Double-blind, randomized, vehicle-controlled study of high-dose tirilazad mesylate in women with aneurysmal subarachnoid hemorrhage. Part I. A cooperative study in Europe, Australia, New Zealand, and South Africa

Lessons Learned from Phase II and Phase III Trials Investigating Therapeutic Agents for Cerebral Ischemia Associated with Aneurysmal Subarachnoid Hemorrhage

One of the challenges in bringing new therapeutic agents (since nimodipine) in for the treatment of cerebral ischemia associated with aneurysmal subarachnoid hemorrhage (aSAH) is the incongruence in therapeutic benefit observed between phase II and subsequent phase III clinical trials. Therefore, identifying areas for improvement in the methodology and interpretation of results is necessary to increase the value of phase II trials. We performed a systematic review of phase II trials that continued into phase III trials, evaluating a therapeutic agent for the treatment of cerebral ischemia associated with aSAH. We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines for systematic reviews, and review was based on a peer-reviewed protocol (International Prospective Register of Systematic Reviews no. 222965). A total of nine phase III trials involving 7,088 patients were performed based on eight phase II trials involving 1558 patients. The following therapeutic agents were evaluated in the selected phase II and phase III trials: intravenous tirilazad, intravenous nicardipine, intravenous clazosentan, intravenous magnesium, oral statins, and intraventricular nimodipine. Shortcomings in several design elements of the phase II aSAH trials were identified that may explain the incongruence between phase II and phase III trial results. We suggest the consideration of the following strategies to improve phase II design: increased focus on the selection of surrogate markers of efficacy, selection of the optimal dose and timing of intervention, adjustment for exaggerated estimate of treatment effect in sample size calculations, use of prespecified go/no-go criteria using futility design, use of multicenter design, enrichment of the study population, use of concurrent control or placebo group, and use of innovative trial designs such as seamless phase II to III design. Modifying the design of phase II trials on the basis of lessons learned from previous phase II and phase III trial combinations is necessary to plan more effective phase III trials.

Effectiveness comparisons of drug therapies for postoperative aneurysmal subarachnoid hemorrhage patients: network meta‑analysis and systematic review

Objective

To compare the effectiveness of various drug interventions in improving the clinical outcome of postoperative patients after aneurysmal subarachnoid hemorrhage (aSAH) and assist in determining the drugs of definite curative effect in improving clinical prognosis.

Methods

Eligible Randomized Controlled Trials (RCTs) were searched in databases of PubMed, EMBASE, and Cochrane Library (inception to Sep 2020). Glasgow Outcome Scale (GOS) score, Extended Glasgow Outcome Scale (GOSE) score or modified Rankin Scale (mRS) score was used as the main outcome measurements to evaluate the efficacy of various drugs in improving the clinical outcomes of postoperative patients with aSAH. The network meta-analysis (NMA) was conducted based on a random-effects model, dichotomous variables were determined by using odds ratio (OR) with 95% confidence interval (CI), and a surface under the cumulative ranking curve (SUCRA) was generated to estimate the ranking probability of comparative effectiveness among different drug therapies.

Results

From the 493 of initial citation screening, forty-four RCTs (n = 10,626 participants) were eventually included in our analysis. Our NMA results showed that cilostazol (OR = 3.35,95%CI = 1.50,7.51) was the best intervention to improve the clinical outcome of patients (SUCRA = 87.29%, 95%CrI 0.07–0.46). Compared with the placebo group, only two drug interventions [nimodipine (OR = 1.61, 95%CI 1.01,2.57) and cilostazol (OR = 3.35, 95%CI 1.50, 7.51)] achieved significant statistical significance in improving the clinical outcome of patients.

Conclusions

Both nimodipine and cilostazol have exact curative effect to improve the outcome of postoperative patients with aSAH, and cilostazol may be the best drug to improve the outcome of patients after aSAH operation. Our study provides implications for future studies that, the combination of two or more drugs with relative safety and potential benefits (e.g., nimodipine and cilostazol) may improve the clinical outcome of patients more effectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02303-8.

Pharmacological inhibition of lipid peroxidative damage by the 21-aminosteroid U-74389G improves cortical mitochondrial function following traumatic brain injury in young adult male rats

The 21-aminosteroid ("lazaroid") U-74389G (U74), an inhibitor of lipid peroxidation (LP), was used to protect mitochondrial function following TBI in young adult male rats. The animals received a severe (2.2 mm) controlled cortical impact-TBI. U74 was administered intravenous at 15 min and 2 h post injury (hpi) followed by intraperitoneal dose at 8 hpi at the following doses (mg/kg): 0.3 (IV) + 1 (IP), 1 + 3, 3 + 10, 10 + 30. Total cortical mitochondria were isolated at 72 hpi and respiratory rates were measured. Mitochondrial 4-HNE and acrolein were evaluated as indicators of LP-mediated oxidative damage. At 72 h post-TBI injured animals had significantly lower mitochondrial respiration rates compared to sham. Administration of U74 at the 1 mg/kg dosing paradigm significantly improved mitochondrial respiration rates for States II, III, V(II) and RCR compared to vehicle-treated animals. At 72 h post-TBI injured animals administration of U74 also reduced reactive aldehydes levels compared to vehicle-treated animals. The aim of this study was to explore the hypothesis that interrupting secondary oxidative damage via acute pharmacological inhibition of LP by U74 following a CCI-TBI would provide mitochondrial neuroprotective effects in a dose-dependent manner. We found acute administration of U74 to injured rats resulted in improved mitochondrial function and lowered the levels of reactive aldehydes in the mitochondria. These results establish not only the most effective dose of U74 treatment to attenuate LP-mediated oxidative damage, but also set the foundation for further studies to explore additional neuroprotective effects following TBI.

Intrathecal Fibrinolysis for Aneurysmal Subarachnoid Hemorrhage: Evidence From Randomized Controlled Trials and Cohort Studies

Background: The role of intrathecal fibrinolysis for the treatment of patients with aneurysmal subarachnoid hemorrhage (aSAH) has been widely investigated; however, the results have been contradictory. In our study, we conducted a meta-analysis to evaluate the safety and efficacy of intrathecal (intracisternal or intraventricular) fibrinolysis for aSAH.

Methods: PubMed, Web of Science, Embase, Medline, and the Cochrane library databases were searched up to February 1, 2019. The outcomes analyzed were neurologic recovery, delayed ischemic neurologic deficit (DIND), mortality, and the incidence of chronic hydrocephalus and hemorrhage.

Results: A total of 21 studies comprising 1,373 patients were analyzed, including nine randomized controlled trials (RCTs) and 12 non-RCTs. The results showed that intracisternal fibrinolysis significantly decreased poor neurologic outcomes (RR = 0.62, 95% CI = 0.50–0.76, P < 0.001) and reduced the incidence of DIND (RR = 0.52, 95% CI = 0.41–0.65, P <0.001), chronic hydrocephalus (RR = 0.59, 95% CI = 0.42–0.82, P = 0.002) and mortality (RR = 0.58, 95% CI = 0.37, 0.93, P = 0.02). There was no significant difference in the occurrence of hemorrhage. Moreover, the results of the Egger test and Begg's funnel plot showed no evidence of publication bias.

Conclusions: Current evidence suggests that intracisternal fibrinolysis has beneficial effects on the clinical outcomes of patients with aSAH. However, further well-designed randomized trials are needed to confirm the efficacy and safety of intracisternal fibrinolysis for the treatment of aSAH.

Effect of body mass index on outcome after aneurysmal subarachnoid hemorrhage treated with clipping versus coiling

OBJECTIVE It has been suggested that increased body mass index (BMI) may confer a protective effect on patients who suffer from aneurysmal subarachnoid hemorrhage (aSAH). Whether the modality of aneurysm occlusion influences the effect of BMI on patient outcomes is not well understood. The authors aimed to compare the effect of BMI on outcomes for patients with aSAH treated with surgical clipping versus endovascular coiling. METHODS The authors retrospectively reviewed the outcomes for patients admitted to their institution for the management of aSAH treated with either clipping or coiling. BMI at the time of admission was recorded and used to assign patients to a group according to low or high BMI. Cutoff values for BMI were determined by classification and regression tree analysis. Predictors of poor functional outcome (defined as modified Rankin Scale score > 2 measured ≥ 90 days after the ictus) and posttreatment cerebral hypodensities detected during admission were then determined separately for patients treated with clipping or coiling using stepwise multivariate logistic regression analysis. RESULTS Of the 469 patients admitted to the authors' institution with aSAH who met the study's inclusion criteria, 144 were treated with clipping and 325 were treated with coiling. In the clipping group, the frequency of poor functional outcome was higher in patients with BMI ≥ 32.3 kg/m² (47.6% vs 19.0%; p = 0.007). In contrast, in the coiling group, patients with BMI ≥ 32.3 kg/m² had a lower frequency of poor functional outcome at ≥ 90 days (5.8% vs 30.9%; p < 0.001). On multivariate analysis, high BMI was independently associated with an increased (OR 3.92, 95% CI 1.20-13.41; p = 0.024) and decreased (OR 0.13, 95% CI 0.03-0.40; p < 0.001) likelihood of poor functional outcome for patients treated with clipping and coiling, respectively. For patients in the surgical group, BMI ≥ 28.4 kg/m² was independently associated with incidence of cerebral hypodensities during admission (OR 2.44, 95% CI 1.16-5.25; p = 0.018) on multivariate analysis. For patients treated with coiling, BMI ≥ 33.2 kg/m² was independently associated with reduced odds of hypodensities (OR 0.45, 95% CI 0.21-0.89; p = 0.021). CONCLUSIONS The results of this study suggest that BMI may differentially affect functional outcomes after aSAH, depending on treatment modality. These findings may aid in treatment selection for patients with aSAH.

Neurosurgeon academic impact is associated with clinical outcomes after clipping of ruptured intracranial aneurysms

BACKGROUND

Surgeon-dependent factors such as experience and volume are associated with patient outcomes. However, it is unknown whether a surgeon's research productivity could be related to outcomes. The main aim of this study is to investigate the association between the surgeon's academic productivity and clinical outcomes following neurosurgical clipping of ruptured aneurysms.

METHODS

We performed a post-hoc analysis of 3567 patients who underwent clipping of ruptured intracranial aneurysms in the randomized trials of tirilazad mesylate from 1990 to 1997. These trials included 162 centers and 156 surgeons from 21 countries. Primary and secondary outcomes were: Glasgow outcome scale score and mortality, respectively. Total publications, H-index, and graduate degrees were used as academic indicators for each surgeon. The association between outcomes and academic factors were assessed using a hierarchical logistic regression analysis, adjusting for patient covariates.

RESULTS

Academic profiles were available for 147 surgeons, treating a total of 3307 patients. Most surgeons were from the USA (62, 42%), Canada (18, 12%), and Germany (15, 10%). On univariate analysis, the H-index correlated with better functional outcomes and lower mortality rates. In the multivariate model, patients under the care of surgeons with higher H-indices demonstrated improved neurological outcomes (p = 0.01) compared to surgeons with lower H-indices, without any significant difference in mortality. None of the other academic indicators were significantly associated with outcomes.

CONCLUSION

Although prognostication following surgery for ruptured intracranial aneurysms primarily depends on clinical and radiological factors, the academic impact of the operating neurosurgeon may explain some heterogeneity in surgical outcomes.

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.

Clinical outcome prediction in aneurysmal subarachnoid hemorrhage - Alterations in brain-body interface

Background:

Brain–body associations are essential in influencing outcome in patients with ruptured brain aneurysms. Thus far, there is scarce literature on such important relationships.

Methods:

The multicenter Tirilazad database (3551 patients) was used to create this clinical outcome prediction model in order to elucidate significant brain–body associations. Traditional binary logistic regression models were used.

Results:

Binary logistic regression main effects model included four statistically significant single prognostic variables, namely, neurological grade, age, stroke, and time to surgery. Logistic regression models demonstrated the significance of hypertension and liver disease in development of brain swelling, as well as the negative consequences of seizures in patients with a history of myocardial infarction and post-admission fever worsening neurological outcome.

Conclusions:

Using the aforementioned results generated from binary logistic regression models, we can identify potential patients who are in the high risk group of neurological deterioration. Specific therapies can be tailored to prevent these detriments, including treatment of hypertension, seizures, early detection and treatment of myocardial infarction, and prevention of hepatic encephalopathy.

Delayed ischemia after subarachnoid hemorrhage: result of vasospasm alone or a broader vasculopathy?

The term vasospasm is commonly used to describe constriction of cerebral blood vessels after subarachnoid hemorrhage which results in the restriction of blood flow and ischemia in affected portions of the brain. The pathophysiological changes that underlie vascular constriction after subarachnoid hemorrhage include changes within the vessel walls themselves, alteration of the levels of several vasoactive substances, and broader pathological conditions such as immune responses, inflammation, and oxidative damage. In this review, we summarize the current state of knowledge concerning the processes that occur in cerebral blood vessels after subarachnoid hemorrhage and how they may be involved in the development of vasospasm. We also propose that, rather than merely vasospasm, the multitude of vascular effects occurring after subarachnoid hemorrhage can be best described as a post-subarachnoid hemorrhage vasculopathy.

Nonconvulsive status epilepticus in adults - insights into the invisible

Nonconvulsive status epilepticus (NCSE) is a state of continuous or repetitive seizures without convulsions. Owing to the nonspecific symptoms and considerable morbidity and mortality associated with NCSE, clinical research has focused on early diagnosis, risk stratification and seizure termination. The subtle symptoms and the necessity for electroencephalographic confirmation of seizures result in under-diagnosis with deleterious consequences. The introduction of continuous EEG to clinical practice, and the characterization of electrographic criteria have delineated a number of NCSE types that are associated with different prognoses in several clinical settings. Epidemiological studies have uncovered risk factors for NCSE; knowledge of these factors, together with particular clinical characteristics and EEG observations, enables tailored treatment. Despite these advances, NCSE can be refractory to antiepileptic drugs, necessitating further escalation of treatment. The presumptive escalation to anaesthetics, however, has recently been questioned owing to an association with increased mortality. This Review compiles epidemiological, clinical and diagnostic aspects of NCSE, and considers current treatment options and prognosis.

Clinical characteristics and outcome of aneurysmal subarachnoid hemorrhage with intracerebral hematoma

OBJECTIVE Intracerebral hematoma (ICH) with subarachnoid hemorrhage (SAH) indicates a unique feature of intracranial aneurysm rupture since the aneurysm is in the subarachnoid space and separated from the brain by pia mater. Broad consensus is lacking regarding the concept that ultra-early treatment improves outcome. The aim of this study is to determine the associative factors for ICH, ascertain the prognostic value of ICH, and investigate how the timing of treatment relates to the outcome of SAH with concurrent ICH. METHODS The study data were pooled from the SAH International Trialists repository. Logistic regression was applied to study the associations of clinical and aneurysm characteristics with ICH. Proportional odds models and dominance analysis were applied to study the effect of ICH on 3-month outcome (Glasgow Outcome Scale) and investigate the effect of time from ictus to treatment on outcome. RESULTS Of the 5362 SAH patients analyzed, 1120 (21%) had concurrent ICH. In order of importance, neurological status, aneurysm location, aneurysm size, and patient ethnicity were significantly associated with ICH. Patients with ICH experienced poorer outcome than those without ICH (OR 1.58; 95% CI 1.37-1.82). Treatment within 6 hours of SAH was associated with poorer outcome than treatment thereafter (adjusted OR 1.67; 95% CI 1.04-2.69). Subgroup analysis with adjustment for ICH volume, location, and midline shift resulted in no association between time from ictus to treatment and outcome (OR 0.99; 95% CI 0.94-1.07). CONCLUSIONS The most important associative factor for ICH is neurological status on admission. The finding regarding the value of ultra-early treatment suggests the need to more robustly reevaluate the concept that hematoma evacuation of an ICH and repair of a ruptured aneurysm within 6 hours of ictus is the most optimal treatment path.

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.

Pharmacologic Management of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) remains a condition with suboptimal functional outcomes, especially in the young population. Pharmacotherapy has an accepted role in several aspects of the disease and an emerging role in several others. No preventive pharmacologic interventions for SAH currently exist. Antiplatelet medications as well as anticoagulation have been used to prevent thromboembolic events after endovascular coiling. However, the main focus of pharmacologic treatment of SAH is the prevention of delayed cerebral ischemia (DCI). Currently the only evidence-based medical intervention is nimodipine. Other calcium channel blockers have been evaluated without convincing efficacy. Anti-inflammatory drugs such as statins have demonstrated early potential; however, they failed to provide significant evidence for the use in preventing DCI. Similar findings have been reported for magnesium, which showed potential in experimental studies and a phase 2 trial. Clazosentane, a potent endothelin receptor antagonist, did not translate to improve functional outcomes. Various other neuroprotective agents have been used to prevent DCI; however, the results have been, at best inconclusive. The prevention of DCI and improvement in functional outcome remain the goals of pharmacotherapy after the culprit lesion has been treated in aneurysmal SAH. Therefore, further research to elucidate the exact mechanisms by which DCI is propagated is clearly needed. In this article, we review the current pharmacologic approaches that have been evaluated in SAH and highlight the areas in which further research is needed.

Cerebral Vasospasm in Critically III Patients with Aneurysmal Subarachnoid Hemorrhage: Does the Evidence Support the Ever-Growing List of Potential Pharmacotherapy Interventions?

The occurrence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is a significant event resulting in decreased cerebral blood flow and oxygen delivery. Prevention and treatment of cerebral vasospasm is vital to avert neurological damage and reduced functional outcomes. A variety of pharmacotherapy interventions for the prevention and treatment of cerebral vasospasm have been evaluated. Unfortunately, very few large randomized trials exist to date, making it difficult to make clear recommendations regarding the efficacy and safety of most pharmacologic interventions. Considerable debate exists regarding the efficacy and safety of hypervolemia, hemodilution, and hypertension (triple-H therapy), and the implementation of each component varies substantially amongst institutions. There is a new focus on euvolemic-induced hypertension as a potentially preferred mechanism of hemodynamic augmentation. Nimodipine is the one pharmacologic intervention that has demonstrated favorable effects on patient outcomes and should be routinely administered unless contraindications are present. Intravenous nicardipine may offer an alternative to oral nimodipine. The addition of high-dose magnesium or statin therapy has shown promise, but results of ongoing large prospective studies are needed before they can be routinely recommended. Tirilazad and clazosentan offer new pharmacologic mechanisms, but clinical outcome results from prospective randomized studies have largely been unfavorable. Locally administered pharmacotherapy provides a targeted approach to the treatment of cerebral vasospasm. However, the paucity of data makes it challenging to determine the most appropriate therapy and implementation strategy. Further studies are needed for most pharmacologic therapies to determine whether meaningful efficacy exists.

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.

National socioeconomic indicators are associated with outcomes after aneurysmal subarachnoid hemorrhage: a hierarchical mixed-effects analysis

OBJECT

Although heterogeneity exists in patient outcomes following subarachnoid hemorrhage (SAH) across different centers and countries, it is unclear which factors contribute to such disparities. In this study, the authors performed a post hoc analysis of a large international database to evaluate the association between a country's socioeconomic indicators and patient outcome following aneurysmal SAH.

METHODS

An analysis was performed on a database of 3552 patients enrolled in studies of tirilazad mesylate for aneurysmal SAH from 1991 to 1997, which included 162 neurosurgical centers in North and Central America, Australia, Europe, and Africa. Two primary outcomes were assessed at 3 months after SAH: mortality and Glasgow Outcome Scale (GOS) score. The association between these outcomes, nation-level socioeconomic indicators (percapita gross domestic product [GDP], population-to-neurosurgeon ratio, and health care funding model), and patientlevel covariates were assessed using a hierarchical mixed-effects logistic regression analysis.

RESULTS

Multiple previously identified patient-level covariates were significantly associated with increased mortality and worse neurological outcome, including age, intraventricular hemorrhage, and initial neurological grade. Among national-level covariates, higher per-capita GDP (p < 0.05) was associated with both reduced mortality and improved neurological outcome. A higher population-to-neurosurgeon ratio (p < 0.01), as well as fewer neurosurgical centers per population (p < 0.001), was also associated with better neurological outcome (p < 0.01). Health care funding model was not a significant predictor of either primary outcome.

CONCLUSIONS

Higher per-capita gross GDP and population-to-neurosurgeon ratio were associated with improved outcome after aneurysmal SAH. The former result may speak to the availability of resources, while the latter may be a reflection of better outcomes with centralized care. Although patient clinical and radiographic phenotypes remain the primary predictors of outcome, this study shows that national socioeconomic disparities also explain heterogeneity in outcomes following SAH.

Protective effect of external ventricular drainage on cerebral vasospasm. A retrospective study on aneurysmal SAH treated endovascularly

OBJECTIVE

Cerebral vasospasm (VS) is one of the factors that can most significantly worsen the prognosis after aneurysmal subarachnoid hemorrhage (SAH). A substantial body of evidence supports the idea that CSF diversion could prevent VS, even if this issue is still much debated. External ventricular drainage (EVD) is the recommended procedure for post-hemorrhagic hydrocephalus. In this study we analyzed whether EVD, placed for acute hydrocephalus, is effective in reducing the incidence of clinical and radiological cerebral vasospasm in patients who underwent endovascular treatment for aneurysmal SAH.

PATIENTS AND METHODS

We retrospectively studied the incidence of radiologically confirmed VS in 141 patients treated endovascularly for aneurysmal SAH: 80 underwent EVD for hydrocephalus, 61 did not undergo EVD.

RESULTS

VS occurred in 8.75% of cases (7 patients) in the first groups, while in 22.95% (14 patients) in the second group. In addition, patients not treated with EVD display a prevalence of VS in lower Fisher grades compared to the other group.

CONCLUSION

Our data indicate that CSF drainage reduces the risk of vasospasms in patients with endovascular treatment for aneurysmal SAH.

Role of oxidized LDL and lectin-like oxidized LDL receptor-1 in cerebral vasospasm after subarachnoid hemorrhage

OBJECT

Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a serious complication. Free radicals derived from subarachnoid clotting are recognized to play an important role. Oxidized low-density lipoprotein (ox-LDL) and lectin-like oxidized LDL receptor-1 (LOX-1) have been shown to be related to the pathogenesis of atherosclerosis and may increase in cerebral arteries after SAH, due to the action of free radicals derived from a subarachnoid clot. These molecules may also affect the pathogenesis of vasospasm, generating intracellular reactive oxygen species and downregulating the expression of endothelial NO synthase (eNOS). If so, apple polyphenol might be effective in the prevention of vasospasm due to an abundant content of procyanidins, which exhibit strong radical scavenging effects, and the ability to suppress ox-LDL and LOX-1. The purposes of this study were to investigate changes in levels of ox-LDL and LOX-1 after SAH and whether administering apple polyphenol can modify cerebral vasospasm.

METHODS

Forty Japanese white rabbits were assigned randomly to 4 groups: an SAH group (n = 10); a shamoperation group (n = 10), which underwent intracisternal saline injection; a low-dose polyphenol group (n = 10) with SAH and oral administration of apple polyphenol at 10 mg/kg per day from Day 0 to Day 3; and a high-dose polyphenol group (n = 10) with SAH and oral administration of apple polyphenol at 50 mg/kg per day. At Day 4, the basilar artery and brain was excised from each rabbit. The degree of cerebral vasospasm was evaluated by measuring the cross-sectional area of each basilar artery, and the expression of ox-LDL, LOX-1, and eNOS was examined for each basilar artery by immunohistochemical staining and reverse transcriptase polymerase chain reaction. In addition, neuronal apoptosis in the cerebral cortex was evaluated by TUNEL.

RESULTS

Compared with the sham group, the expression of ox-LDL and LOX-1 in the basilar arterial wall was significantly increased in the SAH group, the expression of eNOS was significantly decreased, and the cross-sectional area of basilar artery was significantly decreased. Compared with the SAH group, the cross-sectional area of basilar artery was increased in the polyphenol groups, together with the decreased expression of ox-LDL and LOX-1 and the increased expression of eNOS. In the high-dose polyphenol group, those changes were statistically significant compared with the SAH group. In the low-dose polyphenol group, those changes were smaller than in the high-dose polyphenol group. No apoptosis and no changes were seen in the cerebral cortex in all groups.

CONCLUSIONS

This is the first study suggesting that ox-LDL and LOX-1 increase due to SAH and that they may play a role in the pathogenesis of vasospasm. It is assumed that procyanidins in apple polyphenol may inhibit a vicious cycle of ox-LDL, LOX-1, and ROS in a dose-dependent manner. Apple polyphenol is a candidate for preventive treatment of cerebral vasospasm.

Controversies and evolving new mechanisms in subarachnoid hemorrhage

Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.

Medical Management of Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage: A Review of Current and Emerging Therapeutic Interventions

Cerebral vasospasm is a major source of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH). Evidence suggests a multifactorial etiology and this concept remains supported by the assortment of therapeutic modalities under investigation. The authors provide an updated review of the literature for previous and recent clinical trials evaluating medical treatments in patients with cerebral vasospasm secondary to aSAH. Currently, the strongest evidence supports use of prophylactic oral nimodipine and initiation of triple-H therapy for patients in cerebral vasospasm. Other agents presented in this report include magnesium, statins, endothelin receptor antagonists, nitric oxide promoters, free radical scavengers, thromboxane inhibitors, thrombolysis, anti-inflammatory agents and neuroprotectants. Although promising data is beginning to emerge for several treatments, few prospective randomized clinical trials are presently available. Additionally, future investigational efforts will need to resolve discrepant definitions and outcome measures for cerebral vasospasm in order to permit adequate study comparisons. Until then, definitive recommendations cannot be made regarding the safety and efficacy for each of these therapeutic strategies and medical management practices will continue to be implemented in a wide-ranging manner.

Clinical outcome prediction in aneurysmal subarachnoid hemorrhage using Bayesian neural networks with fuzzy logic inferences

OBJECTIVE

The novel clinical prediction approach of Bayesian neural networks with fuzzy logic inferences is created and applied to derive prognostic decision rules in cerebral aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

The approach of Bayesian neural networks with fuzzy logic inferences was applied to data from five trials of Tirilazad for aneurysmal subarachnoid hemorrhage (3551 patients).

RESULTS

Bayesian meta-analyses of observational studies on aSAH prognostic factors gave generalizable posterior distributions of population mean log odd ratios (ORs). Similar trends were noted in Bayesian and linear regression ORs. Significant outcome predictors include normal motor response, cerebral infarction, history of myocardial infarction, cerebral edema, history of diabetes mellitus, fever on day 8, prior subarachnoid hemorrhage, admission angiographic vasospasm, neurological grade, intraventricular hemorrhage, ruptured aneurysm size, history of hypertension, vasospasm day, age and mean arterial pressure. Heteroscedasticity was present in the nontransformed dataset. Artificial neural networks found nonlinear relationships with 11 hidden variables in 1 layer, using the multilayer perceptron model. Fuzzy logic decision rules (centroid defuzzification technique) denoted cut-off points for poor prognosis at greater than 2.5 clusters.

DISCUSSION

This aSAH prognostic system makes use of existing knowledge, recognizes unknown areas, incorporates one's clinical reasoning, and compensates for uncertainty in prognostication.

The impact of experimental preconditioning using vascular endothelial growth factor in stroke and subarachnoid hemorrhage

Vascular endothelial growth factor (VEGF) stimulating angiogenesis was shown to be a potential novel therapeutic approach for the treatment of ischemic vascular diseases. The goal of the present study was to examine whether transfection of VEGF before occurrence of major stroke (part I) and cerebral vasospasm after experimental subarachnoid hemorrhage (SAH; part II) develops neuroprotective qualities. A total of 25 (part I) and 26 (part II) brains were analyzed, respectively. In part one, a significant reduction of infarct volume in the VEGF-treated stroke animals (43% reduction, P < 0.05) could be detected. In part two, significant vasospasm was induced in all hemorrhage groups (P < 0.02). Analyzing microperfusion, a significant higher amount of perfused vessels could be detected (P < 0.01), whereas no significant effect could be detected towards macroperfusion. Histologically, no infarctions were observed in the VEGF-treated SAH group and the sham-operated group. Minor infarction in terms of vasospasm-induced small lesions could be detected in the control vector transduced group (P = 0.05) and saline-treated group (P = 0.09). The present study demonstrates the preconditioning impact of systemic intramuscular VEGF injection in animals after major stroke and induced severe vasospasm after SAH.

Clinical trials in cardiac arrest and subarachnoid hemorrhage: lessons from the past and ideas for the future

Introduction. Elevated intracranial pressure that occurs at the time of cerebral aneurysm rupture can lead to inadequate cerebral blood flow, which may mimic the brain injury cascade that occurs after cardiac arrest. Insights from clinical trials in cardiac arrest may provide direction for future early brain injury research after subarachnoid hemorrhage (SAH). Methods. A search of PubMed from 1980 to 2012 and clinicaltrials.gov was conducted to identify published and ongoing randomized clinical trials in aneurysmal SAH and cardiac arrest patients. Only English, adult, human studies with primary or secondary mortality or neurological outcomes were included. Results. A total of 142 trials (82 SAH, 60 cardiac arrest) met the review criteria (103 published, 39 ongoing). The majority of both published and ongoing SAH trials focus on delayed secondary insults after SAH (70%), while 100% of cardiac arrest trials tested interventions within the first few hours of ictus. No SAH trials addressing treatment of early brain injury were identified. Twenty-nine percent of SAH and 13% of cardiac arrest trials showed outcome benefit, though there is no overlap mechanistically. Conclusions. Clinical trials in SAH assessing acute brain injury are warranted and successful interventions identified by the cardiac arrest literature may be reasonable targets of the study.

VBP15: preclinical characterization of a novel anti-inflammatory delta 9,11 steroid

Δ9,11 modifications of glucocorticoids (21-aminosteroids) have been developed as drugs for protection against cell damage (lipid peroxidation; lazaroids) and inhibition of neovascularization (anecortave). Part of the rationale for developing these compounds has been the loss of glucocorticoid receptor binding due to the Δ9,11 modification, thus avoiding many immunosuppressive activities and deleterious side effect profiles associated with binding to glucocorticoid and mineralocorticoid receptors. We recently demonstrated that anecortave acetate and its 21-hydroxy analog (VBP1) do, in fact, show glucocorticoid and mineralocorticoid receptor binding activities, with potent translocation of the glucocorticoid receptor to the cell nucleus. We concluded that Δ9,11 steroids showed novel anti-inflammatory properties, retaining NF-κB inhibition, but losing deleterious glucocorticoid side effect profiles. Evidence for this was developed in pre-clinical trials of chronic muscle inflammation. Here, we describe a drug development program aimed at optimizing the Δ9,11 chemistry. Twenty Δ9,11 derivatives were tested in in vitro screens for NF-κB inhibition and GR translocation to the nucleus, and low cell toxicity. VBP15 was selected as the lead compound due to potent NF-κB inhibition and GR translocation similar to prednisone and dexamethasone, lack of transactivation properties, and good bioavailability. Phamacokinetics were similar to traditional glucocorticoid drugs with terminal half-life of 0.35 h (mice), 0.58 h (rats), 5.42 h (dogs), and bioavailability of 74.5% (mice), and 53.2% (dogs). Metabolic stability showed ≥80% remaining at 1 h of VBP6 and VBP15 in human, dog, and monkey liver microsomes. Solubility, permeability and plasma protein binding were within acceptable limits. VBP15 moderately induced CYP3A4 across the three human hepatocyte donors (24-42%), similar to other steroids. VBP15 is currently under development for treatment of Duchenne muscular dystrophy.

M, Murray GD, Kassell NF, Torner J, Kerr RSC, Molyneux AJ, Macdonald RL. Sliding dichotomy compared with fixed dichotomization of ordinal outcome scales in subarachnoid hemorrhage trials

Object

In randomized clinical trials of subarachnoid hemorrhage (SAH) in which the primary clinical outcomes are ordinal, it has been common practice to dichotomize the ordinal outcome scale into favorable versus unfavorable outcome. Using this strategy may increase sample sizes by reducing statistical power. Authors of the present study used SAH clinical trial data to determine if a sliding dichotomy would improve statistical power.

Methods

Available individual patient data from tirilazad (3552 patients), clazosentan (the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage trial [CONSCIOUS-1], 413 patients), and subarachnoid aneurysm trials (the International Subarachnoid Aneurysm Trial [ISAT], 2089 patients) were analyzed. Treatment effect sizes were examined using conventional fixed dichotomy, sliding dichotomy (logical or median split methods), or proportional odds modeling. Whether sliding dichotomy affected the difference in outcomes between the several age and neurological grade groups was also evaluated.

Results

In the tirilazad data, there was no significant effect of treatment on outcome (fixed dichotomy: OR = 0.92, 95% CI 0.80–1.07; and sliding dichotomy: OR = 1.02, 95% CI 0.87–1.19). Sliding dichotomy reversed and increased the difference in outcome in favor of the placebo over clazosentan (fixed dichotomy: OR = 1.06, 95% CI 0.65–1.74; and sliding dichotomy: OR = 0.85, 95% CI 0.52–1.39). In the ISAT data, sliding dichotomy produced identical odds ratios compared with fixed dichotomy (fixed dichotomy vs sliding dichotomy, respectively: OR = 0.67, 95% CI 0.55–0.82 vs OR = 0.67, 95% CI 0.53–0.85). When considering the tirilazad and CONSCIOUS-1 groups based on age or World Federation of Neurosurgical Societies grade, no consistent effects of sliding dichotomy compared with fixed dichotomy were observed.

Conclusions

There were differences among fixed dichotomy, sliding dichotomy, and proportional odds models in the magnitude and precision of odds ratios, but these differences were not as substantial as those seen when these methods were used in other conditions such as head injury. This finding suggests the need for different outcome scales for SAH.

Angiographic vasospasm versus cerebral infarction as outcome measures after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Despite a significant reduction of angiographic vasospasm, the reduction of poor functional outcome in clinical trials on aneurysmal subarachnoid hemorrhage (SAH) remains challenging. While there is general consensus that vasospasm is associated with delayed cerebral ischemia (DCI), cerebral infarction, poor functional outcome, and mortality after SAH, causal relationships are subject to discussion. Therefore, it was the aim of our study to investigate the relationship between various outcome measures and poor functional outcome in clinical trials on pharmaceutical treatment of SAH.

METHODS

Based on data from two systematic reviews and a post hoc exploratory analysis, the relationship between the following outcome measures was investigated: (1) radiographic vasospasm, (2) DCI, (3) cerebral infarction, (4) poor functional outcome, and (5) death.

RESULTS

A reduction of angiographic vasospasm did not correlate with an improvement on dichotomous Glasgow Outcome Scale/modified Rankin Scale (GOS/mRS). In contrast, a reduction of cerebral infarction correlated with better neurological outcomes. The heterogeneous definition of DCI in previous clinical trials did not allow pooling of the data.

CONCLUSION

Future clinical trials may use cerebral infarction and functional outcome as main outcome measures to -investigate the true impact of an intervention, assuming that the intervention targets cerebral infarction and hereby improves outcome.

Vasospasm after aneurysmal subarachnoid hemorrhage: review of randomized controlled trials and meta-analyses in the literature

OBJECTIVE

Cerebral vasospasm is a major source of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). A variety of therapies have been utilized to prevent or treat vasospasm. Despite the large number of clinical trials, few randomized controlled trials (RCTs) of sufficient quality have been published. We review the RCTs and meta-analyses in the literature regarding the treatment and prevention of cerebral vasospasm following aneurysmal SAH.

METHODS

A literature search of MEDLINE, the Cochrane Controlled Trials Registry, and the National Institutes of Health/National Library of Medicine clinical trials registry was performed in January 2010 using predefined search terms. These trials were critically reviewed and categorized based on therapeutic modality.

RESULTS

Forty-four RCTs and 9 meta-analyses met the search criteria. Significant findings from these trials were analyzed. The results of this study were as follows: nimodipine demonstrated benefit following aneurysmal SAH; other calcium channel blockers, including nicardipine, do not provide unequivocal benefit; triple-H therapy, fasudil, transluminal balloon angioplasty, thrombolytics, endothelin receptor antagonists, magnesium, statins, and miscellaneous therapies such as free radical scavengers and antifibrinolytics require additional study. Tirilazad is ineffective.

CONCLUSIONS

There are many possible successful treatment options for preventing vasospasm, delayed ischemic neurologic deficits, and poor neurologic outcome following aneurysmal subarachnoid hemorrhage; however, further multicenter RCTs need to be performed to determine if there is a significant benefit from their use. Nimodipine is the only treatment that provided a significant benefit across multiple studies.

Delayed cerebral ischemia and spreading depolarization in absence of angiographic vasospasm after subarachnoid hemorrhage

It has been hypothesized that vasospasm is the prime mechanism of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Recently, it was found that clusters of spreading depolarizations (SDs) are associated with DCI. Surgical placement of nicardipine prolonged-release implants (NPRIs) was shown to strongly attenuate vasospasm. In the present study, we tested whether SDs and DCI are abolished when vasospasm is reduced or abolished by NPRIs. After aneurysm clipping, 10 NPRIs were placed next to the proximal intracranial vessels. The SDs were recorded using a subdural electrode strip. Proximal vasospasm was assessed by digital subtraction angiography (DSA). 534 SDs were recorded in 10 of 13 patients (77%). Digital subtraction angiography revealed no vasospasm in 8 of 13 patients (62%) and only mild or moderate vasospasm in the remaining. Five patients developed DCI associated with clusters of SD despite the absence of angiographic vasospasm in three of those patients. The number of SDs correlated significantly with the development of DCI. This may explain why reduction of angiographic vasospasm alone has not been sufficient to improve outcome in some clinical studies.

Lower incidence of cerebral infarction correlates with improved functional outcome after aneurysmal subarachnoid hemorrhage

Despite an undisputed association between vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH), there is debate if this association implies causality. It has been suggested that cerebral infarction is a better outcome measure than vasospasm in clinical trials and observational studies. To further investigate the relationship between infarction and outcome, we performed a systematic review and meta-analysis of all randomized, double-blind, placebo-controlled trials that studied the efficacy of pharmaceutical preventive strategies in SAH patients, and had both cerebral infarction and clinical outcome as outcome events. Effect sizes were expressed in (pooled) risk ratio (RR) estimates with corresponding 95% confidence intervals (CIs). Sensitivity analyses were performed for studies with a low risk of bias and for those who reported outcome at 3 months after SAH. Twenty-four studies including 8,552 patients were included. Pharmaceutical treatments decreased the incidence of both cerebral infarction (RR: 0.83; 95% CI: 0.74 to 0.93) and of poor functional outcome (RR: 0.92; 95% CI: 0.86 to 0.98). The sensitivity analyses did not change the results essentially. These data suggest that the previously observed association between cerebral infarction and functional outcome implies causality, and that cerebral infarction is a better outcome measure than vasospasm in clinical trials and observational studies.

Pharmacological treatment of delayed cerebral ischemia and vasospasm in subarachnoid hemorrhage

Subarachnoid hemorrhage after the rupture of a cerebral aneurysm is the cause of 6% to 8% of all cerebrovascular accidents involving 10 of 100,000 people each year. Despite effective treatment of the aneurysm, delayed cerebral ischemia (DCI) is observed in 30% of patients, with a peak on the tenth day, resulting in significant infirmity and mortality. Cerebral vasospasm occurs in more than half of all patients and is recognized as the main cause of delayed cerebral ischemia after subarachnoid hemorrhage. Its treatment comprises hemodynamic management and endovascular procedures. To date, the only drug shown to be efficacious on both the incidence of vasospasm and poor outcome is nimodipine. Given its modest effects, new pharmacological treatments are being developed to prevent and treat DCI. We review the different drugs currently being tested.

The influence of cisternal and ventricular lavage on cerebral vasospasm in patients suffering from subarachnoid hemorrhage: analysis of effectiveness

OBJECTIVE

within the last decades several clinical trials were performed to analyze the effectiveness of cisternal and ventricular lavage on cerebral vasospasm in patients suffering from subarachnoid hemorrhage. Aim of the present analysis was to review and summarize all documented clinical studies using cisternal or ventricular lavage to prevent vasospasm.

METHODS

the MEDLINE Web site ( www.pub.med.com ) was searched using the clinical query function optimized for clinical therapy. Search terms were subarachnoid hemorrhage, vasospasm, cisternal and ventricular lavage. Results were divided into cisternal and ventricular lavage therapies alone and its combination with additional treatment modalities.

RESULTS

so far the literature search revealed a total of nine clinical trials using cisternal or ventricular lavage alone in patients suffering from subarachnoid hemorrhage. The patients were treated using urokinase or recombinant tissue plasminogen activator. A metaanalysis, investigating a total of 652 included patients revealed a significant reduction of delayed neurological deficits, a significant increase of outcome and a significant decrease of mortality in the treatment group. Additional there was no difference of effectiveness or side effects using urokinase or recombinant tissue plasminogen activator. Hence, only one of these studies was based on a prospective, randomized study design. A combination of cisternal or ventricular lavage with some sort of kinetic treatment was documented in a total of three studies. All of them were designed prospectively. The combined application demonstrated reduced delayed neurological deficits, reduced vasospasm and better outcome in two studies for the treatment group. One study was stopped early due to unexpected complication.

CONCLUSIONS

In conclusion, there is strong evidence that cisternal or ventricular lavage alone and in combination with kinetic therapy lead to a reduction of cerebral vasospasm and better outcome in patients suffering from subarachnoid hemorrhage. As a consequence a prospective randomized study would be of great interest.

Middle cerebral artery occlusion model in rodents: methods and potential pitfalls

A variety of animal models have been developed for modeling ischemic stroke. The middle cerebral artery occlusion (MCAO) model has been utilized extensively, especially in rodents. While the MCAO model provides stroke researchers with an excellent platform to investigate the disease, controversial or even paradoxical results are occasionally seen in the literature utilizing this model. Various factors exert important effects on the outcome in this stroke model, including the age and sex of the animal examined. This paper discusses emerging information on the effects of age and sex on ischemic outcomes after MCAO, with an emphasis on mouse models of stroke.

Intraventricular hemorrhage volume predicts poor outcomes but not delayed ischemic neurological deficits among patients with ruptured cerebral aneurysms

BACKGROUND

Intraventricular hemorrhage (IVH) predicts worse outcomes following aneurysmal subarachnoid hemorrhage (SAH). One potential mechanism is that IVH predisposes to the development of delayed ischemic neurological deficits (DINDs). No previous studies have evaluated the association between IVH volume (in milliliters) and subsequent development of DINDs or poor outcomes.

OBJECTIVE

To assess the association between the volume of IVH and the subsequent development of DINDs, delayed cerebral infarction, death, and poor neurological outcomes, specifically among patients with concomitant SAH and IVH.

METHODS

We performed a cohort study involving 152 consecutive patients with concomitant SAH and IVH. To determine volume of IVH, we used the IVH Score, shown to correlate well with computerized volumetric assessment. To determine the relative quantity of subarachnoid blood, we applied the SAH Sum Score. Multivariate logistic regression was used to adjust for potential confounders.

RESULTS

There was no significant association between IVH volume and the development of DINDs or delayed infarction. In contrast, patients with poor neurological outcomes had significantly larger baseline IVH volume (mean, 11.8 mL vs 3.8 mL, P = .001). In the multivariate analysis, IVH volume was an independent predictor of poor outcomes (OR per mL: 1.11 [1.04-1.18]). Patients in the highest quartile for IVH volume were far more likely to progress to poor outcome compared with those in the lowest quartile (OR 4.09 [1.32-12.65]). Interobserver agreement in the determination of IVH Score was moderate to good.

CONCLUSIONS

IVH volume is an independent predictor of poor neurological outcomes, even after adjusting for the amount of subarachnoid blood. The pathophysiology of this association does not appear to involve an increased risk of DINDs or delayed infarction. Measures aimed at accelerating IVH clearance, such as intraventricular thrombolysis, merit further evaluation.

Neuroprotection in subarachnoid hemorrhage

Despite advances in aneurysm ablation and the initial management of patients presenting with aneurysmal subarachnoid hemorrhage, delayed cerebral ischemia remains a significant source of morbidity. Traditionally, delayed cerebral ischemia was thought to be a result of vasospasm of the proximal intracranial vessels, and clinical trials have relied largely on radiographic evidence of vasospasm as a surrogate for functional outcome. However, a number of trials have demonstrated a dissociation between angiographic vasospasm and outcome, and more recent data suggest that other mechanisms of injury, such as microvascular dysfunction and complex neuronal-glial interactions, may influence the development of delayed ischemic deficit after aneurysmal subarachnoid hemorrhage. Our evolving understanding of the pathophysiology of delayed cerebral ischemia may offer the opportunity to test new therapeutic strategies in this area and improve clinical trial design.

Effect of vardenafil on cerebral vasospasm following experimental subarachnoid hemorrhage in rats

We examined the effects of the phosphodiesterase 5 (PDE-5) inhibitor vardenafil on cerebral vasospasm in an experimental rat subarachnoid hemorrhage (SAH) model. Thirty-two albino Wistar rats were divided into five groups: G1, no experimental intervention; G2, administered subarachnoid physiological saline after sham surgery; G3, subjected to SAH; G4, subjected to SAH and administered low-dose (0.5 mg/kg) vardenafil treatment; and G5, subjected to SAH and administered high-dose (5 mg/kg) vardenafil treatment. For animals in G3, G4 and G5, SAH was induced by an injection of autologous non-heparinized blood into the cisterna magna. Immediately after SAH, for animals in G4 and G5, vardenafil was administered by gavage at intervals of 8 hours for 2 days. The rats were then decapitated, and basilar arteries and blood samples were taken for biochemical and histopathological examination. Malonyldialdehyde values in G2 (p = 0.004) and G3 (p = 0.002) were significantly higher than those in G1. G4 and G5 had significantly lower values than G2 and G3 (p = 0.014, G4 v. G2; p = 0.005, G4 v. G3; p = 0.005, G5 v. G2; p = 0.002, G5 v. G3). Total antioxidant capacity (TAC) values in G3 were significantly lower than those in G1 (p = 0.041). TAC values in G4 and G5 were significantly higher than those in G3 (p = 0.043). Mean luminal diameter in G3 was significantly smaller compared with G1 and G2 (p = 0.002), but larger in G4 (p = 0.002) and G5 (p = 0.001) compared with G3. Mean luminal diameter was also significantly larger in G5 than in G2 (p = 0.008) and G4 (p = 0.038). Mean wall thickness in G2 (p = 0.015) and G3 (p = 0.002) was significantly thicker compared with G1. Wall thickness was significantly thinner in G4 and G5 compared with G2 and G3 (p = 0.008, G4 v. G2; p = 0.001, G4 v. G3; p = 0.005, G5 v. G2; p = 0.001, G5 v. G3). Our results confirm that vardenafil may induce vasodilatation and provide potential benefits in SAH therapy by preventing vasospasm.

Translational research on rapid steroid actions

Translational research is a burgeoning science that shows potential to improve the transition of research from bench to bedside. This novel science explores all major aspects of preclinical and clinical issues which are relevant for the success of translational pharmaceutical or medical device/diagnostic innovations. This includes target risk assessment, biomarker evaluation and predictivity grading both for efficacy and toxicity, early human trial design adequate to guide stop/go decisions on grounds of biomarker panels, and biostatistical methods to analyze multiple readout situations and quantify risk projections. Representing a comparably novel science, rapid steroid actions have been recognized to carry potential clinical implications in various fields. Findings in this field have not yet been successfully translated into clinically relevant new medicines except for neurosteroids. A promising compound is the membrane estrogen receptor agonist STX, which may be applicable for estrogen withdrawal symptoms. Nongenomic vitamin D analogs may be useful as antiinflammatory, anticancer or diabetes preventing agents. Further the membrane thyroid receptor agonist tetrac may be useful in cancer treatment. Unfortunately lazaroids (membrane-only active glucocorticoids), which have been clinically tested as neuroprotective agents, had to be abandoned because of lacking clinical efficacy. Yet, the hierarchy of antirheumatic glucocorticoid action in regard to their clinical potency may better correlate with their membrane effects than their ability to bind to the classic glucocorticoid receptor. To improve the translational success of the rapid actions of steroids research, scientists should become familiar with major aspects of translational work and always seek for translational dimensions in their research.

Epidemiology of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a form of hemorrhagic stroke that affects up to 30,000 individuals per year in the United States. The incidence of aSAH has been shown to be associated with numerous nonmodifiable (age, gender, ethnicity, family history, aneurysm location, size) and modifiable (hypertension, body mass index, tobacco and illicit drug use) risk factors. Although early repair of ruptured aneurysms and aggressive postoperative management has improved overall outcomes, it remains a devastating disease, with mortality approaching 50% and less than 60% of survivors returning to functional independence. As treatment modalities change and the percentage of minority and elderly populations increase, it is critical to maintain an up-to-date understanding of the epidemiology of SAH.

The prognostic value of NSE and S100B from serum and cerebrospinal fluid in patients with spontaneous subarachnoid hemorrhage

Neuron-specific enolase (NSE) and S100B protein have been shown to be increased in cerebrospinal fluid (CSF) and serum of patients suffering from subarachnoid hemorrhage. This study was designed to evaluate the accuracy of NSE and S100B from CSF and serum for the prognosis of outcome and the detection of cerebral infarction, vasospasm and intracranial hypertension. In 55 patients with spontaneous subarachnoid hemorrhage and requiring external ventricular drainage the concentrations of NSE and S100B were determined daily from the serum and the CSF from admission until day 8. At ICU discharge patients' outcome was assessed by the Glasgow outcome scale and occurrence of cerebral infarction, vasospasm and intracranial hypertension were registered. Mean and peak values of each parameter for each patient were calculated. For accuracy assessment receiver operating characteristics were used. Bad outcome (Glasgow outcome scale 1 to 3) was found in 33 patients. Cerebral infarction, vasospasm, and intracranial hypertension were found in 31 (56%), 34 (62%), and 36 (65%) patients. Mean and peak values of NSE CSF (P<0.001), S100B CSF (P<0.001), and S100B serum (P<0.001) but not of NSE serum provided the ability to distinguish between patients with good and bad outcome. The accuracy of NSE CSF and S100B CSF did not differ significantly from that of S100B serum. NSE CSF (P<0.001), S100B CSF (P<0.001), and S100B serum (P<0.001) allowed the detection of cerebral infarction and intracranial hypertension. Cerebral vasospasm was detected by none of the parameters. In conclusion, NSE CSF, S100B CSF, and S100B serum provide similar prognostic values for outcome, intracranial hypertension and cerebral infarction. Significantly lower accuracy was found for NSE serum.

Glutamate receptors, neurotoxicity and neurodegeneration

Glutamate excitotoxicity is a hypothesis that states excessive glutamate causes neuronal dysfunction and degeneration. As glutamate is a major excitatory neurotransmitter in the central nervous system (CNS), the implications of glutamate excitotoxicity are many and far-reaching. Acute CNS insults such as ischaemia and traumatic brain injury have traditionally been the focus of excitotoxicity research. However, glutamate excitotoxicity has also been linked to chronic neurodegenerative disorders such as amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease and others. Despite the continued research into the mechanisms of excitotoxicity, there are currently no pharmacological interventions capable of providing significant neuroprotection in the clinical setting of brain ischaemia or injury. This review addresses the current state of excitotoxic research, focusing on the structure and physiology of glutamate receptors; molecular mechanisms underlying excitotoxic cell death pathways and their interactions with each other; the evidence for glutamate excitotoxicity in acute neurologic diseases; laboratory and clinical attempts at modulating excitotoxicity; and emerging targets for excitotoxicity research.

Tirilazad for aneurysmal subarachnoid haemorrhage

BACKGROUND

Delayed cerebral ischaemia is a significant contributor to poor outcome (death or disability) in patients with aneurysmal subarachnoid haemorrhage (SAH). Tirilazad is considered to have neuroprotective properties in animal models of acute cerebral ischaemia.

OBJECTIVES

To assess the efficacy and safety of tirilazad in patients with aneurysmal SAH.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched October 2009); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2009); MEDLINE (1966 to October 2009); EMBASE (1980 to October 2009); and the Stroke Trials Directory, the National Center for Complementary and Alternative Medicine, and the National Institute of Health Clinical Trials Database (searched October 2009). We handsearched 10 Chinese journals, searched the reference lists of relevant publications, and contacted the manufacturers of tirilazad.

SELECTION CRITERIA

Randomised trials of tirilazad started within four days of SAH onset, compared with placebo or open control in patients with aneurysmal SAH documented by angiography and computerised tomography (CT) scan or cerebrospinal fluid examination, or both.

DATA COLLECTION AND ANALYSIS

We extracted data relating to case fatality, poor outcome (death, vegetative state, or severe disability), delayed cerebral ischaemia (or symptomatic vasospasm), cerebral infarction and adverse events of treatments. We pooled the data using the Peto fixed-effect method for dichotomous data.

MAIN RESULTS

We included five double-blind, placebo-controlled trials involving 3821 patients; there was no significant heterogeneity. Oral or intravenous nimodipine was used routinely as a background treatment in both groups in all trials. There was no significant difference between the two groups at the end of follow up for the primary outcome, death (odds ratio (OR) 0.89, 95% confidence interval (CI) 0.74 to 1.06), or in poor outcome (death, vegetative state or severe disability) (OR 1.04, 95% CI 0.90 to 1.21). During the treatment period, fewer patients developed delayed cerebral ischaemia in the tirilazad group than in the control group (OR 0.80, 95% CI 0.69 to 0.93). Subgroup analyses did not demonstrate any significant difference in effects of tirilazad on clinical outcomes. Leukocytosis and prolongation of Q-T interval occurred significantly more frequently in the treatment group in only one trial evaluating tirilazad at high dose. There was no significant difference in infusion site disorders or other laboratory parameters between the two groups.

AUTHORS' CONCLUSIONS

There is no evidence that tirilazad, in addition to nimodipine, reduces mortality or improves poor outcome in patients with aneurysmal SAH.

Arterial diameters on catheter and computed tomographic angiography

BACKGROUND

The diagnosis of cerebral vasospasm is hampered by lack of an accurate, noninvasive test. Computed tomographic angiography (CTA) may be useful but the correlation between arterial diameters determined from catheter digital subtraction angiography (DSA) and CTA over a range of artery sizes would need to be determined to show this. The purpose of this study was to determine the correlation between artery diameters measured on DSA and multidetector CTA.

METHODS

Two hundred forty artery diameters were measured in DSA and CTA from 46 patients who underwent both studies within 12 hours of each other. Axial cross section, maximum intensity projection, and volume-rendered images were measured and compared by linear correlation. Two independent readers measured CTA diameters to determine interobserver variability by linear correlation. Values also were categorized and compared by χ(2) and κ statistics. Analysis was repeated with unmeasurable arteries assigned a value of 0.

RESULTS

There were significant correlations between arterial diameters measured on DSA and those from CTA measured by any method (R(2) ranging from 0.45 to 0.76, P < .0001), although there was a tendency for the slope of this relationship to be less than 1, indicating underestimation of diameter of large and overestimation of diameter of small arteries with CTA. Computed tomographic angiography diameters also correlated significantly between the 2 reviewers with higher values often when unmeasureable arteries were assigned a value of 0 (κ = 0.23-0.55, P < .0001).

CONCLUSION

Arterial diameters measured on multidetector CTA correlate well with those determined from DSA and should permit use of CTA for quantitative study of cerebral vasospasm and other conditions requiring accurate measurement of arterial diameters. The limitation of CTA remains the inability to measure some arteries due to artifact.

Effect of country or continent of treatment on outcome after aneurysmal subarachnoid hemorrhage

Object

Prognostic factors for outcome after aneurysmal subarachnoid hemorrhage (SAH) include the clinical and pathological characteristics of the patient and hemorrhage as well as some aspects of treatment. Because treatment can vary between countries and continents, the authors used a large database of patients with SAH to determine the effect of the geographic location of treatment on outcome.

Methods

Data obtained in 3567 patients who were entered into randomized trials of tirilazad between 1991 and 1997 were analyzed. Patients underwent treatment in 162 neurosurgical centers in 21 countries in North America, Europe, Africa, and Australia. The dependent variable was clinical outcome assessed 3 months after SAH with the Glasgow Outcome Scale, which was analyzed as a 5-point variable and dichotomized into favorable (good recovery or moderate disability) and unfavorable (severe disability, vegetative state, or death) outcomes. The effect of country or continent of treatment on outcome was assessed using univariate and multivariate logistic regression and proportional odds modeling before and after adjusting for numerous other factors significantly associated with outcome.

Results

The authors constructed several multivariate analysis models and demonstrated that for almost every model, country was not a significant predictor of outcome (p > 0.05). There was variation in outcome between countries, but this was mostly due to differences in other admission characteristics that influence outcome such as age, clinical grade, and subarachnoid clot thickness. Because the number of patients entered from some countries was small, countries were grouped, and the data were analyzed by continent. This grouping gave more stable estimates and created an appropriate model for both logistic and proportional odds models and again showed that continent had no significant effect on outcome.

Conclusions

Despite the variations in treatment that undoubtedly exist between countries and continents, the location of treatment had minimal effect on outcome. Outcome was influenced mostly by clinical characteristics on admission such as neurological grade, patient age, and amount of SAH.