Statins and perihemorrhagic edema in patients with spontaneous intracerebral hemorrhage

Simvastatin Upregulates Lipoxin A4 and Accelerates Neuroinflammation Resolution After Intracerebral Hemorrhage

BACKGROUND

Previous studies have demonstrated that statins can relieve inflammatory brain injury after intracerebral hemorrhage (ICH), but the mechanisms remain poorly characterized. This study aims to test whether simvastatin exerts an anti-inflammatory effect by regulating the proresolving mediators.

METHODS

First, male Sprague-Dawley rats had an injection of 200 μL autologous blood. Then, rats were randomly divided into groups treated with simvastatin (i.p. 2 mg/kg) or vehicle. Next, all rats underwent pro-resolving mediator lipoxin A4 (LXA4) level detection, flow cytometric, immunofluorescence, brain edema measurement, neurological scoring and western blot analysis.

RESULTS

We found that simvastatin significantly increased the plasma level of LXA4, an endogenous formyl-peptide receptor 2 (FPR2) agonist, in the early stage of ICH. Consistent with the effect of simvastatin, exogenous LXA4 administration also promoted apoptosis of the circulating neutrophils, reduced neutrophils brain infiltration, and ameliorated inflammatory brain injury after ICH. In addition, similar to simvastatin, exogenous LXA4 markedly decreased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK) and the apoptosis-related proteins myeloid cell leukemia 1(Mcl-1)/Bax ratio (a decreased ratio represents the induction of apoptosis) in circulating neutrophils isolated from ICH rats. Notably, all of the aforementioned effects of simvastatin on ICH were significantly abolished by Boc-2, a selective antagonist of FPR2. Moreover, simvastatin led to a similar Mcl-1/Bax ratio reduction as SB203580 (a p38 MAPK inhibitor), but it was abolished by P79350 (a p38 MAPK agonist).

CONCLUSION

Collectively, these results suggest that simvastatin ameliorates ICH-mediated inflammatory brain injury, possibly by upregulating the level of pro-resolving mediator LXA4 and further stimulating the FPR2/p38 MAPK signaling pathway.

3D slicer-based calculation of hematoma irregularity index for predicting hematoma expansion in intracerebral hemorrhage

BACKGROUND

Irregular hematoma is considered as a risk sign of hematoma expansion. The aim of this study was to quantify hematoma irregularity with computed tomography based on 3D Slicer.

METHODS

Patients with spontaneous intracerebral hemorrhage who underwent an initial and subsequent non-contrast computed tomography (CT) at a single medical center between January 2019 to January 2020 were retrospectively identified. The Digital Imaging and Communication in Medicine (DICOM) standard images were loaded into the 3D Slicer, and the surface area (S) and volume (V) of hematoma were calculated. The hematoma irregularity index (HII) was defined as [Formula: see text]. Logistic regression analyses and receiver operating characteristic (ROC) curve analysis were performed to assess predictive performance of HII.

RESULTS

The enrolled patients were divided into those with hematoma enlargement (n = 36) and those without the enlargement (n = 57). HII in hematoma expansion group was 130.4 (125.1-140.0), and the index in non-enlarged hematoma group was 118.6 (113.5-122.3). There was significant difference in HII between the two groups (P < 0.01). Multivariate logistic regression analysis revealed that the HII was significantly associated with hematoma expansion before (odds ratio = 1.203, 95% confidence interval [CI], 1.115-1.298; P < 0.001) and after adjustment for age, hematoma volume, Glasgow Coma Scale score (odds ratio = 1.196, 95% CI, 1.102-1.298, P < 0.001). The area under the ROC curve was 0.86 (CI, 0.78-0.93, P < 0.01), and the best cutoff of HII for predicting hematoma growth was 123.8.

CONCLUSION

As a quantitative indicator of irregular hematoma, HII can be calculated using the 3D Slicer. And the HII was independently correlated with hematoma expansion.

Microglia Phenotype and Intracerebral Hemorrhage: A Balance of Yin and Yang

Intracerebral hemorrhage (ICH) features extremely high rates of morbidity and mortality, with no specific and effective therapy. And local inflammation caused by the over-activated immune cells seriously damages the recovery of neurological function after ICH. Fortunately, immune intervention to microglia has provided new methods and ideas for ICH treatment. Microglia, as the resident immune cells in the brain, play vital roles in both tissue damage and repair processes after ICH. The perihematomal activated microglia not only arouse acute inflammatory responses, oxidative stress, excitotoxicity, and cytotoxicity to cause neuron death, but also show another phenotype that inhibit inflammation, clear hematoma and promote tissue regeneration. The proportion of microglia phenotypes determines the progression of brain tissue damage or repair after ICH. Therefore, microglia may be a promising and imperative therapeutic target for ICH. In this review, we discuss the dual functions of microglia in the brain after an ICH from immunological perspective, elaborate on the activation mechanism of perihematomal microglia, and summarize related therapeutic drugs researches.

Upregulation of AQP4 Improves Blood-Brain Barrier Integrity and Perihematomal Edema Following Intracerebral Hemorrhage

In intracerebral hemorrhage (ICH), delayed secondary neural damages largely occur from perihematomal edema (PHE) resulting from the disruption of the blood-brain barrier (BBB). PHE is often considered the principal cause of morbidity and mortality in patients with ICH. Nevertheless, the main cellular mechanism as well as the specific BBB component involved in the formation of PHE after ICH remains elusive. Herein, we evaluated the role of AQP4, a water channel expressed on the astrocytes of the BBB, in the formation of PHE in ICH. The static and dynamic functions of the BBB were evaluated by analyzing the microstructure and leakage assay. Protein changes in the PHE lesion were analyzed and the control mechanism of AQP4 expression by reactive oxygen species was also investigated. Delayed PHE formation due to BBB disruption after ICH was confirmed by the decreased coverage of multiple BBB components and increased dynamic leakages. Microstructure assay showed that among the BBB components, AQP4 showed a markedly decreased expression in the PHE lesions. The decrease in AQP4 was due to microenvironmental ROS derived from the hemorrhage and was restored by treatment with ROS scavenger. AQP4-deficient mice had significantly larger PHE lesions and unfavorable survival outcomes compared with wild-type mice. Our data identify AQP4 as a specific BBB-modulating target for alleviating PHE in ICH. Further comprehensive studies are needed to form the preclinical basis for the use of AQP4 enhancers as BBB modulators for preventing delayed cerebral edema after ICH.

Prognostication after intracerebral hemorrhage: a review

Background

Approximately half of patients with spontaneous intracerebral hemorrhage (ICH) die within 1 year. Prognostication in this context is of great importance, to guide goals of care discussions, clinical decision-making, and risk stratification. However, available prognostic scores are hardly used in clinical practice. The purpose of this review article is to identify existing outcome prediction scores for spontaneous intracerebral hemorrhage (ICH) discuss their shortcomings, and to suggest how to create and validate more useful scores.

Main text

Through a literature review this article identifies existing ICH outcome prediction models. Using the Essen-ICH-score as an example, we demonstrate a complete score validation including discrimination, calibration and net benefit calculations. Score performance is illustrated in the Erlangen UKER-ICH-cohort (NCT03183167). We identified 19 prediction scores, half of which used mortality as endpoint, the remainder used disability, typically the dichotomized modified Rankin score assessed at variable time points after the index ICH. Complete score validation by our criteria was only available for the max-ICH score. Our validation of the Essen-ICH-score regarding prediction of unfavorable outcome showed good discrimination (area under the curve 0.87), fair calibration (calibration intercept 1.0, slope 0.84), and an overall net benefit of using the score as a decision tool. We discuss methodological pitfalls of prediction scores, e.g. the withdrawal of care (WOC) bias, physiological predictor variables that are often neglected by authors of clinical scores, and incomplete score validation. Future scores need to integrate new predictor variables, patient-reported outcome measures, and reduce the WOC bias. Validation needs to be standardized and thorough. Lastly, we discuss the integration of current ICH scoring systems in clinical practice with the awareness of their shortcomings.

Conclusion

Presently available prognostic scores for ICH do not fulfill essential quality standards. Novel prognostic scores need to be developed to inform the design of research studies and improve clinical care in patients with ICH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42466-021-00120-5.

Rosuvastatin Nanomicelles Target Neuroinflammation and Improve Neurological Deficit in a Mouse Model of Intracerebral Hemorrhage

Background

Intracerebral hemorrhage (ICH), a devastating subtype of stroke, has a poor prognosis. However, there is no effective therapy currently available due to its complex pathological progression, in which neuroinflammation plays a pivotal role in secondary brain injury. In this work, the use of statin-loaded nanomicelles to target the neuroinflammation and improve the efficacy was studied in a mouse model of ICH.

Methods

Rosuvastatin-loaded nanomicelles were prepared by a co-solvent evaporation method using polyethylene glycol-poly(ε-caprolactone) (PEG-PCL) copolymer as a carrier. The prepared nanomicelles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), and then in vitro and in vivo studies were performed.

Results

TEM shows that the nanomicelles are spherical with a diameter of about 19.41 nm, and DLS shows that the size, zeta potential, and polymer dispersity index of the nanomicelles were 23.37 nm, −19.2 mV, and 0.221, respectively. The drug loading content is 8.28%. The in vivo study showed that the nanomicelles significantly reduced neuron degeneration, inhibited the inflammatory cell infiltration, reduced the brain edema, and improved neurological deficit. Furthermore, it was observed that the nanomicelles promoted the polarization of microglia/macrophages to M2 phenotype, and also the expression of the proinflammatory cytokines, such as IL-1β and TNF-α, was significantly down-regulated, while the expression of the anti-inflammatory cytokine IL-10 was significantly up-regulated. The related mechanism was proposed and discussed.

Conclusion

The nanomicelles treatment suppressed the neuroinflammation that might contribute to the promoted nerve functional recovery of the ICH mouse, making it potential to be applied in clinic.

Decompressive Hemicraniectomy Associated With Ultrasound-Guided Minimally Invasive Puncture and Drainage Has Better Feasibility Than the Traditional Hematoma Evacuation for Deteriorating Spontaneous Intracranial Hemorrhage in the Basal Ganglia Region: A Retrospective Observational Cohort Study

Objectives: Spontaneous intracerebral hemorrhage (ICH) is a devastating disease with higher mortality and disability rates; however, ideal surgical management is still to be determined for critical ICH. The purpose of this study was to prove the feasibility and unique clinical value of a novel combination, decompressive hemicraniectomy associated with ultrasound-guided minimally invasive puncture and drainage (DH + MIPD), for deteriorating ICH in the basal ganglia region. Methods: According to the enrollment criteria, 168 ICH patients were analyzed retrospectively, of which 86 patients received DH + MIPD and 82 patients received DH associated with traditional hematoma evacuation as the control group. The change process of three parameters, including hematoma size, peri-hematoma edema, and intracranial pressure (ICP), in a period of time after operation, as well as the short- and long-term therapeutic effect, was compared. Results: The DH + MIPD method could effectively achieve the evacuation rate of hematoma up to 87% at 5 days post-operation and had the significant advantages of minimal injury to cerebral tissue, less degree of edema, better effect of decreasing ICP, shorter operation time, less blood loss, and lower mortality compared with the control method. The DH + MIPD group had a significantly higher survival rate within 1 year post-operation (P = 0.007) and better functional outcome at 90 and 180 days post-operation (P = 0.004). A subgroup analysis pointed out that the DH + MIPD method had a definite survival advantage for critical ICH patients older than 60 years old and with hematoma located in the left dominant hemisphere. Conclusions: Our results proved the better feasibility of DH + MIPD on hematoma evacuation and implicated its significant advantages of reducing mortality and improving functional recovery. This method provides one more choice for the individualized therapy of ICH in the basal ganglia region.

Early in-hospital exposure to statins and outcome after intracerebral haemorrhage - Results from the Virtual International Stroke Trials Archive

Introduction

Recent data suggest that statin use after intracerebral haemorrhage might be beneficial. However, data on the effects of early in-hospital statin exposure are lacking. Therefore, we sought to assess whether (1) early statin exposure during the acute phase after intracerebral haemorrhage and (2) early continuation of prevalent statin use are associated with favourable functional outcome.

Patients and methods

Data were obtained from the Virtual International Stroke Trials Archive. Patients were categorised according to use patterns of statins during this early in-hospital phase (continuation, discontinuation or new initiation of statins). Univariate and multivariable analyses were conducted to explore the association between early statin exposure and functional outcome.

Results

A total of 919 patients were included in the analysis. Early in-hospital statin exposure (n = 89, 9.7%) was associated with better functional outcome (modified Rankin Scale ≤ 3) compared with 790 patients without statin exposure before or early after the event (66% versus 47%, adjusted OR 2.1, 95% confidence interval 1.3-3.6). Compared with patients without exposure to statins before and early after the event, early continuation of statin therapy (n = 57) was associated with favourable functional outcome (adjusted odds ratio 2.6, 95% confidence interval 1.3-5.2). The association between early continuation of statins and outcome remained robust in sensitivity analyses restricted to patients able to take oral medication within 72 h and one-week survivors.

Discussion

It is possible that part of the observed associations are not due to a protective effect of statins but are confounded by indication bias.

Conclusion

Statin exposure and continuation of prevalent statin therapy early after intracerebral haemorrhage are associated with favourable functional outcome after 90 days.