Risk Factors, Lifestyle Behaviors, and Vascular Brain Health

Although a relationship between traditional cardiovascular risk factors and stroke has long been recognized, these risk factors likely play a role in other aspects of brain health. Clinical stroke is only the tip of the iceberg of vascular brain injury that includes covert infarcts, white matter hyperintensities, and microbleeds. Furthermore, an individual’s risk for not only stroke but poor brain health includes not only these traditional vascular risk factors but also lifestyle and genetic factors. The purpose of this narrative review is to summarize the state of the evidence on traditional and nontraditional vascular risk factors and their contributions to brain health. Additionally, we will review important modifiers that interact with these risk factors to increase, or, in some cases, reduce risk of adverse brain health outcomes, with an emphasis on genes and biomarkers associated with Alzheimer disease. Finally, we will consider the importance of social determinants of health in brain health outcomes.

Contribution of Inflammation and Hypoperfusion to White Matter Hyperintensities-Related Cognitive Impairment

White matter hyperintensities (WMHs) of presumed vascular origin are one of the most important neuroimaging markers of cerebral small vessel disease (CSVD), which are closely associated with cognitive impairment. The aim of this study was to elucidate the pathogenesis of WMHs from the perspective of inflammation and hypoperfusion mechanisms. A total of 65 patients with WMHs and 65 healthy controls were enrolled in this study. Inflammatory markers measurements [hypersensitive C-reactive protein (hsCRP) and lipoprotein-associated phospholipase A2 (Lp-PLA2)], cognitive evaluation, and pseudocontinuous arterial spin labeling (PCASL) MRI scanning were performed in all the subjects. The multivariate logistic regression analysis showed that Lp-PLA2 was an independent risk factor for WMHs. Cerebral blood flow (CBF) in the whole brain, gray matter (GM), white matter (WM), left orbital medial frontal gyrus [MFG.L (orbital part)], left middle temporal gyrus (MTG.L), and right thalamus (Tha.R) in the patients was lower than those in the controls and CBF in the left triangular inferior frontal gyrus [IFG.L (triangular part)] was higher in the patients than in the controls. There was a significant correlation between Lp-PLA2 levels and CBF in the whole brain (R = −0.417, p < 0.001) and GM (R = −0.278, p = 0.025), but not in the WM in the patients. Moreover, CBF in the MFG.L (orbital part) and the Tha.R was, respectively, negatively associated with the trail making test (TMT) and the Stroop color word test (SCWT), suggesting the higher CBF, the better executive function. The CBF in the IFG.L (triangular part) was negatively correlated with attention scores in the Cambridge Cognitive Examination-Chinese Version (CAMCOG-C) subitems (R = −0.288, p = 0.020). Our results revealed the vascular inflammation roles in WMHs, which may through the regulation of CBF in the whole brain and GM. Additionally, CBF changes in different brain regions may imply a potential role in the modulation of cognitive function in different domains.

Association of total cerebral small vessel disease burden with the cavitation of recent small subcortical infarcts

Background Recent small subcortical infarcts (RSSIs) could evolve into cavitation (lacunes) or non-cavitation (white matter hyperintensities or disappearance) during the chronic period, but the factors involved remain unclear. Purpose To explore the association between total cerebral small vessel disease (CSVD) burden and lesion cavitation. Material and Methods We retrospectively selected 202 inpatients with an isolated RSSI who underwent baseline and follow-up magnetic resonance imaging (median interval = 16.6 months; interquartile range [IQR]=8.2–30.1). Inpatients were divided into cavitation and non-cavitation groups depending on whether a fluid-filled cavity formed. Data including demographic, clinical, and radiological features were collected and analyzed. To determine total CSVD burden, four imaging markers, including lacunes, microbleeds, white matter hyperintensities, and enlarged perivascular spaces, were rated and summed as a final practical score between 0 and 4. Results Overall, 137 (67.8%) patients progressed to cavitation and 65 (32.2%) to non-cavitation. Binary multivariable regression analysis showed that the baseline total CSVD burden ( P = 0.005) and infarct diameter ( P = 0.002) were independent risk factors for cavitation. A severe total burden (scores of 3–4) at baseline was independently related to cavitation ( P = 0.001). Moreover, the total CSVD burden score varied from 2 (IQR=1–3) at baseline to 3 (IQR=2–4) at follow-up. The extent of the increase in total burden was correlated with cavitation ( r = 0.201; P = 0.004). Conclusion Total CSVD burden, both the baseline value and extent of increase, was positively associated with cavitation. RSSIs with severe total CSVD burden at baseline have a greater potential to become cavitated.

White Matter Hyperintensities as a Risk Factor for Ischemic Stroke in Patients With Systemic Lupus Erythematosus

Objective: The occurrence of ischemic stroke in patients with systemic lupus erythematosus (SLE) can cause extended periods of reduced daily activities. However, the risk factors for ischemic stroke in SLE patients are not fully elucidated. Herein, we examined the effect of white matter hyperintensities (WMH) on the occurrence of ischemic stroke in SLE patients.Methods: We analyzed the relationship between WMH burden and ischemic stroke using follow-up brain magnetic resonance imaging (MRI) data of 79 patients with SLE. Of these patients, 16 developed stroke during the observation period. WMH on MRI were classified into periventricular hyperintensities and deep white matter hyperintensities (DWMH), while the lesion extent was graded using the Fazekas scale.Results: Kaplan–Meier curves showed that ischemic stroke events were significantly associated with age at initial brain MRI of ≥40 years (p = 0.015) and history of anti-phospholipid syndrome (p = 0.030). Additionally, ischemic stroke events were significantly associated with a one grade deterioration of periventricular hyperintensities (p = 0.003) and a one grade deterioration of DWMH (p = 0.002). Multivariate analysis using the logistic regression model showed that a one grade deterioration of DWMH was an independent risk factor for ischemic stroke (hazard ratio, 6.0; 95% confidence interval, 1.3–27.4).Conclusions: Although several factors affect the occurrence of ischemic stroke, SLE patients show increased risk of ischemic stroke via development of DWMH. An observation of DWMH deterioration on follow-up brain MRI may be useful for assessing the risk of ischemic stroke in SLE patients.