Preexisting Cerebral Microbleeds on Susceptibility-Weighted Magnetic Resonance Imaging and Post-Thrombolysis Bleeding Risk in 392 Patients

Prevalence and Risk Factors of Cerebral Microbleeds among Egyptian Patients with Acute Ischemic Stroke

BACKGROUND

Cerebral microbleeds (CMBs) are markers of underlying hemorrhage-prone cerebral small vessel disease detected on MRI. They are associated with a heightened risk of stroke and cognitive decline. The prevalence of CMBs among Egyptian patients with ischemic stroke is not well studied. Our aim was to detect the prevalence of CMBs and associated risk factors among Egyptian patients with ischemic stroke.

METHODS

A prospective, cross-sectional, single-center study of consecutive patients with ischemic stroke. Patients were recruited between January 2021 and January 2022 at the Assiut University Hospital in the south of Egypt. Patients with known bleeding diathesis were excluded. All participants underwent full neurological assessment, urgent laboratory investigations, and MRI with T2* sequence.

RESULTS

The study included 404 patients, 191 (47.3%) of them were females. The mean age of the study population was 61 ± 1 years, and the mean NIHSS on admission was 12 ± 5. The prevalence of CMB was 26.5%, of whom 6.5% were young adults (age ≤45 years). CMBs were detected in 34.6% of patients with stroke caused by large artery atherosclerosis, 28.0% with small vessel disease stroke subtype, 25.2% with stroke of undetermined cause, and in 12.1% with cardioembolic stroke. History of AF, hypertension, dyslipidemia, Fazekas score >2, dual antiplatelet use, combined antiplatelet with anticoagulant treatment, and thrombolytic therapy remained independently associated with CMBs following multivariable regression analyses.

CONCLUSION

The high number of identified CMBs needs to inform subsequent therapeutic management of these patients. We are unable to determine whether the association between CMBs and antithrombotic use is a causal relationship or rather confounded by indication for these treatments in our observational study. To understand more about the underlying cause of this finding, more studies are needed.

Intracranial hemorrhage risk in patients with cerebral microbleeds after mechanical thrombectomy for acute ischemic stroke: a systematic review and meta-analysis

Background and purpose intracranial hemorrhage risk in patients with cerebral microbleeds (CMBs) after mechanical thrombectomy for acute ischemic stroke (AIS) was investigated. We searched PubMed and Embase from inception to 29 August 2023 for relevant studies, calculated pooled odds ratio (ORs) of intracerebral hemorrhage (ICH) subtypes in AIS patients with CMB presence, 1-4 or ≥ 5 CMBs versus CMB absence, and with different CMB locations after mechanical thrombectomy. ICH subtypes included any ICH, symptomatic and asymptomatic ICH, hemorrhage outside infarct (including subarachnoid hemorrhage), hemorrhagic infarction, and parenchymal hemorrhage after mechanical thrombectomy. Five eligible studies enrolling 2051 patients were included. No significant association was shown between CMB locations (lobar, deep, infratentorial or mixed) and ICH risk. CMB presence or 1-4 CMBs did not significantly increase the risk of any ICH, symptomatic or asymptomatic ICH, ICH outside infarct, subarachnoid hemorrhage, hemorrhagic infarction, or parenchymal hemorrhage. CMBs ≥ 5 increased the risk of any ICH (OR 2.58, 95% CI 1.16-5.72), parenchymal hemorrhage (OR 3.38, 95% CI 1.43-7.97) and parenchymal hemorrhage-2 (OR 5.33, 2.05-13.86), without increasing hemorrhagic infarction or parenchymal haemorrhage-1 risk. After adjusted for possible confounding factors, increases in CMB burden were associated with hemorrhagic complications but not with symptomatic ICH. In AIS patients who received mechanical thrombectomy, no association was shown between CMB location and ICH risk. ICH risk was not significantly increased by CMB presence or 1-4 CMBs. ICH risk in patients with ≥ 5 CMBs requires further study.

Clinical significance of the Microbleed Anatomical Rating Scale score in ischemic stroke patients treated with intravenous thrombolysis

BACKGROUND

Conflicting results were shown on the relationship between cerebral microbleeds (CMBs) burden and functional outcomes in patients treated with intravenous tissues plasminogen activator (IV tPA). We aimed to investigate the relationship between CMBs burden and functional outcomes using the Microbleed Anatomical Rating Scale (MARS) and determine its optimal cutoff value.

METHODS

A retrospective study was conducted to include patients treated with IV tPA in our stroke center, and the MARS was used to assess the CMBs burden. Other clinical data including demographic factors, stroke severity, vascular risk factors, and clinical outcomes were also documented. Another mediation analysis was performed to investigate whether early neurological improvement could mediate the association between MARS and functional outcomes.

RESULTS

A total of 408 patients were included. A cutoff value of 1.5 could predict functional outcomes in patients treated with IV tPA. Based on that cutoff value, MARS showed an independent relationship with functional outcomes [adjusted OR (Odds Ratio) 0.841, 95% confidence interval (CI) 0.720-0.982, P = .029]. A shift analysis showed that higher MARS score (MARS ≥1.5) was related with poor functional outcome according to mRS score distribution (OR = 0.519, 95% CI 0.336-0.803, P = .003). Total effect (indirect + direct effect) was calculated and showed in figure. Early neurological improvement mediated 24% of the effect of MARS score on functional outcomes.

CONCLUSION

Our study showed that MARS could be a potential method to assess the functional outcome based on CMBs in patients treated with IV tPA, and MARS score ≥ 1.5 might be an optimal threshold for poor functional outcome.

Prevalence and Impact of Cerebral Microbleeds on Clinical and Safety Outcomes in Acute Ischaemic Stroke Patients Receiving Reperfusion Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Cerebral microbleeds (CMBs), a notable neuroimaging finding often associated with cerebral microangiopathy, demonstrate a heightened prevalence in patients diagnosed with acute ischemic stroke (AIS), which is in turn linked to less favourable clinical prognoses. Nevertheless, the exact prevalence of CMBs and their influence on post-reperfusion therapy outcomes remain inadequately elucidated.

MATERIALS AND METHODS

Through systematic searches of PubMed, Embase and Cochrane databases, studies were identified adhering to specific inclusion criteria: (a) AIS patients, (b) age ≥ 18 years, (c) CMBs at baseline, (d) availability of comparative data between CMB-positive and CMB-negative groups, along with relevant post-reperfusion therapy outcomes. The data extracted were analysed using forest plots of odds ratios, and random-effects modelling was applied to investigate the association between CMBs and symptomatic intracerebral haemorrhage (sICH), haemorrhagic transformation (HT), 90-day functional outcomes, and 90-day mortality post-reperfusion therapy.

RESULTS

In a total cohort of 9776 AIS patients who underwent reperfusion therapy, 1709 had CMBs, with a pooled prevalence of 19% (ES 0.19; 95% CI: 0.16, 0.23, p < 0.001). CMBs significantly increased the odds of sICH (OR 2.57; 95% CI: 1.72; 3.83; p < 0.0001), HT (OR 1.53; 95% CI: 1.25; 1.88; p < 0.0001), as well as poor functional outcomes at 90 days (OR 1.59; 95% CI: 1.34; 1.89; p < 0.0001) and 90-day mortality (OR 1.65; 95% CI: 1.27; 2.16; p < 0.0001), relative to those without CMBs, in AIS patients undergoing reperfusion therapy (encompassing intravenous thrombolysis [IVT], endovascular thrombectomy [EVT], either IVT or EVT, and bridging therapy). Variations in the level of association can be observed among different subgroups of reperfusion therapy.

CONCLUSIONS

This meta-analysis underscores a significant association between CMBs and adverse postprocedural safety outcomes encompassing sICH, HT, poor functional outcome, and increased mortality in AIS patients undergoing reperfusion therapy. The notable prevalence of CMBs in both the overall AIS population and those undergoing reperfusion therapy emphasizes their importance in post-stroke prognostication.

Impact of pre-treatment cerebral microbleeds on the outcomes of endovascular thrombectomy: A systematic review and meta-analysis

OBJECTIVE/AIM

To investigate the effect of cerebral microbleeds (CMBs) on the functional and safety outcomes of endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO).

METHODS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines for systematic review and meta-analysis. We included observational studies that recruited AIS-LVO patients, used susceptibility-sensitive magnetic resonance imaging (MRI) to detect CMBs, and examined the association between them and predefined outcome events. The extracted data included study and population characteristics, risk of bias domains, and outcome measures. The outcomes of interest included functional independence, revascularization success, procedural and hemorrhagic adverse events. We conducted a meta-analysis using the Mantel-Haenszel method and calculated the risk ratios.

RESULTS

Four studies with a total of 1,514 patients were included. A significant reduction in the likelihood of achieving a favorable functional outcome was observed in patients with CMBs (Risk ratio (RR) 0.69, 95% confidence interval (CI): 0.52 to 0.91, P=0.01). No significant differences were observed between the CMBs and no CMBs groups in terms of successful revascularization, mortality, intracranial hemorrhage (ICH), subarachnoid hemorrhage (SAH), and parenchymal hematoma.

CONCLUSIONS

The presence of CMBs significantly reduced the likelihood of achieving functional independence post-EVT in AIS-LVO patients. However, CMBs did not impact the rates of successful revascularization, mortality, or the occurrence of various hemorrhagic events. Future research should explore the mechanisms of this association and strategies to mitigate its impact.

Brain hemorrhage on 24h-CT and functional outcome in stroke patients with cerebral amyloid angiopathy features on pre-thrombolysis MRI treated with intravenous thrombolysis: A case series

BACKGROUND AND OBJECTIVES

In stroke patients treated with intravenous thrombolysis (IVT), presence and high number of strictly lobar cerebral microbleeds (compatible with cerebral amyloid angiopathy, CAA) seems to be associated with increased risk of hemorrhagic transformation, symptomatic hemorrhagic transformation, remote hemorrhage, and poor functional outcome. Some of these CAA patients with cerebral microbleeds also have chronic lobar intracerebral hemorrhage. Few data are available on IVT-treated CAA patients showing cortical superficial siderosis. There are no reports studying factors associated with brain hemorrhagic complication or functional outcome in IVT-treated CAA patients. We present a case series study of IVT-treated stroke patients with CAA features on pre-IVT MRI in whom we have evaluated brain hemorrhagic complications on 24 h-CT and functional outcome after IVT.

MATERIAL AND METHODS

In our stroke center, IVT decision in patients with CAA MRI features is at the physician's discretion. We retrospectively screened our stroke database between January 2015 and July 2022 for pre-IVT imaging of 959 consecutive IVT-treated stroke patients without ongoing anticoagulation therapy for probable CAA MRI features defined by modified Boston criteria. After exclusion of 119 patients with missing MRI (n = 47), MRI showing motion artefacts (n = 49) or with alternative chronic brain hemorrhage cause on MRI (n = 23), 15 IVT-treated patients with probable CAA on pre-IVT MRI were identified. In these 15 patients, clinical, biological and MRI characteristics were compared between patients with vs. without post-IVT hemorrhage and between patients with poor (MRS 3-6) vs. good (MRS 0-2) functional outcome at discharge.

RESULTS

Two patients showed brain hemorrhage on 24 h-CT and both died after 40 and 31 days respectively. The remaining patients had no brain hemorrhage and showed very good outcome except one. Atrial fibrillation (p = 0.029) and Fazekas scale (p = 0.029) were associated with brain hemorrhage whereas atrial fibrillation (p = 0.0022), NIHSS (p = 0.027), blood glucose level (p = 0.024), CRP (p = 0.022) and DWI ASPECT (p = 0.016) were associated with poor outcome.

DISCUSSION

Consequences of IVT in CAA patients can be dramatic. Larger studies are needed to compare IVT risks and outcome between CAA and non-CAA patients, also including CAA patients with chronic intracerebral hemorrhage or cortical superficial siderosis. In addition, future studies should try to identify clinical, biological and radiological features at high risk for brain hemorrhage and poor outcome in order to assess the risk-benefit ratio for IVT in CAA.

CLINICAL TRIAL REGISTRATION-URL

http://www.

CLINICALTRIALS

gov. Unique identifier: NCT05565144.

Exploring the Impact of Cerebral Microbleeds on Stroke Management

Stroke constitutes a major cause of functional disability and mortality, with increasing prevalence. Thus, the timely and accurate prognosis of stroke outcomes based on clinical or radiological markers is vital for both physicians and stroke survivors. Among radiological markers, cerebral microbleeds (CMBs) constitute markers of blood leakage from pathologically fragile small vessels. In the present review, we evaluated whether CMBs affect ischemic and hemorrhagic stroke outcomes and explored the fundamental question of whether CMBs may shift the risk-benefit balance away from reperfusion therapy or antithrombotic use in acute ischemic stroke patients. A literature review of two databases (MEDLINE and Scopus) was conducted to identify all the relevant studies published between 1 January 2012 and 9 November 2022. Only full-text articles published in the English language were included. Forty-one articles were traced and included in the present review. Our findings highlight the utility of CMB assessments, not only in the prognostication of hemorrhagic complications of reperfusion therapy, but also in forecasting hemorrhagic and ischemic stroke patients' functional outcomes, thus indicating that a biomarker-based approach may aid in the provision of counseling for patients and families, improve the selection of more appropriate medical therapies, and contribute to a more accurate choice of patients for reperfusion therapy.

Small vessel disease burden may not portend unfavorable outcome after thrombectomy for acute large vessel occlusion

OBJECTIVES

We aimed to investigate the correlation between an overall cerebral small vessel disease (CSVD) burden and outcomes after endovascular treatment (EVT) for patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO).

METHODS

In a multicenter registry study, we enrolled patients with EVT for anterior-circulation LVO-stroke. In 3.0-T MR imaging, we assessed 4 CSVD imaging markers, lacunes, white matter hyperintensities, cerebral microbleeds, and enlarged perivascular spaces, each assigned a score of 0 or 1 and summed up to an overall CSVD burden score of 0-4. We dichotomized the overall CSVD severity as none to mild (score 0-2) and moderate to severe (3-4). Primary outcome was 90-day functional dependence or death (modified Rankin Scale (mRS) 3-6). Secondary outcomes included increase in NIH Stroke Scale ≥ 4 within 24 h (early neurological deterioration (END)) and within 7 days, symptomatic intracranial hemorrhage, 90-day mRS 2-6, and 90-day mortality.

RESULTS

Among 311 patients (63.0% male; mean age 65.1 ± 12.7 years), 260 (83.6%) had none-to-mild and 51 (16.4%) had moderate-to-severe overall CSVD burden. Moderate-to-severe CSVD burden was not significantly associated with the primary outcome (47.1% versus 45.4%; p > 0.05 in univariate and multivariate logistic regression), or the secondary outcomes except for a higher risk of END (11.8% versus 3.1%; p < 0.05 in multivariate analyses). Sensitivity analyses with 0-1 versus 2-4 of the CSVD burden score, and the score as an ordinal variable, showed similar results.

CONCLUSIONS

An overall moderate-to-severe CSVD burden was not associated with 90-day functional dependence or death, after EVT for anterior-circulation LVO.

TRIAL REGISTRATION

ChiCTR1900022154 KEY POINTS: • Moderate-to-severe cerebral small vessel disease burden on MRI should not be an exclusion indicator in determining the eligibility of an acute ischemic stroke patient for endovascular treatment.

Influence of cerebral microbleeds on mechanical thrombectomy outcomes

In ischemic stroke patients undergoing endovascular treatment (EVT), we aimed to test the hypothesis that cerebral microbleeds (CMBs) are associated with clinical outcomes, while estimating the mediating effects of hemorrhagic transformation (HT), small-vessel disease burden (white matter hyperintensities, WMH), and procedural success. From a multicenter EVT registry, patients who underwent pretreatment MR imaging were analyzed. They were trichotomized according to presence of CMBs (none vs. 1–4 vs. ≥ 5). The association between CMB burden and 3-month mRS was evaluated using multivariable ordinal logistic regression, and mediation analyses were conducted to estimate percent mediation. Of 577 patients, CMBs were present in 91 (15.8%); 67 (11.6%) had 1–4 CMBs, and 24 (4.2%) had ≥ 5. Increases in CMBs were associated with hemorrhagic complications (β = 0.27 [0.06–0.047], p = 0.010) in multivariable analysis. The CMB effect on outcome was partially mediated by post-procedural HT degree (percent mediation, 14% [0–42]), WMH (23% [7–57]) and lower rates of successful reperfusion (6% [0–25]). In conclusion, the influence of CMBs on clinical outcomes is mediated by small-vessel disease burden, post-procedural HT, and lower reperfusion rates, listed in order of percent mediation size.

Susceptibility-weighted Imaging in Neuroradiology: Practical Imaging Principles, Pearls and Pitfalls

Susceptibility-weighted imaging (SWI) was one of the recent and helpful advancement in magnetic resonance imaging. Its utilization -provided valuable information for the radiologists in multiple fields, including neuroradiology. SWI was able to demonstrate cerebral paramagnetic and diamagnetic substances. Therefore, the applications of this imaging technique were diverse in research and clinical neuroradiology. This article reviewed the basic technical steps, various clinical applications of SWI, and potential limitations. The practicing radiologist needs to be oriented about using SWI and phase images in the right- and left-handed MRI systems to demonstrate different brain pathologies, including neurovascular diseases, traumatic brain injuries, brain tumors, infectious and inflammatory, and neurodegenerative diseases.

Small Vessel Disease Burden and Outcomes of Mechanical Thrombectomy in Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: Cerebral small vessel disease (SVD) is prevalent in the population, especially among elderly individuals. Substantial uncertainties remain about the clinical relevance of SVD with outcomes of mechanical thrombectomy (MT) in acute ischemic stroke (AIS).

Objectives: This systematic review and meta-analysis was performed to evaluate the association between SVD and clinical outcomes in patients with AIS undergoing MT.

Methods: We systematically searched the Medline, Embase, and Cochrane databases for relevant clinical studies. The exposure of SVD mainly included leukoaraiosis, cerebral microbleeds (CMBs), and lacunes. The pooled OR was used to calculate the association between each subtype of SVD and outcomes of MT. The primary outcome was poor functional outcome, which was defined as a modified Rankin Scale score (mRS) ≥3 at 90 days after MT. The secondary outcomes included mortality at 90 days, in-hospital mortality, intracranial hemorrhage (ICH) and symptomatic intracranial hemorrhage (sICH), successful recanalization and futile recanalization (FR), early neurological improvement, and early neurological deterioration (END) after MT.

Results: Overall, 20 studies with 5,189 patients with AIS undergoing MT were included. High leukoaraiosis burden (HLB) at baseline was associated with increased risks of poor functional outcome at 90 days (OR 2.70, 95% CI 2.01–3.63; p < 0.001; 10 studies; n = 2,004), in-hospital mortality (OR 4.06, 95% CI 1.48–11.13; p = 0.006; 2 studies; n = 314), FR (OR 5.00, 95% CI 2.86–8.73; p < 0.001; 3 studies; n = 493), and END (OR 2.65, 95% CI 1.09–6.45; 1 study; n = 273) after MT. HLB (VSS 3–4 or FS ≥ 2) at baseline was not associated with mortality at 90 days, ICH, or sICH after MT. CMBs at baseline were found to be associated with increased risks of poor functional outcome at 90 days (OR 1.84, 95% CI 1.17–2.90; p = 0.008; 2 studies; n = 1,924) after MT. We found no association between the presence of lacunes and poor functional outcome at 90 days after MT.

Conclusions: In patients with AIS undergoing MT, HLB and CMBs were associated with increased risks of unfavorable outcomes after MT.

Cerebral microbleeds and stroke risk after ischaemic stroke or transient ischaemic attack: a pooled analysis of individual patient data from cohort studies

BACKGROUND

Cerebral microbleeds are a neuroimaging biomarker of stroke risk. A crucial clinical question is whether cerebral microbleeds indicate patients with recent ischaemic stroke or transient ischaemic attack in whom the rate of future intracranial haemorrhage is likely to exceed that of recurrent ischaemic stroke when treated with antithrombotic drugs. We therefore aimed to establish whether a large burden of cerebral microbleeds or particular anatomical patterns of cerebral microbleeds can identify ischaemic stroke or transient ischaemic attack patients at higher absolute risk of intracranial haemorrhage than ischaemic stroke.

METHODS

We did a pooled analysis of individual patient data from cohort studies in adults with recent ischaemic stroke or transient ischaemic attack. Cohorts were eligible for inclusion if they prospectively recruited adult participants with ischaemic stroke or transient ischaemic attack; included at least 50 participants; collected data on stroke events over at least 3 months follow-up; used an appropriate MRI sequence that is sensitive to magnetic susceptibility; and documented the number and anatomical distribution of cerebral microbleeds reliably using consensus criteria and validated scales. Our prespecified primary outcomes were a composite of any symptomatic intracranial haemorrhage or ischaemic stroke, symptomatic intracranial haemorrhage, and symptomatic ischaemic stroke. We registered this study with the PROSPERO international prospective register of systematic reviews, number CRD42016036602.

FINDINGS

Between Jan 1, 1996, and Dec 1, 2018, we identified 344 studies. After exclusions for ineligibility or declined requests for inclusion, 20 322 patients from 38 cohorts (over 35 225 patient-years of follow-up; median 1·34 years [IQR 0·19-2·44]) were included in our analyses. The adjusted hazard ratio [aHR] comparing patients with cerebral microbleeds to those without was 1·35 (95% CI 1·20-1·50) for the composite outcome of intracranial haemorrhage and ischaemic stroke; 2·45 (1·82-3·29) for intracranial haemorrhage and 1·23 (1·08-1·40) for ischaemic stroke. The aHR increased with increasing cerebral microbleed burden for intracranial haemorrhage but this effect was less marked for ischaemic stroke (for five or more cerebral microbleeds, aHR 4·55 [95% CI 3·08-6·72] for intracranial haemorrhage vs 1·47 [1·19-1·80] for ischaemic stroke; for ten or more cerebral microbleeds, aHR 5·52 [3·36-9·05] vs 1·43 [1·07-1·91]; and for ≥20 cerebral microbleeds, aHR 8·61 [4·69-15·81] vs 1·86 [1·23-1·82]). However, irrespective of cerebral microbleed anatomical distribution or burden, the rate of ischaemic stroke exceeded that of intracranial haemorrhage (for ten or more cerebral microbleeds, 64 ischaemic strokes [95% CI 48-84] per 1000 patient-years vs 27 intracranial haemorrhages [17-41] per 1000 patient-years; and for ≥20 cerebral microbleeds, 73 ischaemic strokes [46-108] per 1000 patient-years vs 39 intracranial haemorrhages [21-67] per 1000 patient-years).

INTERPRETATION

In patients with recent ischaemic stroke or transient ischaemic attack, cerebral microbleeds are associated with a greater relative hazard (aHR) for subsequent intracranial haemorrhage than for ischaemic stroke, but the absolute risk of ischaemic stroke is higher than that of intracranial haemorrhage, regardless of cerebral microbleed presence, antomical distribution, or burden.

FUNDING

British Heart Foundation and UK Stroke Association.

Synergistic role of susceptibility-weighted imaging with diffusion-weighted imaging and magnetic resonance angiography in the evaluation of acute arterial stroke

Objective

This study was performed to investigate whether diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) are more effective than conventional imaging modalities for evaluation of stroke and selection of candidates for thrombolytic therapy.

Methods

Eighty patients who presented within 12 hours of onset of symptoms of brain ischemia underwent 1.5T magnetic resonance imaging. DWI and SWI were compared with conventional sequences (T1, T2, and fluid-attenuated inversion recovery [FLAIR]) and time-of-flight magnetic resonance angiography (TOF-MRA) to assess factors that affect stroke management and prognosis.

Results

The volume of brain tissue showing hyperintensity was significantly greater than that showing diffusion restriction in patients with a >6-hour symptom onset. The hypointensity sign (susceptibility sign) on SWI showed a sensitivity of 66.7%, specificity of 87.5%, positive predictive value of 88.9, and negative predictive value of 63.6 compared with TOF-MRA. Micro-hemorrhagic foci were significantly associated with 27-mL infarcts on DWI (sensitivity, 71.4%; specificity, 85.0%). Patients with DWI–SWI mismatch showed better responses to thrombolytics. FLAIR–DWI mismatch helped to assess the time of stroke onset.

Conclusion

DWI and SWI should be part of the routine imaging protocol in patients with acute stroke and serve as a decision-making tool for selection of patients for thrombolytic therapy.

Pre-treatment cerebral microbleeds and intracranial hemorrhage in patients with ischemic stroke receiving endovascular therapy: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Predicting the risk of intracranial hemorrhage (ICH) is an important aspect for improving the efficacy and safety of endovascular therapy (EVT). We intended to perform a systematic review and meta-analysis to show whether pre-treatment cerebral microbleeds (CMBs) were associated with an increased incidence of ICH in patients with ischemic stroke receiving EVT.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Library from their dates of inception to December 18, 2018, and also manually searched reference lists of relevant articles. Cumulative prevalence of CMBs and ICH was calculated. Relative risk and 95% confidence interval (CI) were calculated for the incidence of ICH in patients with CMBs versus those without after EVT.

RESULTS

Four studies involving 598 patients were included. The pooled prevalence of CMBs was 18% (95% CI 15-21%) and the pooled prevalence of ≥ 5 CMBs was 1% (95% CI 0-2%). The pooled incidence of ICH was 29% (95% CI 8-49%) in all patients, 25% (95% CI 5-45%) in those with CMBs and 29% (95% CI 8-50%) in those without CMBs. The pooled relative risk of ICH was 0.90 (95% CI 0.65-1.25, P = 0.528; I² = 0%, P = 0.949) in patients with CMBs versus those without CMBs.

CONCLUSIONS

There is no evidence that pre-treatment CMBs were associated with an increased incidence of ICH in patients with ischemic stroke receiving EVT.

Impact of Microbleeds on Outcome Following Recanalization in Patients With Acute Ischemic Stroke

Background and Purpose- We analyzed the association between cerebral microbleeds (CMBs) and clinical outcome in acute ischemic stroke patients and especially in a subgroup of patients with successful recanalization. Methods- A total of 1532 acute ischemic stroke patients treated with intravenous thrombolysis or mechanical thrombectomy were enrolled in this prospective cohort study. The primary outcome was measured using the modified Rankin Scale at 3 months, according to the CMB status based on magnetic resonance imaging at admission. Favorable outcome was defined as functional independence with modified Rankin Scale scores of 0 to 2. Secondary outcomes included the occurrence of symptomatic intracranial hemorrhage. Results- There was no statistically significant association between the presence of CMB and favorable outcome at 3 months when considering all patients (44.3% versus 37.6%; P=0.121). In patients with recanalization, the number of patients with favorable outcomes was significantly higher in the CMB-negative than in the CMB-positive group (57.0% versus 36.0%; P<0.001). In the final multivariate analysis, the presence of CMB, and in particular high CMB burden (≥5), and lobar location, were significantly associated with less favorable 3-month outcomes (odds ratio=0.57; 95% CI, 0.33-0.97; P=0.038) and symptomatic intracranial hemorrhage (odds ratio=3.21; 95% CI, 1.37-7.49; P=0.007) in patients with recanalization. In the analysis of subgroups, a statistically significant interaction was found between CMB presence and recanalization in predicting functional outcomes at 3 months. Conclusions- These results indicate that the presence of CMBs, and especially high burden and lobar location, are independent predictors of poor 3-month clinical outcomes and may increase symptomatic intracranial hemorrhage risk in acute ischemic stroke patients with recanalization. Our findings suggest that CMBs lead to more unfavorable effects in patients with recanalization after large vessel occlusion than in those without recanalization.

Pretreatment cerebral microbleeds and symptomatic intracerebral hemorrhage post-thrombolysis: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) are a possible predictor of symptomatic intracranial hemorrhage (sICH) and poor function outcome (PFO). We aimed to investigate the presence of CMBs on increased incidence of sICH and PFO in acute ischemic stroke patients receiving intravenous thrombolysis (IVT) treatment.

METHODS

We searched PubMed, EMBASE, and Cochrane Library from 1 January 1997 to 13 May 2018, for relevant studies and calculated the pooled relative risk (RR) for the incidence of sICH and PFO in patients with CMBs versus those without after IVT.

RESULTS

We included 2407 participants from nine studies. The cumulative sICH incidence was higher in patients with CMBs (6%, 95% CI 4-8%) than that in patients without CMBs (4%, 95% CI 2-6%) with pooled RR 1.51 (95% CI, 1.04-2.21; P = 0.031). Four studies including 1550 patients reported data on 3- to 6-month PFO. The cumulative PFO incidence was higher in patients with CMBs (53%, 95% CI 47-59%) than that in patients without CMBs (41%, 95% CI 36-46%) with pooled RR 1.25 (95% CI 1.11-1.41; P = 0.000).

CONCLUSIONS

The pretreatment CMBs were associated with increased incidence of sICH and PFO in acute ischemic stroke patients receiving IVT. However, it was not convincing enough to set the presence of CMBs as contraindication to IVT.

Cerebral White Matter Hyperintensities and Microbleeds in Acute Ischemic Stroke: Impact on Recanalization Therapies. A Review of the Literature

Cerebral white matter hyperintensities (WMH) and cerebral microbleeds (CMBs) are frequently seen on brain imaging acquired for acute ischemic stroke. Given the raising use of recanalization therapies - both intravenous and endovascular - the interest on the impact of WMH and CMBs on the risk of intracerebral hemorrhage and on functional outcome is growing. In this review, we will discuss the relevance of WMH and CMBs among patients with an acute ischemic stroke, focusing on the implications for recanalization therapies.

Susceptibility-weighted Imaging in Thrombolytic Therapy of Acute Ischemic Stroke

Objective:

To provide a comprehensive and latest overview of susceptibility-weighted imaging (SWI) in the application of thrombolysis in acute ischemic stroke, and to update the decision-making effect and clinical value of SWI on identifying stroke patients suitable for thrombolytic therapy and possible benefits and risks followed.

Data Sources:

Literatures referred to this review were collected from PubMed, Medline, and EMBASE published till May 2017, using the search terms including susceptibility-weighted imaging, gradient-echo, T2*, thrombolysis, recombinant tissue plasminogen activator (rt-PA), thrombolytic therapy, and stroke.

Study Selection:

Papers in English or with available English abstracts were considered, with no limitation of study design. References were also identified from the bibliographies of identified articles and the authors’ files.

Results:

SWI is of guiding significance for thrombolytic therapy in stroke patients, it can predict the location and length of thrombus and ischemic penumbra. It is worthy of noting that susceptibility vessel sign (SVS) on SWI can be used to predict recanalization after thrombolytic therapy and whether it is better to implement endovascular thrombolectomy in combination or alone. SWI is sensitive in detecting cerebral microbleed (CMB), and CMB might not be a contraindication for thrombolytic therapy, yet CMBs in multiple foci could possibly be related to intracranial hemorrhage (ICH) after thrombolysis. SVS and CMB on SWI sequence are of instructive value in performing antiplatelet therapy after thrombolytic therapy. Cerebral venous change on SWI is related to lower recanalization rate and poor outcome after thrombolysis.

Conclusions:

It seems that SWI can be applied to guide individualized thrombolytic therapies and assist clinicians in making better decisions by weighing benefits and risks. However, there still exist controversies about the relationship between signs on SWI and thrombolytic therapy.

Cerebral Microbleeds are an Independent Predictor of Hemorrhagic Transformation Following Intravenous Alteplase Administration in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Intravenous alteplase (rt-PA) increases the risk of hemorrhagic transformation of acute ischemic stroke. The objective of our study was to evaluate clinical, laboratory, and imaging predictors on forecasting the risk of hemorrhagic transformation following treatment with rt-PA. We also evaluated the factors associated with cerebral microbleeds that increase the risk of hemorrhagic transformation.

METHODS

Consecutive patients with acute ischemic stroke admitted between January 1, 2009 and December 31, 2013 were included in the study if they received IV rt-PA, had magnetic resonance imaging (MRI) of the brain on admission, and computed tomography or MRI of the brain at 24 (18-36) hours later to evaluate for the presence of hemorrhagic transformation. The clinical data, lipid levels, platelet count, MRI, and computed tomography images were retrospectively reviewed.

RESULTS

The study included 366 patients, with mean age 67 ± 15 years; 46% were women and 88% were white. The median National Institutes of Health Stroke Scale (NIHSS) score was 6 (interquartile range 3-15). Hemorrhagic transformation was observed in 87 (23.8%) patients and cerebral microbleeds were noted in 95 (25.9%). Patients with hemorrhagic transformation tended to be older, nonwhite, have atrial fibrillation, higher baseline NIHSS score, lower cholesterol and triglyceride levels, and cerebral microbleeds and nonlacunar infarcts. Patients with cerebral microbleeds were more likely to be older, have hypertension, hyperlipidemia, previous history of stroke, and prior use of antithrombotics. On multivariate analysis race, NIHSS score, nonlacunar infarct, and presence of cerebral microbleeds were independently associated with hemorrhagic transformation following treatment with rt-PA.

CONCLUSIONS

Presence of cerebral microbleeds is an independent predictor of hemorrhagic transformation of acute ischemic stroke following treatment with rt-PA.

Enlarged perivascular spaces are associated with health-related quality of life in patients with acute ischemic stroke

AIMS

This study explored the association between enlarged perivascular spaces (EPVS) and the health-related quality of life (HRQoL) in patients with acute ischemic stroke.

METHODS

This was an observational study of consecutively screened patients with acute ischemic stroke from March 2010 to March 2015. EPVS were rated in the basal ganglia and the centrum semiovale with a validated scale. The HRQoL was assessed 3 months after the stroke onset using the Stroke-Specific Quality of Life (SSQoL). Linear regression models were used to study the association between EPVS and HRQoL.

RESULTS

The study included 648 patients (mean age 65.8 years; 40.0% women) with mild to moderately severe stroke (median NIHSS score 2), of whom 640 (98.8%) exhibited signs of small vessel disease. The median EPVS scores in the basal ganglia and the centrum semiovale were 1 each. In linear regression analysis, EPVS in the basal ganglia were associated with a lower total SSQoL score (P = 0.02) and lower mobility (P = 0.01), mood (P = 0.03), and self-care (P < 0.01). EPVS in the centrum semiovale were associated only with a lower SSQoL work/productivity subscore (P = 0.002).

CONCLUSIONS

EPVS are associated with lower HRQoL in patients with mild to moderate acute ischemic stroke. Early identification and intervention of EPVS may improve HRQoL in stroke survivors.

Focal T2 and FLAIR hyperintensities within the infarcted area: A suitable marker for patient selection for treatment?

Background and purpose

Some authors use FLAIR imaging to select patients for stroke treatment. However, the effect of hyperintensity on FLAIR images on outcome and bleeding has been addressed in only few studies with conflicting results.

Methods

466 patients with anterior circulation strokes were included in this study. They all were examined with MRI before intravenous or endovascular treatment. Baseline data and 3 months outcome were recorded prospectively. Focal T2 and FLAIR hyperintensities within the ischemic lesion were evaluated by two raters, and the PROACT II classification was applied to assess bleeding complications on follow up imaging. Logistic regression analysis was used to determine predictors of bleeding complications and outcome and to analyze the influence of T2 or FLAIR hyperintensity on outcome.

Results

Focal hyperintensities were found in 142 of 307 (46.3%) patients with T2 weighted imaging and in 89 of 159 (56%) patients with FLAIR imaging. Hyperintensity in the basal ganglia, especially in the lentiform nucleus, on T2 weighted imaging was the only independent predictor of any bleeding after reperfusion treatment (33.8% in patients with vs. 18.2% in those without; p = 0.003) and there was a non-significant trend for more bleedings in patients with FLAIR hyperintensity within the basal ganglia (p = 0.069). However, there was no association of hyperintensity on T2 weighted or FLAIR images and symptomatic bleeding or worse outcome.

Conclusion

Our results question the assumption that T2 or FLAIR hyperintensities within the ischemic lesion should be used to exclude patients from reperfusion therapy, especially not from endovascular treatment.

Microbleeds, Cerebral Hemorrhage, and Functional Outcome After Stroke Thrombolysis

Background and Purpose—

We assessed whether the presence, number, and distribution of cerebral microbleeds (CMBs) on pre-intravenous thrombolysis MRI scans of acute ischemic stroke patients are associated with an increased risk of intracerebral hemorrhage (ICH) or poor functional outcome.

Methods—

We performed an individual patient data meta-analysis, including prospective and retrospective studies of acute ischemic stroke treated with intravenous tissue-type plasminogen activator. Using multilevel mixed-effects logistic regression, we investigated associations of pre-treatment CMB presence, burden (1, 2–4, ≥5, and >10), and presumed pathogenesis (cerebral amyloid angiopathy defined as strictly lobar CMBs and noncerebral amyloid angiopathy) with symptomatic ICH, parenchymal hematoma (within [parenchymal hemorrhage, PH] and remote from the ischemic area [remote parenchymal hemorrhage, PHr]), and poor 3- to 6-month functional outcome (modified Rankin score >2).

Results—

In 1973 patients from 8 centers, the crude prevalence of CMBs was 526 of 1973 (26.7%). A total of 77 of 1973 (3.9%) patients experienced symptomatic ICH, 210 of 1806 (11.6%) experienced PH, and 56 of 1720 (3.3%) experienced PHr. In adjusted analyses, patients with CMBs (compared with those without CMBs) had increased risk of PH (odds ratio: 1.50; 95% confidence interval: 1.09–2.07; P =0.013) and PHr (odds ratio: 3.04; 95% confidence interval: 1.73–5.35; P <0.001) but not symptomatic ICH. Both cerebral amyloid angiopathy and noncerebral amyloid angiopathy patterns of CMBs were associated with PH and PHr. Increasing CMB burden category was associated with the risk of symptomatic ICH ( P =0.014), PH ( P =0.013), and PHr ( P <0.00001). Five or more and >10 CMBs independently predicted poor 3- to 6-month outcome (odds ratio: 1.85; 95% confidence interval: 1.10–3.12; P =0.020; and odds ratio: 3.99; 95% confidence interval: 1.55–10.22; P =0.004, respectively).

Conclusions—

Increasing CMB burden is associated with increased risk of ICH (including PHr) and poor 3- to 6-month functional outcome after intravenous thrombolysis for acute ischemic stroke.

The Presence of Previous Cerebral Microbleeds Has a Negative Effect on Hypertensive Intracerebral Hemorrhage Recovery

Background and Purpose: Cerebral microbleeds are an intracerebral microangiopathy with bleeding tendency found in intracerebral hemorrhage patients. However, studies about cerebral microbleed effects on the prognosis of hypertensive intracerebral hemorrhage patients are rare. We performed a prospective study to discuss not only the risk factors of cerebral microbleed incidence in hypertensive intracerebral hemorrhage patients but also the relevance of cerebral microbleeds with silent brain infarction, hemorrhage and prognosis.

Methods: This study enrolled 100 patients diagnosed with hypertensive intracerebral hemorrhage within 3 days after onset. Magnetic resonance imaging including susceptibility-weighted imaging and diffusion-weighted imaging (DWI) were utilized to examine patients on the fifth day after onset. Regular follow-ups were performed to examine the following clinical cerebrovascular events and vascular deaths in 1 year.

Results: Cerebral microbleeds were observed in 55 (55%) patients. Multiple logistic regression analysis showed that over-aging, elevation of serum creatinine, and leukoaraiosis were independently associated with cerebral microbleeds. In addition, higher silent brain infarction prevalence was observed in patients with cerebral microbleeds. In contrast, none of the cerebral microbleed patients exhibited cerebral microbleeds ≥5, which is an independent risk factor of poor 3-month neurological function recovery. During the 1-year follow-up, 14 subjects presented clinical cerebrovascular events or vascular death. The Cox proportional hazards model implicated that atrial fibrillation, cerebral microbleeds ≥5 and silent brain infarction were independent predictive factors for these events.

Conclusions: Over-aging combined with an elevation of serum creatinine and leukoaraiosis were independent risk factors of cerebral microbleeds. Patients with cerebral microbleeds were more likely to exhibit silent brain infarction. Poor recovery of 3-month neurological function was observed in hypertensive intracerebral hemorrhage patients with cerebral microbleeds ≥5. Cerebral microbleeds ≥5 or silent brain infarction might also indicate an elevated risk of future cerebrovascular events and vascular death.

Evaluation of the role of susceptibility-weighted imaging in thrombolytic therapy for acute ischemic stroke

We inspected low-intensity venous signals and microbleeds in patients with acute ischemic stroke (AIS) using susceptibility-weighted imaging (SWI) before and after administration of within-thrombolytic-time-window thrombolytic therapies, and observed their prognosis and safety, in order to guide individualized thrombolytic therapies. Patients with AIS were divided into groups A or B according to the presence of symmetric or asymmetric veins on SWI, and were re-inspected by SWI after intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA). The National Institutes of Health stroke scale (NIHSS) score before treatment and at 1-h and 24-h posttreatment in the two groups were 11.9, 7.3, and 7.1 in group A, 12.4, 8.2, and 7.9 in group B, significant difference was detected between the two groups after treatment. The 90-day mortality rate was 0, and the incidences of cerebral microbleeds (CMBs) and symptomatic cerebral hemorrhage (SCH) were 17.6%, and 0% in group A, 25.6% and 0% in group B, respectively. The incidences of CMBs and SCH in group A were lower than those in group B, but the intergroup differences were not statistically significant (P>0.05). The 90-day neurological improvement rates in the two groups were 70.2% and 58.1%, respectively, and group A showed a significantly better prognosis than group B (P<0.05). Thus, low-intensity venous signals in SWI can be used to evaluate a low level of perfusion, post-thrombolytic prognosis, and bleeding indexes, and can therefore be used to guide individualized thrombolytic therapies.

Prevention of Stroke in Patients With Silent Cerebrovascular Disease: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

Two decades of epidemiological research shows that silent cerebrovascular disease is common and is associated with future risk for stroke and dementia. It is the most common incidental finding on brain scans. To summarize evidence on the diagnosis and management of silent cerebrovascular disease to prevent stroke, the Stroke Council of the American Heart Association convened a writing committee to evaluate existing evidence, to discuss clinical considerations, and to offer suggestions for future research on stroke prevention in patients with 3 cardinal manifestations of silent cerebrovascular disease: silent brain infarcts, magnetic resonance imaging white matter hyperintensities of presumed vascular origin, and cerebral microbleeds. The writing committee found strong evidence that silent cerebrovascular disease is a common problem of aging and that silent brain infarcts and white matter hyperintensities are associated with future symptomatic stroke risk independently of other vascular risk factors. In patients with cerebral microbleeds, there was evidence of a modestly increased risk of symptomatic intracranial hemorrhage in patients treated with thrombolysis for acute ischemic stroke but little prospective evidence on the risk of symptomatic hemorrhage in patients on anticoagulation. There were no randomized controlled trials targeted specifically to participants with silent cerebrovascular disease to prevent stroke. Primary stroke prevention is indicated in patients with silent brain infarcts, white matter hyperintensities, or microbleeds. Adoption of standard terms and definitions for silent cerebrovascular disease, as provided by prior American Heart Association/American Stroke Association statements and by a consensus group, may facilitate diagnosis and communication of findings from radiologists to clinicians.

High-sensitivity cardiac troponin T levels and risk of cerebral microbleeds in acute ischemic stroke patients with atrial fibrillation and/or rheumatic heart disease

BACKGROUND AND OBJECTIVE

Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels are associated with coronary disease and small-vessel ischemic stroke through their associations with atherosclerosis. Considering the relationship between atherosclerosis and cerebral microbleeds (CMBs), the purpose of this study was to examine associations between serum hs-cTnT levels and risk of CMBs in acute ischemic stroke patients.

METHODS

This prospective study involved consecutively recruited acute ischemic stroke patients with atrial fibrillation and/or rheumatic heart disease treated at a large tertiary care hospital in southwestern China. Clinico-demographic data were collected and analyzed by logistic regression to identify the relationship between serum hs-cTnT levels and CMB occurrence and location.

RESULTS

In the final analysis, of 66 patients (27 males; mean age, 68.7years), 39 (59.1%) had CMBs. Hs-cTnT levels were not associated with risk of strictly lobar CMBs. However, after adjusting age, sex, current alcohol consumption, total cholesterol, hypertension, diabetes mellitus, prior antithrombotic therapy and NIHSS on admission, patients in the higher tertile were more likely to have CMBs and deep or infratentorial CMBs (P<0.05) compared with the lower hs-cTnT tertile.

CONCLUSION

Hs-cTnT may be an independent predictor for the occurrence of CMBs, particularly of deep or infratentorial CMBs. This finding justifies further research into how hs-cTnT levels may contribute to CMBs and potentially other subclinical small-vessel diseases.

Remote Intracerebral Hemorrhage After Intravenous Thrombolysis

Background and Purpose—

Remote parenchymal hemorrhage (rPH) after intravenous thrombolysis with recombinant tissue-type plasminogen activator may be associated with cerebral amyloid angiopathy, although supportive data are limited. We aimed to investigate risk factors of rPH after intravenous thrombolysis with recombinant tissue-type plasminogen activator.

Methods—

This is an observational study of patients with ischemic stroke who were treated with intravenous thrombolysis with recombinant tissue-type plasminogen activator and were included in a multicenter prospective registry. rPH was defined as any extraischemic hemorrhage detected in the follow-up computed tomography. We collected demographic, clinical, laboratory, radiological, and outcome variables. In the subset of patients who underwent a magnetic resonance imaging examination, we evaluated the distribution and burden of cerebral microbleeds, cortical superficial siderosis, leukoaraiosis, and recent silent ischemia in regions anatomically unrelated to the ischemic lesion that caused the initial symptoms. We compared patients with rPH with those without rPH or parenchymal hemorrhage. Independent risk factors for rPH were obtained by multivariable logistic regression analyses.

Results—

We evaluated 992 patients (mean age, 74.0±12.6 years; 52.9% were men), and 408 (41%) of them underwent a magnetic resonance imaging. Twenty-six patients (2.6%) had a rPH, 8 (0.8%) had both rPH and PH, 58 (5.8%) had PH, and 900 (90.7%) had no bleeding complication. Lobar cerebral microbleeds (odds ratio, 8.0; 95% confidence interval, 2.3–27.2) and recent silent ischemia (odds ratio, 4.8; 95% confidence interval, 1.6–14.1) increased the risk of rPH.

Conclusions—

The occurrence of rPH after intravenous thrombolysis with recombinant tissue-type plasminogen activator in patients with ischemic stroke is associated with lobar cerebral microbleeds and multiple ischemic lesions in different regions.

Impact of leukoaraiosis on parenchymal hemorrhage in elderly patients treated with thrombolysis

INTRODUCTION

Severity of vascular damage of white matter may predict hemorrhagic transformation (HT). We assess the relationship between leukoaraiosis (LA) severity and the type of hemorrhagic transformation in elderly patients treated with thrombolysis.

METHODS

We retrospectively analyzed the clinical data and pretreatment magnetic resonance imaging (MRI) of 180 consecutive ischemic stroke patients aged over 75 years. LA severity was graded according to the Fazekas scale, and acute diffusion-weighted-imaging (DWI) lesion volumes were semi-automatically outlined. Predictors of hemorrhagic infarction (HI) and parenchymal hemorrhage (PH) were identified using logistic regression analysis and exact multinomial logistic analysis.

RESULTS

HT occurred in 31 patients (17 %). Baseline National Institute of Health Stroke Score (NIHSS; p = 0.008), severe LA (p = 0.02), and diffusion lesion volume (p = 0.02) were predictors of HT in univariable logistic regression. Adjusted to lesion volume and baseline NIHSS score, exact multinomial logistic analysis showed that severe LA was the only independent predictor of parenchymal hemorrhage (p = 0.03).

CONCLUSION

In elderly patients, LA severity better predicts parenchymal hemorrhage than infarct size.

A cohort study of relationship between serum calcium levels and cerebral microbleeds (CMBs) in ischemic stroke patients with AF and/or RHD

Calcium is an essential element for life and has cerebroprotective property in stroke patients. Low serum calcium levels were found to be related to large hematoma volumes in intracerebral hemorrhagic patients and hemorrhagic transformation in ischemic stroke patients after thrombolysis. However, their impact on hemorrhage-prone small vessel disease represented by cerebral microbleeds (CMBs) is uncertain. We aim to investigate whether low serum calcium levels are associated with presence and location of CMBs.Ischemic stroke patients with atrial fibrillation (AF) and/or rheumatic heart disease admitted to our hospital were consecutively and prospectively enrolled. Demographic and clinical information were collected and analyzed according to the occurrence and location of CMBs, and levels of serum calcium. We used logistic regression analysis to estimate the multivariable adjusted relationship between serum calcium levels and the presence or location of CMBs.Among the 67 patients (28 males; mean age, 67.3 years) in the final analysis, 39 (58.2%) were found to have CMBs. After adjustment for age, sex, smoking habits, drinking habits, and renal impairment, the presence of CMBs and deep CMBs was, respectively, 4.96- and 4.83-fold higher in patients with lower serum calcium levels (≤2.15 mmol/L) than in patients with higher serum calcium levels.Lower serum calcium levels (≤2.15 mmol/L) are independently associated with the presence of CMBs and deep CMBs in ischemic stroke patients with AF and/or rheumatic heart disease, which should be verified and extended in large cohorts, with other types of stroke patients and the general population.

Cerebral microbleeds and postthrombolysis intracerebral hemorrhage risk Updated meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to assess whether the presence of cerebral microbleeds (CMBs) on pretreatment MRI scans of patients with acute ischemic stroke treated with thrombolysis is associated with an increased risk of symptomatic intracerebral hemorrhage (ICH).

METHODS

We searched PubMed for relevant studies and calculated pooled odds ratios (ORs) for symptomatic ICH, using the Mantel–Haenszel fixed-effects method, among individuals with vs without CMBs on pretreatment MRI scans. To minimize potential bias, sensitivity analysis was performed including studies providing data on patients treated only with IV thrombolysis.

RESULTS

Ten eligible studies including 2,028 patients were pooled in meta-analysis. The overall prevalence of CMBs was 23.3%. Among patients with CMBs, 40 of 472 (8.5%; 95%confidence interval [CI]: 6.1%–11.4%) experienced a symptomatic ICH after thrombolysis compared with 61 of 1,556 patients (3.9%; 95% CI: 3%–5%) without CMBs. The pooled OR of ICH across all studies was 2.26 (95%CI: 1.46–3.49; p , 0.0001). Eight studies, including 1,704 patients (n 5 401 with CMBs), provided data on patients treated with IV thrombolysis only; OR for the presence of CMBs and the development of symptomatic ICH was 2.87 (95%CI: 1.76–4.69; p , 0.0001).

CONCLUSIONS

Our meta-analysis of the available published data demonstrates an increased risk of symptomatic ICH after thrombolysis for acute ischemic stroke in patients with CMBs. However, we cannot fully exclude bias or confounding, so our results should be considered hypothesis generating. Detecting CMBs should not prevent thrombolytic treatment based on present evidence. Further analyses, taking into account CMB number and location, as well as measures of functional outcome, are needed.

Clinical Outcome in Acute Ischemic Stroke Patients With Microbleeds After Thrombolytic Therapy: A Meta-Analysis

It remains unclear whether preexisting cerebral microbleeds (CMBs) increase the risks of worse functional outcome after thrombolytic therapy. We performed a systematic review and meta-analysis to assess the risk of unfavorable outcome in patients with acute ischemic stroke and CMBs.We searched EMBASE, PubMed, and Web of Science for relevant studies assessing functional outcome in the patients with CMBs following thrombolytic therapy. Fixed-effects and random-effects models were performed.Five eligible studies including 1974 patients were pooled in meta-analysis. The prevalence of CMBs was 24.3%. The pooled analysis demonstrates odds ratio for preexisting CMBs and the achievement of favorable outcome to be 0.69 (95% CI 0.56-0.86; P = 0.001) with no evidence of statistical heterogeneity (I = 46.7%, P = 0.112).Our meta-analysis of available published data demonstrates an increased risk of worse functional outcome after thrombolytic therapy for acute ischemic stroke in patients with pre-existing CMBs. Future studies are needed to determine whether the risk outweigh the expected benefit of reperfusion therapies.

Extensive cerebral microbleeds predict parenchymal haemorrhage and poor outcome after intravenous thrombolysis

PURPOSE

Thrombolysis-related haemorrhagic transformation (HT) subtypes may have different prognostic implications. We aimed to analyse the impact of cerebral microbleeds (CMBs) burden on HT subtypes and outcome after intravenous thrombolysis.

METHODS

We retrospectively examined clinical and radiological data from 333 consecutive patients with acute ischaemic stroke who underwent susceptibility-weighted imaging before intravenous thrombolysis. Logistic regression analysis was used to determine the impact of CMBs on HT subtypes and neurological outcome.

RESULTS

We observed 596 CMBs in 119 (39.7%) patients on initial gradient-recalled echo scans. HT occurred in 88 (29.3%) patients, among which 62 were haemorrhagic infarction and 26 were parenchymal haemorrhage (PH). Logistic regression analysis indicated that the presence of extensive (≥ 3) CMBs was independently associated with PH (OR 6.704; 95% CI 2.054 to 21.883; p = 0.002) and poor clinical outcome (OR 2.281; 95% CI 1.022 to 5.093; p = 0.044).

CONCLUSIONS

The presence of extensive (≥ 3) CMBs increased the risk of PH 24 h after intravenous thrombolysis, and predicted poor clinical outcome independently.

Microbleed Status and 3-Month Outcome After Intravenous Thrombolysis in 717 Patients With Acute Ischemic Stroke

Background and Purpose—

Whether cerebral microbleeds (CMBs) detected on pretreatment magnetic resonance imaging increase the risks of symptomatic intracranial hemorrhage (sICH) and, most importantly, poor outcome in patients treated by intravenous thrombolysis for acute ischemic stroke is still debated. We assessed the effect of CMB presence and burden on 3-month modified Rankin Scale and sICH in a multicentric cohort.

Methods—

We analyzed prospectively collected data of consecutive patients solely treated by intravenous thrombolysis for acute ischemic stroke, in 2 centers where magnetic resonance imaging is the first-line pretreatment imaging. Neuroradiologists blinded to clinical data rated CMBs on T2* sequence using a validated scale. Logistic regressions were used to assess relationships between CMBs and 3-month modified Rankin Scale or sICH.

Results—

Among 717 patients, 150 (20.9%) had ≥1 CMBs. CMB burden was associated with worse modified Rankin Scale in univariable shift analysis (odds ratio, 1.07; 95% confidence interval, 1.00–1.15 per 1-CMB increase; P =0.049), but significance was lost after adjustment for age, hypertension, and atrial fibrillation (odds ratio, 1.03; 95% confidence interval, 0.96–1.11 per 1-CMB increase; P =0.37). Results remained nonsignificant when taking into account CMB location or presumed underlying vasculopathy. The incidence of sICH ranged from 3.8% to 9.1%, depending on the definition. Neither CMB presence, burden, location, nor presumed underlying vasculopathy was independently associated with sICH.

Conclusions—

Poor outcome or sICH was not associated with CMB presence or burden on pre–intravenous thrombolysis magnetic resonance imaging after adjustment for confounding factors. An individual patient data meta-analysis is needed to determine whether a subgroup of patients with CMBs carries an independent risk of poor outcome that might outweigh the expected benefit of intravenous thrombolysis.

Protected stent retriever thrombectomy prevents iatrogenic emboli in new vascular territories

Introduction

Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques.

Methods

Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both.

Results

In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n = 3) or 3 (n = 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one.

Conclusion

Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.

Younger Stroke Patients With Large Pretreatment Diffusion-Weighted Imaging Lesions May Benefit From Endovascular Treatment

BACKGROUND AND PURPOSE

Lesion volume on diffusion-weighted magnetic resonance imaging (DWI) before acute stroke therapy is a predictor of outcome. Therefore, patients with large volumes are often excluded from therapy. The aim of this study was to analyze the impact of endovascular treatment in patients with large DWI lesion volumes (>70 mL).

METHODS

Three hundred seventy-two patients with middle cerebral or internal carotid artery occlusions examined with magnetic resonance imaging before treatment since 2004 were included. Baseline data and 3 months outcome were recorded prospectively. DWI lesion volumes were measured semiautomatically.

RESULTS

One hundred five patients had lesions >70 mL. Overall, the volume of DWI lesions was an independent predictor of unfavorable outcome, survival, and symptomatic intracerebral hemorrhage (P<0.001 each). In patients with DWI lesions >70 mL, 11 of 31 (35.5%) reached favorable outcome (modified Rankin scale score, 0-2) after thrombolysis in cerebral infarction 2b-3 reperfusion in contrast to 3 of 35 (8.6%) after thrombolysis in cerebral infarction 0-2a reperfusion (P=0.014). Reperfusion success, patient age, and DWI lesion volume were independent predictors of outcome in patients with DWI lesions >70 mL. Thirteen of 66 (19.7%) patients with lesions >70 mL had symptomatic intracerebral hemorrhage with a trend for reduced risk with avoidance of thrombolytic agents.

CONCLUSIONS

There was a growing risk for poor outcome and symptomatic intracerebral hemorrhage with increasing pretreatment DWI lesion volumes. Nevertheless, favorable outcome was achieved in every third patient with DWI lesions >70 mL after successful endovascular reperfusion, whereas after poor or failed reperfusion, outcome was favorable in only every 12th patient. Therefore, endovascular treatment might be considered in patients with large DWI lesions, especially in younger patients.

Prognostic Impact of Cerebral Small Vessel Disease on Stroke Outcome

Cerebral small vessel disease (SVD), which includes white matter hyperintensities (WMHs), silent brain infarction (SBI), and cerebral microbleeds (CMBs), develops in a conjunction of cumulated injuries to cerebral microvascular beds, increased permeability of blood-brain barriers, and chronic oligemia. SVD is easily detected by routine neuroimaging modalities such as brain computed tomography or magnetic resonance imaging. Research has revealed that the presence of SVD markers may increase the risk of future vascular events as well as deteriorate functional recovery and neurocognitive trajectories after stroke, and such an association could also be applied to hemorrhagic stroke survivors. Currently, the specific mechanistic processes leading to the development and manifestation of SVD risk factors are unknown, and further studies with novel methodological tools are warranted. In this review, recent studies regarding the prognostic impact of WMHs, SBI, and CMBs on stroke survivors and briefly summarize the pathophysiological concepts underlying the manifestation of cerebral SVD.

Mechanical thrombectomy for acute ischemic stroke with cerebral microbleeds

Background

The influence of cerebral microbleeds (CMBs) on post-thrombolytic hemorrhagic transformation (HT) in patients with acute ischemic stroke remains controversial.

Objective

To investigate the association of CMBs with HT and clinical outcomes among patients with large-vessel occlusion strokes treated with mechanical thrombectomy.

Methods

We analyzed patients with acute stroke treated with Merci Retriever, Penumbra system or stent-retriever devices. CMBs were identified on pretreatment T2-weighted, gradient-recall echo MRI. We analyzed the association of the presence, burden, and distribution of CMBs with HT, procedural complications, in-hospital mortality, and clinical outcome.

Results

CMBs were detected in 37 (18.0%) of 206 patients. Seventy-three foci of microbleeds were identified. Fourteen patients (6.8%) had ≥2 CMBs, only 1 patient had ≥5 CMBs. Strictly lobar CMBs were found in 12 patients, strictly deep CMBs in 12 patients, strictly infratentorial CMBs in 2 patients, and mixed CMBs in 11 patients. There were no significant differences between patients with CMBs and those without CMBs in the rates of overall HT (37.8% vs 45.6%), parenchymal hematoma (16.2% vs 19.5%), procedure-related vessel perforation (5.4% vs 7.1%), in-hospital mortality (16.2% vs 18.3%), and modified Rankin Scale score 0–3 at discharge. CMBs were not independently associated with HT or in-hospital mortality in patients treated with either thrombectomy or intravenous thrombolysis followed by thrombectomy.

Conclusions

Patients with CMBs are not at increased risk for HT and mortality following mechanical thrombectomy for acute stroke. Excluding such patients from mechanical thrombectomy is unwarranted. The risk of HT in patients with ≥5 CMBs requires further study.

Imaging of cerebrovascular disorders: precision medicine and the collaterome

Imaging of stroke and neurovascular disorders has profoundly enhanced clinical practice and related research during the last 40 years since the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) enabled mapping of the brain. We highlight recent advances in neurovascular imaging. We describe how the convergence of readily available data and new clinical trial paradigms will recast our methods for studying the neurovascular patient. The application of a precision medicine approach to the collaterome, a comprehensive synthesis of neurovascular pathophysiology, will entail novel methods for clinical trial randomization, collection of routine and clinical trial imaging results, data archiving, and analysis.

Number of Cerebral Microbleeds and Risk of Intracerebral Hemorrhage After Intravenous Thrombolysis

Background and Purpose—

Cerebral microbleeds (CMBs) are found in a substantial proportion of patients with ischemic stroke eligible for treatment with intravenous thrombolysis. Until now, there is limited data on the impact of multiple CMBs on occurrence of intracerebral hemorrhage (ICH) after intravenous thrombolysis.

Methods—

Between 2008 and 2013, all patients receiving MRI-based intravenous thrombolysis were identified within our prospective thrombolysis register. Number of CMBs was rated on pretreatment T2*-weighted MRI by a rater blinded to clinical data and follow-up. Outcomes of interest were occurrence of symptomatic ICH (sICH) and parenchymal hemorrhage (PH).

Results—

Among 326 included patients, 52 patients had a single CMB (16.0%), 19 had 2 to 4 CMBs (5.8%), and 10 had ≥5 CMBs (3.1%). Frequency of sICH/PH was 1.2%/5.7% in patients without CMBs, 3.8%/3.8% in patients with a single CMB, 10.5%/21.1% in patients with 2 to 4 CMBs, and 30.0%/30.0% in patients with ≥5 CMBs, respectively (each P for trend <0.01). The unadjusted odds ratio per additional CMB for sICH was 1.19 (95% confidence interval, 1.07–1.33; P <0.01) and for PH was 1.13 (95% confidence interval, 1.03–1.24; P =0.01). Compared with patients without CMBs, both patients with 2 to 4 CMBs ( P =0.02/ P =0.02) and patients with ≥5 CMBs ( P <0.01/ P <0.01) had significantly increased odds ratios for sICH and PH, whereas in patients with a single CMB, odds ratios were not significantly increased ( P =0.21/ P =0.59). The association of CMB burden with sICH/PH remained significant after adjustment for possible confounders (age, age-related white matter changes score, atrial fibrillation, onset-to-treatment time, prior statin use, and systolic blood pressure on admission).

Conclusions—

Our findings indicate a higher risk of sICH and PH after intravenous thrombolysis when multiple CMBs are present, with a graded relationship to increasing baseline CMB number.