Quantity of Cerebral Microbleeds, Antiplatelet Therapy, and Intracerebral Hemorrhage Outcomes: A Systematic Review and Meta-analysis

Relationship between human oral microbiome dysbiosis and neuropsychiatric diseases: An updated overview

The role of the gut-brain axis in mental health disorders has been extensively studied. As the oral cavity is the starting point of the digestive tract, the role that the oral microbiota plays in mental health disorders has gained recent attention. Oral microbiota can enter the bloodstream and trigger inflammatory responses or translocate to the brain through the trigeminal nerve or olfactory system. Hence, the concept of the oral microbiota-brain axis has emerged. Several hypotheses have been suggested that the oral microbiota can enter the gastrointestinal tract and affect the gut-brain axis; however, literature describing oral-brain communication remains limited. This review summarizes the characteristics of oral microbiota and its mechanisms associated with mental health disorders. Through a comprehensive examination of the relationship between oral microbiota and various neuropsychiatric diseases, such as anxiety, depression, schizophrenia, autism spectrum disorder, epilepsy, Parkinson's disease, and dementia, this review seeks to identify promising avenues of future research.

Cerebral microbleeds. Utility of SWI sequences

OBJECTIVES

Define the concept of cerebral microbleeds (CMBs) and describe the most useful MRI sequences for detecting this finding. Review the entities that most frequently present with CMBs and that may benefit from the use of susceptibility-weighted imaging (SWI) sequences.

CONCLUSIONS

SWI is a useful MRI sequence for the detection and characterization of microhemorrhages, venous structures and other sources of susceptibility in imaging. SWI is particularly sensitive to local magnetic field inhomogeneities generated by certain substances and is superior to T2* GRE sequences for this assessment. CMBs may be seen in different neurologic conditions, in certain infrequent clinical contexts and have a key role as a biomarker status in gliomas (ITTS) and as a marker of inflammatory activity in multiple sclerosis.

Characteristics of Focused Ultrasound Mediated Blood-Brain Barrier Opening in Magnetic Resonance Images

OBJECTIVE

The blood-brain barrier (BBB) is an obstacle for molecules to pass through from blood to the brain. Focused ultrasound is a new method which temporarily opens the BBB, which makes pharmaceutical delivery or removal of neurodegenerative proteins possible. This study was demonstrated to review our BBB opening procedure with magnetic resonance guided images and find specific patterns in the BBB opening.

METHODS

In this study, we reviewed the procedures and results of two clinical studies on BBB opening using focused ultrasound regarding its safety and clinical efficacy. Magnetic resonance images were also reviewed to discover any specific findings.

RESULTS

Two clinical trials showed clinical benefits. All clinical trials demonstrated safe BBB opening, with no specific side effects. Magnetic resonance imaging showed temporary T1 contrast enhancement in the sonication area, verifying the BBB opening. Several low-signal intensity spots were observed in the T2 susceptibility-weighted angiography images, which were also reversible and temporary. Although these spots can be considered as microbleeding, evidence suggests these are not ordinary microbleeding but an indicator for adequate BBB opening.

CONCLUSION

Magnetic resonance images proved safe and efficient BBB opening in humans, using focused ultrasound.

Role of LDL-C level alteration in increased mortality risks in spontaneous intracerebral hemorrhage patients: Systematic review and meta-analysis

Background

Current studies indicate a contradictory relationship between decreased mortality risks of spontaneous intracerebral hemorrhage (sICH) and elevated low-density lipoprotein cholesterol (LDL-C) levels. Thus, this meta-analysis was designed to examine the involvement of high LDL-C levels in a lower mortality risk of sICH patients.

Methods

PubMed, Cochrane, and Embase databases were searched up to the date of August 3rd, 2022. Pooled odds ratio (OR) with a 95% confidence interval (CI) was estimated for the higher vs. lower serum LDL-C level groups. Subgroup and sensitivity analyses were also carried out. Egger's test was applied to detect any potential publication bias.

Results

Of 629 citations reviewed, 8 eligible cohort studies involving 83,013 patients were enrolled in this meta-analysis. Compared with lower serum LDL-C levels containing patients, higher serum LDL-C patients exhibited significantly decreased risks of 3-month mortality (OR: 0.51; 95%CI: 0.33-0.78; I² = 47.8%); however, the LDL-C level change wasn't significantly associated with in-hospital mortality risks (OR: 0.92; 95%CI: 0.63-1.33; I² = 91.4%) among sICH subjects. All studies included were classified as high-quality investigations.

Conclusions

This meta-analysis suggests a higher LDL-C level may decrease the mortality risk in sICH patients. LDL-C level increase is inversely associated with the 3-month mortality risks in these patients but not significantly correlated with the in-hospital mortality risks. Further well-designed prospective studies with extended follow-up periods are needed to confirm these findings and explore underlying cross-talks.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022318318, identifier: PROSPERO 2022 CRD42022318318.

Urinary Immunoglobulin G Is Associated with Deep and Infratentorial Cerebral Microbleeds in Stroke Patients

BACKGROUND

Cerebral microbleeds (CMBs) detected on susceptibility-weighted imaging (SWI) are associated with cerebral small vessel disease. Chronic kidney disease and microalbuminuria have been associated with the presence of CMBs in stroke patients. Urinary immunoglobulin G (IgG) is measured to document glomerular injury; however, the relationship between urinary IgG and CMBs is unknown.

METHODS

We retrospectively enrolled consecutive patients who had been admitted with transient ischemic attack (TIA) or ischemic stroke and identified those who had undergone SWI and a spot urine test. The location of CMBs was classified on magnetic resonance imaging as strictly lobar, deep/infratentorial (D/I), or mixed areas. We analyzed the association between urinary IgG and the presence and location of CMBs.

RESULTS

We included 298 patients (86 female, median age 70 years, median eGFR 65.8 mL/min/1.73 m2). Positive urinary IgG and CMB results were found in 58 (19%) and 160 patients (54%), respectively. Urinary IgG positivity was significantly associated with CMBs compared with non-CMBs (28% vs. 9%, p < 0.001), and with D/I or mixed CMBs compared with non-D/I or mixed CMBs (34% vs. 10%, p < 0.001). Multivariate analysis revealed that urinary IgG and hypertension positivity were strongly associated with D/I or mixed CMBs (OR 3.479, 95% CI: 1.776-6.818, p < 0.001; OR 3.415, 95% CI: 1.863-6.258, p < 0.001).

CONCLUSIONS

Urinary IgG was associated with the prevalence of D/I or mixed location CMBs in TIA or ischemic stroke patients. Our findings provide new insights into the association between urinary IgG and the distribution of CMBs.

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.

Epidemiology of cerebral microbleeds and risk of adverse outcomes in atrial fibrillation: a systematic review and meta-analysis

AIMS

The aim of this study is to perform a systematic review and meta-analysis on the epidemiology of cerebral microbleeds (CMBs) and the risk of intracranial haemorrhage (ICH) and ischaemic stroke (IS) in patients with atrial fibrillation (AF).

METHODS AND RESULTS

PubMed and EMBASE databases were systematically searched from inception to 6 March 2021. All studies reporting the prevalence of CMBs and incidence of ICH and IS in AF patients with and without CMBs were included. Meta-analysis was conducted using random-effect models; odds ratios (ORs), 95% confidence intervals (CIs), and prediction intervals (PIs) were calculated for each outcome. Subgroup analyses were performed according to the number and localization of CMBs. A total of 562 studies were retrieved, with 17 studies finally included in the meta-analysis. Prevalence of CMBs in AF population was estimated at 28.3% (95% CI: 23.8-33.4%). Individuals with CMBs showed a higher risk of ICH (OR: 3.04, 95% CI: 1.83-5.06, 95% PI 1.23-7.49) and IS (OR: 1.78, 95% CI: 1.26-2.49, 95% PI 1.10-2.87). Patients with ≥5 CMBs showed a higher risk of ICH. Metaregression showed how higher of prevalence of diabetes mellitus in AF cohort is associated with higher prevalence of CMBs.

CONCLUSIONS

Cerebral microbleeds are common in patients with AF, found in almost one out of four subjects. Cerebral microbleeds were associated with both haemorrhagic and thromboembolic events in AF patients. Moreover, the risk of ICH increased consistently with the burden of CMBs. Cerebral microbleeds may represent an important overlooked risk factor for both ICH and IS in adults with AF.

Cerebral Microbleed Burden in Ischemic Stroke Patients on Aspirin: Prospective Cohort of Intracranial Hemorrhage

Objective: This investigation aimed at studying the prevalence of cerebral microbleeds (CMBs), including risk factors and the correlation of CMBs to ischemic stroke (IS) patient end results.

Methods: Four hundred and fifty-nine acute IS cases were recruited between April 2014 and December 2016. Cerebral microbleeds were analyzed using susceptibility-weighted imaging (SWI) brain MRI scan. The enrolled patients with acute IS were followed up for 12–24 months, with a median follow-up time of 19 months. The follow-up endpoint events including recurrent ischemic stroke (RIS), intracranial hemorrhage (ICH), transient ischemic attack (TIA), mortality, and cardiovascular events. The associations between vascular risk factors and CMBs in IS patients were analyzed using univariate and multivariate logistic regression analysis. Cox regression model was employed for evaluating CMB impact on clinical outcome.

Results: Among 459 enrolled patients, 187 (40.7%) had CMBs and 272 (59.2%) had no CMB. In comparison with patients with no CMBs, age was higher and hypertension was more frequent in patients with CMBs. Multivariate logistic regression analyses revealed age and hypertension were independently associated with the presence of CMBs. Among the patient cohort, 450 cases completed the follow-up. During the follow-up period, 22 (4.9%) of patients developed ICH, 12 (2.7%) developed TIA, 68 (15.1%) developed RIS, cardiovascular events occurred in 20 (4.44%), and 13 (2.89%) cases were mortalities. Compared with patients without CMBs, IS patients with CMBs have an increased prevalence of ICH (p < 0.05). However, no statistically valid variations regarding other outcome incidences between both groups was identified (p > 0.05). The incidence of ICH was elevated in tandem with elevations in number of CMBs. Following adjusting for age, multivariate Cox proportional-hazards regression analysis revealed that CMBs ≥10 were independent predictors of ICH in acute IS patients.

Conclusion: Age and hypertension are independently associated with the presence of CMBs. Intracranial hemorrhage incidence rate was increased with the number of CMBs, and the number of CMBs ≥10 were independent predictors of ICH in acute stroke patients.

Antiplatelet therapy and future intracerebral hemorrhage in hemodialysis patients with cerebral microbleeds

The use of antiplatelet drugs is thought to increase the risk for intracerebral hemorrhage (ICH) in patients with cerebral microbleeds (CMBs). However, hemodialysis (HD) patients have a high prevalence of CMBs and diverse pathologies that require antiplatelet therapy. In this study, we investigated whether the use of antiplatelet drugs increases the risk for ICH in HD patients with CMBs. Brain magnetic resonance imaging (MRI), including T2*-weighted MRI, was performed in 179 HD patients with no history of cerebrovascular events. CMBs were detected and patients were followed prospectively with a median follow-up period of 5.2 [1.4-6.2] years. To investigate whether the influence of antiplatelet therapy on the development of ICH differs in cases with and without CMBs, the inverse probability of treatment weighting method was used, including an interaction term between the presence or absence of CMBs and use of antiplatelet drugs. As a result, CMBs were detected in 45 patients (25.1%), and antiplatelet drugs were used in 66 patients (36.9%). When the effect of antiplatelet therapy on the incidence of ICH was modified by the presence of CMBs at baseline (P for interaction <0.001), the use of antiplatelet drugs was a significant risk factor for ICH in HD patients without CMBs, but not in HD patients with CMBs. Furthermore, the burden of CMBs significantly increased the risk for ICH, but the increase in this risk was slower in antiplatelet drug users as compared to non-antiplatelet drug users (P for interaction = 0.02). The influence of antiplatelet drugs on the development of ICH differed depending on the presence or absence of CMBs. In fact, the use of antiplatelet drugs did not increase the risk for ICH in HD patients with CMBs.

Statin treatment and cerebral microbleeds: A systematic review and meta-analysis

Although statins have been associated with increased risk of spontaneous intracerebral hemorrhage, their relationship with cerebral microbleeds (CMBs) formation is poorly understood. We systematically reviewed previously published studies reporting on the association between CMBs presence and current statin use. We performed a systematic search in MEDLINE and SCOPUS databases on October 24, 2019 to identify all cohorts from randomized-controlled clinical trials or observational studies reporting on CMB prevalence and statin use. We extracted cross-sectional data on CMBs presence, as provided by each study, in association to the history of current statin use. Random effects model was used to calculate the pooled estimates. We included 7 studies (n = 3734 participants): unselected general population [n = 1965], ischemic stroke [n = 849], hemorrhagic stroke [n = 252] and patients with hypertension over the age of 60 [n = 668]. Statin use was not associated with CMBs presence in either unadjusted (OR = 1.15, 95%CI: 0.76-1.74) or adjusted analyses (OR = 1.09, 95%CI: 0.64-1.86). Statin use was more strongly related to lobar CMB presence (OR = 2.01, 95%CI: 1.48-2.72) in unadjusted analysis. The effect size of this association was consistent, but no longer statistically significant in adjusted analysis that was confined to two eligible studies (OR = 2.26, 95%CI: 0.86-5.91). Except for the analysis on the unadjusted probability of lobar CMBs presence, considerable heterogeneity was present in all other analyses (I² > 60%). Our findings suggest that statin treatment seems not to be associated with CMBs overall, but may increase the risk of lobar CMB formation. This hypothesis deserves further investigation within magnetic resonance imaging ancillary studies of randomized trials.

Advance of antithrombotic treatment in patients with cerebral microbleed

With the elder proportion increasing and the antithrombotic agents widely using as well as the newly magnetic resonance imaging sequence emerging, the detection rate of cerebral microbleed (CMB) is gradually raising in recent years. As we all know that CMB mainly reflects the severity of deeply small vessel lesions, which predicts hemorrhagic transformation. Whereby, to some patients with both CMB and remarkable antithrombotic indication, treatment becomes a dilemma. We have to face the challenge of weighing the pros and cons of both drug indication and bleeding risk when making a proper decision for patients. This study summarized recent advance on CMB diagnosis and treatment, to provide a useful reference to physicians in their clinical practice.

Low Triglyceride Levels are Associated with Unfavorable Outcomes in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND AND AIMS

The relationship between serum lipid level and clinical outcome after spontaneous intracerebral hemorrhage (ICH) remains controversial. We sought to evaluate the association of serum lipid levels with clinical outcomes in patients with ICH.

METHODS

Data on consecutive patients hospitalized with spontaneous ICH were prospectively collected from May 2005 to May 2018 and retrospectively analyzed. Following clinical and demographic data, age and gender, risk factors, serum lipid levels [total cholesterol, triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol] and the outcomes were analyzed.

RESULTS

A total of 1451 patients with ICH (mean age, 60.41 ± 12.3 years; 32.6% women) was evaluated. Although admission TG levels were associated with the outcomes at hospital discharge and 3 months in initial univariate analyses, the former association did not retain its statistical significance in multivariate logistic regression analyses adjusting for potential confounders. However, lower admission TG levels were independently associated (p = 0.045) with a higher likelihood of 12-month unfavorable outcomes (odds ratio 0.91, 95% confidence interval 0.83-0.99) in multivariate logistic regression models.

CONCLUSIONS

Low TG levels at hospital admission were an independent predictor for unfavorable long-term outcomes in patients with spontaneous ICH. The exact mechanisms of the association need further investigations.

The Impact of Cerebral Microbleeds Presence on Outcome Following Minor Stroke Treated With Antiplatelet Therapy

Background and Purpose: The relationship between cerebral microbleeds (CMBs) and prognosis in patients with ischemic stroke is still unclear. Our aim here was to verify the relationship between CMBs and functional outcomes in patients with minor ischemic stroke treated with antiplatelet therapy.

Methods: We retrospectively reviewed consecutive patients with a non-cardiogenic minor ischemic stroke (NIHSS <4 on admission) who underwent initial brain magnetic resonance imaging within the first 48 h following symptom onset. The patients were divided into two groups based on the presence or absence of CMBs and the two groups were adjusted using the pre-stroke modified Rankin scale (mRS). Poor outcome was defined as an mRS score in the 3–6 range measured 90 days after symptom onset. Logistic regression analyses were performed to determine the factors independently associated with poor outcome.

Results: A total of 240 patients (187 men, median age 66 years old) were enrolled in our study. There was a non-significant trend toward a worsening shift of 3-month mRS score distribution in the CMB group compared with the no-CMB group. Multivariate analysis revealed that the presence of CMBs was independently predictive of poor outcome (OR, 3.44; 95% CI, 1.08–10.93; P = 0.036).

Conclusion: Our findings suggest that the presence of CMBs is the predicting factor of poor outcome in minor ischemic stroke patients.

Cerebral microbleeds and acute myocardial infarction: Screening and disease progression

Introduction

Cerebral microbleeds (CMB) are associated with intracerebral haemorrhage. Therefore they may represent a concern if anticoagulant and/or antiplatelet therapy is needed. The aim of this study was to determine the prevalence of CMB in patients with acute myocardial infarction (AMI), and to follow their progression at 3 months under dual antiplatelet therapy (DAPT).

Methods

This prospective study included patients aged over 60 hospitalized in intensive cardiac care unit in our city for AMI. These patients underwent a first brain Magnetic resonance imaging (MRI) within 72 h of admission, that was repeated 3 months.

Results

108 patients were included between November 2016 and December 2018. The prevalence of CMB was 21.3%, with a female predominance of 65.2% vs 32.1% (p = 0.004). Diabetes is significantly associated with the presence of CMB, 45.5% vs 21.2% (p = 0.021). Patients with at least one acute CMB had higher haemorrhagic risk as evaluated with CRUSADE score (40.5 ± 13.6 vs 31.2 ± 14.8 (p = 0.004).

Multivariate analysis showed that only female sex was associated with the presence of a CMB on the initial MRI. On repeated MRI, an increase in CMB was observed in 6% of patients.

Our results suggest that discharge treatment with anticoagulant in combination with antiplatelet therapy may be an independent predictor of early progression of CMB.

Conclusion

Our study confirms the high prevalence of CMB in patients over 60 years with AMI. The association of anticoagulant with DAPT, 3 months after stenting, may be an independent factor of CMB progression.

Previous chronic symptomatic and asymptomatic cerebral hemorrhage in patients with acute ischemic stroke

PURPOSE

Identifying previous chronic cerebral hemorrhage (PCH), especially asymptomatic cases in patients with ischemic stroke, is essential for proper antithrombotic management. The study aimed to further clarify the prevalence of PCH and the associated factors in patients with acute ischemic stroke using multi-modal neuroimaging including susceptibility-weighted MR imaging (SWI).

METHODS

This was a retrospective cross-sectional study of 382 patients with acute ischemic stroke. All patients underwent 3.0-T MRI for cranial SWI, 1.5-T or 3.0-T conventional cranial MRI, and cranial CT. Patients found with PCH were matched 1:4 with patients without PCH. Clinical manifestation, computed tomography, conventional cranial MRI, and cranial SWI were used to determine PCH. Clinical and neuroimaging findings between the patients with symptomatic vs. asymptomatic PCH were compared.

RESULTS

Thirty-six patients (36/382, 9.4%) were determined to have had a PCH. Of these 36 patients, 17 (17/36, 47.2%, or 17/382, 4.5%) had asymptomatic PCH. Multivariable analysis showed that serum total cholesterol (OR = 0.510, 95%CI 0.312-0.832, P = 0.007), cerebral microbleeds (OR = 6.251, 95%CI 2.220-17.601, P = 0.001), and antithrombotic drugs history (OR = 3.213, 95%CI 1.018-10.145, P = 0.047) were independently associated with PCH. Asymptomatic PCH had similar clinical and neuroimaging characteristics with symptomatic PCH.

CONCLUSION

PCH is not uncommon in acute ischemic stroke patients. Total serum cholesterol, cerebral microbleeds on SWI, and history of antithrombotic drugs were independently associated with PCH in patients with acute ischemic stroke. Asymptomatic PCH, which is easier to be missed and has similar characteristics with symptomatic PCH, should draw much attention.

Restarting antiplatelet therapy after spontaneous intracerebral hemorrhage: Functional outcomes

OBJECTIVE

To compare the functional outcomes and health-related quality of life metrics of restarting vs not restarting antiplatelet therapy (APT) in patients presenting with intracerebral hemorrhage (ICH) in the ERICH (Ethnic/Racial Variations of Intracerebral Hemorrhage) study.

METHODS

Adult patients aged 18 years and older who were on APT before ICH and were alive at hospital discharge were included. Patients were dichotomized based on whether or not APT was restarted after hospital discharge. The primary outcome was a modified Rankin Scale score of 0-2 at 90 days. Secondary outcomes were excellent outcome (modified Rankin Scale score 0-1), mortality, Barthel Index, and health status (EuroQol-5 dimensions [EQ-5D] and EQ-5D visual analog scale scores) at 90 days.

RESULTS

The APT and no APT cohorts comprised 127 and 732 patients, respectively. Restarting APT was associated with lower rates of good functional outcome (36.5% vs 40.8%; p = 0.021) and lower Barthel Index scores at 90 days (p = 0.041). The 2 cohorts were then matched in a 1:1 ratio, and the matched cohorts each comprised 107 patients. No difference in primary outcome was observed between restarting vs not restarting APT (35.5% vs 43.9%; p = 0.105). There were also no differences between the secondary outcomes of the 2 cohorts.

CONCLUSION

Restarting APT in patients with ICH of mild to moderate severity after acute hospitalization is not associated with worse functional outcomes or health-related quality of life at 90 days. In patients with significant cardiovascular risk factors who experience an ICH, restarting APT remains the decision of the treating practitioner.

Cerebral Microbleeds: Imaging and Clinical Significance

Cerebral microbleeds (CMBs), also referred to as microhemorrhages, appear on magnetic resonance (MR) images as hypointense foci notably at T2*-weighted or susceptibility-weighted (SW) imaging. CMBs are detected with increasing frequency because of the more widespread use of high magnetic field strength and of newer dedicated MR imaging techniques such as three-dimensional gradient-echo T2*-weighted and SW imaging. The imaging appearance of CMBs is mainly because of changes in local magnetic susceptibility and reflects the pathologic iron accumulation, most often in perivascular macrophages, because of vasculopathy. CMBs are depicted with a true-positive rate of 48%-89% at 1.5 T or 3.0 T and T2*-weighted or SW imaging across a wide range of diseases. False-positive "mimics" of CMBs occur at a rate of 11%-24% and include microdissections, microaneurysms, and microcalcifications; the latter can be differentiated by using phase images. Compared with postmortem histopathologic analysis, at least half of CMBs are missed with premortem clinical MR imaging. In general, CMB detection rate increases with field strength, with the use of three-dimensional sequences, and with postprocessing methods that use local perturbations of the MR phase to enhance T2* contrast. Because of the more widespread availability of high-field-strength MR imaging systems and growing use of SW imaging, CMBs are increasingly recognized in normal aging, and are even more common in various disorders such as Alzheimer dementia, cerebral amyloid angiopathy, stroke, and trauma. Rare causes include endocarditis, cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, and radiation therapy. The presence of CMBs in patients with stroke is increasingly recognized as a marker of worse outcome. Finally, guidelines for adjustment of anticoagulant therapy in patients with CMBs are under development. ^© RSNA, 2018.

Cerebral small vessel disease and risk of incident stroke, dementia and depression, and all-cause mortality: A systematic review and meta-analysis

MRI features of cerebral small vessel disease (CSVD), i.e. white matter hyperintensities, lacunes, microbleeds, perivascular spaces, and cerebral atrophy, may be associated with clinical events, but the strength of these associations remains unclear. We conducted a systematic review and meta-analysis on the association between these features and incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. For the association with stroke, 36 studies were identified (number of individuals/events [n] = 38,432/4,136), for dementia 28 (n = 16,458/1,709), for depression nine (n = 9,538/1,746), and for mortality 28 (n = 23,031/2,558). Only two studies evaluated perivascular spaces; these results were not pooled. Pooled analyses showed that all other features were associated with all outcomes (hazard ratios ranged 1.22–2.72). Combinations of two features were more strongly associated with stroke than any individual feature. Individual features and combinations of CSVD features are strongly associated with incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. If these associations are causal, the strength of these associations suggests that a substantial burden of disease is attributable to CSVD.

Correlation between antiplatelet therapy in secondary prevention of acute cerebral infarction and cerebral microbleeds: A susceptibility-weighted imaging (SWI) study

OBJECTIVE

To investigate the clinical significance of antiplatelet aggregation therapy for patients diagnosed with acute cerebral infarction (ACI) complicated with the cerebral microbleeds (CMBs).

METHODS

Thirty patients with ACI and 36 patients with intracerebral hemorrhage (ICH) were included in this research. Two groups, studied by susceptibility-weighted imaging (SWI), were compared in terms of the number, location, and severity of CMBs. Then, 30 cases of ACI patients were divided into CMBs sub-group and non-CMBs sub-group. Univariate analysis between these two sub-groups was performed to determine the risk factors regarding the incidence of CMBs. For ACI patients, the number of CMBs before and after applying anti-platelet treatment were compared to examine the impacts of anti-platelet treatment on hemorrhagic transformation.

RESULTS

CMBs were found to be more prevalent and severe in ICH patients than in ACI patients. CMBs in patients with ICH were more severe than in patients with ischemic stroke (IS), which indicates that CMBs closely relate to ICH. Hypertension and leukoaraiosis were found to have significant effects on the incidence of CMBs. After anti-platelet treatment, patients with CMBs (≥5) increased the number of CMB, whereas there was no obvious effect on patients with the CMBs less than 5 or no CMBs.

CONCLUSIONS

The number of CMBs increased significantly among ACI patients with 5 or more CMBs before the anti-platelet treatment. CMBs are more frequently found in patients with hemorrhagic stroke than in patients with ischemic stroke, and more severe than the latter, which suggests that the clinical impact of higher association between the increase of the number of the CMBs and the hemorrhagic stroke.

Higher low-density lipoprotein cholesterol levels are associated with decreased mortality in patients with intracerebral hemorrhage

BACKGROUND AND AIMS

The relationship between lipoprotein levels, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and clinical outcome after intracerebral hemorrhage (ICH) remains controversial. We sought to evaluate the association of lipoprotein cholesterol levels and statin dosage with clinical and neuroimaging outcomes in patients with ICH.

METHODS

Data on consecutive patients hospitalized with spontaneous acute ICH was prospectively collected over a 5-year period and retrospectively analyzed. Demographic characteristics, clinical severity documented by NIHSS-score and ICH-score, neuroimaging parameters, pre-hospital statin use and doses, and LDL-C and HDL-C levels were recorded. Outcome events characterized were hematoma volume, hematoma expansion, in-hospital functional outcome, and in-hospital mortality.

RESULTS

A total of 672 patients with acute ICH [(mean age 61.6 ± 14.0 years, 43.6% women, median ICH score 1 (IQR: 0-2)] were evaluated. Statin pretreatment was not associated with neuroimaging or clinical outcomes. Higher LDL-C levels were associated with several markers of poor clinical outcome and in-hospital mortality. LDL-C levels were independently and negatively associated with the cubed root of hematoma volume (linear regression coefficient -0.021, 95% CI: -0.042--0.001; p = 0.049) on multiple linear regression models. Higher admission LDL-C (OR 0.88, 95% CI 0.77-0.99; p = 0.048) was also an independent predictor for decreased hematoma expansion. Higher admission LDL-C levels were independently (p < 0.001) associated with lower likelihood of in-hospital mortality (OR per 10 mg/dL increase 0.68, 95% CI: 0.57-0.80) in multivariable logistic regression models.

CONCLUSIONS

Higher LDL-C levels at hospital admission were an independent predictor for lower likelihood of hematoma expansion and decreased in-hospital mortality in patients with acute spontaneous ICH. This association requires independent confirmation.

Anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage in an intensive care unit

Intracerebral hemorrhage is one of the most common types of cerebrovascular disease in humans and often causes paralysis, a vegetative state and even death. Patients with acute intracerebral hemorrhage are frequently monitored in intensive care units (ICUs). Spontaneous intracerebral hemorrhage is associated with a higher rate of mortality and morbidity than other intracephalic diseases. The expression levels of inflammatory factors have important roles in inflammatory responses indicative of changes in a patient's condition and are therefore important in the monitoring and treatment of affected patients at the ICU as well as the development of therapeutic strategies for acute cerebral hemorrhage. The present study investigated the anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage at an ICU, and inflammatory factors and cellular changes were systematically analyzed. The plasma concentrations of inflammatory factors, including interleukin (IL)-4, IL-6, IL-8 and IL-10, were evaluated by ELISAs. The plasma concentrations of inflammatory cellular changes were detected by using flow cytometry. The results demonstrated that after Simvastatin treatment of patients with acute cerebral hemorrhage at the ICU, the plasma concentrations of IL-4, IL-6, IL-8 and IL-10 were downregulated compared with those in placebo-treated controls. In addition, Simvastatin treatment at the ICU decreased lymphocytes, granulocytes and mononuclear cells in patients with acute cerebral hemorrhage. The levels of inflammatory factors were associated with brain edema in patients with acute cerebral hemorrhage treated at the ICU. In addition, the amount of bleeding was reduced in parallel with the inflammatory cell plasma concentration of lymphocytes, granulocytes and mononuclear cells. Importantly, Simvastatin treatment produced beneficial outcomes by improving brain edema and reducing the amount of bleeding. In conclusion, the present study demonstrated the efficacy of Simvastatin in treating acute intracerebral hemorrhage and evidenced the association between inflammatory responses and the progress of affected patients at the ICU, thereby providing insight for applying effective therapies for patients with acute intracerebral hemorrhage.

Location of Cerebral Microbleeds And Their Association with Carotid Intima-media Thickness: A Community-based Study

To assess whether high cerebral microbleeds (CMBs) are associated with carotid intima-media thickness (CIMT), a marker of systemic atherosclerosis, we cross-sectionally evaluated participants from a community-based study, the I-Lan Longitudinal Aging Study. The participants' demographics and cardiovascular risk factors were determined by questionnaire and/or laboratory measurements. CIMT was measured by ultrasonography. CMBs were assessed by susceptibility-weighted-imaging on 3 T MRI. Of the 962 subjects [62.5(8.6) years, 44.2% men] included, CMBs were found in 134(14.0%) subjects. Among the subjects with identified CMB's, 85(63.4%) had deep or infratentorial (DI) and 49(36.6%) had strictly lobar(SL) CMBs. After the results were adjusted for age and sex, the analysis revealed that hypertension, hyperlipidemia, obesity, and higher triglyceride levels correlated with DI but not SL CMBs. The subjects with DI CMBs also had a higher mean CIMT and higher prevalence of top quartile CIMT. The multivariate analysis demonstrated that high CIMT (top quartile) significantly predicted the presence of DI CMBs (odds ratio = 2.1; 95% confidence interval = 1.3-3.4; P = 0.004), independent of age, sex, cardiovascular risk factors, and other cerebral small vessel diseases, lacune, and white matter hyperintensity. There was no association between CIMT and SL CMBs. Our results support that there are distinct pathogenesis in DI and SL CMBs.

Association Between Previous Use of Antiplatelet Therapy and Intracerebral Hemorrhage Outcomes

BACKGROUND AND PURPOSE

Although the use of antiplatelet therapy (APT) is associated with the risk of intracerebral hemorrhage (ICH), there are limited data on prestroke APT and outcomes, particularly among patients on combination APT (CAPT). We hypothesized that the previous use of antiplatelet agents is associated with increased mortality in ICH.

METHODS

We analyzed data of 82 576 patients with ICH who were not on oral anticoagulant therapy from 1574 Get with the Guidelines-Stroke hospitals between October 2012 and March 2016. Patients were categorized as not on APT, on single-APT (SAPT), and CAPT before hospital presentation with ICH. We described baseline characteristics, comorbidities, hospital characteristics and outcomes, overall and stratified by APT use.

RESULTS

Before the diagnosis of ICH, 65.8% patients were not on APT, 29.5% patients were on SAPT, and 4.8% patients were on CAPT. There was an overall modest increased in-hospital mortality in the APT group versus no APT group (24% versus 23%; adjusted odds ratio, 1.05; 95% confidence interval, 1.01-1.10). Although patients on SAPT and CAPT were older and had higher risk profiles in terms of comorbidities, there was no significant difference in the in-hospital mortality among patients on SAPT versus those not on any APT (23% versus 23%; adjusted odds ratio, 1.01; 95% confidence interval, 0.97-1.05). However, in-hospital mortality was higher among those on CAPT versus those not on APT (30% versus 23%; adjusted odds ratio, 1.50; 95% confidence interval, 1.39-1.63).

CONCLUSIONS

Our study suggests that among patients with ICH, previous use of CAPT, but not SAPT, was associated with higher risk for in-hospital mortality.

Intracerebral haemorrhage risk in microbleed-positive ischaemic stroke patients with atrial fibrillation: Preliminary meta-analysis of cohorts and anticoagulation decision schema

INTRODUCTION

Whether ischaemic stroke patients with atrial fibrillation (AF) and cerebral microbleeds (CMBs) on MRI can be safely anticoagulated is a hotly debated topic. We performed a systematic review and meta-analysis of published aggregate data, to investigate the risk of subsequent intracerebral haemorrhage (ICH) based on CMBs presence in this stroke population, generally considered for oral anticoagulation. We also suggest a decision-making schema for anticoagulation use in this setting.

METHODS

We searched PubMed for relevant observational studies. Random effects models with DerSimonian-Laird weights were used to investigated the association between CMBs presence at baseline MRI and ICH or ischaemic stroke during follow-up.

RESULTS

Four studies, with slightly heterogeneous design, including 990 ischaemic stroke patients were pooled in a meta-analysis (crude CMBs prevalence: 25%; 95%CI: 17%-33%). The median follow-up ranged between 17 and 37months. The future symptomatic ICH rate was 1.6% (16/990), while recurrent ischaemic stroke rate was 5.9% (58/990). Baseline CMB presence was associated with increased risk of symptomatic ICH during follow-up compared to patients without CMBs (OR: 4.16; 95%CI: 1.54-11.25; p=0.005). There was no association between CMBs presence and recurrent ischaemic stroke risk.

CONCLUSION

We have shown that the presence of CMBs in cohorts of ischaemic stroke patients, most with AF on warfarin, is associated with a 4-fold increase in subsequent ICH (but not ischaemic stroke) risk (Class III evidence). These pooled estimates are useful for future trials design. We propose a simple data-driven anticoagulation schema which awaits validation and refinement as new prospective data are accumulated.

Susceptibility-weighted imaging: current status and future directions

Susceptibility-weighted imaging (SWI) is a method that uses the intrinsic nature of local magnetic fields to enhance image contrast in order to improve the visibility of various susceptibility sources and to facilitate diagnostic interpretation. It is also the precursor to the concept of the use of phase for quantitative susceptibility mapping (QSM). Nowadays, SWI has become a widely used clinical tool to image deoxyhemoglobin in veins, iron deposition in the brain, hemorrhages, microbleeds and calcification. In this article, we review the basics of SWI, including data acquisition, data reconstruction and post-processing. In particular, the source of cusp artifacts in phase images is investigated in detail and an improved multi-channel phase data combination algorithm is provided. In addition, we show a few clinical applications of SWI for the imaging of stroke, traumatic brain injury, carotid vessel wall, siderotic nodules in cirrhotic liver, prostate cancer, prostatic calcification, spinal cord injury and intervertebral disc degeneration. As the clinical applications of SWI continue to expand both in and outside the brain, the improvement of SWI in conjunction with QSM is an important future direction of this technology. Copyright © 2016 John Wiley & Sons, Ltd.

Oral Cnm-positive Streptococcus Mutans Expressing Collagen Binding Activity is a Risk Factor for Cerebral Microbleeds and Cognitive Impairment

Cerebral microbleeds (CMBs) are an important risk factor for stroke and dementia. We have shown that the collagen binding surface Cnm protein expressed on cnm-positive Streptococcus mutans is involved in the development of CMBs. However, whether the collagen binding activity of cnm-positive S. mutans is related to the nature of the CMBs or to cognitive impairment is unclear. Two-hundred seventy nine community residents (70.0 years) were examined for the presence or absence of cnm-positive S. mutans in the saliva by PCR and collagen binding activity, CMBs, and cognitive function were evaluated. Cnm-positive S. mutans was detected more often among subjects with CMBs (p < 0.01) than those without. The risk of CMBs was significantly higher (odds ratio = 14.3) in the group with S. mutans expressing collagen binding activity, as compared to the group without that finding. Deep CMBs were more frequent (67%) and cognitive function was lower among subjects with cnm-positive S. mutans expressing collagen binding activity. This work supports the role of oral health in stroke and dementia and proposes a molecular mechanism for the interaction.

ASPREE-NEURO study protocol: A randomized controlled trial to determine the effect of low-dose aspirin on cerebral microbleeds, white matter hyperintensities, cognition, and stroke in the healthy elderly

Rationale Cerebral microbleeds seen on brain magnetic resonance imaging are markers of small vessel disease, linked to cognitive dysfunction and increased ischemic and hemorrhagic stroke risk. Observational studies suggest that aspirin use may induce cerebral microbleeds, and associated overt intracranial hemorrhage, but this has not been definitively resolved. Aims ASPREE-NEURO will determine the effect of aspirin on cerebral microbleed development over three years in healthy adults aged 70 years and over, participating in the larger 'ASPirin in Reducing Events in the Elderly (ASPREE)' primary prevention study of aspirin. Sample size Five hundred and fifty-nine participants provide 75% power (two-sided p value of 0.05) to determine an average difference of 0.5 cerebral microbleed per person after three years. Methods and design A multi-center, randomized placebo-controlled trial of 100 mg daily aspirin in participants who have brain magnetic resonance imaging at study entry, one and three years after randomization and who undergo cognitive testing at the same time points. Study outcomes The primary outcome is the number of new cerebral microbleeds on magnetic resonance imaging after three years. Secondary outcomes are the number of new cerebral microbleeds after one year, change in volume of white matter hyperintensity, cognitive function, and stroke. Discussion ASPREE-NEURO will resolve whether aspirin affects the presence and number of cerebral microbleeds, their relationship with cognitive performance, and indicate whether consideration of cerebral microbleeds alters the risk-benefit profile of aspirin in primary prevention for older people. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12613001313729.

Recurrent stroke risk and cerebral microbleed burden in ischemic stroke and TIA: A meta-analysis

Objective:

To determine associations between cerebral microbleed (CMB) burden with recurrent ischemic stroke (IS) and intracerebral hemorrhage (ICH) risk after IS or TIA.

Methods:

We identified prospective studies of patients with IS or TIA that investigated CMBs and stroke (ICH and IS) risk during ≥3 months follow-up. Authors provided aggregate summary-level data on stroke outcomes, with CMBs categorized according to burden (single, 2–4, and ≥5 CMBs) and distribution. We calculated absolute event rates and pooled risk ratios (RR) using random-effects meta-analysis.

Results:

We included 5,068 patients from 15 studies. There were 115/1,284 (9.6%) recurrent IS events in patients with CMBs vs 212/3,781 (5.6%) in patients without CMBs (pooled RR 1.8 for CMBs vs no CMBs; 95% confidence interval [CI] 1.4–2.5). There were 49/1,142 (4.3%) ICH events in those with CMBs vs 17/2,912 (0.58%) in those without CMBs (pooled RR 6.3 for CMBs vs no CMBs; 95% CI 3.5–11.4). Increasing CMB burden increased the risk of IS (pooled RR [95% CI] 1.8 [1.0–3.1], 2.4 [1.3–4.4], and 2.7 [1.5–4.9] for 1 CMB, 2–4 CMBs, and ≥5 CMBs, respectively) and ICH (pooled RR [95% CI] 4.6 [1.9–10.7], 5.6 [2.4–13.3], and 14.1 [6.9–29.0] for 1 CMB, 2–4 CMBs, and ≥5 CMBs, respectively).

Conclusions:

CMBs are associated with increased stroke risk after IS or TIA. With increasing CMB burden (compared to no CMBs), the risk of ICH increases more steeply than that of IS. However, IS absolute event rates remain higher than ICH absolute event rates in all CMB burden categories.

Increased Risk of Post-Thrombolysis Intracranial Hemorrhage in Acute Ischemic Stroke Patients with Leukoaraiosis: A Meta-Analysis

Background

Leukoaraiosis is common in patients with acute ischemic stroke. The results from many studies investigating the association between leukoaraiosis and intracranial hemorrhage after thrombolysis remain conflicting.

Methods

A meta-analysis was performed to compare the risk of post-thrombolytic intracranial hemorrhage in patients with and without leukoaraiosis. Relevant reports were identified by searching PubMed, EmBase, Cochrane Library, and ISI Web of Science through December 2015 using a combination of subjective and random terms. Eligible studies that were original articles with a clear definition of leukoaraiosis and intracranial hemorrhage were selected and analyzed. Funnel plots, Egger’s test, and Begg’s test were conducted to assess the publication bias. Sensitivity analysis was also performed to evaluate the influence of each individual study.

Results

Eleven trials that enrolled 6912 participants were included. There was a significantly increased risk for acute ischemic stroke patients with leukoaraiosis (odds ratio: 1.89, 95% confidence interval 1.51–2.37, P<0.001). Low heterogeneity and less publication bias was detected among these studies. The results of both computed tomography and magnetic resonance imaging performed on the subgroups of leukoaraiosis were significant. Furthermore, an association between leukoaraiosis and symptomatic intracranial hemorrhage was also confirmed. The odds ratios remained stable with no obvious variations on the sensitivity analysis. The limitations consisted of types of including trials and not matching some baseline variables.

Conclusions

The results of this meta-analysis show that leukoaraiosis approximately doubles the incidence of intracranial hemorrhage after thrombolytic therapy. However, it does not critically affect decision making regarding thrombolysis for patients with acute ischemic stroke. Additional investigations are required.