Vascular Risk Factor Profiles Differ Between Magnetic Resonance Imaging-Defined Subtypes of Younger-Onset Lacunar Stroke

Association between Life's Essential 8 and Cerebral Small Vessel Disease

BACKGROUND

Given that associations of Life's Essential 8 (LE8) and cerebral small vessel disease (CSVD) or its imaging markers were unclear, we examined relationship between them.

METHODS

The cross-sectional study included community residents from the PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events study. We calculated the total LE8 score, medical LE8 score and behavioural score, and categorised them into low (<60), moderate (60-79) or high (≥80) group. MRI markers included lacunes, white matter hyperintensities (WMH), enlarged perivascular spaces in basal ganglia (BG-EPVS) and cerebral microbleeds (CMB). In respect of, total CSVD score (0-4 points), WMH, lacunes or CMB were categorised as two grades, and BG-EPVS (N>10) was allocated one point. Based on modified total CSVD score (0-6 points), WMH or CMB was modified to three grades, and BG-EPVS (N>20) was allocated one point.

RESULTS

Among 3061 participants in this study, 1424 (46.5%) were male. Higher LE8 score was associated with lower total CSVD score (moderate vs low: cOR 0.78, 95% CI 0.63 to 0.96; high vs low: cOR 0.44, 95% CI 0.33 to 0.59), and the medical score was inversely related to the total CSVD score. Furthermore, the medical score was inversely related to odds of WMH (p<0.05), modified WMH (p<0.05), lacunes (p<0.05) or BG-EPVS (p<0.05), and the behavioural score were inversely related to the odds of lacunes and BG-EPVS.

CONCLUSIONS

Higher LE8 score which indicates better cardiovascular status was associated with lower burden of CSVD and its MRI markers. Longitudinal studies are needed to examine the causality.

Quantitative morphometric changes in vascular mild cognitive impairment patients: early diagnosis of dementia

Vascular mild cognitive impairment (VMCI) is an early and reversible stage of dementia. Volume differences in regional gray matter may reveal the development and prognosis of VMCI. This study selected 2 of the most common types of VMCI, namely, periventricular white matter hyperintensities (PWMH, n = 14) and strategic single infarctions (SSI, n = 10), and used the voxel-based morphometry method to quantify their morphological characteristics. Meanwhile, age- and sex-matched healthy volunteers were included (n = 16). All the participants were neuropsychologically tested to characterize their cognitive function and underwent whole-brain magnetic resonance imaging scanning. Our results showed that the volumes of the bilateral temporal lobes and bilateral frontal gray matter were obviously diminished in the PWMH group. The atrophy volume difference was 4,086 voxels in the left temporal lobe, 4,154 voxels in the right temporal lobe, 1,718 voxels in the left frontal lobe, and 1,141 voxels in the right frontal lobe (P ≤ 0.001). Moreover, the characteristics of the gray matter atrophy associated with the PWMH were more similar to those associated with Alzheimer's disease than SSI, which further revealed the susceptibility for escalation from PWMH to dementia. In conclusion, PWMH patients and SSI patients have different morphological characteristics, which explain the different prognoses of VMCI.

Implication of Cerebral Small-Vessel Disease on Perihematomal Edema Progress in Patients With Hypertensive Intracerebral Hemorrhage

BACKGROUND

Perihematomal edema (PHE) is an important determinant of outcome in spontaneous intracerebral hemorrhage (ICH) due to cerebral small vessel disease (CSVD). However, it is not known to date whether the severity of CSVD is associated with the extent of PHE progression in the acute phase.

PURPOSE

To investigate the association between the magnetic resonance imaging (MRI) marker of severe chronic-ischemia cerebral small vessel changes (sciSVC) and PHE growth or hematoma absorption among ICH patients with hypertension.

STUDY TYPE

Retrospective.

POPULATION

Three hundred and sixty-eight consecutive hypertensive ICH patients without surgical treatment.

FIELD STRENGTH/SEQUENCE

3 T; spin-echo echo-planar imaging-diffusion-weighted imaging (DWI); T2-weighted, fluid-attenuated inversion recovery (FLAIR), T2*-weighted gradient-recalled echo and T1-weighted.

ASSESSMENT

The hematoma and PHE volumes at 24 hours and 5 days after symptom onset were measured in 121 patients with spontaneous ICH who had been administered standard medical treatment. Patients were grouped into two categories: those with sciSVC and those without. The imaging marker of sciSVC was defined as white matter hyperintensities (WMHs) Fazekas 2-3 combined cavitating lacunes.

STATISTICAL TESTS

Univariable analyses, χ² test, Mann-Whitney U test, and multiple linear regression.

RESULTS

The presence of sciSVC (multiple lacunes and confluent WMH) had a significant negative influence on PHE progress (Beta = -5.3 mL, 95% CI = -10.3 mL to -0.3 mL), and hematoma absorption (Beta = -3.2 mL, 95% CI = -5.9 mL to -0.4 mL) compared to that observed in the absence of sciSVC, as determined by multivariate linear regression analysis.

DATA CONCLUSIONS

The presence of sciSVC (multiple lacunes and confluent WMH) negatively influenced hematoma absorption and PHE progress in ICH patients.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 3.

Correlation between silent lacunar strokes and retinopathies seen on fundus among patients hospitalized for lacunar strokes: An observational study at the neurology department of Befelatanana University Hospital

Retinal and cerebral arterioles have similar characteristics. Silent infarcts are associated with a risk of incident lacunar stroke and dementia. The objective of our study was to determine the correlation between silent lacunar strokes and retinopathy in patients hospitalized in our department for lacunar strokes. This is an observational, retrospective study, from July 2018 to December 2019, of patients diagnosed with lacunar stroke at the neurology department of Befelatanana Hospital, Antananarivo. Stroke was diagnosed with brain CT scan and retinopathy was classified according to fundus examination. The correlation between the presence of silent lacunar stroke and different types and stages of retinopathy was studied. Silent lacunar lesions were discovered on imaging in 70.59% of patients with lacunar strokes. All patients with symptomatic lacunar stroke, with or without associated silent lacunar lesions, were hypertensives. No statistical difference was found between patients with or without associated silent lacunar lesions according to age and gender. Among patients with silent lacunar lesions, dysexecutive syndrome was more prevalent as compared to patients without silent lesions (52.63% vs. 47.36%, P=0.03). Arteriolopathy was more prevalent in patients with silent lacunar lesions (85.71% vs. 14.28%, P=0.047). Silent lacunar lesions were unique in 72% of cases (P=0.022). The presence of stage II hypertensive retinopathy was significantly correlated with the presence of silent lacunar lesions (OR 5.20 [1.02-267] [1.02-26.47], P=0.018). Upon discovery of stage II hypertensive retinopathy on fundus examination, brain imaging should be performed for silent lacunar stroke screening to optimize hypertension management. This management is expected to prevent the incidence of lacunar stroke and vascular dementia.

Interactions Between Kidney Function and Cerebrovascular Disease: Vessel Pathology That Fires Together Wires Together

The kidney and the brain, as high-flow end organs relying on autoregulatory mechanisms, have unique anatomic and physiological hemodynamic properties. Similarly, the two organs share a common pattern of microvascular dysfunction as a result of aging and exposure to vascular risk factors (e.g., hypertension, diabetes and smoking) and therefore progress in parallel into a systemic condition known as small vessel disease (SVD). Many epidemiological studies have shown that even mild renal dysfunction is robustly associated with acute and chronic forms of cerebrovascular disease. Beyond ischemic SVD, kidney impairment increases the risk of acute cerebrovascular events related to different underlying pathologies, notably large artery stroke and intracerebral hemorrhage. Other chronic cerebral manifestations of SVD are variably associated with kidney disease. Observational data have suggested the hypothesis that kidney function influences cerebrovascular disease independently and adjunctively to the effect of known vascular risk factors, which affect both renal and cerebral microvasculature. In addition to confirming this independent association, recent large-scale human genetic studies have contributed to disentangling potentially causal associations from shared genetic predisposition and resolving the uncertainty around the direction of causality between kidney and cerebrovascular disease. Accelerated atherosclerosis, impaired cerebral autoregulation, remodeling of the cerebral vasculature, chronic inflammation and endothelial dysfunction can be proposed to explain the additive mechanisms through which renal dysfunction leads to cerebral SVD and other cerebrovascular events. Genetic epidemiology also can help identify new pathological pathways which wire kidney dysfunction and cerebral vascular pathology together. The need for identifying additional pathological mechanisms underlying kidney and cerebrovascular disease is attested to by the limited effect of current therapeutic options in preventing cerebrovascular disease in patients with kidney impairment.

Accurate Prediction of Stroke for Hypertensive Patients Based on Medical Big Data and Machine Learning Algorithms: Retrospective Study

Background

Stroke risk assessment is an important means of primary prevention, but the applicability of existing stroke risk assessment scales in the Chinese population has always been controversial. A prospective study is a common method of medical research, but it is time-consuming and labor-intensive. Medical big data has been demonstrated to promote disease risk factor discovery and prognosis, attracting broad research interest.

Objective

We aimed to establish a high-precision stroke risk prediction model for hypertensive patients based on historical electronic medical record data and machine learning algorithms.

Methods

Based on the Shenzhen Health Information Big Data Platform, a total of 57,671 patients were screened from 250,788 registered patients with hypertension, of whom 9421 had stroke onset during the 3-year follow-up. In addition to baseline characteristics and historical symptoms, we constructed some trend characteristics from multitemporal medical records. Stratified sampling according to gender ratio and age stratification was implemented to balance the positive and negative cases, and the final 19,953 samples were randomly divided into a training set and test set according to a ratio of 7:3. We used 4 machine learning algorithms for modeling, and the risk prediction performance was compared with the traditional risk scales. We also analyzed the nonlinear effect of continuous characteristics on stroke onset.

Results

The tree-based integration algorithm extreme gradient boosting achieved the optimal performance with an area under the receiver operating characteristic curve of 0.9220, surpassing the other 3 traditional machine learning algorithms. Compared with 2 traditional risk scales, the Framingham stroke risk profiles and the Chinese Multiprovincial Cohort Study, our proposed model achieved better performance on the independent validation set, and the area under the receiver operating characteristic value increased by 0.17. Further nonlinear effect analysis revealed the importance of multitemporal trend characteristics in stroke risk prediction, which will benefit the standardized management of hypertensive patients.

Conclusions

A high-precision 3-year stroke risk prediction model for hypertensive patients was established, and the model's performance was verified by comparing it with the traditional risk scales. Multitemporal trend characteristics played an important role in stroke onset, and thus the model could be deployed to electronic health record systems to assist in more pervasive, preemptive stroke risk screening, enabling higher efficiency of early disease prevention and intervention.

Differential Characteristics of Ischemic and Hemorrhagic Stroke in Patients with Cerebral Small Vessel Disease

Background

Small vessel disease (SVD) is the underlying anatomical substrate for both lacunar infarction and subcortical hemorrhage.

Aim

To assess predictive factors of ischemic or hemorrhagic stroke in patients with cerebral SVD.

Materials and Methods

Prospective hospital-based stroke registry ("The Sagrat Cor Hospital of Barcelona Stroke Registry") in an acute-care teaching hospital in Barcelona, Spain. From 4597 acute stroke patients included in the stroke registry over a 24-year period, 440 cases of lacunar stroke and 210 of subcortical intracerebral hemorrhage were selected. Demographics, clinical characteristics, risk factors, and early outcome were compared. Predictors of lacuna versus subcortical hemorrhage were assessed by multivariate analyses.

Results

In a logistic regression model based on demographics, risk factors, clinical features and outcome, dyslipidemia (odds ratio [OR] 2.06 (95% confidence interval (CI) 1.17-3.62) and diabetes (OR 1.97, 95% CI 1.19-3.26) were independent risk factors for lacunar infarction. Anticoagulation therapy (OR 0.05, 95% CI 0.01-0.28), sudden onset (OR 0.51, 95% CI 0.33-0.78), motor symptoms (OR 0.44, 95% CI 0.26-0.76), headache (OR 0.23, 95% CI 0.12-0.41), altered consciousness (OR 0.10, 95% CI 0.05-0.21), respiratory complications (OR 0.19, 95% CI 0.08-0.46), and in-hospital death (OR 0.08, 95% CI 0.02-0.36) were predictors of subcortical hemorrhage.

Conclusion

Identification of differential clinical and prognostic profile between ischemic and hemorrhagic consequences of underlying cerebral SVD is useful for risk stratification in the current process pursuing precision medicine.

Genetic basis of lacunar stroke: a pooled analysis of individual patient data and genome-wide association studies

BACKGROUND

The genetic basis of lacunar stroke is poorly understood, with a single locus on 16q24 identified to date. We sought to identify novel associations and provide mechanistic insights into the disease.

METHODS

We did a pooled analysis of data from newly recruited patients with an MRI-confirmed diagnosis of lacunar stroke and existing genome-wide association studies (GWAS). Patients were recruited from hospitals in the UK as part of the UK DNA Lacunar Stroke studies 1 and 2 and from collaborators within the International Stroke Genetics Consortium. Cases and controls were stratified by ancestry and two meta-analyses were done: a European ancestry analysis, and a transethnic analysis that included all ancestry groups. We also did a multi-trait analysis of GWAS, in a joint analysis with a study of cerebral white matter hyperintensities (an aetiologically related radiological trait), to find additional genetic associations. We did a transcriptome-wide association study (TWAS) to detect genes for which expression is associated with lacunar stroke; identified significantly enriched pathways using multi-marker analysis of genomic annotation; and evaluated cardiovascular risk factors causally associated with the disease using mendelian randomisation.

FINDINGS

Our meta-analysis comprised studies from Europe, the USA, and Australia, including 7338 cases and 254 798 controls, of which 2987 cases (matched with 29 540 controls) were confirmed using MRI. Five loci (ICA1L-WDR12-CARF-NBEAL1, ULK4, SPI1-SLC39A13-PSMC3-RAPSN, ZCCHC14, ZBTB14-EPB41L3) were found to be associated with lacunar stroke in the European or transethnic meta-analyses. A further seven loci (SLC25A44-PMF1-BGLAP, LOX-ZNF474-LOC100505841, FOXF2-FOXQ1, VTA1-GPR126, SH3PXD2A, HTRA1-ARMS2, COL4A2) were found to be associated in the multi-trait analysis with cerebral white matter hyperintensities (n=42 310). Two of the identified loci contain genes (COL4A2 and HTRA1) that are involved in monogenic lacunar stroke. The TWAS identified associations between the expression of six genes (SCL25A44, ULK4, CARF, FAM117B, ICA1L, NBEAL1) and lacunar stroke. Pathway analyses implicated disruption of the extracellular matrix, phosphatidylinositol 5 phosphate binding, and roundabout binding (false discovery rate <0·05). Mendelian randomisation analyses identified positive associations of elevated blood pressure, history of smoking, and type 2 diabetes with lacunar stroke.

INTERPRETATION

Lacunar stroke has a substantial heritable component, with 12 loci now identified that could represent future treatment targets. These loci provide insights into lacunar stroke pathogenesis, highlighting disruption of the vascular extracellular matrix (COL4A2, LOX, SH3PXD2A, GPR126, HTRA1), pericyte differentiation (FOXF2, GPR126), TGF-β signalling (HTRA1), and myelination (ULK4, GPR126) in disease risk.

FUNDING

British Heart Foundation.

The Relationship Between Glucose Control and Cognitive Function in People With Diabetes After a Lacunar Stroke

CONTEXT

Lacunar strokes and diabetes are risk factors for cognitive dysfunction. Elucidating modifiable risk factors for cognitive dysfunction has great public health implications. One factor may be glycemic status, as measured by glycated hemoglobin (A1c).

OBJECTIVE

The aim of this study was to assess the relationship between A1c and cognitive function in lacunar stroke patients with diabetes.

METHODS

The effect of baseline and follow-up A1c on the baseline and the change in Cognitive Assessment Screening Instrument (CASI) score over time among participants with a median of 2 cognitive assessments (range, 1-5) was examined in 942 individuals with diabetes and a lacunar stroke who participated in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial (ClinicalTrials.gov No. NCT00059306).

RESULTS

Every 1% higher baseline A1c was associated with a 0.06 lower standardized CASI z score (95% CI, -0.101 to -0.018). Higher baseline A1c values were associated with lower CASI z scores over time (P for interaction = .037). A 1% increase in A1c over time corresponded with a CASI score decrease of 0.021 (95% CI, -0.0043 to -0.038) during follow-up. All these remained statistically significant after adjustment for age, sex, education, race, depression, hypertension, hyperlipidemia, body mass index, cardiovascular disease, obstructive sleep apnea, diabetic retinopathy, nephropathy insulin use, and white-matter abnormalities.

CONCLUSION

This analysis of lacunar stroke patients with diabetes demonstrates a relationship between A1c and change in cognitive scores over time. Intervention studies are needed to delineate whether better glucose control could slow the rate of cognitive decline in this high-risk population.

Association between admission blood fibrinogen-to-albumin ratio and clinical outcomes after acute lacunar stroke

Aim: We aimed to investigate the influence of admission fibrinogen-to-albumin ratio (FAR) on 3-month outcomes after acute lacunar stroke. Materials & methods: Consecutive patients with acute lacunar stroke were included and classified into two groups according to an optimized FAR cut-off value determined by receiver operating characteristic curve analysis. Results: Compared with those with low FAR (<0.077), patients from the high FAR group (≥0.077) had significantly higher risk for 3-month disability and the composite outcome of death/disability. After logistic regression adjustment, high FAR was still significantly associated with 3-month disability and death/disability. Conclusion: FAR ≥0.077 on admission might be an independent predictor of disability and death/disability at 3 months after lacunar stroke, which needs to be verified in future studies.

Relevance of cerebral small vessel disease load scores in first-ever lacunar infarction

AIM

To reveal the correlation between total cerebrovascular disease load and primary lacunar infarction.

BACKGROUND

Cerebral small vessel disease (CSVD) is the lack of specific clinical manifestations, whose clinical diagnoses are highly dependent on neuroimaging results. Total CSVD load scores may be more suitable for the assessment of overall brain function damage caused by CSVD. Little is known about whether the association between imaging markers of CSVD and CSVD total load scores at the time of first-ever lacunar infarction (LI).

METHODS

clinical data of 396 patients hospitalised from September 2016 to May 2018 due to a first-ever LI (case group), along with patients diagnosed with CSVD based on imaging alone and those with no abnormalities (control group) based on magnetic resonance imaging (MRI). Binary logistic regression and multiple ordered logistic regression were used to analyse the characteristics of imaging markers of CSVD in patients with first-ever LI, including different total score burden and distribution, and the relationship between different markers.

RESULTS

In 396 patients, smoking, cholesterol level and total small vessel disease (SVD) score were all significantly associated with the first-ever LI. There were more LI, cerebral microbleeds (CMB), white matter hyperintensities (WMH), and moderate to severe enlarged perivascular spaces (EPVS) in the first-ever LI group, relative to controls (p < 0.01). The Fazekas scores for periventricular WMH, deep WMH, and total Fazekas score were all significantly higher in patients with first-ever LI relative to those with no cerebral abnormalities (p < 0.01). An analysis of various imaging markers of CSVD revealed a significant correlation between the presence and degree of any marker and the severity of other markers, even after adjusting for the presence of other markers (p < 0.05).

CONCLUSIONS

The first-ever LI group exhibited higher total CSVD score loads, a greater number of lacunae, CMB, severe WMH and moderate to severe EPVS. Smoking is an independent risk factor in patients with first-ever LI.

Relation between left atrial structure and lacunar infarction in patients with hypertension

A lacunar infarction (LACI) can cause damage to the surrounding brain tissue and place an individual at greater risk for future major stroke. LACI is associated with hypertension and hypertension is associated with left atrial enlargement. It is important to identify a high-risk patient who is more vulnerable to suffering a LACI in hypertensive group. So, we studied whether left atrium size is an independent risk predictor for LACI in hypertensive patients. We performed cross-sectional analysis of 365 patients with hypertension at Shanghai Ninth People's Hospital from January 2016 to January 2017. The results showed that left atrial diameter(LAD), left atrial volume (LAV) and the ratio of left atrial diameter to left ventricular diameter (LAD/LVD) were significantly associated with LACI in hypertensive patients. Based on the ROC curve analysis, the area under the ROC curve (AUC) of LAV used to predict LACI was 0.737 (95% CI: 0.686 - 0.788), and the AUC of LAD/LVD was 0.784 (95% CI: 0.737 - 0.830). The optimal cut-off value for LAV was 30.14, and the sensitivity and specificity were 72% and 63%, respectively. The optimal cut-off value for LAD/LVD was 0.757, and the sensitivity and specificity were 77% and 70%, respectively. LAV or LAD/LVD played an important role in LACI with hypertension and could be an independent risk factor in hypertensive patients.

Higher tea consumption is associated with decreased risk of small vessel stroke

BACKGROUND & AIM

Observational studies have reported that tea consumption is associated with risk of stroke. However, this observed association is inconsistent, and whether this observed association is due to confounding factors or reverse causation remains unclear. Thus, we applied a two-sample mendelian randomization (MR) approach to determine whether genetically predicted tea consumption is causally associated with risk of stroke, ischemic stroke (IS), and IS subtypes.

METHODS

UK Biobank available data (349,376 samples of European ancestry) was used to identify single nucleotide polymorphisms associated with tea consumption (cups/day). The summary statistics for stroke, IS, and IS subtypes were obtained from the MEGASTROKE consortium with 40,585 stroke cases and 406,111 controls.

RESULTS

We found that genetically predicted an extra daily cup of tea consumption was casually associated with a reduced risk of small vessel stroke (odds ratio (OR), 0.79; 95% confidence interval (CI), 0.69-0.91; P = 0.001), but not with cardioembolic stroke (OR, 0.97; 95% CI, 0.86-1.09; P = 0.582), large artery stroke (OR, 0.95; 95% CI, 0.82-1.10; P = 0.506), stroke (OR, 1.00; 95% CI, 0.95-1.06; P = 0.889) or IS (OR, 0.95; 95% CI, 0.89-1.01; P = 0.083).

CONCLUSIONS

Our study provided evidence that genetically predicted an extra daily cup of tea consumption is causally associated with a reduced risk of small vessel stroke.

Stroke in the patient with diabetes (part 1) - Epidemiology, etiology, therapy and prognosis

There is a higher incidence of stroke in both the type 2 diabetic and the non-diabetic insulin resistant patient which is accompanied by higher morbidity and mortality. The increase in the frequency of stroke is due to an increase in cerebral infarction, mainly lacunar infarcts, with the incidence of cerebral hemorrhage being less frequent. The major risk factors for stroke in the type 2 diabetic patient are age, hypertension, the number of features of the Metabolic Syndrome, the presence of diabetic nephropathy in both the type 1 and type 2 patient, the presence of peripheral and coronary artery disease and especially the presence of atrial fibrillation. Hyperglycemia is associated with a poor outcome from stroke but is not causative.

Major depression and small vessel stroke: a Mendelian randomization analysis

BACKGROUND AND PURPOSE

Although observational studies have reported a positive association between depression and ischemic stroke, causality remains inconclusive. We aimed to assess the causal relationship of major depressive disorder (MDD) with ischemic stroke, especially with the small vessel stroke (SVS) subtype.

METHODS

We used 72 independent single-nucleotide polymorphisms associated with MDD in a genome-wide association study (GWAS) from the Psychiatric Genetics Consortium as instrumental variables. The corresponding data for ischemic stroke and its subtypes of European ancestry were available from the MEGASTROKE consortium of 34,217 ischemic stroke cases and 406,111 controls. Primary Mendelian randomization estimates were calculated with inverse-variance weighted method, and several alternate methods and multiple sensitivity analyses were also performed.

RESULTS

We found that genetic predisposition to higher risk of MDD was associated with higher risk of SVS, with an odds ratio of 1.33 (95% confidence interval, 1.08-1.65; p = 0.009) per log-odds increment in MDD risk, but not with large artery stroke (OR, 1.08; 95% CI 0.83-1.41; p = 0.559), cardioembolic stroke (OR, 0.98; 95% CI 0.80-1.20; p = 0.833), or all ischemic stroke (OR, 1.03; 95% CI 0.92-1.15; p = 0.633). The association of MDD with SVS was overall robust to sensitivity analyses.

CONCLUSIONS

We provided evidence for a possible causal effect of MDD on increased risk of SVS. Future researches are required to investigate whether rational intervention on depression may help to reduce societal burden of SVS.

The effect of antidementia drugs on mortality in patients with Alzheimer's disease

INTRODUCTION

Alzheimer's disease is associated with a higher mortality rate after the diagnosis. We hypothesized that patients with Alzheimer's disease who received antidementia drugs may have a lower mortality rate than those without such treatment.

METHODS

Patients with newly diagnosed Alzheimer's disease aged ⩾65 years during 2001-2006 were identified in the National Health Institute Research Database, Taiwan. We included patients with Alzheimer's disease who received antidementia drugs as the exposure group (ADD group), and compared them with a non-exposure group who did not receive any antidementia drugs (non-ADD group) matched for age at the index date, gender and Charlson Comorbidity Index score before the index date. All-cause mortality rates and Charlson Comorbidity Index scores at one and two years after the index date were compared between the ADD and non-ADD groups.

RESULTS

There were 529 patients in non-ADD group and 529 in the ADD group. The mortality rate was significantly lower in the ADD group compared with the non-ADD group (42% versus 58.6%; p<0.0001).

CONCLUSION

Our results suggest that antidementia drugs may have a protective effect against mortality in patients with Alzheimer's disease.

Insulin Resistance Is a Risk Factor for Overall Cerebral Small Vessel Disease Burden in Old Nondiabetic Healthy Adult Population

Background and Purpose: This study aimed to investigate the association between insulin resistance (IR) and the overall cerebral small vessel disease (CSVD) burden.

Methods: We recruited elderly, nondiabetic, healthy subjects prospectively. The overall effect of CSVD on the brain was described by a validated CSVD score. The homeostasis model assessment–estimated insulin resistance index (HOMA-IR) was used for IR estimation, and HOMA-IR ≥2.80 was defined as IR. We evaluated the association between IR and the increasing severity of CSVD score by ordinal regression models adjusting for demographics and cardiovascular risk factors.

Results: A total of 156 healthy participants were recruited. The mean age was older in the IR group than in the non-IR group (70.03 vs. 67.45, p = 0.04), and the prevalence of hypertension was significantly higher in the IR group than in the non-IR group (82.35% vs. 53.28%, p < 0.01). In ordinal regression analysis, IR was positively associated with increasing severity of the total CSVD score (adjusted odds ratio, 3.74; 95% confidence interval, 1.63–5.08; p < 0.01) after adjusting traditional risk factors. Furthermore, HOMA-IR levels showed a positive dose-dependent correlation with the total CSVD score (p < 0.01, p for trend <0.01).

Conclusions: IR is independently associated with increasing severity of the overall CSVD burden, independent of other clinical risk factors in an elderly, nondiabetic, healthy population. Furthermore, HOMA-IR level is correlated with the CSVD burden in a dose-dependent manner.

Assessment of the Role of Carotid Atherosclerosis in the Association Between Major Cardiovascular Risk Factors and Ischemic Stroke Subtypes

IMPORTANCE

A better understanding of the role of atherosclerosis in the development of ischemic stroke subtypes could help to improve strategies for prevention of stroke worldwide.

OBJECTIVE

To assess the role of carotid atherosclerosis in the association between major cardiovascular risk factors and ischemic stroke subtypes.

DESIGN, SETTING, AND PARTICIPANTS

The prospective China Kadoorie Biobank cohort study was conducted in the general population of 5 urban and 5 rural areas in China, with a baseline survey obtained between June 2004 and July 2008. A random sample of 23 973 participants with no history of cardiovascular disease at enrollment who had carotid artery ultrasonographic measurements recorded at a resurvey from September 2013 to June 2014 were included. Data analysis was performed from July 1, 2016, to April 10, 2019.

EXPOSURES

Major cardiovascular risk factors (ie, blood pressure [BP], blood lipid levels, smoking, and diabetes).

MAIN OUTCOMES AND MEASURES

Carotid ultrasonographic measures of plaque burden (derived from number and maximum size of carotid artery plaques at resurvey) and first ischemic stroke during follow-up (n = 952), with subtyping (data release, August 2018) as lacunar (n = 263), probable large artery (n = 193), probable cardioembolic (n = 66), or unconfirmed (n = 430). Associations between cardiovascular risk factors, carotid plaque burden, and ischemic stroke subtypes were adjusted for age, sex, and geographic area.

RESULTS

The 23 973 participants in the study had a mean (SD) age of 50.6 (10.0) years, and 14 833 (61.9%) were women. Systolic BP had a stronger association (odds ratio [OR] per SD, 1.51; 95% CI, 1.42-1.61) than plaque burden (OR per SD, 1.34; 95% CI, 1.26-1.44) with ischemic stroke, and the associations of systolic BP with each subtype of ischemic stroke were modestly attenuated by adjustment for plaque burden. After adjustment for BP, plaque burden had a stronger association with probable large artery stroke (OR, 1.43; 95% CI, 1.24-1.63) than with lacunar stroke (OR, 1.25; 95% CI, 1.10-1.43) but was not associated with probable cardioembolic stroke (OR, 1.06; 95% CI, 0.83-1.36).

CONCLUSIONS AND RELEVANCE

Although BP was an important risk factor for all ischemic stroke subtypes, carotid atherosclerosis was an important risk factor only for large artery and lacunar strokes, suggesting that drug treatments targeting atherosclerosis may reduce the risk of stroke subtypes to different extents.

Homocysteine and small vessel stroke: A mendelian randomization analysis

Objective

Trials of B vitamin therapy to lower blood total homocysteine (tHcy) levels for prevention of stroke are inconclusive. Secondary analyses of trial data and epidemiological studies suggest that tHcy levels may be particularly associated with small vessel stroke (SVS). We assessed whether circulating tHcy and B vitamin levels are selectively associated with SVS, but not other stroke subtypes, using Mendelian randomization.

Methods

We used summary statistics data for single‐nucleotide polymorphisms (SNPs) associated with tHcy (n = 18), folate (n = 3), vitamin B₆ (n = 1), and vitamin B₁₂ (n = 14) levels, and the corresponding data for stroke from the MEGASTROKE consortium (n = 16,952 subtyped ischemic stroke cases and 404,630 noncases).

Results

Genetically predicted tHcy was associated with SVS, with an odds ratio of 1.34 (95% confidence interval [CI], 1.13–1.58; p = 6.7 × 10^–4) per 1 standard deviation (SD) increase in genetically predicted tHcy levels, but was not associated with large artery or cardioembolic stroke. The association was mainly driven by SNPs at or near the MTHFR and MUT genes. The odds ratios of SVS per 1 SD increase in genetically predicted folate and vitamin B₆ levels were 0.49 (95% CI, 0.34–0.71; p = 1.3 × 10^–4) and 0.70 (95% CI, 0.52–0.94; p = 0.02), respectively. Genetically higher vitamin B₁₂ levels were not associated with any stroke subtype.

Interpretation

These findings suggest that any effect of homocysteine‐lowering treatment in preventing stroke will be confined to the SVS subtype. Whether genetic variants at or near the MTHFR and MUT genes influence SVS risk through pathways other than homocysteine levels and downstream effects require further investigation. Ann Neurol 2019;85:495–501

Emerging insights from the genetics of cerebral small-vessel disease

Cerebral small-vessel disease (cSVD) is a common cause of stroke, functional decline, vascular cognitive impairment, and dementia. Pathological processes in the brain's microcirculation are tightly interwoven with pathology in the brain parenchyma, and this interaction has been conceptualized as the neurovascular unit (NVU). Despite intensive research efforts to decipher the NVU's structure and function to date, molecular mechanisms underlying cSVD remain poorly understood, which hampers the development of cSVD-specific therapies. Important steps forward in understanding the disease mechanisms underlying cSVD have been made using genetic approaches in studies of both monogenic and sporadic SVD. We provide an overview of the NVU's structure and function, the implications for cSVD, and the underlying molecular mechanisms of dysfunction that have emerged from recent genetic studies of both monogenic and sporadic diseases of the small cerebral vasculature.

White-Matter Hyperintensities and Lacunar Infarcts Are Associated with an Increased Risk of Alzheimer's Disease in the Elderly in China

Background and Purpose

This study investigated the contribution of white-matter hyperintensities (WMH) and lacunar infarcts (LI) to the risk of Alzheimer's disease (AD) in an elderly cohort in China.

Methods

Older adults who were initially cognitively normal were examined with MRI at baseline, and followed for 5 years. WMH were classified as mild, moderate, or severe, and LI were classified into a few LI (1 to 3) or many LI (≥4). Cognitive function was assessed using the Mini Mental State Examination and the Activities of Daily Living scale.

Results

Among the 2,626 subjects, 357 developed AD by the end of the 5-year follow-up period. After adjusting for age and other potential confounders, having only WMH, having only LI, and having both WMH and LI were associated with an increased risk of developing AD compared with having neither WMH nor LI. Moderate and severe WMH were associated with an increased risk of developing AD compared with no WMH. Furthermore, patients with many LI had an increased risk of developing AD compared with no LI.

Conclusions

Having moderate or severe WMH and many LI were associated with an increased risk of developing AD, with this being particularly striking when both WMH and LI were present.

Cerebral small vessel disease: neuroimaging markers and clinical implication

Cerebral small vessel disease (CSVD) is a broad category of cerebrovascular diseases which primarily affect the perforating arterioles, capillaries and venules with multiple distinct etiologies. In spite of distinctive pathogenesis, CSVD shares similar neuroimaging markers, including recent small subcortical infarct, lacune of presumed vascular origin, white matter hyperintensity of presumed vascular origin, perivascular space and cerebral microbleeds. The radiological features of neuroimaging markers are indicative for etiological analysis. Furthermore, in sporadic arteriosclerotic pathogenesis associated CSVD, the total CSVD burden is a significant predictor for stroke events, global cognitive impairment, psychiatric disorders and later life quality. This review aims to summarize the radiological characteristics as well as the clinical implication of CSVD markers and neuroimaging interpretation for CSVD symptomatology.

Hypertension-Induced Cerebral Small Vessel Disease Leading to Cognitive Impairment

Objective:

Alzheimer's disease and vascular dementia are responsible for more than 80% of dementia cases. These two conditions share common risk factors including hypertension. Cerebral small vessel disease (CSVD) is strongly associated with both hypertension and cognitive impairment. In this review, we identify the pathophysiological changes in CSVD that are caused by hypertension and further explore the relationship between CSVD and cognitive impairment.

Data Sources:

We searched and scanned the PubMed database for recently published literatures up to December 2017. We used the keywords of “hypertension”, “cerebral small vessel disease”, “white matter lesions”, “enlarged perivascular spaces”, “lacunar infarcts”, “cerebral microbleeds”, and “cognitive impairment” in the database of PubMed.

Study Selection:

Articles were obtained and reviewed to analyze the hypertension-induced pathophysiological changes that occur in CSVD and the correlation between CSVD and cognitive impairment.

Results:

In recent years, studies have demonstrated that hypertension-related changes (e.g., small vascular lesions, inflammatory reactions, hypoperfusion, oxidative stress, damage to autoregulatory processes and the blood-brain barrier, and cerebral amyloid angiopathy) can occur over time in cerebral small vessels, potentially leading to lower cognitive function when blood pressure (BP) control is poor or lacking. Both isolated and co-occurrent CSVD can lead to cognitive deterioration, and this effect may be attributable to a dysfunction in either the cholinergic system or the functionality of cortical and subcortical tracts.

Conclusions:

We explore the currently available evidence about the hypertensive vasculopathy and inflammatory changes that occur in CSVD. Both are vital prognostic indicators of the development of cognitive impairment. Future studies should be performed to validate the relationship between BP levels and CSVD progression and between the numbers, volumes, and anatomical locations of CSVD and cognitive impairment.