A Non-linear Association Between Total Small Vessel Disease Score and Hemorrhagic Transformation After Ischemic Stroke With Atrial Fibrillation and/or Rheumatic Heart Disease

Brain Enlarged Perivascular Spaces as Imaging Biomarkers of Cerebrovascular Disease: A Clinical Narrative Review

Perivascular spaces or Virchow-Robin spaces form pathways along the subarachnoid spaces that facilitate the effective clearance of brain metabolic by-products through intracellular exchange and drainage of cerebrospinal fluid. Best seen on magnetic resonance imaging of the brain, enlarged perivascular spaces (EPVSs) are increasingly recognized as potential imaging biomarkers of neurological conditions. EPVSs are an established subtype of cerebral small-vessel disease; however, their associations with other cerebrovascular disorders are yet to be fully understood. In particular, there has been great interest in the association between the various parameters of EPVSs, such as number, size, and topography, and vascular neurological conditions. Studies have identified cross-sectional and longitudinal relationships between EPVS parameters and vascular events, such as ischemic stroke (both clinical and silent), intracerebral hemorrhage, vascular risk factors, such as age and hypertension, and neurodegenerative processes, such as vascular dementia and Alzheimer disease. However, these studies are limited by heterogeneity of data and the lack of consistent results across studied populations. Existing meta-analyses also fail to provide uniformity of results. We performed a qualitative narrative review with an aim to provide an overview of the associations between EPVSs and cerebrovascular diseases, which may help recognize gaps in our knowledge, inform the design of future studies, and advance the role of EPVSs as imaging biomarkers.

The association between the severity and distribution of white matter lesions and hemorrhagic transformation after ischemic stroke: A systematic review and meta-analysis

Background and purpose

As a part of the natural course of ischemic stroke, hemorrhagic transformation (HT) is a serious complication after reperfusion treatment, which may affect the prognosis of patients with ischemic stroke. White matter lesions (WMLs) refer to focal lesions on neuroimaging and have been suggested to indicate a high risk of HT. This systematic review and meta-analysis aimed to summarize current evidence on the relation between WML and HT.

Methods

This systematic review was prepared with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for publications on WML and HT in patients with ischemic stroke. Odds ratios (ORs) and 95% confidence intervals (CIs) from eligible studies were combined to quantify the association between the severity of WML and the risk of HT. In addition, the descriptive analysis was adopted to evaluate the influence of different WML distributions on predicting HT.

Results

A total of 2,303 articles were identified after removing duplicates through database searching, and 41 studies were included in our final analysis. The meta-analysis showed that the presence of WML was associated with HT (OR = 1.62, 95%CI 1.08-2.43, p = 0.019) and symptomatic intracerebral hemorrhage (sICH) (OR = 1.64, 95%CI 1.17-2.30, p = 0.004), and moderate-to-severe WML indicated a high risk of HT (OR = 2.03, 95%CI 1.33-3.12, p = 0.001) and sICH (OR = 1.92, 95%CI 1.31-2.81, p < 0.001). The dose-response meta-analysis revealed risk effects of increasing the severity of WML on both HT and ICH. In addition, both periventricular WML (PWML) (five of seven articles) and deep WML (DWML) (five of six articles) were shown to be associated with HT.

Conclusions

White matter lesions are associated with overall HT and sICH in patients with ischemic stroke, and more severe WMLs indicate a high risk of HT and sICH. In addition, both PWML and DWMLs could be risk factors for HT.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: PROSPERO CRD42022313467.

Association between Deep Medullary Veins in the Unaffected Hemisphere and Functional Outcome in Acute Cardioembolic Stroke: An Observational Retrospective Study

Objective: To explore whether deep medullary veins (DMVs) in the unaffected hemisphere were associated with functional outcome in acute cardioembolic stroke patients. Methods: Acute cardioembolic stroke patients at a single center were retrospectively included. DMVs visibility in the unaffected hemisphere was assessed using a well-established four-grade scoring method based on susceptibility-weighted imaging (SWI): grades 0−3 (grade 0 for no visible DMVs; grade 1 for the numbers of conspicuous DMVs < 5; grade 2 for numbers raging from 5 to 10; grade 3 for more than 10). Patients were further divided into mild-to-moderate (grade 0−2) and severe DMVs (grade 3) groups. Functional outcomes were evaluated using the modified Rankin scale (mRS) score at three months. Poor outcome was defined as mRS ≥ 3. Binary logistic regression analysis was used to explore the association between DMVs grade and functional outcome. Results: A total of 170 patients were finally included. Compared with the mild-to-moderate DMVs group (149 patients), the severe DMVs group (21 patients) had higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (p = 0.002), lower levels of admission systolic blood pressure (BP) (p = 0.031), and elevated rates of large infarction (p = 0.003). At three months, the severe DMVs group had higher mRS (p = 0.002). Patients in the poor outcome group (82/170, 48.2%) had older age, higher baseline NIHSS score, lower admission diastolic BP, higher rates of hemorrhagic transformation and large infarction, and an increased proportion of severe DMVs (all p < 0.05). After adjusting for confounders, multivariable regression analysis showed that the severe DMVs grade (adjusted odds ratio [OR] = 5.830, 95% confidence interval [CI] = 1.266−26.856, p = 0.024) was significantly associated with three-month functional outcomes without interaction with other potential risk factors (p for interaction > 0.05). Conclusions: DMVs grade in the unaffected hemisphere was independently associated with three-month functional outcome in acute cardioembolic stroke patients. Patients with severe DMVs were more likely to have a poor functional outcome at three months.

Enlarged perivascular spaces and hemorrhagic transformation after acute ischemic stroke

Background

Enlarged perivascular spaces (EPVS) are considered to be neuroimaging markers of cerebral small vessel disease (CSVD). It remains unknown whether EPVS are associated with hemorrhagic transformation (HT) after acute ischemic stroke (AIS). We performed this retrospective cohort study to explore the associations of EPVS with clinical risk factors and other CSVD imaging features, and to investigate the relationship between EPVS and HT in patients with AIS.

Methods

AIS patients admitted within 24 hours of stroke onset between January 2016 and December 2017 were consecutively enrolled. EPVS, lacunes, and white matter hyperintensities (WMH) were rated with validated rating scales on magnetic resonance images after the stroke. HT was defined as hemorrhage determined by follow-up brain imaging during the patients' hospital stay. Logistic regression was used to determine the risk factors and associations with other CSVD markers of EPVS in the basal ganglia (BG) and centrum semiovale (CS) regions, and the impact of EPVS on HT was further explored.

Results

Among 494 included patients (mean age 66.4 years, 58.1% male), 81 (16.4%) experienced HT. In the multivariate logistic analyses, increasing age [odd ratio (OR) 1.041, 95% confidence interval (CI), 1.017-1.066], hypertension (OR 2.174, 95% CI, 1.338-3.532), lacunar stroke (OR 1.968, 95% CI, 1.169-3.314), CS-EPVS (OR 2.474, 95% CI, 1.796-3.407), and periventricular WMH (OR 2.140, 95% CI, 1.441-3.176) were significantly associated with BG-EPVS; whereas only BG-EPVS (OR 4.349, 95% CI, 2.281-8.291) were independently related to CS-EPVS. After adjustment for potential variables, neither BG-EPVS (OR 0.674, 95% CI, 0.336-1.350) nor CS-EPVS (OR 0.792, 95% CI, 0.334-1.879) was significantly associated with the occurrence of HT.

Conclusions

Our data showed that EPVS in the BG and CS regions were interrelated and had different risk factors in ischemic stroke patients. EPVS (particularly that in BG) were independently related to other CSVD markers. The presence or burden of EPVS was not significantly associated with HT after AIS.

Extent of white matter lesion is associated with early hemorrhagic transformation in acute ischemic stroke related to atrial fibrillation

BACKGROUND

Hemorrhagic transformation (HT) after stroke, related to atrial fibrillation (AF), is a frequent complication, and it can be associated with a delay in the (re-)initiation of oral anticoagulation therapy. We investigated the effect of the presence and severity of white matter disease (WMD) on early HT after stroke related to AF.

METHODS

A consecutive series of patients with recent (<4 weeks) ischemic stroke and AF, treated at the Hyper Acute Stroke Unit of the Imperial College London between 2010 and 2017, were enrolled. Patients with brain MRI performed 24-72 h from stroke onset and not yet started on anticoagulant treatment were included. WMD was graded using the Fazekas score.

RESULTS

Among the 441 patients eligible for the analysis, 91 (20.6%) had any HT. Patients with and without HT showed similar clinical characteristics. Patients with HT had a larger diffusion-weighted imaging (DWI) infarct volume compared to patients without HT (p < .001) and significant difference in the distribution of the Fazekas score (p = .001). On multivariable analysis, HT was independently associated with increasing DWI infarct volume (odd ratio (OR), 1.03; 95% confidence interval (CI), 1.01-1.05; p < .001), higher Fazekas scores (OR, 1.94; 95% CI, 1.47-2.57; p < .001) and history of previous intracranial hemorrhage (OR, 4.80; 95% CI, 1.11-20.80; p = .036).

CONCLUSIONS

Presence and severity of WMD is associated with increased risk of development of early HT in patients with stroke and AF. Further evidence is needed to provide reliable radiological predictors of the risk of HT in cardioembolic stroke.