Cerebral White Matter Hypoperfusion Increases with Small-Vessel Disease Burden. Data From the Third International Stroke Trial

The neurovascular unit and its correlation with cognitive performance in patients with cerebral small vessel disease: a canonical correlation analysis approach

Growing evidence indicates an important role of neurovascular unit (NVU) dysfunction in the pathophysiology of cerebral small vessel disease (cSVD). Individually measurable functions of the NVU have been correlated with cognitive function, but a combined analysis is lacking. We aimed to perform a unified analysis of NVU function and its relation with cognitive performance. The relationship between NVU function in the white matter and cognitive performance (both latent variables composed of multiple measurable variables) was investigated in 73 patients with cSVD (mean age 70 ± 10 years, 41% women) using canonical correlation analysis. MRI-based NVU function measures included (1) the intravoxel incoherent motion derived perfusion volume fraction (f) and microvascular diffusivity (D*), reflecting cerebral microvascular flow; (2) the IVIM derived intermediate volume fraction (fint), indicative of the perivascular clearance system; and (3) the dynamic contrast-enhanced MRI derived blood-brain barrier (BBB) leakage rate (Ki) and leakage volume fraction (VL), reflecting BBB integrity. Cognitive performance was composed of 13 cognitive test scores. Canonical correlation analysis revealed a strong correlation between the latent variables NVU function and cognitive performance (r 0.73; p = 0.02). For the NVU, the dominating variables were D*, fint, and Ki. Cognitive performance was driven by multiple cognitive tests comprising different cognitive domains. The functionality of the NVU is correlated with cognitive performance in cSVD. Instead of focusing on individual pathophysiological mechanisms, future studies should target NVU dysfunction as a whole to acquire a coherent understanding of the complex disease mechanisms that occur in the NVU in cSVD.Trial registration: NTR3786 (Dutch Trial Register).

Collagen IV deficiency causes hypertrophic remodeling and endothelium-dependent hyperpolarization in small vessel disease with intracerebral hemorrhage

BACKGROUND

Genetic variants in COL4A1 and COL4A2 (encoding collagen IV alpha chain 1/2) occur in genetic and sporadic forms of cerebral small vessel disease (CSVD), a leading cause of stroke, dementia and intracerebral haemorrhage (ICH). However, the molecular mechanisms of CSVD with ICH and COL4A1/COL4A2 variants remain obscure.

METHODS

Vascular function and molecular investigations in mice with a Col4a1 missense mutation and heterozygous Col4a2 knock-out mice were combined with analysis of human brain endothelial cells harboring COL4A1/COL4A2 mutations, and brain tissue of patients with sporadic CSVD with ICH.

FINDINGS

Col4a1 missense mutations cause early-onset CSVD independent of hypertension, with enhanced vasodilation of small arteries due to endothelial dysfunction, vascular wall thickening and reduced stiffness. Mechanistically, the early-onset dysregulated endothelium-dependent hyperpolarization (EDH) is due to reduced collagen IV levels with elevated activity and levels of endothelial Ca2+-sensitive K+ channels. This results in vasodilation via the Na/K pump in vascular smooth muscle cells. Our data support this endothelial dysfunction preceding development of CSVD-associated ICH is due to increased cytoplasmic Ca2+ levels in endothelial cells. Moreover, cerebral blood vessels of patients with sporadic CSVD show genotype-dependent mechanisms with wall thickening and lower collagen IV levels in those harboring common non-coding COL4A1/COL4A2 risk alleles.

INTERPRETATION

COL4A1/COL4A2 variants act in genetic and sporadic CSVD with ICH via dysregulated EDH, and altered vascular wall thickness and biomechanics due to lower collagen IV levels and/or mutant collagen IV secretion. These data highlight EDH and collagen IV levels as potential treatment targets.

FUNDING

MRC, Wellcome Trust, BHF.

Cerebral blood flow and cognition after 3 months tadalafil treatment in small vessel disease (ETLAS-2): study protocol for a randomized controlled trial

BACKGROUND

Targeted treatment is highly warranted for cerebral small vessel disease, a causal factor of one in four strokes and a major contributor to vascular dementia. Patients with cerebral small vessel disease have impaired cerebral blood flow and vessel reactivity. Tadalafil is a specific phosphodiesterase 5 inhibitor shown to improve vascular reactivity in the brain.

METHODS

The ETLAS-2 trial is a phase 2 double-blind, randomized placebo-controlled, parallel trial with the feasibility of tadalafil as the primary outcome. The trial aims to include 100 patients with small vessel occlusion stroke or transitory ischemic attacks and signs of cerebral small vessel disease more than 6 months before administration of study medication. Patients are treated for 3 months with tadalafil 20 mg or placebo daily and undergo magnetic resonance imaging (MRI) to evaluate changes in small vessel disease according to the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE) criteria as well as cerebral blood flow, cerebrovascular reactivity, and neurovascular coupling in a functional MRI sub-study. The investigation includes comprehensive cognitive testing using paper-pencil tests and Cambridge Neuropsychological Test Automated Battery (CANTAB) tests in a cognitive sub-study.

DISCUSSION

The ETLAS-2 trial tests the feasibility of long-term treatment with tadalafil and explores vascular and cognitive effects in cerebral small vessel disease in trial sub-studies. The study aims to propose a new treatment target and improve the understanding of small vessel disease. Currently, 64 patients have been included and the trial is estimated to be completed in the year 2024.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT05173896. Registered on 30 December 2021.

Factors associated with cognitive impairment before intracerebral haemorrhage: community-based neuropathological study

Little is known about whether clinical, radiological or neuropathological features are associated with cognitive impairment before intracerebral haemorrhage. We conducted a community-based cohort study of 125 adults with intracerebral haemorrhage (lobar n = 71, non-lobar n = 54) with consent to brain autopsy. We compared small vessel disease biomarkers on diagnostic CT head and neuropathological findings including neurofibrillary tangles and amyloid plaques in adults without cognitive impairment versus cognitive impairment without dementia versus dementia before intracerebral haemorrhage, stratified by lobar and non-lobar intracerebral haemorrhage. In non-lobar intracerebral haemorrhage, severe cortical atrophy was less common in those without cognitive impairment (8/36, 22%) and cognitive impairment without dementia (0/9, 0%) versus dementia (5/9, 56%); P = 0.008. Irrespective of intracerebral haemorrhage location, adults without cognitive impairment had milder neurofibrillary tangle pathology measured by median Braak stage (lobar intracerebral haemorrhage: no cognitive impairment 2 [interquartile range, 2-3] versus cognitive impairment without dementia 4 [2-6] versus dementia 5.5 [4-6]; P = 0.004; non-lobar intracerebral haemorrhage: no cognitive impairment 2 [1-2] versus cognitive impairment without dementia 2 [1-2] versus dementia 5 [3-6]; P < 0.001). Irrespective of intracerebral haemorrhage location, adults without cognitive impairment had milder amyloid plaque pathology measured by median Thal stage (lobar intracerebral haemorrhage: no cognitive impairment 2 [1-2] versus cognitive impairment without dementia 2 [2-3] versus dementia 2.5 [2-3.5]; P = 0.033; non-lobar intracerebral haemorrhage: no cognitive impairment 1 [0-1] versus cognitive impairment without dementia 0 [0-2] versus dementia 3 [2-3]; P = 0.002). Our findings suggest that irrespective of intracerebral haemorrhage location, adults with cognitive impairment before an intracerebral haemorrhage have more Alzheimer's disease neuropathologic change.

Cerebral Small Vessel Disease and Infarct Growth in Acute Ischemic Stroke Treated with Intravenous Thrombolysis

We investigated relations between cerebral small vessel disease (cSVD) markers and evolution of the ischemic tissue from ischemic core to final infarct in people with acute ischemic stroke treated with intravenous thrombolysis. Data from the Stroke Imaging Repository (STIR) and Virtual International Stroke Trials Archive (VISTA) were used. Any pre-existing lacunar infarcts and white matter hyperintensities (WMH) were assessed on magnetic resonance (MR) before thrombolytic therapy. Acute ischemic core and final infarct volume were then assessed by two independent radiologists. The relationship among baseline markers of cSVD, acute ischemic core volume, final infarct volume, infarct growth (IG = final infarct - ischemic core), and infarct growth ratio (IGR = final infarct/ischemic core) was then assessed using linear and ordinal regression adjusted for age, sex, onset-to-treatment time, and stroke severity. We included 165 patients, mean (± SD) age 69.5 (± 15.7) years, 74 (45%) males, mean (± SD) ischemic core volume 25.48 (± 42.22) ml, final infarct volume 52.06 (± 72.88) ml, IG 26.58 (± 51.02) ml, IGR 8.23 (± 38.12). Seventy (42%) patients had large vessel occlusion, 20 (12%) acute small subcortical infarct. WMHs were present in 131 (79%) and lacunar infarcts in 61 (37%) patients. Final infarct volumes were 53.8 ml and 45.2 ml (WMHs/no WMHs), p = 0.139, and 24.6 ml and 25.9 ml (lacunar infarcts/no lacunar infarcts), p = 0.842. In linear and ordinal regression analyses, presence of lacunar infarcts was associated with smaller IG (β =  - 0.17; p = 0.024; cOR = 0.52; 95%CI = 0.28-0.96, respectively) and WMHs were associated with smaller IGR (β =  - 0.30; p = 0.004; cOR = 0.27; 95%CI = 0.11-0.69, respectively). In people with acute ischemic stroke treated with intravenous thrombolysis, cSVD features were associated with smaller growth of the acute ischemic area, suggesting less salvageable tissue at time of reperfusion therapy.

Cognitive impairment in cerebral small vessel disease induced by hypertension

ABSTRACT

Hypertension is a primary risk factor for the progression of cognitive impairment caused by cerebral small vessel disease, the most common cerebrovascular disease. However, the causal relationship between hypertension and cerebral small vessel disease remains unclear. Hypertension has substantial negative impacts on brain health and is recognized as a risk factor for cerebrovascular disease. Chronic hypertension and lifestyle factors are associated with risks for stroke and dementia, and cerebral small vessel disease can cause dementia and stroke. Hypertension is the main driver of cerebral small vessel disease, which changes the structure and function of cerebral vessels via various mechanisms and leads to lacunar infarction, leukoaraiosis, white matter lesions, and intracerebral hemorrhage, ultimately resulting in cognitive decline and demonstrating that the brain is the target organ of hypertension. This review updates our understanding of the pathogenesis of hypertension-induced cerebral small vessel disease and the resulting changes in brain structure and function and declines in cognitive ability. We also discuss drugs to treat cerebral small vessel disease and cognitive impairment.

Impact of cerebral small vessel disease burden and drug level at admission on direct oral anticoagulant associated intracerebral hemorrhage

INTRODUCTION

Direct oral anticoagulant (DOAC)-associated intracerebral hemorrhage (ICH) is a catastrophic complication. The aim of this study was to investigate the association between computed tomography (CT)-based cerebrovascular small vessel disease (SVD) burden and DOAC-ICH as well as the DOAC concentration upon hospital admission and ICH outcome.

PATIENTS AND METHODS

The study included two cohorts: (1) DOAC-ICH: patients who suffered from DOAC-ICH and underwent drug level measurements upon admission; (2) DOAC-non-ICH: stable DOAC users who underwent head CT without ICH during treatment. We categorized the DOAC levels of the DOAC-ICH patients as low (<50 ng/mL), medium (50-300 ng/mL), and high (>300 ng/mL). The CT-based SVD burden (including white matter lesions [WML], lacunes, and cerebral atrophy) was evaluated, and SVD scores (range, 0-3) were used to evaluate SVD severity.

RESULTS

A total of 43 DOAC-ICH patients and 177 DOAC-non-ICH patients were enrolled. DOAC-ICH patients were more likely to have WML, lacunes, or cerebral atrophy compared to DOAC-non-ICH patients. After adjustment, the SVD burden was associated with DOAC-ICH, with a higher risk of more severe SVD (SVD score of 2; odds ratio [OR], 10.3 [3.17, 33.3]; score of 3; OR, 16.8 [4.50, 62.6]). The proportions of patients with high, medium, and low drug levels in the DOAC-ICH group were 16.3%, 55.8%, and 27.9%, respectively. Additionally, the high-level group displayed a larger hematoma size and had worse functional outcomes at 3 months than the other two groups.

DISCUSSION AND CONCLUSION

The severity of SVD burden was associated with DOAC-ICH. Furthermore, high DOAC levels in ICH were associated with unfavorable clinical outcomes. To address the potential selection bias from these two cohorts, a prospective study to investigate the co-contribution of drug levels and SVD to DOAC-ICH is essential.

Therapeutic potential of mesenchymal stem cells for cerebral small vessel disease

Cerebral small vessel disease (CSVD), as the most common, chronic and progressive vascular disease on the brain, is a serious neurological disease, whose pathogenesis remains unclear. The disease is a leading cause of stroke and vascular cognitive impairment and dementia, and contributes to about 20% of strokes, including 25% of ischemic strokes and 45% of dementias. Undoubtedly, the high incidence and poor prognosis of CSVD have brought a heavy economic and medical burden to society. The present treatment of CSVD focuses on the management of vascular risk factors. Although vascular risk factors may be important causes or accelerators of CSVD and should always be treated in accordance with best clinical practice, controlling risk factors alone could not curb the progression of CSVD brain injury. Therefore, developing safer and more effective treatment strategies for CSVD is urgently needed. Recently, mesenchymal stem cells (MSCs) therapy has become an emerging therapeutic modality for the treatment of central nervous system disease, given their paracrine properties and immunoregulatory. Herein, we discussed the therapeutic potential of MSCs for CSVD, aiming to enable clinicians and researchers to understand of recent progress and future directions in the field.

A bibliometric analysis of international publication trends in brain atrophy research (2008-2023)

Background

Brain atrophy is a type of neurological and psychiatric disorder characterized by a decrease in brain tissue volume and weight for various reasons and can have a serious impact on the quality of life of patients. Although there are many studies on brain atrophy, there is a lack of relevant bibliometric studies. Therefore, this study aims to provide a visual analysis of global trends in brain atrophy research over the past 16 years.

Methods

CiteSpace and VOSviewer were used to visually analyze publication output, scientific collaborations, cocitations, publishing journals, and keywords to determine the current status and future trends of brain atrophy research. Materials published from 2008 to 2023 were collected from the Web of Science Core Collection (WoSCC) database. This study placed no restrictions on the types of literature and focused on English language publications.

Results

A total of 3,371 publications were included in the analysis. From 2008 to 2023, the number of publications increased annually. In terms of national and academic institutions, universities in the United States and University College London rank first in publication out. Barkhof Frederik and Zivadinov Robert are the most prolific researchers in this field. The publication with the highest cocitation strength is "Deep gray matter volume loss drives disability worsening in multiple sclerosis." Keyword clustering analysis showed that "Alzheimer's disease" and "multiple sclerosis" are current popular topics. The analysis of emergent words indicates that "cerebral small vessel disease," "neurodegeneration," and "cortex/gray matter volume" may become hot research topics in the coming years.

Conclusion

This study analyses papers on brain atrophy from the past 16 years, providing a new perspective for research in this field. In the past 16 years, research on brain atrophy has received increasing attention. The quality of articles in this field is generally high. Extensive national cooperation already exists. The statistical results indicate that a stable core author group in the field of brain atrophy has almost formed.

Associations of renal function with cerebral small vessel disease and functional outcome in acute intracerebral haemorrhage: A hospital-based prospective cohort study

BACKGROUND

Intracerebral haemorrhage (ICH) is a severe clinical consequence of cerebral small vessel disease (SVD), but associations between renal impairment and SVD in patients with ICH have not been fully characterised.

METHODS

Using data from the CROMIS-2 ICH observational study, we compared SVD neuroimaging markers and total burden (score 0-3) identified using CT brain imaging in patients with and without renal impairment (estimated glomerular filtration rate, eGFR<60). We assessed functional outcome at 6-month follow-up using the modified Rankin scale.

RESULTS

1027 participants were included (mean age 72.8, 57.1% male); 274 with and 753 without renal impairment. 18.7% of the eGFR<60 group had moderate-to-severe SVD burden (score 2-3), compared with 14.0% of those with eGFR>60 (p = 0.039). SVD burden was associated with renal impairment after adjusting for hypertension (OR 1.36, 95% CI 1.04-1.77, p = 0.023), but not after adjusting for age. Cerebral atrophy was more prevalent in patients with eGFR<60 (81.2% vs. 72.0%, p = 0.002), as were WMH (45.6% vs. 36.6%, p = 0.026). Neither was associated with renal function after adjusting for age and vascular risk factors. Renal impairment was associated with functional outcome (OR 0.65, 95% CI 0.47-0.89, p = 0.007), but not after adjusting for age, pre-morbid function and comorbidities (OR 0.95, 95% CI 0.65-1.38, p = 0.774).

CONCLUSION

In acute ICH, renal impairment is associated with a higher cerebral SVD burden independent of hypertension, but not age. Reduced eGFR is associated with worse functional outcome, but not independent of age and comorbidities. Since CT has limited sensitivity to detect SVD severity and distribution, further studies including MRI are needed.

Associations of Cerebral Small Vessel Disease on the Features of Hematoma and Hematoma Expansion in Intracerebral Hemorrhage

INTRODUCTION

Several early noncontrast CT (NCCT) signs of spontaneous intracerebral hemorrhage (ICH) can predict hematoma expansion (HE). However, the associations of underlying cerebral small vessel disease (SVD) on early NCCT signs and HE have been less explored.

METHODS

We conducted an analysis of all patients with spontaneous supratentorial ICH and received follow-up imaging between 2016 and 2020 at a stroke center. The early NCCT signs were categorized as shape or density signs. HE was defined as an increase in hematoma volume ≥6 mL or 33% from baseline. The severity of SVD was assessed by both a 3-point CT-based and a 4-point magnetic resonance imaging (MRI)-based SVD score. Regression models were used to examine the associations between SVD score and hematoma volume, NCCT signs, and HE.

RESULTS

A total of 328 patients (median age: 64 years; 38% female) were included. The median baseline ICH volume was 8.6 mL, with 38% of the patients had shape signs and 52% had density signs on the initial NCCT. Higher MRI-SVD scores were associated with smaller ICH volumes (p = 0.0006), fewer shape (p = 0.001), or density signs (p = 0.0003). Overall, 16% of patients experienced HE. A higher MRI-SVD score was inversely associated with HE (adjusted odds ratio 0.71, 95% CI: 0.53-0.96). Subgroup analysis revealed that this association was primarily observed in patients who were younger (<65 years), male, had deep hemorrhage, or did not meet the criteria for cerebral amyloid angiopathy diagnosis.

CONCLUSIONS

In patients with spontaneous ICH, a more severe SVD was associated with smaller hematoma volume, fewer NCCT signs, and a lower risk of HE. Further research is required to investigate why a higher burden of severely diseased cerebral small blood vessels is associated with less bleeding.

Associations between computed tomography markers of cerebral small vessel disease and hemorrhagic transformation after intravenous thrombolysis in acute ischemic stroke patients

Background

Hemorrhagic transformation (HT) is common among acute ischemic stroke patients after treatment with intravenous thrombolysis (IVT). We analyzed potential relationships between markers of cerebral small vessel disease (CSVD) and HT in patients after IVT.

Methods

This study retrospectively analyzed computed tomography (CT) data for acute ischemic stroke patients before and after treatment with recombinant tissue plasminogen activator at a large Chinese hospital between July 2014 and June 2021. Total CSVD score were summed by individual CSVD markers including leukoaraiosis, brain atrophy and lacune. Binary regression analysis was used to explore whether CSVD markers were related to HT as the primary outcome or to symptomatic intracranial hemorrhage (sICH) as a secondary outcome.

Results

A total of 397 AIS patients treated with IVT were screened for inclusion in this study. Patients with missing laboratory data (n = 37) and patients treated with endovascular therapy (n = 42) were excluded. Of the 318 patients included, 54 (17.0%) developed HT within 24–36 h of IVT, and 14 (4.3%) developed sICH. HT risk was independently associated with severe brain atrophy (OR 3.14, 95%CI 1.43–6.92, P = 0.004) and severe leukoaraiosis (OR 2.41, 95%CI 1.05–5.50, P = 0.036), but not to severe lacune level (OR 0.58, 95%CI 0.23–1.45, P = 0.250). Patients with a total CSVD burden ≥1 were at higher risk of HT (OR 2.87, 95%CI 1.38–5.94, P = 0.005). However, occurrence of sICH was not predicted by CSVD markers or total CSVD burden.

Conclusion

In patients with acute ischemic stroke, severe leukoaraiosis, brain atrophy and total CSVD burden may be risk factors for HT after IVT. These findings may help improve efforts to mitigate or even prevent HT in vulnerable patients.

Critical closing pressure as a new hemodynamic marker of cerebral small vessel diseases burden

Purpose

To investigate cerebrovascular hemodynamics, including critical closing pressure (CrCP) and pulsatility index (PI), and their independent relationship with cerebral small vessel disease (CSVD) burden in patients with small-vessel occlusion (SVO).

Methods

We recruited consecutive patients with SVO of acute cerebral infarction who underwent brain magnetic resonance imaging (MRI), transcranial Doppler (TCD) and CrCP during admission. Cerebrovascular hemodynamics were assessed using TCD. We used the CSVD score to rate the total MRI burden of CSVD. Multiple regression analysis was used to determine parameters related to CSVD burden or CrCP.

Results

Ninety-seven of 120 patients (mean age, 64.51 ± 9.99 years; 76% male) completed the full evaluations in this study. We observed that CrCP was an independent determinant of CSVD burden in four models [odds ratio, 1.41; 95% confidence interval (CI), 1.17-1.71; P < 0.001] and correlated with CSVD burden [β (95% CI): 0.05 (0.04-0.06); P < 0.001]. In ROC analysis, CrCP was considered as a predictor of CSVD burden, and AUC was 86.2% (95% CI, 78.6-93.9%; P < 0.001). Multiple linear regression analysis showed that CrCP was significantly correlated with age [β (95% CI): 0.27 (0.06 to 0.47); P = 0.012], BMI [β (95% CI): 0.61 (0.00-1.22)] and systolic BP [β (95% CI): 0.16 (0.09-0.23); P < 0.001].

Conclusions

CrCP representing cerebrovascular tension is an independent determinant and predictor of CSVD burden. It was significantly correlated with age, BMI and systolic blood pressure. These results provide new insights in the mechanism of CSVD development.

Transcranial Doppler assessment of patients with cerebral small vessel disease

Background

Cerebral small vessel disease (SVD) is associated with acute events such as lacunar and hemorrhagic strokes, or chronic events such as cognitive deficit in the form of subcortical dementia, mood deficit in the form of late onset depression, sphincteric affection, and gait apraxia. Under conditions of moderate blood flow deficit, the inability of sclerotic vessels to dilate due to impairment of the cerebral autoregulation, renders the periventricular white matter seriously ischemic. Therefore, it is important to detect the implications of cerebral large artery disease on the severity of SVD, and the ability of transcranial duplex (TCD) to evaluate it in people at risk.

Methods

Fifty lacunar stroke patients were recruited, and evaluated using MRI brain to assess SVD score, carotid duplex and TCD to assess extracranial and intracranial stenoses, respectively.

Results

Both intracranial and extracranial stenoses showed significant relation to the severity of cerebral SVD. Moreover, there were significant relation between intracranial stenosis and presence of lacuna and EPVS.

Conclusion

Cerebral large artery disease contributes to the pathogenesis and severity of cerebral SVD. Therefore, TCD may be a useful tool for the prediction of occurrence of cerebral SVD in high-risk individuals, especially hypertensives.

A new nomogram including total cerebral small vessel disease burden for individualized prediction of early-onset depression in patients with acute ischemic stroke

Objectives

The present study was designed to evaluate the effects of total cerebral small vessel disease (CSVD) on early-onset depression after acute ischemic stroke (AIS), and to develop a new nomogram including total CSVD burden to predict early-onset post-stroke depression (PSD).

Methods

We continuously enrolled patients with AIS who were hospitalized at the First Affiliated Hospital of Soochow University between October 2017 and June 2019. All patients were assessed for depressive symptoms using the 17-item Hamilton Depression Scale (HAMD-17) at 14 ± 2 days after the onset of AIS. The diagnosis for depression was made according to the American Diagnostic and Statistical Manual of Mental Disorders Version 5 (DSM-5). The demographic and clinical data were collected including total CSVD burden. On the basis of a multivariate logistic model, the independent factors of early-onset PSD were identified and the predictive nomogram was generated. The performance of the nomogram was evaluated by Harrell's concordance index (C-index) and calibration plot.

Results

A total of 346 patients were enrolled. When contrasted to a 0 score of total CSVD burden, the score ≥2 (moderate to severe total CSVD burden) was an independent risk factor for early-onset PSD. Besides, gender, cognitive impairments, baseline Barthel Index (BI), and plasma fibrinogen were independently associated with early-onset PSD. The nomogram based on all these five independent risk factors was developed and validated with an Area Under Curve (AUC) of 0.780. In addition, the calibration plot revealed an adequate fit of the nomogram in predicting the risk of early-onset depression in patients with AIS.

Conclusions

Our study found the total CSVD burden score of 2–4 points was an independent risk factor of early-onset PSD. The proposed nomogram based on total CSVD burden, gender, cognitive impairments, baseline BI, and plasma fibrinogen concentration gave rise to a more accurate and more comprehensive prediction for early-onset PSD.

The triglyceride glucose index is associated with the cerebral small vessel disease in a memory clinic population

BACKGROUND AND OBJECTIVES

Insulin resistance (IR) has been associated with the cerebral small vessel disease (cSVD). However, as the surrogate marker of IR, there is little known about the relationship between the triglyceride glucose (TyG) index and cSVD. In this cross-sectional study, we aimed to evaluate the relationship between the TyG index and cSVD in a memory clinic population and explore the value of TyG index to improve the risk stratification of cSVD.

METHODS

We included participants who attended our memory clinic from January 2016 to December 2020. TyG index was determined as ln [fasting triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2]. We assessed lacunes, microbleeds, white matter hyperintensity (WMH) and enlarged perivascular spaces (EPVS) on MRI and calculated the total cSVD burden.

RESULTS

A total of 297 subjects were included (median age: 65 years, male sex: 64.98%). In the adjusted model, when dividing TyG index into quartiles, subjects with TyG index in the top quartile, compared with those in the bottom quartile, were more likely to have lacunes (P = 0.035), moderate-severe WMH (P = 0.001), a higher grade of deep WMH (P = 0.004), a higher grade of PVWMH (P = 0.032), a higher grade of EPVS (P = 0.002), and a higher cSVD score (P < 0.001). When introducing TyG index into traditional risk factors to predict moderate to severe cSVD, both area under the curve (0.745 vs 0.802, P = 0.003) and integrated discrimination index (0.080, 95% CI 0.050-0.110, P < 0.001) displayed an improvement from TyG index.

CONCLUSIONS

The TyG index is correlated with cSVD and may have the potential to be a surrogate marker of insulin resistance and optimize the risk stratification.

Test-retest reliability of arterial spin labelling for cerebral blood flow in older adults with small vessel disease

Cerebral small vessel disease (SVD) is common in older people and is associated with lacunar stroke, white matter hyperintensities (WMH) and vascular cognitive impairment. Cerebral blood flow (CBF) is reduced in SVD, particularly within white matter.Here we quantified test-retest reliability in CBF measurements using pseudo-continuous arterial spin labelling (pCASL) in older adults with clinical and radiological evidence of SVD (N=54, mean (SD): 66.9 (8.7) years, 15 females/39 males). We generated whole-brain CBF maps on two visits at least 7 days apart (mean (SD): 20 (19), range 7-117 days).Test-retest reliability for CBF was high in all tissue types, with intra-class correlation coefficient [95%CI]: 0.758 [0.616, 0.852] for whole brain, 0.842 [0.743, 0.905] for total grey matter, 0.771 [0.636, 0.861] for deep grey matter (caudate-putamen and thalamus), 0.872 [0.790, 0.923] for normal-appearing white matter (NAWM) and 0.780 [0.650, 0.866] for WMH (all p<0.001). ANCOVA models indicated significant decline in CBF in total grey matter, deep grey matter and NAWM with increasing age and diastolic blood pressure (all p<0.001). CBF was lower in males relative to females (p=0.013 for total grey matter, p=0.004 for NAWM).We conclude that pCASL has high test-retest reliability as a quantitative measure of CBF in older adults with SVD. These findings support the use of pCASL in routine clinical imaging and as a clinical trial endpoint.All data come from the PASTIS trial, prospectively registered at: https://eudract.ema.europa.eu (2015-001235-20, registered 13/05/2015), http://www.clinicaltrials.gov (NCT02450253, registered 21/05/2015).

The Spatiotemporal Dynamics of Cerebral Autoregulation in Functional Magnetic Resonance Imaging

The thigh-cuff release (TCR) maneuver is a physiological challenge that is widely used to assess dynamic cerebral autoregulation (dCA). It is often applied in conjunction with Transcranial Doppler ultrasound (TCD), which provides temporal information of the global flow response in the brain. This established method can only yield very limited insights into the regional variability of dCA, whereas functional MRI (fMRI) has the ability to reveal the spatial distribution of flow responses in the brain with high spatial resolution. The aim of this study was to use whole-brain blood-oxygenation-level-dependent (BOLD) fMRI to characterize the spatiotemporal dynamics of the flow response to the TCR challenge, and thus pave the way toward mapping dCA in the brain. We used a data driven approach to derive a novel basis set that was then used to provide a voxel-wise estimate of the TCR associated haemodynamic response function (HRF TCR ). We found that the HRF TCR evolves with a specific spatiotemporal pattern, with gray and white matter showing an asynchronous response, which likely reflects the anatomical structure of cerebral blood supply. Thus, we propose that TCR challenge fMRI is a promising method for mapping spatial variability in dCA, which will likely prove to be clinically advantageous.

The Underlying Role of the Glymphatic System and Meningeal Lymphatic Vessels in Cerebral Small Vessel Disease

There is a growing prevalence of vascular cognitive impairment (VCI) worldwide, and most research has suggested that cerebral small vessel disease (CSVD) is the main contributor to VCI. Several potential physiopathologic mechanisms have been proven to be involved in the process of CSVD, such as blood-brain barrier damage, small vessels stiffening, venous collagenosis, cerebral blood flow reduction, white matter rarefaction, chronic ischaemia, neuroinflammation, myelin damage, and subsequent neurodegeneration. However, there still is a limited overall understanding of the sequence and the relative importance of these mechanisms. The glymphatic system (GS) and meningeal lymphatic vessels (mLVs) are the analogs of the lymphatic system in the central nervous system (CNS). As such, these systems play critical roles in regulating cerebrospinal fluid (CSF) and interstitial fluid (ISF) transport, waste clearance, and, potentially, neuroinflammation. Accumulating evidence has suggested that the glymphatic and meningeal lymphatic vessels played vital roles in animal models of CSVD and patients with CSVD. Given the complexity of CSVD, it was significant to understand the underlying interaction between glymphatic and meningeal lymphatic transport with CSVD. Here, we provide a novel framework based on new advances in main four aspects, including vascular risk factors, potential mechanisms, clinical subtypes, and cognition, which aims to explain how the glymphatic system and meningeal lymphatic vessels contribute to the progression of CSVD and proposes a comprehensive insight into the novel therapeutic strategy of CSVD.

Assessment of microvascular rarefaction in human brain disorders using physiological magnetic resonance imaging

Cerebral microvascular rarefaction, the reduction in number of functional or structural small blood vessels in the brain, is thought to play an important role in the early stages of microvascular related brain disorders. A better understanding of its underlying pathophysiological mechanisms, and methods to measure microvascular density in the human brain are needed to develop biomarkers for early diagnosis and to identify targets for disease modifying treatments. Therefore, we provide an overview of the assumed main pathophysiological processes underlying cerebral microvascular rarefaction and the evidence for rarefaction in several microvascular related brain disorders. A number of advanced physiological MRI techniques can be used to measure the pathological alterations associated with microvascular rarefaction. Although more research is needed to explore and validate these MRI techniques in microvascular rarefaction in brain disorders, they provide a set of promising future tools to assess various features relevant for rarefaction, such as cerebral blood flow and volume, vessel density and radius and blood-brain barrier leakage.

Cerebral Small Vessel Disease and Prognosis in Intracerebral Hemorrhage: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

To investigate whether cerebral small vessel disease (CSVD) markers and the total CSVD burden are associated with functional outcome, mortality, stroke recurrence, and hematoma expansion in patients with spontaneous intracerebral hemorrhage (ICH).

METHODS

Following a previously registered protocol (PROSPERO protocol: CRD42021287743), we systematically searched PubMed, Web of Science, and EMBASE to identify relevant literature up to November 2021. Cohort studies that examined the association between CSVD markers (white matter hyperintensity [WMH], lacune, enlarged perivascular space [EPVS], cerebral microbleed [CMB], and brain atrophy) or CSVD burden and prognosis in patients with ICH were included. The pooled estimates were calculated using random effects models.

RESULTS

Forty-one studies with 19,752 ICH patients were pooled in the meta-analysis. WMH (OR=1.50, 95% CI=1.32 to 1.70), lacune (OR=1.32, 95% CI=1.18 to 1.49), CMB (OR=2.60, 95% CI=1.13 to 5.97) and brain atrophy (OR=2.22, 95% CI=1.48 to 3.31) were associated with worse functional outcome. CSVD markers concerning increased risk of mortality were WMH (OR=1.57, 95% CI=1.38 to 1.79) and brain atrophy (OR=1.84, 95% CI=1.11 to 3.04), while concerning increased risk of stroke recurrence were WMH (OR=1.62, 95% CI=1.28 to 2.04) and lacune (OR=3.00, 95% CI=1.68 to 5.37). EPVS was not related to prognosis. There was a lack of association between CSVD markers and hematoma expansion. CSVD burden increased the risk of worse functional outcome, mortality, and stroke recurrence by 57%, 150%, and 44%, respectively.

CONCLUSIONS

In patients with spontaneous ICH, WMH, lacune, CMB, brain atrophy, and the total CSVD burden are associated with substantially increased risk of worse functional outcome, mortality, or stroke recurrence.

Cerebral Vascular Dysfunctions Detected in Human Small Vessel Disease and Implications for Preclinical Studies

Cerebral small vessel disease (SVD) is highly prevalent and a common cause of ischemic and hemorrhagic stroke and dementia, yet the pathophysiology is poorly understood. Its clinical expression is highly varied, and prognostic implications are frequently overlooked in clinics; thus, treatment is currently confined to vascular risk factor management. Traditionally, SVD is considered the small vessel equivalent of large artery stroke (occlusion, rupture), but data emerging from human neuroimaging and genetic studies refute this, instead showing microvessel endothelial dysfunction impacting on cell-cell interactions and leading to brain damage. These dysfunctions reflect defects that appear to be inherited and secondary to environmental exposures, including vascular risk factors. Interrogation in preclinical models shows consistent and converging molecular and cellular interactions across the endothelial-glial-neural unit that increasingly explain the human macroscopic observations and identify common patterns of pathology despite different triggers. Importantly, these insights may offer new targets for therapeutic intervention focused on restoring endothelial-glial physiology.

Tracer kinetic assessment of blood-brain barrier leakage and blood volume in cerebral small vessel disease: Associations with disease burden and vascular risk factors

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Permeability surface area (PS) was higher, even in normal appearing tissue.

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PS was higher in patients with more white matter hyperintensities.

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Tissue damage affecting vascular surface area may affect how we interpret tracer kinetic results.

Subtle blood–brain barrier (BBB) permeability increases have been shown in small vessel disease (SVD) using various analysis methods. Following recent consensus recommendations, we used Patlak tracer kinetic analysis, considered optimal in low permeability states, to quantify permeability-surface area product (PS), a BBB leakage estimate, and blood plasma volume (v_P) in 201 patients with SVD who underwent dynamic contrast-enhanced MRI scans. We ran multivariable regression models with a quantitative or qualitative metric of white matter hyperintensity (WMH) severity, demographic and vascular risk factors. PS increased with WMH severity in grey (B = 0.15, Confidence Interval (CI): [0.001,0.299], p = 0.049) and normal-appearing white matter (B = 0.015, CI: [−0.008,0.308], p = 0.062). Patients with more severe WMH had lower v_P in WMH (B = -0.088, CI: [−0.138,-0.039], p < 0.001), but higher v_P in normal-appearing white matter (B = 0.031, CI: [−0.004,0.065], p = 0.082). PS and v_P were lower at older ages in WMH, grey and white matter. We conclude higher PS in normal-appearing tissue with more severe WMH suggests impaired BBB integrity beyond visible lesions indicating that the microvasculature is compromised in normal-appearing white matter and WMH. BBB dysfunction is an important mechanism in SVD, but associations with clinical variables are complex and underlying damage affecting vascular surface area may alter interpretation of tracer kinetic results.

Apixaban versus no anticoagulation after anticoagulation-associated intracerebral haemorrhage in patients with atrial fibrillation in the Netherlands (APACHE-AF): a randomised, open-label, phase 2 trial

BACKGROUND

In patients with atrial fibrillation who survive an anticoagulation-associated intracerebral haemorrhage, a decision must be made as to whether restarting or permanently avoiding anticoagulation is the best long-term strategy to prevent recurrent stroke and other vascular events. In APACHE-AF, we aimed to estimate the rates of non-fatal stroke or vascular death in such patients when treated with apixaban compared with when anticoagulation was avoided, to inform the design of a larger trial.

METHODS

APACHE-AF was a prospective, randomised, open-label, phase 2 trial with masked endpoint assessment, done at 16 hospitals in the Netherlands. Patients who survived intracerebral haemorrhage while treated with anticoagulation for atrial fibrillation were eligible for inclusion 7-90 days after the haemorrhage. Participants also had a CHA₂DS₂-VASc score of at least 2 and a score on the modified Rankin scale (mRS) of 4 or less. Participants were randomly assigned (1:1) to receive oral apixaban (5 mg twice daily or a reduced dose of 2·5 mg twice daily) or to avoid anticoagulation (oral antiplatelet agents could be prescribed at the discretion of the treating physician) by a central computerised randomisation system, stratified by the intention to start or withhold antiplatelet therapy in participants randomised to avoiding anticoagulation, and minimised for age and intracerebral haemorrhage location. The primary outcome was a composite of non-fatal stroke or vascular death, whichever came first, during a minimum follow-up of 6 months, analysed using Cox proportional hazards modelling in the intention-to-treat population. APACHE-AF is registered with ClinicalTrials.gov (NCT02565693) and the Netherlands Trial Register (NL4395), and the trial is closed to enrolment at all participating sites.

FINDINGS

Between Jan 15, 2015, and July 6, 2020, we recruited 101 patients (median age 78 years [IQR 73-83]; 55 [54%] were men and 46 [46%] were women; 100 [99%] were White and one [1%] was Black) a median of 46 days (IQR 21-74) after intracerebral haemorrhage. 50 were assigned to apixaban and 51 to avoid anticoagulation (of whom 26 [51%] started antiplatelet therapy). None were lost to follow-up. Over a median follow-up of 1·9 years (IQR 1·0-3·1; 222 person-years), non-fatal stroke or vascular death occurred in 13 (26%) participants allocated to apixaban (annual event rate 12·6% [95% CI 6·7-21·5]) and in 12 (24%) allocated to avoid anticoagulation (11·9% [95% CI 6·2-20·8]; adjusted hazard ratio 1·05 [95% CI 0·48-2·31]; p=0·90). Serious adverse events that were not outcome events occurred in 29 (58%) of 50 participants assigned to apixaban and 29 (57%) of 51 assigned to avoid anticoagulation.

INTERPRETATION

Patients with atrial fibrillation who had an intracerebral haemorrhage while taking anticoagulants have a high subsequent annual risk of non-fatal stroke or vascular death, whether allocated to apixaban or to avoid anticoagulation. Our data underline the need for randomised controlled trials large enough to allow identification of subgroups in whom restarting anticoagulation might be either beneficial or hazardous.

FUNDING

Dutch Heart Foundation (grant 2012T077).

Carotid revascularization and cognitive impairment: the neglected role of cerebral small vessel disease

Carotid atherosclerosis is a pathological process that leads to narrowing of the vessel lumen and a consequent risk of stroke. Revascularization procedures such as carotid endarterectomy (CEA) and carotid stenting aim to reduce occurrence of stroke in selected patients. Due to the proven benefit and low intraoperative risk, CEA is currently the preferred choice in candidates for carotid revascularization. However, the risk of cognitive impairment subsequent to CEA has not been fully elucidated and is unclear whether certain conditions, such as frailty, may increase this risk. There is consistent evidence that shows that frail patients have higher risk of cognitive impairment after surgical procedure. Moreover, brain pre-existing conditions may play a role in cognitive impairment after CEA. Cerebral small vessel disease (SVD) is a pathology that involves microcirculation and is detectable with computed tomography or magnetic resonance. SVD shares common vascular risk factors with carotid atherosclerosis, is a major contributor to vascular cognitive impairment and vascular dementia, and has been proposed as a marker of brain frailty. In this review, we discuss the current evidence about the link between carotid revascularization and cognitive impairment and advance the hypothesis that SVD may play a relevant role in development of cognitive impairment after carotid revascularization.

Associations Between White Matter Hyperintensity Burden, Cerebral Blood Flow and Transit Time in Small Vessel Disease: An Updated Meta-Analysis

Cerebral small vessel disease (SVD) is a major contributor to stroke and dementia, characterized by white matter hyperintensities (WMH) on neuroimaging. WMH are associated with reduced cerebral blood flow (CBF) cross-sectionally, though longitudinal associations remain unclear. We updated a 2016 systematic review, identifying 30 new studies, 27 cross-sectional (n = 2,956) and 3 longitudinal (n = 440). Cross-sectionally, 10/27 new studies (n = 1,019) included sufficient data for meta-analysis, which we meta-analyzed with 24 previously reported studies (n = 1,161), total 34 (n = 2,180). Our meta-analysis showed that patients with lower CBF had worse WMH burden (mean global CBF: standardized mean difference (SMD): −0.45, 95% confidence interval (CI): −0.64, −0.27). Longitudinally, associations between baseline CBF and WMH progression varied: the largest study (5 years, n = 252) found no associations, while another small study (4.5 years, n = 52) found that low CBF in the periventricular WMH penumbra predicted WMH progression. We could not meta-analyse longitudinal studies due to different statistical and methodological approaches. We found that CBF was lower in WMH than in normal-appearing white matter in an additional meta-analysis (5 cross-sectional studies; n = 295; SMD: −1.51, 95% CI: −1.94, −1.07). These findings highlight that relationships between resting CBF and WMH are complex. Further longitudinal studies analyzing regional CBF and subsequent WMH change are required to determine the role of CBF in SVD progression.

Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants

OBJECTIVE

We investigated the contribution of small vessel disease (SVD) to anticoagulant-associated intracerebral haemorrhage (ICH).

METHODS

Clinical Relevance of Microbleeds in Stroke-2 comprised two independent multicentre observation studies: first, a cross-sectional study of patients with ICH; and second, a prospective study of patients taking anticoagulants for atrial fibrillation (AF) after cerebral ischaemia. In patients with ICH, we compared SVD markers on CT and MRI according to prior anticoagulant therapy. In patients with AF and cerebral ischaemia treated with anticoagulants, we compared the rates of ICH and ischaemic stroke according to SVD burden score during 2 years follow-up.

RESULTS

We included 1030 patients with ICH (421 on anticoagulants), and 1447 patients with AF and cerebral ischaemia. Medium-to-high severity SVD was more prevalent in patients with anticoagulant-associated ICH (CT 56.1%, MRI 78.7%) than in those without prior anticoagulant therapy (CT 43.5%, p<0.001; MRI 64.5%, p=0.072). Leukoaraiosis and atrophy were more frequent and severe in ICH associated with prior anticoagulation. In the cerebral ischaemia cohort (779 with SVD), during 3366 patient-years of follow-up the rate of ICH was 0.56%/year (IQR 0.27-1.03) in patients with SVD, and 0.06%/year (IQR 0.00-0.35) in those without (p=0.001); ICH was independently associated with severity of SVD (HR 5.0, 95% CI 1.9 to 12.2,p=0.001), and was predicted by models including SVD (c-index 0.75, 95% CI 0.63 to 0.85).

CONCLUSIONS

Medium-to-high severity SVD is associated with ICH occurring on anticoagulants, and independently predicts ICH in patients with AF taking anticoagulants; its absence identifies patients at low risk of ICH. Findings from these two complementary studies suggest that SVD is a contributory factor in ICH in patients taking anticoagulants and suggest that anticoagulation alone should no longer be regarded as a sufficient 'cause' of ICH.

TRIAL REGISTRATION

NCT02513316.

Cerebral Small Vessel Disease and Functional Outcome Prediction After Intracerebral Hemorrhage

OBJECTIVE

To determine whether CT-based cerebral small vessel disease (SVD) biomarkers are associated with 6-month functional outcome after intracerebral hemorrhage (ICH) and whether these biomarkers improve the performance of the preexisting ICH prediction score.

METHODS

We included 864 patients with acute ICH from a multicenter, hospital-based prospective cohort study. We evaluated CT-based SVD biomarkers (white matter hypodensities [WMH], lacunes, brain atrophy, and a composite SVD burden score) and their associations with poor 6-month functional outcome (modified Rankin Scale score >2). The area under the receiver operating characteristic curve (AUROC) and Hosmer-Lemeshow test were used to assess discrimination and calibration of the ICH score with and without SVD biomarkers.

RESULTS

In multivariable models (adjusted for ICH score components), WMH presence (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.12-2.06), cortical atrophy presence (OR 1.80, 95% CI 1.19-2.73), deep atrophy presence (OR 1.66, 95% CI 1.17-2.34), and severe atrophy (either deep or cortical) (OR 1.94, 95% CI 1.36-2.74) were independently associated with poor functional outcome. For the revised ICH score, the AUROC was 0.71 (95% CI 0.68-0.74). Adding SVD markers did not significantly improve ICH score discrimination; for the best model (adding severe atrophy), the AUROC was 0.73 (95% CI 0.69-0.76). These results were confirmed when lobar and nonlobar ICH were considered separately.

CONCLUSIONS

The ICH score has acceptable discrimination for predicting 6-month functional outcome after ICH. CT biomarkers of SVD are associated with functional outcome, but adding them does not significantly improve ICH score discrimination.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02513316.

Samarasekera N, Lerpiniere C, Perry LA, Moullaali TJ, J.M. Loan J, Wardlaw JM, Al‐Shahi Salman R. Association between Computed Tomographic Biomarkers of Cerebral Small Vessel Diseases and Long-Term Outcome after Spontaneous Intracerebral Hemorrhage

OBJECTIVE

A study was undertaken to assess whether cerebral small vessel disease (SVD) computed tomographic (CT) biomarkers are associated with long-term outcome after intracerebral hemorrhage.

METHODS

We performed a prospective, community-based cohort study of adults diagnosed with spontaneous intracerebral hemorrhage between June 1, 2010 and May 31, 2013. A neuroradiologist rated the diagnostic brain CT for acute intracerebral hemorrhage features and SVD biomarkers. We used severity of white matter lucencies and cerebral atrophy, and the number of lacunes to calculate the CT SVD score. We assessed the association between CT SVD biomarkers and either death, or death or dependence (modified Rankin Scale scores = 4-6) 1 year after first-ever intracerebral hemorrhage using logistic regression, adjusting for known predictors of outcome.

RESULTS

Within 1 year of intracerebral hemorrhage, 224 (56%) of 402 patients died. In separate models, 1-year death was associated with severe atrophy (adjusted odds ratio [aOR] = 2.54, 95% confidence interval [CI] = 1.44-4.49, p = 0.001) but not lacunes or severe white matter lucencies, and CT SVD sum score ≥ 1 (aOR = 2.50, 95% CI = 1.40-4.45, p = 0.002). Two hundred seventy-seven (73%) of 378 patients with modified Rankin Scale data were dead or dependent at 1 year. In separate models, 1-year death or dependence was associated with severe atrophy (aOR = 3.67, 95% CI = 1.71-7.89, p = 0.001) and severe white matter lucencies (aOR = 2.18, 95% CI = 1.06-4.51, p = 0.035) but not lacunes, and CT SVD sum score ≥ 1 (aOR = 2.81, 95% CI = 1.45-5.46, p = 0.002).

INTERPRETATION

SVD biomarkers on the diagnostic brain CT are associated with 1-year death and dependence after intracerebral hemorrhage, independent of known predictors of outcome. ANN NEUROL 2021;89:266-279.

[Clustering of diagnostic MRI signs of cerebral microangiopathy and its relationship with markers of inflammation and angiogenesis]

OBJECTIVE

To perform cluster analysis of MRI signs of cerebral microangiopathy (small vessel disease, SVD) and to clarify the relationship between the isolated groups and circulating markers of inflammation and angiogenesis.

MATERIAL AND METHODS

The identification of groups of MRI signs (MRI types) using cluster hierarchical agglomerative analysis and iterative algorithm of k-means and assessment of their relationship with serum concentrations of tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor-A (VEGF-A), hypoxia-inducible factor 1-α (HIF1-α) determined by ELISA were performed in 96 patients with SVD (STRIVE, 2013) (65 women, average age 60.91±6.57 years).

RESULTS

Cluster analysis of MRI signs identified two MRI types of SVD with Fazekas grade 3 of white matter hyperintensity (WMH). MRI type 1 (n=18; 6 women, mean age 59.1±6.8 years) and MRI type 2 (n=22, 15 f., mean age 63.5±6.2 years) did not differ by age, sex, severity of hypertension, presence of other risk factors. MRI type 1 had a statistically significantly more pronounced WMH in the periventricular regions, multiple lacunes and microbleeds, atrophy, severe cognitive impairment and gait disorders compared with MRI type 2. Its formation was associated with a decrease in VEGF-A level. MRI type 2 had the significantly more pronounced juxtacortical WMH, white matter lacunes, in the absence of microbleeds and atrophy, and less severe clinical manifestations compared with MRI type 1. Its formation was associated with an increase in TNF-α level.

CONCLUSION

Clustering of diagnostic MRI signs into MRI types of SVD with significant differences in the severity of clinical manifestations suggests the pathogenetic heterogeneity of age-related SVD. The relationship of MRI types with circulating markers of different mechanisms of vascular wall and brain damage indicates the dominant role of depletion of angiogenesis in the formation of MRI type 1 and increased inflammation in the formation of MRI type 2. Further studies are needed to clarify the criteria and diagnostic value of differentiation of MRI types of SVD, and also their mechanisms with the definition of pathogenetically justified prevention and treatment of various forms of SVD.

White Matter Hypoperfusion Associated with Leukoaraiosis Predicts Intracranial Hemorrhage after Intravenous Thrombolysis

OBJECTIVES

White matter hyperintensity is common in patients receiving intravenous thrombolysis. Some studies have expressed concern about the increased risk of hemorrhagic transformation and poor prognosis for those patients with pre-existing leukoaraiosis. The purpose of this study was to evaluate hypoperfusion associated with leukoaraiosis before thrombolysis using CT perfusion and to explore whether chronic white matter hypoperfusion increases risks of intracranial hemorrhage and poor clinical prognosis.

MATERIALS AND METHODS

We collected 175 patients underwent intravenous thrombolysis with complete CT perfusion data and follow-up MRI between June 2017 and January 2020. We measured cerebral blood flow, cerebral blood volume, mean transit time and transit time to the peak at both periventricular and subcortical layers in the cerebral hemisphere contralateral to the stroke. The differences of white matter perfusion were compared between groups with different leukoaraiosis severity. Univariate analysis was used to compare in incidence of hemorrhagic transformation and poor prognosis between the hypoperfusion and normal perfusion groups. Further, we examined association between white matter hypoperfusion and intracranial hemorrhage after thrombolysis using logistic regression.

RESULTS

The length of periventricular transit time to the peak was independently associated with a higher risk of intracranial hemorrhage after thrombolysis (OR=4.740, 95%CI=1.624-13.837, P=0.004). The best predictive value was 4.012. But there was no significant difference in poor prognosis at 3 months between hypoperfusion (periventricular transit time to the peak≥4.012 s) and normal perfusion (periventricular transit time to the peak<4.012 s) group.

CONCLUSIONS

Image presentations of white matter hypoperfusion reflected the severity of leukoaraiosis. White matter hypoperfusion was independently associated with intracranial hemorrhage after intravenous thrombolysis. However, hypoperfusion would not increase the risk of poor prognosis.

Relationship between white matter hyperintensities and chronic kidney disease in patients with acute lacunar stroke

BACKGROUND AND PURPOSE

Previous studies have revealed a relationship between chronic kidney disease (CKD) and white matter hyperintensities (WMH). However, studies on the WMH and CKD in acute stroke patients are rare, and the conclusion is consistent. Our study aimed to investigate the relationship between the severity of WMH and CKD in acute lacunar infarction patients.

METHODS

Consecutive acute lacunar infarction patients were recruited in this cross-sectional study. All patients were divided into two groups according to the severity of periventricular WMH (PVWMH) and deep WMH (DWMH). We dichotomized the severity of WMH (PVWMH and DWMH, separately) into mild group (Fazekas scores 0-1) and moderate-severe group (Fazekas scores 2-3). Estimated glomerular filtration rate (eGFR), proteinuria, vascular risk factors, and clinical features were compared between these two groups. Multivariable logistic regression analysis was used to investigate the association between the severity of WMH and risk factors.

RESULTS

A total of 993 acute lacunar infarction patients aged 25-95 years were enrolled. The proportions of participants presenting moderate-severe group PVWMH and DWMH were 46.6% and 38.6%, respectively. Patients with moderate-severe PVWMH had higher age (P < 0.001) and higher incidence of stroke history (P < 0.001) than those in mild group. The level of serum creatinine and the presence of CKD were significantly higher while the eGFR was significantly lower in patients with moderate-severe PVWMH than those with mild PVWMH. Patients with moderate-severe DWMH (n = 383) also had higher age (P < 0.001) and often had a history of stroke (P < 0.001). But the association between the severity of DWMH and eGFR was not found. Multivariable logistic regression analyses showed stage 2 CKD and stage 3 CKD were independently associated with moderate-severe PVWMH, but not DWMH.

CONCLUSIONS

Our study demonstrates that CKD was independently associated with moderate-severe PVWMH in patients with acute lacunar infarction, but not DWMH. PVWMH and DWMH may have distinct pathophysiology.

Alterations of the Whole Cerebral Blood Flow in Patients With Different Total Cerebral Small Vessel Disease Burden

Background

Cerebral small vessel disease (CSVD) is a common age-related vascular disease of the brain associated with slowly accumulating tissue damage. At present, total CSVD burden score is a commonly used method to evaluate the severity of the disease.

Purpose

To observe whether global and regional cerebral perfusion is related to total CSVD score and to explore global and regional cerebral blood flow (CBF) changes in patients with different degrees of CSVD.

Methods

We collected 130 subjects with different total burden score of CSVD (0 point: 33 subjects, 1 point: 39 subjects, 2 points: 24 subjects, 3 points: 24 subjects, 4 points: 10 subjects). Total CSVD burden score was evaluated by clinically routine sequences (T2WI, T2-FLAIR, T1WI, DWI, and SWAN sequence). Global and regional CBF were calculated and correlation analysis was used to investigate the relationship between total CSVD score and CBF of the whole brain and several brain regions.

Results

The analysis results showed that there was a negative correlation between total CSVD burden score and global CBF (r = −0.33, p = 0.001). Total CSVD burden score also had moderately negative correlations with CBF of almost all the brain regions.

Conclusion

CSVD is a disease that affects the whole brain. With the increase of total CSVD burden score, the global and regional CBF decreased. The CSVD total burden score could be used to evaluate the overall condition of brain perfusion.

Cerebral macro- and microcirculatory blood flow dynamics in successfully treated chronic hypertensive patients with and without white mater lesions

The mechanisms of high blood pressure (HBP) -related brain pathology progression remain relatively unclear. We investigated whether lowering BP in chronic HBP patients normalizes cerebral perfusion dynamics at resistance vessel and capillary levels. Sixty-seven patients with HBP and 49 age- and sex-matched healthy controls underwent simultaneous recordings of middle cerebral artery blood flow velocity (CBFV), BP, and end-tidal CO₂ concentration. Thirty-four controls and 28 patients underwent additional near-infrared spectroscopy recordings (oxygenated [O₂Hb] and deoxygenated [HHb] hemoglobin). Degree of microcirculatory white matter lesions was graded by Fazekas scale. Dynamic cerebral autoregulation (dCA) was assessed by transfer function analysis. BP was successfully lowered (patients = 89 ± 15 mm Hg, controls = 87 ± 17), but cerebrovascular resistance was higher in BP patients (p < 0.05). BP-CBFV phase was lower in very low frequency (VLF) (left/right: 48 ± 20°/44 ± 17; controls: 61 ± 20/60 ± 21; p < 0.001) and low frequency (LF) (34 ± 14/35 ± 14; controls: 48 ± 20/44 ± 17; p < 0.05) ranges. Gain was higher in VLF range (in %/ mm Hg 0.56 ± 0.44/0.59 ± 0.49; controls: 0.32 ± 0.29/0.34 ± 0.32; p ≤ 0.005). BP-CBFV phase and gain did not differ across Fazekas groups. Across all patients, the capillary phases and gains (CBFV-[O2Hb], CBFV-[HHb]) were comparable to controls. Successfully treated chronic HBP results in normal brain capillary hemodynamics while the resistance vessel state is disturbed (phase decrease, gain increase).

MRI Types of Cerebral Small Vessel Disease and Circulating Markers of Vascular Wall Damage

The evaluation of the clustering of magnetic resonance imaging (MRI) signs into MRI types and their relationship with circulating markers of vascular wall damage were performed in 96 patients with cerebral small vessel disease (cSVD) (31 men and 65 women; mean age, 60.91 ± 6.57 years). The serum concentrations of the tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor-A (VEGF-A), and hypoxia-inducible factor 1-α (HIF-1α) were investigated in 70 patients with Fazekas stages 2 and 3 of white matter hyperintensities (WMH) and 21 age- and sex-matched volunteers with normal brain MRI using ELISA. The cluster analysis excluded two patients from the further analysis due to restrictions in their scanning protocol. MRI signs of 94 patients were distributed into two clusters. In the first group there were 18 patients with Fazekas 3 stage WMH. The second group consisted of 76 patients with WMH of different stages. The uneven distribution of patients between clusters limited the subsequent steps of statistical analysis; therefore, a cluster comparison was performed in patients with Fazekas stage 3 WMH, designated as MRI type 1 and type 2 of Fazekas 3 stage. There were no differences in age, sex, degree of hypertension, or other risk factors. MRI type 1 had significantly more widespread WMH, lacunes in many areas, microbleeds, atrophy, severe cognitive and gait impairments, and was associated with downregulation of VEGF-A compared with MRI type 2. MRI type 2 had more severe deep WMH, lacunes in the white matter, no microbleeds or atrophy, and less severe clinical manifestations and was associated with upregulation of TNF-α compared with MRI type 1. The established differences reflect the pathogenetic heterogeneity of cSVD and explain the variations in the clinical manifestations observed in Fazekas stage 3 of this disease.

Incomplete recovery of cerebral blood flow dynamics in sufficiently treated high blood pressure

Objective:

Whether cerebrovascular regulation is different in patients with controlled high blood pressure (HBP) with and without small vessel disease (SVD).

Methods:

Sixty-seven healthy controls (mean age ± SD, 45 ± 16 years; 30 women, 37 men) and 40 patients (mean age, 64 ± 13 years; 14 women, 26 men) with HBP and different stages of SVD, underwent simultaneous recordings of the spontaneous fluctuations of BP, blood flow velocity (CBFV) in both middle cerebral arteries (MCA), and of end-tidal CO₂ (ETCO₂). Coherence and transfer function gain and phase between BP and CBFV were assessed in the frequency ranges of VLF (0.02–0.07 Hz), low frequency (0.07–0.15), and high frequency (>0.15). BP SD indicated BP variability (BPV).

Results:

In controls (BP, 86 ± 13 mmHg; ETCO₂, 39 ± 4 mmHg; BPV, 15 ± 6 mmHg), gain, phase and coherence were not age-dependent in simple or a multiple regression models. BPV correlated significantly in both MCAs with gain in low frequency and high frequency, and with phase in VLF and high frequency. In patients (BP, 91 ± 16 mmHg, ETCO₂, 39 ± 4 mmHg, BPV 18 ± 5 mmHg), only gain showed some differences between different SVD groups. Comparing all patients with 25 controls of similar age and sex, patients exhibited significantly (P < 0.05–P < 0.005): increased coherence and gain in VLF, decreased phase in VLF and low frequency, correlations between BPV with phase in low frequency (left) and with gain in VLF (left) and in high frequency (left and right).

Conclusion:

Phase seems an age independent autoregulatory index. In controlled HBP, CBF regulation is degraded at longlasting CBF changes; BPV effects lose their physiological bilateral distribution.

Tadalafil may improve cerebral perfusion in small-vessel occlusion stroke-a pilot study

New treatments for cerebral small-vessel disease are needed to reduce the risk of small-vessel occlusion stroke and vascular cognitive impairment. We investigated an approach targeted to the signalling molecule cyclic guanosine monophosphate, using the phosphodiesterase 5 inhibitor tadalafil, to explore if it improves cerebral blood flow and endothelial function in patients with cerebral small-vessel disease and stroke. In a randomized, double-blinded, placebo-controlled, cross-over pilot trial (NCT02801032), we included patients who had a previous (>6 months) small-vessel occlusion stroke. They received a single dose of either 20 mg tadalafil or placebo on 2 separate days at least 1 week apart. We measured the following: baseline MRI for lesion load, repeated measurements of blood flow velocity in the middle cerebral artery by transcranial Doppler, blood oxygen saturation in the cortical microvasculature by near-infrared spectroscopy, peripheral endothelial response by EndoPAT and endothelial-specific blood biomarkers. Twenty patients with cerebral small-vessel disease stroke (3 women, 17 men), mean age 67.1 ± 9.6, were included. The baseline mean values ± standard deviations were as follows: blood flow velocity in the middle cerebral artery, 57.4 ± 10.8 cm/s; blood oxygen saturation in the cortical microvasculature, 67.0 ± 8.2%; systolic blood pressure, 145.8 ± 19.5 mmHg; and diastolic blood pressure, 81.3 ± 9.1 mmHg. We found that tadalafil significantly increased blood oxygen saturation in the cortical microvasculature at 180 min post-administration with a mean difference of 1.57 ± 3.02%. However, we saw no significant differences in transcranial Doppler measurements over time. Tadalafil had no effects on peripheral endothelial function assessed by EndoPAT and endothelial biomarker results conflicted. Our findings suggest that tadalafil may improve vascular parameters in patients with cerebral small-vessel disease stroke, although the effect size was small. Increased oxygenation of cerebral microvasculature during tadalafil treatment indicated improved perfusion in the cerebral microvasculature, theoretically presenting an attractive new therapeutic target in cerebral small-vessel disease. Future studies of the effect of long-term tadalafil treatment on cerebrovascular reactivity and endothelial function are needed to evaluate general microvascular changes and effects in cerebral small-vessel disease and stroke.

Observer Agreement on Computed Tomography Perfusion Imaging in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Computed tomography (CT) perfusion (CTP) provides potentially valuable information to guide treatment decisions in acute stroke. Assessment of interobserver reliability of CTP has, however, been limited to small, mostly single center studies. We performed a large, internet-based study to assess observer reliability of CTP interpretation in acute stroke.

C9orf72 and intracerebral hemorrhage

The chromosome 9 open reading frame 72 (C9orf72) GGGGCC repeat expansion has been associated with several diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. It has also been associated with increased white matter changes in frontotemporal dementia and risk of cognitive impairment in ALS. Dementia is common both before and after intracerebral hemorrhage (ICH). Because the mechanisms of cognitive impairment in patients with ICH are uncertain, we investigated whether C9orf72 could influence dementia risk in this patient group. Therefore, we genotyped 1010 clinically characterized ICH cases and 2147 population controls in comparison with prior data of dementia and ALS cases. We did not find any association between C9orf72 repeat expansion and repeat size with ICH compared with controls or with dementia when assessing ICH patients only. The frequency of C9orf72 expansions in our series of individuals born in 1946 (2/2147) and other U.K. controls was age dependent, decreasing with increasing age, highlighting the high age-dependent penetrance of this expansion.

The effect of chronic cerebral hypoperfusion on the pathology of Alzheimer's disease: A positron emission tomography study in rats

Cerebrovascular disease is a potential risk factor for Alzheimer's disease (AD). Although acute cerebral hypoperfusion causes neuronal necrosis and infarction, chronic cerebral hypoperfusion induces apoptosis in neurons, but its effects on the cognitive impairment are not clear. The purpose of this study was to evaluate the effects of chronic cerebral hypoperfusion on AD pathology and cerebral glucose metabolism. A model of chronic cerebral hypoperfusion was established by ligating the common carotid arteries bilaterally in adult male rats (CAL group). Sham-operated rats underwent the same procedures without artery ligation (control group). At 12 weeks after ligation, expression levels of amyloid-β (Aβ) and hyperphosphorylated tau (p-tau), as well as the regional cerebral glucose metabolism, were evaluated using Western blots and positron emission tomography with fluorine-18 fluorodeoxyglucose, respectively. The expression levels of Aβ in the frontal cortex and hippocampus and of p-tau in the temporal cortex were significantly higher in the CAL group than those in the control group. The cerebral glucose metabolism of the amygdala, entorhinal cortex, and hippocampus was significantly decreased in the CAL group compared to that in the control. These results suggest that chronic cerebral hypoperfusion can induce AD pathology and may play a significant role in AD development.

Leukoaraiosis May Confound the Interpretation of CT Perfusion in Patients Treated with Mechanical Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Leukoaraiosis frequently coexists in patients with acute stroke. We studied whether leukoaraiosis could confound the interpretation of CTP findings in patients treated with mechanical thrombectomy.

MATERIALS AND METHODS

We analyzed 236 patients with stroke treated with mechanical thrombectomy and studied with CTP, of whom 127 (53.8%) achieved complete reperfusion. Periventricular white matter hyperintensities on MR imaging and hypodensities on NCCT were assessed through the Fazekas score. CTP-predicted nonviable tissue was defined as relative CBF <30%, and final infarct volume was quantified in DWI. We estimated mean MTT, CBV, and CBF in the asymptomatic hemisphere. In patients achieving complete reperfusion, we assessed the accuracy of nonviable tissue to predict final infarct volume using the intraclass correlation coefficient across periventricular hyperintensity/hypodensity Fazekas scores and variable relative CBF cutoffs.

RESULTS

MTT was longer (Spearman ρ = 0.279, P < .001) and CBF was lower (ρ = -0.263, P < .001) as the periventricular hyperintensity Fazekas score increased, while CBV was similar across groups (ρ = -0.043, P = .513). In the subgroup of patients achieving complete reperfusion, nonviable tissue-final infarct volume reliability was excellent in patients with periventricular hyperintensity Fazekas score grade 0 (intraclass correlation coefficient, 0.900; 95% CI, 0.805-0.950), fair in patients with periventricular hyperintensity Fazekas scores 1 (intraclass correlation coefficient, 0.569; 95% CI, 0.327-0.741) and 2 (intraclass correlation coefficient, 0.444; 95% CI, 0.165-0.657), and poor in patients with periventricular hyperintensity Fazekas score 3 (intraclass correlation coefficient, 0.310; 95% CI, -0.359-0.769). The most accurate cutoffs were relative CBF <30% for periventricular hyperintensity Fazekas score grades 0 and 1, relative CBF <25% for periventricular hyperintensity Fazekas score 2, and relative CBF <20% for periventricular hyperintensity Fazekas score 3. The reliability analysis according to periventricular hypodensity Fazekas score grades on NCCT was similar to that in follow-up MR imaging.

CONCLUSIONS

In patients with stroke, the presence of leukoaraiosis confounds the interpretation of CTP despite proper adjustment of CBF thresholds.

Exploring causal pathways linking cerebral small vessel diseases burden to poststroke depressive symptoms with structural equation model analysis

BACKGROUND

Cerebral small vessel diseases (SVD) are associated with poststroke depressive symptoms (PDS). The mechanisms underlying the association between SVD burden and PDS are unclear. This study investigated the clinical pathways linking SVD burden to PDS.

METHOD

A cohort of 563 patients with acute ischemic stroke were examined at three and fifteen months after stroke. PDS was measured with the 15-item Geriatric Depression Scale (GDS). Cognitive and physical functions were assessed with the Mini-Mental State Examination and the modified Rankin Scale, respectively. All patients received MRI scans at baseline. Infarct volumes and the four SVD markers (lacunae, white matter hyperintensities, cerebral microbleeds, and perivascular spaces) were assessed on magnetic resonance imaging. SVD burden was defined as a latent variable encompassing the information about all four SVD markers in structural equation modeling (SEM). SEM was further employed to examine the direct and indirect linking pathways between SVD burden, infarct volumes, stroke severity, poststroke cognitive and physical dysfunctions, and PDS.

RESULTS

The latent SVD burden was directly associated with more severe PDS at the 3-month follow-up (path coefficient=0.11), while SVD burden and PDS at the 15-month were mainly linked through PDS at the 3-month follow-up (path coefficient=0.48). The volume of acute infarcts and impaired physical functions predominantly mediated the association between SVD burden and PDS at 3-month follow-up. Physical and cognitive functions 15 months after stroke mainly bridged the link between SVD burden and the PDS at the 15-month follow-up.

LIMITATIONS

The study included patients with mild stroke, which reduced the generalizability of the findings.

CONCLUSIONS

SVD burden not only directly determines poststroke depressive symptoms, but also worsens acute stroke lesions, stroke severity, and poststroke neurological deficits, thereby contributing further to the development of PDS over the first 15 months after stroke.

Potential Applications of Remote Limb Ischemic Conditioning for Chronic Cerebral Circulation Insufficiency

Chronic cerebral circulation insufficiency (CCCI) refers to a chronic decrease in cerebral blood perfusion, which may lead to cognitive impairment, psychiatric disorders such as depression, and acute ischemic stroke. Remote limb ischemic conditioning (RLIC), in which the limbs are subjected to a series of transient ischemic attacks, can activate multiple endogenous protective mechanisms to attenuate fatal ischemic injury to distant organs due to acute ischemia, such as ischemic stroke. Recent studies have also reported that RLIC can alleviate dysfunction in distant organs caused by chronic, non-fatal reductions in blood supply (e.g., CCCI). Indeed, research has indicated that RLIC may exert neuroprotective effects against CCCI through a variety of potential mechanisms, including attenuated glutamate excitotoxicity, improved endothelial function, increased cerebral blood flow, regulation of autophagy and immune responses, suppression of apoptosis, the production of protective humoral factors, and attenuated accumulation of amyloid-β. Verification of these findings is necessary to improve prognosis and reduce the incidence of acute ischemic stroke/cognitive impairment in patients with CCCI.

Interarm Blood Pressure Difference has Various Associations with the Presence and Burden of Cerebral Small-Vessel Diseases in Noncardioembolic Stroke Patients

Background and Purpose

An interarm blood pressure difference (IABD) is independently related to the occurrence of cardiovascular disease and mortality. Cerebral small-vessel diseases (SVDs) are important risk factors for stroke, cognitive dysfunction, and mortality. We aimed to determine whether IABD is related to cerebral SVDs.

Methods

This study included 1,205 consecutive noncardioembolic ischemic stroke patients as confirmed by brain MRI and simultaneously measured the bilateral brachial blood pressures. We investigated cerebral SVDs based on high-grade white-matter hyperintensities (HWHs), presence of cerebral microbleeds (CMBs), high-grade perivascular spaces (HPVSs), and asymptomatic lacunar infarctions (ALIs) on brain MRI.

Results

In multivariate logistic regression, an interarm systolic blood pressure difference (IASBD) ≥10 mm Hg was independently related to the existence of HWHs [odds ratio (OR)=1.94, 95% CI=1.32–2.84, p=0.011] and had a tendency to be associated with the presence of HPVSs (OR=1.45, 95% CI=0.49–2.23, p=0.089) and ALIs (OR=1.42, 95% CI=0.96–2.11, p=0.052), but not with the presence of CMBs (OR=1.09, 95% CI=0.73–1.61, p=0.634). In multivariate linear regression adjusted for age, sex, and variables with p<0.1 in the univariate analysis, IASBD ≥10 mm Hg and interarm diastolic blood pressure difference ≥10 mm Hg were significantly correlated with an increased total burden of SVDs (β=0.080 and p=0.006, and β=0.065 and p=0.023, respectively).

Conclusions

This study found that IABD ≥10 mm Hg was associated with the presence and increased burden of cerebral SVDs in noncardioembolic stroke patients. This suggests that IABD ≥10 mm Hg could be a useful indicator of the presence and burden of cerebral SVDs in stroke patients.

Small Vessel Disease Is Associated with Tissue Inhibitor of Matrix Metalloproteinase-4 After Ischaemic Stroke

Small vessel disease (SVD) is frequent in aging and stroke patients. Inflammation and remodeling of extracellular matrix have been suggested as concurrent mechanisms of SVD. We investigated the relationship between imaging features of SVD and circulating metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in patients with ischaemic stroke. In patients treated with intravenous thrombolysis, we took blood samples before intravenous thrombolysis and 90 days after the acute stroke and analysed levels of MMPs and TIMPs. We assessed leukoaraiosis, number of lacunes and brain atrophy on pre-treatment CT scan and graded global SVD burden combining such features. We investigated associations between single features, global SVD and MMPs and TIMPs at baseline and at follow-up, retaining univariate statistically significant associations in multivariate linear regression analysis and adjusting for clinical confounders. A total of 255 patients [mean (±SD) = 68.6 (± 12.7) years, 154 (59%) males] were included, 107 (42%) had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. A total of 107 (42%) patients had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. After adjustment, only TIMP-4 proved associations with SVD features. Brain atrophy was associated with baseline TIMP-4 (β = 0.20;p = 0.019) and leukoaraiosis with 90 days TIMP-4 (β = 0.19; p = 0.013). Global SVD score was not associated with baseline TIMP-4 levels (β = 0.10; p = 0.072), whereas was associated with 90 days TIMP-4 levels (β = 0.21; p = 0.003). Total SVD burden was associated with higher TIMP-4 levels 90 days after stroke, whereas was not during the acute phase. Our results support a biological relationship between SVD grade and TIMP-4.

Relative Cerebral Blood Transit Time Decline and Neurological Improvement in Patients After Internal Carotid Artery Stenting

In this study we hypothesized that the alleviation of neurological symptoms long after internal carotid artery (ICA) stenting may be related to sustained improvement of cerebral perfusion. Thirty-four subjects (F/M; 15/19) with >70% stenosis of a single internal carotid artery and neurological symptoms, who underwent a carotid artery stenting procedure, were studied. Brain computed tomography perfusion (CTP) imaging was performed before and 3 years after ICA stenting. The following relative variables were compared: cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), time to peak (rTTP), and permeability surface area product (rPS). A survey also was conducted to compare the patients' clinical symptoms. Overall, we found that a trend toward rMTT decline was the only persisting change after ICA stenting. We then stratified the patients into the subgroups of <2%, 2-5%, and > 5% rMTT decline and found that those with a rMTT decline >2% reported a prominent reduction in subjective clinical symptoms such as headache, dizziness, tinnitus, blurred vision, transient blindness, a sense of gravity of the head, and pain in the eyeballs. We conclude that a shortened mean rMTT, likely reflecting improved cerebral microcirculation, underlies the improvement of neurological symptoms in patients with ICA stenosis.

Assessment of cerebrovascular reserve impairment using the breath-holding index in patients with leukoaraiosis

Many studies have demonstrated that leukoaraiosis is associated with impaired cerebrovascular reserve function. However, the definitive hemodynamic changes that occur in leukoaraiosis are not clear, and there are many controversies. This study aimed to investigate hemodynamic changes in symptomatic leukoaraiosis using transcranial Doppler ultrasonography and the breath-holding test in a Chinese Han population, from northern China. A total of 203 patients who were diagnosed with ischemic stroke or clinical chronic progressive ischemic symptoms were enrolled in this study, including 97 males and 106 females, with an age range of 43–93 years. The severity of leukoaraiosis was evaluated according to the Fazekas grading scale, and patients were divided into four groups accordingly. Grade 0 was no leukoaraiosis, and grades I, II, and III were mild, moderate, and severe leukoaraiosis, respectively, with 44, 79, 44, and 36 cases in each group. Transcranial Doppler ultrasonography and the breath-holding test were performed. The mean blood flow velocity of the bilateral middle cerebral artery was measured and the breath-holding index was calculated. The breath holding index was correlated with leukoaraiosis severity and cognitive impairment. Patients with a low breath holding index presented poor performance in the Montreal Cognitive Assessment (MoCA) and executive function tests. That is, the lower the breath holding index, the lower the scores for the MoCA and the higher for the trail-making test Parts A and B. These results indicate that the breath-holding index is a useful parameter for the evaluation of cerebrovascular reserve impairment in patients with leukoaraiosis. In addition, the breath-holding index can reflect cognitive dysfunction, providing a new insight into the pathophysiology of leukoaraiosis. This study was approved by the Ethics Committee of the Fifth People’s Hospital of Shenyang, China (approval No. 20160301) and registered in the Chinese Clinical Trial Registry (registration number: ChiCTR1800014421).

Small vessel disease and biomarkers of endothelial dysfunction after ischaemic stroke

Introduction

Although pathogenesis of small vessel disease is poorly understood, increasing evidence suggests that endothelial dysfunction may have a relevant role in development and progression of small vessel disease. In this cross-sectional study, we investigated the associations between imaging signs of small vessel disease and blood biomarkers of endothelial dysfunction at two different time points in a population of ischaemic stroke patients.

Patients and methods

In stroke patients treated with intravenous thrombolysis, we analysed blood levels of von Willebrand factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and vascular endothelial growth factor. Three reviewers independently assessed small vessel disease features using computed tomography. At baseline and 90 days after the index stroke, we tested the associations between single and combined small vessel disease features and levels of blood biomarkers using linear regression analysis adjusting for age, sex, hypertension, diabetes, smoke.

Results

A total of 263 patients were available for the analysis. Mean age (±SD) was 69 (±13) years, 154 (59%) patients were male. We did not find any relation between small vessel disease and endothelial dysfunction at baseline. At 90 days, leukoaraiosis was independently associated with intercellular adhesion molecule-1 (β = 0.21; p = 0.016) and vascular cell adhesion molecule-1 (β = 0.22; p = 0.009), and lacunes were associated with vascular endothelial growth factor levels (β = 0.21; p = 0.009) whereas global small vessel disease burden was associated with vascular endothelial growth factor (β = 0.26; p = 0.006).

Discussion

Leukoaraiosis and lacunes were associated with endothelial dysfunction, which could play a key role in pathogenesis of small vessel disease.

Conclusions

Small vessel disease features and total burden were associated with endothelial dysfunction 90 days after the stroke, whereas there was no relation during the acute phase. Our results suggest that endothelial dysfunction, particularly vascular endothelial growth factor, is involved in pathological process of small vessel disease.