Mannitol and Outcome in Intracerebral Hemorrhage

MCC950 as a promising candidate for blocking NLRP3 inflammasome activation: A review of preclinical research and future directions

The NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is a key component of the innate immune system that triggers inflammation and pyroptosis and contributes to the development of several diseases. Therefore, blocking the activation of the NLRP3 inflammasome has therapeutic potential for the treatment of these diseases. MCC950, a selective small molecule inhibitor, has emerged as a promising candidate for blocking NLRP3 inflammasome activation. Ongoing research is focused on elucidating the specific targets of MCC950 as well as assessfing its metabolism and safety profile. This review discusses the diseases that have been studied in relation to MCC950, with a focus on stroke, Alzheimer's disease, liver injury, atherosclerosis, diabetes mellitus, and sepsis, using bibliometric analysis. It then summarizes the potential pharmacological targets of MCC950 and discusses its toxicity. Furthermore, it traces the progression from preclinical to clinical research for the treatment of these diseases. Overall, this review provides a solid foundation for the clinical therapeutic potential of MCC950 and offers insights for future research and therapeutic approaches.

Can propensity score matching replace randomized controlled trials?

Randomized controlled trials (RCTs) have long been recognized as the gold standard for establishing causal relationships in clinical research. Despite that, various limitations of RCTs prevent its widespread implementation, ranging from the ethicality of withholding potentially-lifesaving treatment from a group to relatively poor external validity due to stringent inclusion criteria, amongst others. However, with the introduction of propensity score matching (PSM) as a retrospective statistical tool, new frontiers in establishing causation in clinical research were opened up. PSM predicts treatment effects using observational data from existing sources such as registries or electronic health records, to create a matched sample of participants who received or did not receive the intervention based on their propensity scores, which takes into account characteristics such as age, gender and comorbidities. Given its retrospective nature and its use of observational data from existing sources, PSM circumvents the aforementioned ethical issues faced by RCTs. Majority of RCTs exclude elderly, pregnant women and young children; thus, evidence of therapy efficacy is rarely proven by robust clinical research for this population. On the other hand, by matching study patient characteristics to that of the population of interest, including the elderly, pregnant women and young children, PSM allows for generalization of results to the wider population and hence greatly increases the external validity. Instead of replacing RCTs with PSM, the synergistic integration of PSM into RCTs stands to provide better research outcomes with both methods complementing each other. For example, in an RCT investigating the impact of mannitol on outcomes among participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial, the baseline characteristics of comorbidities and current medications between treatment and control arms were significantly different despite the randomization protocol. Therefore, PSM was incorporated in its analysis to create samples from the treatment and control arms that were matched in terms of these baseline characteristics, thus providing a fairer comparison for the impact of mannitol. This literature review reports the applications, advantages, and considerations of using PSM with RCTs, illustrating its utility in refining randomization, improving external validity, and accounting for non-compliance to protocol. Future research should consider integrating the use of PSM in RCTs to better generalize outcomes to target populations for clinical practice and thereby benefit a wider range of patients, while maintaining the robustness of randomization offered by RCTs.

Radiomics features from perihematomal edema for prediction of prognosis in the patients with basal ganglia hemorrhage

OBJECTIVE

We developed and validated a clinical-radiomics nomogram to predict the prognosis of basal ganglia hemorrhage patients.

METHODS

Retrospective analyses were conducted in 197 patients with basal ganglia hemorrhage (training cohort: n = 136, test cohort: n = 61) who were admitted to The First Affiliated Hospital of Shandong First Medical University (Shandong Provincial Qianfoshan Hospital) and underwent computed tomography (CT) scan. According to different prognoses, patients with basal ganglia hemorrhage were divided into two groups. Independent clinical risk factors were derived with univariate and multivariate regression analysis. Radiomics signatures were obtained using least absolute shrinkage and selection operator. A radiomics score (Rad-score) was generated by 12 radiomics signatures of perihematomal edema (PHE) from CT images that were correlated with the prognosis of basal ganglia hemorrhage patients. A clinical-radiomics nomogram was conducted by combing the Rad-score and clinical risk factors using logistic regression analysis. The prediction performance of the nomogram was tested in the training cohort and verified in the test cohort.

RESULTS

The clinical model conducted by four clinical risk factors and 12 radiomcis features were used to establish the Rad-score. The clinical-radiomics nomogram outperformed the clinical model in the training cohort [area under the curve (AUC), 0.92 vs. 0.85] and the test cohort (AUC, 0.91 vs 0.85). The clinical-radiomics nomogram showed good calibration and clinical benefit in both the training and test cohorts.

CONCLUSION

Radiomics features of PHE in patients with basal ganglia hemorrhage could contribute to the outcome prediction. The clinical-radiomics nomogram may help first-line clinicians to make individual clinical treatment decisions for patients with basal ganglia hemorrhage.

Anthrax Meningoencephalitis and Intracranial Hemorrhage

The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage, including subarachnoid and intracerebral hemorrhage. Higher mortality than other forms of bacterial meningitis suggests that antimicrobials and cardiopulmonary support alone may be insufficient and that strategies targeting the hemorrhage might improve outcomes. In this review, we describe the toxic role of intracranial hemorrhage in anthrax meningoencephalitis. We first examine the high incidence of intracranial hemorrhage in patients with anthrax meningoencephalitis. We then review common diseases that present with intracranial hemorrhage, including aneurysmal subarachnoid hemorrhage and spontaneous intracerebral hemorrhage, postulating applicability of established and potential neurointensive treatments to the multimodal management of hemorrhagic anthrax meningoencephalitis. Finally, we examine the therapeutic potential of minocycline, an antimicrobial that is effective against B. anthracis and that has been shown in preclinical studies to have neuroprotective properties, which thus might be repurposed for this historically fatal disease.

Experimental study of new derivatives of 3-hydroxypyridine as pharmacological agents for the correction of ischemic brain injury after intracerebral hemorrhage

Introduction: Limiting the action of secondary injury factors can improve the prognosis in acute cerebral accidents. The aim of the investigation is to study the neuroprotective effects of 3-hydroxypyridine derivatives.

Materials and methods: The study was performed in Wistar rats. An intracerebral hemorrhage (ICH) model was used. The animals were once administered intraperitoneally with the test drugs 1 hour before the surgery and on the 1st, 2nd and 3rd days. The registration of behaviors and condition of the animals on days 1, 3, 7 and 14 and the morphological examination of the brain were performed.

Results and discussion: The use of the substances LKhT 4-97 and LKhT 11-02 in the treatment of experimental ICH had a positive effect on the survival rate of the animals and on the resolution rate of pathological signs (p<0.05). Clinical observations were confirmed by the results of analysis of the S100b brain damage marker and morphometry. The efficacy of LKhT 3-15 was largely comparable to that of the reference drug Mexidol. The efficacy of LKhT 01-09 was significantly inferior to that of the reference drug Mexidol. Differences in the neuroprotective effects of the studied substances are related to the metabolism of their various pharmacophores. A hypothetical mechanism for the induction of their neuroprotective effects has been proposed.

Conclusion: Three of the four 3-hydroxypyridine derivatives under study have a neuroprotective effect, which is manifested in a more rapid resolution of pathological symptoms and less pronounced signs of neurodegeneration.

LncRNA TCONS_00145741 Knockdown Prevents Thrombin-Induced M1 Differentiation of Microglia in Intracerebral Hemorrhage by Enhancing the Interaction Between DUSP6 and JNK

Background: The differentiation of microglia from M1 to M2 exerts a pivotal role in the aggression of intracerebral hemorrhage (ICH), and long non-coding RNAs (lncRNAs) are associated with the differentiation of microglia. However, the underlying mechanism had not been fully clarified. Methods: The expression profile of lncRNAs in thrombin-induced primary microglia was analyzed by RNA sequencing. Under thrombin treatment, the effect of lncRNA TCONS_00145741 on the differentiation of microglia was determined by immunofluorescence staining, quantitative real-time PCR, and Western blot. The potential mechanism and related signaling pathways of TCONS_00145741 in the M1 and M2 differentiation of microglia in ICH were assessed by Gene Ontology analysis, flow cytometry, RNA pull-down, RNA Immunoprecipitation, and RNA fluorescence in situ hybridization followed by immunofluorescence analysis. Results: LncRNA TCONS_00145741 expression was elevated in the thrombin-induced primary microglia, and the interference with TCONS_00145741 restrained the M1 differentiation of microglia and facilitated the M2 differentiation under thrombin treatment. The interference with TCONS_00145741 restrained the activation of the JNK pathway in microglia under thrombin treatment and repressed the JNK phosphorylation levels by enhancing the interaction between DUSP6 and JNK. In vivo experiments further illustrated that the interference with TCONS_00145741 alleviated ICH. Conclusion: LncRNA TCONS_00145741 knockdown prevented thrombin-induced M1 differentiation of microglia in ICH by enhancing the interaction between DUSP6 and JNK. This study might provide a promising target for the clinical treatment of ICH.

Zhuyu Annao decoction promotes angiogenesis in mice with cerebral hemorrhage by inhibiting the activity of PHD3

Some traditional Chinese decoctions, such as Zhuyu Annao, exert favorable therapeutic effects on acute cerebral hemorrhage, hemorrhagic stroke, and other neurological diseases, but the underlying mechanism remains unclear. This study aimed to determine whether Zhuyu Annao decoction (ZYAND) protects the injured brain by promoting angiogenesis following intracerebral hemorrhage (ICH) and elucidate its specific mechanism. The effect of ZYAND on the nervous system of mice after ICH was explored through behavioral experiments, such as the Morris water maze and Rotarod tests, and its effects on oxidative stress were explored by detecting several oxidative stress markers, including malondialdehyde, nitric oxide, glutathione peroxidase, and superoxide dismutase. Real-time quantitative RT-PCR and WB were used to detect the effects of ZYAND on the levels of prolyl hydroxylase domain 3 (PHD3), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) in the brain tissues of mice. The effect of ZYAND on the NF-κB signaling pathway was detected using a luciferase reporter gene. A human umbilical cord vascular endothelial cell angiogenesis experiment was performed to determine whether ZYAND promotes angiogenesis. The Morris water maze test and other behavioral experiments verified that ZYAND improved the neurobehavior of mice after ICH. ZYAND activated the PHD3/HIF-1α signaling pathway, inhibiting the oxidative damage caused by ICH. In angiogenesis experiments, it was found that ZYAND promoted VEGF-induced angiogenesis by upregulating the expression of HIF-1α, and NF-κB signaling regulated the expression of HIF-1α by inhibiting PHD3. ZYAND exerts a reparative effect on brain tissue damaged after ICH through the NF-κB/ PHD3/HIF-1α/VEGF signaling axis.

What is the Role of Hyperosmolar Therapy in Hemispheric Stroke Patients?

The role of hyperosmolar therapy (HT) in large hemispheric ischemic or hemorrhagic strokes remains a controversial issue. Past and current stroke guidelines state that it represents a reasonable therapeutic measure for patients with either neurological deterioration or intracranial pressure (ICP) elevations documented by ICP monitoring. However, the lack of evidence for a clear effect of this therapy on radiological tissue shifts and clinical outcomes produces uncertainty with respect to the appropriateness of its implementation and duration in the context of radiological mass effect without clinical correlates of neurological decline or documented elevated ICP. In addition, limited data suggest a theoretical potential for harm from the prophylactic and protracted use of HT in the setting of large hemispheric lesions. HT exerts effects on parenchymal volume, cerebral blood volume and cerebral perfusion pressure which may ameliorate global ICP elevation and cerebral blood flow; nevertheless, it also holds theoretical potential for aggravating tissue shifts promoted by significant interhemispheric ICP gradients that may arise in the setting of a large unilateral supratentorial mass lesion. The purpose of this article is to review the literature in order to shed light on the effects of HT on brain tissue shifts and clinical outcome in the context of large hemispheric strokes, as well as elucidate when HT should be initiated and when it should be avoided.

Hemorrhagic stroke

Hemorrhagic stroke comprises about 20% of all strokes, with intracerebral hemorrhage (ICH) being the most common type. Frequency of ICH is increased where hypertension is untreated. ICH in particularly has a disproportionately high risk of early mortality and long-term disability. Until recently, there has been a paucity of randomized controlled trials (RCTs) to provide evidence for the efficacy of various commonly considered interventions in ICH, including acute blood pressure management, coagulopathy reversal, and surgical hematoma evacuation. Evidence-based guidelines do exist for ICH and these form the basis for a framework of care. Current approaches emphasize control of extremely high blood pressure in the acute phase, rapid reversal of vitamin K antagonists, and surgical evacuation of cerebellar hemorrhage. Lingering questions, many of which are the topic of ongoing clinical research, include optimizing individual blood pressure targets, reversal strategies for newer anticoagulant medications, and the role of minimally invasive surgery. Risk stratification models exist, which derive from findings on clinical exam and neuroimaging, but care should be taken to avoid a self-fulfilling prophecy of poor outcome from limiting treatment due to a presumed poor prognosis. Cerebral venous thrombosis is an additional subtype of hemorrhagic stroke that has a unique set of causes, natural history, and treatment and is discussed as well.

Clinical pattern and predictors of stroke treatment outcome among hospitalised patients who had a stroke at Felege Hiwot comprehensive specialised hospital, northwest Ethiopia: a retrospective cross-sectional study

OBJECTIVES

This study aimed to assess the clinical pattern and predictors of stroke treatment outcomes among hospitalised patients in Felege Hiwot comprehensive specialised hospital (FHCSH) in northwest Ethiopia.

DESIGN

A retrospective cross-sectional study.

SETTING

The study was conducted medical ward of FHCSH.

PARTICIPANTS

The medical records of 597 adult patients who had a stroke were included in the study. All adult (≥18 years) patients who had a stroke had been admitted to the medical ward of FHSCH during 2015-2019 were included in the study. However, patients with incomplete medical records (ie, incomplete treatment regimen and the status of the patients after treatment) were excluded in the study.

RESULTS

In the present study, 317 (53.1%) were males, and the mean age of the study participants was 61.08±13.76 years. About two-thirds of patients (392, 65.7%) were diagnosed with ischaemic stroke. Regarding clinical pattern, about 203 (34.0%) of patients complained of right-side body weakness and the major comorbid condition identified was hypertension (216, 64.9%). Overall, 276 (46.2%) of them had poor treatment outcomes, and 101 (16.9%) of them died. Patients who cannot read and write (AOR=42.89, 95% CI 13.23 to 111.28, p<0.001), attend primary school (AOR=22.11, 95% CI 6.98 to 55.99, p<0.001) and secondary school (AOR=4.20, 95% CI 1.42 to 12.51, p<0.001), diagnosed with haemorrhagic stroke (AOR=2.68, 95% CI 1.62 to 4.43, p<0.001) and delayed hospital arrival more than 24 hours (AOR=2.92, 95% CI 1.83 to 4.66, p=0.001) were the independent predictors of poor treatment outcome.

CONCLUSIONS

Approximately half of the patients who had a stroke had poor treatment outcomes. Ischaemic stroke was the most predominantly diagnosed stroke type. Education status, types of stroke and the median time from onset of symptoms to hospitalisation were the predictors of treatment outcome. Health education should be given to patients regarding clinical symptoms of stroke. In addition, local healthcare providers need to consider the above risk factors while managing stroke.

NOD1/RIP2 signalling enhances the microglia-driven inflammatory response and undergoes crosstalk with inflammatory cytokines to exacerbate brain damage following intracerebral haemorrhage in mice

BACKGROUND

Secondary brain damage caused by the innate immune response and subsequent proinflammatory factor production is a major factor contributing to the high mortality of intracerebral haemorrhage (ICH). Nucleotide-binding oligomerization domain 1 (NOD1)/receptor-interacting protein 2 (RIP2) signalling has been reported to participate in the innate immune response and inflammatory response. Therefore, we investigated the role of NOD1/RIP2 signalling in mice with collagenase-induced ICH and in cultured primary microglia challenged with hemin.

METHODS

Adult male C57BL/6 mice were subjected to collagenase for induction of ICH model in vivo. Cultured primary microglia and BV2 microglial cells (microglial cell line) challenged with hemin aimed to simulate the ICH model in vitro. We first defined the expression of NOD1 and RIP2 in vivo and in vitro using an ICH model by western blotting. The effect of NOD1/RIP2 signalling on ICH-induced brain injury volume, neurological deficits, brain oedema, and microglial activation were assessed following intraventricular injection of either ML130 (a NOD1 inhibitor) or GSK583 (a RIP2 inhibitor). In addition, levels of JNK/P38 MAPK, IκBα, and inflammatory factors, including tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS) expression, were analysed in ICH-challenged brain and hemin-exposed cultured primary microglia by western blotting. Finally, we investigated whether the inflammatory factors could undergo crosstalk with NOD1 and RIP2.

RESULTS

The levels of NOD1 and its adaptor RIP2 were significantly elevated in the brains of mice in response to ICH and in cultured primary microglia, BV2 cells challenged with hemin. Administration of either a NOD1 or RIP2 inhibitor in mice with ICH prevented microglial activation and neuroinflammation, followed by alleviation of ICH-induced brain damage. Interestingly, the inflammatory factors interleukin (IL)-1β and tumour necrosis factor-α (TNF-α), which were enhanced by NOD1/RIP2 signalling, were found to contribute to the NOD1 and RIP2 upregulation in our study.

CONCLUSION

NOD1/RIP2 signalling played an important role in the regulation of the inflammatory response during ICH. In addition, a vicious feedback cycle was observed between NOD1/RIP2 and IL-1β/TNF-α, which could to some extent result in sustained brain damage during ICH. Hence, our study highlights NOD1/RIP2 signalling as a potential therapeutic target to protect the brain against secondary brain damage during ICH.

Advances in Therapeutic Approaches for Spontaneous Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) results in high rates of morbidity and mortality, with intraventricular hemorrhage (IVH) being associated with even worse outcomes. Therapeutic interventions in acute ICH have continued to emerge with focus on arresting hemorrhage expansion, clot volume reduction of both intraventricular and parenchymal hematomas, and targeting perihematomal edema and inflammation. Large randomized controlled trials addressing the effectiveness of rapid blood pressure lowering, hemostatic therapy with platelet transfusion, and other clotting complexes and hematoma volume reduction using minimally invasive techniques have impacted clinical guidelines. We review the recent evolution in the management of acute spontaneous ICH, discussing which interventions have been shown to be safe and which may potentially improve outcomes.

Assessment of the Patient With Intracerebral Hemorrhage: A Review of the Literature

Spontaneous nontraumatic intracerebral hemorrhage is associated with high morbidity and mortality. Given the risk of rapid neurological deterioration, early identification with rapid neuroimaging is vital. Predictors of outcome, such as spot sign and intracerebral hemorrhage score, can help guide management goals. Management should be aimed at prevention of hematoma expansion, treatment of increased intracranial pressure, and prevention of secondary brain injury and medical complications.

Guidelines for the Acute Treatment of Cerebral Edema in Neurocritical Care Patients

BACKGROUND

Acute treatment of cerebral edema and elevated intracranial pressure is a common issue in patients with neurological injury. Practical recommendations regarding selection and monitoring of therapies for initial management of cerebral edema for optimal efficacy and safety are generally lacking. This guideline evaluates the role of hyperosmolar agents (mannitol, HTS), corticosteroids, and selected non-pharmacologic therapies in the acute treatment of cerebral edema. Clinicians must be able to select appropriate therapies for initial cerebral edema management based on available evidence while balancing efficacy and safety.

METHODS

The Neurocritical Care Society recruited experts in neurocritical care, nursing, and pharmacy to create a panel in 2017. The group generated 16 clinical questions related to initial management of cerebral edema in various neurological insults using the PICO format. A research librarian executed a comprehensive literature search through July 2018. The panel screened the identified articles for inclusion related to each specific PICO question and abstracted necessary information for pertinent publications. The panel used GRADE methodology to categorize the quality of evidence as high, moderate, low, or very low based on their confidence that the findings of each publication approximate the true effect of the therapy.

RESULTS

The panel generated recommendations regarding initial management of cerebral edema in neurocritical care patients with subarachnoid hemorrhage, traumatic brain injury, acute ischemic stroke, intracerebral hemorrhage, bacterial meningitis, and hepatic encephalopathy.

CONCLUSION

The available evidence suggests hyperosmolar therapy may be helpful in reducing ICP elevations or cerebral edema in patients with SAH, TBI, AIS, ICH, and HE, although neurological outcomes do not appear to be affected. Corticosteroids appear to be helpful in reducing cerebral edema in patients with bacterial meningitis, but not ICH. Differences in therapeutic response and safety may exist between HTS and mannitol. The use of these agents in these critical clinical situations merits close monitoring for adverse effects. There is a dire need for high-quality research to better inform clinicians of the best options for individualized care of patients with cerebral edema.

Antihyperthermic treatment decreases perihematomal hypodensity

OBJECTIVE

To investigate the effect on perihematomal hypodensity and outcome of a decrease in body temperature in the first 24 hours in patients with intracerebral hemorrhage (ICH).

METHODS

In this retrospective study on a prospectively registered database, among the 1,100 patients, 795 met all the inclusion criteria. Temperature variations in the first 24 hours and perihematomal hypodensity (PHHD) were recorded. Patients ≥37.5°C were treated with antihyperthermic drugs for at least 48 hours. The main objective was to determine the association among temperature variation, PHHD, and outcome at 3 months.

RESULTS

The decrease in temperature in the first 24 hours increased the possibility of good outcome 11-fold. Temperature decrease, lower PHHD volume, and a good outcome were observed in 31.8% of the patients who received antihyperthermic treatment.

CONCLUSION

The administration of early antihyperthermic treatment in patients with spontaneous ICH with a basal axillary temperature ≥37.5°C resulted in good outcome in a third of the treated patients.

Fluids and hyperosmolar agents in neurocritical care: an update

PURPOSE OF REVIEW

To discuss recent updates in fluid management and use of hyperosmolar therapy in neurocritical care.

RECENT FINDINGS

Maintaining euvolemia with crystalloids seems to be the recommended fluid resuscitation for neurocritical care patients. Buffered crystalloids have been shown to reduce hyperchloremia in patients with subarachnoid hemorrhage without causing hyponatremia or hypo-osmolality. In addition, in patients with traumatic brain injury, buffered solutions reduce the incidence of hyperchloremic acidosis but are not associated with intracranial pressure (ICP) alteration. Both mannitol and hypertonic saline are established as effective hyperosmolar agents to control ICP. Both agents have been shown to control ICP, but their effects on neurologic outcomes are unclear. A recent surge in preference for using hypertonic saline as a hyperosmolar agent is based on few studies without strong evidence.

SUMMARY

Fluid resuscitation with crystalloids seems to be reasonable in this setting although no recommendations can be made regarding type of crystalloids. Based on current evidence, elevated ICP can be effectively reduced by either hypertonic saline or mannitol.

An update on neurocritical care for intracerebral hemorrhage

Introduction: Intracerebral hemorrhage remains one of the leading causes of death and disability worldwide with few established interventions that improve neurologic outcome. Research dedicated to better understanding and treating hemorrhagic strokes has multiplied in the past decade. Areas Covered: This review aims to discuss the current landscape of management of intracerebral hemorrhage in a critical care setting and provide updates regarding developments in therapeutic interventions and targets. PubMed was utilized to review recent literature, with a focus on large trials and meta-analyses, which have shaped current practice. Published committee guidelines were also included. A focus was placed on research published after 2015 in an effort to supplement previous reviews included in this publication. Expert Opinion: Literature pertaining to ICH management has allowed for a greater understanding of ineffective strategies as opposed to those of benefit. Despite this, mortality has improved worldwide, which may be the result of growing research efforts. Areas of future research that will impact mortality and improve neurologic outcomes include prevention of hematoma expansion, optimization of blood pressure targets, effective coagulopathy reversal, and minimally invasive surgical techniques to reduce hematoma burden.

Advancements in Managing Intracerebral Hemorrhage: Transition from Nihilism to Optimism

There have been significant advancements in the management of intracerebral hemorrhage (ICH) stemming from new knowledge on its pathogenesis. Major clinical trials, such as Surgical Trial in Lobar Intracerebral Hemorrhage (STICH I and II), have shown only a small, albeit clinically relevant, advantage of surgical interventions in specific subsets of patients suffering from ICH. Currently, the aim is to use a minimally invasive and safe trajectory in removing significant brain hematomas with the aid of neuro-endoscopy or precise guidance through neuro-navigation, thereby avoiding a collateral damage to the surrounding normal brain tissue. A fundamental rational to such approach is to safely remove hematoma, preventing the ongoing mass effect resulting in brain herniation, and to minimize deleterious effects of iron released from hematoma to brain cells. The clot lysis process is facilitated with the adjunctive use of recombinant tissue plasminogen activator and sonolysis. Revised recommendations for the management of ICH focus on a holistic approach, with special emphasis on early patient mobilization and graded rehabilitative process. There has been a paradigm shift in the management algorithm, putting emphasis on early and safe removal of brain hematoma and then focusing on the improvement of patients' quality of life. We have made significant progress in transition from nihilism toward optimism, based on evidence-based management of such a severe global health scourge as intracranial hemorrhage.

Acute Treatment of Stroke (Except Thrombectomy)

PURPOSE OF REVIEW

The management of patients with acute stroke has been revolutionized in recent years with the advent of new effective treatments. In this rapidly evolving field, we provide an update on the management of acute stroke excluding thrombectomy, looking to recent, ongoing, and future trials.

RECENT FINDINGS

Large definitive trials have provided insight into acute stroke care including broadening the therapeutic window for thrombolysis, alternatives to standard dose alteplase, the use of dual antiplatelet therapy early after minor ischemic stroke, and treating elevated blood pressure in intracerebral hemorrhage. Further ongoing and future trials are eagerly awaited in this ever-expanding area. Although definitive trials have led to improvements in acute stroke care, there remains a need for further research to improve our understanding of pathophysiological mechanisms underlying different stroke types with the potential for treatments to be tailored to the individual.

Increased BBB Permeability Enhances Activation of Microglia and Exacerbates Loss of Dendritic Spines After Transient Global Cerebral Ischemia

Ischemic stroke can induce rapid disruption of blood-brain barrier (BBB). It has been suggested that increased BBB permeability can affect the pathological progression of ischemic tissue. However, the impact of increased BBB permeability on microglial activation and synaptic structures following reperfusion after ischemia remains unclear. In this study, we investigated microglial activation, dendritic damage and plasticity of dendritic spines after increasing BBB permeability following transient global cerebral ischemia in the somatosensory cortices in mice. Bilateral common carotid artery ligation (BCAL) was used to induce transient global cerebral ischemia. Mannitol was used to increase the BBB permeability. Intravital two-photon imaging was performed to image the dendritic structures and BBB extravasation. Microglial morphology was quantitated using a skeletonization analysis method. To evaluate inflammation of cerebral cortex, the mRNA expression levels of integrin alpha M (CD11b), CD68, chemokine (C-X-C motif) ligand 10 (IP10) and tumor necrosis factor alpha (TNF-α) were measured by fluorescent quantitative PCR. Intravital two-photon imaging revealed that mannitol caused a drastic increase in BBB extravasation during reperfusion after transient global ischemia. Increased BBB permeability induced by mannitol had no significant effect on inflammation and dendritic spines in healthy mice but triggered a marked de-ramification of microglia; importantly, in ischemic animals, mannitol accelerated de-ramification of microglia and aggravated inflammation at 3 h but not at 3 days following reperfusion after ischemia. Although mannitol did not cause significant change in the percentage of blebbed dendrites and did not affect the reversible recovery of the dendritic structures, excessive extravasation was accompanied with significant decrease in spine formation and increase in spine elimination during reperfusion in ischemic mice. These findings suggest that increased BBB permeability induced by mannitol can lead to acute activation of microglia and cause excessive loss of dendritic spines after transient global cerebral ischemia.

Intensive Care Unit Admission for Patients in the INTERACT2 ICH Blood Pressure Treatment Trial: Characteristics, Predictors, and Outcomes

BACKGROUND

Wide variation exists in criteria for accessing intensive care unit (ICU) facilities for managing patients with critical illnesses such as acute intracerebral hemorrhage (ICH). We aimed to determine the predictors of admission, length of stay, and outcome for ICU among participants of the main Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2).

METHODS

INTERACT2 was an international, open, blinded endpoint, randomized controlled trial of 2839 ICH patients (<6 h) and elevated systolic blood pressure (SBP) allocated to receive intensive (target SBP <140 mmHg within 1 h) or guideline-recommended (target SBP <180 mmHg) BP-lowering treatment. The primary outcome was death or major disability, defined by modified Rankin scale scores 3-6 at 90 days. Logistic regression and propensity score analyses were used to determine independent associations.

MAIN RESULTS

Predictors of ICU admission included younger age, recruitment in China, prior ischemic/undetermined stroke, high SBP, severe stroke [National Institute of Health stroke scale (NIHSS) score ≥15], large ICH volume (≥15 mL), intraventricular hemorrhage (IVH) extension, early neurological deterioration, intubation and surgery. Determinants of prolonged ICU stay (≥5 days) were prior antihypertensive use, NIHSS ≥15, large ICH volume, lobar ICH location, IVH, early neurological deterioration, intubation and surgery. ICU admission was associated with higher-risk major disability at 90-day assessment compared to those without ICU admission.

CONCLUSIONS

This study presents prognostic variables for ICU management and outcome of ICH patients included in a large international cohort. These data may assist in the selection and counseling of patients and families concerning ICU admission.

Selective NLRP3 (Pyrin Domain-Containing Protein 3) Inflammasome Inhibitor Reduces Brain Injury After Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Intracerebral hemorrhage (ICH) is a devastating disease without effective treatment. As a key component of the innate immune system, the NOD-like receptor (NLR) family, NLRP3 (pyrin domain-containing protein 3) inflammasome, when activated after ICH, promotes neuroinflammation and brain edema. MCC950 is a potent, selective, small-molecule NLRP3 inhibitor that blocks NLRP3 activation at nanomolar concentrations. Here, we examined the effect of MCC950 on brain injury and inflammation in 2 models of ICH in mice.

METHODS

In mice with ICH induced by injection of autologous blood or bacterial collagenase, we determined the therapeutic potential of MCC950 and its mechanisms of neuroprotection.

RESULTS

MCC950 reduced IL-1β (interleukin-1β) production and attenuated neurodeficits and perihematomal brain edema after ICH induction by injection of either autologous blood or collagenase. In mice with autologous blood-induced ICH, the protection of MCC950 was associated with reduced leukocyte infiltration into the brain and microglial production of IL-6. MCC950 improved blood-brain barrier integrity and diminished cell death. Notably, the protective effect of MCC950 was abolished in mice depleted of either microglia or Gr-1⁺ myeloid cells.

CONCLUSIONS

These results indicate that the NLRP3 inflammasome inhibitor, MCC950, attenuates brain injury and inflammation after ICH. Hence, NLRP3 inflammasome inhibition is a potential therapy for ICH that warrants further investigation.

[Current treatment concepts in intracerebral hemorrhage]

BACKGROUND AND OBJECTIVE

In recent years, various important studies investigating the management of intracerebral hemorrhage (ICH) have been published. However, these have not entered guideline recommendations yet. Therefore, essential results are summarized here and the findings are integrated into current treatment concepts.

MATERIALS AND METHODS

Based on a dedicated literature review and the authors' experience, up-to-date and high-quality investigations were identified.

RESULTS AND DISCUSSION

Randomized data and meta-analyses provide evidence that aggressive blood-pressure reduction (targeting a systolic blood pressure <140 mm Hg) appears safe and reduces hematoma enlargement. ICH associated with intake of vitamin K antagonists should be reversed immediately using prothrombin complex concentrates (PCC) and vitamin K, targeting at least international normalized ratio levels below 1.3. For dabigatran-related ICH, an antidote (idarucizumab) is available for reversal, but in ICH under the use of factor Xa inhibitors evidence is poor. However, reversal should be carried out using high-dosed PCC (50 IU/kg PCC). Routine hematoma evacuation surgery cannot be advocated, yet new minimally invasive strategies provide promising results. In patients with acute occlusive hydrocephalus, an external ventricular drain should be placed and utilizing intraventricular lysis appears safe, reduces mortality, and is associated with improved functional outcome. Adding lumbar drainage to this treatment strategy may reduce permanent shunt dependency. The sum of treatment measures and specialized care at high-volume centers improves outcome in patients with ICH.

Preclinical Studies and Translational Applications of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) which refers to bleeding in the brain is a very deleterious condition with high mortality and disability rate. Surgery or conservative therapy remains the treatment option. Various studies have divided the disease process of ICH into primary and secondary injury, for which knowledge into these processes has yielded many preclinical and clinical treatment options. The aim of this review is to highlight some of the new experimental drugs as well as other treatment options like stem cell therapy, rehabilitation, and nanomedicine and mention some translational clinical applications that have been done with these treatment options.

A TSPO ligand attenuates brain injury after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating disease without effective treatment. After ICH, the immediate infiltration of leukocytes and activation of microglia are accompanied by a rapid up-regulation of the 18-kDa translocator protein (TSPO). TSPO ligands have shown anti-inflammatory and neuroprotective properties in models of CNS injury. In this study, we determined the impact of a TSPO ligand, etifoxine, on brain injury and inflammation in 2 mouse models of ICH. TSPO was up-regulated in Iba1⁺ cells from brains of patients with ICH and in CD11b⁺CD45^int cells from mice subjected to collagenase-induced ICH. Etifoxine significantly reduced neurodeficits and perihematomal brain edema after ICH induction by injection of either autologous blood or collagenase. In collagenase-induced ICH mice, the protection of etifoxine was associated with reduced leukocyte infiltration into the brain and microglial production of IL-6 and TNF-α. Etifoxine improved blood–brain barrier integrity and diminished cell death. Notably, the protective effect of etifoxine was abolished in mice depleted of microglia by using a colony-stimulating factor 1 receptor inhibitor. These results indicate that the TSPO ligand etifoxine attenuates brain injury and inflammation after ICH. TSPO may be a viable therapeutic target that requires further investigations in ICH.—Li, M., Ren, H., Sheth, K. N., Shi, F.-D., Liu, Q. A TSPO ligand attenuates brain injury after intracerebral hemorrhage.

Current management of spontaneous intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is the most devastating and disabling type of stroke. Uncontrolled hypertension (HTN) is the most common cause of spontaneous ICH. Recent advances in neuroimaging, organised stroke care, dedicated Neuro-ICUs, medical and surgical management have improved the management of ICH. Early airway protection, control of malignant HTN, urgent reversal of coagulopathy and surgical intervention may increase the chance of survival for patients with severe ICH. Intensive lowering of systolic blood pressure to <140 mm Hg is proven safe by two recent randomised trials. Transfusion of platelets in patients on antiplatelet therapy is not indicated unless the patient is scheduled for surgical evacuation of haematoma. In patients with small haematoma without significant mass effect, there is no indication for routine use of mannitol or hypertonic saline (HTS). However, for patients with large ICH (volume > 30 cbic centmetre) or symptomatic perihaematoma oedema, it may be beneficial to keep serum sodium level at 140–150 mEq/L for 7–10 days to minimise oedema expansion and mass effect. Mannitol and HTS can be used emergently for worsening cerebral oedema, elevated intracranial pressure (ICP) or pending herniation. HTS should be administered via central line as continuous infusion (3%) or bolus (23.4%). Ventriculostomy is indicated for patients with severe intraventricular haemorrhage, hydrocephalus or elevated ICP. Patients with large cerebellar or temporal ICH may benefit from emergent haematoma evacuation. It is important to start intermittent pneumatic compression devices at the time of admission and subcutaneous unfractionated heparin in stable patients within 48 hours of admission for prophylaxis of venous thromboembolism. There is no benefit for seizure prophylaxis or aggressive management of fever or hyperglycaemia. Early aggressive comprehensive care may improve survival and functional recovery.

Medical management of intracerebral haemorrhage

The global burden of intracerebral haemorrhage (ICH) is enormous. Developing evidence-based management strategies for ICH has been hampered by its diverse aetiology, high case fatality and variable cooperative organisation of medical and surgical care. Progress is being made through the conduct of collaborative multicentre studies with the large sample sizes necessary to evaluate therapies with realistically modest treatment effects. This narrative review describes the major consequences of ICH and provides evidence-based recommendations to support decision-making in medical management.

Intracerebral Hemorrhage: Perihemorrhagic Edema and Secondary Hematoma Expansion: From Bench Work to Ongoing Controversies

Intracerebral hemorrhage (ICH) is a medical emergency, which often leads to severe disability and death. ICH-related poor outcomes are due to primary injury causing structural damage and mass effect and secondary injury in the perihemorrhagic region over several days to weeks. Secondary injury after ICH can be due to hematoma expansion (HE) or a consequence of repair pathway along the continuum of neuroinflammation, neuronal death, and perihemorrhagic edema (PHE). This review article is focused on PHE and HE and will cover the animal studies, related human studies, and clinical trials relating to these mechanisms of secondary brain injury in ICH patients.

Breaking the Blood-Brain Barrier With Mannitol to Aid Stem Cell Therapeutics in the Chronic Stroke Brain

Blood-brain barrier (BBB) permeabilizers, such as mannitol, can facilitate peripherally delivered stem cells to exert therapeutic benefits on the stroke brain. Although this BBB permeation-aided stem cell therapy has been demonstrated in the acute stage of stroke, such BBB permeation in the chronic stage of the disease remains to be examined. Adult Sprague-Dawley rats initially received sham surgery or experimental stroke via the 1-h middle cerebral artery occlusion (MCAo) model. At 1 month after the MCAo surgery, stroke animals were randomly assigned to receive human umbilical cord stem cells only (2 million viable cells), mannitol only (1.1 mol/L mannitol at 4°C), combined human umbilical cord stem cells (200,000 viable cells) and mannitol (1.1 mol/L mannitol at 4°C), and vehicle (phosphate-buffered saline) only. Stroke animals that received human umbilical cord blood cells alone or combined human umbilical cord stem cells and mannitol exhibited significantly improved motor performance and significantly better brain cell survival in the peri-infarct area compared to stroke animals that received vehicle or mannitol alone, with mannitol treatment reducing the stem cell dose necessary to afford functional outcomes. Enhanced neurogenesis in the subventricular zone accompanied the combined treatment of human umbilical cord stem cells and mannitol. We showed that BBB permeation facilitates the therapeutic effects of a low dose of peripherally transplanted stem cells to effectively cause functional improvement and increase neurogenesis in chronic stroke.

Treatment of Edema Associated With Intracerebral Hemorrhage

OPINION STATEMENT

Cerebral edema (i.e., "brain swelling") is a common complication following intracerebral hemorrhage (ICH) and is associated with worse clinical outcomes. Perihematomal edema (PHE) accumulates during the first 72 h after hemorrhage, and during this period, patients are at risk of clinical deterioration due to the resulting tissue shifts and brain herniation. First-line medical therapies for patients symptomatic of PHE include osmotic agents, such as mannitol in low- or high-dose bolus form, or boluses of hypertonic saline (HTS) at varied concentrations with or without subsequent continuous infusion. Decompressive craniectomy may be required for symptomatic edema refractory to osmotherapy. Other strategies that reduce PHE such as hypothermia and minimally invasive surgery have shown promise in pilot studies and are currently being evaluated in larger clinical trials. Ongoing basic, translational, and clinical research seek to better elucidate the pathophysiology of PHE to identify novel strategies to prevent edema formation as a next major advance in the treatment of ICH.