Acute cerebral microbleeds at the edge of lacunar strokes: cause or result

We investigated the pathogenic relationship between cerebral microbleeds and lacunar strokes. Two cases of lacunar strokes in the region of the basal ganglia, a 72-year-old man and a 67-year-old man, were studied; both cases showed cerebral microbleeds in the stroke areas. The cerebral microbleeds were surrounded by oedema, and the oedema faded out over time, suggesting the cerebral microbleeds had developed acutely. The cerebral microbleeds were located at the ventrolateral edge of the lacunar infarctions, and the locations appeared to be at or near the sites of occlusion of the lenticulostriatal branches. Although a cerebral microbleed and a lacunar infarction may be two unrelated events on juxtapositioned vessels, or a cerebral microbleed may be haemorrhagic conversion of an infarction, a cerebral microbleed could cause an occlusion of the arterial branch, leading to lacunar infarction of its supplying territories.

Caveolin-1 Alleviates Angiotensin Ⅱ Induced Endothelial Injury and Cerebral Microbleed Via Mitochondrial Protection

Cerebral microbleeds are a manifestation of cerebral small vessel disease (CSVD) and a predictor of cerebral hemorrhage. However, the causes of cerebral microbleeds remain unclear. Research on the mechanism of cerebral microbleeds may provide new ideas for the treatment of CSVD. In a mouse model, we show cerebral microbleeds and cognitive impairment with increasing expression of caveolin-1 (Cav-1). Mechanistically, in an in vitro study, we find that Cav-1 knockdown significantly affects the mitochondrial pathway in the cytoplasm and decreases the endothelial viability. Moreover, Cav-1 knockdown induces mitochondrial membrane potential (MMP) depolarization and mitochondria reactive oxygen species (ROS) production. By contrast, overexpression of Cav-1 alleviates the decrease of cell viability, MMP depolarization and mitochondria ROS production induced by angiotensin Ⅱ (Ang Ⅱ). Furthermore, Cav-1 activation significantly improves cerebral microbleeds and cognitive impairment in CSVD mice. We identify Cav-1 as an endogenous protective molecule via mitochondrial protection, and activation of Cav-1 resists microbleeds and cognitive impairment in an animal model of CSVD. Cav-1 might be a candidate therapeutic target for CSVD.

Age, Sex and Cerebral Microbleed Effects On White Matter Degradation After Traumatic Brain Injury

Mild traumatic brain injury (mTBI) affects white matter (WM) integrity and accelerates neurodegeneration. This study assesses the effects of age, sex, and cerebral microbleed (CMB) load as predictors of WM integrity in 70 subjects aged 18-77 imaged acutely and ~6 months after mTBI using diffusion tensor imaging (DTI). Two-tensor unscented Kalman tractography was used to segment and cluster 73 WM structures and to map changes in their mean fractional anisotropy (FA), a surrogate measure of WM integrity. Dimensionality reduction of mean FA feature vectors was implemented using principal component (PC) analysis, and two prominent PCs were used as responses in a multivariate analysis of covariance. Acutely and chronically, older age was significantly associated with lower FA (F2,65 = 8.7, p < .001, η2 = 0.2; F2,65 = 12.3, p < .001, η2 = 0.3, respectively), notably in the corpus callosum and in dorsolateral temporal structures, confirming older adults’ WM vulnerability to mTBI. Chronically, sex was associated with mean FA (F2,65 = 5.0, p = 0.01, η2 = 0.1), indicating males’ greater susceptibility to WM degradation. Acutely, a significant association was observed between CMB load and mean FA (F2,65 = 5.1, p = 0.009, η2 = 0.1), suggesting that CMBs reflect the acute severity of diffuse axonal injury. Together, these findings indicate that older age, male sex, and CMB load are risk factors for WM degeneration. Future research should examine how sex- and age-mediated WM degradation lead to cognitive decline and connectome degeneration after mTBI.

New Insights in Addressing Cerebral Small Vessel Disease: Association With the Deep Medullary Veins

ObjectiveTo assess the suitability of deep medullary vein visibility in susceptibility weighted imaging—magnetic resonance imaging studies as a method for the diagnosis and evaluation of cerebral small vessel disease progression.MethodsA total of 92 patients with CSVD were enrolled and baseline clinical and imaging data were reviewed retrospectively. Neuroimaging biomarkers of CSVD including high-grade white matter hyperintensity (HWMH), cerebral microbleed (CMB), enlarged perivascular space (PVS), and lacunar infarct (LI) were identified and CSVD burden was calculated. Cases were grouped accordingly as mild, moderate, or severe. The DMV was divided into six segments according to the regional anatomy. The total DMV score (0–18) was calculated as the sum of the six individual segmental scores, which ranged from 0 to 3, for a semi-quantitative assessment of the DMV based on segmental continuity and visibility.ResultsThe DMV score was independently associated with the presence of HWMH, PVS, and LI (P < 0.05), but not with presence and absence of CMB (P > 0.05). Correlation between the DMV score and the CSVD burden was significant (P < 0.05) [OR 95% C.I., 1.227 (1.096–1.388)].ConclusionThe DMV score was associated with the presence and severity of CSVD.

Antiplatelet therapy may be safe in ischemic stroke patients with cerebral microbleed

Objective We examined whether antiplatelet therapy is safe for ischemic stroke patients with cerebral microbleed. Methods We retrospectively analyzed ischemic stroke patients admitted to our hospital from 2015 to 2018. Baseline information was extracted from the computerized database. Adverse events, including symptomatic cerebral hemorrhage, recurrent cerebral infarction, and death, were collected by phone. Results A total of 184 ischemic stroke patients were examined, including 106 with and 78 without cerebral microbleed. No patient experienced symptomatic cerebral hemorrhage after discharge. Patients with cerebral microbleed had a higher prevalence of hypertension (92% vs 74%) and suffered from more serious leukoaraiosis (3.0 ± 1.7 vs 1.3 ± 1.4 points on the Fazekas scale). Leukoaraiosis scores were correlated with the number of cerebral microbleeds (r = 0.42). Conclusions Antiplatelet therapy may be safe for ischemic stroke patients with cerebral microbleed. The risk-benefit ratio should be carefully evaluated before withholding antiplatelet therapy.

Combining Imaging and Genetics to Predict Recurrence of Anticoagulation-Associated Intracerebral Hemorrhage

Background and Purpose: For survivors of oral anticoagulation therapy (OAT)–associated intracerebral hemorrhage (OAT-ICH) who are at high risk for thromboembolism, the benefits of OAT resumption must be weighed against increased risk of recurrent hemorrhagic stroke. The ε2/ε4 alleles of the apolipoprotein E ( APOE ) gene, MRI-defined cortical superficial siderosis, and cerebral microbleeds are the most potent risk factors for recurrent ICH. We sought to determine whether combining MRI markers and APOE genotype could have clinical impact by identifying ICH survivors in whom the risks of OAT resumption are highest. Methods: Joint analysis of data from 2 longitudinal cohort studies of OAT-ICH survivors: (1) MGH-ICH study (Massachusetts General Hospital ICH) and (2) longitudinal component of the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage). We evaluated whether MRI markers and APOE genotype predict ICH recurrence. We then developed and validated a combined APOE -MRI classification scheme to predict ICH recurrence, using Classification and Regression Tree analysis. Results: Cortical superficial siderosis, cerebral microbleed, and APOE ε2/ε4 variants were independently associated with ICH recurrence after OAT-ICH (all P <0.05). Combining APOE genotype and MRI data resulted in improved prediction of ICH recurrence (Harrell C: 0.79 versus 0.55 for clinical data alone, P =0.033). In the MGH (training) data set, CSS, cerebral microbleed, and APOE ε2/ε4 stratified likelihood of ICH recurrence into high-, medium-, and low-risk categories. In the ERICH (validation) data set, yearly ICH recurrence rates for high-, medium-, and low-risk individuals were 6.6%, 2.5%, and 0.9%, respectively, with overall area under the curve of 0.91 for prediction of recurrent ICH. Conclusions: Combining MRI and APOE genotype stratifies likelihood of ICH recurrence into high, medium, and low risk. If confirmed in prospective studies, this combined APOE -MRI classification scheme may prove useful for selecting individuals for OAT resumption after ICH.