Acute systemic erythropoietin therapy to reduce delayed ischemic deficits following aneurysmal subarachnoid hemorrhage: a Phase II randomized, double-blind, placebo-controlled trial

Pitfalls of single-study external validation illustrated with a model predicting functional outcome after aneurysmal subarachnoid hemorrhage

BACKGROUND

Prediction models are often externally validated with data from a single study or cohort. However, the interpretation of performance estimates obtained with single-study external validation is not as straightforward as assumed. We aimed to illustrate this by conducting a large number of external validations of a prediction model for functional outcome in subarachnoid hemorrhage (SAH) patients.

METHODS

We used data from the Subarachnoid Hemorrhage International Trialists (SAHIT) data repository (n = 11,931, 14 studies) to refit the SAHIT model for predicting a dichotomous functional outcome (favorable versus unfavorable), with the (extended) Glasgow Outcome Scale or modified Rankin Scale score, at a minimum of three months after discharge. We performed leave-one-cluster-out cross-validation to mimic the process of multiple single-study external validations. Each study represented one cluster. In each of these validations, we assessed discrimination with Harrell's c-statistic and calibration with calibration plots, the intercepts, and the slopes. We used random effects meta-analysis to obtain the (reference) mean performance estimates and between-study heterogeneity (I2-statistic). The influence of case-mix variation on discriminative performance was assessed with the model-based c-statistic and we fitted a "membership model" to obtain a gross estimate of transportability.

RESULTS

Across 14 single-study external validations, model performance was highly variable. The mean c-statistic was 0.74 (95%CI 0.70-0.78, range 0.52-0.84, I2 = 0.92), the mean intercept was -0.06 (95%CI -0.37-0.24, range -1.40-0.75, I2 = 0.97), and the mean slope was 0.96 (95%CI 0.78-1.13, range 0.53-1.31, I2 = 0.90). The decrease in discriminative performance was attributable to case-mix variation, between-study heterogeneity, or a combination of both. Incidentally, we observed poor generalizability or transportability of the model.

CONCLUSIONS

We demonstrate two potential pitfalls in the interpretation of model performance with single-study external validation. With single-study external validation. (1) model performance is highly variable and depends on the choice of validation data and (2) no insight is provided into generalizability or transportability of the model that is needed to guide local implementation. As such, a single single-study external validation can easily be misinterpreted and lead to a false appreciation of the clinical prediction model. Cross-validation is better equipped to address these pitfalls.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

White Matter Injury: An Emerging Potential Target for Treatment after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) refers to vascular brain injury mainly from a ruptured aneurysm, which has a high lifetime risk and imposes a substantial burden on patients, families, and society. Previous studies on SAH mainly focused on neurons in gray matter (GM). However, according to literature reports in recent years, in-depth research on the mechanism of white matter (WM) is of great significance to injury and recovery after SAH. In terms of functional recovery after SAH, all kinds of cells in the central nervous system (CNS) should be protected. In other words, it is necessary to protect not only GM but also WM, not only neurons but also glial cells and axons, and not only for the lesion itself but also for the prevention and treatment of remote damage. Clarifying the mechanism of white matter injury (WMI) and repair after SAH is of great importance. Therefore, this present review systematically summarizes the current research on WMI after SAH, which might provide therapeutic targets for treatment after SAH.

Prophylactic Therapies for Morbidity and Mortality After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Network Meta-Analysis of Randomized Trials

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and morbidity. We aimed to determine the relative benefits of pharmacological prophylactic treatments in patients with aneurysmal subarachnoid hemorrhage by performing a network meta-analysis of randomized trials.

METHODS

We searched Medline, Web of Science, Embase, Scopus, ProQuest, and Cochrane Central to February 2020. Pairs of reviewers independently identified eligible trials, extracted data, and assessed the risk of bias. Eligible trials compared the prophylactic effects of any oral or intravenous medications or intracranial drug-eluting implants to one another or placebo or standard of care in adult hospitalized patients with confirmed aneurysmal subarachnoid hemorrhage. We used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to assess the certainty of the evidence.

RESULTS

We included 53 trials enrolling 10 415 patients. Nimodipine likely reduces all-cause mortality compared to placebo (odds ratio [OR],0.73 [95% CI, 0.53-1.00]; moderate certainty; absolute risk reduction (ARR), -3.35%). Nimodipine (OR, 1.46 [95% CI, 1.07-1.99]; high certainty; absolute risk increase, 8.25%) and cilostazol (OR, 3.73 [95% CI, 1.14-12.18]; moderate certainty; absolute risk increase, 23.15%) were the most effective treatments in improving disability at the longest follow-up. Compared to placebo, clazosentan (10 mg/kg; OR, 0.39 [95% CI, 0.22-0.68]; high certainty; ARR, -16.65%), nicardipine (OR, 0.48 [95% CI, 0.24-0.94]; moderate certainty; ARR, -13.70%), fasudil (OR, 0.55 [95% CI, 0.31-0.98]; moderate certainty; ARR, -11.54%), and magnesium (OR, 0.66 [95% CI, 0.46-0.94]; high certainty; ARR, -8.37%) proved most effective in reducing the likelihood of delayed cerebral ischemia.

CONCLUSIONS

Nimodipine and cilostazol are likely the most effective treatments in preventing morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage. Clazosentan, nicardipine, fasudil, and magnesium showed beneficial effects on delayed cerebral ischemia and vasospasm but they were not found to reduce mortality or disability. Future trials are warranted to elaborately investigate the prophylactic effects of medications that may improve mortality and long-term functional outcomes, such as cilostazol and clazosentan.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42019122183.

Erythropoietin and derivatives: Potential beneficial effects on the brain

Erythropoietin (Epo), the main erythropoiesis-stimulating factor widely prescribed to overcome anemia, is also known nowadays for its cytoprotective action on non-hematopoietic tissues. In this context, Epo showed not only its ability to cross the blood-brain barrier, but also its expression in the brain of mammals. In clinical trials, recombinant Epo treatment has been shown to stimulate neurogenesis; improve cognition; and activate antiapoptotic, antioxidant, and anti-inflammatory signaling pathways. These mechanisms, proposed to characterize a neuroprotective property, opened new perspectives on the Epo pharmacological potencies. However, many questions arise about a possible physiological role of Epo in the central nervous system (CNS) and the factors or environmental conditions that induce its expression. Although Epo may be considered a strong candidate to be used against neuronal damage, long-term treatments, particularly when high Epo doses are needed, may induce thromboembolic complications associated with increases in hematocrit and blood viscosity. To avoid these adverse effects, different Epo analogs without erythropoietic activity but maintaining neuroprotection ability are currently being investigated. Carbamylated erythropoietin, as well as alternative molecules like Epo fusion proteins and partial peptides of Epo, seems to match this profile. This review will focus on the discussion of experimental evidence reported in recent years linking erythropoietin and CNS function through investigations aimed at finding benefits in the treatment of neurodegenerative diseases. In addition, it will review the proposed mechanisms for novel derivatives which may clarify and, eventually, improve the neuroprotective action of Epo.

Involvement of Microglia in the Pathophysiology of Intracranial Aneurysms and Vascular Malformations-A Short Overview

Aneurysms and vascular malformations of the brain represent an important source of intracranial hemorrhage and subsequent mortality and morbidity. We are only beginning to discern the involvement of microglia, the resident immune cell of the central nervous system, in these pathologies and their outcomes. Recent evidence suggests that activated proinflammatory microglia are implicated in the expansion of brain injury following subarachnoid hemorrhage (SAH) in both the acute and chronic phases, being also a main actor in vasospasm, considerably the most severe complication of SAH. On the other hand, anti-inflammatory microglia may be involved in the resolution of cerebral injury and hemorrhage. These immune cells have also been observed in high numbers in brain arteriovenous malformations (bAVM) and cerebral cavernomas (CCM), although their roles in these lesions are currently incompletely ascertained. The following review aims to shed a light on the most significant findings related to microglia and their roles in intracranial aneurysms and vascular malformations, as well as possibly establish the course for future research.

Therapeutic Potential of Heme Oxygenase-1 in Aneurysmal Diseases

Abdominal aortic aneurysm (AAA) and intracranial aneurysm (IA) are serious arterial diseases in the aorta and brain, respectively. AAA and IA are associated with old age in males and females, respectively, and if rupture occurs, they carry high morbidity and mortality. Aneurysmal subarachnoid hemorrhage (SAH) due to IA rupture has a high rate of complication and fatality. Despite these severe clinical outcomes, preventing or treating these devastating diseases remains an unmet medical need. Inflammation and oxidative stress are shared pathologies of these vascular diseases. Therefore, therapeutic strategies have focused on reducing inflammation and reactive oxygen species levels. Interestingly, in response to cellular stress, the inducible heme oxygenase-1 (HO-1) is highly upregulated and protects against tissue injury. HO-1 degrades the prooxidant heme and generates molecules with antioxidative and anti-inflammatory properties, resulting in decreased oxidative stress and inflammation. Therefore, increasing HO-1 activity is an attractive option for therapy. Several HO-1 inducers have been identified and tested in animal models for preventing or alleviating AAA, IA, and SAH. However, clinical trials have shown conflicting results. Further research and the development of highly selective HO-1 regulators may be needed to prevent the initiation and progression of AAA, IA, or SAH.

Aneurysmal Subarachnoid Hemorrhage: the Last Decade

Aneurysmal subarachnoid hemorrhage (SAH) affects six to nine people per 100,000 per year, has a 35% mortality, and leaves many with lasting disabilities, often related to cognitive dysfunction. Clinical decision rules and more sensitive computed tomography (CT) have made the diagnosis of SAH easier, but physicians must maintain a high index of suspicion. The management of these patients is based on a limited number of randomized clinical trials (RCTs). Early repair of the ruptured aneurysm by endovascular coiling or neurosurgical clipping is essential, and coiling is superior to clipping in cases amenable to both treatments. Aneurysm repair prevents rebleeding, leaving the most important prognostic factors for outcome early brain injury from the hemorrhage, which is reflected in the neurologic condition of the patient, and delayed cerebral ischemia (DCI). Observational studies suggest outcomes are better when patients are managed in specialized neurologic intensive care units with inter- or multidisciplinary clinical groups. Medical management aims to minimize early brain injury, cerebral edema, hydrocephalus, increased intracranial pressure (ICP), and medical complications. Management then focuses on preventing, detecting, and treating DCI. Nimodipine is the only pharmacologic treatment that is approved for SAH in most countries, as no other intervention has demonstrated efficacy. In fact, much of SAH management is derived from studies in other patient populations. Therefore, further study of complications, including DCI and other medical complications, is needed to optimize outcomes for this fragile patient population.

Lessons from the CONSCIOUS-1 Study

After years of research on treatment of aneurysmal subarachnoid hemorrhage (aSAH), including randomized clinical trials, few treatments have been shown to be efficacious. Nevertheless, reductions in morbidity and mortality have occurred over the last decades. Reasons for the improved outcomes remain unclear. One randomized clinical trial that has been examined in detail with these questions in mind is Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1). This was a phase-2 trial testing the effect of clazosentan on angiographic vasospasm (aVSP) in patients with aSAH. Clazosentan decreased moderate to severe aVSP. There was no statistically significant effect on the extended Glasgow outcome score (GOS), although the study was not powered for this endpoint. Data from the approximately 400 patients in the study were detailed, rigorously collected and documented and were generously made available to one investigator. Post-hoc analyses were conducted which have expanded our knowledge of the management of aSAH. We review those analyses here.

Prioritization and Timing of Outcomes and Endpoints After Aneurysmal Subarachnoid Hemorrhage in Clinical Trials and Observational Studies: Proposal of a Multidisciplinary Research Group

INTRODUCTION

In studies on aneurysmal subarachnoid hemorrhage (SAH), substantial variability exists in the use and timing of outcomes and endpoints, which complicates interpretation and comparison of results between studies. The aim of the National Institute of Health/National Institute of Neurological Disorders and Stroke/National Library of Medicine Unruptured Intracranial Aneurysm (UIA) and SAH common data elements (CDE) Project was to provide a common structure for future UIA and SAH research.

METHODS

This article summarizes the recommendations of the UIA and SAH CDE Outcomes and Endpoints subgroup, which consisted of an international and multidisciplinary ad hoc panel of experts in clinical outcomes after SAH. Consensus recommendations were developed by review of previously published CDEs for other neurological diseases and the SAH literature. Recommendations for CDEs were classified by priority into "Core," "Supplemental-Highly Recommended," "Supplemental," and "Exploratory."

RESULTS

The subgroup identified over 50 outcomes measures and template case report forms (CRFs) to be included as part of the UIA and SAH CDE recommendations. None was classified as "Core". The modified Rankin Scale score and Montreal Cognitive Assessment were considered the preferred outcomes and classified as Supplemental-Highly Recommended. Death, Glasgow Outcome Scale score, and Glasgow Outcome Scale-extended were classified as Supplemental. All other outcome measures were categorized as "Exploratory". We propose outcome assessment at 3 months and at 12 months for studies interested in long-term outcomes. We give recommendations for standardized dichotomization.

CONCLUSION

The recommended outcome measures and CRFs have been distilled from a broad pool of potentially useful CDEs, scales, instruments, and endpoints. The adherence to these recommendations will facilitate the comparison of results across studies and meta-analyses of individual patient data.

Recent Advances in Stem Cell Research in Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke with significant morbidity and mortality, and it often leads to poor clinical outcome. Although great efforts have been made toward animal and clinical studies, optimal therapy of SAH remains a challenge for scientists and clinicians. Increasing evidence suggests that stem-cell-based therapies may provide innovative approaches for treatment of SAH-related disability. In this review, we summarized the recent advances in stem cell research in SAH. Neuroregeneration after SAH could be conducted by the activation of endogenous neural stem cells (NSCs), transplantation of external stem cells, or reprogramming non-neuronal cell to neurons. The potential mechanism and signaling pathways, as well as the efficiency and safety of these stem cell treatments, were discussed in detail. Although lots of challenges remain for translating the laboratory findings and technologies into clinical therapies, these research studies provided the foundation and guidance for using different resources of stem cells as a brain repair strategy after SAH.

Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic "triple-H" therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.

Early Brain Injury After Poor-Grade Subarachnoid Hemorrhage

PURPOSE OF REVIEW

Over the last years, the focus of clinical and animal research in subarachnoid hemorrhage (SAH) shifted towards the early phase after the bleeding based on the association of the early injury pattern (first 72 h) with secondary complications and poor outcome. This phase is commonly referenced as early brain injury (EBI). In this clinical review, we intended to overview commonly used definitions of EBI, underlying mechanisms, and potential treatment implications.

RECENT FINDINGS

We found a large heterogeneity in the definition used for EBI comprising clinical symptoms, neuroimaging parameters, and advanced neuromonitoring techniques. Although specific treatments are currently not available, therapeutic interventions are aimed at ameliorating EBI by improving the energy/supply mismatch in the early phase after SAH. Future research integrating brain-derived biomarkers is warranted to improve our pathophysiologic understanding of EBI in order to ameliorate early injury patterns and improve patients' outcomes.

Neuroprotective Role of the Nrf2 Pathway in Subarachnoid Haemorrhage and Its Therapeutic Potential

The mechanisms underlying poor outcome following subarachnoid haemorrhage (SAH) are complex and multifactorial. They include early brain injury, spreading depolarisation, inflammation, oxidative stress, macroscopic cerebral vasospasm, and microcirculatory disturbances. Nrf2 is a global promoter of the antioxidant and anti-inflammatory response and has potential protective effects against all of these mechanisms. It has been shown to be upregulated after SAH, and Nrf2 knockout animals have poorer functional and behavioural outcomes after SAH. There are many agents known to activate the Nrf2 pathway. Of these, the actions of sulforaphane, curcumin, astaxanthin, lycopene, tert-butylhydroquinone, dimethyl fumarate, melatonin, and erythropoietin have been studied in SAH models. This review details the different mechanisms of injury after SAH including the contribution of haemoglobin (Hb) and its breakdown products. It then summarises the evidence that the Nrf2 pathway is active and protective after SAH and finally examines the evidence supporting Nrf2 upregulation as a therapy after SAH.

Angioneurins - Key regulators of blood-brain barrier integrity during hypoxic and ischemic brain injury

The loss of blood-brain barrier (BBB) integrity leading to vasogenic edema and brain swelling is a common feature of hypoxic/ischemic brain diseases such as stroke, but is also central to the etiology of other CNS disorders. In the past decades, numerous proteins, belonging to the family of angioneurins, have gained increasing attention as potential therapeutic targets for ischemic stroke, but also other CNS diseases attributed to BBB dysfunction. Angioneurins encompass mediators that affect both neuronal and vascular function. Recently, increasing evidence has been accumulated that certain angioneurins critically determine disease progression and outcome in stroke among others through multifaceted effects on the compromised BBB. Here, we will give a concise overview about the family of angioneurins. We further describe the most important cellular and molecular components that contribute to structural integrity and low permeability of the BBB under steady-state conditions. We then discuss BBB alterations in ischemic stroke, and highlight underlying cellular and molecular mechanisms. For the most prominent angioneurin family members including vascular endothelial growth factors, angiopoietins, platelet-derived growth factors and erythropoietin, we will summarize current scientific literature from experimental studies in animal models, and if available from clinical trials, on the following points: (i) spatiotemporal expression of these factors in the healthy and hypoxic/ischemic CNS, (ii) impact of loss- or gain-of-function during cerebral hypoxia/ischemia for BBB integrity and beyond, and (iii) potential underlying molecular mechanisms. Moreover, we will highlight novel therapeutic strategies based on the activation of endogenous angioneurins that might improve BBB dysfuntion during ischemic stroke.

Neurotherapeutic potential of erythropoietin after ischemic injury of the central nervous system

Erythropoietin (EPO) is one of the most successful biopharmaceuticals in history and is used for treating anemia of different origins. However, it became clear that EPO could also work in a neuroprotective, antiapoptotic, antioxidative, angiogenetic and neurotropic way. It causes stimulation of cells to delay cell apoptosis, especially in the central nervous system. In rodent models of focal cerebral ischemia, EPO showed an impressive reduction of infarct size by 30% and improvement of neurobehavioral outcome by nearly 40%. A large animal model dealing with ischemia and reperfusion of the spinal cord showed that EPO could reduce the risk of spinal cord injury significantly. In addition, some clinical studies tested whether EPO works in real live clinical settings. One of the most promising studies showed the innocuousness and improvements in follow-up, outcome scales and in infarct size, of EPO-use in humans suffering from ischemic stroke. Another study ended unfortunately in a negative outcome and an increased overall death rate in the EPO group. The most possible reason was the involvement of patients undergoing simultaneously systemic thrombolysis with recombinant tissue plasminogen activator. An experimental study on rats demonstrated that administration of EPO might exacerbate tissue plasminogen activator-induced brain hemorrhage without reducing the ischemic brain damage. This case shows clearly how useful animal models can be to check negative side effects of a treatment before going into clinical trials. Other groups looked in human trials at the effects of EPO on the outcome after ischemic stroke, relation to circulating endothelial progenitor cells, aneurysmal subarachnoid hemorrhage, traumatic brain injury, hemoglobin transfusion thresholds and elective first-time coronary artery bypass surgery. Most of the results were positive, but are based mostly on small group sizes. However, some of the most neglected facts when focusing on experimental setups of ischemia of the central nervous system are issues like age and comorbidities. It might be extremely worthy to consider these points for future projects, because EPO might influence all these factors.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Reduction of inflammation after administration of interleukin-1 receptor antagonist following aneurysmal subarachnoid hemorrhage: results of the Subcutaneous Interleukin-1Ra in SAH (SCIL-SAH) study

OBJECTIVE Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating cerebrovascular event with long-term morbidity and mortality. Patients who survive the initial bleeding are likely to suffer further early brain injury arising from a plethora of pathological processes. These may result in a worsening of outcome or death in approximately 25% of patients and may contribute to longer-term cognitive dysfunction in survivors. Inflammation, mediated by the cytokine interleukin-1 (IL-1), is an important contributor to cerebral ischemia after diverse forms of brain injury, including aSAH. Its effects are attenuated by its naturally occurring antagonist, IL-1 receptor antagonist (IL-1Ra [anakinra]). The authors hypothesized that administration of additional subcutaneous IL-1Ra would reduce inflammation and associated plasma markers associated with poor outcome following aSAH. METHODS This was a randomized, open-label, single-blinded study of 100 mg subcutaneous IL-1Ra, administered twice daily in patients with aSAH, starting within 3 days of ictus and continuing until 21 days postictus or discharge from the neurosurgical center, whichever was earlier. Blood samples were taken at admission (baseline) and at Days 3-8, 14, and 21 postictus for measurement of inflammatory markers. The primary outcome was difference in plasma IL-6 measured as area under the curve between Days 3 and 8, corrected for baseline value. Secondary outcome measures included similar area under the curve analyses for other inflammatory markers, plasma pharmacokinetics for IL-1Ra, and clinical outcome at 6 months. RESULTS Interleukin-1Ra significantly reduced levels of IL-6 and C-reactive protein (p < 0.001). Fibrinogen levels were also reduced in the active arm of the study (p < 0.002). Subcutaneous IL-1Ra was safe, well tolerated, and had a predictable plasma pharmacokinetic profile. Although the study was not powered to investigate clinical effect, scores of the Glasgow Outcome Scale-extended at 6 months were better in the active group; however, this outcome did not reach statistical significance. CONCLUSIONS Subcutaneous IL-1Ra is safe and well tolerated in aSAH. It is effective in reducing peripheral inflammation. These data support a Phase III study investigating the effect of IL-1Ra on outcome following aSAH. Clinical trial registration no.: EudraCT: 2011-001855-35 ( www.clinicaltrialsregister.eu ).

The Role of Thromboinflammation in Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is a major determinant of patient outcome following aneurysmal subarachnoid hemorrhage. Although the exact mechanisms leading to DCI are not fully known, inflammation, cerebral vasospasm, and microthrombi may all function together to mediate the onset of DCI. Indeed, inflammation is tightly linked with activation of coagulation and microthrombi formation. Thromboinflammation is the intersection at which inflammation and thrombosis regulate one another in a feedforward manner, potentiating the formation of thrombi and pro-inflammatory signaling. In this review, we will explore the role(s) of inflammation and microthrombi in subarachnoid hemorrhage (SAH) pathophysiology and DCI, and discuss the potential of targeting thromboinflammation to prevent DCI after SAH.

The Effects of Red Blood Cell Transfusion on Functional Outcome after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The optimal red blood cell transfusion (RBCT) trigger for patients with aneurysmal subarachnoid hemorrhage (SAH) is unknown. In patients with cerebral vasospasm, anemia may increase susceptibility to ischemic injury; conversely, RBCT may worsen outcome given known deleterious effects.

OBJECTIVE

To examine the association between RBCT, delayed cerebral ischemia (DCI), vasospasm, and outcome after SAH.

METHODS

A total of 421 consecutive patients with SAH, admitted to a neurocritical care unit at a university-affiliated hospital and who underwent surgical occlusion of their ruptured aneurysm were retrospectively identified from a prospective observational database. Propensity score methods were used to reduce the bias associated with treatment selection.

RESULTS

Two hundred and sixty-one patients (62.0%) received an RBCT. Angiographic vasospasm (odds ratio [OR] 1.6; 95% confidence interval [CI], 1.1-2.3; P = 0.025) but not severe angiographic spasm, DCI, or delayed infarction was associated with RBCT. A total of 283 patients (67.2%) experienced a favorable outcome, defined as good or moderately disabled on the Glasgow Outcome Scale; 47 (11.2%) were severely disabled or vegetative and 91 patients (21.6%) were dead at 6-month follow-up. Among patients who survived ≥2 days, RBCT was associated with unfavorable outcome (OR, 2.6; 95% CI, 1.6-4.1). Transfusion of ≥3 units of blood was associated with an increased incidence of unfavorable outcome. Propensity analysis to control for the probability of exposure to RBCT conditional on observed covariates measured before RBCT indicates that RBCT is associated with unfavorable outcome in the absence of DCI (OR, 2.17; 95% CI, 1.56-3.01; P < 0.0001) but not when DCI is present (OR, 0.82; 95% CI, 0.35-1.92; P = 0.65).

CONCLUSIONS

Blood transfusions are associated with unfavorable outcome after SAH particularly when DCI is absent. Propensity analysis suggests that RBCT may be associated with poor outcome rather than being a marker of disease severity. However, when DCI is present, RBCT may help improve outcome.

Harms of off-label erythropoiesis-stimulating agents for critically ill people

BACKGROUND

Anaemia is a common problem experienced by critically-ill people. Treatment with erythropoiesis-stimulating agents (ESAs) has been used as a pharmacologic strategy when the blunted response of endogenous erythropoietin has been reported in critically-ill people. The use of ESAs becomes more important where adverse clinical outcomes of transfusing blood products is a limitation. However, this indication for ESAs is not licensed by regulatory authorities and is called off-label use. Recent studies concern the harm of ESAs in a critical care setting.

OBJECTIVES

To focus on harms in assessing the effects of erythropoiesis-stimulating agents (ESAs), alone or in combination, compared with placebo, no treatment or a different active treatment regimen when administered off-label to critically-ill people.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO via OvidSP, CINAHL, all evidence-based medicine (EBM) reviews including IPA and SCI-Expanded, Conference Proceedings Citation Index- Science, BIOSIS Previews and TOXLINE up to February 2017. We also searched trials registries, checked reference lists of relevant studies and tracked their citations by using SciVerse Scopus.

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) and controlled observational studies, which compared scheduled systemic administration of ESAs versus other effective interventions, placebo or no treatment in critically-ill people.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and evaluated the eligibility of retrieved records, extracted data and assessed the risks of bias and quality of the included studies. We resolved differences in opinion by consensus or by involving a third review author. We assessed the evidence using GRADE and created a 'Summary of findings' table. We used fixed-effect or random-effects models, depending on the heterogeneity between studies. We fitted three-level hierarchical Bayesian models to calculate overall treatment effect estimates.

MAIN RESULTS

Of the 27,865 records identified, 39 clinical trials and 14 observational studies, including a total of 945,240 participants, were eligible for inclusion. Five studies are awaiting classification. Overall, we found 114 adverse events in 33 studies (30 RCTs and three observational studies), and mortality was reported in 41 studies (32 RCTs and nine observational studies). Most studies were at low to moderate risk of bias for harms outcomes. However, overall harm assessment and reporting were of moderate to low quality in the RCTs, and of low quality in the observational studies. We downgraded the GRADE quality of evidence for venous thromboembolism and mortality to very low and low, respectively, because of risk of bias, high inconsistency, imprecision and limitations of study design.It is unclear whether there is an increase in the risk of any adverse events (Bayesian risk ratio (RR) 1.05, 95% confidence interval (CI) 0.93 to 1.21; 3099 participants; 9 studies; low-quality evidence) or venous thromboembolism (Bayesian RR 1.04, 95% CI 0.70 to 1.41; 18,917 participants; 18 studies; very low-quality evidence).There was a decreased risk of mortality with off-label use of ESAs in critically-ill people (Bayesian RR 0.76, 95% CI 0.61 to 0.92; 930,470 participants; 34 studies; low-quality evidence).

AUTHORS' CONCLUSIONS

Low quality of evidence suggests that off-label use of ESAs may reduce mortality in a critical care setting. There was a lack of high-quality evidence about the harm of ESAs in critically-ill people. The information for biosimilar ESAs is less conclusive. Most studies neither evaluated ESAs' harm as a primary outcome nor predefined adverse events. Any further studies of ESA should address the quality of evaluating, recording and reporting of adverse events.

The Pathophysiology of Delayed Cerebral Ischemia

Subarachnoid hemorrhage (SAH) affects 30,000 people in the Unites States alone each year. Delayed cerebral ischemia occurs days after subarachnoid hemorrhage and represents a potentially treatable cause of morbidity for approximately one-third of those who survive the initial hemorrhage. While vasospasm has been traditionally linked to the development of cerebral ischemia several days after subarachnoid hemorrhage, emerging evidence reveals that delayed cerebral ischemia is part of a much more complicated post-subarachnoid hemorrhage syndrome. The development of delayed cerebral ischemia involves early arteriolar vasospasm with microthrombosis, perfusion mismatch and neurovascular uncoupling, spreading depolarizations, and inflammatory responses that begin at the time of the hemorrhage and evolve over time, culminating in cortical infarction. Large-vessel vasospasm is likely a late contributor to ongoing injury, and effective treatment for delayed cerebral ischemia will require improved detection of critical early pathophysiologic changes as well as therapeutic options that target multiple related pathways.

Management of aneurysmal subarachnoid hemorrhage: State of the art and future perspectives

Background:

Aneurysmal subarachnoid hemorrhage (SAH) accounts for 5% of strokes and carries a poor prognosis. It affects around 6 cases per 100,000 patient years occurring at a relatively young age.

Methods:

Common risk factors are the same as for stroke, and only in a minority of the cases, genetic factors can be found. The overall mortality ranges from 32% to 67%, with 10–20% of patients with long-term dependence due to brain damage. An explosive headache is the most common reported symptom, although a wide spectrum of clinical disturbances can be the presenting symptoms. Brain computed tomography (CT) allow the diagnosis of SAH. The subsequent CT angiography (CTA) or digital subtraction angiography (DSA) can detect vascular malformations such as aneurysms. Non-aneurysmal SAH is observed in 10% of the cases. In patients surviving the initial aneurysmal bleeding, re-hemorrhage and acute hydrocephalus can affect the prognosis.

Results:

Although occlusion of an aneurysm by surgical clipping or endovascular procedure effectively prevents rebleeding, cerebral vasospasm and the resulting cerebral ischemia occurring after SAH are still responsible for the considerable morbidity and mortality related to such a pathology. A significant amount of experimental and clinical research has been conducted to find ways in preventing these complications without sound results.

Conclusions:

Even though no single pharmacological agent or treatment protocol has been identified, the main therapeutic interventions remain ineffective and limited to the manipulation of systemic blood pressure, alteration of blood volume or viscosity, and control of arterial dioxide tension.

Treatment of cerebral vasospasm following aneurysmal subarachnoid haemorrhage: a systematic review and meta-analysis

OBJECTIVES

To examine the clinical outcome of aneurysmal subarachnoid haemorrhage (aSAH) patients exposed to cerebral vasospasm (CVS)-targeted treatments in a meta-analysis and to evaluate the efficacy of intra-arterial (IA) approaches in patients with severe/refractory vasospasm.

METHODS

Randomised controlled trials, prospective and retrospective observational studies reporting clinical outcomes of aSAH patients exposed to CVS targeted treatments, published between 2006-2016 were searched using PubMed, EMBASE and the Cochrane Library. The main endpoint was the proportion of unfavourable outcomes, defined as a modified Rankin score of 3-6 at last follow-up.

RESULTS

Sixty-two studies, including 26 randomised controlled trials, were included (8,976 patients). At last follow-up 2,490 of the 8,976 patients had an unfavourable outcome, including death (random-effect weighted-average, 33.7%; 99% confidence interval [CI], 28.1-39.7%; Q value, 806.0; I ² = 92.7%). The RR of unfavourable outcome was lower in patients treated with Cilostazol (RR = 0.46; 95% CI, 0.25-0.85; P = 0.001; Q value, 1.5; I ² = 0); and in refractory CVS patients treated by IA intervention (RR = 0.68; 95% CI, 0.57-0.80; P < 0.0001; number needed to treat with IA intervention, 6.2; 95% CI, 4.3-11.2) when compared with the best available medical treatment.

CONCLUSIONS

Endovascular treatment may improve the outcome of patients with severe-refractory vasospasm. Further studies are needed to confirm this result.

KEY POINTS

• 33.7% of patients with cerebral Vasospasm following aneurysmal subarachnoid-hemorrhage have an unfavorable outcome. • Refractory vasospasm patients treated using endovascular interventions have lower relative risk of unfavourable outcome. • Subarachnoid haemorrhage patients with severe vasospasm may benefit from endovascular interventions. • The relative risk of unfavourable outcome is lower in patients treated with Cilostazol.

Neuroprotective Effect of Erythropoietin on Phenylhydrazine-Induced Hemolytic Hyperbilirubinemia in Neonatal Rats

Neonatal unconjugated hyperbilirubinemia might cause severe bilirubin neurotoxicity in especially hemolytic conditions. The study aimed to elucidate the potential neuroprotective effects of erythropoietin (EPO) in hemolysis-induced hyperbilirubinemia. In newborn rats, hyperbilirubinemia secondary to hemolysis was induced by injecting with phenylhydrazine hydrochloride (PHZ) and rats were injected with either vehicle or EPO. At 54th hour of the PHZ injection, rats were decapitated. Serum levels of TNF-α, IL-1β, IL-10, brain-derived neurotrophic factor (BDNF) and S100-B and brain malondialdehyde, glutathione levels and myeloperoxidase activities were measured. TUNEL staining and NF-κB expression were evaluated. As compared to control pups, in vehicle-treated PHZ group, TNF-α and IL-1β levels, malondialdehyde level and myeloperoxidase activity were increased with concomitant decreases in IL-10 and glutathione. All EPO regimens reversed PHZ-induced alterations in IL-10, TNF-α, malondialdehyde and glutathione levels. Three-day-treatment abolished increases in myeloperoxidase activity and IL-1β levels, while BDNF and S100-B were elevated. Increased TUNEL (+) cells and NF-κB expressions in the brain of PHZ group were reduced in the 3-day-treated group. EPO exerted anti-inflammatory effects on PHZ-induced neural damage in newborn rats, while the neuroprotection was more obvious when the treatments were repeated successively. The results suggest that EPO treatment may have a therapeutic potential in supporting neuroplasticity in the hyperbilirubinemic neonates.

Management of delayed cerebral ischemia after subarachnoid hemorrhage

For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization. Prevention of DCI primarily relies on nimodipine administration and optimization of blood volume and cardiac performance. Neurological monitoring is essential for early DCI detection and intervention. Serial clinical examination combined with intermittent transcranial Doppler ultrasonography and CT angiography (with or without perfusion) is the most commonly used monitoring paradigm, and usually suffices in good grade patients. By contrast, poor grade patients (WFNS grades 4 and 5) require more advanced monitoring because stupor and coma reduce sensitivity to the effects of ischemia. Greater reliance on CT perfusion imaging, continuous electroencephalography, and invasive brain multimodality monitoring are potential strategies to improve situational awareness as it relates to detecting DCI. Pharmacologically-induced hypertension combined with volume is the established first-line therapy for DCI; a good clinical response with reversal of the presenting deficit occurs in 70 % of patients. Medically refractory DCI, defined as failure to respond adequately to these measures, should trigger step-wise escalation of rescue therapy. Level 1 rescue therapy consists of cardiac output optimization, hemoglobin optimization, and endovascular intervention, including angioplasty and intra-arterial vasodilator infusion. In highly refractory cases, level 2 rescue therapies are also considered, none of which have been validated. This review provides an overview of current state-of-the-art care for DCI management.

Predictors of Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage with Asymptomatic Angiographic Vasospasm on Admission

BACKGROUND

Risk of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) with asymptomatic angiographic vasospasm on admission is unclear in the literature. The goal of this study is to identify predictors of clinical DCI in this group of patients.

METHODS

An exploratory subgroup analysis was conducted in the SAHIT (Subarachnoid Hemorrhage International Trialists) data repository to identify predictors of clinical DCI in patients with good-grade aSAH (World Federation of Neurological Surgeons grade I and II) with angiographic vasospasm on admission. Predictors considered include age, sex, systolic blood pressure at presentation, World Federation of Neurological Surgeon grade, Fisher grade, aneurysm size and location, treatment modality, hydrocephalus requiring external ventricular drain insertion, and severity of vasospasm. The predictors were ranked based on dominance analysis with R² as fit statistics and assessed in a set of logistic regression analysis models.

RESULTS

Four data sets out of 16 studies in the SAHIT database were analyzed, with a total of 4125 patients. One hundred and ninety-one patients (4.6%) had asymptomatic angiographic vasospasm at admission. Of those, 78 patients (40.8%) developed clinical DCI. Univariate analysis showed significant associations between severe vasospasm on admission and development of clinical DCI (odds ratio, 9.5, 95% confidence interval, 2.07-43.50; P = 0.004). None of the studied predictors was associated with the development of clinical DCI on multivariate analysis.

CONCLUSIONS

Asymptomatic angiographic vasospasm in patients with good-grade aSAH on admission is uncommon. Further studies are needed to identify high-risk patients for the development of DCI in the context of asymptomatic early vasospasm.

Exploring Erythropoietin and G-CSF Combination Therapy in Chronic Stroke Patients

Erythropoietin (EPO) and granulocyte-colony stimulating factor (G-CSF) are known to have neuroprotective actions. Based on previous reports showing the synergistic effects of EPO+G-CSF combination therapy in experimental models, we investigated the safety of EPO+G-CSF combination therapy in patients with chronic stroke. In a pilot study, 3 patients were treated with EPO and G-CSF for 5 consecutive days, with follow-up on day 30. In an exploratory double-blind study, 6 patients were allocated to treatment with either EPO+G-CSF or placebo. Treatment was applied once a day for 5 days per month over 3 months. Participants were followed up for 6 months. To substantiate safety, vital signs, adverse events, and hematological values were measured on days 0, 5, and 30 in each cycle and on day 180. Functional outcomes were determined on day 0 and 180. In the laboratory measurements, EPO+G-CSF combination therapy significantly elevated erythropoietin, CD34⁺ hematopoietic stem cells, white blood cells, and neutrophils on day 5 of each cycle. There were no observations of serious adverse events. In the functional outcomes, the grip power of the dominant hand was increased in the EPO+G-CSF treatment group. In conclusion, this exploratory study suggests a novel strategy of EPO+G-CSF combination therapy for stroke patients.

The critical care management of poor-grade subarachnoid haemorrhage

Aneurysmal subarachnoid haemorrhage is a neurological syndrome with complex systemic complications. The rupture of an intracranial aneurysm leads to the acute extravasation of arterial blood under high pressure into the subarachnoid space and often into the brain parenchyma and ventricles. The haemorrhage triggers a cascade of complex events, which ultimately can result in early brain injury, delayed cerebral ischaemia, and systemic complications. Although patients with poor-grade subarachnoid haemorrhage (World Federation of Neurosurgical Societies 4 and 5) are at higher risk of early brain injury, delayed cerebral ischaemia, and systemic complications, the early and aggressive treatment of this patient population has decreased overall mortality from more than 50% to 35% in the last four decades. These management strategies include (1) transfer to a high-volume centre, (2) neurological and systemic support in a dedicated neurological intensive care unit, (3) early aneurysm repair, (4) use of multimodal neuromonitoring, (5) control of intracranial pressure and the optimisation of cerebral oxygen delivery, (6) prevention and treatment of medical complications, and (7) prevention, monitoring, and aggressive treatment of delayed cerebral ischaemia. The aim of this article is to provide a summary of critical care management strategies applied to the subarachnoid haemorrhage population, especially for patients in poor neurological condition, on the basis of the modern concepts of early brain injury and delayed cerebral ischaemia.

Erythropoietin for the Treatment of Subarachnoid Hemorrhage: A Feasible Ingredient for a Successful Medical Recipe

Subarachnoid hemorrhage (SAH) following aneurysm bleeding accounts for 6% to 8% of all cerebrovascular accidents. Although an aneurysm can be effectively managed by surgery or endovascular therapy, delayed cerebral ischemia is diagnosed in a high percentage of patients resulting in significant morbidity and mortality. Cerebral vasospasm occurs in more than half of all patients after aneurysm rupture and is recognized as the leading cause of delayed cerebral ischemia after SAH. Hemodynamic strategies and endovascular procedures may be considered for the treatment of cerebral vasospasm. In recent years, the mechanisms contributing to the development of vasospasm, abnormal reactivity of cerebral arteries and cerebral ischemia following SAH, have been investigated intensively. A number of pathological processes have been identified in the pathogenesis of vasospasm, including endothelial injury, smooth muscle cell contraction from spasmogenic substances produced by the subarachnoid blood clots, changes in vascular responsiveness and inflammatory response of the vascular endothelium. To date, the current therapeutic interventions remain ineffective as they are limited to the manipulation of systemic blood pressure, variation of blood volume and viscosity and control of arterial carbon dioxide tension. In this scenario, the hormone erythropoietin (EPO) has been found to exert neuroprotective action during experimental SAH when its recombinant form (rHuEPO) is administered systemically. However, recent translation of experimental data into clinical trials has suggested an unclear role of recombinant human EPO in the setting of SAH. In this context, the aim of the current review is to present current evidence on the potential role of EPO in cerebrovascular dysfunction following aneurysmal subarachnoid hemorrhage.

The evidence for a role of vasospasm in the pathogenesis of cerebral malaria

Due to delay in treatment, cerebral malaria (CM) remains a significant complication of Plasmodium falciparum infection and is a common cause of death from malaria. In addition, more than 10 % of children surviving CM have neurological and long-term cognitive deficits. Understanding the pathogenesis of CM enables design of supportive treatment, reducing neurological morbidity and mortality. Vaso-occlusion and brain swelling appear to be leading to clinical features, neuronal damage and death in CM. It is proposed that parasitized red blood cells (pRBC), due to cytoadhesion to the endothelium and vasospasm induced by reduced bioavailability of nitric oxide, are causes. Stasis of blood flow and accumulation of pRBC may allow, after schizont rupture, for high concentration of products of haemolysis to accumulate, which leads to localized nitric oxide depletion, inducing adhesion molecules and cerebral vasospasm. Features consistent with an involvement of vasospasm are rapid reversibility of neurological symptoms, intermittently increased or absent flow in medium cerebral artery detectable on Doppler ultrasound and hemispheric reversible changes on cerebral magnetic resonance imaging in some patients. Clinical trials of treatment that can rapidly reduce cerebral vasospasm, including nitric oxide donors, inhaled nitric oxide, endothelin or calcium antagonists, or tissue plasminogen activators, are warranted.

Further understanding of cerebral autoregulation at the bedside: possible implications for future therapy

Cerebral autoregulation reflects the ability of the brain to keep the cerebral blood flow (CBF) relatively constant despite changes in cerebral perfusion pressure. It is an intrinsic neuroprotective physiological phenomenon often suggested as part of pathophysiological pathways in brain research. However, despite increasing knowledge of this phenomenon for over 50 years, harnessing cerebral autoregulation as a basis for therapy remains an elegant concept rather than a practical reality. This raises the question is it useful to measure at the bedside or is it merely a scientific curiosity that is too complex and has little pragmatic relevance. In this article, we attempt to answer this question by demonstrating how cerebral autoregulation assessment can have prognostic value, indicate pathological states, and potentially even influence therapy with the use of the 'optimal cerebral perfusion pressure' paradigm. Evidence from the literature is combined with bedside clinical examples to address the following fundamental questions about cerebral autoregulation: What is it? How do we measure it? Why is it important? Can we use it as a basis for therapy?

Multimodality monitoring, inflammation, and neuroregeneration in subarachnoid hemorrhage

BACKGROUND

Stroke, including subarachnoid hemorrhage (SAH), is one of the leading causes of morbidity and mortality worldwide. The mortality rate of poor-grade SAH ranges from 34% to 52%. In an attempt to improve SAH outcomes, clinical research on multimodality monitoring has been performed, as has basic science research on inflammation and neuroregeneration (which can occur due to injury-induced neurogenesis). Nevertheless, the current literature does not focus on the integrated study of these fields. Multimodality monitoring corresponds to physiological data obtained during clinical management by both noninvasive and invasive methods. Regarding inflammation and neuroregeneration, evidence suggests that, in all types of stroke, a proinflammatory phase and an anti-inflammatory phase occur consecutively; these phases affect neurogenesis, which is also influenced by other pathophysiological features of stroke, such as ischemia, seizures, and spreading depression.

OBJECTIVE

To assess whether injury-induced neurogenesis is a prognostic factor in poor-grade SAH that can be monitored and modulated.

METHODS

We propose a protocol for multimodality monitoring-guided hypothermia in poor-grade SAH in which cellular and molecular markers of inflammation and neuroregeneration can be monitored in parallel with clinical and multimodal data.

EXPECTED OUTCOMES

This study may reveal correlations between markers of inflammation and neurogenesis in blood and cerebrospinal fluid, based on clinical and multimodality monitoring parameters.

DISCUSSION

This protocol has the potential to lead to new therapies for acute, diffuse, and severe brain diseases.

The VASOGRADE: A Simple Grading Scale for Prediction of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Patients are classically at risk of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. We validated a grading scale-the VASOGRADE-for prediction of DCI.

METHODS

We used data of 3 phase II randomized clinical trials and a single hospital series to assess the relationship between the VASOGRADE and DCI. The VASOGRADE derived from previously published risk charts and consists of 3 categories: VASOGRADE-Green (modified Fisher scale 1 or 2 and World Federation of Neurosurgical Societies scale [WFNS] 1 or 2); VASOGRADE-Yellow (modified Fisher 3 or 4 and WFNS 1-3); and VASOGRADE-Red (WFNS 4 or 5, irrespective of modified Fisher grade). The relation between the VASOGRADE and DCI was assessed by logistic regression models. The predictive accuracy of the VASOGRADE was assessed by receiver operating characteristics curve and calibration plots.

RESULTS

In a cohort of 746 patients, the VASOGRADE significantly predicted DCI (P<0.001). The VASOGRADE-Yellow had a tendency for increased risk for DCI (odds ratio [OR], 1.31; 95% CI, 0.77-2.23) when compared with VASOGRADE-Green; those with VASOGRADE-Red had a 3-fold higher risk of DCI (OR, 3.19; 95% CI, 2.07-4.50). Studies were not a significant confounding factor between the VASOGRADE and DCI. The VASOGRADE had an adequate discrimination for prediction of DCI (area under the receiver operating characteristics curve=0.63) and good calibration.

CONCLUSIONS

The VASOGRADE results validated previously published risk charts in a large and diverse sample of subarachnoid hemorrhage patients, which allows DCI risk stratification on presentation after subarachnoid hemorrhage. It could help to select patients at high risk of DCI, as well as standardize treatment protocols and research studies.

Tolerability and efficacy of erythropoietin (EPO) treatment in traumatic spinal cord injury: a preliminary randomized comparative trial vs. methylprednisolone (MP)

The only available treatment of traumatic spinal cord injury (TSCI) is high-dose methylprednisolone (MP) administered acutely after injury. However, as the efficacy of MP is controversial, we assessed the superiority of erythropoietin (EPO) versus MP in improving clinical outcome of acute TSCI. Patients aged 18 to 65 years after C5-T12 injury, and grade A or B of the ASIA Impairment Scale (AIS), admitted within 8 h, hemodynamically stable, were randomized to MP according to the NASCIS III protocol or EPO iv (500 UI/kg, repeated at 24 and 48 h). Patients were assessed by an investigator blind to treatment assignment at baseline and at day 3, 7, 14, 30, 60 and 90. Primary end point: number of responders (reduction of at least one AIS grade). Secondary end points: treatment safety and the effects of drugs on a number of disability measures. Frequentistic and post hoc Bayesian analyses were performed. Eight patients were randomized to MP and 11 to EPO. Three patients (27.3 %) on EPO and no patients on MP reached the primary end point (p = 0.17). No significant differences were found for the other disability measures. No adverse events or serious adverse events were reported in both groups. The Bayesian analysis detected a 91.8 % chance of achieving higher success rates on the primary end point with EPO in the intention-to-treat population with a 95 % chance the difference between EPO and MP falling in the range (-0.10, 0.51) and a median value of 0.2. The results of Bayesian analysis favored the experimental treatment.

Aneurysmal subarachnoid hemorrhage: pathobiology, current treatment and future directions

Aneurysmal subarachnoid hemorrhage is the most devastating form of stroke. Many pathological mechanisms ensue after cerebral aneurysm rupture, including hydrocephalus, apoptosis of endothelial cells and neurons, cerebral edema, loss of blood-brain barrier, abnormal cerebral autoregulation, microthrombosis, cortical spreading depolarization and macrovascular vasospasm. Although studied extensively through experimental and clinical trials, current treatment guidelines to prevent delayed cerebral ischemia is limited to oral nimodipine, maintenance of euvolemia, induction of hypertension if ischemic signs occur and endovascular therapy for patients with continued ischemia after induced hypertension. Future investigations will involve agents targeting vasodilation, anticoagulation, inhibition of apoptosis pathways, free radical neutralization, suppression of cortical spreading depolarization and attenuation of inflammation.

Erythropoietin improves long-term neurological outcome in acute ischemic stroke patients: a randomized, prospective, placebo-controlled clinical trial

Introduction

Mortality and disability following ischemic stroke (IS) remains unacceptably high with respect to the conventional therapies. This study tested the effect of erythropoietin (EPO) on long-term neurological outcome in patients after acute IS. This study aimed to evaluate the safety and efficacy of two consecutive doses of EPO (5,000 IU/dose, subcutaneously administered at 48 hours and 72 hours after acute IS) on improving the 90-day combined endpoint of recurrent stroke or death that has been previously reported. A secondary objective was to evaluate the long-term (that is, five years) outcome of patients who received EPO.

Methods

This was a prospective, randomized, placebo-controlled trial that was conducted between October 2008 and March 2010 in a tertiary referral center. IS stroke patients who were eligible for EPO therapy were enrolled into the study.

Results

The results showed that long-term recurrent stroke and mortality did not differ between group 1 (placebo-control; n = 71) and group 2 (EPO-treated; n = 71).

Long-term Barthel index of <35 (defining a severe neurological deficit) was lower in group 2 than group 1 (P = 0.007). Multiple-stepwise logistic-regression analysis showed that EPO therapy was significantly and independently predictive of freedom from a Barthel index of <35 (P = 0.029). Long-term major adverse neurological event (MANE; defined as: death, recurrent stroke, or long-term Barthel index < 35) was lower in group 2 than group 1 (P = 0.04). Log-Rank test showed that MANE-free rate was higher in group 2 than group 1 (P = 0.031). Multiple-stepwise Cox-regression analysis showed that EPO therapy and higher Barthel Index at day 90 were independently predictive of freedom from long-term MANE (all P <0.04).

Conclusion

EPO therapy significantly improved long-term neurological outcomes in patients after IS.

Trial registration

ISRCTN71371114. Registered 10 October 2008.

Vasospasm in cerebral inflammation

All forms of cerebral inflammation as found in bacterial meningitis, cerebral malaria, brain injury, and subarachnoid haemorrhage have been associated with vasospasm of cerebral arteries and arterioles. Vasospasm has been associated with permanent neurological deficits and death in subarachnoid haemorrhage and bacterial meningitis. Increased levels of interleukin-1 may be involved in vasospasm through calcium dependent and independent activation of the myosin light chain kinase and release of the vasoconstrictor endothelin-1. Another key factor in the pathogenesis of cerebral arterial vasospasm may be the reduced bioavailability of the vasodilator nitric oxide. Therapeutic trials in vasospasm related to inflammation in subarachnoid haemorrhage in humans showed a reduction of vasospasm through calcium antagonists, endothelin receptor antagonists, statins, and plasminogen activators. Combination of therapeutic modalities addressing calcium dependent and independent vasospasm, the underlying inflammation, and depletion of nitric oxide simultaneously merit further study in all conditions with cerebral inflammation in double blind randomised placebo controlled trials. Auxiliary treatment with these agents may be able to reduce ischemic brain injury associated with neurological deficits and increased mortality.

High-dose erythropoietin for tissue protection

BACKGROUND

The discovery of potential anti-apoptotic and cytoprotective effects of recombinant human erythropoietin (rHuEPO) has led to clinical trials investigating the use of high-dose, short-term rHuEPO therapy for tissue protection in conditions such as stroke and myocardial infarction. Experimental studies have been favourable, but the clinical efficacy has yet to be validated.

MATERIALS AND METHODS

We have reviewed clinical studies regarding the use of high-dose, short-term rHuEPO therapy for tissue protection in humans with the purpose to detail the safety and efficacy of rHuEPO for this indication. A systematic literature search was performed using the PubMed/MEDLINE database for randomized, placebo-controlled clinical trials.

RESULTS

Twenty-six randomized controlled trials that enrolled 3176 patients were included. The majority of trials (20 trials including 2724 patients) reported no effect of rHuEPO therapy on measures of tissue protection. Five trials including 1025 patients reported safety concerns in the form of increased mortality or adverse event rates. No studies reported reduced mortality.

CONCLUSIONS

Evidence is sparse to support a tissue-protective benefit of rHuEPO in humans. Moreover, a number of studies indicate that short-term administration of high-dose rHuEPO is associated with an increased risk of mortality and serious adverse events. Further work is needed to elucidate the mechanisms of toxicity of rHuEPO in humans.

The pathophysiology and treatment of delayed cerebral ischaemia following subarachnoid haemorrhage

Cerebral vasospasm has traditionally been regarded as an important cause of delayed cerebral ischaemia (DCI) which occurs after aneurysmal subarachnoid haemorrhage, and often leads to cerebral infarction and poor neurological outcome. However, data from recent studies argue against a pure focus on vasospasm as the cause of delayed ischaemic complications. Findings that marked reduction in the incidence of vasospasm does not translate to a reduction in DCI, or better outcomes has intensified research into other possible mechanisms which may promote ischaemic complications. Early brain injury and cell death, blood-brain barrier disruption and initiation of an inflammatory cascade, microvascular spasm, microthrombosis, cortical spreading depolarisations and failure of cerebral autoregulation, have all been implicated in the pathophysiology of DCI. This review summarises the current knowledge about the mechanisms underlying the development of DCI. Furthermore, it aims to describe and categorise the known pharmacological treatment options with respect to the presumed mechanism of action and its role in DCI.

Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup

Despite substantial investments by government, philanthropic, and commercial sources over the past several decades, traumatic brain injury (TBI) remains an unmet medical need and a major source of disability and mortality in both developed and developing societies. The U.S. Department of Defense neurotrauma research portfolio contains more than 500 research projects funded at more than $700 million and is aimed at developing interventions that mitigate the effects of trauma to the nervous system and lead to improved quality of life outcomes. A key area of this portfolio focuses on the need for effective pharmacological approaches for treating patients with TBI and its associated symptoms. The Neurotrauma Pharmacology Workgroup was established by the U.S. Army Medical Research and Materiel Command (USAMRMC) with the overarching goal of providing a strategic research plan for developing pharmacological treatments that improve clinical outcomes after TBI. To inform this plan, the Workgroup (a) assessed the current state of the science and ongoing research and (b) identified research gaps to inform future development of research priorities for the neurotrauma research portfolio. The Workgroup identified the six most critical research priority areas in the field of pharmacological treatment for persons with TBI. The priority areas represent parallel efforts needed to advance clinical care; each requires independent effort and sufficient investment. These priority areas will help the USAMRMC and other funding agencies strategically guide their research portfolios to ensure the development of effective pharmacological approaches for treating patients with TBI.

Erythropoietin exerts cell protective effect by activating PI3K/Akt and MAPK pathways in C6 Cells

Even though erythropoietin (EPO) is a neurotropic cytokine that is recognized widely for its role in the development, maintenance, protection, and repair of the nervous system, there are few reports concerning EPO-mediated influences on the glial cells in the central nervous system. In this study, we investigated anti-inflammatory and anti-apoptotic effects of EPO on C6 glioma cells (C6 cells). Erythropoietin did not attenuate inflammatory response, such as nitrite production, iNOS gene expression, and pro-inflammatory cytokines when LPS/TNF-alpha mixture was treated. However, EPO increased C6 cell viability by exerting cell protective effect against staurosporine stimulation. Erythropoietin increased the transient Akt expression at 30 minutes and induced the gradual elevation of ERK1/2 and p38 expression as time progressed. The cell protective effect of EPO was also significantly attenuated with pretreatment of specific PI3K, pERK1/2, or pP38 inhibitor. In summary, these results suggest that EPO may exert its cell protective functions via the direct cell protective activity rather than via its anti-inflammatory effect. Moreover, the PI3K/Akt and mitogen activated protein kinase (MAPK) pathways may be responsible for cell survival against cytotoxicity.