Intracerebral haemorrhage: mechanisms of injury and therapeutic targets

Surgical Robotics for Intracerebral Hemorrhage Treatment: State of the Art and Future Directions

Intracerebral hemorrhage (ICH) is a stroke subtype with high mortality and disability, and there are no proven medical treatments that can improve the functional outcome of ICH patients. Robot-assisted neurosurgery is a significant advancement in the development of minimally invasive surgery for ICH. This review encompasses the latest advances and future directions of surgical robots for ICH. First, three robotic systems for neurosurgery applied to ICH are illustrated. Second, the key technologies of robot-assisted surgery for ICH are introduced in aspects of stereotactic technique and navigation, the puncture instrument, and hematoma evacuation. Finally, the limitations of current surgical robots are summarized, and the possible development direction is discussed, which is named "multisensor fusion and intelligent aspiration control of minimally invasive surgical robot for ICH". It is expected that the new generation of surgical robots for ICH will facilitate quantitative, precise, individualized, standardized treatment strategies for ICH.

The effect of neutrophil-to-lymphocyte ratio and systemic inflammatory response on perihematomal edema after intracerebral hemorrhage

BACKGROUND

Perihematomal edema (PHE) is a marker of secondary brain injury in patients with intracerebral hemorrhage (ICH) and is associated with increased inflammatory markers and neurological disability. This study aims to assess the effect of the neutrophile-to-lymphocyte ratio (NLR) and systemic inflammatory response syndrome (SIRS) on PHE measurements and functional status in patients with ICH.

METHODS

We included 215 patients with primary ICH and the primary outcomes were absolute and relative PHE, and edema extension distance (EED). A favorable functional outcome was defined as a modified Rankin Scale (mRS) score 0-2 measured 3 months after ICH.

RESULTS

Median age was 73.0 years (interquartile range 66-80) and 54.4% patients were males. Fifty-nine patients were functionally independent at 90 days (mRS 0 to 2). NLR and SIRS were not predictors of absolute, relative PHE, and EED when adjusted for multiple confounders. However, admission NLR was independently associated with an unfavorable functional outcome at 90 days (aOR = 0.38; 95% CI 0.17-0.87; p = 0.021).

CONCLUSIONS

NLR and SIRS are not independent predictors of absolute and relative PHE measurements following ICH. Nevertheless, NLR predicts long-term disability in ICH patients. Further research is needed to understand the mechanisms by which inflammation causes neurological injury in ICH.

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.

Exosomes from young healthy human plasma promote functional recovery from intracerebral hemorrhage via counteracting ferroptotic injury

Intracerebral hemorrhage (ICH), as a type of life-threatening and highly disabled disease, has limited therapeutic approaches. Here, we show that exosomes derived from young healthy human plasma exhibiting typical exosomes features could facilitate functional recovery of ICH mice. When these exosomes are intraventricularly delivered into the brain after ICH, they mainly distribute around the hematoma and could be internalized by neuronal cells. Strikingly, exosomes administration markedly enhanced the behavioral recovery of ICH mice through reducing brain injury and cell ferroptosis. MiRNA sequencing revealed that microRNA-25-3p (miR-25-3p) was differentially expressed miRNA in the exosomes from young healthy human plasma, compared with exosomes from the old control. Importantly, miR-25-3p mimicked the treatment effect of exosomes on behavioral improvement, and mediated the neuroprotective effect of exosomes against ferroptosis in ICH. Furthermore, luciferase assay and western blotting data illustrated that P53 as assumed the role of a downstream effector of miR-25-3p, thereby regulating SLC7A11/GPX4 pathway to counteract ferroptosis. Taken together, these findings firstly reveal that exosomes from young healthy human plasma improve functional recovery through counteracting ferroptotic injury by regulating P53/SLC7A11/GPX4 axis after ICH. Given the easy availability of plasma exosomes, our study provides a potent therapeutic strategy for ICH patients with quick clinical translation in the near future.

Purinergic neurotransmission receptor P2X4 silencing alleviates intracerebral hemorrhage-induced neuroinflammation by blocking the NLRP1/Caspase-1 pathway

This study is performed to explore the role of P2X4 in intracerebral hemorrhage (ICH) and the association between P2X4 and the NLRP1/Caspase-1 pathway. The mouse ICH model was established via collagenase injection into the right basal ganglia. P2X4 expression in brain tissues was knocked down via intracerebroventricular injection with adeno-associated virus (AAV) harboring shRNA against shP2X4. The gene expression of P2X4 and protein levels related to NLRP1 inflammasome were detected using qRT-PCR and Western blot analysis, respectively. Muramyl dipeptide (an activator of NLRP1) was used to activate NLRP1 in brain tissues. ICH induced high expression of P2X4 in mouse brain tissues. The knockdown of P2X4 alleviated short- and long-term neurological deficits of ICH mice, as well as inhibited the tissue expression and serum levels of pro-inflammatory cytokines, including TNF-α, interleukin (IL)-6, and IL-1β. Additionally, the expressions of NLRP1, ASC, and pro-Caspase-1 were down-regulated upon P2X4 silencing. Moreover, neurological impairment and the expression and secretion of cytokines after P2X4 silencing were aggravated by the additional administration of MDP. P2X4 knockdown represses neuroinflammation in brain tissues after ICH. Mechanistically, P2X4 inhibition exerts a neuroprotective effect in ICH by blocking the NLRP1/Caspase-1 pathway.

Using Radiomics and Convolutional Neural Networks for the Prediction of Hematoma Expansion After Intracerebral Hemorrhage

Background

Hematoma enlargement (HE) is a common complication following acute intracerebral hemorrhage (ICH) and is associated with early deterioration and unfavorable clinical outcomes. This study aimed to evaluate the predictive performance of a computed tomography (CT) based model that utilizes deep learning features in identifying HE.

Methods

A total of 408 patients were retrospectively enrolled between January 2015 and December 2020 from our institution. We designed an automatic model that could mask the hematoma area and fusion features of radiomics, clinical data, and convolutional neural network (CNN) in a hybrid model. We assessed the model's performance by using confusion matrix metrics (CM), the area under the receiver operating characteristics curve (AUC), and other statistical indicators.

Results

After automated masking, 408 patients were randomly divided into two cohorts with 204 patients in the training set and 204 patients in the validation set. The first cohort trained the CNN model, from which we then extracted radiomics, clinical data, and CNN features for the second validation cohort. After feature selection by K-highest score, a support vector machines (SVM) model classification was used to predict HE. Our hybrid model exhibited a high AUC of 0.949, and 0.95 of precision, 0.83 of recall, and 0.94 of average precision (AP). The CM found that only 5 cases were misidentified by the model.

Conclusion

The automatic hybrid model we developed is an end-to-end method and can assist in clinical decision-making, thereby facilitating personalized treatment for patients with ICH.

H3K9 trimethylation dictates neuronal ferroptosis through repressing Tfr1

Spontaneous intracerebral hemorrhage (ICH) is a devastating disease with high morbidity and mortality worldwide. We have previously shown that ferroptosis contributes to neuronal loss in ICH mice. The overload of iron and dysfunction of glutathione peroxidase 4 (GPx4) promote neuronal ferroptosis post-ICH. However, how epigenetic regulatory mechanisms affect the ferroptotic neurons in ICH remains unclear. In the current study, hemin was used to induce ferroptosis in N2A and SK-N-SH neuronal cells to mimic ICH. The results showed that hemin-induced ferroptosis was accompanied by an increment of global level of trimethylation in histone 3 lysine 9 (H3K9me3) and its methyltransferase Suv39h1. Transcriptional target analyses indicated that H3K9me3 was enriched at the promoter region and gene body of transferrin receptor gene 1 (Tfr1) and repressed its expression upon hemin stimulation. Inhibition of H3K9me3 with inhibitor or siRNA against Suv39h1 aggravated hemin- and RSL3-induced ferroptosis by upregulating Tfr1 expression. Furthermore, Suv39h1-H3K9me3 mediated repression of Tfr1 contributes to the progression of ICH in mice. These data suggest a protective role of H3K9me3 in ferroptosis post ICH. The knowledge gained from this study will improve the understanding of epigenetic regulation in neuronal ferroptosis and shed light on future clinical research after ICH.

Temporal dynamics of microglia-astrocyte interaction in neuroprotective glial scar formation after intracerebral hemorrhage

The role of glial scar after intracerebral hemorrhage (ICH) remains unclear. This study aimed to investigate whether microglia-astrocyte interaction affects glial scar formation and explore the specific function of glial scar. We used a pharmacologic approach to induce microglial depletion during different ICH stages and examine how ablating microglia affects astrocytic scar formation. Spatial transcriptomics (ST) analysis was performed to explore the potential ligand-receptor pair in the modulation of microglia-astrocyte interaction and to verify the functional changes of astrocytic scars at different periods. During the early stage, sustained microglial depletion induced disorganized astrocytic scar, enhanced neutrophil infiltration, and impaired tissue repair. ST analysis indicated that microglia-derived insulin like growth factor 1 (IGF1) modulated astrocytic scar formation via mechanistic target of rapamycin (mTOR) signaling activation. Moreover, repopulating microglia (RM) more strongly activated mTOR signaling, facilitating a more protective scar formation. The combination of IGF1 and osteopontin (OPN) was necessary and sufficient for RM function, rather than IGF1 or OPN alone. At the chronic stage of ICH, the overall net effect of astrocytic scar changed from protective to destructive and delayed microglial depletion could partly reverse this. The vital insight gleaned from our data is that sustained microglial depletion may not be a reasonable treatment strategy for early-stage ICH. Inversely, early-stage IGF1/OPN treatment combined with late-stage PLX3397 treatment is a promising therapeutic strategy. This prompts us to consider the complex temporal dynamics and overall net effect of microglia and astrocytes, and develop elaborate treatment strategies at precise time points after ICH.

Piezo1 suppression reduces demyelination after intracerebral hemorrhage

Piezo1 is a mechanically-gated calcium channel. Recent studies have shown that Piezo1, a mechanically-gated calcium channel, can attenuate both psychosine- and lipopolysaccharide-induced demyelination. Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage, in this study, we investigated the role of Piezo1 in intracerebral hemorrhage. We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon (within 48 hours) after intracerebral hemorrhage, primarily in oligodendrocytes. Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema, myelin sheath loss, and degeneration in injured tissue, a substantial reduction in oligodendrocyte apoptosis, and a significant improvement in neurological function. In addition, we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway. These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage, as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath, thereby improving neuronal function after intracerebral hemorrhage.

Tripartite Motif Protein Family in Central Nervous System Diseases

Tripartite motif (TRIM) protein superfamily is a group of E3 ubiquitin ligases characterized by the conserved RING domain, the B-box domain, and the coiled-coil domain (RBCC). It is widely involved in various physiological and pathological processes, such as intracellular signal transduction, cell cycle regulation, oncogenesis, and innate immune response. Central nervous system (CNS) diseases are composed of encephalopathy and spinal cord diseases, which have a high disability and mortality rate. Patients are often unable to take care of themselves and their life quality can be seriously declined. Initially, the function research of TRIM proteins mainly focused on cancer. However, in recent years, accumulating attention is paid to the roles they play in CNS diseases. In this review, we integrate the reported roles of TRIM proteins in the pathological process of CNS diseases and related signaling pathways, hoping to provide theoretical bases for further research in treating CNS diseases targeting TRIM proteins. TRIM proteins participated in CNS diseases. TRIM protein family is characterized by a highly conserved RBCC domain, referring to the RING domain, the B-box domain, and the coiled-coil domain. Recent research has discovered the relations between TRIM proteins and various CNS diseases, especially Alzheimer's disease, Parkinson's disease, and ischemic stroke.

Association of lactate-to-albumin ratio with in-hospital and intensive care unit mortality in patients with intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) is a severe stroke subtype with a high mortality rate; the lactate-to-albumin ratio (LAR) is a new biomarker for predicting clinical outcomes in patients with ICH. However, the relationship between LAR and mortality in patients with ICH treated in the intensive care unit (ICU) remains controversial. Therefore, in this study, we aimed to investigate the association between LAR and in-hospital and ICU mortality in patients with ICH.

Methods

Patients with ICH were selected from the Medical Information Mart for Intensive Care III (MIMIC-III) database; their clinical information, including baseline characteristics, vital signs, comorbidities, laboratory test results, and scoring systems, was extracted. Univariate and multivariate Cox proportional hazards analyses were used to investigate the association of LAR with in-hospital and ICU mortality. The maximum selection statistical method and subgroup analysis were used to investigate these relationships further. Kaplan-Meier (KM) analysis was used to draw survival curves.

Results

This study enrolled 237 patients with ICH whose lactate and albumin levels, with median values of 1.975 and 3.6 mg/dl, respectively, were measured within the first 24 h after ICU admission. LAR had an association with increased risk of in-hospital mortality [unadjusted hazards ratio (HR), 1.79; 95% confidence interval (CI), 1.32-2.42; p < 0.001] and ICU mortality (unadjusted HR, 1.88; 95% CI, 1.38-2.55; p < 0.001). A cut-off value of 0.963 mg/dl was used to classify patients into high LAR (≥0.963) and low LAR (<0.963) groups, and survival curves suggested that those two groups had significant survival differences (p = 0.0058 and 0.0048, respectively). Furthermore, the high LAR group with ICH had a significantly increased risk of in-hospital and ICU mortality compared to the low LAR group.

Conclusion

Our study suggests that a high LAR is associated with an increased risk of in-hospital and ICU mortality in patients with ICH. Thus, the LAR is a useful prognostic predictor of clinical outcomes in patients with ICH.

A review of invasive intracranial pressure monitoring following surgery for hypertensive cerebral hemorrhage

Hypertensive cerebral hemorrhage, the most common prevalent of spontaneous cerebral hemorrhage, poses a significant threat to patient mortality and morbidity, while therapeutic options remain limited, making the disease a burden not only for patients' families but also a major challenge for national healthcare systems. The elevation of intracranial pressure subsequent to hypertensive cerebral hemorrhage is a critical contributor to mortality. However, it often manifests before the onset of clinical symptoms, which are typically atypical, leading to delayed treatment and irreversible consequences for the patient. Hence, early detection of intracranial pressure variations can aid in timely, efficient, and precise treatment, reducing patient mortality. Invasive intracranial pressure monitoring enables real-time, accurate monitoring of intracranial pressure changes, providing clinicians with therapeutic guidance and overcoming the limitations of empirical treatment. This article aims to review the use of invasive intracranial pressure monitoring in postoperative hypertensive cerebral hemorrhage and hopes to contribute to clinical and scientific research.

Systemic Inflammation after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is one of the most severe neurological disorders, with a high mortality rate and severe disabling functional sequelae. Systemic inflammation following hemorrhagic stroke may play an important role in mediating intracranial and extracranial tissue damage. Previous studies showed that various systemic inflammatory biomarkers might be useful in predicting clinical outcomes. Anti-inflammatory treatment might be a promising therapeutic approach for improving the prognosis of patients with aSAH. This review summarizes the complicated interactions between the nervous system and the immune system.

Neutrophil percentage to albumin ratio is associated with stroke-associated pneumonia and poor outcome in patients with spontaneous intracerebral hemorrhage

Background

The purpose of this study was to investigate the diagnostic performance of the neutrophil percentage-to-albumin ratio (NPAR) for predicting stroke-associated pneumonia (SAP) and functional outcome in patients with intracerebral hemorrhage (ICH).

Methods

We analyzed our prospective database of consecutive ICH patients who were admitted to the First Affiliated Hospital of Chongqing Medical University from January 2016 to September 2021. We included subjects with a baseline computed tomography available and a complete NPAR count performed within 6h of onset. The patients' demographic and radiological characteristics were analyzed. Good outcome was defined as a modifed Rankin Scale score of 0-3 at 90 days. Poor outcome was defined as a modifed Rankin Scale score of 4-6 at 90 days. Multivariable logistic regression models were used to investigate the association between NPAR, SAP, and functional outcome. Receiver operating characteristic (ROC) curve analysis was conducted to identify the optimal cutoff of NPAR to discriminate between good and poor outcomes in ICH patients.

Results

A total of 918 patients with ICH confirmed by non-contrast computed tomography were included. Of those, 316 (34.4%) had SAP, and 258 (28.1%) had poor outcomes. Multivariate regression analysis showed that higher NPAR on admission was an independent predictor of SAP (adjusted odds ratio: 2.45; 95% confidence interval, 1.56-3.84; P<0.001) and was associated with increased risk of poor outcome (adjusted odd ratio:1.72; 95% confidence interval, 1.03-2.90; P=0.040) in patients with ICH. In ROC analysis, an NPAR of 2 was identified as the optimal cutoff value to discriminate between good and poor functional outcomes.

Conclusion

Higher NPAR is independently associated with SAP and poor functional outcome in patients with ICH. Our findings suggest that early prediction of SAP is feasible by using a simple biomarker NPAR.

Induction Mechanism of Ferroptosis, Necroptosis, and Pyroptosis: A Novel Therapeutic Target in Nervous System Diseases

In recent years, three emerging cell deaths, ferroptosis, necroptosis and pyroptosis, have gradually attracted everyone's attention, and they also play an important role in the occurrence and development of various diseases. Ferroptosis is an idiographic iron-dependent form regulated cell death with the hallmark of accumulation of the intracellular reactive oxygen species (ROS). Necroptosis is a form of regulated necrotic cell death mediated by the receptor-interacting protein kinase 1(RIPK1) and receptor-interacting protein kinase 3RIPK3. Pyroptosis, also known as cell inflammatory necrosis, is a programmed cell necrosis mediated by Gasdermin D (GSDMD). It is manifested by the continuous swelling of the cells until the cell membrane ruptures, resulting in the release of the cell contents and the activation of a strong inflammatory response. Neurological disorders remain a clinical challenge and patients do not respond well to conventional treatments. Nerve cell death can aggravate the occurrence and development of neurological diseases. This article reviews the specific mechanisms of these three types of cell death and their relationship with neurological diseases and the evidence for the role of the three types of cell death in neurological diseases; understanding these pathways and their mechanisms is helpful for the treatment of neurological diseases.

Long non-coding RNAs in intracerebral hemorrhage

Intracerebral hemorrhage (ICH), a subtype of stroke, can lead to long-term disability and is one of the leading causes of death. Unfortunately, the effectiveness of pharmacological therapy for ICH is still uncertain. Long non-coding RNA (lncRNA) was defined as an RNA molecule that consists of more than 200 nt without translational activity. As a vital class of diverse molecules, lncRNAs are involved in developmental and pathological processes and have been attractive for decades. LncRNAs have also become potential targets for therapies, as they were massively identified and profiled. In particular, emerging evidence has revealed the critical role of lncRNAs in ICH while attempts were made to treat ICH via regulating lncRNAs. But the latest evidence remains to be summarized. Thus, in this review, we will summarize the recent advances in lncRNA in ICH, highlighting the regulatory role of lncRNAs and their potential as therapeutic targets.

CD4+ T cells aggravate hemorrhagic brain injury

Leukocyte infiltration accelerates brain injury following intracerebral hemorrhage (ICH). Yet, the involvement of T lymphocytes in this process has not been fully elucidated. Here, we report that CD4⁺ T cells accumulate in the perihematomal regions in the brains of patients with ICH and ICH mouse models. T cells activation in the ICH brain is concurrent with the course of perihematomal edema (PHE) development, and depletion of CD4⁺ T cells reduced PHE volumes and improved neurological deficits in ICH mice. Single-cell transcriptomic analysis revealed that brain-infiltrating T cells exhibited enhanced proinflammatory and proapoptotic signatures. Consequently, CD4⁺ T cells disrupt the blood-brain barrier integrity and promote PHE progression through interleukin-17 release; furthermore, the TRAIL-expressing CD4⁺ T cells engage DR5 to trigger endothelial death. Recognition of T cell contribution to ICH-induced neural injury is instrumental for designing immunomodulatory therapies for this dreadful disease.

Zhilong Huoxue Tongyu capsule attenuates intracerebral hemorrhage induced redox imbalance by modulation of Nrf2 signaling pathway

Background: One of the severely debilitating and fatal subtypes of hemorrhagic stroke is intracerebral hemorrhage (ICH), which lacks an adequate cure at present. The Zhilong Huoxue Tongyu (ZLHXTY) capsule has been utilized effectively since last decade to treat ICH, in some provinces of China but the scientific basis for its mechanism is lacking. Purpose: To investigate the neuroprotective role of ZLHXTY capsules for ICH-induced oxidative injury through the regulation of redox imbalance with the Nrf2 signaling pathway. Methods: Autologous blood injection model of ICH in C57BL/6J mice was employed. Three treatment groups received ZLHXTY once daily through oral gavage at doses 0.35 g/kg, 0.7 g/kg, and 1.4 g/kg, started after 2 h and continued for 72 h of ICH induction. The neurological outcome was measured using a balance beam test. Serum was tested for inflammatory markers IL-1β, IL-6, and TNF-α through ELISA, oxidative stress through hydrogen peroxide content assay, and antioxidant status by total antioxidant capacity (T-AOC) assay. Nuclear extract from brain tissue was assayed for Nrf2 transcriptional factor activity. RT-qPCR was performed for Nfe2l2, Sod1, Hmox1, Nqo1, and Mgst1; and Western blotting for determination of protein expression of Nrf2, p62, Pp62, Keap, HO1, and NQO1. Fluoro-jade C staining was also used to examine neuronal damage. Results: ZLHXTY capsule treatment following ICH demonstrated a protective effect against oxidative brain injury. Neurological scoring showed improvement in behavioral outcomes. ELISA-based identification demonstrated a significant decline in the expression of serum inflammatory markers. Hydrogen peroxide content in serum was found to be reduced. The total antioxidant capacity was also reduced in serum, but the ZLHXTY extract showed a concentration-dependent increase in T-AOC speculating at its intrinsic antioxidant potential. Nrf2 transcriptional factor activity, mRNA and protein expression analyses revealed normalization of Nrf2 and its downstream targets, which were previously elevated as a result of oxidative stress induced by ICH. Neuronal damage was also reduced markedly after ZLHXTY treatment as revealed by Fluoro-jade C staining. Conclusion: ZLHXTY capsules possess an intrinsic antioxidant potential that can modulate the ICH-induced redox imbalance in the brain as revealed by the normalization of Nrf2 and its downstream antioxidant targets.

Clinical and paraclinical predictors of early neurological deterioration and poor outcome in spontaneous intracerebral hemorrhage

Background

Spontaneous intracerebral hemorrhage (sICH) is the second most common form of stroke. It is a major cause of morbidity and mortality. Several clinical and radiological parameters are related to its poor outcome. The aim of this study is to elucidate the clinical, laboratory, and radiological factors associated with early neurological deterioration and poor outcome in patients with ICH.

Results

seventy patients diagnosed with sICH were evaluated within the first 72 h from the onset of symptoms by Clinical, radiological, and laboratory parameters. Patients were assessed for early neurological deterioration (END) during the hospital stay (up to 7 days from admission) using Glasgow coma scale (GSC), and the National Institutes of Health Stroke Scale (NIHSS), and within 3 months from stroke onset using modified Rankin scale (mRS). ICH score and Functional Outcome in Patients with Primary Intracerebral Hemorrhage (FUNC) Score were calculated for prognostication. 27.1% and 71.42% of patients had END and showed unfavorable outcome, respectively. Clinical indices, as NIHSS > 7 on admission and age > 51 years, radiological characteristics, as large hematoma size, leukoaraiosis, and mass effect detected on CT scan, as well as serum biomarkers; serum urea level > 50 mg/dL, high neutrophil:lymphocyte ratio on admission, high ALT and AST, as well as low total, LDL, and HDL cholesterol levels, all were significantly associated with poor outcome in the patients. Stepwise multivariate logistic regression analysis found the presence of aspiration to be an independent predictor of END, and the scores of NIHSS > 7 on admission, age > 51 years, and urea level > 50 mg/dL were independent predictors of poor outcome.

Conclusions

There are several predictors for END as well as poor outcome in ICH. Some are clinical, others are radiological and laboratory. Aspiration was an independent predictor of END during hospital stay (3-7 days) in patients with ICH, while older age, high NIHSS and urea level on admission were independent predictors of poor outcome.

Treatment of Intraventricular Hemorrhage with External Ventricular Drainage and Fibrinolysis: A Comprehensive Systematic Review and Meta-Analysis of Complications and Outcome

BACKGROUND

External ventricular drainage (EVD) is a key factor in the treatment of intraventricular hemorrhage (IVH) but associated with risks and complications. Intraventricular fibrinolysis (IVF) has been proposed to improve clinical outcome and reduce complications of EVD treatment. The following review and metaanalysis provides a comprehensive evaluation of IVH treatment with external ventricular drainage (EVD) and intraventricular fibrinolysis (IVF) with regards to complications and clinical outcomes.

METHODS

The PRISMA guidelines were followed preparing this review. Studies included in the meta-analysis were compared using forest plots and the related odds ratios.

RESULTS

After a literature search, 980 articles were identified and 65 and underwent full-text review. Forty-two articles were included in the review and meta-analysis. We found that bolted and antibiotic-coated catheters were superior to tunnelled/uncoated catheters (P < 0.001) and antibiotic- vs. silver-impregnated catheters (P < 0.001]) in preventing infection. Shunt dependency was related to the volume of blood in the ventricles but unaffected by IVF (P = 0.98). IVF promoted hematoma clearance, decreased mortality (22.4% vs. 40.9% with IVF vs. no IVF, respectively, P < 0.00001), improved good functional outcomes (47.2% [IVF] vs. 38.3% [no IVF], P = 0.03), and reduced the rate of catheter occlusion from 37.3% without IVF to 10.6% with IVF (P = 0.0003).

CONCLUSIONS

We present evidence and best practice recommendations for the treatment of IVH with EVD and intraventricular fibrinolysis. Our analysis further provides a comprehensive quantitative reference of the most relevant clinical endpoints for future studies on novel IVH technologies and treatments.

Risk Factors and Prognostic Implications of New-Onset Paroxysmal Atrial Fibrillation in Patients Hospitalized with Intracerebral Hemorrhage

Objective

We aimed to assess the prevalence and risk factors of new-onset paroxysmal atrial fibrillation (PAF) in patients hospitalized with ICH and determine whether the new-onset PAF had influenced functional outcomes.

Methods

We analyzed a database of all consecutive patients with ICH from October 2013 to May 2022. Univariate and multivariable regression analyses were performed to identify risk factors for new-onset PAF in patients with ICH. Multivariate models were also constructed to assess whether the new-onset PAF was an independent predictor of poor functional outcome, as measured using the modified Rankin scale.

Results

This study included 650 patients with ICH, among whom 24 patients had new-onset PAF. In the multivariable model, older age (OR per 10-y increase, 2.26 [95% CI, 1.52-3.35]; P<0.001), hematoma volume (OR per 10-mL increase, 1.80 [95% CI, 1.26-2.57]; P=0.001), and heart failure (OR, 21.77 [95% CI, 5.52-85.91]; P<0.001) were independent risk factors for new-onset PAF. In a sensitivity analysis restricted to 428 patients with N-terminal pro-B-type natriuretic peptide (NT-proBNP), older age, larger hematoma volume, heart failure, and increased NT-proBNP were associated with new-onset PAF. After adjusting for baseline variables, new-onset PAF was an independent predictor of poor functional outcome (OR, 10.35 [95% CI, 1.08-98.80]; P=0.042).

Conclusion

Older age, larger hematoma volume, and heart failure were independent risk factors for new-onset PAF after ICH. Increased NT-proBNP is correlated with higher risks for new-onset PAF when their information is available at admission. Furthermore, new-onset PAF is a significant predictor of poor functional outcome.

Mesenchymal stem cells transplantation combined with IronQ attenuates ICH-induced inflammation response via Mincle/syk signaling pathway

BACKGROUND

Intracerebral hemorrhage (ICH) is a severe brain-injured disease accompanied by cerebral edema, inflammation, and subsequent neurological deficits. Mesenchymal stem cells (MSCs) transplantation has been used as a neuroprotective therapy in nervous system diseases because of its anti-inflammatory effect. Nevertheless, the biological characteristics of transplanted MSCs, including the survival rate, viability, and effectiveness, are restricted because of the severe inflammatory response after ICH. Therefore, improving the survival and viability of MSCs will provide a hopeful therapeutic efficacy for ICH. Notably, the biomedical applications of coordination chemistry-mediated metal-quercetin complex have been verified positively and studied extensively, including growth-promoting and imaging probes. Previous studies have shown that the iron-quercetin complex (IronQ) possesses extraordinary dual capabilities with a stimulating agent for cell growth and an imaging probe by magnetic resonance imaging (MRI). Therefore, we hypothesized that IronQ could improve the survival and viability of MSCs, displaying the anti-inflammation function in the treatment of ICH while also labeling MSCs for their tracking by MRI. This study aimed to explore the effects of MSCs with IronQ in regulating inflammation and further clarify their potential mechanisms.

METHODS

C57BL/6 male mice were utilized in this research. A collagenase I-induced ICH mice model was established and randomly separated into the model group (Model), quercetin gavage group (Quercetin), MSCs transplantation group (MSCs), and MSCs transplantation combined with IronQ group (MSCs + IronQ) after 24 h. Then, the neurological deficits score, brain water content (BWC), and protein expression, such as TNF-α, IL-6, NeuN, MBP, as well as GFAP, were investigated. We further measured the protein expression of Mincle and its downstream targets. Furthermore, the lipopolysaccharide (LPS)-induced BV2 cells were utilized to investigate the neuroprotection of conditioned medium of MSCs co-cultured with IronQ in vitro.

RESULTS

We found that the combined treatment of MSCs with IronQ improved the inflammation-induced neurological deficits and BWC in vivo by inhibiting the Mincle/syk signaling pathway. Conditioned medium derived from MSCs co-cultured with IronQ decreased inflammation, Mincle, and its downstream targets in the LPS-induced BV2 cell line.

CONCLUSIONS

These data suggested that the combined treatment exerts a collaborative effect in alleviating ICH-induced inflammatory response through the downregulation of the Mincle/syk signaling pathway following ICH, further improving the neurologic deficits and brain edema.

Increased serum fibroblast growth factor 21 levels are associated with adverse clinical outcomes after intracerebral hemorrhage

Introduction

Intracerebral hemorrhage (ICH) is the most prevalent cause of death. We sought to explore whether serum Fibroblast growth factor 21 (FGF21) is of substantial benefit in predicting poor prognosis in ICH patient.

Methods

A prospective, multicenter cohort analysis of serum FGF21 levels in 418 ICH patients was carried out. At three months following ICH start, the primary endpoint was death or major disability, whereas the secondary endpoint was death. We investigated the association between serum FGF21 and clinical outcomes. We added FGF21 to the existing rating scale to assess whether it enhanced the prediction ability of the original model. Effectiveness was determined by calculating the C-statistic, net reclassification index (NRI), absolute integrated discrimination improvement (IDI) index.

Results

Among 418 enrolled patients, 217 (51.9%) of the all subjects had death or significant disability. Compared with patients in the lowest quartile group, those in the first quartile group had higher risk of the primary outcome (Odds ratio, 2.73 [95%CI,1.42-5.26, p < 0.05]) and second outcome (Hazard ratio, 4.28 [95%CI,1.61-11.42, p < 0.001]). The integration of FGF21 into many current ICH scales improved the discrimination and calibration quality for the integrated discrimination index's prediction of main and secondary findings (all p < 0.05).

Conclusion

Elevated serum FGF21 is associated with increased risks of adverse clinical outcomes at 3 months in ICH patients, suggesting FGF21 may be a valuable prognostic factor.

The Potential of NLRP3 Inflammasome as a Therapeutic Target in Neurological Diseases

NLRP3 (NLRP3: NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome is the best-described inflammasome that plays a crucial role in the innate immune system and a wide range of diseases. The intimate association of NLRP3 with neurological disorders, including neurodegenerative diseases and strokes, further emphasizes its prominence as a clinical target for pharmacological intervention. However, after decades of exploration, the mechanism of NLRP3 activation remains indefinite. This review highlights recent advances and gaps in our insights into the regulation of NLRP3 inflammasome. Furthermore, we present several emerging pharmacological approaches of clinical translational potential targeting the NLRP3 inflammasome in neurological diseases. More importantly, despite small-molecule inhibitors of the NLRP3 inflammasome, we have focused explicitly on Chinese herbal medicine and botanical ingredients, which may be splendid therapeutics by inhibiting NLRP3 inflammasome for central nervous system disorders. We expect that we can contribute new perspectives to the treatment of neurological diseases.

Circulating lipocalin-2 as a novel biomarker for early neurological deterioration and unfavorable prognosis after acute ischemic stroke

INTRODUCTION

Lipocalin-2 (LCN2) is an acute-phase protein that could mediate neuroinflammation after brain injury. We aimed to evaluate if LCN2 level was associated with early neurological deterioration (END) in acute ischemic stroke patients, thus hindering clinical recovery.

METHODS

We conducted a prospective study of acute ischemic stroke patients between June 2021 and February 2022. Serum LCN2 concentration was measured after admission using an enzyme-linked immunosorbent assay. Outcomes included END and 90-day poor functional outcome (modified Rankin Scale 3-6). The National Institutes of Health Stroke Scale increment ≥4 points within 72 h after admission was defined as END.

RESULTS

A total of 253 acute ischemic stroke patients (mean age, 65.2 ± 13.4 years; 64.0% male) were recruited. In the multivariate adjustment, increased serum LCN2 levels (per 1-SD increase of LCN2) were associated with a higher risk of END (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.20-2.25; p = .002) and 90-day poor outcome (OR, 1.73; 95% CI, 1.22-2.45; p = .002). Restricted cubic splines found a linear relationship between LCN2 level and 90-day unfavorable outcome (END, p = .001 for linearity; 90-day poor outcome, p = .013 for linearity). Subgroup analysis further confirmed the significant association of LCN2 with clinical outcomes.

CONCLUSIONS

This study demonstrated that higher circulating LCN2 level was associated with an increased risk of early clinical worsening and 90-day unfavorable outcomes in ischemic stroke patients.

TGF-β1 ameliorates BBB injury and improves long-term outcomes in mice after ICH

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke characterized by high mortality and morbidity rates with no effective treatment. TGF-β/ALK-5 signaling is reported to participated in the regulation of blood-brain barrier (BBB) integrity in the inflammation pain model, the effects of transforming growth factor (TGF)-β1 and the potential mechanisms on BBB after ICH have not been fully elucidated. Herein, we have demonstrated that peripheral administration of TGF-β1 reduces brain edema and ameliorated BBB injury after ICH. Consistent with previous results, TGF-β1 is shown to promote activation of anti-inflammatory microglia and reduce the inflammatory response after ICH. Furthermore, TGF-β1 administration improves long-term outcomes after ICH. Our data suggest that TGF-β1 may be a promising therapeutic agent for ICH.

Safety and technical efficacy of early minimally invasive endoscopy-guided surgery for intracerebral haemorrhage: the Dutch Intracerebral haemorrhage Surgery Trial pilot study

BACKGROUND

Previous randomised controlled trials could not demonstrate that surgical evacuation of intracerebral haemorrhage (ICH) improves functional outcome. Increasing evidence suggests that minimally invasive surgery may be beneficial, in particular when performed early after symptom onset. The aim of this study was to investigate safety and technical efficacy of early minimally invasive endoscopy-guided surgery in patients with spontaneous supratentorial ICH.

METHODS

The Dutch Intracerebral Haemorrhage Surgery Trial pilot study was a prospective intervention study with blinded outcome assessment in three neurosurgical centres in the Netherlands. We included adult patients with spontaneous supratentorial ICH ≥10mL and National Institute of Health Stroke Scale (NIHSS) score ≥2 for minimally invasive endoscopy-guided surgery within 8 h after symptom onset in addition to medical management. Primary safety outcome was death or increase in NIHSS ≥4 points at 24 h. Secondary safety outcomes were procedure-related serious adverse events (SAEs) within 7 days and death within 30 days. Primary technical efficacy outcome was ICH volume reduction (%) at 24 h.

RESULTS

We included 40 patients (median age 61 years; IQR 51-67; 28 men). Median baseline NIHSS was 19.5 (IQR 13.3-22.0) and median ICH volume 47.7mL (IQR 29.4-72.0). Six patients had a primary safety outcome, of whom two already deteriorated before surgery and one died within 24 h. Sixteen other SAEs were reported within 7 days in 11 patients (of whom two patients that already had a primary safety outcome), none device related. In total, four (10%) patients died within 30 days. Median ICH volume reduction at 24 h was 78% (IQR 50-89) and median postoperative ICH volume 10.5mL (IQR 5.1-23.8).

CONCLUSIONS

Minimally invasive endoscopy-guided surgery within 8 h after symptom onset for supratentorial ICH appears to be safe and can effectively reduce ICH volume. Randomised controlled trials are needed to determine whether this intervention also improves functional outcome.

TRIAL REGISTRATION

Clinicaltrials.gov : NCT03608423, August 1st, 2018.

Research advances in imaging markers for predicting hematoma expansion in intracerebral hemorrhage: a narrative review

Introduction

Stroke is a major global health concern and is ranked as the second leading cause of death worldwide, with the third highest incidence of disability. Intracerebral hemorrhage (ICH) is a devastating form of stroke that is responsible for a significant proportion of stroke-related morbidity and mortality worldwide. Hematoma expansion (HE), which occurs in up to one-third of ICH patients, is a strong predictor of poor prognosis and can be potentially preventable if high-risk patients are identified early. In this review, we provide a comprehensive summary of previous research in this area and highlight the potential use of imaging markers for future research studies.

Recent advances

Imaging markers have been developed in recent years to aid in the early detection of HE and guide clinical decision-making. These markers have been found to be effective in predicting HE in ICH patients and include specific manifestations on Computed Tomography (CT) and CT Angiography (CTA), such as the spot sign, leakage sign, spot-tail sign, island sign, satellite sign, iodine sign, blend sign, swirl sign, black hole sign, and hypodensities. The use of imaging markers holds great promise for improving the management and outcomes of ICH patients.

Conclusion

The management of ICH presents a significant challenge, and identifying high-risk patients for HE is crucial to improving outcomes. The use of imaging markers for HE prediction can aid in the rapid identification of such patients and may serve as potential targets for anti-HE therapies in the acute phase of ICH. Therefore, further research is needed to establish the reliability and validity of these markers in identifying high-risk patients and guiding appropriate treatment decisions.

Enhanced Proliferation of Visualizable Mesenchymal Stem Cell-Platelet Hybrid Cell for Versatile Intracerebral Hemorrhage Treatment

The intrinsic features and functions of platelets and mesenchymal stem cells (MSCs) indicate their great potential in the treatment of intracerebral hemorrhage (ICH). However, neither of them can completely overcome ICH because of the stealth process and the complex pathology of ICH. Here, we fabricate hybrid cells for versatile and highly efficient ICH therapy by fusing MSCs with platelets and loading with lysophosphatidic acid-modified PbS quantum dots (LPA-QDs). The obtained LPA-QDs@FCs (FCs = fusion cells) not only inherit the capabilities of both platelets and MSCs but also exhibit clearly enhanced proliferation activated by LPA. After systemic administration, many proliferating LPA-QDs@FCs rapidly accumulate in ICH areas for responding to the vascular damage and inflammation and then efficiently prevent both the primary and secondary injuries of ICH but with no obvious side effects. Moreover, the treatment process can be tracked by near-infrared II fluorescence imaging with highly spatiotemporal resolution, providing a promising solution for ICH therapy.

The Clinical Value of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio for Predicting Hematoma Expansion and Poor Outcomes in Patients with Acute Intracerebral Hemorrhage

There is little knowledge of the effect of inflammatory markers on the prognoses of hematoma expansion (HE) in patients with intracranial hemorrhage (ICH). We evaluated the impact of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) on HE and worse outcomes after acute ICH. This study included 520 consecutive patients with ICH from the registry database enrolled over 80 months. Patients' whole blood samples were collected upon arrival in the emergency department. Brain computed tomography scans were performed during hospitalization and repeated at 24 h and 72 h. The primary outcome measure was HE, defined as relative growth >33% or absolute growth <6 mL. A total of 520 patients were enrolled in this study. Multivariate analysis showed that NLR and PLR were associated with HE (NLR: odds ratio [OR], [95% CI] = 1.19 [1.12-1.27], p < 0.001; PLR: OR, [95% CI] = 1.01 [1.00-1.02], p = 0.04). Receiver operating characteristic curve analysis revealed that NLR and PLR could predict HE (AUC of NLR: 0.84, 95% CI [0.80-0.88], p < 0.001; AUC of PLR: 0.75 95% CI [0.70-0.80], p < 0.001). The cut-off value of NLR for predicting HE was 5.63, and that of PLR was 23.4. Higher NLR and PLR values increase HE risk in patients with ICH. NLR and PLR were reliable for predicting HE after ICH.

Spatiotemporal Cofilin Signaling, Microglial Activation, Neuroinflammation, and Cognitive Impairment Following Hemorrhagic Brain Injury

Intracerebral hemorrhage (ICH) is a significant health concern associated with high mortality. Cofilin plays a crucial role in stress conditions, but its signaling following ICH in a longitudinal study is yet to be ascertained. In the present study, we examined the cofilin expression in human ICH autopsy brains. Then, the spatiotemporal cofilin signaling, microglia activation, and neurobehavioral outcomes were investigated in a mouse model of ICH. Human autopsy brain sections from ICH patients showed increased intracellular cofilin localization within microglia in the perihematomal area, possibly associated with microglial activation and morphological changes. Various cohorts of mice were subjected to intrastriatal collagenase injection and sacrificed at time points of 1, 3, 7, 14, 21, and 28 days. Mice suffered from severe neurobehavioral deficits after ICH, lasting for 7 days, followed by a gradual improvement. Mice suffered post-stroke cognitive impairment (PSCI) both acutely and in the chronic phase. Hematoma volume increased from day 1 to 3, whereas ventricle size increased from day 21 to 28. Cofilin protein expression increased in the ipsilateral striatum on days 1 and 3 and then decreased from days 7 to 28. An increase in activated microglia was observed around the hematoma on days 1 to 7, followed by a gradual reduction up to day 28. Around the hematoma, activated microglia showed morphological changes from ramified to amoeboid. mRNA levels of inflammatory [tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and interleukin-6 (IL-6) and anti-inflammatory markers [interleukin-10 (IL-10), transforming growth factor-β TGF-β, and arginase I (Arg1)] increased during the acute phase and decreased in the chronic phase. Blood cofilin levels increased on day 3 and matched the increase in chemokine levels. slingshot protein phosphatase 1 (SSH1) protein, which activates cofilin, was increased from day 1 to 7. These results suggest that microglial activation might be the sequel of cofilin overactivation following ICH, leading to widespread neuroinflammation and consequent PSCI.

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.

Role of lipocalin 2 in stroke

Stroke is the second leading cause of death worldwide; however, the treatment choices available to neurologists are limited in clinical practice. Lipocalin 2 (LCN2) is a secreted protein, belonging to the lipocalin superfamily, with multiple biological functions in mediating innate immune response, inflammatory response, iron-homeostasis, cell migration and differentiation, energy metabolism, and other processes in the body. LCN2 is expressed at low levels in the brain under normal physiological conditions, but its expression is significantly up-regulated in multiple acute stimulations and chronic pathologies. An up-regulation of LCN2 has been found in the blood/cerebrospinal fluid of patients with ischemic/hemorrhagic stroke, and could serve as a potential biomarker for the prediction of the severity of acute stroke. LCN2 activates reactive astrocytes and microglia, promotes neutrophil infiltration, amplifies post-stroke inflammation, promotes blood-brain barrier disruption, white matter injury, and neuronal death. Moreover, LCN2 is involved in brain injury induced by thrombin and erythrocyte lysates, as well as microvascular thrombosis after hemorrhage. In this paper, we review the role of LCN2 in the pathological processes of ischemic stroke; intracerebral hemorrhage; subarachnoid hemorrhage; and stroke-related brain diseases, such as vascular dementia and post-stroke depression, and their underlying mechanisms. We hope that this review will help elucidate the value of LCN2 as a therapeutic target in stroke.

Emergency management of intracerebral hemorrhage

Acute intracerebral hemorrhage is a medical emergency with high mortality and morbidity. Neuroimaging has a fundamental role in the etiological diagnosis, patients monitoring and in the risk stratification of hematoma expansion and poor outcome. The cornerstones of medical treatment in the acute phase are blood pressure lowering and coagulopathy reversal. Prevention of hematoma expansion is the main goal of these therapies and their efficacy is strongly time-dependent with a narrow time window. This review provides an update on the etiological diagnostic workup, acute treatment and prognosis of intracerebral hemorrhage.

Quantitative Susceptibility Mapping and Amide Proton Transfer-Chemical Exchange Saturation Transfer for the Evaluation of Intracerebral Hemorrhage Model

This study aimed to evaluate an intracerebral hemorrhage (ICH) model using quantitative susceptibility mapping (QSM) and chemical exchange saturation transfer (CEST) with preclinical 7T-magnetic resonance imaging (MRI) and determine the potential of amide proton transfer-CEST (APT-CEST) for use as a biomarker for the early detection of ICH. Six Wistar male rats underwent MRI, and another six underwent histopathological examinations on postoperative days 0, 3, and 7. The ICH model was created by injecting bacterial collagenase into the right hemisphere of the brain. QSM and APT-CEST MRI were performed using horizontal 7T-MRI. Histological studies were performed to observe ICH and detect iron deposition at the ICH site. T2-weighted images (T2WI) revealed signal changes associated with hemoglobin degeneration in red blood cells, indicating acute-phase hemorrhage on day 0, late-subacute-phase hemorrhage on day 3, and chronic-phase hemorrhage on day 7. The susceptibility alterations in each phase were detected using QSM. QSM and Berlin blue staining revealed hemosiderin deposition in the chronic phase. APT-CEST revealed high magnetization transfer ratios in the acute phase. Abundant mobile proteins and peptides were observed in early ICH, which were subsequently diluted. APT-CEST imaging may be a reliable noninvasive biomarker for the early diagnosis of ICH.

Aquaporin-4 in glymphatic system, and its implication for central nervous system disorders

The clearance function is essential for maintaining brain tissue homeostasis, and the glymphatic system is the main pathway for removing brain interstitial solutes. Aquaporin-4 (AQP4) is the most abundantly expressed aquaporin in the central nervous system (CNS) and is an integral component of the glymphatic system. In recent years, many studies have shown that AQP4 affects the morbidity and recovery process of CNS disorders through the glymphatic system, and AQP4 shows notable variability in CNS disorders and is part of the pathogenesis of these diseases. Therefore, there has been considerable interest in AQP4 as a potential and promising target for regulating and improving neurological impairment. This review aims to summarize the pathophysiological role that AQP4 plays in several CNS disorders by affecting the clearance function of the glymphatic system. The findings can contribute to a better understanding of the self-regulatory functions in CNS disorders that AQP4 were involved in and provide new therapeutic alternatives for incurable debilitating neurodegenerative disorders of CNS in the future.

Iron-Induced Hydrocephalus: the Role of Choroid Plexus Stromal Macrophages

Evidence indicates that erythrocyte-derived iron and inflammation both play a role in intraventricular hemorrhage-induced brain injury including hydrocephalus. Many immune-associated cells, primarily stromal macrophages, reside at the choroid plexus where they are involved in inflammatory responses and antigen presentation. However, whether intraventricular iron impacts those stromal cells is unknown. The aim of this study was to evaluate the relationship between choroid plexus stromal macrophages and iron-induced hydrocephalus in rats and the impact of minocycline and clodronate liposomes on those changes. Aged (18-month-old) and young (3-month-old) male Fischer 344 rats were used to study choroid plexus stromal macrophages. Rats underwent intraventricular iron injection to induce hydrocephalus and treated with either minocycline, a microglia/macrophage inhibitor, or clodronate liposomes, a macrophage depleting agent. Ventricular volume was measured using magnetic resonance imaging, and stromal macrophages were quantified by immunofluorescence staining. We found that stromal macrophages accounted for about 10% of the total choroid plexus cells with more in aged rats. In both aged and young rats, intraventricular iron injection resulted in hydrocephalus and increased stromal macrophage number. Minocycline or clodronate liposomes ameliorated iron-induced hydrocephalus and the increase in stromal macrophages. In conclusion, stromal macrophages account for ~10% of all choroid plexus cells, with more in aged rats. Treatments targeting macrophages (minocycline and clodronate liposomes) are associated with reduced iron-induced hydrocephalus.

An Ambiguous Role for Fever in Worsening Outcome After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and leaves most survivors with impairments. Fever, a rise in the thermoregulatory set point, complicates ICH. This review summarizes ICH fever studies and employs meta-analytic techniques to explore the relationship between fever and ICH. We discuss methodological considerations for future studies and provide an overview of mechanisms by which fever, and its treatment, may impact ICH. We searched the PubMed database using the following terms: ((fever OR hyperthermia) AND (intracerebral hemorrhage OR intraparenchymal hemorrhage OR intracerebral haemorrhage OR intraparenchymal haemorrhage)). Our search returned 727 studies, of which 21 were included in our final analysis, consisting of 19 clinical, and two preclinical, studies. We conducted a meta-analysis on the clinical data to quantify how fever is related to mortality, functional outcomes, and intraventricular hemorrhage. Analysis of clinical studies suggested that fever causes an increased risk of mortality but does not appear to be associated with poor outcomes among survivors, making it difficult to ascertain the extent of harm caused by post-ICH fever or the benefits of its treatment. Perhaps these inconsistencies stem from variable fever definitions, and temperature measurement and fever treatment protocols. Additionally, the lack of mechanistic data in clinical studies coupled with preclinical studies showing no harmful effects of moderate bouts of hyperthermia raise concerns about the direct contribution of hyperthermia and fever in post ICH outcome. Overall, the significance of temperature increases after ICH is unclear, making this an important area for future research.

Inflammatory Markers as Predictors of Shunt Dependency and Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage

The mechanisms underlying post-hemorrhagic hydrocephalus (PHH) development following subarachnoid hemorrhage (SAH) are not fully understood, which complicates informed clinical decisions regarding the duration of external ventricular drain (EVD) treatment and prevents the prediction of shunt-dependency in the individual patient. The aim of this study was to identify potential inflammatory cerebrospinal fluid (CSF) biomarkers of PHH and, thus, shunt-dependency and functional outcome in patients with SAH. This study was a prospective observational study designed to evaluate inflammatory markers in ventricular CSF. In total, 31 Patients with SAH who required an EVD between June 2019 and September 2021 at the Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark, were included. CSF samples were collected twice from each patient and analyzed for 92 inflammatory markers via proximity extension assay (PEA), and the prognostic ability of the markers was investigated. In total, 12 patients developed PHH, while 19 were weaned from their EVD. Their 6-month functional outcome was determined with the modified Rankin Scale. Of the 92 analyzed inflammatory biomarkers, 79 were identified in the samples. Seven markers (SCF, OPG, LAP TGFβ1, Flt3L, FGF19, CST5, and CSF1) were found to be predictors of shunt dependency, and four markers (TNFα, CXCL5, CCL20, and IL8) were found to be predictors of functional outcome. In this study, we identified promising inflammatory biomarkers that are able to predict (i) the functional outcome in patients with SAH and (ii) the development of PHH and, thus, the shunt dependency of the individual patients. These inflammatory markers may have the potential to be employed as predictive biomarkers of shunt dependency and functional outcome following SAH and could, as such, be applied in the clinic.

Identification of CCL20 as a Key Biomarker of Inflammatory Responses in the Pathogenesis of Intracerebral Hemorrhage

Inflammatory responses after intracerebral hemorrhage (ICH) contribute to severe secondary brain injury, leading to poor clinical outcomes. However, the responsible genes for effective anti-inflammation treatment in ICH remain poorly elucidated. The differentially expressed genes (DEGs) of human ICH were explored by online GEO2R. Go and KEGG were used to explore the biological function of DEGs. Protein-protein interactions (PPI) were built in the String database. Critical modules of PPI were identified by a molecular complex detection algorithm (MCODE). Cytohubba was used to determine the hub genes. The mRNA-miRNA interaction network was built in the miRWalk database. The rat ICH model was applied to validate the key genes. A total of 776 DEGs were identified in ICH. Go and KEGG analyses indicated that DEGs were mainly involved in neutrophil activation and the TNF signaling pathway. GSEA analysis presented that DEGs were significantly enriched in TNF signaling and inflammatory response. PPI network was constructed in the 48 differentially expressed inflammatory response-related genes. The critical module of the PPI network was constructed by 7 MCODE genes and functioned as the inflammatory response. The top 10 hub genes with the highest degrees were identified in the inflammatory response after ICH. CCL20 was confirmed as a key gene and mainly expressed in neurons in the rat ICH model. The regulatory network between CCL20 and miR-766 was built, and the miR-766 decrease was confirmed in a human ICH dataset. CCL20 is a key biomarker of inflammatory response after intracerebral hemorrhage, providing a potential target for inflammatory intervention in ICH.

Microglial IL-1RA ameliorates brain injury after ischemic stroke by inhibiting astrocytic CXCL1-mediated neutrophil recruitment and microvessel occlusion

Acute ischemic stroke (AIS), one of the leading causes of mortality worldwide, is characterized by a rapid inflammatory cascade resulting in exacerbation of ischemic brain injury. Microglia are the first immune responders. However, the role of postischemic microglial activity in ischemic brain injury remains far from being fully understood. Here, using the transgenic mouse line CX₃ CR1^creER :R26^iDTR to genetically ablate microglia, we showed that microglial deletion exaggerated ischemic brain injury. Associated with this worse outcome, there were increased neutrophil recruitment, microvessel blockade and blood flow stagnation in the acute phase, accompanied by transcriptional upregulation of chemokine (C-X-C motif) ligand 1 (CXCL1). Our study showed that microglial interleukin-1 receptor antagonist (IL-1RA) suppressed astrocytic CXCL1 expression induced by oxygen and glucose deprivation and inhibited neutrophil migration. Furthermore, neutralizing antibody therapy against CXCL1 or the administration of recombinant IL-1RA protein reduced brain infarct volume and improved motor coordination performance of mice after ischemic stroke. Our study suggests that microglia protect against acute ischemic brain injury by secreting IL-1RA to inhibit astrocytic CXCL1 expression, which reduces neutrophil recruitment and neutrophil-derived microvessel occlusion.

Intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a dramatic condition caused by the rupture of a cerebral vessel and the entry of blood into the brain parenchyma. ICH is a major contributor to stroke-related mortality and dependency: only half of patients survive for 1 year after ICH, and patients who survive have sequelae that affect their quality of life. The incidence of ICH has increased in the past few decades with shifts in the underlying vessel disease over time as vascular prevention has improved and use of antithrombotic agents has increased. The pathophysiology of ICH is complex and encompasses mechanical mass effect, haematoma expansion and secondary injury. Identifying the causes of ICH and predicting the vital and functional outcome of patients and their long-term vascular risk have improved in the past decade; however, no specific treatment is available for ICH. ICH remains a medical emergency, with prevention of haematoma expansion as the key therapeutic target. After discharge, secondary prevention and management of vascular risk factors in patients remains challenging and is based on an individual benefit-risk balance evaluation.

Chemical synthesis of oligosaccharides and their application in new drug research

Oligosaccharides are the ubiquitous molecules of life. In order to translate human bioglycosylation into clinical applications, homogeneous samples of oligosaccharides and glycoconjugates can be obtained by chemical, enzymatic or other biological methods for systematic studies. However, the structural complexity and diversity of glycans and their conjugates present a major challenge for the synthesis of such molecules. This review summarizes the chemical synthesis methods of oligosaccharides, the application of oligosaccharides in the field of medicinal chemistry according to their related biological activities, and shows the great prospect of oligosaccharides in the field of pharmaceutical chemistry.

Intracerebral Hemorrhage Models and Behavioral Tests in Rodents

Intracerebral hemorrhage (ICH) is one of the common types of stroke, which can cause neurological dysfunction. In preclinical ICH studies, researchers often established rodent models by donor/autologous whole blood or a collagenase injection. White matter injury (WMI) can result from primary and secondary injuries after ICH. WMI can lead to short- and long-term neurological impairment, and functional recovery can assess the effect of drug therapy after ICH. Therefore, researchers have devised various behavioral tests to assess dysfunction. This review compares the two ICH modeling methods in rodents and summarizes the pathological mechanisms underlying dysfunction after ICH. We also summarize the functions and characteristics of various behavioral methods, including sensation, motion, emotion, and cognition, to assist researchers in selecting the appropriate tests for preclinical ICH research.

Neurod1 mediates the reprogramming of NG2 glial into neurons in vitro

Neuronal defect and loss are the main pathological processes of many central nervous system diseases. Cellular reprogramming is a promising method to supplement lost neurons. However, study on cellular reprogramming is still limited and its mechanism remains unclear. Herein, the effect of Neurod1 expression on differentiation of NG2 glia into neurons was investigated. In this study, we successfully isolated NG2 glial cells from mice prior to identification with immunofluorescence. Afterwards, AAV-Neurod1 virus was used to construct Neurod1 overexpression vectors in NG2 glia. Later, we detected neuronal markers expression with immunofluorescence and real time quantitative polymerase-chain reaction (qRT-PCR). Besides, expression of MAPK-signaling-pathway-related proteins were detected by western blotting technique. Through immunofluorescence and qRT-PCR techniques, we observed that Neurod1 overexpression contributed to NG2 cells differentiated into neurons. Further experiments also showed that Neurod1 overexpression induced the activation of MAPK pathway, but PD98059 (a selective inhibitor of MAPK pathway) partly inhibited the neuronal differentiation induced by Neurod1 overexpression. These findings suggest that Neurod1 could promote NG2 glia cells differentiating into neurons, wherein the mechanism under the differentiation is related to activation of MAPK pathway.

Combination of Hematoma Volume and Perihematoma Radiomics Analysis on Baseline CT Scan Predicts the Growth of Perihematomal Edema

PURPOSE

The aim is to explore the potential value of CT-based radiomics in predicting perihematomal edema (PHE) volumes after acute intracerebral hemorrhage (ICH) from admission to 24 h.

METHODS

A total of 231 patients newly diagnosed with acute ICH at two institutes were analyzed retrospectively. The patients were randomly divided into training (N = 117) and internal validation cohort (N = 45) from institute 1 with a ratio of 7:3. According to radiomics features extracted from baseline CT, the radiomics signatures were constructed. Multiple logistic regression analysis was used for clinical radiological factors and then the nomogram model was generated to predict the extent of PHE according to the optimal radiomics signature and the clinical radiological factors. The receiver operating characteristic (ROC) curve was used to evaluate the discrimination performance. The calibration curve and Hosmer-Lemeshow test were used to evaluate the consistency between the predicted and actual probability. The support vector regression (SVR) model was constructed to predict the overall value of follow-up PHE. The performance of the models was evaluated on the internal and independent validation cohorts.

RESULTS

The perihematoma 5 mm radiomics signature (AUC: 0.875) showed good ability to discriminate the small relative PHE(rPHE) from large rPHE volumes, comparing to intrahematoma radiomics signature (AUC: 0.711) or perihematoma 10 mm radiomics signature (AUC: 0.692) on the training cohort. The AUC of the combined nomogram model was 0.922 for the training cohort, 0.945 and 0.902 for the internal and independent validation cohorts, respectively. The calibration curves and Hosmer-Lemeshow test of the nomogram model suggested that the predictive performance and actual outcome were in favorable agreement. The SVR model also predicted the overall value of follow-up rPHE (root mean squared error, 0.60 and 0.45; Pearson correlation coefficient, 0.73 and 0.68; P < 0.001).

CONCLUSION

Among patients with acute ICH, the established nomogram and SVR model with favorable performance can offer a noninvasive tool for the prediction of PHE after ICH.

The Yin and Yang Effect of the Apelinergic System in Oxidative Stress

Apelin is an endogenous ligand for the G protein-coupled receptor APJ and has multiple biological activities in human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. This article reviews the crucial role of apelin in regulating oxidative stress-related processes by promoting prooxidant or antioxidant mechanisms. Following the binding of APJ to different active apelin isoforms and the interaction with several G proteins according to cell types, the apelin/APJ system is able to modulate different intracellular signaling pathways and biological functions, such as vascular tone, platelet aggregation and leukocytes adhesion, myocardial activity, ischemia/reperfusion injury, insulin resistance, inflammation, and cell proliferation and invasion. As a consequence of these multifaceted properties, the role of the apelinergic axis in the pathogenesis of degenerative and proliferative conditions (e.g., Alzheimer's and Parkinson's diseases, osteoporosis, and cancer) is currently investigated. In this view, the dual effect of the apelin/APJ system in the regulation of oxidative stress needs to be more extensively clarified, in order to identify new potential strategies and tools able to selectively modulate this axis according to the tissue-specific profile.

Therapeutic potential of puerarin against cerebral diseases: From bench to bedside

The incidence of cerebral diseases is rapidly increasing worldwide, and they have become an important challenge for modern medicine. Most of the available chemical drugs used in the treatment of cerebral diseases are highly toxic and single-targeted. Therefore, novel drugs from natural resources have attracted much attention for their potential to manage cerebral diseases. Puerarin is a natural isoflavone isolated from the roots of Pueraria species such as P. lobata (Willd) Ohwi, P. thomsonii, and P. mirifica. Several authors have reported the beneficial effects of puerarin in cerebral ischemic disease, intracerebral hemorrhage, vascular dementia, Alzheimer's disease, Parkinson's disease, depression, anxiety, and traumatic brain injury. This review summarizes the brain pharmacokinetics, brain drug delivery system, clinical use (in cerebral diseases), toxicity, and the adverse clinical reactions of puerarin. We have systematically presented the pharmacological actions and the molecular mechanisms of puerarin in various cerebral diseases to provide a direction for future research on the therapeutic use of puerarin in cerebral diseases.