Perihematomal Edema After Intracerebral Hemorrhage: An Update on Pathogenesis, Risk Factors, and Therapeutic Advances

TREK- 1 Ameliorates Secondary Brain Injury by Regulating Inflammatory Microenvironment via CX3 CL1-CX3 CR1 Pathway After Intracerebral Hemorrhage

Neuroinflammation plays a pivotal role in the pathogenesis of secondary brain injury (SBI) after intracerebral hemorrhage (ICH). TREK-1 is a background potassium channel, and its role in regulating neuroinflammation after ICH remains unclear. In this study, ICH models were induced in wide-type (WT) and TREK knockout mice via intra-striatal administration of collagenase. Additionally, WT ICH mice were treated with the TREK-1 agonist ML67-33. Immunofluorescence, western blot, quantitative real-time PCR, enzyme-linked immunosorbent assay, and RNA-sequencing were performed to determine the role and the mechanism of TREK-1 in regulating neuroinflammation after ICH. The results indicate that TREK-1 deficiency exacerbated microglia/macrophages activation and pro-inflammatory polarization, as well as the influx of inflammatory cytokines and peripheral inflammatory cells compared to WT ICH mice. Conversely, activation of TREK-1 attenuated the inflammatory response and SBI post-ICH. These effects may be mediated through the CX3CL1-CX3CR1 pathway, as validated by specific inhibitors AZD8797. This study identified TREK-1 as a crucial modulator in alleviating SBI by regulating the inflammatory microenvironment via the CX3CL1-CX3CR1 pathway.

Reactive astrocyte-derived exosomes enhance intracranial lymphatic drainage in mice after intracranial hemorrhage

BACKGROUND

After intracranial hemorrhage (ICH), the formation of primary hematoma foci leads to the development of secondary brain injury factors such as perihematomal edema (PHE) and accumulation of toxic metabolites, which severely affect the survival and prognosis of patients. The intracerebral lymphatic system, proposed by Jeffrey J. Iliff et al., plays an important role in central nervous system (CNS) fluid homeostasis and waste removal, while reactive astrocyte-derived exosomes have shown therapeutic potential in CNS disorders. Our study focuses on the effects of hemin-treated reactive astrocyte-derived exosomes on the functional integrity of the glymphatic system (GLS) after ICH and their potential mechanism of action in repairing brain injury.

METHODS

Hemin, an iron-rich porphyrin compound, was used to construct the in vitro model of ICH. Primary astrocytes were treated with complete medium supplemented with different concentrations of hemin to obtain exosomes secreted by them, and mice with ICH induced by the collagenase method were intervened by intranasal administration. Solute clearance efficiency was assessed by intracranial injection of cerebrospinal fluid tracers and fluorescent magnetic beads. Immunofluorescence analysis of Aquaporin 4 (AQP4) polarization and astrocyte proliferation. Magnetic Resonance Imaging was used to visualize and quantify the volume of hematoma foci and PHE, and Western Blot was used to analyze the accumulation of toxic metabolites, while neuronal apoptosis was detected by a combination of TUNEL assay apoptosis detection kit and Nissl staining, and their functional status was analyzed. Gait analysis software was used to detect functional recovery of the affected limb in mice.

RESULTS

Exosomes from hemin treated astrocytes facilitated the recovery of AQP4 polarization and attenuated astrocyte proliferation around hematoma foci in mice with ICH, thereby promoting the recovery of the GLS. Meanwhile, exosomes from hemin treated astrocytes reduced PHE and toxic protein accumulation, decreased apoptosis of cortical neurons on the affected side, and facilitated recovery of motor function of the affected limb, and these effects were blocked by TGN020, an AQP4-specific inhibitor.

CONCLUSIONS

Exosomes from hemin treated astrocytes attenuated secondary brain injury and neurological deficits in mice with ICH by promoting the repair of GLS injury.

Exosomal MicroRNA: an Effective Strategy for the Treatment of Intracerebral Hemorrhage

Intracerebral hemorrhage is a devastating type of stroke, and its pathological mechanism is very complex. Surgical treatment can effectively treat the primary injury caused by mechanical compression of hematoma after intracerebral hemorrhage. However, there is no effective treatment for the secondary injury caused by a series of pathological processes caused by extravasation of blood components, including inflammatory response, oxidative stress, and excitotoxicity. Therefore, there is an urgent need to develop a novel treatment regimen that can reverse the secondary damage of intracerebral hemorrhage. In recent years, as a powerful biomarker, the role of microRNAs (miRNAs) in diseases has been gradually disclosed. As nanocarriers, the miRNAs delivered by exosomes have become a new treatment method and are widely used in the treatment of various diseases. In this paper, the research progress on the mechanism of exosomal miRNAs in intracerebral hemorrhage and its value in prevention, diagnosis, and prognosis is summarized, hoping to provide some reference for the application of exosomal miRNAs in clinical treatment of intracerebral hemorrhage.

T cell receptor activation contributes to brain damage after intracerebral hemorrhage in mice

BACKGROUND

Our previous studies demonstrated that activated T cells accumulate in perihematomal regions following intracerebral hemorrhage (ICH) and exacerbate hemorrhagic brain injury. In the present study, we aimed to explore the mechanisms underlying brain-infiltrating T cell activation and the associated pathophysiological effects in neurological outcomes following ICH.

METHODS

We employed standardized collagenase injection-induced and autologous blood injection models of ICH in male C57BL/6J mice. T cell receptor (TCR) activation, immune cell infiltration, and cytokine production were quantified through immunostaining, flow cytometry, and cytokine arrays at 1- and 3-days post-ICH. Brain edema volume was measured at 3 days post-ICH and neurobehavioral assessments were conducted up to 14 days post-ICH. Pharmacological inhibition of TCR activation was achieved using the TCR-specific inhibitor AX-024, administered intraperitoneally at a dosage of 10 mg/kg 1-hour post-ICH.

RESULTS

Flow cytometry and immunostaining detected TCR activation of brain-infiltrating T cells. Specific TCR activation inhibitor AX-024 administration markedly reduced TCR activation and the production of pro-inflammatory cytokines in the brain at 1- and 3-days post-ICH. Moreover, AX-024 administration led to a significant reduction in the infiltration of other leukocyte populations, and significantly reduced brain edema while improved long-term sensorimotor and cognitive outcomes up to 14 days post-ICH.

DISCUSSION

Our findings underscore the critical role of TCR activation in the mobilization and activation of brain-infiltrating T cells post-ICH. Inhibition of TCR activation via AX-024 administration might be developed as a promising therapeutic strategy to improve neurological outcomes following ICH. However, further research is necessary to thoroughly explore the complex pathophysiological processes involved.

Pathophysiology of Intracerebral Hemorrhage: Recovery Trajectories

Recovery trajectories in intracerebral hemorrhage (ICH) are recognized as distinct from those observed in ischemic stroke. This narrative review aims to clarify the pathophysiology underlying ICH recovery patterns, highlighting the unique timeline and nature of functional improvements seen in ICH survivors. Population-based cohort studies tracking functional outcomes in a longitudinal fashion, along with randomized clinical trial data with standardized outcome assessments, have demonstrated that ICH recovery generally has a delayed onset in the first weeks, followed by a steep early subacute stage recovery (typically up to 3 months) continuing in protracted, gradual improvements beyond 3 to 6 months. Understanding these recovery patterns, and how these differ from ischemic stroke, is crucial for providing accurate prognostic information, facilitating targeted health care delivery, and optimizing therapeutic interventions and the design of ICH randomized trials. This article synthesizes current evidence on early- and late-stage functional recovery trajectories in primary, spontaneous ICH and cognitive outcomes, emphasizing the clinical and research implications of these recovery patterns.

miR-874-3p Alleviates Macrophage-Mediated Inflammatory Injury in Intracerebral Hemorrhage by Targeting HIPK2

Macrophages mediate secondary inflammatory injury after intracerebral hemorrhage (ICH). This study aimed to investigate the role and molecular mechanisms of miR-874-3p in macrophage polarization. A mice model of ICH was constructed by autologous blood injection. Macrophages were treated with erythrocyte lysates to construct an ICH cell model. Real-time quantitative reverse transcription PCR (RT-qPCR) was used to detect miR-874-3p levels. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect macrophage polarization markers. Brain tissue water content and neurological deficit scores were used to assess the degree of inflammatory injury in ICH mice. RNA immunoprecipitation (RIP) and Dual-luciferase reporter (DLR) assays were used to analyze the targeting relationship between miR-874-3p and target mRNA. miR-874-3p levels were decreased in ICH mice and erythrocyte lysates-treated macrophages. miR-874-3p mimic alleviated inflammatory injury, decreased the levels of M1 macrophage markers, and increased the levels of M2 macrophage markers, suggesting that miR-874-3p is involved in ICH by regulating macrophage polarization. HIPK2 is the target mRNA of miR-874-3p and has the opposite expression pattern of miR-874-3p. Overexpression of HIPK2 attenuates the effect of elevated miR-874-3p levels on macrophage polarization and inflammatory brain injury in ICH mice. miR-874-3p regulates macrophage polarization in ICH by targeting HIPK2. Therefore, the miR-874-3p/HIPK2 axis may be a promising target for ICH treatment.

Retrospective Analysis of the Impact of a Collaborative Multidisciplinary Care Model on the Efficiency of Emergency Care and Neurological Function and Prognosis of Comatose Patients With Emergency Cerebral Hemorrhage

Background and Aims

Cerebral hemorrhage is often accompanied by severe neurological function damage. The collaborative multidisciplinary care means multidisciplinary medical personnel work together. This study investigated the effects of a collaborative multidisciplinary care model on the prognosis of comatose patients with cerebral hemorrhage in emergency medicine.

Methods

The control group was given routine care, and the study group was given a collaborative multidisciplinary care model intervention. Record the success rate of first aid and the changes in neurological function. Patients were followed up for 6 months, and mortality and disability rates were recorded. SPSS 23.0 software was used to analyze the data, and the count data were expressed as [cases (%)] by χ2 test, and the measurement data were expressed as (x ± s) by t-test.

Results

The success rate of first aid in the control group and the study group was 91.13% and 94.34%, respectively, which was significantly lower than that of the control group (p < 0.05); the time for intravenous medication and the total time for first aid in the study group were significantly lower than that of the control group (p < 0.001). After the intervention, MMSE scores, FMA scores, and Barthel indexes were significantly higher with lower NIHSS scores in the study group than in the control group (p < 0.05). Compared with the pre-intervention period, all scores of motor, speech, and eye-opening were significantly higher in both groups, and the study group was significantly higher than the control group after the intervention (p < 0.05). The complication rate and disability rate of the study group were lower than that of the control group (p < 0.05).

Conclusion

A collaborative multidisciplinary care model for comatose patients with cerebral hemorrhage may improve the efficiency of emergency care, improve the patient's neurological function, reduce the disability rate of the patients, and improve the prognosis of the patients.

Microglial Mechanisms and Therapeutic Potential in Brain Injury Post-Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a particularly common public health problem with a high mortality and disability rate and no effective treatments to enhance clinical prognosis. The increased aging population, improved vascular prevention, and augmented use of antithrombotic agents have collectively contributed to the rise in ICH incidence over the past few decades. The exploration and understanding of mechanisms and intervention strategies has great practical significance for expanding treatments and improving prognosis of ICH. Microglia, as resident macrophages of central nervous system, are responsible for the first immune defense post-ICH. After ICH, M1 microglia is firstly activated by primary injury and thrombin; subsequently, reactive microglia can further amplify the immune response and exert secondary injury (eg, oxidative stress, neuronal damage, and brain edema). The pro-inflammatory phenotype transmits to M2 microglia within 7 days post-ICH, which plays a key role in erythrophagocytosis and limiting the inflammatory secondary injury. Microglial M2 polarization has significant implications for improving prognosis, this process can be mediated through crosstalk with other cells, metabolic changes, and microbiota interaction. Clarifying the effect, timing, and potential downstream effects of multiple mechanisms that synergistically trigger anti-inflammatory responses may be necessary for clinical translation. Analyses of such intricate interaction between microglia cells and brain injury/repair mechanisms will contribute to our understanding of the critical microglial responses to microenvironment and facilitating the discovery of appropriate intervention strategies. Here, we present a comprehensive overview of the latest evidences on microglial dynamics following ICH, their role in driving primary/secondary injury mechanisms as well as neurorepair/plasticity, and possible treatment strategies targeting microglia.

Prognostic value of glycolipid metabolism index on complications and mechanical ventilation in intensive care unit patients with intracerebral hemorrhage: a retrospective cohort study using the MIMIC-IV database

Objective

This study aimed to evaluate the predictive capability of glycolipid metabolism index (triglyceride-glucose index, TyG; atherogenic index of plasma, AIP; triglyceride to high-density lipoprotein cholesterol ratio, TG/HDL-C; and non-HDL-C to HDL-C ratio, NHHR) for complications and ventilator use in patients with intracerebral hemorrhage (ICH) admitted to the intensive care unit (ICU).

Methods

Patients with ICH requiring ICU admission were selected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Outcomes assessed included incidence of complications and use of ventilator support. Multivariate logistic regression, receiver operating characteristic (ROC) analysis, and restricted cubic spline were employed to investigate the relationship between glycolipid metabolism index and clinical outcomes in ICH patients.

Results

A total of 733 patients were included. Multivariate logistic regression analysis revealed that elevated TyG, AIP, and TG/HDL-C levels were associated with increased incidence of complications and prolonged ventilator use. ROC curve analysis demonstrated that TyG (AUC 0.646) exhibited the strongest predictive ability for multiple complications in ICH patients. Further multiple regression analysis identified TG/HDL-C as an independent predictor of deep vein thrombosis, while TyG, AIP, and TG/HDL-C independently predicted pulmonary embolism, and TyG, AIP, NHHR, and TG/HDL-C independently predicted acute kidney injury. Moreover, ventilator use further heightened the risk of multiple complications in ICU patients with elevated glycolipid metabolism index.

Conclusion

Glycolipid metabolism index represent promising and readily accessible biomarkers for predicting multiple complications and ventilator use in ICU patients with ICH.

Apolipoprotein E-ε4 allele is associated with perihematomal brain edema and poor outcomes in patients with intracerebral hemorrhage

Intracerebral hemorrhage (ICH) poses significant disability and mortality risks and perihematomal edema (PHE) plays a crucial role in ICH prognosis. The ApoE-ε4 allele has been implicated in exacerbating PHE and influencing neurological recovery post-ICH, yet, this specific association has not been explored much. This study aimed to investigate the correlation between ApoE-ε4 allele, PHE, and clinical prognosis in patients with ICH. We conducted a prospective observational cohort study at the Affiliated Hospital of Guizhou Medical University from January 2020 to December 2023. We enrolled patients with supratentorial ICH patients and analyzed ApoE gene alleles, clinical baseline data, blood biochemical indices, and imaging findings. We considered ApoE-ε4 carrier status as an exposure variable and compared PHE volumes between ApoE-ε3 (ε3/ε3) and ApoE-ε4 (ε2/ε4, ε3/ε4, ε4/ε4) carriers. We also compared clinical and imaging characteristics between the good prognosis group (modified Rankin score 0-3) and the poor prognosis group (modified Rankin score 4-6). Finally, we examined the association between ApoEε4 and PHE volume and poor prognosis at discharge. Among 153 patients, 63 (41%) carried ApoE-ε4. ApoE-ε4 carriers had significantly higher PHE volumes at 24 h and on days 5-7 compared to ApoE-ε3 carriers. The poor prognosis group had a higher proportion of ApoE-ε4 carriers (53.9% vs. 28.6%, p = 0.001) and increased PHE volumes. ApoE-ε4 (OR 2.438, p = 0.02) and PHE (OR 1.048, p = 0.015) were independent predictors of poor prognosis. The area under the curve for ApoE-ε4 was 0.627, and for PHE volume, it was 0.698. The ICH patients carrying the ApoE-ε4 allele show severe PHE and poorer outcomes. Carrying ApoE-ε4 gene is an independent predictor for poor outcomes in patients with ICH.Trial registration: ClinicalTrials.gov, NCT05687201. Registered June 1, 2023, Effect of Apolipoprotein E on the Prognosis of Patients with Intracerebral Hemorrhage-Full Text View-ClinicalTrials.gov "prospective registered".

PF4 inhibits ferroptosis-mediated intracerebral hemorrhage through modulating the CXCR3/AKT1/SLC7A11 signaling pathway

Ferroptosis plays a crucial role in the secondary pathophysiological damage to brain tissue surrounding hematomas after intracerebral hemorrhage (ICH). While platelet factor 4 (PF4) is known to promote regeneration following peripheral nerve injury, its role in brain tissue repair after cerebral hemorrhage remains unclear. In this study, Hemin-induced PC12 cells were treated with various inhibitors and assessed for viability, oxidative stress, and ferroptosis using a combination of assays, including CCK-8 (Cell Counting Kit-8), EdU (5-Ethynyl-2'-deoxyuridine), flow cytometry, and immunofluorescence. ICH cells were also treated with recombinant PF4 (Rm-PF4) and a CXCR3 antagonist (AMG487) to investigate the mechanism by which Rm-PF4 influences Hemin-induced PC12 cell injury and inflammation. Subsequently, ICH mouse models were established via collagenase injection. Neurological function in these mice was evaluated using the Cylinder and Corner tests. Histopathological damage to brain tissue was analyzed through HE, TUNEL, and Nissl staining, as well as immunohistochemistry, to further explore the role of Rm-PF4 in controlling neuroinflammation in vivo. Results showed that Rm-PF4 inhibited Hemin-mediated ferroptosis-induced PC12 cell damage and inflammation by activating the CXCR3/AKT1/SLC7A11 signaling pathway. Blocking the CXCR3/AKT1/SLC7A11 pathway partially reversed PF4's protective effects on Hemin-induced PC12 cells.In ICH mice, pro-inflammatory marker CD16 (3rd day) and anti-inflammatory marker Arg1 (7th day) were significantly decreased and increased, respectively (p<0.05). IL-6, TNF-α, and IL-1β levels were down-regulated in brain tissues after Rm-PF4 injection, which was significantly reversed by AMG487. PF4 inhibits ferroptosis after ICH reduced PC12 cell damage and the inflammatory response via activating the CXCR3/AKT1/SLC7A11 pathway.

Analysis of Risk Factors for Hemorrhagic Transformation of Cerebral Infarction and Recurrence of Cerebral Infarction: A Retrospective Study on Cerebral Infarction Patients with or without Hemorrhagic Transformation

Background

Acute ischemic stroke, especially hemorrhage cerebral infarction (HCI), resulted in the leading causes of mortality and long-term disability across populations. However, fewer researches have focused on the risk factors of first admission and recurrence of HCI.

Methods

The study included 1857 patients who underwent cerebral infarction with or without hemorrhagic transformation. Clinical characteristics were collected, and univariate and multivariate analysis were performed to explore the risk factors. The subgroup analysis of cerebral infarction recurrence was performed. ROC analysis was utilized, and AUCs were showed the diagnostic values of the risk factors.

Results

Compared to the patients with non-hemorrhage cerebral infarction, the patients with hemorrhage cerebral infarction were older and had higher Neutrophil infiltration, AST expression, globulin and BUN, while had lower ALT expression, triglyceride, PT, APTT, homocysteine, d-dimer, CRP and glycosylated hemoglobin. Utilizing univariate and multivariate analysis, age, thrombolytic, Hb, AST and glycosylated hemoglobin were the risk factors between the patients with hemorrhagic cerebral infarction and non-hemorrhagic cerebral infarction. ROC analysis was performed to demonstrate that glycosylated hemoglobin was a diagnostic biomarker for the patients with hemorrhagic cerebral infarction and non-hemorrhagic cerebral infarction (AUC = 0.808). Utilizing univariate and multivariate analysis, age, hypertension history, LDL and MRS Score on admission were the risk factors between non-hemorrhagic cerebral infarction patients with first admission or the cerebral infarction recurrence. ROC analysis was performed to demonstrate MRS Score on admission was a diagnostic biomarker for recurrence of cerebral infarction in patients with non-hemorrhagic cerebral infarction (AUC = 0.708). Utilizing univariate and multivariate analysis, only hypertension history was the risk factors between hemorrhagic cerebral infarction patients with first admission or the cerebral infarction recurrence.

Conclusion

In conclusion, age, hypertension history, LDL and MRS Score on admission were the risk factors between cerebral infarction patients with first admission or the cerebral infarction recurrence.

Human platelet lysate: a potential therapeutic for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a major public health challenge worldwide, and is associated with elevated rates of mortality, disability, and morbidity, especially in low- and middle-income nations. However, our knowledge of the detailed molecular processes involved in ICH remains insufficient, particularly those involved in the secondary injury stage, resulting in a lack of effective treatments for ICH. Human platelet lysates (HPL) are abundant in bioactive factors, and numerous studies have demonstrated their beneficial effects on neurological diseases, including their anti-neuroinflammatory ability, anti-oxidant effects, maintenance of blood-brain barrier integrity, and promotion of neurogenesis. In this review, we thoroughly explore the potential of HPL for treating ICH from three critical perspectives: the rationale for selecting HPL as a treatment for ICH, the mechanisms through which HPL contributes to ICH management, and the additional measures necessary for HPL as a treatment for ICH. We elucidate the role of platelets in ICH pathophysiology and highlight the limitations of the current treatment options and advancements in preclinical research on the application of HPL in neurological disorders. Furthermore, historical developments and preparation methods of HPL in the field of biomedicine are discussed. Additionally, we summarize the bioactive molecules present in HPL and their potential therapeutic effects in ICH. Finally, we outline the issues that must be addressed regarding utilizing HPL as a treatment modality for ICH.

PDGFRα inhibition reduces myofibroblast expansion in the fibrotic rim and enhances recovery after ischemic stroke

Ischemic stroke is a major cause of disability in adults. Early treatment with thrombolytics and/or thrombectomy can significantly improve outcomes; however, following these acute interventions, treatment is limited to rehabilitation therapies. Thus, identification of therapeutic strategies that can help restore brain function in the post-acute phase remains a major challenge. Here we report that genetic or pharmacologic inhibition of the PDGF-CC/PDGFRα pathway, which has previously been implicated in stroke pathology, significantly reduced myofibroblast expansion in the border of the fibrotic scar and improved outcome in a sensory-motor integration test after experimental ischemic stroke. This was supported by gene expression analyses of cerebrovascular fragments showing upregulation of profibrotic/proinflammatory genes, including genes of the TGF pathway, after ischemic stroke or intracerebroventricular injection of active PDGF-CC. Further, longitudinal intravital 2-photon imaging revealed that inhibition of PDGFRα dampened the biphasic pattern of stroke-induced vascular leakage and enhanced vascular perfusion in the ischemic lesion. Importantly, we found PDGFRα inhibition to be effective in enhancing functional recovery when initiated 24 hours after ischemic stroke. Our data implicate the PDGF-CC/PDGFRα pathway as a crucial mediator modulating post-stroke pathology and suggest a post-acute treatment opportunity for patients with ischemic stroke targeting myofibroblast expansion to foster long-term CNS repair.

Isoform-selective and non-selective rho-kinase inhibitors do not affect collagenase-induced intracerebral hemorrhage outcomes in mice: Influence of sex and circadian cycle

Rho-associated protein kinase (ROCK) inhibitors are therapeutic candidates in ischemic stroke and subarachnoid hemorrhage. However, their efficacy in intracerebral hemorrhage (ICH) is unknown. Here, we tested the efficacy of fasudil (10 mg/kg), an isoform-nonselective ROCK inhibitor, and NRL-1049 (10 mg/kg), a novel inhibitor with 43-fold higher selectivity for ROCK2 isoform compared with ROCK1, in a collagenase-induced ICH model in mice. Both short (1-3 days) and prolonged (14 days) therapeutic paradigms were tested using robust sample sizes in both males and females and in active and inactive circadian stages. Outcome readouts included weight loss, mortality, hematoma volume, hemispheric swelling, brain water content, BBB permeability to large molecules, and sensorimotor and cognitive function. We found the treatments safe but not efficacious in improving the hematoma volume, BBB disruption, or neurological deficits in this collagenase-induced ICH model. Intriguingly, however, induction of ICH during the active circadian stage was associated with worse tissue and behavioral outcomes compared with the inactive stage.

Predictive Value of Machine Learning Models for Cerebral Edema Risk in Stroke Patients: A Meta-Analysis

INTRODUCTION

Stroke patients are at high risk of developing cerebral edema, which can have severe consequences. However, there are currently few effective tools for early identification or prediction of this risk. As machine learning (ML) is increasingly used in clinical practice, its effectiveness in predicting cerebral edema risk in stroke patients has been explored. Nonetheless, the lack of systematic evidence on its predictive value challenges the update of simple and user-friendly risk assessment tools. Therefore, we conducted a systematic review to evaluate the predictive utility of ML for cerebral edema in stroke patients.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Database up to February 21, 2024. The risk of bias in selected studies was assessed using a bias assessment tool for predictive models. Meta-analysis synthesized results from validation sets.

RESULTS

We included 22 studies with 25,096 stroke patients and 25 models, which were constructed using common and interpretable clinical features. In the validation cohort, the models achieved a concordance index (c-index) of 0.840 (95% CI: 0.810-0.871) for predicting poststroke cerebral edema, with a sensitivity of 0.76 (95% CI: 0.72-0.79) and a specificity of 0.87 (95% CI: 0.83-0.90).

CONCLUSION

ML models are significant in predicting poststroke cerebral edema, providing clinicians with a powerful prognostic tool. However, radiomics-based research was not included. We anticipate advancements in radiomics research to enhance the predictive power of ML for poststroke cerebral edema.

Neutrophil Extracellular Traps Induce Brain Edema Around Intracerebral Hematoma via ERK-Mediated Regulation of MMP9 and AQP4

Perihematomal edema (PHE) significantly aggravates secondary brain injury in patients with intracerebral hemorrhage (ICH), yet its detailed mechanisms remain elusive. Neutrophil extracellular traps (NETs) are known to exacerbate neurological deficits and worsen outcomes after stroke. This study explores the potential role of NETs in the pathogenesis of brain edema following ICH. The rat ICH model was created, immunofluorescence and Western blot were used to examine neutrophil accumulation, NET markers citrullinated histone H3 (CitH3) and myeloperoxidase (MPO), tight junction proteins (ZO-1 and Occludin), Aquaporin-4 (AQP4), matrix metalloproteinase-9 (MMP-9), and ERK phosphorylation (p-ERK) in brain tissues surrounding the hematoma. TUNEL staining and behavioral tests were employed to evaluate neuronal apoptosis and neurological dysfunction, while blood-brain barrier (BBB) permeability and brain edema were also measured by Evans blue and brain water content. Furthermore, the molecular mechanisms related to NETs-induced PHE were investigated using NETs, ERK, MMP-9 and AQP4 regulators, respectively. Ly6G+ neutrophils surrounding the hematoma developed NETs within 3 days post-ICH. NETs decreased tight junction proteins, destroyed BBB integrity, promoted brain edema, increased neuronal apoptosis, and exacerbated neurological deficits. Conversely, inhibition of NETs mitigated PHE, reduced neuronal apoptosis, and improved neurological functions. Mechanistically, NET-induced PHE was originated from impairment of BBB tight junction via ERK/MMP9 pathway, coupled with ERK-mediated AQP4 downregulation in perihematomal regions. These findings elucidated the effects of NETs on PHE, which offered promising insights for targeting NETs to relieve brain edema and secondary brain injury post-ICH.

Advances in genetically modified neural stem cell therapy for central nervous system injury and neurological diseases

Neural stem cells (NSCs) have increasingly been recognized as the most promising candidates for cell-based therapies for the central nervous system (CNS) injuries, primarily due to their pluripotent differentiation capabilities, as well as their remarkable secretory and homing properties. In recent years, extensive research efforts have been initiated to explore the therapeutic potential of NSC transplantation for CNS injuries, yielding significant advancements. Nevertheless, owing to the formation of adverse microenvironment at post-injury leading to suboptimal survival, differentiation, and integration within the host neural network of transplanted NSCs, NSC-based transplantation therapies often fall short of achieving optimal therapeutic outcomes. To address this challenge, genetic modification has been developed an attractive strategy to improve the outcomes of NSC therapies. This is mainly attributed to its potential to not only enhance the differentiation capacity of NSCs but also to boost a range of biological activities, such as the secretion of bioactive factors, anti-inflammatory effects, anti-apoptotic properties, immunomodulation, antioxidative functions, and angiogenesis. Furthermore, genetic modification empowers NSCs to play a more robust neuroprotective role in the context of nerve injury. In this review, we will provide an overview of recent advances in the roles and mechanisms of NSCs genetically modified with various therapeutic genes in the treatment of neural injuries and neural disorders. Also, an update on current technical parameters suitable for NSC transplantation and functional recovery in clinical studies are summarized.

Annao Pingchong decoction attenuates oxidative stress and neuronal apoptosis following intracerebral hemorrhage via RAGE-NOX2/4 axis

Background

Intracerebral hemorrhage (ICH) is a severe condition associated with high mortality and disability rates. Oxidative stress plays a critical role in the development of secondary brain injury (SBI) following ICH. Previous research has demonstrated that Annao Pingchong decoction (ANPCD) treatment for ICH has antioxidant effects, but the exact mechanism is not yet fully understood.

Objective

This study aimed to investigate the neuroprotective effects of ANPCD on oxidative stress and neuronal apoptosis after ICH by targeting the receptor for advanced glycation end products (RAGE)-NADPH oxidase (NOX) 2/4 signaling axis.

Methods

The research involved the creation of rat ICH models, the mNSS assay to assess neurological function, Nissl staining to evaluate neuronal damage, and biochemical assays to measure oxidative and antioxidant levels. The expression of RAGE-NOX2/4 axis proteins was analyzed using western blotting and immunofluorescence, while neuronal apoptosis was assessed with TUNEL staining. Furthermore, after performing quality control of drug-containing serum using UPLC-MS/MS, we employed an in vitro model of heme-induced injury in rat cortical neurons to investigate the neuroprotective mechanisms of ANPCD utilizing RAGE inhibitors.

Results

The findings indicated that ANPCD improved neurological deficits, reduced neuronal damage, decreased ROS and MDA levels, and increased the activities enzymatic activities of SOD, CAT, GSH and GPX. Additionally, it suppressed the RAGE-NOX2/4 signaling axis and neuronal apoptosis.

Conclusion

ANPCD exhibits neuroprotective effects by inhibiting the RAGE-NOX2/4 signaling axis, thereby alleviating neuronal oxidative stress and apoptosis following ICH.

Cystatin C Attenuates Perihematomal Secondary Brain Injury by Inhibiting the Cathepsin B/NLRP3 Signaling Pathway in a Rat Model of Intracerebral Hemorrhage

Secondary brain injury (SBI) is a noticeable contributor to the high mortality and morbidity rates associated with intracerebral hemorrhage (ICH), and effective treatment options remain limited. Cystatin C (CysC) emerges as a novel candidate for SBI intervention. The therapeutic effects and underlying mechanisms of CysC in mitigating SBI following ICH were explored in the current research. An in vivo ICH rat model was established by injecting autologous blood into the right caudate nucleus. Western blotting (WB) was utilized to assess the levels of CysC, cathepsin B (CTSB), and the NLRP3 inflammasome. Subsequently, the ICH rat model was treated with exogenous CysC supplementation or CysC knockdown plasmids. Various parameters, including Evans blue (EB) extravasation, brain water content, and neurological function in rats, were examined. RT-qPCR and WB were employed to determine the expression levels of CTSB and the NLRP3 inflammasome. The co-expression of CTSB, CysC, and NLRP3 inflammasome with GFAP, NeuN, and Iba1 was assessed through double-labeled immunofluorescence. The interaction between CysC and CTSB was investigated using double-labeled immunofluorescence and co-immunoprecipitation. The findings revealed an elevation of CysC expression level, particularly at 24 h after ICH. Exogenous CysC supplementation alleviated severe brain edema, neurological deficit scores, and EB extravasation induced by ICH. Conversely, CysC knockdown produced opposite effects. The expression levels of CTSB and the NLRP3 inflammasome were significantly risen following ICH, and exogenous CysC supplement attenuated their expression levels. Double-labeled immunofluorescence illustrated that CysC, CTSB, and the NLRP3 inflammasome were predominantly expressed in microglial cells, and the interaction between CysC and CTSB was evidenced. CysC exhibited potential in ameliorating SBI following ICH via effectively suppressing the activation of the NLRP3 inflammasome mediated by CTSB specifically in microglial cells. These findings underscore the prospective therapeutic efficacy of CysC in the treatment of ICH-induced complications.

No Benefit of 3% Hypertonic Saline Following Experimental Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a stroke subtype with a high mortality rate (~ 40%). After ICH, the mass effect of the hematoma and edema contribute to raised intracranial pressure (ICP) and poor outcome. Endogenous compensatory mechanisms that blunt ICP elevations include redirection of venous blood and cerebrospinal fluid, along with brain tissue compliance (e.g., decreased cell volume, increased cell density); however, these limited reserves can be exhausted after severe stroke, resulting in decompensated ICP that requires careful clinical management. Management strategies can include administration of hypertonic saline (HTS), an osmotic agent that putatively attenuates edema, and thereby ICP elevations. Evidence regarding the efficacy of HTS treatment following ICH remains limited. In this study, adult male rats were given a collagenase-induced striatal ICH and a bolus of either 3% HTS or 0.9% saline vehicle at 2- and 14-hours post-stroke onset. Neurological deficits, edema, ipsilateral cell volume and density (in areas S1 and CA1), and contralateral CA1 ultrastructural morphology were assessed 24 h post-ICH. Animals had large bleeds (median 108.2 µL), extensive edema (median 83.9% brain water content in ipsilateral striatum), and evident behavioural deficits (median 5.4 neurological deficit scale score). However, HTS did not affect edema (p ≥ 0.4797), behaviour (p = 0.6479), cell volume (p ≥ 0.1079), or cell density (p ≥ 0.0983). Qualitative ultrastructural assessment of contralateral area CA1 suggested that HTS administration was associated with paradoxical cellular swelling in ICH animals. Overall, there was no benefit with administering 3% HTS after ICH.

"Baihui" (DU20)-penetrating "Qubin" (GB7) acupuncture on blood-brain barrier integrity in rat intracerebral hemorrhage models via the RhoA/ROCK II/MLC 2 signaling pathway

BACKGROUND

Blocking the RhoA/ROCK II/MLC 2 (Ras homolog gene family member A/Rho kinase II/myosin light chain 2) signaling pathway can initiate neuroprotective mechanisms against neurological diseases such as stroke, cerebral ischemia, and subarachnoid hemorrhage. Nevertheless, it is not clear whether and how disrupting the RhoA/ROCK II/MLC 2 signaling pathway changes the pathogenic processes of the blood-brain barrier (BBB) after intracerebral hemorrhage (ICH). The present investigation included the injection of rat caudal vein blood into the basal ganglia area to replicate the pathophysiological conditions caused by ICH.

METHODS

Scalp acupuncture (SA) therapy was performed on rats with ICH at the acupuncture point "Baihui"-penetrating "Qubin," and the ROCK selective inhibitor fasudil was used as a positive control to evaluate the inhibitory effect of acupuncture on the RhoA/ROCK II/MLC 2 signaling pathway. Post-assessments included neurological deficits, brain edema, Evans blue extravasation, Western blot, quantitative polymerase chain reaction, and transmission electron microscope imaging.

RESULTS

We found that ROCK II acts as a promoter of the RhoA/ROCK II/MLC 2 signaling pathway, and its expression increased at 6 h after ICH, peaked at 3 days, and then decreased at 7 days after ICH, but was still higher than the pre-intervention level. According to some experimental results, although 3 days is the peak, 7 days is the best time point for acupuncture treatment. Starting from 6 h after ICH, the neurovascular structure and endothelial cell morphology around the hematoma began to change. Based on the changes in the promoter ROCK II, a 7-day time point was selected as the breakthrough point for treating ICH model rats in the main experiment. The results of this experiment showed that both SA at "Baihui"-penetrating "Qubin" and treatment with fasudil could improve the expression of endothelial-related proteins by inhibiting the RhoA/ROCK II/MLC 2 signaling pathway and reduce neurological dysfunction, brain edema, and BBB permeability in rats.

CONCLUSION

This study found that these experimental data indicated that SA at "Baihui"-penetrating "Qubin" could preserve BBB integrity and neurological function recovery after ICH by inhibiting RhoA/ROCK II/MLC 2 signaling pathway activation and by regulating endothelial cell-related proteins.

Protective effects of flavonoids against intracerebral and subarachnoid hemorrhage (Review)

Intracerebral hemorrhage (ICH), known as non-traumatic cerebrovascular rupture and hemorrhage, often occurs in the deep basal brain segment. It is known for its high morbidity and mortality rates. Subarachnoid hemorrhage (SAH) is a clinical syndrome caused by the rupture of blood vessels at the base or surface of the brain that allows blood to flow directly into the subarachnoid space. It progresses quickly and typically manifests at younger ages compared with ICH. ICH and SAH are both devastating events in the category of hemorrhagic strokes and are attracting increasing attention from researchers. Flavonoids, being important natural molecules, have remarkable anti-inflammatory and antioxidant effects. Flavonoids have extensive biological activities in inflammation and oxidative stress (OS), and have protective effects in vascular function associated with cerebrovascular diseases. They have an impact on the onset of ICH and SAH by targeting various pathways, including the suppression of inflammation and OS. Recently, the role of flavonoid compounds in ICH and SAH has also received increasing interest. Thus, to serve as a resource for the prevention and treatment of ICH and SAH, the present review provided an overview of the research on flavonoid compounds in the prevention of brain damage after these two conditions have occurred.

Based on hematoma and perihematomal tissue NCCT imaging radiomics predicts early clinical outcome of conservatively treated spontaneous cerebral hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is a very serious kind of stroke. If the outcome of patients can be accurately assessed at the early stage of disease occurrence, it will be of great significance to the patients and clinical treatment. The present study was conducted to investigate whether non-contrast computer tomography (NCCT) models of hematoma and perihematomal tissues could improve the accuracy of short-term prognosis prediction in ICH patients with conservative treatment. In this retrospective analysis, a total of 166 ICH patients with conservative treatment during hospitalization were included. Patients were randomized into a training group (N = 132) and a validation group (N = 34) in a ratio of 8:2, and the functional outcome at 90 days after clinical treatment was assessed by the modified Rankin Scale (mRS). Radiomic features of hematoma and perihematomal tissues of 5 mm, 10 mm, 15 mm were extracted from NCCT images. Clinical factors were analyzed by univariate and multivariate logistic regression to identify independent predictive factors. In the validation group, the mean area under the ROC curve (AUC) of the hematoma was 0.830, the AUC of the perihematomal tissue within 5 mm, 10 mm, 15 mm was 0.792, 0.826, 0.774, respectively, and the AUC of the combined model of hematoma and perihematomal tissue within 10 mm was 0.795. The clinical-radiomics nomogram consisting of five independent predictors and radiomics score (Rad-score) of the hematoma model were used to assess 90-day functional outcome in ICH patients with conservative treatment. Our findings found that the hematoma model had better discriminative efficacy in evaluating the early prognosis of conservatively managed ICH patients. The visual clinical-radiomics nomogram provided a more intuitive individualized risk assessment for 90-day functional outcome in ICH patients with conservative treatment. The hematoma could remain the primary therapeutic target for conservatively managed ICH patients, emphasizing the need for future clinical focus on the biological significance of the hematoma itself.

Atorvastatin-induced intracerebral hemorrhage is inhibited by berberine in zebrafish

Intracerebral hemorrhage (ICH), for which there are currently no effective preventive or treatment methods, has a very high fatality rate. Statins, such as atorvastatin (ATV), are the first-line drugs for regulating blood lipids and treating hyperlipidemia-related cardiovascular diseases. However, ATV-associated ICH has been reported, although its incidence is rare. In this study, we aimed to investigate the protective action and mechanisms of berberine (BBR) against ATV-induced brain hemorrhage. We established an ICH model in zebrafish induced by ATV (2 μM) and demonstrated the effects of BBR (10, 50, and 100 μM) on ICH via protecting the vascular network using hemocyte staining and three transgenic zebrafish. BBR was found to reduce brain inflammation and locomotion injury in ICH-zebrafish. Mechanism research showed that ATV increased the levels of VE-cadherin and occludin proteins but disturbed their localization at the cell membrane by abnormal phosphorylation, which decreased the number of intercellular junctions between vascular endothelial cells (VECs), disrupting the integrity of vascular walls. BBR reversed the effects of ATV by promoting autophagic degradation of phosphorylated VE-cadherin and occludin in ATV-induced VECs examined by co-immunoprecipitation (co-IP). These findings provide crucial insights into understanding the BBR mechanisms involved in the maintenance of vascular integrity and in mitigating adverse reactions to ATV.

Diselenide-Bridged Mesoporous Silica-Based Nanoplatform with a Triple ROS-Scavenging Effect for Intracerebral Hemorrhage Treatment

Oxidative stress (OS) is a major mediator of secondary brain injury following intracerebral hemorrhage (ICH). Thus, antioxidant therapy is emerging as an attractive strategy to combat ICH. To achieve both reactive oxygen species (ROS) scavenging ability and on-demand drug release ability, we constructed a novel polydopamine (PDA)-coated diselenide-bridged mesoporous silica nanoparticle (DSeMSN) drug delivery system (PDA-DSeMSN). Edaravone (Eda) was blocked in the pores of DSeMSN by covering the pores with PDA as a gatekeeper. The drug maintained nearly "zero release" before reaching the lesion site, while in the ROS-enriched circumstances, the PDA shell went through degradation and the doped diselenide bonds broke up, triggering the disintegration of nanoparticles and leading to Eda release. Interestingly, the ROS-degradable property of the PDA shell and diselenide bond endowed the system with enhanced ROS-eliminating capacity. The synergistic effect of ROS-responsive drug delivery and ROS-scavenging PDA-DSeMSN showed efficient antioxidative and mitochondria protective performance without apparent toxicity in vitro. Importantly, PDA-DSeMSN@Eda through intravenous administration specifically accumulated in perihematomal sites and demonstrated robust neuroprotection in an ICH mouse model through antioxidative and antiapoptotic effects with high biological safety. Thus, the PDA-DSeMSN platform holds tremendous potential as an excellent carrier for on-demand delivery of drugs and provides a new and effective strategy for the clinical treatment of ICH.

Developing an in vitro model of haematoma for study of intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a devastating neurovascular attack with limited treatment options. Alternative, pre-clinical modelling approaches are required to identify and trial therapeutic drug compounds. In this study we have used alginate hydrogels to model blood insult in vitro. Human whole blood was mixed with alginate and encapsulated into hydrogel beads. Beads were then incorporated in a second layer of alginate containing hyaluronic acid/chitosan nanoparticles to mimic the mechanical properties of brain tissue and create a model haematoma. Beads and model haematomas were characterised to profile size, volume, mechanical properties, release capacity and storage stability over time. Beads and model haematomas stimulate a pro-inflammatory phenotype in human monocytic and macrophage-like cells, however have no pathogenic effect on brain endothelial and neuronal cell survival or function. In conclusion, we have developed an effective strategy to model ICH in vitro, to investigate the human immune response to blood insult.

Neuro-imaging in intracerebral hemorrhage: updates and knowledge gaps

Intracerebral hemorrhage (ICH) is characterized by hematoma development within the brain's parenchyma, contributing significantly to the burden of stroke. While non-contrast head computed tomography (CT) remains the gold standard for initial diagnosis, this review underscores the pivotal role of magnetic resonance imaging (MRI) in ICH management. Beyond diagnosis, MRI offers invaluable insights into ICH etiology, prognosis, and treatment. Utilizing echo-planar gradient-echo or susceptibility-weighted sequences, MRI demonstrates exceptional sensitivity and specificity in identifying ICH, aiding in differentiation of primary and secondary causes. Moreover, MRI facilitates assessment of hemorrhage age, recognition of secondary lesions, and evaluation of perihematomal edema progression, thus guiding tailored therapeutic strategies. This comprehensive review discusses the multifaceted utility of MRI in ICH management, highlighting its indispensable role in enhancing diagnostic accuracy as well as aiding in prognostication. As MRI continues to evolve as a cornerstone of ICH assessment, future research should explore its nuanced applications in personalized care paradigms.

Dynamic Imaging of Blood Coagulation Within the Hematoma of Patients With Acute Hemorrhagic Stroke

BACKGROUND

The dynamics of blood clot (combination of Hb [hemoglobin], fibrin, and a higher concentration of aggregated red blood cells) formation within the hematoma of an intracerebral hemorrhage is not well understood. A quantitative neuroimaging method of localized coagulated blood volume/distribution within the hematoma might improve clinical decision-making.

METHODS

The deoxyhemoglobin of aggregated red blood cells within extravasated blood exhibits a higher magnetic susceptibility due to unpaired heme iron electrons. We propose that coagulated blood, with higher aggregated red blood cell content, will exhibit (1) a higher positive susceptibility than noncoagulated blood and (2) increase in fibrin polymerization-restricted localized diffusion, which can be measured noninvasively using quantitative susceptibility mapping and diffusion tensor imaging. In this serial magnetic resonance imaging study, we enrolled 24 patients with acute intracerebral hemorrhage between October 2021 to May 2022 at a stroke center. Patients were 30 to 70 years of age and had a hematoma volume >15 cm3 and National Institutes of Health Stroke Scale score >1. The patients underwent imaging 3×: within 12 to 24 (T1), 36 to 48 (T2), and 60 to 72 (T3) hours of last seen well on a 3T magnetic resonance imaging system. Three-dimensional anatomic, multigradient echo and 2-dimensional diffusion tensor images were obtained. Hematoma and edema volumes were calculated, and the distribution of coagulation was measured by dynamic changes in the susceptibilities and fractional anisotropy within the hematoma.

RESULTS

Using a coagulated blood phantom, we demonstrated a linear relationship between the percentage coagulation and susceptibility (R2=0.91) with a positive red blood cell stain of the clot. The quantitative susceptibility maps showed a significant increase in hematoma susceptibility (T1, 0.29±0.04 parts per millions; T2, 0.36±0.04 parts per millions; T3, 0.45±0.04 parts per millions; P<0.0001). A concomitant increase in fractional anisotropy was also observed with time (T1, 0.40±0.02; T2, 0.45±0.02; T3, 0.47±0.02; P<0.05).

CONCLUSIONS

This quantitative neuroimaging study of coagulation within the hematoma has the potential to improve patient management, such as safe resumption of anticoagulants, the need for reversal agents, the administration of alteplase to resolve the clot, and the need for surgery.

Neutrophil-to-lymphocyte ratio on admission predicts early perihematomal edema growth after intracerebral hemorrhage

Poor functional outcome is associated with perihematomal edema (PHE) expansion after intracerebral hemorrhage (ICH). The inflammatory response is crucial for the onset and progression of PHE. This study aimed to determine the connection between admission neutrophil-lymphocyte ratio (NLR) and early PHE development. We retrospectively analyzed patients with ICH admitted to the Chaohu Affiliated Hospital of Anhui Medical University from January 2021 to December 2022. The primary outcome measure was absolute PHE, defined as the volume of the follow-up PHE minus admission PHE. A semiautomated measurement tool (3D Slicer) was used to calculate the volumes of cerebral hematoma and cerebral edema. Spearman's correlation analysis determined the relationship between NLR and absolute PHE. The multiple linear regression model was constructed to analyze the predictive relation of admission NLR on early PHE expansion. A total of 117 patients were included. The median hematoma and PHE volumes on admission were 9.38 mL (interquartile range [IQR], 4.53-19.54) and 3.54 mL (IQR, 1.33-7.1), respectively. The median absolute PHE was 2.26 mL (IQR, 1.25-4.23), and the median NLR was 3.10 (IQR, 2.26-3.86). Spearman's correlation test showed a positive correlation between admission NLR and absolute PHE (r = .548, P < .001). Multiple linear regression analyses suggested that for every 1-unit increase in admission NLR (B = .176, SE = .043, Beta = .275, P < .001), there was a 0.176 mL increase in absolute PHE. Admission neutrophil-to-lymphocyte ratio (NLR) significantly and positively predicted early perihematomal edema (PHE) expansion.

Safety and efficacy of remote ischemic conditioning for spontaneous intracerebral hemorrhage (SERIC-ICH): A multicenter, randomized, parallel-controlled clinical trial study design and protocol

BACKGROUND

Previous studies have revealed that remote ischemic conditioning (RIC) may have a neuroprotective function. However, the potential benefit of RIC for patients with ICH remain unclear.

OBJECTIVE

The primary aim of this study is to assess the safety and efficacy of RIC for patients with ICH.

METHODS

The Safety and Efficacy of RIC for Spontaneous ICH (SERIC-ICH) is an ongoing prospective, randomized, multicenter, parallel-controlled, and blinded-endpoint clinical trial. The study will enroll an estimated 2000 patients aged ⩾18 years within 24 h after ICH onset, with National Institutes of Health Stroke Scale ⩾6 and Glasgow Coma Scale ⩾8 upon presentation. The patients will be randomly assigned to the RIC or control groups (1:1) and will be treated with cuffs inflated to a pressure of 200 or 60 mmHg, respectively, twice daily for 7 days. Each RIC treatment will consist of four cycles of arm ischemia for 5 min, followed by reperfusion for another 5 min, for a total procedure time of 35 min. The primary efficacy outcome measure is the proportion of patients with good functional outcomes (modified Rankin scale 0-2) at 180 days. The safety outcome measures will include all adverse events and severe adverse events occurring in the course of the study.

DISCUSSION

RIC is an inexpensive intervention and might be a strategy to improve outcomes in patients with ICH. The SERIC-ICH trial will investigate whether RIC treatment can be applied as an adjuvant treatment in the acute phase of ICH and identify safety issues.

Anakinra in cerebral haemorrhage to target secondary injury resulting from neuroinflammation (ACTION): Study protocol of a phase II randomised clinical trial

BACKGROUND

Inflammation plays a vital role in the development of secondary brain injury after spontaneous intracerebral haemorrhage (ICH). Interleukin-1 beta is an early pro-inflammatory cytokine and a potential therapeutic target.

AIM

To determine the effect of treatment with recombinant human interleukin-1 receptor antagonist anakinra on perihematomal oedema (PHO) formation in patients with spontaneous ICH compared to standard medical management, and investigate whether this effect is dose-dependent.

METHODS

ACTION is a phase-II, prospective, randomised, three-armed (1:1:1) trial with open-label treatment and blinded end-point assessment (PROBE) at three hospitals in The Netherlands. We will include 75 patients with a supratentorial spontaneous ICH admitted within 8 h after symptom onset. Participants will receive anakinra in a high dose (loading dose 500 mg intravenously, followed by infusion with 2 mg/kg/h over 72 h; n = 25) or in a low dose (loading dose 100 mg subcutaneously, followed by 100 mg subcutaneous twice daily for 72 h; n = 25), plus standard care. The control group (n = 25) will receive standard medical management.

OUTCOMES

Primary outcome is PHO, measured as oedema extension distance on MRI at day 7 ± 1. Secondary outcomes include the safety profile of anakinra, the effect of anakinra on serum inflammation markers, MRI measures of blood brain barrier integrity, and functional outcome at 90 ± 7 days.

DISCUSSION

The ACTION trial will provide insight into whether targeting interleukin-1 beta in the early time window after ICH onset could ameliorate secondary brain injury. This may contribute to the development of new treatment options to improve clinical outcome after ICH.

MiRNAs as potential therapeutic targets and biomarkers for non-traumatic intracerebral hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Hypertension is most often the cause of ICH. Less often, atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication, vitamin deficiencies, and other reasons cause hemorrhages. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. This very dangerous disease is difficult to treat, requires surgery and can lead to disability or death. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that are involved in a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., through gene repression. A growing number of studies have demonstrated miRNAs deregulation in various cardiovascular diseases, including ICH. In addition, given that computed tomography (CT) and/or magnetic resonance imaging (MRI) are either not available or do not show clear signs of possible vessel rupture, accurate and reliable analysis of circulating miRNAs in biological fluids can help in early diagnosis for prevention of ICH and prognosis patient outcome after hemorrhage. In this review, we highlight the up-to-date findings on the deregulated miRNAs in ICH, and the potential use of miRNAs in clinical settings, such as therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Acute evacuation of 54 intracerebral hematomas (aICH) during the microsurgical clipping of a ruptured middle cerebral artery bifurcation aneurysm-illustration of the individual clinical courses and outcomes with a serial brain CT/MRI panel until 12 months

PURPOSE

In aneurysmal intracerebral hemorrhage (aICH), our review showed the lack of the patient's individual (i) timeline panels and (ii) serial brain CT/MRI slice panels through the aICH evacuation and neurointensive care until the final brain tissue outcome.

METHODS

Our retrospective cohort consists of 54 consecutive aICH patients from a defined population who acutely underwent the clipping of a middle cerebral artery bifurcation saccular aneurysm (Mbif sIA) with the aICH evacuation at Kuopio University Hospital (KUH) from 2010 to 2019. We constructed the patient's individual timeline panels since the emergency call and serial brain CT/MRI slice panels through the aICH evacuation and neurointensive care until the final brain tissue outcome. The patients were indicated by numbers (1.-54.) in the pseudonymized panels, tables, results, and discussion.

RESULTS

The aICH volumes on KUH admission (median 46 cm3) plotted against the time from the emergency call to the evacuation (median 8 hours) associated significantly with the rebleeds (n=25) and the deaths (n=12). The serial CT/MRI slice panels illustrated the aICHs, intraventricular hemorrhages (aIVHs), residuals after the aICH evacuations, perihematomal edema (PHE), delayed cerebral injury (DCI), and in the 42 survivors, the clinical outcome (mRS) and the brain tissue outcome.

CONCLUSIONS

Regarding aICH evacuations, serial brain CT/MRI panels present more information than words, figures, and graphs. Re-bleeds associated with larger aICH volumes and worse outcomes. Swift logistics until the sIA occlusion with aICH evacuation is required, also in duty hours and weekends. Intraoperative CT is needed to illustrate the degree of aICH evacuation. PHE may evoke uncontrollable intracranial pressure (ICP) in spite of the acute aICH volume reduction.

More severe initial manifestations and worse short-term functional outcome of intracerebral hemorrhage in the plateau than in the plain

Intracerebral hemorrhage (ICH) is one of the most devastating forms of stroke. However, studies on ICH at high altitude are insufficient. We aimed to compare the initial manifestations, imaging features and short-term functional outcomes of ICH at different altitudes, and further explore the effect of altitude on the severity and prognosis of ICH. We retrospectively recruited ICH patients from January 2018 to July 2021 from two centers at different altitudes in China. Information regarding to clinical manifestations, neuroimages, and functional outcomes at discharge were collected and analyzed. Association between altitude and initial severity, neuroimages, and short-term prognosis of ICH were also investigated. A total of 724 patients with 400 lowlanders and 324 highlanders were enrolled. Compared with patients from the plain, those at high altitude were characterized by more severe preliminary manifestations (P < 0.0001), larger hematoma volume (P < 0.001) and poorer short-term functional outcome (P < 0.0001). High altitude was independently associated with dependency at discharge (adjusted P = 0.024), in-hospital mortality (adjusted P = 0.049) and gastrointestinal hemorrhage incidence (adjusted P = 0.017). ICH patients from high altitude suffered from more serious initial manifestations and worse short-term functional outcome than lowlanders. Control of blood pressure, oxygen supplementation and inhibition of inflammation may be critical for ICH at high altitude.

A novel mouse model of central cord syndrome

Patients with potential spinal stenosis are susceptible to central cord syndrome induced by blunt trauma. Suitable animal models are helpful for studying the pathogenesis and treatment of such injuries. In this study, we established a mouse model of acute blunt traumatic spinal cord injury by compressing the C6 spinal cord with 5 and 10 g/mm² compression weights to simulate cervical central cord syndrome. Behavioral testing confirmed that this model exhibited the characteristics of central cord syndrome because motor function in the front paws was impaired, whereas basic motor and sensory functions of the lower extremities were retained. Hematoxylin-eosin staining showed that the diseased region of the spinal cord in this mouse model was restricted to the gray matter of the central cord, whereas the white matter was rarely affected. Magnetic resonance imaging showed a hypointense signal in the lesion after mild and severe injury. In addition, immunofluorescence staining showed that the degree of nerve tract injury in the spinal cord white matter was mild, and that there was a chronic inflammation reaction. These findings suggest that this mouse model of central cord syndrome can be used as a model for preclinical research, and that gray matter is most vulnerable to injury in central cord syndrome, leading to impaired motor function.

MSCs overexpressing GDNF restores brain structure and neurological function in rats with intracerebral hemorrhage

Mesenchymal stem cells (MSCs) have been applied in transplantation to treat intracerebral hemorrhage (ICH) but with limited efficacy. Accumulated evidence has shown that glial cell-derived neurotrophic factor (GDNF) plays a crucial part in neuronal protection and functional recovery of the brain after ICH; however, GDNF has difficulty crossing the blood-brain barrier, which limits its application. In this study, we investigated the influences of MSCs overexpressing GDNF (MSCs/GDNF) on the brain structure as well as gait of rats after ICH and explored the possible mechanisms. We found that cell transplantation could reverse the neurological dysfunction and brain damage caused by ICH to a certain extent, and MSCs/GDNF transplantation was superior to MSCs transplantation. Moreover, Transplantation of MSCs overexpressing GDNF effectively reduced the volume of bleeding foci and increased the level of glucose uptake in rats with ICH, which could be related to improving mitochondrial quality. Furthermore, GDNF produced by transplanted MSCs/GDNF further inhibited neuroinflammation, improved mitochondrial quality and function, promoted angiogenesis and the survival of neurons and oligodendrocytes, and enhanced synaptic plasticity in ICH rats when compared with simple MSC transplantation. Overall, our data indicate that GDNF overexpression heightens the curative effect of MSC implantation in treating rats following ICH.

Should individual timeline and serial CT/MRI panels of all patients be presented in acute brain insult cohorts? A pilot study of 45 patients with decompressive craniectomy after aneurysmal subarachnoid hemorrhage

PURPOSE

Our review of acute brain insult articles indicated that the patients' individual (i) timeline panels with the defined time points since the emergency call and (ii) serial brain CT/MRI slice panels through the neurointensive care until death or final brain tissue outcome at 12 months or later are not presented.

METHODS

We retrospectively constructed such panels for the 45 aneurysmal subarachnoid hemorrhage (aSAH) patients with a secondary decompressive craniectomy (DC) after the acute admission to neurointensive care at Kuopio University Hospital (KUH) from a defined population from 2005 to 2018. The patients were indicated by numbers (1.-45.) in the pseudonymized panels, tables, results, and discussion. The timelines contained up to ten defined time points on a logarithmic time axis until death ([Formula: see text]; 56%) or 3 years ([Formula: see text]; 44%). The brain CT/MRI panels contained a representative slice from the following time points: SAH diagnosis, after aneurysm closure, after DC, at about 12 months (20 survivors).

RESULTS

The timelines indicated re-bleeds and allowed to compare the times elapsed between any two time points, in terms of workflow swiftness. The serial CT/MRI slices illustrated the presence and course of intracerebral hemorrhage (ICH), perihematomal edema, intraventricular hemorrhage (IVH), hydrocephalus, delayed brain injury, and, in the 20 (44%) survivors, the brain tissue outcome.

CONCLUSIONS

The pseudonymized timeline panels and serial brain imaging panels, indicating the patients by numbers, allowed the presentation and comparison of individual clinical courses. An obvious application would be the quality control in acute or elective medicine for timely and equal access to clinical care.

A systematic review and meta-analysis on the efficacy of glibenclamide in animal models of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating stroke with many mechanisms of injury. Edema worsens outcome and can lead to mortality after ICH. Glibenclamide (GLC), a sulfonylurea 1- transient receptor potential melastatin 4 (Sur1-Trpm4) channel blocker, has been shown to attenuate edema in ischemic stroke models, raising the possibility of benefit in ICH. This meta-analysis synthesizes current pre-clinical (rodent) literature regarding the efficacy of post-ICH GLC administration (vs. vehicle controls) on behaviour (i.e., neurological deficit, motor, and memory outcomes), edema, hematoma volume, and injury volume. Six studies (5 in rats and 1 in mice) were included in our meta-analysis (PROSPERO registration = CRD42021283614). GLC significantly improved behaviour (standardized mean difference (SMD) = -0.63, [-1.16, -0.09], n = 70-74) and reduced edema (SMD = -0.91, [-1.64, -0.18], n = 70), but did not affect hematoma volume (SMD = 0.0788, [-0.5631, 0.7207], n = 18-20), or injury volume (SMD = 0.2892, [-0.4950, 1.0734], n = 24). However, these results should be interpreted cautiously. Findings were conflicted with 2 negative and 4 positive reports, and Egger regressions indicated missing negative edema data (p = 0.0001), and possible missing negative behavioural data (p = 0.0766). Experimental quality assessed via the SYRCLE and CAMARADES checklists was concerning, as most studies demonstrated high risks of bias. Studies were generally low-powered (e.g., average n = 14.4 for behaviour), and future studies should employ sample sizes of 41 to detect our observed effect size in behaviour and 33 to detect our observed effect in edema. Overall, missing negative studies, low study quality, high risk of bias, and incomplete attention to key recommendations (e.g., investigating female, aged, and co-morbid animals) suggest that further high-powered confirmatory studies are needed before conclusive statements about GLC's efficacy in ICH can be made, and before further clinical trials are performed.

Predictor of the Postoperative Swelling After Craniotomy for Spontaneous Intracerebral Hemorrhage: Sphericity Index as a Novel Parameter

Objective

Spontaneous intracerebral hemorrhage is a serious type of stroke with high mortality and disability rates. Surgical treatment options vary; however, predicting edema aggravation is crucial when choosing the optimal approach. We propose using the sphericity index, a measure of roundness, to predict the aggravation of edema and guide surgical decisions.

Methods

We analyzed 56 cases of craniotomy and hematoma evacuation to investigate the correlation between the sphericity index and patient outcomes, including the need for salvage decompressive craniectomy (DC).

Results

The patients included 35 (62.5%) men and 21 (37.5%) women, with a median age of 62.5 years. The basal ganglia was the most common location of hemorrhage (50.0%). The mean hematoma volume was 86.3 cc, with 10 (17.9%) instances of hematoma expansion. Cerebral herniation was observed in 44 (78.6%) patients, intraventricular hemorrhage in 34 (60.7%), and spot signs in 9 (16.1%). Salvage DC was performed in 13 (23.6%) patients to relieve intracranial pressure. The median follow-up duration was 6 months, with a mortality rate of 12.5%. The sphericity index was significantly correlated with delayed swelling and hematoma expansion but not salvage DC.

Conclusions

The sphericity index is a promising predictor of delayed swelling and hematoma expansion that may aid in the development of surgical guidelines and medication strategies. Further large-scale studies are required to explore these aspects and establish comprehensive guidelines.

Temporal Evolution of Perihematomal Blood-Brain Barrier Compromise and Edema Growth After Intracerebral Hemorrhage

PURPOSE

The aim of this study was to investigate the temporal evolution of perihematomal blood-brain barrier (BBB) compromise and edema growth and to determine the role of BBB compromise in edema growth.

METHODS

Spontaneous intracerebral hemorrhage patients who underwent computed tomography perfusion (CTP) were divided into five groups according to the time interval from symptom onset to CTP examination. Permeability-surface area product (PS) maps were generated using CTP source images. Ipsilateral and contralateral mean PS values were computed in the perihematomal and contralateral mirror regions. The relative PS (rPS) value was calculated as a ratio of ipsilateral to contralateral PS value. Hematoma and perihematomal edema volume were determined on non-contrast CT images.

RESULTS

In the total of 101 intracerebral hemorrhage patients, the ipsilateral mean PS value was significantly higher than that in contralateral region (z = -8.284, p < 0.001). The perihematomal BBB permeability showed a course of dynamic changes including an increase in the hyperacute and acute phases, a decrease in the early subacute phase and a second increase in the late subacute phase and chronic phase. Perihematomal edema increased gradually until the late subacute phase and then slightly increased. There was a relationship between rPS value and edema volume (β = 0.254, p = 0.006).

CONCLUSION

The perihematomal BBB permeability is dynamic changes, and edema growth is gradually increased in patients following intracerebral hemorrhage. BBB compromise plays an essential role in edema growth. The quantitative assessment of BBB compromise may provide valuable information in therapeutic interventions of intracerebral hemorrhage patients.

Fever burden within 24 h after hematoma evacuation predicts early neurological deterioration in patients with intracerebral hemorrhage: a retrospective analysis

Background

Early neurological deterioration after hematoma evacuation is closely associated with a poor prognosis in patients with intracerebral hemorrhage. However, the relationship between body temperature after hematoma evacuation and early neurological deterioration remains unclear. Therefore, this study aims to explore the possible relationship between body temperature and early neurological deterioration in patients with intracerebral hemorrhage after hematoma evacuation.

Methods

We retrospectively collected data from patients with cerebral hemorrhage at our institute between January 2017 and April 2022. The Student's t-test, Mann-Whitney U-test, and χ2 Test and Fisher's exact test were used to analyze the clinical baseline data. A univariate logistic regression model was used to evaluate the association between the body temperature indices and early neurological deterioration. The predictive power was assessed using the area under the Receiver Operating Characteristic (ROC) curve. The secondary outcome was a poor functional outcome.

Results

Among 2,726 patients with intracerebral hemorrhage, 308 who underwent hematoma evacuation were included in the present analysis. A total of 82 patients (22.6%) developed early neurological deterioration. Univariate analysis showed that sex (p = 0.041); body temperature at 6 h (p = 0.005), 12 h (p = 0.01), and 24 h (p = 0.008) after surgery; duration of fever (p = 0.008); and fever burden (p < 0.001) were associated with early neurological deterioration. Multivariate logistic regression showed that fever burden was independently associated with early neurological deterioration (OR = 1.055 per °C × hour, 95%CI 1.008-1.103, p = 0.020). ROC showed that fever burden (AUC = 0.590; 95%CI: 0.514-0.666) could predict the occurrence of early neurological deterioration.

Conclusion

Fever burden is associated with early neurological deterioration in intracerebral hemorrhage patients undergoing hematoma evacuation. Our findings add to previous evidence on the relationship between the fever burden and the occurrence of early neurological deterioration in patients with intracerebral hemorrhage. Future studies with larger sample sizes are required to confirm these findings.

The Osaka prognostic score and Naples prognostic score: novel biomarkers for predicting short-term outcomes after spontaneous intracerebral hemorrhage

OBJECTIVES

Poor immune-nutritional status has been associated with an unfavorable outcome in critical illness. The Osaka prognostic score (OPS) and the Naples prognostic score (NPS), based on inflammatory and nutritional status, has been shown to predict prognosis following cancer and other diseases. The aim of this study was to investigate the relationship between the OPS and NPS and the short-term outcomes of patients with intracerebral hemorrhage (ICH).

METHODS

We retrospectively analyzed the clinical data of patients hospitalized with spontaneous ICH (n = 340) at The Second Affiliated Hospital of Chongqing Medical University between August 2016 and August 2021. Inclusion criteria included patients aged between 18 and 70, and if a blood sample was taken for laboratory testing within 24 h of admission (serum C-reactive protein, albumin, total cholesterol, and counts for neutrophils, lymphocytes, and monocytes were collected on admission). Exclusion criteria included a non-spontaneous cause of ICH and patient death during hospitalization. Patients were divided into four groups based on OPS or five groups according to NPS. Outcomes were evaluated by the modified Rankin Scale (mRS) at six months post-ICH hospitalization. An unfavorable outcome was defined as a mRS score ≥ 3.

RESULTS

A total of 289 patients met our inclusion criteria. The unfavorable outcome group had older age, a lower Glasgow Coma Scale score, a higher rate of complications and cerebral herniation, a longer hospital stay, and higher OPS and NPS when compared with the favorable outcome group. Univariate analysis showed that both OPS and NPS were strongly correlated with mRS (r = 0.196,P < 0.001; r = 0.244, P = 0.001, respectively). Multivariate analysis further showed that OPS and NPS were both independent predictors of unfavorable outcomes for patients with ICH with adjusted odds ratios of 1.802 (95% confidence interval [CI]:1.140-2.847, P = 0.012) and 1.702 (95% CI: 1.225-2.635, P = 0.02), respectively. The area under the curve (AUC) of NPS for predicting a poor outcome was 0.732 (95% CI: 0.665-0.799), which was similar to the AUC of OPS 0.724 (95% CI: 0.657-0.792).

CONCLUSIONS

In this cohort, a higher OPS and NPS on admission was associated with poor outcome at six months following ICH, supporting their potential role as markers for predicting the outcome of patients with ICH.

The association between perihaematomal oedema and functional outcome after spontaneous intracerebral haemorrhage: A systematic review and meta-analysis

PURPOSE

Perihaematomal oedema (PHO) formation has gained increasing interest as a therapeutic target after spontaneous intracerebral haemorrhage (ICH). Whether PHO contributes to poor outcome is unclear. We aimed to determine the association between PHO and outcome in patients with spontaneous ICH.

METHOD

We searched five databases up to 17 November 2021 for studies of ⩾10 adults with ICH reporting the presence of PHO and outcome. We assessed risk of bias, extracted aggregate data and used random effects meta-analysis to pool studies that reported odds ratios (OR) with 95% confidence intervals (CI). Primary outcome was poor functional outcome defined as modified Rankin Scale score of 3-6 at 3 months. Additionally, we assessed PHO growth and poor outcome at any time of follow-up. We prospectively registered the protocol in PROSPERO (CRD42020157088).

FINDINGS

We identified 12,968 articles, of which we included 27 studies (n = 9534). Eighteen studies reported an association between larger PHO volume and poor outcome, six a neutral result and three an inverse relationship. Larger absolute PHO volume was associated with poor functional outcome at 3 months (OR per mL increase of absolute PHO 1.03, 95% CI 1.00-1.06, I2 44%, four studies). Additionally, PHO growth was associated with poor outcome (OR 1.04, 95% CI 1.02-1.06, I2 0%, seven studies).

DISCUSSION

In patients with spontaneous ICH, larger PHO volume is associated with poor functional outcome at 3 months. These findings support the development and investigation of new therapeutic interventions targeting PHO formation to evaluate if reduction of PHO improves outcome after ICH.

The efficacy of stereotactic minimally invasive thrombolysis at different catheter positions in the treatment of small- and medium-volume basal ganglia hemorrhage (SMITDCP I): a randomized, controlled, and blinded endpoint phase 1 trial

Objective

The aim of this study was to evaluate the effects of stereotactic minimally invasive puncture with different catheter placement positions when combined with urokinase thrombolysis for the treatment of small- and medium-volume basal ganglia hemorrhage. Our goal was to identify the best minimally invasive catheter placement position to enhance therapeutic efficacy for patients with cerebral hemorrhage.

Methods

The stereotactic minimally invasive thrombolysis at different catheter positions in the treatment of small- and medium-volume basal ganglia hemorrhage (SMITDCPI) was a randomized, controlled, and endpoint phase 1 trial. We recruited patients with spontaneous ganglia hemorrhage (medium-to-small and medium volume) who were treated in our hospital. All patients received stereotactic, minimally invasive punctures combined with an intracavitary thrombolytic injection of urokinase hematoma. A randomized number table method was used to divide the patients into two groups concerning the location of catheterization: a penetrating hematoma long-axis group and a hematoma center group. The general conditions of the two groups of patients were compared, and the data were analyzed, including the time of catheterization, the dosage of urokinase, the amount of residual hematoma, the hematoma clearance rate, complications, and the National Institute of Health stroke scale (NIHSS) score data at 1 month after surgery.

Results

Between June 2019 and March 2022, 83 patients were randomly recruited and assigned to the two groups as follows: 42 cases (50.60%) to the penetrating hematoma long-axis group and 41 cases (49.40%) to the hematoma center group. Compared with the hematoma center group, the long-axis group was associated with a significantly shorter catheterization time, a lower urokinase dose, a lower residual hematoma volume, a higher hematoma clearance rate, and fewer complications (P < 0.05). However, there were no significant differences between the two groups in terms of the NIHSS scores when tested 1 month after surgery (P > 0.05).

Conclusion

Stereotactic minimally invasive puncture combined with urokinase for the treatment of small- and medium-volume hemorrhage in the basal ganglia, including catheterization through the long axis of the hematoma, led to significantly better drainage effects and fewer complications. However, there was no significant difference in short-term NIHSS scores between the two types of catheterization.

NPAS4 Exacerbates Pyroptosis via Transcriptionally Regulating NLRP6 in the Acute Phase of Intracerebral Hemorrhage in Mice

Intracerebral hemorrhage (ICH) is a severe cerebrovascular disease with a high disability rate and high mortality, and pyroptosis is a type of programmed cell death in the acute phase of ICH. Neuronal Per-Arnt-Sim domain protein 4 (Npas4) is a specific transcription factor highly expressed in the nervous system, yet the role of NPAS4 in ICH-induced pyroptosis is not fully understood. NLR family Pyrin-domain-containing 6 (NLRP6), a new member of the Nod-like receptor family, aggravates pyroptosis via activating cysteine protease-1 (Caspase-1) and Caspase-11. In this study, we found that NPAS4 was upregulated in human and mouse peri-hematoma brain tissues and peaked at approximately 24 h after ICH modeling. Additionally, NPAS4 knockdown improved neurologic dysfunction and brain damage induced by ICH in mice after 24 h. Meanwhile, inhibiting NPAS4 expression reduced the levels of myeloperoxidase (MPO)-positive cells and Caspase-1/TUNEL-double-positive cells and decreased cleaved Caspase-1, cleaved Caspase-11, and N-terminal GSDMD levels. Consistently, NPAS4 overexpression reversed the above alternations after ICH in the mice. Moreover, NPAS4 could interact with the Nlrp6 promoter region (-400--391 bp and -33--24 bp) and activate the transcription of Nlrp6. Altogether, our study demonstrated that NPAS4, as a transcription factor, can exacerbate pyroptosis and transcriptionally activate NLRP6 in the acute phase of intracerebral hemorrhage in mice.

Intranasal Delivery of Gene-Edited Microglial Exosomes Improves Neurological Outcomes after Intracerebral Hemorrhage by Regulating Neuroinflammation

Neural inflammatory response is a crucial pathological change in intracerebral hemorrhage (ICH) which accelerates the formation of perihematomal edema and aggravates neural cell death. Although surgical and drug treatments for ICH have advanced rapidly in recent years, therapeutic strategies that target and control neuroinflammation are still limited. Exosomes are important carriers for information transfer among cells. They have also been regarded as a promising therapeutic tool in translational medicine, with low immunogenicity, high penetration through the blood-brain barrier, and ease of modification. In our previous research, we have found that exogenous administration of miRNA-124-overexpressed microglial exosomes (Exo-124) are effective in improving post-injury cognitive impairment. From this, we evaluated the potential therapeutic effects of miRNA-124-enriched microglial exosomes on the ICH mice in the present study. We found that the gene-edited exosomes could attenuate neuro-deficits and brain edema, improve blood-brain barrier integrity, and reduce neural cell death. Moreover, the protective effect of Exo-124 was abolished in mice depleted of Gr-1⁺ myeloid cells. It suggested that the exosomes exerted their functions by limiting the infiltration of leukocyte into the brain, thus controlling neuroinflammation following the onset of ICH. In conclusion, our findings provided a promising therapeutic strategy for improving neuroinflammation in ICH. It also opens a new avenue for intranasal delivery of exosome therapy using miRNA-edited microglial exosomes.

Cytotoxic Edema and Adverse Clinical Outcomes in Patients with Intracerebral Hemorrhage

BACKGROUND

Cytotoxic edema (CE) is an important form of perihematomal edema (PHE), which is a surrogate marker of secondary injury after intracerebral hemorrhage (ICH). However, knowledge about CE after ICH is insufficient. Whether CE has adverse effects on clinical outcomes of patients with ICH remains unknown. Therefore, we aimed to investigate the temporal pattern of CE and its association with clinical outcomes in patients with ICH.

METHODS

Data were derived from a randomized controlled study (comparing the deproteinized calf blood extract with placebo in patients with ICH). Intervention in this original study did not show any impact on hematoma and PHE volume, presence of CE, or clinical outcomes. We conducted our analysis in 20 patients who underwent magnetic resonance imaging with diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) images at day 3 and within 7-12 days after symptom onset. CE was defined as an elevated DWI b1000 signal and an ADC value reduced by > 10% compared with the mirror area of interest in the perihematomal region. The modified Rankin Scale (mRS), National Institutes of Health Stroke Scale (NIHSS), and Barthel Index (BI) were performed face to face at 30-day and 90-day follow-ups after ICH onset to assess the clinical outcomes of the patients.

RESULTS

CE was detected in nearly two thirds of patients with ICH in our study and seemed to be reversible. CE within 7-12 days, rather than at day 3 after symptom onset, was associated with poor clinical outcome (mRS 3-6) at the 30-day follow-up (P = 0.020). In addition, compared with those without CE, patients with CE within 7-12 days had more severe neurological impairment measured by NIHSS score (P = 0.024) and worse daily life quality measured by BI (P = 0.004) at both the 30- and 90-day follow-ups.

CONCLUSIONS

CE appears in the acute phase of ICH and might be reversible. CE within 7-12 days post ICH was related to poor outcomes, which provides a novel therapeutic target for ICH intervention.

The association between blood pressure variability and perihematomal edema after spontaneous intracerebral hemorrhage

Background

Perihematomal edema (PHE) after spontaneous intracerebral hemorrhage (sICH) is associated with clinical deterioration, but the etiology of PHE development is only partly understood.

Aims

We aimed to investigate the association between systemic blood pressure (BP) variability (BPV) and formation of PHE.

Methods

From a multicenter prospective observational study, we selected patients with sICH who underwent 3T brain MRI within 21 days after sICH, and had at least 5 BP measurements available in the first week after sICH. Primary outcome was the association between coefficient of variation (CV) of systolic BP (SBP) and edema extension distance (EED) using multivariable linear regression, adjusting for age, sex, ICH volume and timing of the MRI. In addition, we investigated the associations of mean SBP, mean arterial pressure (MAP), their CVs with EED and absolute and relative PHE volume.

Results

We included 92 patients (mean age 64 years; 74% men; median ICH volume 16.8 mL (IQR 6.6–36.0), median PHE volume 22.5 mL (IQR 10.2–41.4). Median time between symptom onset and MRI was 6 days (IQR 4–11), median number of BP measurements was 25 (IQR 18–30). Log-transformed CV of SBP was not associated with EED (B = 0.050, 95%-CI −0.186 to 0.286, p = 0.673). Furthermore, we found no association between mean SBP, mean and CV of MAP and EED, nor between mean SBP, mean MAP or their CVs and absolute or relative PHE.

Discussion

Our results do not support a contributing role for BPV on PHE, suggesting mechanisms other than hydrostatic pressure such as inflammatory processes, may play a more important role.

Ozanimod-Dependent Activation of SIRT3/NF-κB/AIM2 Pathway Attenuates Secondary Injury After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is characterized by poor prognosis and high mortality rates. To date, satisfactory therapeutic approaches for ICH remain limited, so it is urgently needed to develop a safer and more effective prescription. Secondary inflammatory response has been acknowledged as an aggravating factor to neurological deterioration after ICH. As a component of inflammasome sensors, absent in melanoma 2 (AIM2) plays an important role in the neuroinflammation process. Here, ozanimod, a novel selective sphingosine 1-phosphate receptor modulator, has gained much attention, which alleviates the resultant neuroinflammation and improves functional recovery derived from ICH. In this study, ozanimod improved neurological functions of ICH mice via reduction of hematoma size. Furthermore, both microglial and AIM2 inflammasome activations were reversed by ozanimod, which are confirmed by the downregulation of related inflammatory proteins and cytokines (IL-1β, IL-6, and TNF-α), coupled with the upregulation of SIRT3, by leveraging the Western blot and enzyme-linked immunosorbent assay. Additionally, we find that ozanimod decreases nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression. Notably, in vitro cell experiments induced by lipopolysaccharide confirms that the anti-inflammatory effect of ozanimod could be abolished by the SIRT3 inhibitor. In conclusion, these results indicate that ozanimod mitigates ICH-induced secondary inflammatory responses by modulating AIM2 inflammasome mediated by SIRT3/NF-κB/AIM2 pathway. This demonstrates ozanimod orchestrates ICH-induced neuroinflammation and could be a targeted therapy for improving prognosis of ICH.