Cognitive performance in community-dwelling older adults with stroke and the contribution of age and diffuse subcortical damage: a population-based study in rural Ecuador (The Atahualpa Project)

Predictors of Cognitive Functions After Stroke Assessed Using the Wechsler Adult Intelligence Scale: A Retrospective Study

Background

The mechanism(s) of cognitive impairment remains complex, making it difficult to confirm the factors influencing poststroke cognitive impairment (PSCI).

Objective

This study quantitatively investigated the degree of influence and interactions of clinical indicators of PSCI.

Methods

Information from 270 patients with PSCI and their Wechsler Adult Intelligence Scale (WAIS-RC) scores, totaling 18 indicators, were retrospectively collected. Correlations between the indicators and WAIS scores were calculated. Multiple linear regression model(MLR), genetic algorithm modified Back-Propagation neural network(GA-BP), logistic regression model (LR), XGBoost model (XGB), and structural equation model were used to analyze the degree of influence of factors on the WAIS and their mediating effects.

Results

Seven indicators were significantly correlated with the WAIS scores: education, lesion side, aphasia, frontal lobe, temporal lobe, diffuse lesions, and disease course. The MLR showed significant effect of education, lesion side, aphasia, diffuse lesions, and frontal lobe on the WAIS. The GA-BP included five factors: education, aphasia, frontal lobe, temporal lobe, and diffuse lesions. LR predicted that the lesion side contributed more to mild cognitive impairment, while education, lesion side, aphasia, and course of the disease contributed more to severe cognitive impairment. XGB showed that education, side of the lesion, aphasia, and diffuse lesions contributed the most to PSCI. Aphasia plays a significant mediating role in patients with severe PSCI.

Conclusions

Education, lesion side, aphasia, frontal lobe, and diffuse lesions significantly affected PSCI. Aphasia is a mediating variable between clinical information and the WAIS in patients with severe PSCI.

Ethnodemographic characterization of stroke incidence and burden of disease in hospital discharge records in Ecuador

Introduction

Stroke is the second most common cause of death and disability-adjusted life years (DALYs) globally. However, the incidence and impact of stroke by ethnicity and gender is frequently distinct. This is particularly the case in Ecuador where geographic and economic marginalization are often correlated with ethnic marginalization and the extent to which females lack the same opportunities as their male counterparts. The aim of this paper is to investigate the differential impacts in terms of stroke diagnosis and burden of disease by ethnicity and gender, using hospital discharge records over the years 2015-2020.

Methods

This paper calculates stroke incidence, and fatality rates using hospital discharge and death records over the years 2015-2020. The DALY package in R was employed to calculate the Disability Adjusted Life Years lost due to stroke in Ecuador.

Results

The results show that while the incidence rate of stroke in males (64.96 per 100,000 persons-year) is higher than that for females on average (57.84 per 100,000 persons-year), males accounted for 52.41% of all stroke cases and 53% of all surviving cases. Thus, hospital data suggests that females had a higher death rate when compared to males. Case fatality rates also differed significantly by ethnicity. The highest fatality rate corresponded to the Montubio ethnic group (87.65%), followed by Afrodescendants (67.21%). The estimated burden of disease of stroke calculated using Ecuadorian hospital records (2015-2020) varied from 1,468 to 2,991 DALY per 1,000 population on average.

Discussion

Differences in the burden of disease by ethnic group are likely to reflect differential access to care by region and socio-economic group, both of which are frequently correlated with ethnic composition in Ecuador. Equitable access to health services remains an important challenge in the country. The gender discrepancy in fatality rates suggests that there is a need for targeted educational campaigns to identify stroke signs early, especially in the female population.

Association between Blood Pressure, Blood Pressure Variability, and Post-Stroke Cognitive Impairment

After stroke, dynamic changes take place from necrotic-apoptotic continuum, inflammatory response to poststroke neurogenesis, and remodeling of the network. These changes and baseline brain pathology such as small vessel disease (SVD) and amyloid burden may be associated with the occurrence of early or late poststroke cognitive impairment (PSCI) or dementia (PSD), which affect not only stroke victims but also their families and even society. We reviewed the current concepts and understanding of the pathophysiology for PSCI/PSD and identified useful tools for the diagnosis and the prediction of PSCI in serological, CSF, and image characteristics. Then, we untangled their relationships with blood pressure (BP) and blood pressure variability (BPV), important but often overlooked risk factors for PSCI/PSD. Finally, we provided evidence for the modifying effects of BP and BPV on PSCI as well as pharmacological and non-pharmacological interventions and life style modification for PSCI/PSD prevention and treatment.

Total cerebral small vessel disease score and cognitive performance in community-dwelling older adults. Results from the Atahualpa Project

OBJECTIVE

Cerebral small vessel disease (SVD) is inversely associated with cognitive performance. However, whether the total SVD score is a better predictor of poor cognitive performance than individual signatures of SVD is inconclusive. We aimed to estimate the combined and independent predictive power of these MRI findings.

METHODS

Atahualpa residents aged ≥60 years underwent brain MRI. Cognitive performance was measured by the Montreal Cognitive Assessment (MoCA). The presence of moderate-to-severe white matter hyperintensities, deep cerebral microbleeds, lacunar infarcts, and >10 enlarged perivascular spaces was added for estimating the total SVD score ranging from 0 to 4 points. Montreal Cognitive Assessment predictive models were fitted to assess how well the total SVD score or each of its components predicts cognitive performance.

RESULTS

Of 351 eligible candidates, 331 (94%) were included. The total SVD score was 0 points in 202 individuals (61%), 1 point in 67 (20%), 2 points in 40 (12%), 3 points in 15 (5%), and 4 points in seven (2%). A generalized lineal model showed an inverse relationship between the total SVD score and the MoCA (p = 0.015). The proportion of variance in the MoCA score explained by the SVD score was 32.8% (R²  = 0.328). This predictive power was similar for white matter hyperintensities (R²  = 0.306), microbleeds (R²  = 0.313), lacunar infarcts (R²  = 0.323), and perivascular spaces (R²  = 0.313).

CONCLUSIONS

This study shows a significant association between the SVD score and worse cognitive performance. The SVD score is a predictor of poor cognitive performance. This predictive power is not better than that of isolated neuroimaging signatures of SVD. Copyright © 2017 John Wiley & Sons, Ltd.

Calcifications in the carotid siphon correlate with silent cerebral small vessel disease in community-dwelling older adults: A population-based study in rural Ecuador

AIM

Using a population-based, cross-sectional design, we aimed to assess whether the presence of calcifications in the carotid siphon (as seen on computed tomography) is associated with silent markers of cerebral small vessel disease (on magnetic resonance imaging) in apparently healthy older adults living in Atahualpa, a rural Ecuadorian village.

METHODS

Stroke-free Atahualpa residents aged ≥60 years identified during a door-to-door survey underwent head computed tomography for assessment of carotid siphon calcifications, and brain magnetic resonance imaging for identification of white matter hyperintensities and silent lacunar infarcts. We evaluated the association between calcifications and markers of small vessel disease using logistic regression models adjusted for demographics and cardiovascular risk factors.

RESULTS

The mean age of the 236 participants was 71 ± 8 years, and 139 (59%) were women. Computed tomography readings showed high calcium content in the carotid siphon in 64 individuals (27%), and magnetic resonance imaging showed moderate-to-severe white matter hyperintensities in 51 (30%) and lacunar infarcts in 28 (12%). In the univariate analysis, individuals with high calcium content were older and were more likely to have high fasting glucose levels than those with low calcium content. After adjusting for confounding variables, we found an independent association between high calcium content in the carotid siphon and moderate-to-severe white matter hyperintensities (OR 2.3, 95% CI 1.1-4.9, P = 0.035) as well as lacunar infarcts (OR 3.1, 95% CI 1.3-7.6, P = 0.013).

CONCLUSIONS

The present study shows a direct relationship between calcium content in the carotid siphon and silent small vessel disease in an indigenous Latin American population. Geriatr Gerontol Int 2016; 16: 1063-1067.