White Matter Hyperintensity on Cranial Magnetic Resonance Imaging

Relationship between cognitive impairment and echocardiographic parameters: a review

With >24 million people affected worldwide, dementia is one of the main public health challenges modern medicine has to face. The path leading to dementia is often long, with a wide spectrum of clinical presentations, and preceded by a long preclinical phase. Previous studies have demonstrated that clinical strokes and covert vascular lesions of the brain contribute to the risk for developing dementia. Although it is not yet known whether preventing such lesions reduces the risk for dementia, it is likely that starting preventive measures early in the course of the disease may be beneficial. Echocardiography is a widely available, relatively inexpensive, noninvasive imaging modality whereby morphologically or hemodynamically derived parameters may be integrated easily into a risk assessment model for dementia. The aim of this review is to analyze the information that has accumulated over the past two decades on the prognostic value of echocardiographic factors in cognitive impairment. The associations between cognitive impairment and echocardiographic parameters, including left ventricular systolic and diastolic indices, left atrial morphologic parameters, cardiac output, left ventricular mass, and aortic root diameter, have previously been reported. In the light of these studies, it appears that echocardiography may help further improve currently used risk assessment models by allowing detection of subclinical cardiac abnormalities associated with future cognitive impairment. However, many limitations, including methodologic heterogeneity and the observational designs of these studies, restrict the scope of these results. Further prospective studies are required before integrating echocardiography into a preventive strategy.

Association of leukoaraiosis with stroke recurrence within 5 years after initial stroke

BACKGROUND

Leukoaraiosis (LA) is closely associated with stroke. Despite the fact that LA has consistently been shown to predict development of recurrent stroke, prior studies on the association of LA and stroke subtypes have been unsatisfactory. In this study, we sought to identify whether LA contributes to the recurrence of certain subtypes of stroke at long term.

METHODS

Data from the Ege Stroke Registry were examined, and 5 years follow-up data for LA and stroke recurrence were analyzed. We performed survival curves using the Kaplan-Meier method (unadjusted) and log-rank tests in patients with stroke to determine the relationship between LA and recurrent stroke by stroke subtypes within a time period of 5 years. Multivariate survival analyses were undertaken using Cox proportional hazards models to determine the prognostic value of LA, stroke subtypes, and other vascular risk factors before recurrent stroke.

RESULTS

Of 9522 patients with stroke, 1280 (26%) with LA and 901 (19%) without LA experienced a stroke recurrence within 5 years of follow-up (odds ratio, 1.53; 95% confidence interval, 1.39-1.69). After stratification by stroke subtypes, multivariable analysis revealed a significant association between LA and large artery disease (LAD; odds ratio [OR], 1.39; 95% confidence interval [CI], 1.18-1.64), small artery disease (SAD; OR, 1.57; 95% CI, 1.27-1.94), and intracerebral hemorrhage (ICH; OR, 1.88; 95% CI, 1.32-2.66), except cardioembolic stroke and "other" stroke subtypes at 5 years after stroke onset. The survival analysis showed that stroke recurrence was significantly higher in patients with severe LA compared with those with mild/moderate LA (log-rank test [Mantel-Cox], P < .001).

CONCLUSIONS

Our results showed that LA is related to the recurrent strokes in patients with stroke within 5 years after stroke, specifically to the LAD, SAD and ICH.

Is there an association between cerebral microbleeds and leukoaraiosis?

PURPOSE

Cerebral microbleeds (CMBs) are small dot-like lesions appearing as hyposignals on gradient echo (GRE) T2* magnetic resonance (MR) sequences, whereas the leukoaraiosis (LA) indicates the presence of patchy areas of hypersignal on fluid-attenuated inversion recovery (FLAIR) MR sequences in the periventricular white matter. The purpose of this work was to evaluate the association between LA and CMBs.

MATERIAL AND METHODS

Eighty-five consecutive (men 55; median age 64 years) patients were retrospectively analyzed using a 1.5 T system; CMBs were studied using a T2*-weighted GRE sequence and classified as absent (grade 1), mild (grade 2; total number of microbleeds, 1-2), moderate (grade 3; total number of microbleeds, 3-10), and severe (grade 4; total number of microbleeds, >10). LA was assessed with FLAIR MR sequences and was graded based on the European Task Force on Age-Related White Matter Changes as follows: 1 (no lesions), 2 (focal lesions > 5 mm), 3 (early confluent lesions), and 4 (diffuse involvement of an entire brain region).

RESULTS

We considered 170 cerebral hemispheres. The prevalence of CMBs was 24.7% (42 of 170), whereas the prevalence of LA was 27.1% (46 of 170). A statistically significant correlation was observed between LA and CMBs (correlation rho = .495, P value = .001). Multiple logistic regression analysis showed an association between CMBs and cerebrovascular symptoms (P = .0023).

CONCLUSION

Results of this study suggest an association between CMBs and LA. Moreover, we found that LA is associated with the presence of cerebrovascular symptoms.

Osteoporosis as an independent risk factor for silent brain infarction and white matter changes in men and women: the PRESENT project

SUMMARY

Previous studies have not demonstrated a relationship between osteoporosis and cerebral infarction in the community, especially in men. We found that osteoporosis may be an independent risk factor for brain white matter change/silent infarction in men, as well as in women.

PURPOSE

We aimed to study the relationship between low bone mineral density (BMD) and brain white matter changes and/or silent infarcts (WMC/SI).

METHODS

This was a community-based, cross-sectional study supported by the regional government. Bone mineral density measurements and brain computed tomography were performed in 646 stroke- and dementia-free subjects (aged 50-75 years).

RESULTS

After adjustment for age, hypertension, diabetes mellitus, dyslipidemia, and current smoking status, the odds ratio (OR) of risk for WMC and/or SI was 1.8 in the osteopenia group (95 % confidence interval [CI] 1.15-2.77; P = 0.01) and 2.2 in the osteoporosis group (95 % CI 1.42-3.55; P < 0.001). Among men, the OR was 1.8 (95 % CI 0.72-4.62; P = 0.21) and 3.8 (95 % CI 1.63-8.86; P = 0.002), and in women, the OR was 1.9 (95 % CI 1.15-2.78; P = 0.010) and 2.2 (95 % CI 1.42-3.55; P = 0.001), respectively.

CONCLUSIONS

Severe bone mass loss may be an independent risk factor for brain WMC/SI in men and women. Low BMD may cause brain WMC/SI in the step that leads to stroke. Although there are well-designed studies on the prevention of cerebral infarction in patients with brain WMC/SI, a specific prevention method, such as aspirin, should be used for patients with low BMD who have WMC/SI. Screening for low BMD as an independent vascular risk factor in healthy subjects may be required to prevent stroke.

Mammographically detectable breast arterial calcification and atherosclerosis

Breast arterial calcification (BAC), observed as an incidental finding on screening mammograms, represents degenerative calcific changes occurring in the mammary arteries, with increasing age. The aim of this review is to discuss relevant literature examining relation between BAC and atherosclerosis. After a thorough literature search, in OVID and PubMed, 199 studies were identified, of which 25 were relevant to our review. Data were abstracted from each study and statistical analysis was done, including calculation of odds ratios and construction of forest plots. A total of 35,542 patients were enrolled across 25 studies looking at an association between BAC and coronary artery disease, cardiovascular disease, stroke, cerebral artery disease, carotid and peripheral artery diseases, and coronary artery calcification. A majority of the studies showed a statistically significant relation between BAC and presence of coronary artery disease cardiovascular disease and associated mortality. Sensitivity of BAC in predicting cardiovascular events was low, but specificity was high. BAC was predictive of incident and prevalent stroke but not mortality of stroke. Similarly, BAC was predictive of cerebral, carotid, and peripheral artery diseases. The role of BAC as a surrogate marker of coronary and systemic atherosclerosis is currently uncertain. Its role may be further elucidated by more large-scale prospective studies and clinical experience.

Social engagement and physical and cognitive health among American Indian participants in the health and retirement study

Social engagement has many demonstrated benefits for aging non-Hispanic Whites in the U.S. This study examined data from the U.S. Health and Retirement Study to determine whether these benefits were similar among American Indians and Alaska Natives older than 50 years. Linear regression techniques were used to examine the associations between level of social engagement, scores for memory and mental status, and self-reported health among 203 American Indian and Alaska Native elders who participated in the Health and Retirement Study and had data available between 1998 and 2010. Level of social engagement was significantly associated with memory, mental status, and self-reported health. However, only the association of social engagement with mental status and self-reported health remained significant (p = 0.04 and p = 0.05, respectively) after adjusting for sociodemographic variables, number of known health conditions, and scores on the Center for Epidemiologic Studies Depression scale. Level of social engagement was not associated with patterns of decline across time in cognitive or physical health. Higher levels of social engagement are associated with better physical and cognitive functioning in American Indian and Alaska Native elders. Future studies should examine whether this association acts through cognitive stimulation, increase in physical activity resulting from social engagement, or access to resources that support physical and cognitive health.

Setting a gold standard for quantification of leukoaraiosis burden in patients with ischemic stroke: the Atherosclerosis Risk in Communities Study

BACKGROUND

Accurate and reliable measurement of leukoaraiosis, or MR-detected white, matter hyper-intensity (WMH) burden in subjects with acute ischemic stroke (AIS) is important for, ongoing research studies and future models of risk and outcome prediction, but the presence of a, cerebral infarct may complicate measurement. We sought to assess accuracy of a volumetric method, designed to measure WMH in AIS subjects as compared to the previously validated protocol.

NEW METHOD

We randomly selected and equally sampled 120 brain scans from the Atherosclerosis, Risk in Communities (ARIC) MRI Study individuals within designated mild, moderate, and severe, tertiles of WMH volume (WMHV). T2 FLAIR axial images were analyzed using the AIS WMH volumetric, protocol and compared with the ARIC (gold standard) method. Pearson correlation coefficients, linear, concordance correlation coefficient, and Blant–Altman procedures were used to assess measurement, agreements between the two procedures.

RESULTS

Median WMHV determined by using the ARIC method was 7.8 cm3 (IQR 5.7–13.55) vs. 3.54 cm3, (IQR 2.1–7.2) using the AIS WMH method. There was good correlation between the two measurements, (r = 0.52, 0.67, and 0.9 for tertiles 1, 2, and 3 respectively) (p < 0.001).

COMPARISON WITH EXISTING METHOD

The AIS WMH protocol was specific for leukoaraiosis in ischemic, stroke, but it appeared to underestimate WMHV compared to the gold standard method.

CONCLUSIONS

Estimates of MR-detectable WMH burden using a volumetric protocol designed for, analysis of clinical scans correlate strongly with gold standard measurements. These findings will, facilitate future studies of WMH in normal aging and in patients with stroke and other cerebrovascular, disease.

The severities of white matter lesions possibly influence the recurrences of several stroke types

BACKGROUND

White matter lesions (WML) have been reported to be a surrogate marker of stroke occurrences. To investigate the recurrent stroke types associated with WML, we prospectively observed recurrences in stroke patients.

METHODS

We prospectively analyzed the types of stroke recurrence in 807 patients (351 women, 69.8 ± 12.0 years old) consecutively admitted to our hospital with strokes from April 2004 to October 2009. WML were graded using Fazekas grades. Recurrence-free rate curves were generated by the Kaplan-Meier method using the log-rank test.

RESULTS

The follow-up period was 31.6 ± 22.2 (range .5-71) months. During this period, 111 strokes recurred. The incidence of all stroke recurrences in 223 patients with grades 2 and 3 was 6.0% per year, which was significantly higher than that seen in 287 patients with grade 0 (2.1% per year, P = .006) and 297 patients with grade 1 (4.3% per year, P < .0001). The incidences of intracerebral hemorrhages (ICHs), lacunar infarctions, and atherothrombotic infarctions in patients with grades 2 and 3 were 1.2, 1.4, and 2.4% per year, respectively, which were higher than those seen in patients with grade 0 (.3%, P = .004; .2%, P = .002; and .9% per year, P = .010) but not similar to those in patients with grade 1 (.9%, P = .180; .9%, P = .161; and 1.4% per year, P = .249). There was no significant difference among grades 0, 1, 2, and 3 in incidence of stroke recurrences presenting as cardioembolic infarctions.

CONCLUSIONS

The presence of high-grade WML elevated the rate of stroke recurrences presenting as ICHs, lacunar infarctions, and atherothrombotic infarctions but not as cardioembolic infarctions.

Cardiopulmonary fitness correlates with regional cerebral grey matter perfusion and density in men with coronary artery disease

Purpose

Physical activity is associated with positive effects on the brain but there is a paucity of clinical neuroimaging data in patients with coronary artery disease (CAD), a cardiovascular condition associated with grey matter loss. The purpose of this study was to determine which brain regions are impacted by cardiopulmonary fitness and with the change in fitness after 6 months of exercise-based cardiac rehabilitation.

Methods

CAD patients underwent magnetic resonance imaging at baseline, and peak volume of oxygen uptake during exercise testing (VO_2Peak) was measured at baseline and after 6 months of training. T1-weighted structural images were used to perform grey matter (GM) voxel-based morphometry (VBM). Pseudo-continuous arterial spin labeling (pcASL) was used to produce cerebral blood flow (CBF) images. VBM and CBF data were tested voxel-wise using VO_2Peak and age as explanatory variables.

Results

In 30 men with CAD (mean age 65±7 years), VBM and CBF identified 7 and 5 respective regions positively associated with baseline VO_2Peak. These included the pre- and post-central, paracingulate, caudate, hippocampal regions and converging findings in the putamen. VO_2Peak increased by 20% at follow-up in 29 patients (t = 9.6, df = 28, p<0.0001). Baseline CBF in the left post-central gyrus and baseline GM density in the right putamen predicted greater change in VO_2Peak.

Conclusion

Perfusion and GM density were associated with fitness at baseline and with greater fitness gains with exercise. This study identifies new neurobiological correlates of fitness and demonstrates the utility of multi-modal MRI to evaluate the effects of exercise in CAD patients.

Elevated levels of hemoglobin A1c are associated with cerebral white matter disease in patients with stroke

BACKGROUND AND PURPOSE

This study was conducted to investigate the association of cerebral white matter disease (WMD) on MRI with vascular risk factors and laboratory findings in consecutive first acute ischemic stroke patients.

METHODS

Acute ischemic stroke patients underwent MRI ≤24 hours after stroke onset and follow-up on day 2. WMD was scored on fluid attenuated inversion recovery MRI according to the Wahlund score. Vascular risk factors and laboratory parameters were assessed during hospital stay. Univariate and multiple logistic regression analyses were performed.

RESULTS

We included 512 patients with first acute ischemic stroke (mean age, 68.5 [SD, 13.2] years; 192 women (37.5%); median National Institutes of Health Stroke Scale on admission, 3 [interquartile range, 1-6]; and median Wahlund score, 4 [interquartile range, 2-9]). WMD was present in 460 (89.8%) patients. In univariate analysis, age, arterial hypertension, reduced estimated glomerular filtration rate, hemoglobin A1c (HbA1c) levels, diabetes mellitus, and female sex were associated with the presence of WMD (P<0.05). In multiple regression analysis, age, arterial hypertension, and elevated levels of HbA1c (P<0.05) remained independently associated with the extent of WMD.

CONCLUSIONS

Among known risk factors, higher levels of HbA1c were associated with cerebral WMD in stroke patients. This may suggest that chronic disturbance of glycemia measured by HbA1c plays a role in the pathophysiology of WMD.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00715533.

White matter disease as a biomarker for long-term cerebrovascular disease and dementia

OPINION STATEMENT

White matter disease is commonly detected on brain MRI of aging individuals as white matter hyperintensities (WMH), or 'leukoaraiosis." Over the years, it has become increasingly clear that the presence and extent of WMH is a radiographic marker of small cerebral vessel disease and an important predictor of the lifelong risk of stroke, cognitive impairment, and functional disability. A number of large population-based studies have outlined the significance of WMH as a biomarker for long-term cerebrovascular disease and dementia. In this review, we describe the conceptual framework and methodology that support this association and link the existing knowledge to future lines of investigation in the field.

Diabetes predicts long-term disability in an elderly urban cohort: the Northern Manhattan Study

PURPOSE

There are limited data on vascular predictors of long-term disability in Hispanics. We hypothesized that (1) functional status declines over time and (2) vascular risk factors predict functional decline.

METHODS

The Northern Manhattan Study contains a population-based study of 3298 stroke-free individuals aged 40 years or older, followed for median 11 years. The Barthel Index (BI) was assessed annually. Generalized estimating equations and Cox models were adjusted for demographic, medical, and social risk factors. Stroke and myocardial infarction occurring during follow-up were censored in sensitivity analysis. Secondarily, motor and nonmotor domains of the BI were analyzed.

RESULTS

Mean age (standard deviation) of the cohort (n = 3298) was 69.2 (10) years, 37% were male, 52% Hispanic, 22% diabetic, and 74% hypertensive. There was a mean annual decline of 1.02 BI points (P < .0001). Predictors of decline in BI included age, female sex, diabetes, depression, and normocholesterolemia. Results did not change with censoring. We found similar predictors of BI for motor and nonmotor domains.

CONCLUSION

In this large, population-based, multiethnic study with long-term follow-up, we found a 1% mean decline in function per year that did not change when vascular events were censored. Diabetes predicted functional decline in the absence of clinical vascular events.

LA volumes and reservoir function are associated with subclinical cerebrovascular disease: the CABL (Cardiovascular Abnormalities and Brain Lesions) study

OBJECTIVES

The purpose of this study was to assess the relationship of left atrial (LA) phasic volumes and LA reservoir function with subclinical cerebrovascular disease in a stroke-free community-based cohort.

BACKGROUND

An increase in LA size is associated with cardiovascular events including stroke. However, it is not known whether LA phasic volumes and reservoir function are associated with subclinical cerebrovascular disease.

METHODS

The LA minimum (LAV(min)) and maximum (LAV(max)) volumes, and LA reservoir function, measured as total emptying volume (LAEV) and total emptying fraction (LAEF), were assessed by real-time 3-dimensional echocardiography in 455 stroke-free participants from the community-based CABL (Cardiovascular Abnormalities and Brain Lesions) study. Subclinical cerebrovascular disease was assessed as silent brain infarcts (SBI) and white matter hyperintensity volume (WMHV) by brain magnetic resonance imaging.

RESULTS

Prevalence of SBI was 15.4%; mean WMHV was 0.66 ± 0.92%. Participants with SBI showed greater LAV(min) (17.1 ± 9.3 ml/m(2) vs. 12.5 ± 5.6 ml/m(2), p < 0.01) and LAV(max) (26.6 ± 8.8 ml/m(2) vs. 23.3 ± 7.0 ml/m(2), p < 0.01) compared to those without SBI. The LAEV (9.5 ± 3.4 ml/m(2) vs. 10.8 ± 3.9 ml/m(2), p < 0.01) and LAEF (38.7 ± 14.7% vs. 47.0 ± 11.9%, p < 0.01) were also reduced in participants with SBI. In univariate analyses, greater LA volumes and smaller reservoir function were significantly associated with greater WMHV. In multivariate analyses, LAV(min) remained significantly associated with SBI (adjusted odds ratio per SD increase: 1.37, 95% confidence interval: 1.04 to 1.80, p < 0.05) and with WMHV (β = 0.12, p < 0.01), whereas LAVmax was not independently associated with either. Smaller LAEF was independently associated with SBI (adjusted odds ratio: 0.67, 95% confidence interval: 0.50 to 0.90, p < 0.01) and WMHV (β = -0.09, p < 0.05).

CONCLUSIONS

Greater LA volumes and reduced LA reservoir function are associated with subclinical cerebrovascular disease detected by brain magnetic resonance imaging in subjects without history of stroke. In particular, LAV(min) and LAEF are more strongly associated with SBI and WMHV than the more commonly measured LAVmax, and their relationship with subclinical brain lesions is independent of other cardiovascular risk factors.

Imaging small vessel-associated white matter changes in aging

Alterations in cerebrovascular structure and function may underlie the most common age-associated cognitive, psychiatric, and neurological conditions presented by older adults. Although much remains to understand, existing research suggests several age-associated detrimental conditions may be mediated through sometimes subtle small vessel-induced damage to the cerebral white matter. Here we review a selected portion of the vast work that demonstrates links between changes in vascular and neural health as a function of advancing age, and how even changes in low-to-moderate risk individuals, potentially beginning early in the adult age-span, may have an important impact on functional status in late life.

Genetics of ischaemic stroke

Recent advances in genomics and statistical computation have allowed us to begin addressing the genetic basis of stroke at a molecular level. These advances are at the cusp of making important changes to clinical practice of some monogenic forms of stroke and, in the future, are likely to revolutionise the care provided to these patients. In this review we summarise the state of knowledge in ischaemic stroke genetics particularly in the context of how a practicing clinician can best use this knowledge.

Population-based case-control study of white matter changes on brain imaging in transient ischemic attack and ischemic stroke

BACKGROUND AND PURPOSE

White matter changes (WMC) are a common finding on brain imaging and are associated with an increased risk of ischemic stroke. They are most frequent in small vessel stroke; however, in the absence of comparisons with normal controls, it is uncertain whether WMC are also more frequent than expected in other stroke subtypes. Therefore, we compared WMC in pathogenic subtypes of ischemic stroke versus controls in a population-based study.

METHODS

We evaluated the presence and severity of WMC on computed tomography and on magnetic resonance brain imaging using modified Blennow/Fazekas scale and age-related white matter changes scale, respectively, in a population-based study of patients with incident transient ischemic attack or ischemic stroke (Oxford Vascular Study) and in a study of local controls (Oxford Project to Investigate Memory and Ageing) without history of transient ischemic attack or ischemic stroke, with stratification by stroke pathogenesis (Trial of Org10172 in Acute Stroke Treatment classification).

RESULTS

Among 1601 consecutive eligible patients with first-ever ischemic events, 1453 patients had computed tomography brain imaging, 562 had magnetic resonance imaging, and 414 patients had both. Compared with 313 controls (all with computed tomography and 131 with magnetic resonance imaging) and after adjustment for age, sex, diabetes mellitus, and hypertension, moderate/severe WMC (age-related white matter changes scale) were more frequent in patients with small vessel events (odds ratio, 3.51 [95% confidence interval, 2.13-5.76]; P<0.0001) but not in large artery (odds ratio, 1.03 [95% confidence interval, 0.64-1.67]), cardioembolic (odds ratio, 0.87 [95% confidence interval, 0.56-1.34]), or undetermined (odds ratio, 0.90 [95% confidence interval, 0.62-1.30]) subtypes. Results were consistent for ischemic stroke and transient ischemic attack, for other scales, and for magnetic resonance imaging and computed tomography separately.

CONCLUSIONS

In contrast to small vessel ischemic events, WMC were not independently associated with other pathogenic subtypes, suggesting that WMC are unlikely to be an independent risk factor for nonsmall vessel events.

Investigation of the Risk Factors for Leukoaraiosis (LA)

Leukoaraiosis (LA) describes abnormal changes in the cerebral white matter frequently seen on CT and MRI in older adults. Its appearance indicates mild brain injury, and it is often regarded as a mark of senile dementia. Through the analysis of related risk factors of 6000 patients with LA diagnosed by cranial MRI in our department, we found that age, cerebral infarction, lacunar infarction, history of brain hemorrhage, and increased triglycerides were risk factors for LA, and the relative risk odds ratio values were 2.135 (95% confidence interval [CI] = 1.874-2.501), 3.330 (95% CI = 1.922-3.997), 3.412 (95% CI = 2.986-3.512), 3.611 (95% CI = 2.054-9.147), and 1.457 (95% CI = 1.058-1.769), respectively. Through the identification of the risk factors for LA and effective interventions, the occurrence of dementia, stroke, and premature death may be effectively prevented.

Progress towards a consensus on biomarkers for Alzheimer’s disease: a review of peripheral analytes

Alzheimer’s disease (AD) is the most common cause of dementia in the elderly population and attempts to develop therapies have been unsuccessful because there is no means to target an effective therapeutic window. CNS biomarkers are insightful but impractical for high-throughput population-based screening. Therefore, a peripheral, blood-based biomarker for AD would significantly improve early diagnosis, potentially enable presymptomatic detection and facilitate effective targeting of disease-modifying treatments. The various constituents of blood, including plasma, platelets and cellular fractions, are now being systematically explored as a pool of putative peripheral biomarkers for AD. In this review we cover some less known peripheral biomarkers and highlight the latest developments for their clinical application.

Subclinical left ventricular dysfunction and silent cerebrovascular disease: the Cardiovascular Abnormalities and Brain Lesions (CABL) study

BACKGROUND

Silent brain infarcts (SBIs) and white matter hyperintensities are subclinical cerebrovascular lesions associated with incident stroke and cognitive decline. Left ventricular ejection fraction (LVEF) is a predictor of stroke in patients with heart failure, but its association with subclinical brain disease in the general population is unknown. Left ventricular global longitudinal strain (GLS) can detect subclinical cardiac dysfunction even when LVEF is normal. We investigated the relationship of LVEF and GLS with subclinical brain disease in a community-based cohort.

METHODS AND RESULTS

LVEF and GLS were assessed by 2-dimensional and speckle-tracking echocardiography in 439 participants free of stroke and cardiac disease from the Cardiovascular Abnormalities and Brain Lesions (CABL) study. SBIs and white matter hyperintensities were assessed by brain MRI. Mean age of the study population was 69±10 years, 61% were women, LVEF was 63.8±6.4%, GLS was -17.1±3.0%. SBIs were detected in 53 participants (12%), white matter hyperintensity volume was 0.63±0.86%. GLS was significantly lower in participants with SBI versus those without (-15.7±3.5% versus -17.3±2.9%, P<0.01), whereas no difference in LVEF was observed (63.3±8.6% versus 63.8±6.0%, P=0.60). In multivariate analysis, lower GLS was associated with SBI (odds ratio/unit decrease=1.18; 95% confidence interval, 1.05-1.33; P<0.01), whereas LVEF was not (odds ratio/unit increase=1.00; 95% confidence interval, 0.96-1.05; P=0.98). Lower GLS was associated with greater white matter hyperintensity volume (adjusted β=0.11, P<0.05), unlike LVEF (adjusted β=-0.04, P=0.42).

CONCLUSIONS

Lower GLS was independently associated with subclinical brain disease in a community-based cohort without overt cardiac disease. GLS can provide additional information on cerebrovascular risk burden beyond LVEF assessment.

Protected stent-assisted carotid angioplasty in symptomatic high-risk NASCET-ineligible patients

BACKGROUND AND OBJECTIVES

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) excluded patients with severe medical, angiographic and neurological risk factors. The aim of this study is to determine the safety and efficacy of protected stent angioplasty in these high-risk patients.

METHODS

Sixty-eight consecutive symptomatic NASCET-ineligible patients underwent protected stent-assisted carotid angioplasty. Patients were classified according to surgical risk based on Sundt criteria, and stratified for medical therapy according to stroke risk. Twenty-one patients were classified as Sundt grade 3 (30.8%) and 36 patients as grade 4 (52.9%).

RESULTS

The procedure was technically successful in all patients, with stenosis averaging 82.1% (range 70-99%) before the procedure and 6.3% (range 0-30%) after treatment. There were no periprocedural deaths or major strokes, but two patients had minor, non-embolic stokes (2.9%). During a mean clinical follow-up of 14.4 months (range 1-30 months), no new neurological events occurred in relation to the treated vascular territory.

CONCLUSIONS

Carotid angioplasty with cerebral protection can be performed safely in high-risk patients. During the follow-up period, angioplasty was highly effective in terms of stroke prevention and arterial patency.

Automated white matter total lesion volume segmentation in diabetes

BACKGROUND AND PURPOSE

WM lesion segmentation is often performed with the use of subjective rating scales because manual methods are laborious and tedious; however, automated methods are now available. We compared the performance of total lesion volume grading computed by use of an automated WM lesion segmentation algorithm with that of subjective rating scales and expert manual segmentation in a cohort of subjects with type 2 diabetes.

MATERIALS AND METHODS

Structural T1 and FLAIR MR imaging data from 50 subjects with diabetes (age, 67.7 ± 7.2 years) and 50 nondiabetic sibling pairs (age, 67.5 ± 9.4 years) were evaluated in an institutional review board-approved study. WM lesion segmentation maps and total lesion volume were generated for each subject by means of the Statistical Parametric Mapping (SPM8) Lesion Segmentation Toolbox. Subjective WM lesion grade was determined by means of a 0-9 rating scale by 2 readers. Ground-truth total lesion volume was determined by means of manual segmentation by experienced readers. Correlation analyses compared manual segmentation total lesion volume with automated and subjective evaluation methods.

RESULTS

Correlation between average lesion segmentation and ground-truth total lesion volume was 0.84. Maximum correlation between the Lesion Segmentation Toolbox and ground-truth total lesion volume (ρ = 0.87) occurred at the segmentation threshold of k = 0.25, whereas maximum correlation between subjective lesion segmentation and the Lesion Segmentation Toolbox (ρ = 0.73) occurred at k = 0.15. The difference between the 2 correlation estimates with ground-truth was not statistically significant. The lower segmentation threshold (0.15 versus 0.25) suggests that subjective raters overestimate WM lesion burden.

CONCLUSIONS

We validate the Lesion Segmentation Toolbox for determining total lesion volume in diabetes-enriched populations and compare it with a common subjective WM lesion rating scale. The Lesion Segmentation Toolbox is a readily available substitute for subjective WM lesion scoring in studies of diabetes and other populations with changes of leukoaraiosis.

An updated definition of stroke for the 21st century: a statement for healthcare professionals from the American Heart Association/American Stroke Association

Despite the global impact and advances in understanding the pathophysiology of cerebrovascular diseases, the term "stroke" is not consistently defined in clinical practice, in clinical research, or in assessments of the public health. The classic definition is mainly clinical and does not account for advances in science and technology. The Stroke Council of the American Heart Association/American Stroke Association convened a writing group to develop an expert consensus document for an updated definition of stroke for the 21st century. Central nervous system infarction is defined as brain, spinal cord, or retinal cell death attributable to ischemia, based on neuropathological, neuroimaging, and/or clinical evidence of permanent injury. Central nervous system infarction occurs over a clinical spectrum: Ischemic stroke specifically refers to central nervous system infarction accompanied by overt symptoms, while silent infarction by definition causes no known symptoms. Stroke also broadly includes intracerebral hemorrhage and subarachnoid hemorrhage. The updated definition of stroke incorporates clinical and tissue criteria and can be incorporated into practice, research, and assessments of the public health.

Vascular cognitive impairment

PURPOSE OF REVIEW

Clinically apparent and subclinical forms of vascular disease including stroke are important causes of cognitive dysfunction. In this review, we will describe the current nomenclature for vascular cognitive impairment (VCI) from the histopathological and clinical perspectives to raise awareness among practitioners about the interaction between conventional and novel vascular risk factors and VCI, with an emphasis on the prevention and risk factor modification.

RECENT FINDINGS

There is substantial evidence from observational studies and clinical trials that conventional risk factors such as hypertension, diabetes, dyslipidemia, smoking, and atrial fibrillation play a role in the development of VCI. Additional novel risk factors such as the metabolic syndrome have been associated with cognitive dysfunction as well. Targeting these risk factors will minimize the burden of VCI in our aging population.

SUMMARY

The concept of VCI has evolved to describe a continuum of cognitive disorders in which vascular brain injury plays a role, ranging from mild cognitive impairment to dementia. Future research is needed to clarify the role of risk factor modification in limiting vascular brain injury to prevent VCI and progression to dementia.

Magnetic resonance imaging to visualize stroke and characterize stroke recovery: a review

The global burden of stroke continues to grow. Although stroke prevention strategies (e.g., medications, diet, and exercise) can contribute to risk reduction, options for acute interventions (e.g., thrombolytic therapy for ischemic stroke) are limited to the minority of patients. The remaining patients are often left with profound neurological disabilities that substantially impact quality of life, economic productivity, and increase caregiver burden. In the last decade, however, the future outlook for such patients has been tempered by movement toward the view that the brain is capable of reorganizing after injury. Many now view brain recovery after stroke as an area of scientific research with large potential for therapeutic advances, far into the future (Broderick and William, 2004). As a probe of brain anatomy, function and physiology, magnetic resonance imaging (MRI) is a non-invasive and highly versatile modality that promises to play a particularly important role in such research. Here we provide a basic review of MRI physical principles and applications for assessing stroke, looking toward the future role MRI may play in improving stroke rehabilitation methods and stroke recovery.

Leukoaraiosis on MRI in patients with minimally symptomatic obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is associated with hypertension, nocturnal blood pressure (BP) surges, and increased risk of stroke. It may therefore also be associated with a higher risk of developing leukoaraiosis. Only few data about the prevalence of leukoaraiosis in patients with OSA, and any association between degrees of severity of either condition, exist.

METHODS

We studied patients who were part of a clinical trial (MOSAIC) in minimally symptomatic OSA. All patients had brain MRI (T2, FLAIR) at baseline. A single observer assessed the images for the presence and severity of leukoaraiosis (ARWMC-score). We related the extent of leukoaraiosis to the severity of OSA (measured by oxygen desaturation index [ODI]) and the presence of other vascular risk factors.

RESULTS

183 patients (156 men, 85.2%; mean age ± SD = 57.7 ± 7.4 years; median oxygen desaturation index = 9.6, interquartile range = 4.6-16.0) took part in the study. Although 135 (74%) patients had some leukoaraiosis, this was generally mild. We confirmed the well-known risk factor associations between leukoaraiosis, increasing age (p < 0.0001) and hypertension (p = 0.003), but we did not find any association between OSA and leukoaraiosis (p = 0.33), despite both conditions being associated with increasing current BP and a history of hypertension.

CONCLUSION

Our data confirm the well-known association between leukoaraiosis, age and increasing BP. However, we found no association between OSA and leukoaraiosis despite some shared risk factor associations. Our findings suggest that OSA is not a strong independent risk factor for leukoaraiosis. Confounding by hypertension may explain any apparent association in previously reported studies of patients with severer OSA.

Hypertension and mild cognitive impairment

The brain is an early target for organ damage due to high blood pressure. Hypertension is the major modifiable risk factor for stroke and small vessel disease. It has been suggested that cerebral microvascular disease contributes to vascular cognitive impairment. The mechanisms underlying hypertension-related cognitive changes are complex and not yet fully understood. Both high and, especially in the elderly, low blood pressure (BP) have been linked to cognitive decline and dementia. There is some evidence that antihypertensive drug treatment could play a role in the prevention of cognitive impairment through BP control. The BP levels that should be targeted to achieve optimal perfusion while preventing cognitive decline are still under debate.

Changes in plasma amyloid beta in a longitudinal study of aging and Alzheimer's disease

BACKGROUND

A practical biomarker is required to facilitate the preclinical diagnosis of Alzheimer's disease (AD).

METHODS

Plasma amyloid beta (Aβ)1-40, Aβ1-42, Aβn-40, and Aβn-42 peptides were measured at baseline and after 18 months in 771 participants from the Australian Imaging Biomarkers and Lifestyle (AIBL) study of aging. Aβ peptide levels were compared with clinical pathology, neuroimaging and neuropsychological measurements.

RESULTS

Although inflammatory and renal function covariates influenced plasma Aβ levels significantly, a decrease in Aβ1-42/Aβ1-40 was observed in patients with AD, and was also inversely correlated with neocortical amyloid burden. During the 18 months, plasma Aβ1-42 decreased in subjects with mild cognitive impairment (MCI) and in those transitioning from healthy to MCI.

CONCLUSION

Our findings are consistent with a number of published plasma Aβ studies and, although the prognostic value of individual measures in any given subject is limited, the diagnostic contribution of plasma Aβ may demonstrate utility when combined with a panel of peripheral biomarkers.

INtensive versus standard ambulatory blood pressure lowering to prevent functional DeclINe in the ElderlY (INFINITY)

Reductions in mobility and cognitive function linked to accrual of brain microvascular disease related white matter hyperintensities (WMHs) on magnetic resonance imaging can occur in older hypertensive patients in as little as 2 years. We have designed a trial evaluating 2 levels of ambulatory blood pressure (ABP) control in individuals with normal or mildly impaired mobility and cognition who have detectable cerebrovascular disease (>0.5% WMH fraction of intracranial volume) on functional outcomes. The study is a prospective randomized, open-label trial with blinded end points, in patients ages ≥75 years with elevated 24-hour systolic blood pressure (BP) (145 mm Hg in the untreated state) who do not have unstable cardiovascular disease, heart failure, or stroke. The primary and key secondary outcomes in the trial are change from baseline in mobility and cognitive function and damage to brain white matter as demonstrated by accrual of WMH volume and changes in diffusion tensor imaging. Approximately 300 patients will be enrolled, and 200 randomized to 1 of 2 levels of ABP control (intensive to achieve a goal 24-hour systolic BP of ≤130 mm Hg or standard to achieve a goal 24-hour systolic BP of ≤145 mm Hg) for a total of 36 months using similar antihypertensive regimens. The analytical approach provides 85% power to show a clinically meaningful effect in differences in mobility accompanied by quantitative differences in WMH between treatment groups. The INFINITY trial is the first to guide antihypertensive therapy using ABP monitoring rather than clinic BP to reduce cerebrovascular disease.

Leukoaraiosis on Magnetic Resonance Imaging Correlates With Worse Outcomes After Spontaneous Intracerebral Hemorrhage

Background and Purpose—

Leukoaraiosis (LA) is associated with dementia, ischemic stroke, and intracerebral hemorrhage (ICH), but there are few data on how LA might impact outcomes after acute ICH. We tested the hypothesis that the severity of LA on magnetic resonance imaging is related to worse functional outcomes after spontaneous ICH.

Methods—

We prospectively identified patients with spontaneous acute ICH. LA was identified on magnetic resonance imaging and its severity was graded using the Fazekas method to include a score for the deep white matter and periventricular regions. Outcomes were obtained at 14 days, 28 days, and 3 months with the modified Rankin Scale (mRS; a validated scale from 0 [no symptoms] to 6 [dead]) and analyzed with multivariate logistic regression.

Results—

Higher Fazekas total (periventricular plus deep white matter) score correlated with higher mRS score at 14 days ( P =0.02) and 3 months ( P =0.02). This relationship was driven by the periventricular score, for which higher score (more severe disease) correlated with higher National Institute of Health Stroke Scale at 14 days ( P =0.03), and higher mRS score at 14 days ( P <0.001), 28 days ( P =0.004), and 3 months ( P =0.005). A higher (more severe) Fazekas periventricular score was associated with dependence or death at 3 months (odds ratio, 1.8 per point; 95% confidence interval, 1.02–3.1; P =0.04) after correction for the ICH score.

Conclusions—

Increased LA is an independent predictor of worse functional outcomes in patients after spontaneous ICH. The pathophysiology associating LA with worse outcomes requires further study. These data may improve prognostication and selection for clinical trials.

Leukoaraiosis and NIHSS score help to differentiate subtypes of intracranial branch atheromatous disease in Southern Han Chinese patients with stroke

Intracranial branch atheromatous disease (BAD) includes infarcts in the territories of the lenticulostriate arteries (LSA) and paramedian pontine arteries (PPA). The two subtypes of BAD are commonly underused in clinical practice and research. We assessed the clinicoradiologic characteristics of BAD-stroke patients in LSA territories and compared with those of BAD-stroke patients in PPA territories to investigate whether there is a close relationship between leukoaraiosis (LA) and BAD in Southern Han Chinese patients. According to the lesions present in different vascular distributions as shown by diffusion-weighted imaging (DWI), a total of 220 patients diagnosed with BAD, selected from a cohort of 1,458 consecutive patients with acute ischemic stroke, were classified into LSA and PPA groups, comprising 163 and 57 patients, respectively. The characteristics of the patients with BAD were analyzed and differences between the two groups were compared. A high prevalence of concomitant LA (n = 190, 86.36 % of patients with BAD) was observed in the cohort study. Patients in the PPA group had a significantly higher National Institutes of Health Stroke Scale (NIHSS) score on admission than those in the LSA group [6 (4-8) versus 5 (3-7); p = 0.031], and there was a higher prevalence of concomitant LA in the PPA group than the LSA group (96.4 versus 82.8 %; p = 0.010). Conversely, when the number of patients with LA grades ≥ 4 was evaluated, individuals in the LSA group were more frequently affected than those in the PPA group (47.9 versus 31.6 %; p = 0.033). LA showed a high prevalence in Southern Han Chinese patients with BAD. Patients in the LSA group were significantly different from those in the PPA group with respect to NIHSS score, LA and LA grade.

Significance of increased CIMT with coexisting carotid plaques in cerebral white matter lesions in elders

It is very common that increased carotid intima media thickness (CIMT) and carotid plaque coexist in a single subject in elderly patients with white matter lesions (WMLs). In this study we investigated whether the coexistence of increased CIMT and carotid plaque is more strongly associated with the presence and extent of WMLs than either alone. All patients were classified into 1 of the following 4 groups: without either increased CIMT (I) or carotid plaque (P): I(-)P(-); with only increased CIMT: I(+)P(-); with only carotid plaque: I(-)P(+); and with both increased CIMT and carotid plaque: I(+)P(+). The presence and severity of periventricular WMLs (PWMLs) and deep WMLs (DWMLs) were assessed and the prevalence of MRI findings by the Cochran-Armitage trend test was calculated. The characteristics of subjects showed that the percentages of patients with increased CIMT and carotid plaque in the DWMLs group and the PWMLs group were significantly higher than those without WMLs group. Both DWMLs and PWMLs were strongly associated with age, carotid plaque and CIMT. Furthermore, the Cochran-Armitage trend test indicated that the prevalence of MRI findings of PWMLs and DWMLs increased in the order of I(-)P(-)< I(+)P(-)< I(-)P(+)< I(+)P(+) (P<0.0001). For the patients with DWMLs, the grades of both I(+)P(-) and I(+)P(+) were increased significantly compared to I(-)P(-) (P<0.0025, P<0.05, respectively) without such a difference found in patients with PWMLs. Our results suggested that the coexistence of increased CIMT and carotid plaque is most closely associated with WMLs, and that increased CIMT is associated with the severity of DWMLs, whereas carotid plaque is related to the presence of WMLs.

Contrast-based fully automatic segmentation of white matter hyperintensities: method and validation

White matter hyperintensities (WMH) on T2 or FLAIR sequences have been commonly observed on MR images of elderly people. They have been associated with various disorders and have been shown to be a strong risk factor for stroke and dementia. WMH studies usually required visual evaluation of WMH load or time-consuming manual delineation. This paper introduced WHASA (White matter Hyperintensities Automated Segmentation Algorithm), a new method for automatically segmenting WMH from FLAIR and T1 images in multicentre studies. Contrary to previous approaches that were based on intensities, this method relied on contrast: non linear diffusion filtering alternated with watershed segmentation to obtain piecewise constant images with increased contrast between WMH and surroundings tissues. WMH were then selected based on subject dependant automatically computed threshold and anatomical information. WHASA was evaluated on 67 patients from two studies, acquired on six different MRI scanners and displaying a wide range of lesion load. Accuracy of the segmentation was assessed through volume and spatial agreement measures with respect to manual segmentation; an intraclass correlation coefficient (ICC) of 0.96 and a mean similarity index (SI) of 0.72 were obtained. WHASA was compared to four other approaches: Freesurfer and a thresholding approach as unsupervised methods; k-nearest neighbours (kNN) and support vector machines (SVM) as supervised ones. For these latter, influence of the training set was also investigated. WHASA clearly outperformed both unsupervised methods, while performing at least as good as supervised approaches (ICC range: 0.87–0.91 for kNN; 0.89–0.94 for SVM. Mean SI: 0.63–0.71 for kNN, 0.67–0.72 for SVM), and did not need any training set.

Anatomic brain disease in hemodialysis patients: a cross-sectional study

BACKGROUND

Although dialysis patients are at high risk of stroke and have a high burden of cognitive impairment, there are few reports of anatomic brain findings in the hemodialysis population. Using magnetic resonance imaging of the brain, we compared the prevalence of brain abnormalities in hemodialysis patients with that in a control population without known kidney disease.

STUDY DESIGN

Cross-sectional cohort.

SETTING & PARTICIPANTS

45 maintenance hemodialysis patients and 67 controls without reported kidney disease, both without history of known stroke.

PREDICTOR

The primary predictor was dialysis status. Covariates included demographics (age, race, and sex), vascular risk factors (diabetes and hypertension), and cardiovascular disease (coronary artery disease and congestive heart failure).

OUTCOMES

Magnetic resonance imaging of the brain features, including severity of white matter disease and cerebral atrophy (sulcal prominence and ventricular atrophy), hippocampal size, and small-/large-vessel infarcts.

MEASUREMENTS

Semiquantitative scale (0-9 for white matter disease and cerebral atrophy, 0-3 for hippocampal size) and infarct prevalence.

RESULTS

Mean ages of hemodialysis patients and controls were 55 ± 17 (SD) and 53 ± 13 years, respectively. In comparison to controls, hemodialysis patients had more severe white matter disease (1.6 vs 0.7) and cerebral atrophy (sulcal prominence, 2.3 vs 0.6; ventricular enlargement, 2.3 vs 0.9; hippocampal size, 1.3 vs 1.0), with all P < 0.001. In multivariable analyses, hemodialysis status was associated independently with worse white matter disease and atrophy grades. Hemodialysis patients also had a higher prevalence of small- (17.8%) and large- (7.8%) vessel infarcts than controls (combined, 22% vs 0%; P < 0.001).

LIMITATIONS

The dialysis cohort likely is healthier than the overall US hemodialysis population, partly limiting generalizability.

CONCLUSIONS

Hemodialysis patients have more white matter disease and cerebral atrophy compared with controls without known kidney disease. Hemodialysis patients also have a high prevalence of unrecognized infarcts.

Current status and future perspectives of magnetic resonance high-field imaging: a summary

There are several magnetic resonance (MR) imaging techniques that benefit from high-field MR imaging. This article describes a range of novel techniques that are currently being used clinically or will be used in the future for clinical purposes as they gain popularity. These techniques include functional MR imaging, diffusion tensor imaging, cortical thickness assessment, arterial spin labeling perfusion, white matter hyperintensity lesion assessment, and advanced MR angiography.

Different impacts of blood pressure variability on the progression of cerebral microbleeds and white matter lesions

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMB) and white matter lesions (WML) are cerebral small vessel diseases. Hypertension is considered the most important risk factor. Its mechanism is not yet clarified. Our study assessed the association of blood pressure variability (BPV) with CMB and WML progression.

METHODS

Patients with a history of ischemic stroke within 1 to 6 months were consecutively recruited and followed-up for 12 to 18 months. Blood pressure was measured monthly and controlled to a target level. BPV was quantified by the maximum, standard deviation, coefficient of variation, successive variation, standard deviation independent of mean, and successive variation independent of mean. Magnetic resonance imaging was performed at baseline and the end of the study. CMB and WML were rated using Microbleed Anatomic Rating Scale and Age-Related White Matter Changes scales, respectively. Multiple logistic analyses assessed BPV associations with CMB and WML development.

RESULTS

Of 720 patients recruited, 500 and 584 had follow-up results for CMB and WML, respectively; 13.2% and 48.1% showed CMB and WML progression, respectively, over a median of 14 months. Patients with CMB had a higher mean, maximum, standard deviation, coefficient of variation, successive variation, standard deviation independent of the mean, and successive variation independent of the mean in either systolic blood pressure or diastolic blood pressure (P<0.05). Systolic blood pressure variability was an independent risk factor for deep and infratentorial CMB progression, whereas diastolic blood pressure variability was independently associated with CMB development in deep regions. WML progression was not significantly associated with BPV between visits.

CONCLUSIONS

BPV independently predicts CMB progression in deep and infratentorial regions.

CLINICAL TRIAL REGISTRATION INFORMATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00202020.

Deep versus periventricular white matter lesions and cognitive function in a community sample of middle-aged participants

The association of cerebral white matter lesions (WMLs) with cognitive status is not well understood in middle-aged individuals. Our aim was to determine the specific contribution of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) to cognitive function in a community sample of asymptomatic participants aged 50 to 65 years. One hundred stroke- and dementia-free adults completed a comprehensive neuropsychological battery and brain MRI protocol. Participants were classified according to PVH and DWMH scores (Fazekas scale). We dichotomized our sample into low grade WMLs (participants without or with mild lesions) and high grade WMLs (participants with moderate or severe lesions). Analyses were performed separately in PVH and DWMH groups. High grade DWMHs were associated with significantly lower scores in executive functioning (-0.45 standard deviations [SD]), attention (-0.42 SD), verbal fluency (-0.68 SD), visual memory (-0.52 SD), visuospatial skills (-0.79 SD), and psychomotor speed (-0.46 SD). Further analyses revealed that high grade DWMHs were also associated with a three- to fourfold increased risk of impaired scores (i.e.,<1.5 SD) in executive functioning, verbal fluency, visuospatial skills, and psychomotor speed. Our findings suggest that only DWMHs, not PVHs, are related to diminished cognitive function in middle-aged individuals. (JINS, 2012, 18, 1-12).

Kidney Function and White Matter Disease in Young Stroke Patients

Background and Purpose—

Impaired kidney function is thought to be associated with small vessel disease, outcome, and mortality in the general stroke population. Data are limited regarding young patients. The aim of this study was to investigate the association of kidney function and white matter hyperintensities (WMHs) in young patients with first ischemic stroke.

Methods—

We analyzed 2500 young (18–55 years) patients with first-ever ischemic stroke from the prospective observational Stroke in Young Fabry Patients (SIFAP1) study with available MRI data on WMH. Of these, 2009 had available data concerning estimated glomerular filtration rate (eGFR). Kidney function was expressed as eGFR by the Modification of Diet in Renal Disease method. Deep WMHs on MRI were classified by the Fazekas score. Multivariate analysis was performed using a regression model with random effects.

Results—

Mean eGFR was 96.7 mL/min in those with WMH Grade 0 to 1 (none to mild), 90.7 mL/min in WMH Grade 2 (moderate), and 89 mL/min in WMH Grade 3 (severe). Univariate analysis revealed WMH to be associated with age ( P <0.001), hypertension ( P <0.001), cardiovascular disease ( P =0.015), overweight (body mass index >25 kg/m 2 ; P =0.013), current smoking ( P =0.044), and eGFR ( P =0.009). In multivariate analysis, age, hypertension, and eGFR remained associated with WMH severity.

Conclusions—

In young patients with acute ischemic stroke, lower eGFR values in the normal range are associated with the presence of moderate to severe WMH.

Clinical Trial Registration—

URL: http://clinicaltrials.gov . Unique Identifier: NCT00414583.

Cerebral white matter hyperintensity in African Americans and European Americans with type 2 diabetes

Previous studies involving inner city populations detected higher cerebral white matter hyperintensity (WMH) scores in African Americans (AAs) compared with European Americans (EAs). This finding might be attributable to the higher prevalence of cardiovascular disease (CVD) risk factors and poorer access to healthcare in AAs. Despite racial differences in CVD risk factor profiles, AAs have paradoxically lower levels of subclinical CVD. We hypothesized that AAs with diabetes and good access to healthcare would have comparable or lower levels of WMH as EAs. Racial differences in the distribution of WMH were analyzed in 46 AAs and 156 EAs with type 2 diabetes enrolled in the Diabetes Heart Study (DHS)-Mind, and replicated in a sample of 113 AAs and 61 EAs patients who had clinically indicated cerebral magnetic resonance imaging. Wilcoxon 2-sample tests and linear models were used to compare the distribution of WMH in AAs and EAs and to test for association between WMH and race. The unadjusted mean WMH score from the Diabetes Heart Study-Mind was 1.9 in AAs and 2.3 in EAs (P = .3244). Among those with clinically indicated magnetic resonance imaging, the mean WMH score was 2.9 in AAs and 3.9 in EAs (P = .0503). Adjustment for age and sex produced no statistically significant differences in WMH score between AAs and EAs. These independent datasets reveal comparable WMH scores in AAs and EAs, suggesting that disparities in access to healthcare and environmental exposures likely underlie the previously reported excess burden of WMH in AAs.

Leukoaraiosis predicts parenchymal hematoma after mechanical thrombectomy in acute ischemic stroke

BACKGROUND AND PURPOSE

The purpose of this study was to determine whether leukoaraiosis (LA) predicts hemorrhagic transformation and poor outcome in patients with acute ischemic stroke treated by mechanical thrombectomy.

METHODS

We retrospectively analyzed patients with anterior circulation stroke treated with Merci devices and identified LA in the deep white matter (DWM) and periventricular white matter on the preintervention MR images. We dichotomized patients into those with moderate or severe LA in the DWM versus those without. Hemorrhage rates and outcomes were evaluated between 2 groups. We analyzed the association of moderate or severe LA with hemorrhagic transformation and poor outcome.

RESULTS

Twenty-six of 105 patients had moderate or severe LA in the DWM. Patients with moderate or severe LA in the DWM were older, had more severe neurological deficits and worse outcome, had higher rates of hemorrhagic transformation and parenchymal hematoma, but had equivalent rates of hemorrhagic infarct and subarachnoid hemorrhage when compared with those without. Patients with only periventricular LA did not have a higher rate of parenchymal hematoma. Moderate or severe LA in the DWM was an independent predictor of hemorrhagic transformation (OR, 3.4; P=0.019) and parenchymal hematoma (OR, 6.3; P=0.005). Patients with parenchymal hematoma were less often independent (modified Rankin Scale≤2, 3.8% versus 32.5%; P=0.003) and had greater in-hospital mortality (50% versus 10.4%; P<0.001).

CONCLUSIONS

Moderate or severe LA in the DWM increases the risk of parenchymal hematoma after Merci thrombectomy for patients with acute stroke. These findings require validation in a larger prospective study.

White matter lesions and brain gray matter volume in cognitively normal elders

Cerebral white matter lesions (WMLs) reflect small vessel disease, are common in elderly individuals, and are associated with cognitive impairment. We sought to determine the relationships between WMLs, age, gray matter (GM) volume, and cognition in the Cardiovascular Health Study (CHS). From the Cardiovascular Health Study we selected 740 cognitively normal controls with a 1.5 T magnetic resonance imaging (MRI) scan of the brain and a detailed diagnostic evaluation. WML severity was determined using a standardized visual rating system. GM volumes were analyzed using voxel-based morphometry implemented in the Statistical Parametric Mapping software. WMLs were inversely correlated with GM volume, with the greatest volume loss in the frontal cortex. Age-related atrophy was observed in the hippocampus and posterior cingulate cortex. Regression analyses revealed links among age, APOE*4 allele, hypertension, WMLs, GM volume, and digit symbol substitution test scores. Both advancing age and hypertension predict higher WML load, which is itself associated with GM atrophy. Longitudinal data are needed to confirm the temporal sequence of events leading to a decline in cognitive function.

Mediterranean diet and white matter hyperintensity volume in the Northern Manhattan Study

OBJECTIVE

To examine the association between a Mediterranean-style diet (MeDi) and brain magnetic resonance imaging white matter hyperintensity volume (WMHV).

DESIGN

A cross-sectional analysis within a longitudinal population-based cohort study. A semiquantitative food frequency questionnaire was administered, and a score (range, 0-9) was calculated to reflect increasing similarity to the MeDi pattern.

SETTING

The Northern Manhattan Study.

PARTICIPANTS

A total of 1091 participants, of whom 966 had dietary information (mean age, 72 years; 59.3% women, 64.6% Hispanic, 15.6% white, and 17.5% black).

MAIN OUTCOME MEASURES

The WMHV was measured by quantitative brain magnetic resonance imaging. Linear regression models were constructed to examine the association between the MeDi score and the log-transformed WMHV as a proportion of total cranial volume, controlling for sociodemographic and vascular risk factors.

RESULTS

On the MeDi scale, 11.6% scored 0 to 2, 15.8% scored 3, 23.0% scored 4, 23.5% scored 5, and 26.1% scored 6 to 9. Each 1-point increase in MeDi score was associated with a lower log WMHV (β = -.04, P = .01). The only MeDi score component that was an independent predictor of WMHV was the ratio of monounsaturated to saturated fat (β = -.20, P = .001).

CONCLUSIONS

A MeDi was associated with a lower WMHV burden, a marker of small vessel damage in the brain. However, white matter hyperintensities are etiologically heterogenous and can include neurodegeneration. Replication by other population-based studies is needed.

Average daily blood pressure, not office blood pressure, is associated with progression of cerebrovascular disease and cognitive decline in older people

BACKGROUND

High blood pressure (BP) is a risk factor for cerebrovascular disease, including stroke. Little is known about the importance of BP on the progression of microvascular disease of the brain, which has been associated with functional decline in mobility and cognition in older people.

METHODS AND RESULTS

This was a prospective cohort of subjects 75 to 89 years of age to determine relations among vascular risk factors, white matter hyperintensity volume, and functional status. Ninety-nine subjects were enrolled through the use of a balanced 3×3 matrix stratified by age and mobility performance, and 72 subjects completed all sets of baseline and follow-up studies at 2 years. Subjects were excluded if there were medications or systemic or neurological diseases that could compromise mobility. Ambulatory and clinic BP monitoring, magnetic resonance imaging, gait studies, and neuropsychological testing were performed at baseline and after 24 months. Brain classification into normal white matter and T2-hyperintense white matter hyperintensity volume was performed with semiautomated segmentation. Quantitative measures of mobility and cognitive function were obtained longitudinally. Increased ambulatory systolic BP, but not clinic systolic BP, from baseline to 24 month follow-up was associated with increased white matter hyperintensity volume over that same period, as well as measures of executive function/processing speed. Similar associations were observed for 24-hour BP, awake BP, and sleep BP but not for the surge between the sleep and awake time at the 24-month time point.

CONCLUSIONS

These data demonstrate for the first time the importance of 24-hour systolic BP in the progression of brain white matter hyperintensity volume burden associated with impairment of cognitive function in older people. The 24-hour systolic BP may be a potential target for intervention in the elderly to reduce vascular disease of the brain and impairment of function.

Markers of cholesterol metabolism in the brain show stronger associations with cerebrovascular disease than Alzheimer's disease

Cholesterol metabolism is believed to play a role in the development of Alzheimer's disease (AD). Oxysterol metabolites of cholesterol, 24S-hydroxycholesterol (24-OHC, a brain-derived oxysterol) and 27-hydroxycholesterol (27-OHC, a peripherally derived oxysterol) cross the blood brain barrier and have been associated with AD. We investigated whether oxysterols were associated with markers of cerebrovascular disease prior to the onset of cognitive impairment. Oxysterols were quantified in 105 participants (average age: 80 ± 4 years) from the Pittsburgh Cardiovascular Health Study Cognition Study who remained cognitively normal at blood draw in 2002, had MRI in 1992 and 1998, and annual cognitive assessment for incident AD and mild cognitive impairment made by consensus conference between 1998 and 2010. Higher plasma levels of 24-OHC were associated with age, gender, the presence of high grade white matter hyperintensities, and brain infarcts on prior MRI. Participants with higher plasma 24-OHC and a greater ratio of 24-OHC/27-OHC were also more likely to develop incident cognitive impairment over 8 years of follow-up. Higher levels of 24-OHC suggest increased cholesterol metabolism occurring in the brains of participants with cerebrovascular disease prior to the onset of cognitive impairment. Measurement of oxysterols may provide information about cholesterol metabolism and brain disease over the cognitive impairment process.

Risk factor profile for chronic kidney disease is similar to risk factor profile for small artery disease

BACKGROUND AND METHOD

We investigated whether chronic kidney disease detected by increased serum creatinine (S(Cr)) or urine albumin-to-creatinine ratio (U(ACR)) may reflect arteriosclerosis involving the kidneys. The sample consisted of 1585 members of sibships (804 non-Hispanic whites and 781 non-Hispanic blacks) in which at least two siblings had primary hypertension. We first evaluated the correlations of increased S(Cr) and U(ACR) with the presence of cerebral small vessel arteriosclerosis, which was determined by increased subcortical white matter hyperintensity (WMH) volume on brain magnetic resonance imaging; and with peripheral large vessel arteriosclerosis, which was determined by decreased ankle-brachial index (ABI). After age adjustment, increased S(Cr) and U(ACR) correlated with increased WMH volume (0.54 and 0.52, respectively) and with decreased ABI (0.50 and 0.54, respectively; all P < 0.001). We then used logistic regression to evaluate the dependency of each measure of disease on conventional risk factors for arteriosclerosis to assess whether the risk factors' effects were proportional across different measures of disease.

RESULTS

Age, race, sex, hypertension, diabetes, total cholesterol, and smoking made similar overall contributions to the prediction of each measure of disease, as judged by the model C-statistics, which varied in a narrow range from 0.84 to 0.85 (all P < 0.001). However, the relative contributions that the modifiable risk factors, including hypertension, diabetes, total cholesterol, and smoking made to prediction of increased S(Cr) and U(ACR) were disproportionate to their relative contributions to prediction of decreased ABI (P < 0.0001).

CONCLUSION

The findings support the view that chronic kidney disease detected by increased S(Cr) or U(ACR) primarily reflects small vessel arteriosclerosis involving the kidneys.

Progression of magnetic resonance imaging-defined brain vascular disease predicts vascular events in elderly: the Cardiovascular Health Study

BACKGROUND AND PURPOSE

To determine whether progression of MRI-defined vascular disease predicts subsequent vascular events in the elderly.

METHODS

The Cardiovascular Health Study, a longitudinal cohort study of vascular disease in the elderly, allows us to address this question because its participants had 2 MRI scans≈5 years apart and have been followed for ≈9 years since the follow-up scan for incident vascular events.

RESULTS

Both MRI-defined incident infarcts and worsened white matter grade were significantly associated with heart failure, stroke, and death, but not transient ischemic attacks, angina, or myocardial infarction. Strongest associations occurred when both incident infarcts and worsened white matter grade were present for heart failure (hazard ratio, 1.79; 95% confidence interval, 1.18-2.73), stroke (hazard ratio, 2.58; 95% confidence interval, 1.53-4.36), death (hazard ratio, 1.69; 95% confidence interval, 1.28-2.24), and cardiovascular death (hazard ratio, 1.97; 95% confidence interval, 1.24-3.14).

CONCLUSIONS

Progression of MRI-defined vascular disease identifies elderly people at increased risk for subsequent heart failure, stroke, and death. Whether aggressive risk factor management would reduce risk is unknown.