White Matter Hyperintensity on Cranial Magnetic Resonance Imaging

Age-related white matter change disease predicts long-term cerebrovascular morbidity following carotid endarterectomy

PURPOSE

Cerebrovascular diseases remain a critical focus of medical research due to their substantial impact on global health. Carotid stenosis, often associated with atherosclerosis and advancing age, profoundly affects cerebral blood supply and white matter integrity. This study aims to assess how age-related white matter changes (ARWMC) score, applied to cortex and Basal Ganglia, relates to cardiovascular and cerebrovascular events in patients who underwent carotid endarterectomy (CEA).

METHODS

Ninety patients undergoing CEA with regional anesthesia were prospectively enrolled from January 2012 to January 2022, and a post hoc analysis of patients with preoperative cerebral CT scans were reviewed, stratified by ARWMC score. Survival analysis and multivariate Cox regression were employed to assess time-dependent variables and independent predictors.

RESULTS

A median follow-up of 51 months (Inter-quartile range [IQR [ [38.8-63.2] months) revealed higher ARWMC grades in the basal ganglia independently associated with significantly increased stroke risk (HR=5.070, 95% CI: 1.509-17.031, P=0.009), acute heart failure (HR=19.066, 95% CI: 2.038-178.375, P=0.01), major adverse cardiovascular events (MACE) (HR=2.760, 95% CI: 1.268-6.009, P=0.011), and all-cause mortality (HR=2.497, 95% CI:1.009-6.180, P=0.048). Polyvascular disease and chronic kidney disease emerged as additional predictors of MACE.

CONCLUSION

Higher grades of ARWMC score in the basal ganglia were related to a significant increase in the risk of adverse cardiovascular events, such as stroke, MACE, AHF and all-cause mortality. This study suggests that ARWMC may have potential as a possible predictor of long-term cardio- and cerebrovascular events in patients undergoing CEA.

Aldosterone is Associated With New-onset Cerebrovascular Events in Patients With Hypertension and White Matter Lesions: A Cohort Study

OBJECTIVE

White matter lesions (WMLs) increase the risk of stroke, stroke recurrence, and death. Higher plasma aldosterone concentration (PAC) increases the risk of stroke, acute myocardial infarction, and hypertension. The objective is to evaluate the relationship between PAC and cerebrovascular events in patients with hypertension and WMLs.

METHODS

We conducted a retrospective cohort study that included 1041 participants hospitalized. The outcome was new-onset cerebrovascular events including intracerebral hemorrhage and stroke. A Cox regression model was used to evaluate the relationship between baseline PAC and the risk of cerebrovascular events.

RESULTS

The mean age of participants was 60.9 ± 10.2 years and 565 (53.4%) were males. The median follow-up duration was 42 months (interquartile range: 25-67), and 92 patients experienced new-onset cerebrovascular events. In a multivariate-adjusted model, with PAC as a continuous variable, higher PAC increased the risk of cerebrovascular events; patient risk increased per 1 (hazard ratio [HR: 1.03], 95% confidence interval [CI]: 1.01-1.06, P < .01), per 5 (HR: 1.17, 95% CI: 1.06-1.31, P < .01), and per 10 ng/dL (HR: 1.41, 95%: 1.14-1.75, P < .01) increase in PAC. When PAC was expressed as a categorical variable (quartile: Q1-Q4), patients in Q4 (HR: 2.12, 95% CI: 1.18-3.79, P < .05) exhibited an increased risk of cerebrovascular events compared to Q1. Restrictive spline regression showed a linear association between PAC and the risk of new-onset cerebrovascular events after adjusting for all possible variables.

CONCLUSIONS

Our study identified a linear association between PAC and the risk of new-onset cerebrovascular events in patients with hypertension and WMLs.

Relationship between physical activity and cerebral white matter hyperintensity volumes in older adults with depressive symptoms and mild memory impairment: a cross-sectional study

Introduction

Cerebral white matter hyperintensities (WMHs) are commonly found in the aging brain and have been implicated in the initiation and severity of many central nervous system diseases. Furthermore, an increased WMH volume indicates reduced brain health in older adults. This study investigated the association between WMH volume and physical activity in older adults with depressive symptoms (DS) and mild memory impairment (MMI). Factors associated with the WMH volume were also investigated.

Methods

A total of 57 individuals aged over 65 years with DS and MMI were included in this study. The participants underwent magnetic resonance imaging to quantify WMH volumes. After WMH volume was accumulated, normalized to the total intracranial volume (TIV), the percentage of WMH volume was calculated. In addition, all participants wore a triaxial accelerometer for 2 weeks, and the average daily physical activity and number of steps were measured. The levels of blood biomarkers including cortisol, interleukin-6 (IL-6), brain-derived insulin-like growth factor-1, and brain-derived neurotrophic factor were measured. Motor and cognitive functions were also assessed.

Results

Faster maximum walking speed and longer time spent engaged in moderate physical activity were associated with a smaller percent of WMH volume, whereas higher serum IL-6 levels were associated with a larger percent of WMH volume. The number of steps per day, time spent engaged in low levels of physical activity, cognitive function, and all other measured biomarkers were not significantly associated with percent of WMH volume.

Discussion

Higher blood inflammatory cytokine levels, shorter duration of moderate physical activity, and lower maximum walking speed were associated with a higher percent of WMH volume. Our results provide useful information for maintaining brain health in older adults at a high risk of developing dementia and may contribute to the development of preventive medicine for brain health.

Female Reproductive Events and Subclinical Atherosclerosis of the Brain and Carotid Arteriopathy: the Ohasama Study

AIMS

Few studies have investigated the subclinical atherosclerotic changes in the brain and carotid artery, and in East Asian populations. We sought to investigate whether gravidity, delivery, the age at menarche and menopause and estrogen exposure period are associated with subclinical atherosclerosis of the brain and carotid arteriopathy.

METHODS

This cross-sectional study formed part of a cohort study of Ohasama residents initiated in 1986. Brain atherosclerosis and carotid arteriopathy were diagnosed as white matter hyperintensity (WMH) and lacunae evident on brain magnetic resonance imaging (MRI) and carotid intimal media thickness (IMT) or plaque revealed by ultrasound, respectively. The effect of the reproductive events on brain atherosclerosis and carotid arteriopathy was investigated using logistic regression and general linear regression models after adjusting for covariates.

RESULTS

Among 966 women aged ≥ 55 years in 1998, we identified 622 and 711 women (mean age: 69.2 and 69.7 years, respectively) who underwent either MRI or carotid ultrasound between 1992-2008 or 1993-2018, respectively. The highest quartile of gravidity (≥ 5 vs. 3) and delivery (≥ 4 vs. 2), and the highest and second highest (3 vs. 2) quartiles of delivery were associated with an increased risk of WMH and carotid artery plaque, respectively. Neither of age at menarche, menopause, and estrogen exposure period estimated by subtracting age at menarche from age at menopause was associated with atherosclerotic changes of brain and carotid arteries.

CONCLUSIONS

Higher gravidity and delivery are associated with subclinical atherosclerosis of the brain and carotid plaque.

Analysis of Risk Factors for White Matter Hyperintensity in Older Adults without Stroke

BACKGROUND

White matter hyperintensity (WMH) is prevalent in older adults aged 60 and above. A large proportion of people with WMH have not experienced stroke and little has been reported in the literature.

METHODS

The case data of patients aged ≥60 years without stroke in Wuhan Tongji Hospital from January 2015 to December 2019 were retrospectively analyzed. It was a cross-sectional study. Univariate analysis and logistic regression were used to analyze independent risk factors for WMH. The severity of WMH was assessed using the Fazekas scores. The participants with WMH were divided into periventricular white matter hyperintensity (PWMH) group and deep white matter hyperintensity (DWMH) group, then the risk factors of WMH severity were explored separately.

RESULTS

Eventually, 655 patients were included; among the patients, 574 (87.6%) were diagnosed with WMH. Binary logistic regression showed that age and hypertension were associated with the prevalence of WMH. Ordinal logistic regression showed that age, homocysteine, and proteinuria were associated with the severity of WMH. Age and proteinuria were associated with the severity of PWMH. Age and proteinuria were associated with the severity of DWMH.

CONCLUSIONS

The present study showed that in patients aged ≥60 years without stroke, age and hypertension were independent risk factors for the prevalence of WMH; while the increasing of age, homocysteine, and proteinuria were associated with greater WMH burden.

Development of a stroke risk score with MRI asymptomatic brain lesions attributes to evaluate prognostic vascular events

BACKGROUND

The use of a combination of stroke predictors, such as clinical factors and asymptomatic lesions on brain magnetic resonance imaging (MRI), may improve the accuracy of stroke risk prediction. Therefore, we attempted to develop a stroke risk score for healthy individuals.

METHODS

We investigated the presence of cerebral stroke in 2365 healthy individuals who underwent brain dock screening at the Health Science Center in Shimane. We examined the factors that contributed to stroke and attempted to determine the risk of stroke by comparing background factors and MRI findings.

RESULTS

The following items were found to be significant risk factors for stroke: age (≥60 years), hypertension, subclinical cerebral infarction, deep white matter lesion, and microbleeds. Each item was scored with 1 point, and the hazard ratios for the risk of developing stroke based on the group with 0 points were 17.2 (95% confidence interval [CI] 2.31-128) for 3 points, 18.1 (95% CI 2.03-162) for 4 points, and 102 (95% CI 12.6-836) for 5 points.

CONCLUSIONS

A precise stroke prediction score biomarker can be obtained by combining MRI findings and clinical factors.

Leukoaraiosis as a Predictor of Depression and Cognitive Impairment among Stroke Survivors: A Systematic Review

Stroke survivors are at increased risk of developing depression and cognitive decline. Thus, it is crucial for both clinicians and stroke survivors to be provided with timely and accurate prognostication of post-stroke depression (PSD) and post-stroke dementia (PSDem). Several biomarkers regarding stroke patients' propensity to develop PSD and PSDem have been implemented so far, leukoaraiosis (LA) being among them. The purpose of the present study was to review all available work published within the last decade dealing with pre-existing LA as a predictor of depression (PSD) and cognitive dysfunction (cognitive impairment or PSDem) in stroke patients. A literature search of two databases (MEDLINE and Scopus) was conducted to identify all relevant studies published between 1 January 2012 and 25 June 2022 that dealt with the clinical utility of preexisting LA as a prognostic indicator of PSD and PSDem/cognitive impairment. Only full-text articles published in the English language were included. Thirty-four articles were traced and are included in the present review. LA burden, serving as a surrogate marker of "brain frailty" among stroke patients, appears to be able to offer significant information about the possibility of developing PSD or cognitive dysfunction. Determining the extent of pre-existing white matter abnormalities can properly guide decision making in acute stroke settings, as a greater degree of such lesioning is usually coupled with neuropsychiatric aftermaths, such as PSD and PSDem.

Association of Incidentally Discovered Covert Cerebrovascular Disease Identified Using Natural Language Processing and Future Dementia

Background Covert cerebrovascular disease (CCD) has been shown to be associated with dementia in population-based studies with magnetic resonance imaging (MRI) screening, but dementia risk associated with incidentally discovered CCD is not known. Methods and Results Individuals aged ≥50 years enrolled in the Kaiser Permanente Southern California health system receiving head computed tomography (CT) or MRI for nonstroke indications from 2009 to 2019, without prior ischemic stroke/transient ischemic attack, dementia/Alzheimer disease, or visit reason/scan indication suggestive of cognitive decline or stroke were included. Natural language processing identified incidentally discovered covert brain infarction (id-CBI) and white matter disease (id-WMD) on the neuroimage report; white matter disease was characterized as mild, moderate, severe, or undetermined. We estimated risk of dementia associated with id-CBI and id-WMD. Among 241 050 qualified individuals, natural language processing identified 69 931 (29.0%) with id-WMD and 11 328 (4.7%) with id-CBI. Dementia incidence rates (per 1000 person-years) were 23.5 (95% CI, 22.9-24.0) for patients with id-WMD, 29.4 (95% CI, 27.9-31.0) with id-CBI, and 6.0 (95% CI, 5.8-6.2) without id-CCD. The association of id-WMD with future dementia was stronger in younger (aged <70 years) versus older (aged ≥70 years) patients and for CT- versus MRI-discovered lesions. For patients with versus without id-WMD on CT, the adjusted HR was 2.87 (95% CI, 2.58-3.19) for older and 1.87 (95% CI, 1.79-1.95) for younger patients. For patients with versus without id-WMD on MRI, the adjusted HR for dementia risk was 2.28 (95% CI, 1.99-2.62) for older and 1.48 (95% CI, 1.32-1.66) for younger patients. The adjusted HR for id-CBI was 2.02 (95% CI, 1.70-2.41) for older and 1.22 (95% CI, 1.15-1.30) for younger patients for either modality. Dementia risk was strongly correlated with id-WMD severity; adjusted HRs compared with patients who were negative for id-WMD by MRI ranged from 1.41 (95% CI, 1.25-1.60) for those with mild disease on MRI to 4.11 (95% CI, 3.58-4.72) for those with severe disease on CT. Conclusions Incidentally discovered CCD is common and associated with a high risk of dementia, representing an opportunity for prevention. The association is strengthened when discovered at younger age, by increasing id-WMD severity, and when id-WMD is detected by CT scan rather than MRI.

Association of covert brain infarcts and white matter hyperintensities with risk of hip fracture in older adults: the Cardiovascular Health Study

Covert brain infarcts and white matter hyperintensities (WMHs), incidental markers of brain microvascular disease commonly seen on brain MRIs in older adults, have been associated with falls and lower bone mineral density. We found covert infarcts and WMHs may also be associated with an increased risk of future hip fracture.

INTRODUCTION

To determine whether covert infarcts and white matter hyperintensities (WMHs) are associated with increased risk of incident hip fracture.

METHODS

A prospective cohort of 3373 community-dwelling adults aged ≥ 65 years enrolled in the Cardiovascular Health Study with a brain MRI (1992-1993) was analyzed. Covert infarcts were categorized by number of infarcts and largest infarct size. WMH burden was assessed by radiologists and graded qualitatively from 0 (no WMHs) to 9 (extensive).

RESULTS

Participants had 465 incident hip fractures during a mean follow-up of 12.8 years. The demographic-adjusted hazard of incident hip fracture was 32% higher among participants with ≥ 1 covert infarct compared to those without infarcts (hazard ratio (HR) 1.32; 95% CI, 1.08-1.62). The hazard of incident hip fracture was similar after further adjustment for medications and medical history (HR = 1.34; 95% CI, 1.08-1.65), but attenuated following additional adjustment for functional status, frailty, and falls (HR = 1.25; 95% CI, 0.99-1.57). Fully adjusted hazard of incident hip fracture per increase in infarct number was 1.10 (95% CI, 0.98-1.23); risk in individuals whose largest infarct was ≥ 20 mm versus 3 to < 20 mm was similar. Compared with WMH grades 0-1, the demographic-adjusted hazard of hip fracture was 1.34 (95% CI, 1.09-1.66) and 1.83 (95% CI, 1.37-2.46), respectively, for WMH grades 2-3 and 4-9. The hazard was similar following adjustment for medications and medical history (grades 2-3: HR = 1.32; 95% CI, 1.05-1.64; grades 4-9: HR = 1.69; 95% CI, 1.23-2.30), but attenuated following additional adjustment for functional status, frailty, and falls (grades 2-3: HR = 1.24; 95% CI, 0.98-1.56; grades 4-9: HR = 1.34; 95% CI, 0.95-1.90).

CONCLUSION

Older, community-dwelling adults with covert infarcts or WMHs may be at increased risk of hip fracture.

Dose-response association between plasma homocysteine and white matter lesions in patients with hypertension: a case-control study

White matter lesions (WMLs) are common MRI changes that are indicative of cerebral small vessel disease (CSVD). Elevated plasma homocysteine (Hcy) levels are related to an increased risk of vascular disease. We aimed to analyze the relationship between Hcy levels and WMLs in patients with hypertension. A total of 1961 patients with WMLs and 15,463 patients without WMLs were matched at a 1:1 ratio by age and sex. Hyperhomocysteinemia (HHcy) was defined as an abnormally high level (>15 µmol/l) of Hcy in a plasma sample. In total, 1888 (WML group) and 1888 (No-WMLs group) patients were enrolled, with 51.6% of the sample being male and a mean age of 63 years. Multivariate logistic regression analysis showed a significant association between a higher level of plasma Hcy and a higher prevalence of WMLs (OR 1.03 95% CI, 1.02-1.04) when the Hcy level was used as a continuous variable. Patients with Hcy levels of 15-20 µmol/l (OR 1.54, 95% CI 1.31-1.81) and >20 µmol/l (OR 1.51, 95% CI 1.26-1.82) also had a significantly higher risk of WMLs than patients with Hcy levels <15 µmol/l. Multivariable-adjusted spline regression models showed that the risk of WMLs started to increase only in patients with Hcy levels above 13.85 µmol/l (P < 0.001). In subgroup analyses of WMLs, there was no significant interaction between the Hcy group and subgroup heterogeneity for the prevalence of WMLs (P > 0.05). Our study found a dose-response association between plasma homocysteine levels, especially a Hcy level >13.85 µmol/l, and the prevalence of WMLs, implying that lowering Hcy levels might be a target for prevention.

Stratifying Future Stroke Risk with Incidentally Discovered White Matter Disease Severity and Covert Brain Infarct Site

BACKGROUND

Covert cerebrovascular disease (CCD) includes white matter disease (WMD) and covert brain infarction (CBI). Incidentally discovered CCD is associated with increased risk of subsequent symptomatic stroke. However, it is unknown whether the severity of WMD or the location of CBI predicts risk.

OBJECTIVES

The aim of this study was to examine the association of incidentally discovered WMD severity and CBI location with risk of subsequent symptomatic stroke.

METHOD

This retrospective cohort study includes patients aged ≥50 years old in the Kaiser Permanente Southern California health system who received neuroimaging for a nonstroke indication between 2009 and 2019. Incidental CBI and WMD were identified via natural language processing of the neuroimage report, and WMD severity was classified into grades.

RESULTS

A total of 261,960 patients received neuroimaging; 78,555 patients (30.0%) were identified to have incidental WMD and 12,857 patients (4.9%) to have incidental CBI. Increasing WMD severity is associated with an increased incidence rate of future stroke. However, the stroke incidence rate in CT-identified WMD is higher at each level of severity compared to rates in MRI-identified WMD. Patients with mild WMD via CT have a stroke incidence rate of 24.9 per 1,000 person-years, similar to that of patients with severe WMD via MRI. Among incidentally discovered CBI patients with a determined CBI location, 97.9% are subcortical rather than cortical infarcts. CBI confers a similar risk of future stroke, whether cortical or subcortical or whether MRI- or CT-detected.

CONCLUSIONS

Increasing severity of incidental WMD is associated with an increased risk of future symptomatic stroke, dependent on the imaging modality. Subcortical and cortical CBI conferred similar risks.

Impact of diabetes and ischemic stroke on the cerebrovasculature: A female perspective

There is a very complex interaction between the brain and the cerebral vasculature to meet the metabolic demands of the brain for proper function. Preservation of vascular networks and cerebrovascular function ultimately plays a key role in this intricate communication within the brain in health and disease. Experimental evidence showed that diabetes not only affects the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression, but also alters cerebrovascular function resulting in compromised myogenic reactivity and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain can rapidly occur. When an ischemic insult is superimposed on this pathology, not only is the neurovascular injury greater, but repair mechanisms fail, resulting in greater physical and cognitive deficits. While clinically it is known that women suffer disproportionately from diabetes as well as ischemic stroke and post-stroke cognitive impairment, the cerebrovascular architecture, patho/physiology, as well as cerebrovascular contributions to stroke recovery in female and diabetic animal models are inadequately studied and highlighted in this review.

Risk Factors for Silent Brain Infarcts and White Matter Disease in a Real-World Cohort Identified by Natural Language Processing

OBJECTIVE

To assess the frequency of silent brain infarcts (SBIs) and white matter disease (WMD) and associations with stroke risk factors (RFs) in a real-world population.

PATIENTS AND METHODS

This was an observational study of patients 50 years or older in the Kaiser Permanente Southern California health system from January 1, 2009, through June 30, 2019, with head computed tomography or magnetic resonance imaging for nonstroke indications and no history of stroke, transient ischemic attack, or dementia. A natural language processing (NLP) algorithm was applied to the electronic health record to identify individuals with reported SBIs or WMD. Multivariable Poisson regression estimated risk ratios of demographic characteristics, RFs, and scan modality on the presence of SBIs or WMD.

RESULTS

Among 262,875 individuals, the NLP identified 13,154 (5.0%) with SBIs and 78,330 (29.8%) with WMD. Stroke RFs were highly prevalent. Advanced age was strongly associated with increased risk of SBIs (adjusted relative risks [aRRs], 1.90, 3.23, and 4.72 for those aged in their 60s, 70s, and ≥80s compared with those in their 50s) and increased risk of WMD (aRRs, 1.79, 3.02, and 4.53 for those aged in their 60s, 70s, and ≥80s compared with those in their 50s). Magnetic resonance imaging was associated with a reduced risk of SBIs (aRR, 0.87; 95% CI, 0.83 to 0.91) and an increased risk of WMD (aRR, 2.86; 95% CI, 2.83 to 2.90). Stroke RFs had modest associations with increased risk of SBIs or WMD.

CONCLUSION

An NLP algorithm can identify a large cohort of patients with incidentally discovered SBIs and WMD. Advanced age is strongly associated with incidentally discovered SBIs and WMD.

Plasma aldosterone concentration is associated with white matter lesions in patients with primary aldosteronism

PURPOSE

Primary aldosteronism (PA) is the most frequent form of secondary hypertension. Hypertension is a risk factor for cognitive decline and dementia. White matter lesions (WMLs) are linked to vascular risk factors, which increase the risk of dementia. We aimed to analyze the association of PA-related parameters and WMLs in patients with PA.

METHODS

We conducted a retrospective analysis of all patients with PA in the Hypertension Center of the People's Hospital of Xinjiang Uygur Autonomous Region from January 1, 2011 to April 1, 2021. We analyzed the relationship between plasma aldosterone concentration (PAC), plasma renin activity (PRA), aldosterone-renin ratio (ARR), serum potassium, and WMLs.

RESULTS

We enrolled 138 patients with WMLs and matched these to controls without WMLs at a 1:4 ratio. Among the analytic sample (N = 711) with ages ranging from 30 to 64 years, 69% were male. In the logistic regression analysis, PAC, PRA and serum potassium were treated as continuous variables. The results showed that PAC (OR 1.04, 95% CI 1.01, 1.06, P = 0.008) was positively associated with the risk of WMLs, and serum potassium (OR 0.26, 95% CI 0.16, 0.44, P < 0.001) was inversely associated with the risk of WMLs. PRA (OR 0.86, 95% CI 0.68, 1.08, P = 0.384) was not associated with the risk of WMLs after adjusting for confounders. The results of restricted cubic splines showed the dose-response association between increasing PAC, ARR, decreasing serum potassium, and the risk of WMLs. We also divided PAC, ARR and serum potassium into two groups according to the result of restricted cubic splines. After adjusting for confounders, patients who were in Q2 (≥23.12 ng/dl) of PAC (OR 2.07, 95% CI 1.36, 3.15), Q2 (≥56.81 (ng/dl per ng/ml*h) of ARR (OR 1.82, 95% CI 1.22, 2.72) and Q2 (≤3.58 mmol/l) of serum potassium (OR 2.99, 95% CI 1.95, 4.50) had a significantly higher risk of WMLs than their counterparts. In stratified analyses, there was no evidence of subgroup heterogeneity regarding the change in the risk of WMLs (P > 0.05 for interaction for all).

CONCLUSION

Our results suggested that the PAC and serum potassium were related to the risk of WMLs in patients with PA. In particular, PAC ≥23.12 ng/dl significantly increased the risk of WMLs in patients with PA.

Diabetes and Ischemic Stroke: An Old and New Relationship an Overview of the Close Interaction between These Diseases

Diabetes mellitus is a comprehensive expression to identify a condition of chronic hyperglycemia whose causes derive from different metabolic disorders characterized by altered insulin secretion or faulty insulin effect on its targets or often both mechanisms. Diabetes and atherosclerosis are, from the point of view of cardio- and cerebrovascular risk, two complementary diseases. Beyond shared aspects such as inflammation and oxidative stress, there are multiple molecular mechanisms by which they feed off each other: chronic hyperglycemia and advanced glycosylation end-products (AGE) promote ‘accelerated atherosclerosis’ through the induction of endothelial damage and cellular dysfunction. These diseases impact the vascular system and, therefore, the risk of developing cardio- and cerebrovascular events is now evident, but the observation of this significant correlation has its roots in past decades. Cerebrovascular complications make diabetic patients 2–6 times more susceptible to a stroke event and this risk is magnified in younger individuals and in patients with hypertension and complications in other vascular beds. In addition, when patients with diabetes and hyperglycemia experience an acute ischemic stroke, they are more likely to die or be severely disabled and less likely to benefit from the one FDA-approved therapy, intravenous tissue plasminogen activator. Experimental stroke models have revealed that chronic hyperglycemia leads to deficits in cerebrovascular structure and function that may explain some of the clinical observations. Increased edema, neovascularization, and protease expression as well as altered vascular reactivity and tone may be involved and point to potential therapeutic targets. Further study is needed to fully understand this complex disease state and the breadth of its manifestation in the cerebrovasculature.

Night-Time Non-dipping Blood Pressure and Heart Rate: An Association With the Risk of Silent Small Vessel Disease in Patients Presenting With Acute Ischemic Stroke

Background and Purpose: Nocturnal non-dipping blood pressure and heart rate are associated with an increased risk of cardiovascular disease. The effects of such variance on cerebrovascular disease have not been well studied.

Methods: The 24-h ambulatory blood pressure (ABPM) and heart rate were monitored with B-pro in patients with acute stroke within the initial week of hospital admission. The risk factor profiles, clinical presentation, imaging, and short-term prognosis were compared in nocturnal dippers and non-dippers (more than 10% nocturnal decrease) of blood pressure and heart rate.

Results: We enrolled 234 patients in whom ABPM and MRI data were available. Heart rate data were available in 180 patients. Lacunar sub-cortical stroke was the most common acute lesion (58.9%), while hypertension (74%) and diabetes (41.5%) were the most common associated risk factors. ABPM revealed non-dipping in 69% of patients. On univariate analysis, Small Vessel Disease (SVD) was significantly more frequent in non-dippers vs. dippers (BP: 56.8 vs. 40.3% p = 0.02; heart rate: 57.9 vs. 40.7% p = 0.03). Silent strokes were also more frequent in non-dippers vs. dippers (BP: 40.7 vs. 26.4% p = 0.35; heart rate: 44.6 vs. 25.4% p = 0.01). Multivariate analysis revealed SVD to be significantly related to age, hypertension, blood pressure non-dipping, and severity of symptoms at index event.

Conclusions: The presence of nocturnal non-dipping of blood pressure and heart rate are associated with an increased risk of silent stroke and SVD. Increased use of ABPM may allow for improved diagnosis of non-dippers.

Risk Stratification Tool for Ischemic Stroke: A Risk Assessment Model Based on Traditional Risk Factors Combined With White Matter Lesions and Retinal Vascular Caliber

Objective: This study aims to establish a risk assessment model based on traditional risk factors combined with the Fazekas classification of white matter lesions and retinal vascular caliber for screening the patients at high risk of ischemic stroke.

Methods: This study included 296 patients (128 cases of ischemic stroke and 168 cases in the normal control group). The basic data of the patients were collected. Color fundus photography was performed after pupil dilation, and the retinal vascular caliber was measured using semiautomated vascular measurement software (IVAN Software, Sydney, Australia). The severity of white matter lesions (WML) on cranial nuclear magnetic fluid-attenuated inversion recovery images were assessed using the Fazekas scale. Moreover, logistic regression analysis was used to establish different risk assessment models for ischemic stroke. The effects of models were evaluated through the receiver operating characteristic (ROC) curve and the Delong test compared area under the curve.

Results: The sensitivity and specificity of models 1 (the traditional risk factor model), 2 (the retinal vascular caliber model), 3 (the WML model), and 4 (the combined the traditional risk factor, WML and central retinal artery equivalent (CRAE) model) were 71 and 55%, 48 and 71%, 49 and 67%, and 68 and 68.5% with areas under the curve of 0.658, 0.586, 0.601, and 0.708, respectively. The area under the receiver operating characteristic curve in models 1, 2, 3, and 4 showed statistically significant differences. Moreover, no statistical significance exists in the pairwise comparison of other models.

Conclusion: The risk assessment model of ischemic stroke combined with Fazekas grade of WML and CRAE is superior to the traditional risk factor and the single-index model. This model is helpful for risk stratification of high-risk stroke patients.

Cardiovascular damage phenotypes and all-cause and CVD mortality in older adults

PURPOSE

The association between CVD risk factors and mortality is well established, however, current tools for addressing subgroups have focused on the overall burden of disease. The identification of risky combinations of characteristics may lead to a better understanding of physiologic pathways that underlie morbidity and mortality in older adults.

METHODS

Participants included 5067 older adults from the Cardiovascular Health Study, followed for up to 6 years. Using latent class analysis (LCA), we created CV damage phenotypes based on probabilities of abnormal brain infarctions, major echocardiogram abnormalities, N-terminal probrain natriuretic peptide, troponin T, interleukin-6, c reactive-protein, galectin-3, cystatin C. We assigned class descriptions based on the probability of having an abnormality among risk factors, such that a healthy phenotype would have low probabilities in all risk factors. Participants were assigned to phenotypes based on the maximum probability of membership. We used Cox-proportional hazards regression to evaluate the association between the categorical CV damage phenotype and all-cause and CVD-mortality.

RESULTS

The analysis yielded 5 CV damage phenotypes consistent with the following descriptions: healthy (59%), cardio-renal (11%), cardiac (15%), multisystem morbidity (6%), and inflammatory (9%). All four phenotypes were statistically associated with a greater risk of all-cause mortality when compared with the healthy phenotype. The multisystem morbidity phenotype had the greatest risk of all-cause death (HR: 4.02; 95% CI: 3.44, 4.70), and CVD-mortality (HR: 4.90, 95% CI: 3.95, 6.06).

CONCLUSIONS

Five CV damage phenotypes emerged from CVD risk factor measures. CV damage across multiple systems confers a greater mortality risk compared to damage in any single domain.

Emerging role of white matter lesions in cerebrovascular disease

White matter lesions have been implicated in the setting of stroke, dementia, intracerebral haemorrhage, several other cerebrovascular conditions, migraine, various neuroimmunological diseases like multiple sclerosis, disorders of metabolism, mitochondrial diseases and others. While much is understood vis a vis neuroimmunological conditions, our knowledge of the pathophysiology of these lesions, and their role in, and implications to, management of cerebrovascular diseases or stroke, especially in the elderly, are limited. Several clinical assessment tools are available for delineating white matter lesions in clinical practice. However, their incorporation into clinical decision-making and specifically prognosis and management of patients is suboptimal for use in standards of care. This article sought to provide an overview of the current knowledge and recent advances on pathophysiology, as well as clinical and radiological assessment, of white matter lesions with a focus on its development, progression and clinical implications in cerebrovascular diseases. Key indications for clinical practice and recommendations on future areas of research are also discussed. Finally, a conceptual proposal on putative mechanisms underlying pathogenesis of white matter lesions in cerebrovascular disease has been presented. Understanding of pathophysiology of white matter lesions and how they mediate outcomes is important to develop therapeutic strategies.

White Matter Hyperintensity and Cardiovascular Disease Outcomes in the SPRINT MIND Trial

BACKGROUND

The Systolic Blood Pressure Intervention Trial (SPRINT) randomized patients to a goal systolic blood pressure (SBP) <120 mm Hg vs. <140 mm Hg. In a subset of participants, the SPRINT MIND ancillary study performed a baseline MRI and measured white matter hyperintensity volume (WMHv). In this secondary analysis, we evaluated the association between baseline WMHv and cardiovascular events during follow-up in the overall sample.

METHODS

The primary outcome was the same as SPRINT, a composite of stroke, myocardial infarction, acute coronary syndrome, decompensated congestive heart failure, or cardiovascular death. We fit Cox models to the primary outcome and report adjusted hazard ratios (HR) for log-transformed WMHv and quartiles of WMHv.

RESULTS

Among 717 participants, the median (IQR) baseline WMHv was 1.62 (0.66-3.98) mL. The primary outcome occurred in 51/719 (7.1%). The median WMHv was higher in patients with the primary outcome (3.40 mL versus 1.56 mL, p < 0.001). In adjusted models, WMHv as a log-transformed continuous variable was associated with the primary outcome (HR 1.44, 95% CI 1.15-1.80). The highest quartile of WMHv, compared to the lowest, was also independently associated with the primary outcome (HR 3.21, 95% CI 1.27-8.13).

CONCLUSIONS

We found that the baseline volume of WMH was associated with future CVD risk in SPRINT MIND. Prospective clinical trials with larger sample sizes than the current study are needed to determine whether intensive BP lowering can reduce the high cardiovascular risk in patients with WMH.

Increased internal cerebral vein diameter is associated with age

OBJECTIVE

A recent study described the relationship between cerebral venous diameter and white matter hyperintensity (WMH) volume. However, the adults were not further grouped; therefore, we aimed to compare across age groups and use susceptibility-weighted imaging (SWI) to explore whether there is also a relationship between a larger cerebral draining venous diameter and age, which could provide evidence of a temporal relationship.

METHODS

We retrospectively analysed data collected from 405 subjects (90 youths, 166 middle-aged participants, and 149 elderly subjects) and respectively used T2-weighted fluid-attenuated inversion recovery (FLAIR) and SWI to assess WMHs and venous diameter.

RESULTS

An increased internal cerebral vein (ICV) diameter was associated with age in different WMH groups (F = 3.453, 10.437, 11.746, and 21.723, respectively, all p < 0.001; multiple comparisons all p < 0.05), whereas the effect of the anterior septal vein (ASV) was opposite (F = 1.046, 1.210, 0.530, and 0.078, respectively, p > 0.05). There was a positive correlation between the ICV diameter and age with increasing WMH severity (R = 0.727, 0.709, 0.754, and 0.830, respectively, all p < 0.001). A statistically significant relationship between the thalamostriate vein (TSV) diameter and age was observed only in the moderate and severe WMH groups (F = 4.070 and 3.427, respectively, all p < 0.05; multiple comparisons all p < 0.05).

CONCLUSIONS

Our study demonstrates that increased TSV and ICV diameters are associated with age with increasing WMH severity, especially the ICV diameter using SWI.

Palm Fruit Bioactive Complex (PFBc), a Source of Polyphenols, Demonstrates Potential Benefits for Inflammaging and Related Cognitive Function

Cognitive function is a key aspect of healthy aging. Inflammation associated with normal aging, also called inflammaging is a primary risk factor for cognitive decline. A diet high in fruits and vegetable and lower in calories, particularly a Mediterranean Diet, may lower the risk of age-related cognitive decline due in part to the associated high intake of antioxidants and polyphenols. A phenolic, Palm Fruit Bioactive complex (PFBc) derived from the extraction process of palm oil from oil palm fruit (Elaeis guineensis), is reported to offset inflammation due to its high antioxidant, especially vitamin E, and polyphenol content. The benefit is thought to be achieved via the influence of antioxidants on gene expression. It is the purpose of this comprehensive review to discuss the etiology, including gene expression, of mild cognitive impairment (MCI) specific to dietary intake of antioxidants and polyphenols and to focus on the potential impact of nutritional interventions specifically PFBc has on MCI. Several in vitro, in vivo and animal studies support multiple benefits of PFBc especially for improving cognitive function via anti-inflammatory and antioxidant mechanisms. While more human studies are needed, those completed thus far support the benefit of consuming PFBc to enhance cognitive function via its anti-inflammatory antioxidant functions.

Lacunar Stroke Lesion Extent and Location and White Matter Hyperintensities Evolution 1 Year Post-lacunar Stroke

Lacunar strokes are a common type of ischemic stroke. They are associated with long-term disability, but the factors affecting the dynamic of the infarcted lesion and the brain imaging features associated with them, reflective of small vessel disease (SVD) severity, are still largely unknown. We investigated whether the distribution, volume and 1-year evolution of white matter hyperintensities (WMH), one of these SVD features, relate to the extent and location of these infarcts, accounting for vascular risk factors. We used imaging and clinical data from all patients [n = 118, mean age 64.9 (SD 11.75) years old] who presented to a regional hospital with a lacunar stroke syndrome within the years 2010 and 2013 and consented to participate in a study of stroke mechanisms. All patients had a brain MRI scan at presentation, and 88 had another scan 12 months after. Acute lesions (i.e., recent small subcortical infarcts, RSSI) were identified in 79 patients and lacunes in 77. Number of lacunes was associated with baseline WMH volume (B = 0.370, SE = 0.0939, P = 0.000174). RSSI volume was not associated with baseline WMH volume (B = 3.250, SE = 2.117, P = 0.129), but predicted WMH volume change (B = 2.944, SE = 0.913, P = 0.00184). RSSI location was associated with the spatial distribution of WMH and the pattern of 1-year WMH evolution. Patients with the RSSI in the centrum semiovale (n = 33) had significantly higher baseline volumes of WMH, recent and old infarcts, than patients with the RSSI located elsewhere [median 33.69, IQR (14.37 50.87) ml, 0.001 ≤ P ≤ 0.044]. But patients with the RSSI in the internal/external capsule/lentiform nucleus experienced higher increase of WMH volume after a year [n = 21, median (IQR) from 18 (11.70 31.54) ml to 27.41 (15.84 40.45) ml]. Voxel-wise analyses of WMH distribution in patients grouped per RSSI location revealed group differences increased in the presence of vascular risk factors, especially hypertension and recent or current smoking habit. In our sample of patients presenting to the clinic with lacunar strokes, lacunar strokes extent influenced WMH volume fate; and RSSI location and WMH spatial distribution and dynamics were intertwined, with differential patterns emerging in the presence of vascular risk factors. These results, if confirmed in wider samples, open potential avenues in stroke rehabilitation to be explored further.

Integrated analysis of microRNA and mRNA expression profiling identifies BAIAP3 as a novel target of dysregulated hsa-miR-1972 in age-related white matter lesions

White matter lesions known as leukoaraiosis (LA) are cerebral white matter hyperintensities observed in elderly individuals. Currently, no reliable molecular biomarkers are available for monitoring their progression over time. To identify biomarkers for the onset and progression of LA, we analyzed whole blood-based, microRNA expression profiles of leukoaraiosis, validated those exhibiting significant microRNA changes in clinical subjects by means of quantitative real-time polymerase chain reactions and determined the function of miRNA in cell lines by means of microRNA mimic transfection assays. A total of seven microRNAs were found to be significantly down-regulated in leukoaraiosis. Among the microRNAs, hsa-miR-1972 was downregulated during the early onset phase of leukoaraiosis, as confirmed in independent patients, and it was found to target leukoaraiosis-dependent BAIAP3, decreasing its expression in 293T cell lines. Functional enrichment analysis revealed that significantly dysregulated miRNAs-mRNAs changes associated with the onset of leukoaraiosis were involved in neurogenesis, neuronal development, and differentiation. Taken together, the study identified a set of candidate microRNA biomarkers that may usefully monitor the onset and progression of leukoaraiosis. Given the enrichment of leukoaraiosis-associated microRNAs and mRNAs in neuron part and membrane system, BAIAP3 could potentially represent a novel target of hsa-miR-1972 in leukoaraiosis through which microRNAs are involved in the pathogenesis of white matter lesions.

Positive Association Between Plasma Aldosterone Concentration and White Matter Lesions in Patients With Hypertension

BACKGROUND AND OBJECTIVE

White matter lesions (WMLs) are imaging changes in MRI of cerebral small vessel disease associated with vascular risk factors, increasing the risk of dementia, depression, and stroke. Aldosterone (ALD) or activation of mineralocorticoid receptor (MR) causes cerebrovascular injury in a mouse model. We aimed to analyze the relationship between ALD and WMLs in a population with hypertension.

METHODS

We conducted a retrospective review of all patients screened for causes of secondary hypertension. We enrolled 547 patients with WMLs and matched these to controls without WMLs at a 1:1 ratio. White matter lesion load was assessed by using a modified Scheltens' scale.

RESULTS

Among the analytic sample (N = 1,094) with ages ranging from 30 to 64 years, 62.2% were male. We divided plasma ALD concentration (PAC), plasma renin activity (PRA), and ALD-renin ratio (ARR) into the third tertile (Q3), second tertile (Q2), and first tertile (Q1). We also analyzed them simultaneously as continuous variables. Multivariate logistic regression analysis showed that participants in Q3 (>17.26 ng/dl) of PAC (OR 1.59, 95% CI 1.15, 2.19), Q3 (<0.80 ng/dl) of PRA (OR 2.50, 95% CI 1.81, 3.44), and Q3 (>18.59 ng/dl per ng/ml*h) of ARR (OR 2.90, 95% CI 2.10, 4.01) had a significantly higher risk of WMLs than those in Q1 (<12.48) of PAC, Q1 (>2.19) of PRA, and Q1 (<6.96) of ARR. In linear regression analysis, we separately analyzed the correlation between the modified Scheltens' scale score and log(PAC) (β = 2.36; 95% CI 1.30, 3.41; p < 0.001), log(PRA) (β = -1.76; 95% CI -2.09, -1.43; p < 0.001), and log(ARR) (β = 1.86; 95% CI 1.55, 2.17; p < 0.001), which were all significantly correlated with white matter lesion load, after adjusting for confounding factors. Simple mediation analyses showed that systolic blood pressure (SBP) or diastolic blood pressure (DBP) mediated -3.83% or -2.66% of the association between PAC and white matter lesion load, respectively. In stratified analyses, there was no evidence of subgroup heterogeneity concerning the change in the risk of WMLs (p > 0.05 for interaction for all).

CONCLUSION

Higher PAC, especially in PAC >17.26 ng/dl, increased the risk of WMLs. PAC was positively associated with white matter lesion load independent of SBP or DBP.

Overlapping Protein Accumulation Profiles of CADASIL and CAA: Is There a Common Mechanism Driving Cerebral Small-Vessel Disease?

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and cerebral amyloid angiopathy (CAA) are two distinct vascular angiopathies that share several similarities in clinical presentation and vascular pathology. Given the clinical and pathologic overlap, the molecular overlap between CADASIL and CAA was explored. CADASIL and CAA protein profiles from recently published proteomics-based and immuno-based studies were compared to investigate the potential for shared disease mechanisms. A comparison of affected proteins in each disease highlighted 19 proteins that are regulated in both CADASIL and CAA. Functional analysis of the shared proteins predicts significant interaction between them and suggests that most enriched proteins play roles in extracellular matrix structure and remodeling. Proposed models to explain the observed enrichment of extracellular matrix proteins include both increased protein secretion and decreased protein turnover by sequestration of chaperones and proteases or formation of stable protein complexes. Single-cell RNA sequencing of vascular cells in mice suggested that the vast majority of the genes accounting for the overlapped proteins between CADASIL and CAA are expressed by fibroblasts. Thus, our current understanding of the molecular profiles of CADASIL and CAA appears to support potential for common mechanisms underlying the two disorders.

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.

Night-time systolic blood pressure and subclinical cerebrovascular disease: the Cardiovascular Abnormalities and Brain Lesions (CABL) study

AIMS

Although ambulatory blood pressure (BP) is a better predictor of cardiovascular outcomes than office BP, its association with subclinical cerebrovascular disease is not clarified. We investigated the associations of office and ambulatory BP values with subclinical cerebrovascular disease in a population based, predominantly elderly cohort without prior stroke.

METHODS AND RESULTS

Eight hundred and twenty-eight participants underwent 24-h ambulatory BP monitoring (ABPM), 2D echocardiography and brain magnetic resonance imaging in the Cardiac Abnormalities and Brain Lesion (CABL) study. Daytime, night-time, and 24-h BPs, nocturnal dipping pattern, morning surge (MS), and 24-h variability were assessed. Subclinical cerebrovascular disease was defined as silent brain infarcts (SBIs) and white matter hyperintensity volume (WMHV). The association of BP measures with the presence of SBI and upper quartile of log-WMHV (log-WMHV4) was analysed. SBIs were detected in 111 patients (13.4%). Mean log-WMHV was -0.99 ± 0.94. In multivariable analysis, only night-time systolic BP (SBP) was significantly associated with SBI [odds ratio (OR) 1.15 per 10 mmHg, P = 0.042], independent of cardiovascular risk factors, and pertinent echocardiographic parameters. Although daytime, night-time, 24-h BPs, and non-dipping pattern were all significantly associated with log-WMHV4 (all P < 0.05), night-time SBP showed the strongest association (OR 1.21 per 10 mmHg, P = 0.003) and was the sole independent predictor when tested against the other BP parameters. Office BP measures, MS, and BP variability were not associated with subclinical cerebrovascular disease in adjusted analyses.

CONCLUSION

Elevated night-time SBP is strongly associated with subclinical cerebrovascular disease. Night-time SBP by ABPM allows to identify individuals at higher risk of hypertensive brain injury.

Attention convolutional neural network for accurate segmentation and quantification of lesions in ischemic stroke disease

Ischemic stroke lesion and white matter hyperintensity (WMH) lesion appear as regions of abnormally signal intensity on magnetic resonance image (MRI) sequences. Ischemic stroke is a frequent cause of death and disability, while WMH is a risk factor for stroke. Accurate segmentation and quantification of ischemic stroke and WMH lesions are important for diagnosis and prognosis. However, radiologists have a difficult time distinguishing these two types of similar lesions. A novel deep residual attention convolutional neural network (DRANet) is proposed to accurately and simultaneously segment and quantify ischemic stroke and WMH lesions in the MRI images. DRANet inherits the advantages of the U-net design and applies a novel attention module that extracts high-quality features from the input images. Moreover, the Dice loss function is used to train DRANet to address data imbalance in the training data set. DRANet is trained and evaluated on 742 2D MRI images which are produced from the sub-acute ischemic stroke lesion segmentation (SISS) challenge. Empirical tests demonstrate that DRANet outperforms several other state-of-the-art segmentation methods. It accurately segments and quantifies both ischemic stroke lesion and WMH. Ablation experiments reveal that attention modules improve the predictive performance of DRANet.

Total small vessel disease score and functional outcomes following acute intracerebral hemorrhage

BACKGROUND

Individual cerebral small vessel disease (SVD) markers are independent predictors for poor prognosis following intracerebral hemorrhage (ICH), however, the impact of the cumulative SVD burden on outcomes remains unclear. We aimed to investigate the association between the global SVD burden and functional outcomes following ICH.

METHODS

We retrospectively evaluated a consecutive cohort of patients with ICH who underwent brain magnetic resonance imaging and magnetic resonance angiography, from a prospective registry. We identified the presence and severity of the SVD markers (cerebral microbleeds, lacunar infarctions, periventricular hyperintensities, and deep white matter hyperintensities) and summed them to obtain the modified total SVD score (0-4). Poor functional outcomes were defined as a modified Rankin Scale score at discharge ≥ 3. A multivariate logistic regression model was used to assess the association between patient outcomes and the SVD score.

RESULTS

A total of 144 patients were included (65.0 ± 12.2 years, 67.4% male). The modified total SVD score was potentially associated with poor functional outcomes (odds ratio [OR] 1.72, 95% confidence interval [CI] 0.97-3.03) after adjustment for age, sex, history of stroke, chronic kidney disease, prior use of antithrombotic agents, the National Institutes of Health Stroke Scale score on admission, the non-lobar location of ICH, and hematoma volume on admission. Moreover, among older patients (≥ 65 years), the SVD score was associated with poor outcomes (OR 3.11, 95% CI 1.01-9.55). Among those with supratentorial ICH, the score remained significant (OR 2.06, 95% CI 1.11-3.83).

CONCLUSIONS

The modified total SVD score may have predictive value for poor functional outcomes following ICH.

Morphology of perivascular spaces and enclosed blood vessels in young to middle-aged healthy adults at 7T: Dependences on age, brain region, and breathing gas

Perivascular spaces (PVSs) are fluid-filled spaces surrounding penetrating blood vessels in the brain and are an integral pathway of the glymphatic system. A PVS and the enclosed blood vessel are commonly visualized as a single vessel-like complex (denoted as PVSV) in high-resolution MRI images. Quantitative characterization of the PVSV morphology in MRI images in healthy subjects may serve as a reference for detecting disease related PVS and/or blood vessel alterations in patients with brain diseases.

To this end, we evaluated the age dependences, spatial heterogeneities, and dynamic properties of PVSV morphological features in 45 healthy subjects (21–55 years old), using an ultra-high-resolution three-dimensional transverse relaxation time weighted MRI sequence (0.41 × 0.41 × 0.4 mm³) at 7T. Quantitative PVSV parameters, including apparent diameter, count, volume fraction (VF), and relative contrast to noise ratio (rCNR) were calculated in the white matter and subcortical structures. Dynamic changes were induced by carbogen breathing which are known to induce vasodilation and increase the blood oxygenation level in the brain.

PVSV count and VF significantly increased with age in basal ganglia (BG), so did rCNR in BG, midbrain, and white matter (WM). Apparent PVSV diameter also showed a positive association with age in the three brain regions, although it did not reach statistical significance. The PVSV VF and count showed large inter-subject variations, with coefficients of variation ranging from 0.17 to 0.74 after regressing out age and gender effects. Both apparent diameter and VF exhibited significant spatial heterogeneity, which cannot be explained solely by radio-frequency field inhomogeneities. Carbogen breathing significantly increased VF in BG and WM, and rCNR in thalamus, BG, and WM compared to air breathing.

Our results are consistent with gradual dilation of PVSs with age in healthy adults. The PVSV morphology exhibited spatial heterogeneity and large inter-subject variations and changed during carbogen breathing compared to air breathing.

Hemodynamic Significance of Middle Cerebral Artery Stenosis Associated With the Severity of Ipsilateral White Matter Changes

Background: Previous studies conflicted in the association between intracranial atherosclerotic stenosis (ICAS) and the severity of white matter changes (WMC).

Aims: We aimed to investigate the relationships between the severity of luminal stenosis and the hemodynamic significance of middle cerebral artery (MCA) stenosis, and the severity of ipsilateral WMC.

Methods: In this cross-sectional study, patients with a recent ischemic stroke or transient ischemic attack and a 50–99% MCA-M1 stenosis in the Chinese Intracranial Atherosclerosis study cohort were analyzed. The post- to pre-stenotic signal intensity ratio (SIR) was obtained in time-of-flight MR angiography (MRA) to represent the hemodynamic significance of MCA-M1 stenosis, with a lower SIR indicating a hemodynamically more severe lesion. The severity of ipsilesional WMC was assessed by an age-related WMC (ARWMC) scale in T2-weighted fluid attenuated inversion recovery MR imaging. The relationships between the degree of MCA-M1 stenosis, SIR, and ipsilesional ARWMC scale were analyzed. The MCA-M1 lesion with a higher percentage of stenosis was chosen for analyses in patients with bilateral MCA-M1 stenoses.

Results: Among 180 subjects (mean age, 64 years), a lower SIR of MCA-M1 stenosis (Spearman correlation coefficient, −0.543; p < 0.001), but not the degree of stenosis (p = 0.93), was significantly linearly correlated with a higher ipsilateral ARWMC. Multivariate ordinal logistic regression identified older age (OR = 1.037; 95% CI, 1.008–1.066; p = 0.011) and lower SIR (OR = 0.010; 95% CI, 0.002–0.058; p < 0.001) as independent predictors for more severe ipsilateral WMC.

Conclusion: Patients with hemodynamically more severe ICAS are more likely to have more severe ipsilateral WMC. Longitudinal studies with sequential imaging exams may further reveal the impact of hemodynamic significance of ICAS on the development and progression of WMC.

Association between white matter hyperintensities and stroke in a West African patient population: Evidence from the Stroke Investigative Research and Educational Network study

BACKGROUND

This study is part of the Stroke Investigative Research and Educational Network (SIREN), the largest study of stroke patients in Africa to date, with computed tomography (CT) or magnetic resonance (MR) imaging data for each patient to confirm stroke. Prior imaging studies performed using high-field MR (≥1.5T) have shown that white matter hyperintensities (WMH), signs of microangiopathy in the subcortical brain, are correlated with many stroke risk factors as well as poor stroke outcomes. The aim of this study was the evaluation of MR images (0.3T-1.5T) from the SIREN study to determine associations between WMH volumes in West African patients and both stroke outcomes and stroke risk factors identified in the SIREN study.

MATERIALS AND METHODS

Brain MR images of 130 Western African stroke patients (age ​= ​57.87 ​± ​14.22) were processed through Lesion Segmentation Toolbox of the Statistical Parametric Mapping software to extract all areas of hyperintensity in the brain. WMH was separated from stroke lesion hyperintensity and WMH volume was computed and summed. A stepwise linear regression and multivariate analysis was performed between patients' WMH volume and sociodemographic and clinical indices.

RESULTS

Multivariate analysis showed that high WMH volume was statistically significantly positively correlated with age (β ​= ​0.44, p ​= ​0.001), waist/hip ratio (β ​= ​0.22, p ​= ​0.03), and platelet count (β ​= ​0.19, p ​= ​0.04) after controlling for head size in a Western African stroke population.

CONCLUSION

Associations between WMH and age and waist/hip ratio previously identified in Western countries were demonstrated for the first time in a resource-limited, homogeneous black African community using low-field MR scanners.

Radiation-induced accelerated aging of the brain vasculature in young adult survivors of childhood brain tumors

Background

Cranial radiotherapy may damage the cerebral vasculature. The aim of this study was to understand the prevalence and risk factors of cerebrovascular disease (CVD) and white matter hyperintensities (WMHs) in childhood brain tumors (CBT) survivors treated with radiotherapy.

Methods

Seventy CBT survivors who received radiotherapy were enrolled in a cross-sectional study at a median 20 years after radiotherapy cessation. The prevalence of and risk factors for CVD were investigated using MRI, MRA, and laboratory testing. Tumors, their treatment, and stroke-related data were retrieved from patients’ files.

Results

Forty-four individuals (63%) had CVD at a median age of 27 years (range, 16-43 years). The prevalence rates at 20 years for CVD, small-vessel disease, and large-vessel disease were 52%, 38%, and 16%, respectively. Ischemic infarcts were diagnosed in 6 survivors, and cerebral hemorrhage in 2. Lacunar infarcts were present in 7, periventricular or deep WMHs in 34 (49%), and mineralizing microangiopathy in 21 (30%) survivors. Multiple pathologies were detected in 44% of the participants, and most lesions were located in a high-dose radiation area. Higher blood pressure was associated with CVD and a presence of WMHs. Higher cholesterol levels increased the risk of ischemic infarcts and WMHs, and lower levels of high-density lipoprotein and higher waist circumference increased the risk of lacunar infarcts.

Conclusions

Treating CBTs with radiotherapy increases the risk of early CVD and WMHs in young adult survivors. These results suggest an urgent need for investigating CVD prevention in CBT patients.

Damage to the shortest structural paths between brain regions is associated with disruptions of resting-state functional connectivity after stroke

Focal brain lesions disrupt resting-state functional connectivity, but the underlying structural mechanisms are unclear. Here, we examined the direct and indirect effects of structural disconnections on resting-state functional connectivity in a large sample of sub-acute stroke patients with heterogeneous brain lesions. We estimated the impact of each patient's lesion on the structural connectome by embedding the lesion in a diffusion MRI streamline tractography atlas constructed using data from healthy individuals. We defined direct disconnections as the loss of direct structural connections between two regions, and indirect disconnections as increases in the shortest structural path length between two regions that lack direct structural connections. We then tested the hypothesis that functional connectivity disruptions would be more severe for disconnected regions than for regions with spared connections. On average, nearly 20% of all region pairs were estimated to be either directly or indirectly disconnected by the lesions in our sample, and extensive disconnections were associated primarily with damage to deep white matter locations. Importantly, both directly and indirectly disconnected region pairs showed more severe functional connectivity disruptions than region pairs with spared direct and indirect connections, respectively, although functional connectivity disruptions tended to be most severe between region pairs that sustained direct structural disconnections. Together, these results emphasize the widespread impacts of focal brain lesions on the structural connectome and show that these impacts are reflected by disruptions of the functional connectome. Further, they indicate that in addition to direct structural disconnections, lesion-induced increases in the structural shortest path lengths between indirectly structurally connected region pairs provide information about the remote functional disruptions caused by focal brain lesions.

Association of CD14 with incident dementia and markers of brain aging and injury

OBJECTIVE

To test the hypothesis that the inflammatory marker plasma soluble CD14 (sCD14) associates with incident dementia and related endophenotypes in 2 community-based cohorts.

METHODS

Our samples included the prospective community-based Framingham Heart Study (FHS) and Cardiovascular Health Study (CHS) cohorts. Plasma sCD14 was measured at baseline and related to the incidence of dementia, domains of cognitive function, and MRI-defined brain volumes. Follow-up for dementia occurred over a mean of 10 years (SD 4) in the FHS and a mean of 6 years (SD 3) in the CHS.

RESULTS

We studied 1,588 participants from the FHS (mean age 69 ± 6 years, 47% male, 131 incident events) and 3,129 participants from the CHS (mean age 72 ± 5 years, 41% male, 724 incident events) for the risk of incident dementia. Meta-analysis across the 2 cohorts showed that each SD unit increase in sCD14 was associated with a 12% increase in the risk of incident dementia (95% confidence interval 1.03-1.23; p = 0.01) following adjustments for age, sex, APOE ε4 status, and vascular risk factors. Higher levels of sCD14 were associated with various cognitive and MRI markers of accelerated brain aging in both cohorts and with a greater progression of brain atrophy and a decline in executive function in the FHS.

CONCLUSION

sCD14 is an inflammatory marker related to brain atrophy, cognitive decline, and incident dementia.

Differential Influence of Location-Specific White-Matter Hyperintensities on Attention Subdomains Measured Using the Attention Network Test

BACKGROUND Elderly people with white-matter hyperintensities (WMHs) typically show cognitive impairment. Attention, consisting of 3 independent component processes (alerting, orienting, and executive control), is crucial for cognitive functioning. Little is known about how WMHs interfere with these attention subdomains. In the present study, we sought to describe characteristics of attention deficits in patients with age-related WMHs and to assess whether the severity and location of lesions differentially affect specific attention subdomains using the attention network test (ANT), which is a computer-based paradigm tailored to accurately provide behavioral measures of the aforementioned subdomains. MATERIAL AND METHODS A total of 39 WMH patients and 39 age-, sex-, and education-matched controls underwent comprehensive neuropsychological and ANT evaluation. Brain magnetic resonance imaging (MRI) was performed to visualize severity of total and location-specific WMH lesions. Multiple linear regression analyses adjusted for possible confounders were performed. RESULTS Compared with controls, WMH patients showed pronounced deficits in orienting and executive control efficiencies (P<0.050), but not alerting efficiency (P=0.642). As total WMH severity increased, efficiencies in the impaired subdomains significantly declined (P<0.050). In terms of lesion location, fronto-parietal type of periventricular WMH (PWMH) and deep WMH (DWMH) in the parietal lobe affected orienting efficiency, while all PWMH types and DWMH in the frontal, parietal, and temporal lobes affected executive control efficiency (P<0.050). Additional adjustment for other MRI lesions significantly changed the impact on orienting, but not on executive control efficiency. CONCLUSIONS Our results reveal specific attention deficits in patients with age-related WMH and may help clarify how the location of lesions influences their effects on attention subdomains.

Dietary Inflammatory Index and Leukoaraiosis in Patients with Ischemic Stroke

OBJECTIVES

Diet may change the chronic levels of systemic inflammation, which in turn influence the development of leukoaraiosis (LA). This study aimed to examine the association between dietary inflammatory index (DII) and LA in patients with ischemic stroke.

METHODS

Patients with first-ever ischemic stroke were enrolled from two centers. A semi-quantitative food frequency questionnaire (FFQ) was used to evaluate diet contents. The DII score of each patient was calculated based on the reported diet contents. Presence and degree of LA were evaluated with a magnetic resonance imaging (MRI) scan. LA was graded according to Fazekas scale.

RESULTS

Of the 497 enrolled patients, 337 (67.8%) were detected with LA. Patients with LA had a higher DII score (0.23 vs -0.88, P < 0.001). Logistic regression analysis detected that patients with highest quartile of DII score had an OR of 3.61 (95% CI: 2.05-6.36, P < 0.001) for LA compared with those with lowest quartile of DII. After adjusting for major confounders, the highest DII quartile remained as an independent predictor for LA (OR = 2.66, 95% CI: 1.41-5.00, P = 0.008).

CONCLUSIONS

A pro-inflammatory diet pattern, as indicated by higher DII values, appears to be associated with a higher risk of LA. This result suggested that dietary-mediated inflammation may involved in the pathogenesis of LA, which warrant further study.

Clinical Significance of Magnetic Resonance Imaging Markers of Vascular Brain Injury: A Systematic Review and Meta-analysis

Importance

Covert vascular brain injury (VBI) is highly prevalent in community-dwelling older persons, but its clinical and therapeutic implications are debated.

Objective

To better understand the clinical significance of VBI to optimize prevention strategies for the most common age-related neurological diseases, stroke and dementia.

Data Source

We searched for articles in PubMed between 1966 and December 22, 2017, studying the association of 4 magnetic resonance imaging (MRI) markers of covert VBI (white matter hyperintensities [WMHs] of presumed vascular origin, MRI-defined covert brain infarcts [BIs], cerebral microbleeds [CMBs], and perivascular spaces [PVSs]) with incident stroke, dementia, or death.

Study Selection

Data were taken from prospective, longitudinal cohort studies including 50 or more adults.

Data Extraction and Synthesis

We performed inverse variance-weighted meta-analyses with random effects and z score-based meta-analyses for WMH burden. The significance threshold was P < .003 (17 independent tests). We complied with the Meta-analyses of Observational Studies in Epidemiology guidelines.

Main Outcomes and Measures

Stroke (hemorrhagic and ischemic), dementia (all and Alzheimer disease), and death.

Results

Of 2846 articles identified, 94 studies were eligible, with up to 14 529 participants for WMH, 16 012 participants for BI, 15 693 participants for CMB, and 4587 participants for PVS. Extensive WMH burden was associated with higher risk of incident stroke (hazard ratio [HR], 2.45; 95% CI, 1.93-3.12; P < .001), ischemic stroke (HR, 2.39; 95% CI, 1.65-3.47; P < .001), intracerebral hemorrhage (HR, 3.17; 95% CI, 1.54-6.52; P = .002), dementia (HR, 1.84; 95% CI, 1.40-2.43; P < .001), Alzheimer disease (HR, 1.50; 95% CI, 1.22-1.84; P < .001), and death (HR, 2.00; 95% CI, 1.69-2.36; P < .001). Presence of MRI-defined BIs was associated with higher risk of incident stroke (HR, 2.38; 95% CI, 1.87-3.04; P < .001), ischemic stroke (HR, 2.18; 95% CI, 1.67-2.85; P < .001), intracerebral hemorrhage (HR, 3.81; 95% CI, 1.75-8.27; P < .001), and death (HR, 1.64; 95% CI, 1.40-1.91; P < .001). Presence of CMBs was associated with increased risk of stroke (HR, 1.98; 95% CI, 1.55-2.53; P < .001), ischemic stroke (HR, 1.92; 95% CI, 1.40-2.63; P < .001), intracerebral hemorrhage (HR, 3.82; 95% CI, 2.15-6.80; P < .001), and death (HR, 1.53; 95% CI, 1.31-1.80; P < .001). Data on PVS were limited and insufficient to conduct meta-analyses but suggested an association of high PVS burden with increased risk of stroke, dementia, and death; this requires confirmation.

Conclusions and Relevance

We report evidence that MRI markers of VBI have major clinical significance. This research prompts careful evaluation of the benefit-risk ratio for available prevention strategies in individuals with covert VBI.

Increased Diameters of the Internal Cerebral Veins and the Basal Veins of Rosenthal Are Associated with White Matter Hyperintensity Volume

BACKGROUND AND PURPOSE

White matter hyperintensities on T2-weighted MR imaging are typical in older adults and have been linked to several poor health outcomes, including cognitive impairment and Alzheimer disease. The presence and severity of white matter hyperintensities have traditionally been attributed to occlusive arteriopathy, but recent evidence also implicates deep medullary venule collagenosis and associated vasogenic edema. Historically, postmortem analyses have been the sole way to analyze cerebral veins, but SWI can be now used to examine cortical veins in vivo. The aim of the current study was to determine whether there is an association between the diameters of the large draining cerebral veins/sinuses and white matter hyperintensity volume.

MATERIALS AND METHODS

T2-weighted FLAIR and SWI were performed in 682 older adults without dementia (mean age, 73.9 ± 5.9 years; 59.1% women). Total and regional white matter hyperintensity volume was derived. We measured the diameters of 5 regions of the cerebral venous draining system: internal cerebral veins, basal veins of Rosenthal, superior sagittal sinus, vein of Galen, and straight sinus terminus.

RESULTS

Increased diameter of the internal cerebral veins was associated with greater total white matter hyperintensity volume (β = 0.09, P = .02) and regionally in the parietal (β = 0.10, P = .006), frontal (β = 0.09, P = .02), and temporal (β = 0.09, P = .02) lobes. Increased diameter of the basal veins of Rosenthal was associated with greater total (β = 0.10, P = .01), frontal (β = 0.11, P = .003), and temporal (β = 0.09, P = .02) white matter hyperintensity volume.

CONCLUSIONS

Our results suggest that the caliber of the internal cerebral veins and of the basal veins of Rosenthal relates to regional white matter disease.

Association between carotid 18F-NaF and 18F-FDG uptake on PET/CT with ischemic vascular brain disease on MRI in patients with carotid artery disease

OBJECTIVE

Atherosclerosis is a dynamic and complex process characterized by the formation and progression of plaque mediated by various pathophysiologic steps including inflammation and calcification. The present study aimed to evaluate the association between carotid ¹⁸F-sodium fluoride (NaF) and ¹⁸F-fluorodeoxyglucose (FDG) uptake with the severity of ischemic vascular brain disease on MRI in patients with carotid artery disease.

METHODS

A total of 28 patients who were scheduled to undergo clinically indicated carotid endarterectomy or stenting for carotid artery disease were examined with ¹⁸F-NaF and ¹⁸F-FDG PET/CT and brain MRI. The PET/CT images were evaluated by qualitative and semiquantitative analyses. The maximum standardized uptake value (SUV) for the plaque and the average of mean SUV within the lumen of both internal jugular veins was calculated, and the target-to-blood pool ratio (TBR) was determined. The ischemic vascular brain disease on MRI was graded separately in the bilateral hemisphere as 0, 1, 2, and 3, with 0 being absent and 3 being the most severe.

RESULTS

In two patients, only a unilateral carotid artery was analyzed because of previous indwelling stent. ¹⁸F-NaF focal uptake was observed in 50 carotid arteries. ¹⁸F-FDG focal uptake was observed in 47 carotid arteries. The mean (± SD) ¹⁸F-NaF TBR (2.93 ± 0.89) was significantly higher than the mean (± SD) ¹⁸F-FDG TBR (2.41 ± 0.84) (p < 0.001). The mean (± SD) values of ¹⁸F-NaF TBR were 2.63 ± 0.76 in grade 1, 2.90 ± 0.91 in grade 2, and 3.81 ± 0.60 in grade 3. Significant differences in ¹⁸F-NaF TBR were observed between grades 1 and 3 (p < 0.001) and grades 2 and 3 (p = 0.02). The mean (± SD) values of ¹⁸F-FDG TBR were 2.35 ± 0.77 in grade 1, 2.23 ± 0.48 in grade 2, and 2.87 ± 1.32 in grade 3. No significant differences in ¹⁸F-FDG TBR were noted between any of the ischemic vascular brain disease grades.

CONCLUSIONS

These preliminary results suggest that carotid ¹⁸F-NaF uptake in patients with carotid artery disease may be associated with the severity of the ischemic vascular brain disease observed on MRI.

Exome Chip Analysis Identifies Low-Frequency and Rare Variants in MRPL38 for White Matter Hyperintensities on Brain Magnetic Resonance Imaging

Background and Purpose- White matter hyperintensities (WMH) on brain magnetic resonance imaging are typical signs of cerebral small vessel disease and may indicate various preclinical, age-related neurological disorders, such as stroke. Though WMH are highly heritable, known common variants explain a small proportion of the WMH variance. The contribution of low-frequency/rare coding variants to WMH burden has not been explored. Methods- In the discovery sample we recruited 20 719 stroke/dementia-free adults from 13 population-based cohort studies within the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, among which 17 790 were of European ancestry and 2929 of African ancestry. We genotyped these participants at ≈250 000 mostly exonic variants with Illumina HumanExome BeadChip arrays. We performed ethnicity-specific linear regression on rank-normalized WMH in each study separately, which were then combined in meta-analyses to test for association with single variants and genes aggregating the effects of putatively functional low-frequency/rare variants. We then sought replication of the top findings in 1192 adults (European ancestry) with whole exome/genome sequencing data from 2 independent studies. Results- At 17q25, we confirmed the association of multiple common variants in TRIM65, FBF1, and ACOX1 ( P<6×10^-7). We also identified a novel association with 2 low-frequency nonsynonymous variants in MRPL38 (lead, rs34136221; P_EA=4.5×10^-8) partially independent of known common signal ( P_{EA(conditional)}=1.4×10^-3). We further identified a locus at 2q33 containing common variants in NBEAL1, CARF, and WDR12 (lead, rs2351524; P_all=1.9×10^-10). Although our novel findings were not replicated because of limited power and possible differences in study design, meta-analysis of the discovery and replication samples yielded stronger association for the 2 low-frequency MRPL38 variants ( P_rs34136221=2.8×10^-8). Conclusions- Both common and low-frequency/rare functional variants influence WMH. Larger replication and experimental follow-up are essential to confirm our findings and uncover the biological causal mechanisms of age-related WMH.

Subclinical Cerebrovascular Disease: Epidemiology and Treatment

PURPOSE OF REVIEW

Subclinical cerebrovascular disease (sCVD) is highly prevalent in older adults. The main neuroimaging findings of sCVD include white matter hyperintensities and silent brain infarcts on T2-weighted MRI and cerebral microbleeds on gradient echo or susceptibility-weighted MRI. In this paper, we will review the epidemiology of sCVD, the current evidence for best medical management, and future directions for sCVD research.

RECENT FINDINGS

Numerous epidemiologic studies show that sCVD, in particular WMH, is an important risk factor for the development of dementia, stroke, worse outcomes after stroke, gait instability, late-life depression, and death. Effective treatment of sCVD could have major consequences for the brain health of a substantial portion of older Americans. Despite the link between sCVD and many vascular risk factors, such as hypertension or hyperlipidemia, the optimal medical treatment of sCVD remains uncertain. Given the clinical equipoise about the risk versus benefit of aggressive medical management for sCVD, clinical trials to examine pragmatic, evidence-based approaches to management of sCVD are needed. Such a trial could provide much needed guidance on how to manage a common clinical scenario facing internists and neurologists in practice.

Neuropsychological impact of white matter hyperintensities in older adults without dementia

The purpose of this study was to determine (a) if simple clinical judgements of white matter hyperintensities (WMH) on imaging are associated with measurable cognitive impacts in otherwise cognitively normal older adults, (b) if neuropsychological measures can predict those with WMH, and (c) the frequency of low cognitive scores in those with WMH on a battery of measures. Forty-four individuals judged free of other cognitive disorders despite moderate to extensive WMH were compared with 50 individuals matched on age (mean of 83), education (college educated), and gender (predominantly female). Data was obtained from the National Alzheimer's Coordinating Center database. The group with at least moderate WMH had lower scores on the Trail Making Test A, verbal fluency, and digit span. A component score derived from these measures was a significant predictor of the presence of WMH, though only correctly classified 68% of participants. Even in individuals free from other suspected conditions, clinically judged moderate to extensive WMH was associated with cognitive weaknesses for processing speed, working memory, and executive functioning. This shows that a relatively simple judgment of WMH burden is meaningfully associated with worse cognition. Implications and future directions for are discussed.

Carotid Artery Stiffness Accurately Predicts White Matter Hyperintensity Volume 20 Years Later: A Secondary Analysis of the Atherosclerosis Risk in the Community Study

BACKGROUND AND PURPOSE

Arterial stiffness is a biomarker of cerebrovascular disease and dementia risk. Studies have shown an association between carotid artery stiffness and increased white matter hyperintensity volume and, as a result, reduced total brain volume on MR imaging, but none have had prolonged follow-up to fully evaluate the slow change seen in white matter hyperintensity volume and total brain volume with time. Our objective was to determine whether common carotid artery stiffness on sonography accurately predicts white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later.

MATERIALS AND METHODS

We performed a secondary analysis of the Atherosclerosis Risk in the Community study to compare 5 measurements of carotid artery stiffness, including strain, distensibility, compliance, Stiffness index, and pressure-strain elastic modulus, with the white matter hyperintensity volume and total brain volume on a follow-up MR imaging using linear regression.

RESULTS

We included 1402 patients enrolled in the Atherosclerosis Risk in the Community study. There was a significant relationship between increasing carotid artery stiffness and both higher white matter hyperintensity volume and lower total brain volume on MR imaging, measured at a mean of 21.5 years later. In multivariable linear regression models, the carotid strain, distensibility, Stiffness index, and pressure-strain elastic modulus were associated with white matter hyperintensity volume. Only compliance was associated with total brain volume in the multivariate models.

CONCLUSIONS

Sonography measurements of carotid artery stiffness are predictive of white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later. The association is more robust for white matter hyperintensity volume than total brain volume. These findings support the role of arterial stiffness as a method for identifying patients at risk of developing white matter hyperintensity volume and as a potential mechanism leading to small-artery disease of the brain.

Direct Lineage Reprogramming in the CNS

Direct lineage reprogramming is the conversion of one specialized cell type to another without the need for a pluripotent intermediate. To date, a wide variety of cell types have been successfully generated using direct reprogramming, both in vitro and in vivo. These newly converted cells have the potential to replace cells that are lost to disease and/or injury. In this chapter, we will focus on direct reprogramming in the central nervous system. We will review current progress in the field with regards to all the major neural cell types and explore how cellular heterogeneity, both in the starter cell and target cell population, may have implications for direct reprogramming. Finally, we will discuss new technologies that will improve our understanding of the reprogramming process and aid the development of more specific and efficient future CNS-based reprogramming strategies.

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.

Spatial Signature of White Matter Hyperintensities in Stroke Patients

Purpose: White matter hyperintensity (WMH) is a common phenotype across a variety of neurological diseases, particularly prevalent in stroke patients; however, vascular territory dependent variation in WMH burden has not yet been identified. Here, we sought to investigate the spatial specificity of WMH burden in patients with acute ischemic stroke (AIS). Materials and Methods: We created a novel age-appropriate high-resolution brain template and anatomically delineated the cerebral vascular territories. We used WMH masks derived from the clinical T2 Fluid Attenuated Inverse Recovery (FLAIR) MRI scans and spatial normalization of the template to discriminate between WMH volume within each subject's anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories. Linear regression modeling including age, sex, common vascular risk factors, and TOAST stroke subtypes was used to assess for spatial specificity of WMH volume (WMHv) in a cohort of 882 AIS patients. Results: Mean age of this cohort was 65.23 ± 14.79 years, 61.7% were male, 63.6% were hypertensive, 35.8% never smoked. Mean WMHv was 11.58c ± 13.49 cc. There were significant differences in territory-specific, relative to global, WMH burden. In contrast to PCA territory, age (0.018 ± 0.002, p < 0.001) and small-vessel stroke subtype (0.212 ± 0.098, p < 0.001) were associated with relative increase of WMH burden within the anterior (ACA and MCA) territories, whereas male sex (-0.275 ± 0.067, p < 0.001) was associated with a relative decrease in WMHv. Conclusions: Our data establish the spatial specificity of WMH distribution in relation to vascular territory and risk factor exposure in AIS patients and offer new insights into the underlying pathology.