Cerebral microbleeds and macrobleeds: should they influence our recommendations for antithrombotic therapies?

Quantitative comparison of CSVD imaging markers between patients with possible amyloid small vessel disease and with non-amyloid small vessel disease

The spatial distribution patterns of cerebral microbleeds are associated with different types of cerebral small vessel disease (CSVD). This study aims to examine the disparities in brain imaging markers of CSVD among patients diagnosed with possible amyloid and non-amyloid small vessel disease. The head MR scans including susceptibility-weighted imaging (SWI) sequences from 351 patients at our institute were collected for analysis. CSVD imaging markers were quantified or graded across various CSVD dimensions in the patient images. Patients were categorized into the cerebral amyloid angiopathy group (CAA), hypertensive arteriopathy group (HA), or mixed small vessel disease group (Mixed), based on the spatial distribution of microbleeds. White matter lesions (WML) were segmented using an artificial neural network and assessed via a voxel-wise approach. Significant differences were observed among the three groups in several indices: microbleed count, lacune count at the centrum semiovale and basal ganglia levels, grade of enlarged perivascular space (EPVS) at the basal ganglia, and white matter lesion volume. These indices were substantially higher in the Mixed group compared to the other groups. Additionally, the incidences of cerebral hemorrhages (χ2 = 7.659, P = 0.006) and recent small subcortical infarcts (χ2 = 4.660, P = 0.031) were significantly more frequent in the HA group than in the CAA group. These results indicate that mixed spatial distribution patterns of microbleeds demonstrated the highest burden of cerebral small vessel disease. Microbleeds located in the deep brain regions were associated with a higher incidence of recent small subcortical infarcts and cerebral hemorrhages compared to those in the cortical areas.

Observation of the Therapeutic Effect of Dual Antiplatelet Therapy with Aspirin and Clopidogrel on the Incidence, Characteristics, and Outcome in Acute Ischemic Stroke Patients with Cerebral Microbleeds at a Teaching Hospital, China

Background

Cerebral microbleeds (CMBs) are an important risk factor for stroke recurrence and prognosis. However, there is no consensus on the safety of antiplatelet therapy in patients with ischemic stroke and CMBs.

Objective

This study aimed to observe the effects of dual antiplatelet therapy with aspirin and clopidogrel on bleeding conversion in patients with different degrees of CMBs.

Materials and Methods

An observational retrospective study was conducted on 160 patients with acute mild ischemic stroke admitted to the Stroke Center, Affiliated Hospital of Beihua University between March 2021 and December 2022. Patients were divided into the CMBs and non-CMB groups. The CMB group was then divided into the low, medium and high-risk groups. In two groups, all patients were administered dual antiplatelet therapy (aspirin 100 mg and clopidogrel 75 mg orally once a day for 21 days according to the Chinese Stroke Guidelines of 2018), and no other anticoagulant or antiplatelet drugs were administered during the treatment period. Head CT, National Institutes of Health Stroke Scale(NIHSS) and modified Rankin Scale (mRS) score were re-checked, and the number of bleeding conversions was calculated at 21 days.

Results

Five patients in the CMB group had intracranial hemorrhage (5/116, 4.3%), while no intracranial hemorrhage was observed in the non-CMB group. There were no differences in the conversion rate of cerebral hemorrhage, NIHSS score, or mRS score between two groups after dual antiplatelet therapy (p>0.05). The conversion rate of cerebral hemorrhage in the high-risk group was higher than that in the non-CMB group (p<0.05), but the NIHSS and mRS score showed no difference between the high-risk and non-CMB groups (p>0.05).

Conclusion

Dual antiplatelet therapy with aspirin and clopidogrel does not significantly increase the risk of bleeding transformation; however, it improves neurological recovery or long-term prognosis in patients with acute ischemic cerebral stroke complicated by low-risk and middle-risk CMBs.

Long-term outcomes of hospitalized patients with SARS-CoV-2/COVID-19 with and without neurological involvement: 3-year follow-up assessment

BACKGROUND

Acute neurological manifestation is a common complication of acute Coronavirus Disease 2019 (COVID-19) disease. This retrospective cohort study investigated the 3-year outcomes of patients with and without significant neurological manifestations during initial COVID-19 hospitalization.

METHODS AND FINDINGS

Patients hospitalized for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection between 03/01/2020 and 4/16/2020 in the Montefiore Health System in the Bronx, an epicenter of the early pandemic, were included. Follow-up data was captured up to 01/23/2023 (3 years post-COVID-19). This cohort consisted of 414 patients with COVID-19 with significant neurological manifestations and 1,199 propensity-matched patients (for age and COVID-19 severity score) with COVID-19 without neurological manifestations. Neurological involvement during the acute phase included acute stroke, new or recrudescent seizures, anatomic brain lesions, presence of altered mentation with evidence for impaired cognition or arousal, and neuro-COVID-19 complex (headache, anosmia, ageusia, chemesthesis, vertigo, presyncope, paresthesias, cranial nerve abnormalities, ataxia, dysautonomia, and skeletal muscle injury with normal orientation and arousal signs). There were no significant group differences in female sex composition (44.93% versus 48.21%, p = 0.249), ICU and IMV status, white, not Hispanic (6.52% versus 7.84%, p = 0.380), and Hispanic (33.57% versus 38.20%, p = 0.093), except black non-Hispanic (42.51% versus 36.03%, p = 0.019). Primary outcomes were mortality, stroke, heart attack, major adverse cardiovascular events (MACE), reinfection, and hospital readmission post-discharge. Secondary outcomes were neuroimaging findings (hemorrhage, active and prior stroke, mass effect, microhemorrhages, white matter changes, microvascular disease (MVD), and volume loss). More patients in the neurological cohort were discharged to acute rehabilitation (10.39% versus 3.34%, p < 0.001) or skilled nursing facilities (35.75% versus 25.35%, p < 0.001) and fewer to home (50.24% versus 66.64%, p < 0.001) than matched controls. Incidence of readmission for any reason (65.70% versus 60.72%, p = 0.036), stroke (6.28% versus 2.34%, p < 0.001), and MACE (20.53% versus 16.51%, p = 0.032) was higher in the neurological cohort post-discharge. Per Kaplan-Meier univariate survival curve analysis, such patients in the neurological cohort were more likely to die post-discharge compared to controls (hazard ratio: 2.346, (95% confidence interval (CI) [1.586, 3.470]; p < 0.001)). Across both cohorts, the major causes of death post-discharge were heart disease (13.79% neurological, 15.38% control), sepsis (8.63%, 17.58%), influenza and pneumonia (13.79%, 9.89%), COVID-19 (10.34%, 7.69%), and acute respiratory distress syndrome (ARDS) (10.34%, 6.59%). Factors associated with mortality after leaving the hospital involved the neurological cohort (odds ratio (OR): 1.802 (95% CI [1.237, 2.608]; p = 0.002)), discharge disposition (OR: 1.508 (95% CI [1.276, 1.775]; p < 0.001)), congestive heart failure (OR: 2.281 (95% CI [1.429, 3.593]; p < 0.001)), higher COVID-19 severity score (OR: 1.177 (95% CI [1.062, 1.304]; p = 0.002)), and older age (OR: 1.027 (95% CI [1.010, 1.044]; p = 0.002)). There were no group differences in radiological findings, except that the neurological cohort showed significantly more age-adjusted brain volume loss (p = 0.045) than controls. The study's patient cohort was limited to patients infected with COVID-19 during the first wave of the pandemic, when hospitals were overburdened, vaccines were not yet available, and treatments were limited. Patient profiles might differ when interrogating subsequent waves.

CONCLUSIONS

Patients with COVID-19 with neurological manifestations had worse long-term outcomes compared to matched controls. These findings raise awareness and the need for closer monitoring and timely interventions for patients with COVID-19 with neurological manifestations, as their disease course involving initial neurological manifestations is associated with enhanced morbidity and mortality.

When Atrial Fibrillation Meets Cerebral Amyloid Angiopathy: Current Evidence and Strategies

Non-valvular atrial fibrillation (AF) and cerebral amyloid angiopathy (CAA) are two common diseases in elderly populations. Despite the effectiveness of oral anticoagulant therapy in cardioembolic stroke prevention, intracranial hemorrhage represents the most serious complication of these therapies. Cerebral amyloid angiopathy is one of the main risk factors for spontaneous intracranial bleeding, and this risk is highly increased by age and concomitant antithrombotic therapies. Cerebral amyloid angiopathy can be silent for years and then manifest with clinical features simulating TIA (TIA-mimics) or stroke in AF patients, pushing clinicians to rapidly start VKAs or DOACs, thus increasing the risk of intracranial bleeding if the diagnosis of CAA was unknown. Because the cerebral amyloid angiopathy is easily diagnosed with non-contrast MRI, suspecting the disease can avoid catastrophic complications. In this review, we will provide physicians managing anticoagulant therapies with key tips to familiarize themselves with cerebral amyloid angiopathy, with a focus on the possible clinical presentations and on the diagnostic criteria.

Evaluating the role of Ginkgo biloba extract in the secondary prevention of acute ischemic stroke with cerebral microbleeds by quantitative susceptibility mapping (QSM)

BACKGROUND

EGb 761, a standardized dry extract of Ginkgo biloba leaves, has certain anti-inflammatory and thrombotic effects and can be used to treat cerebrovascular diseases.

METHODS

A total of 49 patients were randomly assigned to the Aspirin group (24 cases in Controlled group) and the Aspirin + Ginkgo biloba group (25 cases in Treatment group). The quantitative magnetic sensitivity and venous oxygen saturation of cerebral microbleeds were analyzed at admission, discharge, and after follow-up for 3 and 6 months.

RESULTS

The demographic details age, gender, and admission to NIHSS were not significantly different between the two groups (p < 0.05). Quantitative susceptibility mapping (QSM) showed that the magnetic sensitivity of patients in both groups remained stable after 3 and 6 months of follow-up, while the venous oxygen saturation of the Treatment group increased. The venous oxygen saturation at 3 and 6 months of follow-up was negatively correlated with the modified mRS grade score.

CONCLUSIONS

QSM can be used as a quantitative follow-up tool in monitoring both oxygen saturation and Magnetic susceptibility of microbleeds noninvasively in ischemic stroke patients with cerebral microbleeds. EGB combined with Aspirin can improve blood oxygen saturation in those patients and this effect is particularly significant in the long-term efficacy of secondary prevention.

Applicability of the Edinburgh CT Criteria for Lobar Intracerebral Hemorrhage Associated with Cerebral Amyloid Angiopathy

OBJECTIVE

Based on histopathology, Edinburgh diagnostic criteria were proposed to consider a nontraumatic intracerebral lobar hemorrhage (ICH) as related to cerebral amyloid angiopathy (CAA) using the initial computed tomography (CT) scan and the APOE genetic status. We aimed to externally validate the Edinburgh prediction model, excluding the APOE genotyping and based on the modified Boston criteria on the MRI for CAA diagnosis METHODS: We included patients admitted for spontaneous lobar ICH in the emergency department between 2016 and 2019 who underwent noncontrast CT scan and MRI. According to the MRI, patients were classified into the CAA group or into the non-CAA group in the case of other causes of ICH. Two neuroradiologists, blinded to the final retained diagnosis, rated each radiological feature on initial CT scan described in the Edinburgh study on initial CT scan RESULTS: A total of 102 patients were included, of whom 36 were classified in the CAA group, 46 in the non-CAA causes group and 20 of undetermined cause (excluded from the primary analysis). The Edinburgh prediction model, including finger-like projections and subarachnoid extension showed an area under receiver operating characteristic curves (AUC) of 0.760 (95% confidence interval, CI: 0.660-0.859) for the diagnosis of CAA. The AUC reached 0.808 (95% CI: 0.714-0.901) in a new prediction model integrating a third radiologic variable: the ICH cortical involvement.

CONCLUSION

Using the Boston MRI criteria as a final assessment, we provided a new external confirmation of the radiological Edinburgh CT criteria, which are directly applicable in acute settings of spontaneous lobar ICH and further proposed an original 3‑set model considering finger-like projections, subarachnoid extension, and cortical involvement that may achieve a high discrimination performance.

Clinical and neuroimaging risk factors associated with the development of intracerebral hemorrhage while taking direct oral anticoagulants

BACKGROUND AND AIMS

Intracerebral hemorrhage (ICH) associated with direct oral anticoagulant (DOAC) usage confers significant mortality/disability. We aimed to understand the clinical and neuroimaging features associated with developing ICH among DOAC users.

METHODS

Clinical and radiological data were collected from consecutive DOAC users with ICH (DOAC-ICH) and age-matched controls without ICH from a single referral center. The frequency/distribution of MRI markers of hemorrhage risk were assessed. Baseline demographics and neuroimaging markers were compared in univariate tests. Significant associations (p < 0.1) were entered into a multivariable regression model to determine predictors of ICH.

RESULTS

86 DOAC-ICH and 94 ICH-free patients were included. Diabetes, coronary artery disease, prior ischemic stroke, smoking history, and antiplatelet usage were more common in ICH patients than ICH-free DOAC users. In the neuroimaging analyses, severe white matter hyperintensities (WMHs), lacunes, cortical superficial siderosis (cSS), and cerebral microbleeds (CMBs) were more common in the ICH cohort than the ICH-free cohort. In the multivariable regression, diabetes [OR 3.53 95% CI (1.05-11.87)], prior ischemic stroke [OR 14.80 95% CI (3.33-65.77)], smoking history [OR 3.08 95% CI (1.05-9.01)], CMBs [OR 4.07 95% CI (1.45-11.39)], and cSS [OR 39.73 95% CI (3.43-460.24)] were independently associated with ICH.

CONCLUSIONS

Risk factors including diabetes, prior stroke, and smoking history as well as MRI biomarkers including CMBs and cSS are associated with ICH in DOAC users. Although screening MRIs are not typically performed prior to initiating DOAC therapy, these data suggest that patients of high-hemorrhagic risk may be identified.

A practical approach to the management of cerebral amyloid angiopathy

Cerebral amyloid angiopathy is a common small vessel disease in the elderly involving vascular amyloid-β deposition. Cerebral amyloid angiopathy is one of the leading causes of intracerebral hemorrhage and a significant contributor to age-related cognitive decline. The awareness of a diagnosis of cerebral amyloid angiopathy is important in clinical practice as it impacts decisions to use lifelong anticoagulation or nonpharmacological alternatives to anticoagulation such as left atrial appendage closure in patients who have concurrent atrial fibrillation, another common condition in older adults. This review summarizes the latest literature regarding the management of patients with sporadic cerebral amyloid angiopathy, including diagnostic criteria, imaging biomarkers for cerebral amyloid angiopathy severity, and management strategies to decrease intracerebral hemorrhage risk. In a minority of patients, the presence of cerebral amyloid angiopathy triggers an autoimmune inflammatory reaction, referred to as cerebral amyloid angiopathy-related inflammation, which is often responsive to immunosuppressive treatment in the acute phase. Diagnosis and management of cerebral amyloid angiopathy-related inflammation will be presented separately. While there are currently no effective therapeutics available to cure or halt the progression of cerebral amyloid angiopathy, we discuss emerging avenues for potential future interventions.

Treatment Approaches to Lacunar Stroke

Lacunar strokes are appropriately named for their ability to cavitate and form ponds or "little lakes" (Latin: lacune -ae meaning pond or pit is a diminutive form of lacus meaning lake). They account for a substantial proportion of both symptomatic and asymptomatic ischemic strokes. In recent years, there have been several advances in the management of large vessel occlusions. New therapies such as non-vitamin K antagonist oral anticoagulants and left atrial appendage closure have recently been developed to improve stroke prevention in atrial fibrillation; however, the treatment of small vessel disease-related strokes lags frustratingly behind. Since Fisher characterized the lacunar syndromes and associated infarcts in the late 1960s, there have been no therapies specifically targeting lacunar stroke. Unfortunately, many therapeutic agents used for the treatment of ischemic stroke in general offer only a modest benefit in reducing recurrent stroke while adding to the risk of intracerebral hemorrhage and systemic bleeding. Escalation of antithrombotic treatments beyond standard single antiplatelet agents has not been effective in long-term lacunar stroke prevention efforts, unequivocally increasing intracerebral hemorrhage risk without providing a significant benefit. In this review, we critically review the available treatments for lacunar stroke based on evidence from clinical trials. For several of the major drugs, we summarize the adverse effects in the context of this unique patient population. We also discuss the role of neuroprotective therapies and neural repair strategies as they may relate to recovery from lacunar stroke.

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

BACKGROUND

Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy.

METHODS

RESTART was a prospective, randomised, open-label, blinded-endpoint, parallel-group trial at 122 hospitals in the UK that assessed whether starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. For this prespecified subgroup analysis, consultant neuroradiologists masked to treatment allocation reviewed brain CT or MRI scans performed before randomisation to confirm participant eligibility and rate features of the intracerebral haemorrhage and surrounding brain. We followed participants for primary (recurrent symptomatic intracerebral haemorrhage) and secondary (ischaemic stroke) outcomes for up to 5 years (reported elsewhere). For this report, we analysed eligible participants with intracerebral haemorrhage according to their treatment allocation in primary subgroup analyses of cerebral microbleeds on MRI and in exploratory subgroup analyses of other features on CT or MRI. The trial is registered with the ISRCTN registry, number ISRCTN71907627.

FINDINGS

Between May 22, 2013, and May 31, 2018, 537 participants were enrolled, of whom 525 (98%) had intracerebral haemorrhage: 507 (97%) were diagnosed on CT (252 assigned to start antiplatelet therapy and 255 assigned to avoid antiplatelet therapy, of whom one withdrew and was not analysed) and 254 (48%) underwent the required brain MRI protocol (122 in the start antiplatelet therapy group and 132 in the avoid antiplatelet therapy group). There were no clinically or statistically significant hazards of antiplatelet therapy on recurrent intracerebral haemorrhage in primary subgroup analyses of cerebral microbleed presence (2 or more) versus absence (0 or 1) (adjusted hazard ratio [HR] 0·30 [95% CI 0·08-1·13] vs 0·77 [0·13-4·61]; pinteraction=0·41), cerebral microbleed number 0-1 versus 2-4 versus 5 or more (HR 0·77 [0·13-4·62] vs 0·32 [0·03-3·66] vs 0·33 [0·07-1·60]; pinteraction=0·75), or cerebral microbleed strictly lobar versus other location (HR 0·52 [0·004-6·79] vs 0·37 [0·09-1·28]; pinteraction=0·85). There was no evidence of heterogeneity in the effects of antiplatelet therapy in any exploratory subgroup analyses (all pinteraction>0·05).

INTERPRETATION

Our findings exclude all but a very modest harmful effect of antiplatelet therapy on recurrent intracerebral haemorrhage in the presence of cerebral microbleeds. Further randomised trials are needed to replicate these findings and investigate them with greater precision.

FUNDING

British Heart Foundation.

Cerebral small vessel disease: classification, clinical manifestations, diagnosis, and features of treatment

The paper considers the relevance of the problem of cerebral small vessel disease (CSVD) that is an important cause of ischemic and hemorrhagic stroke, associated with the development of cognitive impairment and complications of antithrombotic therapy. It presents briefly the current issues of etiology and pathogenesis of the disease. Sporadic non-amyloid microangiopathy, cerebral amyloid angiopathy, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) are discussed in detail from the point of view of their clinical presentation, neuroimaging, and features of therapeutic tactics. An algorithm for diagnosing CSVD in patients admitted to hospital for stroke and a differentiated approach to their treatment are proposed. Consideration of the neuroimaging manifestations of CSVD is noted to be necessary for the safe and more effective treatment of patients with cerebrovascular diseases.

A user-guided tool for semi-automated cerebral microbleed detection and volume segmentation: Evaluating vascular injury and data labelling for machine learning

Background and purpose

With extensive research efforts in place to address the clinical relevance of cerebral microbleeds (CMBs), there remains a need for fast and accurate methods to detect and quantify CMB burden. Although some computer-aided detection algorithms have been proposed in the literature with high sensitivity, their specificity remains consistently poor. More sophisticated machine learning methods appear to be promising in their ability to minimize false positives (FP) through high-level feature extraction and the discrimination of hard-mimics. To achieve superior performance, these methods require sizable amounts of precisely labelled training data. Here we present a user-guided tool for semi-automated CMB detection and volume segmentation, offering high specificity for routine use and FP labelling capabilities to ease and expedite the process of generating labelled training data.

Materials and methods

Existing computer-aided detection methods reported by our group were extended to include fully-automated segmentation and user-guided CMB classification with FP labelling. The algorithm's performance was evaluated on a test set of ten patients exhibiting radiotherapy-induced CMBs on MR images.

Results

The initial algorithm's base sensitivity was maintained at 86.7%. FP's were reduced to inter-rater variations and segmentation results were in 98% agreement with ground truth labelling. There was an approximate 5-fold reduction in the time users spent evaluating CMB burden with the algorithm versus without computer aid. The Intra-class Correlation Coefficient for inter-rater agreement was 0.97 CI[0.92,0.99].

Conclusions

This development serves as a valuable tool for routine evaluation of CMB burden and data labelling to improve CMB classification with machine learning. The algorithm is available to the public on GitHub (https://github.com/LupoLab-UCSF/CMB_labeler).

Microbleeds in ischemic vs hemorrhagic strokes on novel oral anticoagulants

OBJECTIVES

To identify differences in clinical characteristics and severity of cerebral small vessel disease (CSVD) including cerebral microbleeds (CMBs), between patients suffering ischemic stroke (IS) or intracerebral hemorrhage (ICH) while taking novel (non-vitamin K antagonists) oral anticoagulants (NOACs).

METHODS

Multicenter, prospective, observational cohort study performed at 38 centers between 2012 and 2015. We compared demographics, comorbidity, and functional status (before and after stroke) between NOAC-IS and NOAC-ICH patients. Extent of white matter lesions (WML), and location and counts of CMBs were analyzed in a subgroup of patients for whom MRI including hemorrhage-sensitive sequences was available.

RESULTS

A total of 351 patients were included (290 NOAC-IS, 61 NOAC-ICH). Functional status was worse in NOAC-ICH patients before and after stroke. No significant differences were found for demographic variables and cardiovascular comorbidity. In the subgroup with available MRI (n = 116), the proportion of patients with at least one CMB was higher in NOAC-ICH than in NOAC-IS (15/19 [79%] vs 36/97 [37%], P < .001), as was the absolute number of CMBs (median 5 [IQR 1-24] vs 0 [0-1], P < .001). WML were more extensive in NOAC-ICH than in NOAC-IS patients. Adjusted for WML, logistic regression analysis showed higher odds of NOAC-ICH in patients with CMB than without (OR 5.60 [1.64-19.14], P = .006).

CONCLUSIONS

Patients with NOAC-ICH have similar clinical characteristics but a higher prevalent burden of CSVD compared to NOAC-IS. The role of neuroimaging in selection of patients for anticoagulation with NOAC requires further investigation in longitudinal studies.

Updates on Prevention of Hemorrhagic and Lacunar Strokes

Intracerebral hemorrhage (ICH) and lacunar infarction (LI) are the major acute clinical manifestations of cerebral small vessel diseases (cSVDs). Hypertensive small vessel disease, cerebral amyloid angiopathy, and hereditary causes, such as Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), constitute the three common cSVD categories. Diagnosing the underlying vascular pathology in these patients is important because the risk and types of recurrent strokes show significant differences. Recent advances in our understanding of the cSVD-related radiological markers have improved our ability to stratify ICH risk in individual patients, which helps guide antithrombotic decisions. There are general good-practice measures for stroke prevention in patients with cSVD, such as optimal blood pressure and glycemic control, while individualized measures tailored for particular patients are often needed. Antithrombotic combinations and anticoagulants should be avoided in cSVD treatment, as they increase the risk of potentially fatal ICH without necessarily lowering LI risk in these patients. Even when indicated for a concurrent pathology, such as nonvalvular atrial fibrillation, nonpharmacological approaches should be considered in the presence of cSVD. More data are emerging regarding the presentation, clinical course, and diagnostic markers of hereditary cSVD, allowing accurate diagnosis, and therefore, guiding management of symptomatic patients. When suspicion for asymptomatic hereditary cSVD exists, the pros and cons of prescribing genetic testing should be discussed in detail in the absence of any curative treatment. Recent data regarding diagnosis, risk stratification, and specific preventive approaches for both sporadic and hereditary cSVDs are discussed in this review article.

Assessment of cerebral microbleeds by susceptibility-weighted imaging at 3T in patients with end-stage organ failure

PURPOSE

Cerebral microbleeds (CMBs) are small rounded lesions representing cerebral hemosiderin deposits surrounded by macrophages that results from previous microhemorrhages. The aim of this study was to review the distribution of cerebral microbleeds in patients with end-stage organ failure and their association with specific end-stage organ failure risk factors.

MATERIALS AND METHODS

Between August 2015 and June 2017, we evaluated 15 patients, 9 males, and 6 females, (mean age 65.5 years). Patients population was subdivided into three groups according to the organ failure: (a) chronic kidney failure (n = 8), (b) restrictive cardiomyopathy undergoing heart transplantation (n = 1), and (c) end-stage liver failure undergoing liver transplantation (n = 6). The MR exams were performed on a 3T MR unit and the SWI sequence was used for the detection of CMBs. CMBs were subdivided in supratentorial lobar distributed, supratentorial non-lobar distributed, and infratentorial distributed.

RESULTS

A total of 91 microbleeds were observed in 15 patients. Fifty-nine CMBs lesions (64.8%) had supratentorial lobar distribution, 17 CMBs lesions (18.8%) had supratentorial non-lobar distribution and the remaining 15 CMBs lesions (16.4%) were infratentorial distributed. An overall predominance of supratentorial multiple lobar localizations was found in all types of end-stage organ failure. The presence of CMBs was significantly correlated with age, hypertension, and specific end-stage organ failure risk factors (p < 0.001).

CONCLUSIONS

CMBs are mostly founded in supratentorial lobar localization in end-stage organ failure. The improved detection of CMBs with SWI sequences may contribute to a more accurate identification of patients with cerebral risk factors to prevent complications during or after the organ transplantation.

Severity of arterial defects in the retina correlates with the burden of intracerebral haemorrhage in COL4A1-related stroke

Mutations in the α1 (COL4A1) or α2 (COL4A2) chains of collagen type IV, a major component of the vascular basement membrane, cause intracerebral haemorrhages with variable expressivity and reduced penetrance by mechanisms that remain poorly understood. Here we sought to investigate the cellular mechanisms of COL4A1-related intracerebral haemorrhage and identify a marker for haemorrhage risk stratification. A combination of histological, immunohistochemical, and electron microscopy analyses were used to analyse the brain parenchyma, cerebrovasculature, and retinal vessels of mice expressing the disease-causing COL4A1 p.G498V mutation. Mutant mice developed cerebral microhaemorrhages and macroscopic haemorrhages (macrohaemorrhages), the latter with reduced penetrance, mimicking the human disease. Microhaemorrhages that occurred in early postnatal life were associated with a transient, generalized increase in blood-brain barrier permeability at the level of capillaries. Macrohaemorrhages, which occurred later in life, originated from deep brain arteries with focal loss of smooth muscle cells. Similar smooth muscle cell loss was detected in retinal arteries, and a time-course analysis of arterial lesions showed that smooth muscle cells are recruited normally in arterial wall during development, but undergo progressive apoptosis-mediated degeneration. By assessing in parallel the extent of these retinal arterial lesions and the presence/absence of macrohaemorrhages, we found that the arterial lesion load in the retina is strongly correlated with the burden of macrohaemorrhages. We conclude that microhaemorrhages and macrohaemorrhages are driven by two distinct mechanisms. Moreover, smooth muscle cell degeneration is a critical factor underlying the partial penetrance of COL4A1-related macrohaemorrhages, and retinal imaging is a promising tool for identifying high-risk patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Atrial Fibrillation for the Neurologist: Preventing both Ischemic and Hemorrhagic Strokes

PURPOSE OF REVIEW

This review aims to help neurologists managing atrial fibrillation (AF) patients who had an ischemic stroke and/or with intracranial hemorrhage (ICH) markers, therefore at high embolic/hemorrhagic risks.

RECENT FINDINGS

Implantable loop recorders have substantially improved the accuracy of AF detection. Recent research yielded a set of powerful neuroimaging markers that can stratify ICH risk. Direct oral anticoagulants (DOAC) are easier to use with a lower ICH risk than warfarin in a general AF population. Finally, the FDA-approved left atrial appendage closure (LAAC) with the WATCHMAN device provides an option without the need for life-long anticoagulation. In this review, we introduce the concept of preventing both ischemic and hemorrhagic strokes in AF patients through accurate AF diagnosis and stratification of both embolic and ICH risks. LAAC can be considered in patients at higher hemorrhagic risks while warfarin/DOAC use should be individualized in the majority of AF patients at a low risk of bleeding.

Prospective Study of Fasting Blood Glucose and Intracerebral Hemorrhagic Risk

BACKGROUND AND PURPOSE

Although diabetes mellitus is an established independent risk factor for ischemic stroke, the association between fasting blood glucose and intracerebral hemorrhage (ICH) is limited and inconsistent. The objective of the current study was to examine the potential impact of long-term fasting blood glucose concentration on subsequent risk of ICH.

METHODS

This prospective study included 96 110 participants of the Kailuan study, living in Kailuan community, Tangshan city, China, who were free of cardiovascular diseases and cancer at baseline (2006). Fasting blood glucose concentration was measured in 2006, 2008, 2010, and 2012. Updated cumulative average fasting blood glucose concentration was used as primary exposure of the current study. Incident ICH from 2006 to 2015 was confirmed by review of medical records.

RESULTS

During 817 531 person-years of follow-up, we identified 755 incident ICH cases. The nadir risk of ICH was observed at fasting blood glucose concentration of 5.3 mmol/L. The adjusted hazard ratios and their 95% confidence intervals (CIs) of ICH were 1.59 (95% CI, 1.26-2.02) for diabetes mellitus or fasting blood glucose ≥7.00 mmol/L, 1.31 (95% CI, 1.02-1.69) for impaired fasting blood glucose (fasting blood glucose, 6.10-6.99 mmol/L), 0.98 (95% CI, 0.78-1.22) for fasting blood glucose 5.60 to 6.09 mmol/L, and 2.04 (95% CI, 1.23-3.38) for hypoglycemia (fasting blood glucose, <4.00 mmol/L), comparing with normal fasting blood glucose 4.00 to 5.59 mmol/L. The results persisted after excluding individuals who used hypoglycemic, aspirin, antihypertensive agents, or anticoagulants, and those with intracerebral hemorrhagic cases occurred in the first 2 years of follow-up.

CONCLUSIONS

In this large community-based cohort, low (<4.0 mmol/L) and high (≥6.1 mmol/L) fasting blood glucose concentrations were associated with higher risk of incident ICH, relative to fasting blood glucose concentrations of 4.00 to 6.09 mmol/L.

Initial Investigation into Microbleeds and White Matter Signal Changes following Radiotherapy for Low-Grade and Benign Brain Tumors Using Ultra-High-Field MRI Techniques

BACKGROUND AND PURPOSE

External beam radiation therapy is a common treatment for many brain neoplasms. While external beam radiation therapy adheres to dose limits to protect the uninvolved brain, areas of high dose to normal tissue still occur. Patients treated with chemoradiotherapy can have adverse effects such as microbleeds and radiation necrosis, but few studies exist of patients treated without chemotherapy.

MATERIALS AND METHODS

Ten patients were treated for low-grade or benign neoplasms with external beam radiation therapy only and scanned within 12-36 months following treatment with a 7T MR imaging scanner. A multiecho gradient-echo sequence was acquired and postprocessed into SWI, quantitative susceptibility mapping, and apparent transverse relaxation maps. Six patients returned for follow-up imaging approximately 18 months following their first research scan and were imaged with the same techniques.

RESULTS

At the first visit, 7/10 patients had microbleeds evident on SWI, quantitative susceptibility mapping, and apparent transverse relaxation. All microbleeds were within a dose region of >45 Gy. Additionally, 4/10 patients had asymptomatic WM signal changes evident on standard imaging. Further analysis with our technique revealed that these lesions were venocentric, suggestive of a neuroinflammatory process.

CONCLUSIONS

There exists a potential for microbleeds in patients treated with external beam radiation therapy without chemotherapy. This finding is of clinical relevance because it could be a precursor of future neurovascular disease and indicates that additional care should be taken when using therapies such as anticoagulants. Additionally, the appearance of venocentric WM lesions could be suggestive of a neuroinflammatory mechanism that has been suggested in diseases such as MS. Both findings merit further investigation in a larger population set.

Cerebral Amyloid Angiopathy: Diagnosis, Clinical Implications, and Management Strategies in Atrial Fibrillation

With an aging population, clinicians are more frequently encountering patients with atrial fibrillation who are also at risk of intracerebral hemorrhage due to cerebral amyloid angiopathy, the result of β-amyloid deposition in cerebral vessels. Cerebral amyloid angiopathy is common among elderly patients, and is associated with an increased risk of intracerebral bleeding, especially with the use of anticoagulation. Despite this association, this entity is absent in current risk-benefit analysis models, which may result in underestimation of the chance of bleeding in the subset of patients with this disease. Determining the presence and burden of cerebral amyloid angiopathy is particularly important when planning to start or restart anticoagulation after an intracerebral hemorrhage. Given the lack of randomized trial data to guide management strategies, we discuss a heart-brain team approach that includes clinician-patient shared decision making for the use of pharmacologic and nonpharmacologic approaches to diminish stroke risk.

Imaging features of intracerebral hemorrhage with cerebral amyloid angiopathy: Systematic review and meta-analysis

BACKGROUND

We sought to summarize Computed Tomography (CT)/Magnetic Resonance Imaging (MRI) features of intracerebral hemorrhage (ICH) associated with cerebral amyloid angiopathy (CAA) in published observational radio-pathological studies.

METHODS

In November 2016, two authors searched OVID Medline (1946-), Embase (1974-) and relevant bibliographies for studies of imaging features of lobar or cerebellar ICH with pathologically proven CAA ("CAA-associated ICH"). Two authors assessed studies' diagnostic test accuracy methodology and independently extracted data.

RESULTS

We identified 22 studies (21 cases series and one cross-sectional study with controls) of CT features in 297 adults, two cross-sectional studies of MRI features in 81 adults and one study which reported both CT and MRI features in 22 adults. Methods of CAA assessment varied, and rating of imaging features was not masked to pathology. The most frequently reported CT features of CAA-associated ICH in 21 case series were: subarachnoid extension (pooled proportion 82%, 95% CI 69-93%, I2 = 51%, 12 studies) and an irregular ICH border (64%, 95% CI 32-91%, I2 = 85%, five studies). CAA-associated ICH was more likely to be multiple on CT than non-CAA ICH in one cross-sectional study (CAA-associated ICH 7/41 vs. non-CAA ICH 0/42; χ2 = 7.8, p = 0.005). Superficial siderosis on MRI was present in 52% of CAA-associated ICH (95% CI 39-65%, I2 = 35%, 3 studies).

CONCLUSIONS

Subarachnoid extension and an irregular ICH border are common imaging features of CAA-associated ICH, but methodologically rigorous diagnostic test accuracy studies are required to determine the sensitivity and specificity of these features.

Florbetapir-PET to diagnose cerebral amyloid angiopathy: A prospective study

OBJECTIVE

We hypothesized that florbetapir, a Food and Drug Administration-approved PET tracer, could distinguish cerebral amyloid angiopathy (CAA)-related intracerebral hemorrhage (ICH) from hypertensive ICH (HTN-ICH).

METHODS

We prospectively enrolled survivors of primary ICH related to probable CAA (per Boston Criteria, n = 10) and HTN-ICH (n = 9) without dementia. All patients underwent florbetapir-PET and multimodal MRI, and patients with CAA had additional Pittsburgh compound B (PiB) PET. Amyloid burden was assessed quantitatively (standard uptake value ratio [SUVR]) and visually classified as positive or negative.

RESULTS

The CAA and HTN-ICH groups had similar age (66.9 vs 67.1), sex, and leukoaraiosis volumes (31 vs 30 mL, all p > 0.8). Florbetapir uptake and PiB retention strongly correlated in patients with CAA both globally within cerebral cortex (r = 0.96, p < 0.001) and regionally in lobar cortices (all r > 0.8, all p ≤ 0.01). Mean global cortical florbetapir uptake was substantially higher in CAA than HTN-ICH (SUVR: 1.41 ± 0.17 vs 1.15 ± 0.08, p = 0.001), as was mean occipital SUVR (1.44 ± 0.12 vs 1.17 ± 0.08, p < 0.001), even after correcting for global SUVR (p = 0.03). Visual rating for positive/negative florbetapir demonstrated perfect interrater agreement (k = 1) and was positive for all 10 patients with CAA vs 1 of 9 HTN-ICH patients (sensitivity 100%, specificity 89%).

CONCLUSIONS

Florbetapir appears to label vascular amyloid in patients with CAA-related ICH. The approved florbetapir binary visual reading method can have diagnostic value in appropriate clinical settings.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that florbetapir-PET provides a sensitivity of 100% (95% confidence interval [CI] 66%-100%) and specificity of 89% (95% CI 51%-99%) for determination of probable CAA among cognitively normal patients.

Brain health and shared risk factors for dementia and stroke

Impaired brain health encompasses a range of clinical outcomes, including stroke, dementia, vascular cognitive impairment, cognitive ageing, and vascular functional impairment. Conditions associated with poor brain health represent leading causes of global morbidity and mortality, with projected increases in public health burden as the population ages. Many vascular risk factors are shared predictors for poor brain health. Moreover, subclinical brain MRI markers of vascular damage are risk factors shared between stroke and dementia, and can be used for risk stratification and early intervention. The broad concept of brain health has resulted in a conceptual shift from vascular risk factors to determinants of brain health. Global campaigns to reduce cardiovascular diseases by targeting modifiable risk factors are necessary and will have a broad impact on brain health. Research is needed on the distinct and overlapping aetiologies of brain health conditions, and to define MRI markers to help clinicians identify patients who will benefit from aggressive prevention measures.

Current perspectives on the use of intravenous recombinant tissue plasminogen activator (tPA) for treatment of acute ischemic stroke

In 1995, the NINDS (National Institute of Neurological Disorders and Stroke) tPA (tissue plasminogen activator) Stroke Study Group published the results of a large multicenter clinical trial demonstrating efficacy of intravenous tPA by revealing a 30% relative risk reduction (absolute risk reduction 11%-15%) compared with placebo at 90 days in the likelihood of having minimal or no disability. Since approval in 1996, tPA remains the only drug treatment for acute ischemic stroke approved by the US Food and Drug Administration. Over the years, an abundance of research and clinical data has supported the safe and efficacious use of intravenous tPA in all eligible patients. Despite such supporting data, it remains substantially underutilized. Challenges to the utilization of tPA include narrow eligibility and treatment windows, risk of symptomatic intracerebral hemorrhage, perceived lack of efficacy in certain high-risk subgroups, and a limited pool of neurological and stroke expertise in the community. With recent US census data suggesting annual stroke incidence will more than double by 2050, better education and consensus among both the medical and lay public are necessary to optimize the use of tPA for all eligible stroke patients. Ongoing and future research should continue to improve upon the efficacy of tPA through more rapid stroke diagnosis and treatment, refinement of advanced neuroimaging and stroke biomarkers, and successful demonstration of alternative means of reperfusion.