The prevalence and severity of white matter lesions, their relationship with age, ethnicity, gender, and cardiovascular disease risk factors: the ARIC Study

White matter hyperintensities in diverse populations: A systematic review of literature in the United States

As the United States' (US) elderly population becomes increasingly diverse, it is imperative that research studies address cognitive health in diverse populations of older Americans. White Matter Hyperintensities (WMH) are useful imaging findings that can be studied in elderly individuals and have been linked to an increased risk of neurological conditions, such as stroke, cognitive impairment, and dementia. We performed a systematic review of literature using PubMed sources to compile all the studies that investigated the prevalence of ethnic and racial differences of WMH burden amongst diverse groups in the US. We identified 23 unique articles that utilized 16 distinct cohorts of which 94 % were prospective, longitudinal studies that included community-based and family-based populations. The overall results were heterogenous in all aspects of data collection and analysis, limiting our ability to run meta-analyses and draw definitive conclusions. General observations suggest increased vascular risk on African American populations, contributing to greater WMH burden in that population. Overall, the findings of this study indicate a need for a standardized approach to investigating WMH in efforts to measure its clinical impact on diverse populations.

White matter hyperintensity burden and functional outcomes in acute ischemic stroke patients after mechanical thrombectomy: A systematic review and meta-analysis

BACKGROUND

The influence of white matter hyperintensity (WMH) on clinical outcomes in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT) remains controversial. We performed a systematic review and meta-analysis to examine whether WMH burden is associated with clinical outcomes in AIS patients after MT.

METHODS

PubMed, Embase, and Web of Science were searched from inception to Sep 03, 2023. The registration number for PROSPERO is CRD42022340568. Studies reporting an association between the burden of WMH in AIS patients and clinical outcomes after MT were included in the meta-analysis. A random-effects model was used for meta-analysis. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Additionally, the presence of imprecise-study effects was evaluated using Egger's test and funnel plot.

RESULTS

Fifteen studies with 3,456 patients were enrolled in this meta-analysis. Among AIS patients who underwent MT, moderate/severe WMH had higher odds of 90-day unfavorable functional outcomes (odds ratio [OR] 2.72, 95% confidence interval [CI] 2.14-3.44; I2 = 0.0%; 95% CI 0.0%-42.7%), 90-day mortality (OR 1.94, 95% CI 1.45-2.60; I2 = 19.5%; 95% CI 0.0%-65.2%) and futile recanalization (OR 2.99, 95% CI 1.42-6.28; I2 = 69.7%; 95% CI 0.0%-91.0%) compared with none/mild WMH. However, the two groups had no significant difference in successful recanalization, symptomatic hemorrhagic transformation, and hemorrhagic transformation. A subset analysis of patients from 3 articles showed that WMH volume was not significantly associated with these outcomes. A notable limitation is that this meta-analysis lacks direct adjustment for imbalances in important baseline covariates.

CONCLUSIONS

Patients with moderate/severe WMH on baseline imaging are associated with substantially increased odds of 90-day unfavorable outcomes, futile recanalization, and 90-day mortality after MT. This association suggests that moderate/severe WMH may contribute to the prediction of clinical outcomes in AIS patients after MT.

Racial/Ethnic Variation in White Matter Hyperintensity Progression in the ACCORDION MIND Study

BACKGROUND

White matter hyperintensities (WMHs) are linked to cognitive decline and stroke. We investigate the impact of race on WMH progression in the Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes (ACCORDION MIND) trial.

MATERIALS AND METHODS

The primary outcome is WMH progression in milliliters, evaluated by fitting linear regression to WMH volume on the month 80 magnetic resonance imaging (MRI) and including the WMH volume on the baseline MRI. The primary predictor is patient race, with the exclusion of patients defined as "other" race. We also derived predicted probabilities of our outcome for systolic blood pressure (SBP) levels.

RESULTS

We included 276 patients who completed the baseline and month 80 MRI, of which 207 (75%) were White, 48 (17%) Black, and 21 (8%) Hispanic. During follow-up, the mean number of SBP, low-density lipoprotein (LDL), and A1c measurements per patient was 21, 8, and 15. The median (IQR) WMH progression was 1.5 mL (0.5 to 3.9) for Black patients, 1.0 mL (0.4 to 4.0) for Hispanics, and 1.3 mL (0.5 to 2.7) for Whites (Kruskal-Wallis test, P =0.59). In the multivariate regression model, Black, compared with White, patients had significantly more WMH progression (β Coefficient 1.26, 95% confidence interval 0.45 to 2.06, P =0.002). Hispanic, compared with White, patients neither have significantly different WMH progression ( P =0.392), nor was there a difference when comparing Hispanic to Black patients ( P =0.162). The predicted WMH progression was significantly higher for Black compared with White patients across a mean SBP of 117 to 139 mm Hg.

CONCLUSIONS

Black diabetic patients in Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes (ACCORDION MIND) have a higher risk of WMH progression than White patients across a normal range of SBP.

The association between white matter hyperintensities and amyloid and tau deposition

White matter hyperintensities (WMHs) frequently occur in Alzheimer's Disease (AD) and have a contribution from ischemia, though their relationship with β-amyloid and cardiovascular risk factors (CVRFs) is not completely understood. We used AT classification to categorize individuals based on their β-amyloid and tau pathologies, then assessed the effects of β-amyloid and tau on WMH volume and number. We then determined regions in which β-amyloid and WMH accumulation were related. Last, we analyzed the effects of various CVRFs on WMHs. As secondary analyses, we observed effects of age and sex differences, atrophy, cognitive scores, and APOE genotype. PET, MRI, FLAIR, demographic, and cardiovascular health data was collected from the Alzheimer's Disease Neuroimaging Initiative (ADNI-3) (N = 287, 48 % male). Participants were categorized as A + and T + if their Florbetapir SUVR and Flortaucipir SUVR were above 0.79 and 1.25, respectively. WMHs were mapped on MRI using a deep convolutional neural network (Sepehrband et al., 2020). CVRF scores were based on history of hypertension, systolic and diastolic blood pressure, pulse rate, respiration rate, BMI, and a cumulative score with 6 being the maximum score. Regression models and Pearson correlations were used to test associations and correlations between variables, respectively, with age, sex, years of education, and scanner manufacturer as covariates of no interest. WMH volume percent was significantly associated with global β-amyloid (r = 0.28, p < 0.001), but not tau (r = 0.05, p = 0.25). WMH volume percent was higher in individuals with either A + or T + pathology compared to controls, particularly within in the A+/T + group (p = 0.007, Cohen's d = 0.4, t = -2.5). Individual CVRFs nor cumulative CVRF scores were associated with increased WMH volume. Finally, the regions where β-amyloid and WMH count were most positively associated were the middle temporal region in the right hemisphere (r = 0.18, p = 0.002) and the fusiform region in the left hemisphere (r = 0.017, p = 0.005). β-amyloid and WMH have a clear association, though the mechanism facilitating this association is still not fully understood. The associations found between β-amyloid and WMH burden emphasizes the relationship between β-amyloid and vascular lesion formation while factors like CVRFs, age, and sex affect AD development through various mechanisms. These findings highlight potential causes and mechanisms of AD as targets for future preventions and treatments. Going forward, a larger emphasis may be placed on β-amyloid's vascular effects and the implications of impaired brain clearance in AD.

Early Prediction in Classification of Cardiovascular Diseases with Machine Learning, Neuro-Fuzzy and Statistical Methods

Timely and accurate detection of cardiovascular diseases (CVDs) is critically important to minimize the risk of a myocardial infarction. Relations between factors of CVDs are complex, ill-defined and nonlinear, justifying the use of artificial intelligence tools. These tools aid in predicting and classifying CVDs. In this article, we propose a methodology using machine learning (ML) approaches to predict, classify and improve the diagnostic accuracy of CVDs, including support vector regression (SVR), multivariate adaptive regression splines, the M5Tree model and neural networks for the training process. Moreover, adaptive neuro-fuzzy and statistical approaches, nearest neighbor/naive Bayes classifiers and adaptive neuro-fuzzy inference system (ANFIS) are used to predict seventeen CVD risk factors. Mixed-data transformation and classification methods are employed for categorical and continuous variables predicting CVD risk. We compare our hybrid models and existing ML techniques on a CVD real dataset collected from a hospital. A sensitivity analysis is performed to determine the influence and exhibit the essential variables with regard to CVDs, such as the patient's age, cholesterol level and glucose level. Our results report that the proposed methodology outperformed well known statistical and ML approaches, showing their versatility and utility in CVD classification. Our investigation indicates that the prediction accuracy of ANFIS for the training process is 96.56%, followed by SVR with 91.95% prediction accuracy. Our study includes a comprehensive comparison of results obtained for the mentioned methods.

Neurobiological Mechanisms of Cognitive Decline Correlated with Brain Aging

Cognitive decline has emerged as one of the greatest health threats of old age. Meanwhile, aging is the primary risk factor for Alzheimer's disease (AD) and other prevalent neurodegenerative disorders. Developing therapeutic interventions for such conditions demands a greater understanding of the processes underlying normal and pathological brain aging. Despite playing an important role in the pathogenesis and incidence of disease, brain aging has not been well understood at a molecular level. Recent advances in the biology of aging in model organisms, together with molecular- and systems-level studies of the brain, are beginning to shed light on these mechanisms and their potential roles in cognitive decline. This chapter seeks to integrate the knowledge about the neurological mechanisms of age-related cognitive changes that underlie aging.

Association of estimated white matter hyperintensity age with cognition in elderly with controlled hypertension

INTRODUCTION

Hypertension is associated with white matter hyperintensity (WMH) and cognitive impairment. Further, WMH is associated with cognitive impairment including executive, attention and visuospatial functions. The aim of this study was to investigate the effects of controlled hypertension (cHT) and previously developed concept, 'WMH age' on cognitive function and the mediating role of WMH in the effect of cHT on cognitive impairment.

METHODS

We enrolled 855 Koreans without dementia aged 60 years or older, 326 of whom completed 2-year follow-up assessment. We measured their blood pressure thrice in a sitting position using an automated blood pressure monitoring device. We estimated 'WMH age' of every participant using previously developed WMH probability map of healthy older Koreans. We analyzed the mediating effect of WMH age in the association of cHT and cognitive function using the PROCESS Macro model.

RESULTS

Old WMH age was associated with a faster decline in the Mini-Mental Status Examination (MMSE; p =.003), Consortium to Establish a Registry for Alzheimer's Disease total score (CERAD-TS; p =.003), and Frontal Assessment Battery (FAB; p =.007). Old WMH age showed an approximately-six times higher risk of incident mild cognitive impairment (OR = 6.47, 95 % CI = 1.37 - 9.50, p =.024) compared to young or normal WMH age over the 2-year follow-up period in the cHT group. WMH age mediated the effects of cHT on the MMSE, CERAD-TS, and FAB scores at baseline and two-year follow-up period.

CONCLUSIONS

WMH mediates the adverse effect of hypertension on cognitive function. Elders with cHT who have older WMH age may be at a higher risk of cognitive decline.

Race, sex, and mid-life changes in brain health: Cardia MRI substudy

OBJECTIVE

To examine longitudinal race and sex differences in mid-life brain health and to evaluate whether cardiovascular health (CVH) or apolipoprotein E (APOE) ε4 explain differences.

METHODS

The study included 478 Black and White participants (mean age: 50 years). Total (TBV), gray (GMV), white (WMV), and white matter hyperintensity (WMH) volumes and GM-cerebral blood flow (CBF) were acquired with 3T-magnetic resonance imaging at baseline and 5-year follow-up. Analyses were based on general linear models.

RESULTS

There were race x sex interactions for GMV (P-interaction = .004) and CBF (P-interaction = .01) such that men showed more decline than women, and this was most evident in Blacks. Blacks compared to Whites had a significantly greater increase in WMH (P = .002). All sex-race differences in change were marginally attenuated by CVH and APOE ε4.

CONCLUSION

Race-sex differences in brain health emerge by mid-life. Identifying new environmental factors beyond CVH is needed to develop early interventions to maintain brain health.

Impact of the ambulatory blood pressure monitoring profile on cognitive and imaging findings of cerebral small-vessel disease in older adults with cognitive complaints

We investigated ambulatory blood pressure (BP) monitoring (ABPM) profiles and magnetic resonance imaging (MRI) findings of cerebral small-vessel disease (cSVD) in older adults with cognitive complaints who were grouped as follows: subjective cognitive decline, mild cognitive impairment, and dementia of Alzheimer's type. Group comparisons and correlation analyses among demographic characteristics, cognitive and MRI findings, and ABPM profiles were performed. Furthermore, multivariate logistic regression analyses for dependent variables of (1) dementia or not and (2) MRI criteria of subcortical vascular dementia (SVaD) or not were conducted with independent variables of dichotomized ABPM profiles. A total of 174 subjects (55 males and 119 females) were included: mean age 75.36 ± 7.13 years; Mini-Mental State Examination (MMSE) score 20.51 ± 6.23. No MRI and ABPM findings except medial temporal atrophy were different between three groups. Twenty-four-hour systolic BP (sBP) was correlated with MMSE score (r = -0.182; p = 0.022) and the severity of white matter hyperintensity (WMH) (r = 0.157; p = 0.048). A higher daytime sBP was associated with dementia (odds ratio (OR): 3.734; 95% confidence interval (CI): 1.041-13.390; p = 0.043) and MRI finding of SVaD (OR: 10.543; 95% CI: 1.161-95.740; p = 0.036). Although there were no differences in ABPM profiles between three groups, a higher BP-especially a higher sBP-correlated with cognitive dysfunction and severity of WMH in older adults. Only higher daytime sBP was an independent predictor for dementia and MRI findings of SVaD. Among various ABPM profiles in this study, a higher BP, especially a higher sBP, may be considered the most important for clinical and MRI findings of cSVD.

Pathways linking abdominal obesity to poor memory function: Explore the mediating role of hypertension and depressive symptoms

BACKGROUND

The negative effect of abdominal obesity on cognitive function has been widely reported, especially on memory function, however, it is unclear how the effect is mediated. We aim to investigate the mediating role of hypertension and depressive symptoms.

METHODS

Data were collected from wave 6 (2012-2013) of the English Longitudinal Study of Ageing (ELSA). Abdominal obesity was defined as a waist circumference (WC) ≥88cm for women and ≥102cm for men. Hypertension was determined on the basis of objective blood pressure measurement and previous physician diagnosis. Depressive symptoms were assessed with the 8-item version of the Center for Epidemiologic Studies (CESD) scale. Memory function was measured with the 10-word immediate and delayed recall tests. Baron and Kenny's causal steps and Karlson/Holm/Breen (KHB) method were used to examine the mediating effect.

RESULTS

A total of 7,448 participants aged ≥50 years were included in this study. We found a negative effect of abdominal obesity on memory function (β=-0.047, p=0.031). KHB method identified significant mediating effect of hypertension and depressive symptoms on the relationship between abdominal obesity and memory function, they explained 16.92 and 6.32% of the total effect of abdominal obesity on memory function, respectively.

LIMITATIONS

This study was limited by its cross-sectional design and possibility of residual confounding.

CONCLUSIONS

Hypertension and depressive symptoms might be possible pathways linking abdominal obesity and poor memory function, suggesting that collaborative interventions of abdominal obesity, hypertension and depressive symptoms are beneficial in maintaining memory function.

Burden and correlates of cognitive impairment among hypertensive patients in Tanzania: a cross-sectional study

BACKGROUND

The evolution of cognitive impairment of vascular origin is increasingly becoming a prominent health threat particularly in this era where hypertension is the leading contributor of global disease burden and overall health loss. Hypertension is associated with the alteration of the cerebral microcirculation coupled by unfavorable vascular remodeling with consequential slowing of mental processing speed, reduced abstract reasoning, loss of linguistic abilities, and attention and memory deficits. Owing to the rapidly rising burden of hypertension in Tanzania, we sought to assess the prevalence and correlates of cognitive impairment among hypertensive patients attending a tertiary cardiovascular hospital in Tanzania.

METHODOLOGY

A hospital-based cross-sectional study was conducted at Jakaya Kikwete Cardiac Institute, a tertiary care public teaching hospital in Dar es Salaam, Tanzania between March 2020 and February 2021. A consecutive sampling method was utilized to recruit consented hypertensive outpatients during their scheduled clinic visit. General Practitioner Assessment of Cognition (GPCOG) Score was utilized in the assessment of cognitive functions. All statistical analyses utilized STATA v11.0 software. Pearson Chi square and Student's T-test were used to compare categorical and continuous variables respectively. Logistic regression analyses were used to assess for factors associated with cognitive impairment. Odd ratios with 95% confidence intervals and p-values are reported. All tests were 2-sided and p < 0.05 was used to denote a statistical significance.

RESULTS

A total of 1201 hypertensive patients were enrolled in this study. The mean age was 58.1 years and females constituted nearly two-thirds of the study population. About three quarters had excess body weight, 16.6% had diabetes, 7.7% had history of stroke, 5.7% had heart failure, 16.7% had renal dysfunction, 53.7% had anemia, 27.7% had hypertriglyceridemia, 38.5% had elevated LDL, and 2.4% were HIV-infected. Nearly two-thirds of participants had uncontrolled blood pressure and 8.7% had orthostatic hypotension. Overall, 524 (43.6%) of participants had cognitive impairment. During bivariate analysis in a logistic regression model of 16 characteristics, 14 parameters showed association with cognitive functions. However, after controlling for confounders, multivariate analysis revealed ≤primary education (OR 3.5, 95%CI 2.4-5.2, p < 0.001), unemployed state (OR 1.7, 95%CI 1.2-2.6, p < 0.01), rural habitation (OR 1.8, 95%CI 1.1-2.9, p = 0.01) and renal dysfunction (OR 1.7, 95%CI 1.0-2.7, p = 0.04) to have independent association with cognitive impairment.

CONCLUSION

This present study underscore that cognitive decline is considerably prevalent among individuals with systemic hypertension. In view of this, it is pivotal to incorporate cognitive assessment in routine evaluation of hypertensive patients.

Sex Differences in Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis

Background: Cerebral small vessel disease (SVD) is a common cause of stroke, mild cognitive impairment, dementia and physical impairments. Differences in SVD incidence or severity between males and females are unknown. We assessed sex differences in SVD by assessing the male-to-female ratio (M:F) of recruited participants and incidence of SVD, risk factor presence, distribution, and severity of SVD features. Methods: We assessed four recent systematic reviews on SVD and performed a supplementary search of MEDLINE to identify studies reporting M:F ratio in covert, stroke, or cognitive SVD presentations (registered protocol: CRD42020193995). We meta-analyzed differences in sex ratios across time, countries, SVD severity and presentations, age and risk factors for SVD. Results: Amongst 123 relevant studies (n = 36,910 participants) including 53 community-based, 67 hospital-based and three mixed studies published between 1989 and 2020, more males were recruited in hospital-based than in community-based studies [M:F = 1.16 (0.70) vs. M:F = 0.79 (0.35), respectively; p < 0.001]. More males had moderate to severe SVD [M:F = 1.08 (0.81) vs. M:F = 0.82 (0.47) in healthy to mild SVD; p < 0.001], and stroke presentations where M:F was 1.67 (0.53). M:F did not differ for recent (2015-2020) vs. pre-2015 publications, by geographical region, or age. There were insufficient sex-stratified data to explore M:F and risk factors for SVD. Conclusions: Our results highlight differences in male-to-female ratios in SVD severity and amongst those presenting with stroke that have important clinical and translational implications. Future SVD research should report participant demographics, risk factors and outcomes separately for males and females. Systematic Review Registration: [PROSPERO], identifier [CRD42020193995].

White Matter Integrity and Nicotine Dependence: Evaluating Vertical and Horizontal Pleiotropy

Tobacco smoking is an addictive behavior that supports nicotine dependence and is an independent risk factor for cancer and other illnesses. Its neurogenetic mechanisms are not fully understood but may act through alterations in the cerebral white matter (WM). We hypothesized that the vertical pleiotropic pathways, where genetic variants influence a trait that in turn influences another trait, link genetic factors, integrity of cerebral WM, and nicotine addiction. We tested this hypothesis using individual genetic factors, WM integrity measured by fractional anisotropy (FA), and nicotine dependence-related smoking phenotypes, including smoking status (SS) and cigarettes per day (CPDs), in a large epidemiological sample collected by the UK Biobank. We performed a genome-wide association study (GWAS) to identify previously reported loci associated with smoking behavior. Smoking was found to be associated with reduced WM integrity in multiple brain regions. We then evaluated two competing vertical pathways: Genes → WM integrity → Smoking versus Genes → Smoking → WM integrity and a horizontal pleiotropy pathway where genetic factors independently affect both smoking and WM integrity. The causal pathway analysis identified 272 pleiotropic single-nucleotide polymorphisms (SNPs) whose effects on SS were mediated by FA, as well as 22 pleiotropic SNPs whose effects on FA were mediated by CPD. These SNPs were mainly located in important susceptibility genes for smoking-induced diseases NCAM1 and IREB2. Our findings revealed the role of cerebral WM in the maintenance of the complex addiction and provided potential genetic targets for future research in examining how changes in WM integrity contribute to the nicotine effects on the brain.

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Obesity and Race May Explain Differential Burden of White Matter Hyperintensity Load

OBJECTIVE

Compared to European Americans, research indicates that African Americans have higher white matter hyperintensity (WMH) load; however, the clinical and biological bases underlying this higher burden are poorly understood. We hypothesize that obesity may explain differences in WMH between African and European Americans.

METHODS

Participants enrolled in longitudinal brain aging studies (n=292; 61% Female; 92% European American; mean age=69.6±7.7) completed evaluations including medical exams, neuroimaging, and sociodemographic surveys. Overweight/obese status defined as body mass index ≥30 kg/m2, and WMH load, captured by FLAIR images, as sum of deep and periventricular volumes, scored using the Fazekas scale (0-6), WMH≥4 considered high.

RESULTS

Logistic regression analyses, adjusted for age, sex, hypertension, and smoking history, indicated that age and interaction between race and obesity were significant predictors of WMH, demonstrating that obesity significantly moderated the relationship between race and WMH. Age independently increased the odds of high WMH by 16% (OR=1.16, 95% CI=1.09-1.23, p<0.001). Stratified analysis indicates that older European Americans had increased WMH (OR=1.17, 95% CI=1.09-1.23, p<0.001), while obese African Americans had increased WMH (OR=27.65, 95% CI=1.47-519.13, p<0.05). In a case controlled subgroup matched by age, sex, and education (n=48), African Americans had significantly higher WMH load (27% vs 4%, Χ 2=5.3, p=0.02).

CONCLUSION

Results denote that age predicted WMH among European Americans, while obesity predicted WMH among African Americans. Matched sample analyses indicate that obesity increases the odds of WMH, though more pronounced in African Americans. These findings suggest that obesity may explain the differential burden of white matter hyperintensity load, signifying public health and clinical importance.

Reflection on modern methods: shared-parameter models for longitudinal studies with missing data

A primary goal of longitudinal studies is to examine trends over time. Reported results from these studies often depend on strong, unverifiable assumptions about the missing data. Whereas the risk of substantial bias from missing data is widely known, analyses exploring missing-data influences are commonly done either ad hoc or not at all. This article outlines one of the three primary recognized approaches for examining missing-data effects that could be more widely used, i.e. the shared-parameter model (SPM), and explains its purpose, use, limitations and extensions. We additionally provide synthetic data and reproducible research code for running SPMs in SAS, Stata and R programming languages to facilitate their use in practice and for teaching purposes in epidemiology, biostatistics, data science and related fields. Our goals are to increase understanding and use of these methods by providing introductions to the concepts and access to helpful tools.

Association of Carotid Atherosclerosis With White Matter Hyperintensity in an Asymptomatic Japanese Population: A Cross-Sectional Study

Objective: A limited number of scholars concentrated on the relationship between carotid atherosclerosis (CAS) and white matter hyperintensity (WMH) (i.e., CAS-WMH relationship). The current research aimed to clarify the CAS-WMH relationship in Japanese population.

Methods: All participants underwent MRI of head and ultrasonography of the carotid artery. WMH was diagnosed from MRI results. The carotid ultrasound findings, carotid artery plaque score (PS), and plaque number (PN) could be achieved to indicate the severity of CAS. We also employed multivariate logistic regression models to estimate the CAS-WMH relationship. Interaction and stratified analyses were undertaken on the basis of a number of factors (e.g., gender, age, smoking status, drinking habit, and history of chronic diseases).

Results: A total of 1,904 Japanese subjects were included, and the prevalence of WMH was 54.8% (1,044/1,904). It was unveiled that frequency of CAS was greater in cases with WMH. In a fully adjusted model, high PS was associated with the frequency of WMH, followed by high PN. Further analyses revealed a dose-response relationship between PS and incidence of WMH.

Conclusion: PS and PN exhibited the greatest influences on determining the frequency of WMH, highlighting the potentially important pathophysiological role of large artery atherosclerosis in intensifying WMH.

Use of levamisole-adulterated cocaine is associated with increased load of white matter lesions

Background

Cocaine use has been associated with vascular pathologies, including cerebral white matter hyperintensities. Street cocaine is most often adulterated with levamisole, an anthelminthic drug that may also be associated with vascular toxicity. However, whether levamisole exposure from cocaine consumption further accelerates the development of white matter lesions remains unknown.

Methods

We investigated the association of cocaine and levamisole exposure with white matter hyperintensities in 35 chronic cocaine users and 34 healthy controls. We measured cocaine and levamisole concentrations in hair samples, which reflected exposure up to 6 months previously. We assessed the number and total surface area of the white matter hyperintensities using structural MRI (FLAIR sequence). Using generalized linear models, we analyzed the contributions of cocaine and levamisole to the number and area of white matter hyperintensities, accounting for several confounding factors.

Results

Analysis using generalized linear models revealed that cocaine users had more white matter hyperintensities in terms of total surface area, but not in terms of number. Further generalized linear models that included cocaine and levamisole hair concentrations (instead of group) as predictors indicated that levamisole exposure was strongly associated with more and larger white matter hyperintensities, suggesting that the elevated white matter hyperintensities in cocaine users were driven mainly by levamisole exposure. Finally, white matter hyperintensities in levamisole-exposed cocaine users were located primarily in the periventricular and juxtacortical white matter.

Limitations

The sample size was moderate, and blood pressure was not systematically assessed.

Conclusion

As an adulterant of cocaine, levamisole appears to increase the risk of white matter injury.

Construction and validation of a cerebral white matter hyperintensity probability map of older Koreans

•

We constructed WPM from healthy elderly Koreans.

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WPM may serve as a tool to study pathology and normal aging of distribution of WMH.

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WPM provides a prominent atlas of the age related distribution of WMH.

Background and purpose

Although two white matter hyperintensity (WMH) probability maps of healthy older adults already exist, they have several limitations in representing the distribution of WMH in healthy older adults, especially Asian older adults. We constructed and validated a WMH probability map (WPM) of healthy older Koreans and examined the age-associated differences of WMH.

Methods

We constructed WPM using development dataset that consisted of high-resolution 3D fluid-attenuated inversion recovery images of 5 age groups (60–64 years, 65–69 years, 70–74 years, 75–79 years, and 80+ years). Each age group included 30 age-matched men and women each. We tested the validity of the WPM by comparing WMH ages estimated by the WPM and the chronological ages of 30 healthy controls, 30 hypertension patients, and 30 S patients.

Results

Older age groups showed a higher volume of WMH in both hemispheres (p < 0.001). About 90% of the WMH were periventricular in all age groups. With advancing age, the peak of the distance histogram from the ventricular wall of the periventricular WMH shifted away from the ventricular wall, while that of deep WMH shifted toward the ventricular wall. The estimated WMH ages were comparable to the chronological ages in the healthy controls, while being higher than the chronological ages in hypertension and stroke patients.

Conclusions

This WPM may serve as a standard atlas in research on WMH of older adults, especially Asians.

Multiscale Dynamics of Blood Pressure Fluctuation Is Associated With White Matter Lesion Burden in Older Adults With and Without Hypertension: Observations From a Pilot Study

Background: White matter lesions (WMLs) are highly prevalent in older adults, and hypertension is one of the main contributors to WMLs. The blood pressure (BP) is regulated by complex underlying mechanisms over multiple time scales, thus the continuous beat-to-beat BP fluctuation is complex. The association between WMLs and hypertension may be manifested as diminished complexity of BP fluctuations. The aim of this pilot study is to explore the relationships between hypertension, BP complexity, and WMLs in older adults. Method: Fifty-three older adults with clinically diagnosed hypertension and 47 age-matched older adults without hypertension completed one MRI scan and one BP recording of 10-15 min when sitting quietly. Their cerebral WMLs were assessed by two neurologists using the Fazekas scale based on brain structural MRI of each of their own. Greater score reflected higher WML grade. The complexity of continuous systolic (SBP) and diastolic (DBP) BP series was quantified using multiscale entropy (MSE). Lower MSE reflected lower complexity. Results: Compared to the non-hypertensive group, hypertensives had significantly greater Fazekas scores (F > 5.3, p < 0.02) and lower SBP and DBP complexity (F > 8.6, p < 0.004). Both within each group (β < -0.42, p < 0.01) and across groups (β < -0.47, p < 0.003), those with lower BP complexity had higher Fazekas score. Moreover, complexity of both SBP and DBP mediated the influence of hypertension on WMLs (indirect effects > 0.25, 95% confidence intervals = 0.06 - 0.50). Conclusion: These results suggest that diminished BP complexity is associated with WMLs and may mediate the influence of hypertension on WMLs. Future longitudinal studies are needed to examine the causal relationship between BP complexity and WMLs.

Arterial Stiffness in Aging: Does It Have a Place in Clinical Practice?: Recent Advances in Hypertension

Aortic stiffness increases markedly with age and is associated with excess risk for various adverse clinical outcomes, including heart disease, dementia, and kidney disease. Although evidence for adverse effects of aortic stiffening is overwhelming, integration of direct and indirect measures of aortic stiffness into routine clinical assessment has lagged behind the science. This brief review will examine recent evidence supporting the value of stiffness as an important new risk factor for hypertension and cardiovascular disease and will offer suggestions for incorporating stiffness measures into routine clinical practice.

Microvascular Brain Disease Progression and Risk of Stroke: The ARIC Study

BACKGROUND AND PURPOSE

Data on the significance of combined white matter hyperintensities (WMH)/lacunar brain infarcts, and their progression over time for the prediction of stroke are scarce. We studied associations between the progression in combined measures of microvascular brain disease and risk of stroke in the ARIC study (Atherosclerosis Risk in Communities).

METHODS

Prospective analysis of 907 stroke-free ARIC participants who underwent a brain magnetic resonance imaging (MRI) in 1993 to 1995, a second brain MRI in 2004 to 2006, and were subsequently followed for stroke incidence through December 31, 2017 (median [25%-75%] follow-up 12.6 [8.9-13.4] years). A combined measure of microvascular brain disease was defined at each visit and categorized by progression from first to second brain MRI as no progression; mild progression (increase of ≥1 unit in WMH grade or new lacune), and moderate progression (increase of ≥1 unit in WMH grade and new lacune). All definite/probable ischemic or hemorrhagic incident strokes occurring after this second MRI, and through 2017, were included. Associations between microvascular brain disease, progression in the combined measures, and stroke incidence were studied with Cox proportional hazard models, adjusting for age, sex, race, education level, time from first to second MRI, body mass index, smoking, hypertension, diabetes mellitus, and coronary heart disease.

RESULTS

At the second brain MRI (mean age 72), the distribution of the combined measure was 37% WMH grade <2 and no lacune; 57% WMH grade ≥2 or lacune; and 6% WMH grade ≥2 and lacune. No progression in the combined measures was observed in 38% of participants, 57% showed mild progression and 5% showed moderate progression. Sixty-four incident strokes occurred during the follow-up period. Compared with no change in the combined measure, moderate progression of microvascular brain disease was significantly associated with higher risk of stroke (adjusted hazard ratio, 3.00 [95% CI, 1.30-6.94]).

CONCLUSIONS

Progression of microvascular brain disease, manifesting as both new lacunes and increase in WMHs grade, is related to substantial increase in long-term risk of stroke.

Twenty-Four-Hour Ambulatory Blood Pressure Variability Associated With Cerebral Small Vessel Disease MRI Burden and Its Progression in Inpatients With Cerebrovascular Disease

Background: Lacunar infarcts, white matter lesions, cerebral microbleed, enlarged perivascular space and brain atrophy are regarded as magnetic resonance imaging (MRI) manifestations of cerebral small vessel disease (cSVD). 24-hour blood pressure variability (BPV) has been reported to relate with cerebral small vessel disease, but the impact of 24-h BPV on the total MRI cSVD burden and its progression in inpatients with cerebrovascular disease has not been investigated yet. Methods: We enrolled inpatients with cerebrovascular disease, who underwent the 24-h ambulatory blood pressure monitoring (ABPM) and the brain MRI scan at baseline and had the follow-up brain MRI images stored in the clinical information system of our hospital. BPV was quantified by the calculation of standard deviation (SD), coefficient of variation (CV), weighted standard deviation (wSD) of blood pressure record. We evaluated the total cSVD score on baseline MRI and the MRI followed-up to obtain the total burden of cSVD. The cSVD burden progression was estimated through the comparison of the total cSVD score on the two MRIs. Results: A total of 140 patients with an average age of 65.6 years were finally enrolled, 82.9% (116/140) of whom had one or more cSVD markers. After a median of 4.4 years follow-up, cSVD score progression were found in 50.7% (71/140) of the patients. Both SD and CV of SBP and DBP during 24-h and daytime as well as the SBP wSD differed significantly among different total cSVD score groups. The SBP SD and CV during 24-h and daytime, the SBP SD in nighttime, the DBP SD and CV during the daytime were significantly higher in the cSVD progression group than those in the cSVD no-progression group. The SBP wSD and the DBP wSD were significantly higher in the cSVD progression group than those in the cSVD no-progression group. Logistic regression analyses revealed that daytime SBP SD and SBP wSD were independent risk factors for total cSVD burden [daytime SBP SD: OR = 1.628, 95% CI = 1.105-2.398 (per 5 mmHg increase in SD), P = 0.014; SBP wSD: OR = 2.248, 95% CI = 1.564-3.230 (per 5 mmHg increase in wSD), P < 0.001)] and SBP wSD was a significant predictor for cSVD progression [OR = 2.990, 95% CI = 1.053-8.496 (per 5 mmHg increase in wSD), P = 0.040]. Conclusion: Higher BPV were significantly related with total cSVD burden in inpatients with cerebrovascular disease. SBP SD during daytime and SBP wSD were independent risk factor for total cSVD burden and SBP wSD was an predictive factor for cSVD progression.

Acute Toxicity and Triphasic Waves-The Example of Cefepime

PURPOSE

Triphasic waves (TWs) have been associated with a host of medication toxicities, and cefepime has emerged recently as a frequently encountered offending agent. This investigation aims to evaluate cefepime-induced encephalopathy and to report the associated clinical, EEG expression with TWs, and the radiologic findings.

METHODS

A retrospective multicenter observational study examining adult patients with cefepime-induced encephalopathy with generalized periodic discharges on either routine or continuous EEG between January 2014 and January 2020. Clinical, electrographic, and radiologic data were collected. Patients in whom cefepime was not the sole causative factor for their encephalopathy were excluded.

RESULTS

Twenty-seven patients with cefepime-induced encephalopathy marked by generalized periodic discharges with triphasic morphology were identified at both centers, whereas no patients were presenting with generalized periodic discharges without TWs. Patients had a median age of 63 years (interquartile range, 56-73). Fifty-six percent of the cohort (15 patients) were <65 years of age. Eighteen patients (67%) had either acute or chronic kidney impairment (either acute kidney injury or chronic kidney disease or both), whereas 81% had preexisting white matter disease on brain imaging. Of these, 14 patients (51%) were classified as either moderate or severe. In the majority of the patients, TWs were either state-dependent or stimulus-sensitive, and in one third of them presented only as stimulus-induced pattern. All patients improved with discontinuation of cefepime.

CONCLUSIONS

Cefepime toxicity should be considered in the differential diagnosis in encephalopathic patients with TWs. The presence of preexisting white matter disease in these patients should heighten the degree of suspicion, especially in younger patients and patients without renal dysfunction.

Is there an association between orthostatic hypotension and cerebral white matter hyperintensities in older people? The Irish longitudinal study on ageing

Introduction

Orthostatic Hypotension (OH) is an abnormal drop in blood pressure (BP) that occurs following orthostatic challenge. OH is associated with increased risk of falls, cognitive impairment and death. White Matter Hyperintensities (WMH) on MR Brain are associated with vascular risk factors such as hypertension, diabetes and age. We examined whether extent White matter intensities were associated with presence of OH detected in a community dwelling population of older people.

Methods

Individuals from the MR sub-study of the Irish Longitudinal Study of Ageing underwent a 3 Tesla MR Brain scan to assess WMH severity (Schelten’s Score). The scans were performed during the Wave 3 TILDA health assessment phase when the subjects also underwent assessment for OH with an active stand protocol. Data was analysed for association between WMH and vascular risks and orthostatic change in BP 10 second intervals during the OH evaluation.

Results

440 subjects were investigated; median age 72 years (65–92 years) and 228 (51.5%) female. Range of Scheltens’ Scores was 0–32. Mean score was 9.72 (SD 5.87). OH was detected in 68.4% (301). On linear regression, positive associations were found between Scheltens’ Score and age, hypertension, prior history of stroke and TIA, and with OH at 30, 70, 90 and 100 seconds following standing (p < 0.05, O.R. 1.9–2.5).

Conclusion

WMD is associated with OH detected at multiple time points using active stand in community dwelling older subjects. Further research is necessary to evaluate the direction of this association.

Association between Pulse Pressure and Onset of Dementia in an Elderly Korean Population: A Cohort Study

Objective: There is paucity of studies on the association between pulse pressure and the development of dementia, although this association has already been established. This study aimed at investigating the association between pulse pressure and the onset of dementia. Methods: We used the South Korean National Health Insurance Service claims cohort data to select 149,663 patients without dementia aged ≥60 years. We calculated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for dementia using Cox proportional hazard models according to a pulse pressure classification (<50, 50-59, 60-69, 70-79, 80-89, or 90+). Results: Compared to women with pulse pressure <50, those with pulse pressures of 50-59, 60-69, and 90+ had higher HRs for dementia (1.14, 1.22, and 1.03, respectively). These associations were particularly strong in those on Medicaid insurance and from rural regions. However, there were no statistically significant results among men. Conclusions: A higher pulse pressure was associated with an elevated risk of dementia in women aged >60 years, particularly those on Medicaid and from rural regions, possibly due to their inability to access hypertension and other medical treatment. The establishment of dementia indicators will help to guide future health policies for the prevention of dementia.

Natural history of the late-onset phenotype of Fabry disease due to the p.F113L mutation

BACKGROUND

The common GLA gene mutation p.F113L causes late-onset phenotype of Fabry disease (FD) with predominant cardiac manifestations. A founder effect of FD due to this mutation was found in the Portuguese region of Guimarães. Our study aims to deepen the knowledge on the natural history of this late-onset variant.

METHODS

203 consecutive adult Fabry patients with p.F113L mutation (79 males; mean age 46 ± 18 years), from this region, were submitted at baseline to a predefined diagnostic protocol. The occurrence of FD manifestations was analyzed in each decade of age in both genders.

RESULTS

In males, left ventricular hypertrophy (40.2%) and late gadolinium enhancement (21.4%) arose over 30 years; heart failure (HF) (21.9%), ventricular tachycardia (8.9%) and conduction disorders over 40 years; and bifascicular (13.1%) and complete atrioventricular blocks (5.9%) beyond 50 years of age. Cardiac manifestations occurred more commonly and 1-2 decades earlier in males; their frequency increased with age. Septum and posterior wall thickness, LV mass, QRS interval duration and pro-BNP levels increased with age in both genders. Mean survival free from HF (64 ± 1 vs. 76 ± 2 years) and pacemaker (71 ± 2 vs. 86 ± 1 years) was higher in females (p < .001). Albuminuria A2/A3 (33.7%), brain white matter lesions (50.3%) and sensorineural deafness (44.7%) arose before 30 years of age in both genders, increasing with age. Renal failure and stroke were rare. Lysosomal inclusions were demonstrated in podocytes of patients with proteinuria.

CONCLUSION

This study improves the knowledge on natural history of late-onset variants of FD, carrying major impact on clinical decisions and guidelines.

Is there an association between the parameters of arterial stiffness and tinnitus?

Background: Increasing arterial stiffness is associated with atherosclerosis and there is an association between atherosclerosis and tinnitus may occur.Objectives: The aim of this study was to investigate the relationship between arterial stiffness and tinnitus using the central pulse-wave analysis method.Methods: This prospective, single center study included 98 participants, comprising 49 patients diagnosed with subjective idiopathic tinnitus (Group 1) and a control group of 49 healthy subjects (Group 2). The Mobil-O-Graph 24 h Pulse wave analysis (PWA) Monitor (I.E.M. GmbH, Stolberg, Germany) was used to determine the arterial stiffness and cardiovascular hemodynamic parameters. Central pulse pressure (CPP), Augmentation index and pulse wave velocity (PWV) were obtained with the device.Results: No statistically significant difference was determined between Groups in respect of age, smoking and hypertension (p > .05). Statistically significantly higher Central Pulse Pressure (CPP) values and pulse wave velocity were higher in Group 1 compared to the control group (p < .005). No statistical variation was detected in terms of the augmentation index (18.5 ± 11.3 vs 16.7 ± 10.3, p = .543).Conclusion: Our results marked that arterial stiffness is associated with tinnitus. The relationship was examined via oscillometric method, which is simple to perform and has been recommended in guidelines for the determination of cardiovascular event risk.

Abnormal blood pressure circadian rhythms are relevant to cerebral infarction and Leukoaraiosis in hypertensive patients

BACKGROUND

To investigate the relationships between blood pressure (BP) circadian rhythms and acute cerebral infarction (ACI), silent cerebral infarction (SCI) and the severity of leukoaraiosis in hypertensive patients.

METHODS

A retrospective case-control study was performed among hypertensive patients with 24-h ambulatory blood pressure monitoring (ABPM) and cranial magnetic resonance imaging (MRI).

RESULTS

A total of 1267 patients were enrolled. Lower nocturnal blood pressure (BP) decreases were observed in ACI patients than in controls (3.3% vs 8.2%, P<0.001). Reverse-dipper pattern (RD) and non-dipper pattern (ND) were found to be independent risk factors for ACI. In ACI patients, both RD and ND BP circadian rhythms were revealed to be independent risk factors for moderate-severe leukoaraiosis. In addition, in SCI patients, RD (OR = 1.7, 95% CI, 0.9-3.0; P = 0.047) or extreme-dipper pattern (ED) (OR = 2.9, 95% CI, 1.2-7.0; P = 0.015) were found to be independent risk factors for moderate-severe leukoaraiosis. Moreover, the greater the severity of leukoaraiosis was, the higher the ratio of abnormal BP circadian rhythms.

CONCLUSION

RD and ND BP circadian rhythms might not only be relevant to the onset of ACI but also correlate with the severity of leukoaraiosis. Thus, when modulating BP with antihypertensive drugs, the BP circadian rhythms, and not merely the BP level, should warrant more attention.

Midlife Smaller and Larger Infarctions, White Matter Hyperintensities, and 20-Year Cognitive Decline: A Cohort Study

BACKGROUND

Smaller (<3-mm) infarctions are associated with stroke and stroke mortality, but relationships with cognitive decline are unknown.

OBJECTIVE

To characterize the relationships of smaller, larger, and both smaller and larger infarctions in middle age with 20-year cognitive decline.

DESIGN

Longitudinal cohort study.

SETTING

Two ARIC (Atherosclerosis Risk in Communities) study sites with magnetic resonance imaging data (1993 to 1995) and up to 5 cognitive assessments over 20 years.

PARTICIPANTS

Stroke-free participants aged 50 years or older.

MEASUREMENTS

Infarctions were categorized as none, smaller only, larger only (3 to 20 mm), or both smaller and larger. Global cognitive Z scores were derived from 3 cognitive tests administered up to 5 times. Mixed-effects models estimated adjusted associations between infarctions and cognitive decline. Results are the average difference in standardized cognitive decline associated with infarctions versus no infarctions.

RESULTS

Among 1884 participants (mean age, 62 years; 60% women; 50% black), 1611 (86%) had no infarctions, 50 (3%) had smaller infarctions only, 185 (10%) had larger infarctions only, and 35 (2%) had both. Participants with both smaller and larger infarctions had steeper cognitive decline by more than half an SD (difference, -0.57 SD [95% CI, -0.89 to -0.26 SD]) compared with those who had no infarctions. Amounts of cognitive decline associated with only smaller infarctions and only larger infarctions were similar and were not statistically different from that associated with no infarctions.

LIMITATION

Few participants had only smaller infarctions or both smaller and larger infarctions, and the data lacked counts of smaller infarctions and volumes of white matter hyperintensities.

CONCLUSION

The substantial cognitive decline from middle age associated with having both smaller and larger infarctions, but not larger infarctions alone, suggests that the combination of smaller and larger infarctions may escalate risk for cognitive decline later in life in stroke-free persons.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Associations of decision making abilities with blood pressure values in older adults

OBJECTIVES

Decision making, key to successful aging, has implications for financial success, physical health, and well being. While poor decision making has been linked with increased risk of mortality, age-related cognitive decline, and dementia, less is known regarding its associations with chronic disease indicators. We investigated the associations of decision making with blood pressure (BP) values [i.e., SBP, mean arterial pressure (MAP), and pulse pressure (PP), separately] in a community-based cohort study of aging.

METHODS

Participants were 908 nondemented older adults (age ∼81 years; 75% women) from the Rush Memory and Aging Project. Decision making was measured using questions designed to simulate materials used in financial and healthcare settings in the real world and yielded a total score and domain-specific health and financial decision making scores. Two seated and one standing BP measurement were taken with all three contributing to average SBP, MAP that is, [SBP + (2 × DBP)]/3, and PP, that is, SBP - DBP. Participants were queried about hypertension status and antihypertension medications were visually inspected and coded. Participants also underwent medical history and cognitive assessments.

RESULTS

In separate multivariable linear regression models, total decision making scores were inversely associated with SBP, MAP, and PP after adjusting for age, sex, education, antihypertension medication use, diabetes, and cumulative cardiovascular disease burden (P values = 0.03). Decision making remained associated with these BP values after additional adjustment for global cognition.

CONCLUSION

Poorer decision making is associated with higher BP values in nondemented older adults.

Measurement of Socioeconomic Position in Research on Cardiovascular Health Disparities in Korea: A Systematic Review

OBJECTIVES

The validity of instruments measuring socioeconomic position (SEP) has been a major area of concern in research on cardiovascular health disparities. The purpose of this systematic review is to identify the current status of the methods used to measure SEP in research on cardiovascular health disparities in Korea and to provide directions for future research.

METHODS

Relevant articles were obtained through electronic database searches with manual searches of reference lists and no restriction on the date of publication. SEP indicators were categorized into compositional, contextual, composite, and life-course measures.

RESULTS

Forty-eight studies published from 2003 to 2018 satisfied the review criteria. Studies utilizing compositional measures mainly relied on a limited number of SEP parameters. In addition, these measures hardly addressed the time-varying and subjective features of SEP. Finding valid contextual measures at the organizational, community, and societal levels that are appropriate to Korea's context remains a challenge, and these are rarely modeled simultaneously. Studies have rarely focused on composite and life-course measures.

CONCLUSIONS

Future studies should develop and utilize valid compositional and contextual measures and appraise social patterns that vary across time, place, and culture using such measures. Studies should also consider multilevel influences, adding a focus on the interactions between different levels of intertwined SEP factors to advance the design of research. More attention should be given to composite and life-course measures.

Small vessel disease to subcortical dementia: a dynamic model, which interfaces aging, cholinergic dysregulation and the neurovascular unit

Background

Small vessels have the pivotal role for the brain’s autoregulation. The arteriosclerosis-dependent alteration of the brain perfusion is one of the major determinants in small vessel disease. Endothelium distress can potentiate the flow dysregulation and lead to subcortical vascular dementia (sVAD). sVAD increases morbidity and disability. Epidemiological studies have shown that sVAD shares with cerebrovascular disease most of the common risk factors. The molecular basis of this pathology remains controversial.

Purpose

To detect the possible mechanisms between small vessel disease and sVAD, giving a broad vision on the topic, including pathological aspects, clinical and laboratory findings, metabolic process and cholinergic dysfunction.

Methods

We searched MEDLINE using different search terms (“vascular dementia”, “subcortical vascular dementia”, “small vessel disease”, “cholinergic afferents”, etc). Publications were selected from the past 20 years. Searches were extended to Embase, Cochrane Library, and LILIACS databases. All searches were done from January 1, 1998 up to January 31, 2018.

Results

A total of 560 studies showed up, and appropriate studies were included. Associations between traditional vascular risk factors have been isolated. We remarked that SVD and white matter abnormalities are seen frequently with aging and also that vascular and endothelium changes are related with age; the changes can be accelerated by different vascular risk factors. Vascular function changes can be heavily influenced by genetic and epigenetic factors.

Conclusion

Small vessel disease and the related dementia are two pathologies that deserve attention for their relevance and impact in clinical practice. Hypertension might be a historical problem for SVD and SVAD, but low pressure might be even more dangerous; CBF regional selective decrease seems to be a critical factor for small vessel disease-related dementia. In those patients, endothelium damage is a super-imposed condition. Several issues are still debatable, and more research is needed.

Disparities in Diffuse Cortical White Matter Integrity Between Socioeconomic Groups

There is a growing literature demonstrating a link between lower socioeconomic status (SES) and poorer neuroanatomical health, such as smaller total and regional gray and white matter volumes, as well as greater white matter lesion volumes. Little is known, however, about the relation between SES and white matter integrity. Here we examined the relation between SES and white matter integrity of the brain’s primary cortical regions, and evaluated potential moderating influences of age and self-identified race. Participants were 192 neurologically intact, community-dwelling African American and White adults (mean age = 52 years; 44% male, 60% White, low SES = 52%) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging. Diffusion tensor imaging was used to estimate regional fractional anisotropy (FA) to quantify the brain’s white matter integrity and trace to capture diffusivity. Multiple regression analyses examined independent and interactive associations of SES, age, and race with FA of the frontal, temporal, parietal, and occipital lobes bilaterally. Sensitivity analyses assessed the influence of several biopsychosocial risk factors on these associations. Exploratory analyses examined these relations with trace and using additional SES indicators. Results indicated there were no significant interactions of SES, age, and race for any region. Individuals with low SES had lower FA in all regions, and higher trace in the right and left frontal, right and left temporal, and left occipital lobes. Findings remained largely unchanged after inclusion of sensitivity variables. Older age was associated with lower FA and greater trace for all regions, except for the right temporal lobe with FA. No main effects were found for race in FA, and Whites had higher trace values in the parietal lobes. Novel findings of this study indicate that relative to the high SES group, low SES was associated with poorer white matter integrity and greater diffusivity. These results may, in part, reflect exposures to various biopsychosocial risk factors experienced by those of lower SES across the lifespan, and may help explain the preponderance of cognitive and functional disparities between socioeconomic groups.

Brain MRI findings related to Alzheimer's disease in older African American adults

Although a substantial body of research has identified brain MRI measures as important markers of Alzheimer's disease (AD) risk, progression, and treatment response, most of that research has been performed in non-Hispanic white American populations, leading to questions about the utility of the brain MRI measures among individuals of other races or ethnicities. African American individuals in particular are under-represented in AD research, and may exhibit differences in prevalence of AD risk factors, prevalence of AD, incidence of AD, the clinical course of cognitive decline, and AD neuropathology, each of which could influence the utility of brain MRI markers. Unfortunately, while current evidence suggests that African Americans exhibit poorer brain health late in life based on brain MRI measurements, several other aspects of brain MRI markers in this population are unclear, including trajectories of brain MRI markers leading up to old age, relationships between traditional brain health risk factors and brain MRI findings, and the status of brain MRI markers as correlates of cognitive impairment. This unclear state of affairs highlights the urgency of future research in which large numbers of older African American adults contribute longitudinal brain MRI measurements concurrent with clinical, cognitive, and molecular biomarker measurements, ideally in the context of AD preventive or therapeutic trials.

Activated Microglia in Cortical White Matter Across Cognitive Aging Trajectories

Activation of microglia, the primary mediators of inflammation in the brain, is a major component of gliosis and neuronal loss in a number of age-related neurodegenerative disorders, such as Alzheimer’s disease (AD). The role of activated microglia in white matter, and its relationship with cognitive decline during aging are unknown. The current study evaluated microglia densities in the white matter of postmortem specimens from cognitively normal young adults, cognitively normal older adults, and cognitive “SuperAgers,” a unique group of individuals over age 80 whose memory test scores are at a level equal to or better than scores of 50-to-65-year-olds. Whole hemisphere sections from cognitively normal old, young, and “SuperAgers” were used to quantify densities of human leukocyte antigen-D related (HLA-DR)-positive activated microglia underlying five cortical regions. Statistical findings showed a significant main effect of group on differences in microglia density where cognitively normal old showed highest densities. No difference between SuperAgers and young specimens were detected. In two autopsied SuperAgers with MRI FLAIR scans available, prominent hyperintensities in periventricular regions were observed, and interestingly, examination of corresponding postmortem sections showed only sparse microglia densities. In conclusion, activated microglia appear to respond to age-related pathologic changes in cortical white matter, and this phenomenon is largely spared in SuperAgers. Findings offer insights into the relationship between white matter neuroinflammatory changes and cognitive integrity during aging.

Asymptomatic Cerebral Small Vessel Disease: Insights from Population-Based Studies

Cerebral small vessel disease (CSVD) is a common group of neurological conditions that confer a significant burden of morbidity and mortality worldwide. In most cases, CSVD is only recognized in its advanced stages once its symptomatic sequelae develop. However, its significance in asymptomatic healthy populations remains poorly defined. In population-based studies of presumed healthy elderly individuals, CSVD neuroimaging markers including white matter hyperintensities, lacunes, cerebral microbleeds, enlarged perivascular spaces, cortical superficial siderosis, and cerebral microinfarcts are frequently detected. While the presence of these imaging markers may reflect unique mechanisms at play, there are likely shared pathways underlying CSVD. Herein, we aim to assess the etiology and significance of these individual biomarkers by focusing in asymptomatic populations at an epidemiological level. By primarily examining population-based studies, we explore the risk factors that are involved in the formation and progression of these biomarkers. Through a critical semi-systematic review, we aim to characterize “asymptomatic” CSVD, review screening modalities, and draw associations from observational studies in clinical populations. Lastly, we highlight areas of research (including therapeutic approaches) in which further investigation is needed to better understand asymptomatic CSVD.

Blood pressure, glycemic control, and white matter hyperintensity progression in type 2 diabetics

OBJECTIVE

To determine whether higher blood pressure mean (BPM) or hemoglobin A1c is associated with progression of white matter hyperintensity (WMH) on MRI in patients with type 2 diabetes, and whether intensive blood pressure or glycemic control can reduce that progression.

METHODS

We performed a secondary analysis of the Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes (ACCORD MIND) research materials. The primary outcome is change in WMH volume (ΔWMH) between a baseline and month-40 MRI, and the primary predictor is BPM and A1c between the MRIs. Additional analyses compared ΔWMH in the intensive vs standard glycemic control randomization arms (n = 502) and intensive vs standard blood pressure control randomization arms (n = 314).

RESULTS

Higher systolic BPM, but not diastolic BPM or A1c, was associated with WMH progression. The ΔWMH in tertiles of increasing systolic BPM (115 ± 4, 127 ± 3, and 139 ± 6 mm Hg) was 0.7, 0.9, and 1.2 cm³ (p < 0.001). ΔWMH was lower in the intensive vs standard blood pressure control randomization arm (ΔWMH = 0.67 ± 0.95 vs 1.16 ± 1.13 cm³, p < 0.001), but there was no difference in the glycemic control arms (p = 0.917).

CONCLUSION

In ACCORD MIND, higher systolic blood pressure was associated with WMH progression. The intensive blood pressure control intervention reduced this progression. Comorbid diabetes and hypertension has synergistic deleterious properties that increase the risk of micro- and macrovascular complications. These results provide further support for an aggressive approach to blood pressure control in type 2 diabetics.

Perspectives on ethnic and racial disparities in Alzheimer's disease and related dementias: Update and areas of immediate need

Alzheimer's disease and related dementias (ADRDs) are a global crisis facing the aging population and society as a whole. With the numbers of people with ADRDs predicted to rise dramatically across the world, the scientific community can no longer neglect the need for research focusing on ADRDs among underrepresented ethnoracial diverse groups. The Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART; alz.org/ISTAART) comprises a number of professional interest areas (PIAs), each focusing on a major scientific area associated with ADRDs. We leverage the expertise of the existing international cadre of ISTAART scientists and experts to synthesize a cross-PIA white paper that provides both a concise "state-of-the-science" report of ethnoracial factors across PIA foci and updated recommendations to address immediate needs to advance ADRD science across ethnoracial populations.

Vascular Risk Factors and Findings on Brain MRI of Elderly Adult American Indians: The Strong Heart Study

BACKGROUND

Clinical stroke is prevalent in American Indians, but the risk factors for cerebrovascular pathology have not been well-studied in this population. The purpose of this study was to correlate abnormalities on brain magnetic resonance imaging (MRI) with clinical risk factors in a cohort of elderly American Indians.

METHODS

Brain MRI scans from 789 participants of the Strong Heart Study were analyzed for infarcts, hemorrhage, white matter disease, and measures of cerebral atrophy including ventricular and sulcal grade and total brain volume. Clinical risk factors included measures of hypertension, diabetes, and high levels of low-density lipoprotein (LDL) cholesterol. Regression models adjusted for potential confounders were used to estimate associations between risk factors and brain MRI outcomes.

RESULTS

-Hypertension was associated with the presence of infarcts (p = 0.001), ventricle enlargement (p = 0.01), and increased white matter hyperintensity volume (p = 0.01). Diabetes was associated with increased prevalence of cerebral atrophy (p < 0.001), ventricular enlargement (p = 0.001), and sulcal widening (p = 0.001). High LDL was not significantly associated with any of the measured cranial imaging outcomes.

CONCLUSIONS

This study found risk factors for cerebrovascular disease in American Indians similar to those seen in other populations and provides additional evidence for the important roles of hypertension and diabetes in promoting cerebral infarcts and brain atrophy, respectively.

Age and recurrent stroke are related to the severity of white matter hyperintensities in lacunar infarction patients with diabetes

Background and purpose

White matter hyperintensities (WMH) is identified as a marker of cerebral small vessel diseases and is a major contributor to cognitive impairment, depression, gait disturbance, and urinary incontinence. However, the risk factors for WMH in patients with type 2 diabetes mellitus (T2DM) has not been well explored. Thus, in this study, we aimed to investigate the relationship between the severity of WMH and vascular risk factors in lacunar infarction patients with T2DM.

Methods

Consecutive lacunar infarction patients with T2DM were recruited in this cross-sectional study. Paraventricular WMH (P-WMH) and deep WMH (D-WMH) were separately scored by the Fazekas scale, and classified into two categories by the severity. Vascular risk factors and clinical features were compared between the mild and severe WMH. Multiple logistic regression analysis was used to determine the relationship between severity of WMH and vascular risk factors.

Results

A total of 327 participants aged 34–91 years were enrolled in this study. Compared with the patients with mild P-WMH, the patients with severe P-WMH had higher age (P=0.031), higher proportion of hypertension (P=0.042) and stroke (P<0.001). Levels of TG, LDL, and HbA1c were significantly higher in patients with mild P-WMH. Compared with the patients with mild D-WMH the patients with severe D-WMH had higher age and hyperhomocysteinemia (HCY) level (P<0.001), higher proportion of hyperlipidemia (P=0.008), and stroke (P<0.001). Multivariable logistic regression analyses showed that higher age and recurrent stroke were independently related to severe P-WMH and D-WMH in lacunar infarction patients with T2DM.

Conclusions

Age and recurrent stroke are related to the severity of P-WMH and D-WMH in lacunar infarction patients with T2DM.

Aortic stiffness, pressure and flow pulsatility, and target organ damage

Measures of aortic stiffness and pressure and flow pulsatility have emerged as correlates of and potential contributors to cardiovascular disease, dementia, and kidney disease. Higher aortic stiffness and greater pressure and flow pulsatility are associated with excessive pulsatile load on the heart, which increases mass and reduces global longitudinal strain of the left ventricle. Excessive stiffness and pulsatility are also associated with microvascular lesions in high-flow organs, such as the brain and kidney, suggesting that small vessels in these organs are damaged by pulsatility. This brief review will summarize evidence relating aortic stiffness to cardiovascular, brain, and kidney disease.

Detection of white matter lesion regions in MRI using SLIC0 and convolutional neural network

BACKGROUND AND OBJECTIVE

White matter lesions are non-static brain lesions that have a prevalence rate up to 98% in the elderly population. Because they may be associated with several brain diseases, it is important that they are detected as soon as possible. Magnetic Resonance Imaging (MRI) provides three-dimensional data with the possibility to detect and emphasize contrast differences in soft tissues, providing rich information about the human soft tissue anatomy. However, the amount of data provided for these images is far too much for manual analysis/interpretation, representing a difficult and time-consuming task for specialists. This work presents a computational methodology capable of detecting regions of white matter lesions of the brain in MRI of FLAIR modality. The techniques highlighted in this methodology are SLIC0 clustering for candidate segmentation and convolutional neural networks for candidate classification.

METHODS

The methodology proposed here consists of four steps: (1) images acquisition, (2) images preprocessing, (3) candidates segmentation and (4) candidates classification.

RESULTS

The methodology was applied on 91 magnetic resonance images provided by DASA, and achieved an accuracy of 98.73%, specificity of 98.77% and sensitivity of 78.79% with 0.005 of false positives, without any false positives reduction technique, in detection of white matter lesion regions.

CONCLUSIONS

It is demonstrated the feasibility of the analysis of brain MRI using SLIC0 and convolutional neural network techniques to achieve success in detection of white matter lesions regions.

Lifetime discrimination burden, racial discrimination, and subclinical cerebrovascular disease among African Americans

OBJECTIVE

Explore interactive relations of lifetime discrimination burden and racial discrimination-chronic stressors among African Americans (AAs)-and age with MRI-assessed white matter lesion volume (WMLV), a prognostic indicator of poor clinical brain health outcomes.

METHOD

AAs (N = 71; 60.6% female, mean age = 50) participating in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study underwent quantitative magnetic resonance imaging coded for WMLV. Participants self-reported lifetime discrimination burden and racial discrimination approximately 5 years earlier. Multivariable regression models assessed interactions of linear and quadratic effects of discrimination and age with WMLV adjusted for sex and socioeconomic status.

RESULTS

Findings revealed significant interactive relations of age and (a) quadratic, lifetime discrimination burden, B = .05, p = .014, ηpartial2 = .092, and (b) quadratic, racial discrimination, B = .03, p = .001, ηpartial2 = .155, with WMLV. Among older AA, increases in lifetime discrimination burden and racial discrimination were associated with increases in WMLV (ps < .03); in younger AA, decreasing levels of racial discrimination were related to increases in WMLV (p = .006).

CONCLUSIONS

Among older AA, as lifetime discrimination burden and racial discrimination increased, so did WMLV. However, in younger AA, decreases in racial discrimination were associated with increased WMLV. Elucidation of complex mechanistic underpinnings, including potentially differential impacts of the acknowledgment versus suppression or underreporting of discriminatory experiences, among AA of different age cohorts, is critical to understanding the present pattern of findings. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Deep chronic microvascular white matter ischemic change as an independent predictor of acute brain infarction after thoracic aortic replacement

BACKGROUND

Postoperative brain injury is a cause of mortality and morbidity in patients who undergo thoracic aortic replacement. Chronic microvascular white matter ischemic change (WMIC) has been shown to be associated with acute brain infarction in the general population. WMIC has also been shown to be an independent predictor of non-focal neurocognitive changes, generalized seizures, and temporary neurologic dysfunction in patients who undergo thoracic aortic replacement. The aim of this study is to determine if WMIC is a risk factor for acute brain infarction in patients who undergo thoracic aortic replacement.

METHODS

A case-control study of patients who underwent thoracic aortic replacement between 2001 and 2014 were reviewed for neurological changes after surgery and acute brain infarction on postoperative diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI). Patients with neurological changes were matched with control patients who underwent thoracic aortic replacement and had postoperative neurological symptoms without acute brain infarctions. Acute infarction was re-assessed by reviewing DWI sequences on postoperative MRI. WMIC was assessed on FLAIR and T2WI sequences on both preoperative and postoperative MRI. Logistic regression was performed assessing the relationship of WMIC and acute ischemic infarction.

RESULTS

5171 patients underwent thoracic aortic replacement; 179 had postoperative neurological changes, and of those 53 patients had acute brain infarction on postoperative DWI. Patients with deep WMIC were more likely to have acute DWI infarctions after thoracic aortic replacement (P = 0.023).

CONCLUSION

Our matched retrospective case-controlled study shows deep WMIC to be a predictor of acute brain infarction on DWI after thoracic aortic replacement.

Twenty-four-hour ambulatory blood pressure variability is associated with total magnetic resonance imaging burden of cerebral small-vessel disease

Background

Lacunae, brain atrophy, white matter hyperintensity, enlarged perivascular space and microbleed are magnetic resonance imaging (MRI) markers of cerebral small-vessel disease (cSVD). Studies have reported that higher blood pressure variability (BPV) predicted cardiovascular risk in hypertensive patients; however, the association between BPV and the total MRI burden of cSVD has not been investigated. In this study, we aimed to explore this relationship between BPV and cSVD MRI burden.

Methods

We prospectively recruited patients who attended our hospital for annual physical examination. Twenty-four-hour ambulatory BP monitoring was performed using an automated system. BPV was quantified by SD, weighted SD, and coefficient of variation. One point was awarded for the presence of each marker, producing a score between 0 and 5. Spearman correlation and ordinal logistic regression analyses were used to test the relationship between BPV and total cSVD MRI burden.

Results

A total of 251 subjects with an average age of 68 years were enrolled in this study, and 52.6% were male; 163 (64.94%) had one or more markers of cSVD. Correlation analysis indicated that higher systolic BP (SBP) levels and BPV metrics of SBP were positively related to higher cSVD burden. Ordinal logistic regression analyses demonstrated that higher SBP levels and SBP variability were independent risk factors for cSVD. There were no significant differences in 24-hour, day and night diastolic BP levels or BPV metrics of diastolic BP among the five subgroups.

Conclusion

Twenty-four-hour, day and night SBP levels and SBP variability were positively related to cSVD burden. Higher SBP levels and SBP variability were independent risk factors for cSVD.

Visit-to-Visit Blood Pressure Variability and Alzheimer's Disease: Links and Risks

While hypertension has been shown to be a risk factor for vascular dementia, several studies have also demonstrated that hypertension also increases the risk of Alzheimer's disease (AD). Although the relationship between visit-to-visit blood pressure variability (VVV) and cognitive impairment, including AD, have been provided, the mechanisms remain poorly understood. This review paper focuses on the relationship of VVV with AD and summarizes the pathophysiology underlying that relationship, which appears to be mediated by arterial stiffness.

Pulse wave velocity differs between ulcerative colitis and chronic kidney disease

BACKGROUND

We hypothesized that a reversal of the physiological stiffness gradient, previously reported in end-stage renal disease, begins in the early stages of chronic kidney disease (CKD) and that chronic inflammation produces a different arterial phenotype in patients with ulcerative colitis (UC).

OBJECTIVES

To assess the extent of arterial stiffening in the central (carotid-femoral pulse wave velocity, cf.-PWV) and peripheral arteries (carotid-radial pulse wave velocity, cr-PWV) and to explore the determinants of the stiffness gradient in UC and in CKD.

METHODS

We enrolled 45 patients with UC, 45 patients with stage 3-4 CKD and 45 matched controls.

RESULTS

Despite the comparable cf.-PWV, the cr-PWV was higher in patients with UC than in those with CKD (median: 8.7 vs. 7.5m/s; p<0.001) and, consequently, the PWV ratio was lower (median: 0.97 vs. 1.12; p<0.001). In patients with CKD a stiffness mismatch was reported starting from stage 3B. The PWV ratio was associated with age and C-reactive protein (beta: 0.08 z-score, 95%CI 0.02-0.14; p=0.01) or active disease (beta: 0.43 z-score, 95%CI 0.003-0.857; p=0.048) in patients with UC and with age and glomerular filtration rate (beta: -0.56 z-score, 95%CI -1.05 to -0.07; p=0.02) in patients with CKD.

CONCLUSIONS

The arterial phenotype differed between UC and CKD. The reversal of the arterial stiffness gradient is evident in CKD patients starting from stage 3B but not in patients with UC and comparable cf.-PWV. In patients with UC, the stiffness of both elastic and muscular arteries is increased as a consequence of inflammation.