niveles de vitamina B12 se clasificaron en suficiencia (> 400 pg/mL), deficiencia subclínica (201-400 pg/mL) y deficiencia absoluta (≤ 200 pg/mL). Se realizó análisis de regresión lineal multivariado para evaluar la asociación entre función cognitiva y niveles de vitamina B12 después de controlar las variables confusoras. Resultados: La media de edad fue 81.4 ± 8.0 años; 68 % fue del sexo femenino; 17.8 y 39.8 % presentaron deficiencia absoluta y subclínica de vitamina B12; 80 individuos (33 %) cumplieron los criterios de DCL y 70 (29 %), de demencia. Después de ajustar por edad, sexo y escolaridad, los sujetos con DCL y demencia tuvieron niveles más bajos de vitamina B12 comparados con aquellos con CN (p = 0.019). Conclusiones: Se observó asociación estadísticamente significativa entre el desempeño cognitivo global y los niveles bajos de vitamina B12.

Abstract Introduction: Whether vitamin B12 deficiency is associated with cognitive impairment remains controversial. Objective: To determine the association between vitamin B12 serum levels and cognitive performance. Methods: Two-hundred and forty-one adults aged ≥ 60 years who had serum vitamin B12 serum levels measurement were included. Physical and cognitive evaluation was carried out, and three groups were formed: normal cognition (NC), mild cognitive impairment (MCI) and dementia. Vitamin B12 levels were classified as sufficiency (> 400 pg/mL), subclinical deficiency (201-400 pg/mL), and absolute deficiency (≤ 200 pg/mL). Multivariate linear regression analysis was used to evaluate the association between cognitive function and vitamin B12 levels after controlling for confounding variables. Results: Mean age was 81.4 ± 8.0 years; 68% were females; 17.8 % and 39.8% had absolute and subclinical vitamin B12 deficiency, respectively; 80 individuals (33%) met the criteria for MCI, and 70 (29%), for dementia. Those with MCI and dementia had lower vitamin B12 levels in comparison with those with NC after adjusting for age, gender and educational level (p = 0.019). Conclusions: A statistically significant association was observed between global cognitive performance and levels of vitamin B12.

Cross-cultural adaptation of the everyday cognition scale (M-ECog) in older Mexican adults with cognitive impairment / Adaptação transcultural da escala de cognição cotidiana (M-ECog) em idosos mexicanos com comprometimento cognitivo

Abstract The Everyday Cognition (ECog) scale was created to evaluate the functional abilities of older adults across a wide range of abilities between normal aging and dementia. ECog screens cognitive alterations such as subjective cognitive decline (SCD) and mild cognitive impairment (MCI). This early recognition is done by the measurement of the ability to perform the activities of daily living (ADLs). Objective: To establish the cross-cultural adaptation, validity, and reliability of the ECog Mexican version (M-ECog) in participants with: SCD, MCI, and dementia coming from a memory clinic. Methods: There were 200 patients and their respective informants in a memory clinic of a third level hospital in Mexico City. Four groups were studied: 50 cognitively healthy (CH), 50 SCD, 50 MCI, and 50 dementia. The clinical evaluation included: sociodemographic and health characteristics, cognitive status by the Mini-Mental State Evaluation (MMSE) and Montreal Cognitive Evaluation Spanish version (MoCA-E), and caregiver information (informants) about the difficulty in ADLs as well as the ECog Spanish version (M-ECog). Results: The M-ECog was significantly correlated with MMSE, MoCA-E, and ADLs. It showed the ability to discriminate the different cognitive declines (Cronbach's alpha 0.881). The intra-class correlation coefficient was 0.877 (95% confidence interval — CI, 0.850-0.902; p<0.001). The patient's group area under curve (AUC) of M-ECog for SCD was 0.70 (95%CI 0.58-0.82, p<0.005), for MCI it was 0.94 (95%CI 0.89-0.99, p<0.001) and for dementia 0.86 (95%CI 0.79-0.92, p<0.001). Conclusion: The M-ECog scale proves to be valid and reliable for measuring everyday abilities mediated by cognition. It is self-applicable without requiring extensive prior formation. It is useful to screen for SCD and MCI in older Mexican adults.

RESUMO A escala Cognição Cotidiana (ECog) foi criada para avaliar as habilidades funcionais de idosos em uma ampla gama de habilidades entre o envelhecimento normal e a demência. O ECog rastreia alterações cognitivas como declínio cognitivo subjetivo (DCS) e comprometimento cognitivo leve (CCL). Esse reconhecimento precoce é feito pela mensuração da capacidade de realizar as atividades de vida diária (AVD). Objetivo: Estabelecer a adaptação transcultural, validade e confiabilidade da versão mexicana do ECog (M-ECog) em participantes com: SCD, MCI e demência provenientes de uma clínica de memória. Métodos: Foram 200 pacientes e seus respectivos informantes em uma clínica de memória de um hospital de terceiro nível na Cidade do México. Quatro grupos foram estudados: 50 cognitivamente saudáveis (CH), 50 SCD, 50 MCI e 50 com demência. A avaliação clínica incluiu: características sociodemográficas e de saúde, estado cognitivo pelo Mini-Mental State Evaluation (MMSE) e Montreal Cognitive Evaluation versão em espanhol (MoCA-E), bem como informações do cuidador (informantes) sobre a dificuldade nas AVD e o ECog versão em espanhol (M-ECog). Resultados: O M-ECog foi significativamente correlacionado com MMSE, MoCA-E e AVD. Mostrou capacidade de discriminar os diferentes declínios cognitivos (alfa de Cronbach 0,881). O coeficiente de correlação intraclasse foi de 0,877 (intervalo de confiança de 95% — IC95%, 0,850-0,902; p<0,001). A AUC do grupo do paciente de M-ECog para SCD foi de 0,70 (IC95% 0,58-0,82, p<0,005), para MCI foi de 0,94 (IC95% 0,89-0,99, p<0,001) e para demência foi de 0,86 (IC95% 0,79-0,92, p<0,001). Conclusão: A escala M-ECog mostra-se válida e confiável para medir habilidades cotidianas mediadas pela cognição. É autoaplicável sem exigir extensa formação prévia. É útil para rastrear MSC e MCI em adultos mexicanos mais velhos.

Prevalence of Dementia and Main Subtypes in Mexico: The Study on Aging and Dementia in Mexico (SADEM).

BACKGROUND: Dementia is a priority public health issue due to its high prevalence worldwide and its economic, social, and health impact. However, there are few reports in Mexico based on formal tests and with a clinical approach based on the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). OBJECTIVE: This study estimates the prevalence of the main types of dementia among elderly people living in the community in Mexico City. METHODS: A population-based, two-step study was conducted, including 6,204 elderly individuals aged 60 or above with in-home assessment. All participants were screened for cognitive impairment; those who presented some cognitive problem underwent a standardized neurological examination. Each diagnosis was based on the criteria for dementia in the DSM-5, and the final consensus diagnosis of dementia was determined by an expert panel. RESULTS: The global estimated prevalence of dementia in the Mexican population was 7.8% met the criteria for Alzheimer's disease, 4.3% for vascular dementia, and 2.1% for mixed dementia. The prevalence of dementia was higher in women than in men (15.3% versus 12.5%, respectively). CONCLUSION: These results provide evidence to propose strategies for Latin American countries where dementia represents a challenge due to the heterogeneity of the populations and socioeconomic disparities, requiring early diagnosis and at the first levels of care.

ASSOCIATION BETWEEN APOE-ε4 CARRIER STATUS AND QUALITATIVE NEUROIMAGING CHARACTERISTICS IN OLDER ADULTS WITH MILD COGNITIVE IMPAIRMENT.

BACKGROUND: The pathogenesis of mild cognitive impairment (MCI) is multifactorial and includes the presence of genetic variants such as the ε4 allele of the apolipoprotein E gene (APOE-ε4). Association between the APOE-ε4 carrier status and deleterious structural and functional changes on magnetic resonance imaging (MRI) has been previously described in individuals with Alzheimer's disease. However, the central nervous system changes may possibly develop in earlier stages of cognitive impairment, as reflected in MCI. OBJECTIVE: The objective of the study was to determine the association between APOE-ε4 carrier status and qualitative changes on MRI (medial temporal and parietal atrophy), as well as the detection of white matter hyperintensities (WMH) in older adults with MCI, in the memory clinic of a tertiary care hospital in Mexico City. METHODS: A cross-sectional study of 72 adults aged 60 years or above who underwent an exhaustive clinical, neuroimaging, and neuropsychological evaluation. Multivariate logistic regression models were constructed to determine the association between APOE-ε4 carrier status and qualitative/quantitative changes on MRI. RESULTS: Mean age was 75.2 years (± 7.2) and 64% were female. Twenty-one participants were cognitively normal and 51 had MCI. Almost 56% were APOE-ε4 carriers and were associated with medial-temporal atrophy according to the Scheltens scale (odds ratio [OR]: 20.0, 95% confidence intervals [CI]: 3.03-131.7), parietal atrophy according to the Koedam's score (OR: 6.3; 95% CI 1.03-39.53), and WMH according to the Fazekas scale (OR: 11.7, 95% CI: 1.26-108.2), even after adjusting for age, educational level, and cardiovascular risk factors. CONCLUSION: The APOE-ε4 carrier status was associated with medial temporal and parietal atrophy, as well as WMH. Our findings support the hypothesis suggesting the contribution of this genotype to neurodegeneration and cerebral vascular pathology.

Use of Fast Gamma Magnetic Stimulation Over the Left Prefrontal Dorsolateral Cortex for the Treatment of MCI and Mild Alzheimer's Disease: A Double-Blind, Randomized, Sham-Controlled, Pilot Study.

Background: Alzheimer's disease (AD) animal models have shown a reduced gamma power in several brain areas, and induction of these oscillations by non-invasive methods has been shown to modify several pathogenic mechanisms of AD. In humans, the application of low-intensity magnetic fields has shown to be able to produce neural entrainment at the magnetic pulse frequency, making it useful to induce gamma frequencies. Objective: The aim of this study was to assess if the application of fast gamma magnetic stimulation (FGMS) over the left prefrontal dorsolateral cortex would be a safe and well-tolerated intervention that could potentially improve cognitive scores in subjects with mild cognitive impairment and mild AD. Methods: In these randomized, double-blind, sham-controlled study, participants were assigned to either receive daily sessions two times a day of active or sham FGMS for 6 months. Afterward, measurements of adverse effects, cognition, functionality, and depression were taken. Results: Thirty-four patients, 17 in each group, were analyzed for the primary outcome. FGMS was adequately tolerated by most of the subjects. Only four patients from the active FGMS group (23.52%) and one patient from the sham FGMS group (5.88%) presented any kind of adverse effects, showing no significant difference between groups. Nevertheless, FGMS did not significantly change cognitive, functionality, or depressive evaluations. Conclusion: FGMS over the left prefrontal dorsolateral cortex applied twice a day for 6 months resulted to be a viable intervention that can be applied safely directly from home without supervision of a healthcare provider. However, no statistically significant changes in cognitive, functionality, or depression scores compared to sham stimulation were observed. Clinical Trial Registration:www.ClinicalTrials.gov, Identifier: NCT03983655, URL: https://clinicaltrials.gov/ct2/show/NCT03983655.

Prevalence and incidence of possible vascular dementia among Mexican older adults: Analysis of the Mexican Health and Aging Study.

INTRODUCTION: Vascular dementia is the second most common cause of dementia. Physical disability and cognitive impairment due to stroke are conditions that considerably affect quality of life. We estimated the prevalence and incidence of possible vascular dementia (PVD) in older adults using data from the Mexican Health and Aging Study (MHAS 2012 and 2015 waves). METHODS: The MHAS is a representative longitudinal cohort study of Mexican adults aged ≥50 years. Data from 14, 893 participants from the 2012 cohort and 14,154 from the 2015 cohort were analyzed to estimate the prevalence and incidence of PVD. Self-respondents with history of stroke were classified as PVD if scores in two or more cognitive domains in the Cross-Cultural Cognitive Examination were ≥ 1.5 standard deviations below the mean on reference norms and if limitations in ≥ 1 instrumental activities of daily living were present. For proxy respondents with history of stroke, we used a score ≥3.4 on the Informant Questionnaire on Cognitive Decline in the Elderly. Crude and standardized rates of prevalent and incident PVD were estimated. RESULTS: Prevalence of PVD was 0.6% (95% CI, 0.5-0.8) (0.5 with age and sex- standardization). Rates increased with age reaching 2.0% among those aged 80 and older and decreased with educational attainment. After 3.0 years of follow-up, 87 new cases of PVD represented an overall incident rate of 2.2 (95% CI, 1.7-2.6) per 1,000 person-years (2.0 with age and sex- standardization). Incidence also increased with advancing age reaching an overall rate of 9.4 (95% CI, 6.3-13.6) per 1,000 person-years for participants aged >80 years. Hypertension and depressive symptoms were strong predictors of incident PVD. CONCLUSION: These data provide new estimates of PVD prevalence and incidence in the Mexican population. We found that PVD incidence increased with age. Males aged 80 years or older showed a greater incidence rate when compared to females, which is comparable to previous estimates from other studies.

Comparison of the Impact of Zika and Dengue Virus Infection, and Other Acute Illnesses of Unidentified Origin on Cognitive Functions in a Prospective Cohort in Chiapas Mexico.

Zika has been associated with a variety of severe neurologic manifestations including meningitis and encephalitis. We hypothesized that it may also cause mild to subclinical neurocognitive alterations during acute infection or over the long term. In this observational cohort study, we explored whether Zika cause subclinical or mild neurocognitive alterations, estimate its frequency and duration, and compare it to other acute illnesses in a cohort of people with suspected Zika infection, in the region of Tapachula in Chiapas, Mexico during 2016-2018. We enrolled patients who were at least 12 years old with suspected Zika virus infection and followed them up for 6 months. During each visit participants underwent a complete clinical exam, including a screening test for neurocognitive dysfunction (Montreal Cognitive Assessment score). We enrolled 406 patients [37 with Zika, 73 with dengue and 296 with other acute illnesses of unidentified origin (AIUO)]. We observed a mild and transient impact over cognitive functions in patients with Zika, dengue and with other AIUO. The probability of having an abnormal MoCA score (<26 points) was significantly higher in patients with Zika and AIUO than in those with dengue. Patients with Zika and AIUO had lower memory scores than patients with dengue (Zika vs. Dengue: -0.378, 95% CI-0.678 to -0.078; p = 0.014: Zika vs. AIUO 0.264, 95% CI 0.059, 0.469; p = 0.012). The low memory performance in patients with Zika and AIUO accounts for most of the differences in the overall MoCA score when compared with patients with dengue. Our results show a decrease in cognitive function during acute illness and provides no evidence to support the hypothesis that Zika might cause neurocognitive alterations longer than the period of acute infection or different to other infectious diseases. While effects on memory or perhaps other cognitive functions over the long term are possible, larger studies using more refined tools for neurocognitive functioning assessment are needed to identify these. Trial Registration: NCT02831699.

The Social Vulnerability Index, Mortality and Disability in Mexican Middle-Aged and Older Adults.

The social vulnerability index (SVI) independently predicts mortality and others adverse outcomes across different populations. There is no evidence that the SVI can predict adverse outcomes in individuals living in countries with high social vulnerability such as Latin America. The aim of this study was to analyze the association of the SVI with mortality and disability in Mexican middle-aged and older adults. This is a longitudinal study with a follow-up of 47 months, the Mexican Health and Aging Study, including people over the age of 40 years. A SVI was calculated using 42 items stratified in three categories low (<0.36), medium (0.36-0.47), and high (>0.47) vulnerability. We examined the association of SVI with three-year mortality and incident disability. Cox and logistic regression models were fitted to test these associations. We included 14,217 participants (58.4% women) with a mean age of 63.9 years (±SD 10.1). The mean SVI was of 0.42 (±SD 0.12). Mortality rate at three years was 6% (n = 809) and incident disability was 13.2% (n = 1367). SVI was independently associated with mortality, with a HR of 1.4 (95% CI 1.1-1.8, p < 0.001) for the highest category of the SVI compared to the lowest. Regarding disability, the OR was 1.3 (95% CI 1.1-1.5, p = 0.026) when comparing the highest and the lowest levels of the SVI. The SVI was independently associated with mortality and disability. Our findings support previous evidence on the SVI and builds on how this association persists even in those individuals with underlying contextual social vulnerability.

Association between ApoE ε4 Carrier Status and Cardiovascular Risk Factors on Mild Cognitive Impairment among Mexican Older Adults.

Mild cognitive impairment (MCI) (amnestic or non-amnestic) has different clinical and neuropsychological characteristics, and its evolution is heterogeneous. Cardiovascular risk factors (CVRF), such as hypertension, diabetes, or dyslipidemia, and the presence of the Apolipoprotein E ε4 (ApoE ε4) polymorphism have been associated with an increased risk of developing Alzheimer's disease (AD) and other dementias but the relationship is inconsistent worldwide. We aimed to establish the association between the ApoE ε4 carrier status and CVRF on MCI subtypes (amnestic and non-amnestic) in Mexican older adults. Cross-sectional study including 137 older adults (n = 63 with normal cognition (NC), n = 24 with amnesic, and n = 50 with non-amnesic MCI). Multinomial logistic regression models were performed in order to determine the association between ApoE ε4 polymorphism carrier and CVRF on amnestic and non-amnestic-MCI. ApoE ε4 carrier status was present in 28.8% participants. The models showed that ApoE ε4 carrier status was not associated neither aMCI nor naMCI condition. The interaction term ApoE ε4 × CVRF was not statistically significant for both types of MCI. However, CVRF were associated with both types of MCI and the association remained statistically significant after adjustment by sex, age, and education level. The carrier status of the ApoE genotype does not contribute to this risk.

Prevention, diagnosis, and treatment of delirium in older adults with COVID-19. Literature review / Prevención, diagnóstico y tratamiento del delirium en adultos mayores con COVID-19. Revisión de la literatura

Abstract Background COVID-19 affects several systems in the body, including the central nervous system (CNS), expressed in the form of headaches, hyposmia, cerebrovascular disease, and neuropathy. Older Adults (OA) are vulnerable to this infection, and may also present delirium, which may be the result of the virus directly affecting the CNS or of systemic inflammation during infection. Objective To determine the clinical characteristics, risk factors, pathophysiology, treatment measures, and prevention of delirium associated with COVID-19 from a review of the literature in times of the SARS-CoV-2 pandemic. Method A search was conducted in PubMed, SciELO, UpToDate, and Medscape using keywords in English and Spanish. Results Seventy-two articles were reviewed. We analyzed inclusion and exclusion criteria and 43 articles with relevant information for the narrative description of the review were selected. Twenty to thirty per cent of the COVID-19 patients will present or develop delirium, or changes in mental status during their hospitalization, with rates of 60% to 70% in severe illness. The exact mechanisms are likely to be multifactorial. There is a worrying lack of attention to the implications of identifying and managing delirium in the response to this pandemic. Discussion and conclusion Delirium is a frequent neurological manifestation in OA with COVID-19 and requires early identification, as well as the implementation of non-pharmacological and pharmacological treatment strategies, which may reduce the associated morbidity and mortality in this age group.

Resumen Antecedentes La COVID-19 afecta múltiples sistemas del organismo. Uno de ellos es el sistema nervioso central (SNC), cuya afección se manifiesta con cefalea, hiposmia, enfermedad vascular cerebral y neuropatía. Además de que los adultos mayores (AM) son vulnerables a esta infección, pueden presentar delirium, el cual puede ser resultado de una afección directa del virus al SNC o resultado de la inflamación sistémica durante la infección. Objetivo Conocer las características clínicas, factores de riesgo, fisiopatología, medidas de tratamiento y prevención del delirium asociados a COVID-19 a partir de la revisión de la literatura en tiempos de la pandemia por SARS-CoV-2. Método Se realizó una búsqueda en PubMed, SciELO, UpToDate y Medscape utilizando palabras clave en inglés y español. Resultados Se revisaron 72 artículos, se analizaron criterios de inclusión y exclusión y se seleccionaron 43 artículos con información relevante para la descripción narrativa de la revisión. El 20-30% de los pacientes con COVID-19 presentarán o desarrollarán delirium, o cambios en su estado mental durante el curso de su hospitalización, con tasas del 60-70% en enfermedad grave. Es probable que los mecanismos exactos sean multifactoriales. Existe una preocupante falta de atención a las implicaciones de la identificación y el manejo del delirium en la respuesta a esta pandemia. Discusión y conclusión El delirium es una manifestación neurológica frecuente en los AM con COVID-19 y requiere su identificación temprana, así como la implementación de estrategias de tratamiento no farmacológico y farmacológico, lo que puede disminuir la morbimortalidad asociada en este grupo etario.

Effect of poor glycemic control in cognitive performance in the elderly with type 2 diabetes mellitus: The Mexican Health and Aging Study.

BACKGROUND: Cognitive impairment is twice more frequent in elderly with type 2 diabetes mellitus (DM). This study was conducted to determine the association between glycemic control and cognitive performance among community-dwelling elderly persons in Mexico. METHODS: Cross-sectional study conducted in individuals aged 60 years or elderly participating in the 2012 Mexican Health and Aging Study. Type 2 DM participants were classified in 3 groups according to their glycated hemoglobin levels (HbA1c): < 7% (intensive control), 7-7.9% (standard control) or ≥ 8% (poor control), and cognitive performance: low (CCCE ≤44 points), intermediate (44.1-59.52 points), or high (≥59.53 points). Multinomial logistic regression models were constructed to determine this association. RESULTS: Two hundred sixteen community-dwelling adults aged 60 and older with type 2 diabetes were selected. Subjects in the low cognitive performance group were older (69.7 ± 6.6 vs 65.86 ± 5.18 years, p < .001) and had a lower educational level (2.5 ± 2.6 vs 7.44 ± 4.15 years, p < .000) when compared to the high cognitive performance participants. HbA1c ≥ 8% was associated with having low (Odds Ratio (OR) 3.17, 95% CI 1.17-8.60, p = .024), and intermediate (OR 3.23, 95% CI 1.27-8.20, p = .014) cognitive performance; this trend was not found for HbA1c 7.0-7.9% group. The multinomial regression analysis showed that the presence of HbA1c ≥ 8% (poor glycemic control) was associated with low (OR 3.17, 95% CI = 1.17-8.60, p = .024), and intermediate (OR 3.23, 95% CI = 1.27-8.20, p = .014) cognitive performance. After adjusting for confounding variables. CONCLUSIONS: Glycemic control with a HbA1c ≥ 8% was associated with worse cognitive performance.