Simvastatin for the prevention of symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage: a single-institution prospective cohort study

Intracranial Aneurysms and Lipid Metabolism Disorders: From Molecular Mechanisms to Clinical Implications

Many vascular diseases are linked to lipid metabolism disorders, which cause lipid accumulation and peroxidation in the vascular wall. These processes lead to degenerative changes in the vessel, such as phenotypic transformation of smooth muscle cells and dysfunction and apoptosis of endothelial cells. In intracranial aneurysms, the coexistence of lipid plaques is often observed, indicating localized lipid metabolism disorders. These disorders may impair the function of the vascular wall or result from it. We summarize the literature on the relationship between lipid metabolism disorders and intracranial aneurysms below.

Guidelines for the Neurocritical Care Management of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The neurointensive care management of patients with aneurysmal subarachnoid hemorrhage (aSAH) is one of the most critical components contributing to short-term and long-term patient outcomes. Previous recommendations for the medical management of aSAH comprehensively summarized the evidence based on consensus conference held in 2011. In this report, we provide updated recommendations based on appraisal of the literature using the Grading of Recommendations Assessment, Development, and Evaluation methodology.

METHODS

The Population/Intervention/Comparator/Outcome (PICO) questions relevant to the medical management of aSAH were prioritized by consensus from the panel members. The panel used a custom-designed survey instrument to prioritize clinically relevant outcomes specific to each PICO question. To be included, the study design qualifying criteria were as follows: prospective randomized controlled trials (RCTs), prospective or retrospective observational studies, case-control studies, case series with a sample larger than 20 patients, meta-analyses, restricted to human study participants. Panel members first screened titles and abstracts, and subsequently full text review of selected reports. Data were abstracted in duplicate from reports meeting inclusion criteria. Panelists used the Grading of Recommendations Assessment, Development, and Evaluation Risk of Bias tool for assessment of RCTs and the "Risk of Bias In Nonrandomized Studies - of Interventions" tool for assessment of observational studies. The summary of the evidence for each PICO was presented to the full panel, and then the panel voted on the recommendations.

RESULTS

The initial search retrieved 15,107 unique publications, and 74 were included for data abstraction. Several RCTs were conducted to test pharmacological interventions, and we found that the quality of evidence for nonpharmacological questions was consistently poor. Five PICO questions were supported by strong recommendations, one PICO question was supported by conditional recommendations, and six PICO questions did not have sufficient evidence to provide a recommendation.

CONCLUSIONS

These guidelines provide recommendations for or against interventions proven to be effective, ineffective, or harmful in the medical management of patients with aSAH based on a rigorous review of the available literature. They also serve to highlight gaps in knowledge that should guide future research priorities. Despite improvements in the outcomes of patients with aSAH over time, many important clinical questions remain unanswered.

Impacts of Statin Therapy Strategies on Incidence of Ischemic Cerebrovascular Events in Patients With Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

The exacerbation of neurological outcomes often occurs in aneurysmal subarachnoid hemorrhage (aSAH). Statins have been commonly used for aSAH; however, there is lack of evidence of the pharmacological efficacy of different dosages and types of statins.

OBJECTIVE

To apply the Bayesian network meta-analysis to analyze the optimal dosage and type of statins for the amelioration of ischemic cerebrovascular events (ICEs) in patients with aSAH.

METHODS

We developed the Bayesian network meta-analysis and systemic review to analyze the effects of statins on functional prognosis and the impacts of optimal dosage and type of statins on ICEs in patients with aSAH. The outcome variables of the analysis were the incidence of ICEs and functional prognosis.

RESULTS

A total of 2569 patients with aSAH across 14 studies were included. Analysis of 6 randomized controlled trials showed that statin use significantly improved functional prognosis in patients with aSAH (risk ratio [RR], 0.73; 95% CI, 0.55-0.97). Statins significantly reduced the incidence of ICEs (RR, 0.78; 95% CI, 0.67-0.90). Pravastatin (40 mg/d) decreased the incidence ICEs compared with placebo (RR, 0.14; 95% CI, 0.03-0.65) and was ranked the most effective, presenting with a significantly lower rate of the incidence ICEs than the worst-ranked simvastatin (40 mg/d) (RR, 0.13; 95% CI, 0.02-0.79).

CONCLUSION

Statins could significantly diminish the incidence of ICEs and enhance functional prognosis in patients with aSAH. Various types and dosages of statins show distinct efficacies.

Effect of early stellate ganglion block in cerebral vasospasm after aneurysmal subarachnoid hemorrhage (BLOCK-CVS): study protocol for a randomized controlled trial

Introduction

Stellate ganglion block has been reported to expand cerebral vessels and alleviate vasospasm after aneurysmal subarachnoid hemorrhage. However, the causal relationship between early stellate ganglion block and cerebral vasospasm prevention has not yet been established. The purpose of this study was to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment for cerebral vasospasm and delayed cerebral ischemia.

Methods/design

This is a single-center, prospective, randomized, controlled, blinded endpoint assessment superiority trial. A total of 228 patients will be randomized within 48 h of aneurysmal subarachnoid hemorrhage onset in a 1:1 ratio into two groups, one group receiving an additional e-SGB and the other group receiving only a camouflaging action before anesthesia induction in the operating room. The primary outcome is the incidence of symptomatic vasospasm within 14 days after aSAH. Further safety and efficacy parameters include the incidence of radiographic vasospasm, new cerebral infarction, postoperative delirium, and complications up to 90 days after surgery; postoperative cerebral hemodynamics; Mini-Mental State Examination score; modified Rankin scale score; and all-cause mortality up to 90 days after surgery.

Discussion

This is a randomized controlled trial to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment to reduce cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. If the results are positive, it may provide a new direction for the prevention and treatment of cerebral vasospasm and delayed cerebral ischemia.

Trial registration

The study was registered on Clincaltrials.gov on December 13, 2020 (NCT04691271).

An overview of pharmacotherapy for cerebral vasospasm and delayed cerebral ischemia after subarachnoid hemorrhage

Introduction: Survival from aneurysmal subarachnoid hemorrhage has increased in the past few decades. However, functional outcome after subarachnoid hemorrhage is still suboptimal. Delayed cerebral ischemia (DCI) is one of the major causes of morbidity.Areas covered: Mechanisms underlying vasospasm and DCI after aneurysmal subarachnoid hemorrhage and pharmacological treatment are summarized in this review.Expert opinion: Oral nimodine, an L-type dihydropyridine calcium channel blocker, is the only FDA-approved drug for the prevention and treatment of neurological deficits after aneurysmal subarachnoid hemorrhage. Fasudil, a potent Rho-kinase inhibitor, has also been shown to improve the clinical outcome and has been approved in some countries for use in patients with aneurysmal subarachnoid hemorrhage. Although other drugs, including nicardipine, cilostazol, statins, clazosentan, magnesium and heparin, have been expected to have beneficial effects on DCI, there has been no convincing evidence supporting the routine use of those drugs in patients with aneurysmal subarachnoid hemorrhage in clinical practice. Further elucidation of the mechanisms underlying DCI and the development of effective therapeutic strategies for DCI, including combination therapy, are necessary to further improve the functional outcome and mortality after subarachnoid hemorrhage.

Atorvastatin reduces cerebral vasospasm and infarction after aneurysmal subarachnoid hemorrhage in elderly Chinese adults

We explored whether acute atorvastatin treatment would improve clinical outcomes and reduce the incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage in elderly Chinese adults. Patients (60 to 90 years old) were admitted to intensive care units after surgery to clip or embolize their aneurysms. We assessed 592 patients and assigned 159 to receive atorvastatin (20 mg/day) and 158 to receive placebo once daily for up to 14 days. The primary outcome was the Glasgow outcome scale at 6 months, and secondary outcomes were cerebral vasospasm, 30-days all-cause mortality, cerebral infarction, and delayed ischemic neurological deficit. The incidence of postoperative cerebral vasospasm (39.3% vs 56%, P =0.004) and cerebral infarction (18.7% vs 27.3%, P=0.027) were significantly lower in the atorvastatin group. The study did not detect benefits in the use of atorvastatin for 6 months clinical outcome or 30-day all-cause mortality, but it suggests that atorvastatin together with nimodipine can reduce cerebral vasospasm and cerebral infarction after subarachnoid hemorrhage.

Long-acting statin for aneurysmal subarachnoid hemorrhage: A randomized, double-blind, placebo-controlled trial

Statins have pleiotropic effects that are considered beneficial in preventing cerebral vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (aSAH). Many studies using statins have been performed but failed to show remarkable effects. We hypothesized that a long-acting statin would be more effective, due to a longer half-life and stronger pleiotropic effects. Patients with aSAH were randomly assigned to a pitavastatin group (4 mg daily; n = 54) and a placebo group ( n = 54) after repair of a ruptured aneurysm. The primary efficacy end point was vasospasm-related delayed ischemic neurological deficits (DIND), and the secondary end points were cerebral vasospasm evaluated by digital subtraction angiography (DSA), vasospasm-related new cerebral infarctions, and outcome at three months. Severe cerebral vasospasms on DSA were statistically fewer in the pitavastatin group than in the placebo group (14.8% vs. 33.3%; odds ratio, 0.32; 95% confidence interval, 0.11-0.87, p = 0.042); however, the occurrence of DIND and new infarctions and outcome showed no statistically significant differences between the groups. The present study is the first to prove the definite, statin-induced amelioration of cerebral vasospasm on DSA. However, administration of any type of statin at the acute phase of aSAH is not recommended.

Dose-Dependent Effects of Statins for Patients with Aneurysmal Subarachnoid Hemorrhage: Meta-Regression Analysis

OBJECTIVE

The study uses meta-regression analysis to quantify the dose-dependent effects of statin pharmacotherapy on vasospasm, delayed ischemic neurologic deficits (DIND), and mortality in aneurysmal subarachnoid hemorrhage.

METHODS

Prospective, retrospective observational studies, and randomized controlled trials (RCTs) were retrieved by a systematic database search. Summary estimates were expressed as absolute risk (AR) for a given statin dose or control (placebo). Meta-regression using inverse variance weighting and robust variance estimation was performed to assess the effect of statin dose on transformed AR in a random effects model. Dose-dependence of predicted AR with 95% confidence interval (CI) was recovered by using Miller's Freeman-Tukey inverse.

RESULTS

The database search and study selection criteria yielded 18 studies (2594 patients) for analysis. These included 12 RCTs, 4 retrospective observational studies, and 2 prospective observational studies. Twelve studies investigated simvastatin, whereas the remaining studies investigated atorvastatin, pravastatin, or pitavastatin, with simvastatin-equivalent doses ranging from 20 to 80 mg. Meta-regression revealed dose-dependent reductions in Freeman-Tukey-transformed AR of vasospasm (slope coefficient -0.00404, 95% CI -0.00720 to -0.00087; P = 0.0321), DIND (slope coefficient -0.00316, 95% CI -0.00586 to -0.00047; P = 0.0392), and mortality (slope coefficient -0.00345, 95% CI -0.00623 to -0.00067; P = 0.0352).

CONCLUSIONS

The present meta-regression provides weak evidence for dose-dependent reductions in vasospasm, DIND and mortality associated with acute statin use after aneurysmal subarachnoid hemorrhage. However, the analysis was limited by substantial heterogeneity among individual studies. Greater dosing strategies are a potential consideration for future RCTs.

Anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage in an intensive care unit

Intracerebral hemorrhage is one of the most common types of cerebrovascular disease in humans and often causes paralysis, a vegetative state and even death. Patients with acute intracerebral hemorrhage are frequently monitored in intensive care units (ICUs). Spontaneous intracerebral hemorrhage is associated with a higher rate of mortality and morbidity than other intracephalic diseases. The expression levels of inflammatory factors have important roles in inflammatory responses indicative of changes in a patient's condition and are therefore important in the monitoring and treatment of affected patients at the ICU as well as the development of therapeutic strategies for acute cerebral hemorrhage. The present study investigated the anti-inflammatory effects of Simvastatin in patients with acute intracerebral hemorrhage at an ICU, and inflammatory factors and cellular changes were systematically analyzed. The plasma concentrations of inflammatory factors, including interleukin (IL)-4, IL-6, IL-8 and IL-10, were evaluated by ELISAs. The plasma concentrations of inflammatory cellular changes were detected by using flow cytometry. The results demonstrated that after Simvastatin treatment of patients with acute cerebral hemorrhage at the ICU, the plasma concentrations of IL-4, IL-6, IL-8 and IL-10 were downregulated compared with those in placebo-treated controls. In addition, Simvastatin treatment at the ICU decreased lymphocytes, granulocytes and mononuclear cells in patients with acute cerebral hemorrhage. The levels of inflammatory factors were associated with brain edema in patients with acute cerebral hemorrhage treated at the ICU. In addition, the amount of bleeding was reduced in parallel with the inflammatory cell plasma concentration of lymphocytes, granulocytes and mononuclear cells. Importantly, Simvastatin treatment produced beneficial outcomes by improving brain edema and reducing the amount of bleeding. In conclusion, the present study demonstrated the efficacy of Simvastatin in treating acute intracerebral hemorrhage and evidenced the association between inflammatory responses and the progress of affected patients at the ICU, thereby providing insight for applying effective therapies for patients with acute intracerebral hemorrhage.

Clinical evidence of efficacy of simvastatin for aneurysmal subarachnoid hemorrhage

Objective

The present study was performed to explore the therapeutic potential of simvastatin in subarachnoid hemorrhage (SAH) in the context of the Simvastatin in Aneurysmal Subarachnoid Hemorrhage (STASH) trial.

Methods

MEDLINE, EMBASE, and the Cochrane Library were searched for all randomized controlled trials (RCTs) investigating the therapeutic effect of simvastatin on aneurysmal SAH. We applied a random-effects model to calculate the data.

Results

Five RCTs involving 951 patients met the eligibility criteria. We found no statistically significant effects on vasospasm detected by transcranial cerebral Doppler (relative risk [RR], 0.91; 95% confidence interval [CI], 0.55–1.49), delayed cerebral ischemia (DCI) (RR, 0.85; 95% CI, 0.63–1.14), or all-cause mortality (RR, 1.02; 95% CI, 0.67–1.54). Subgroup analysis showed that these consolidated results were stable at different doses, different times to start of treatment, and different courses of treatment in all included RCTs. Sensitivity analysis showed that the STASH trial, which had a large population, did not influence the consolidated results of all three outcomes.

Conclusions

Simvastatin showed no benefits in decreasing the incidence of vasospasm, DCI, or all-cause mortality after aneurysmal SAH. We conclude that patients with SAH should not be treated routinely with simvastatin during the acute stage.

Dose-related effect of statins in patients with endovascular coiling or microsurgical clipping for aneurysmal subarachnoid hemorrhage: updated study-level meta-analysis

PURPOSE

We aimed to quantitatively assess the effects of short-term statin use on delayed ischemic neurologic deficits (DINDs) and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH) through a meta-analysis of the available evidence.

METHODS

We searched the electronic databases up to April 8, 2016 to retrieve relevant studies comparing the outcomes between immediate statin-treated in statin-naïve patients and untreated patients following aneurysmal SAH. Meta-analysis was performed using Review Manager 5.3.

RESULTS

Eight randomized controlled clinical trials (RCTs) and 5 observational studies involving 2148 patients met the eligibility criteria. In the RCTs, statins were found to significantly reduce the occurrence of DINDs (relative risk (RR), 0.76; 95% confidence interval (CI), 0.61-0.94; P = 0.01), but did not significantly reduce poor functional outcomes (RR, 1.01; 95% CI, 0.87-1.16; P = 0.93) or mortality (RR, 0.80; 95% CI, 0.58-1.11; P = 0.18). In observational studies, statin use was not associated with any reduction in DINDs, poor outcome, or mortality. Meta-analysis of RCTs indicated a significant reduction in DINDs and mortality in patients with high-dose statin use (RR, 0.63; 95% CI, 0.42-0.95; P = 0.03; I ² = 0%; and RR, 0.36; 95% CI, 0.15-0.86; P = 0.02; I ² = 0%, respectively).

CONCLUSION

The present meta-analysis suggests that statin use may prevent DINDs in patients with aneurysmal SAH. Based on our findings, the role of statins in improving neurological outcome was limited. However, the risk of DINDs and mortality decreased with higher statin doses in a dose-dependent manner. Hence, further well-designed RCTs with modified protocols in specific patients are required.

Effect of statin treatment on vasospasm-related morbidity and functional outcome in patients with aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

OBJECTIVE The efficacy of statin therapy in treating aneurysmal subarachnoid hemorrhage (SAH) remains controversial. In this meta-analysis, the authors investigated whether statin treatment significantly reduced the incidence of cerebral vasospasm and delayed neurological deficits, promoting a better outcome after aneurysmal SAH. METHODS A literature search of the PubMed, Ovid, and Cochrane Library databases was performed for randomized controlled trials (RCTs) and prospective cohort studies investigating the effect of statin treatment. The end points of cerebral vasospasm, delayed ischemic neurological deficit (DIND), delayed cerebral infarction, mortality, and favorable outcome were statistically analyzed. RESULTS Six RCTs and 2 prospective cohort studies met the eligibility criteria, and a total of 1461 patients were included. The meta-analysis demonstrated a significant decrease in the incidence of cerebral vasospasm (relative risk [RR] 0.76, 95% confidence interval [CI] 0.61-0.96) in patients treated with statins after aneurysmal SAH. However, no significant benefit was observed for DIND (RR 0.88, 95% CI 0.70-1.12), delayed cerebral infarction (RR 0.66, 95% CI 0.33-1.31), mortality (RR 0.69, 95% CI 0.39-1.24) or favorable outcome, according to assessment by the modified Rankin Scale or Glasgow Outcome Scale (RR 0.99, 95% CI 0.92-1.17). CONCLUSIONS Treatment with statins significantly decreased the occurrence of vasospasm after aneurysmal SAH. The incidence of DIND, delayed cerebral infarction, and mortality were not affected by statin treatment. Future research should focus on DIND and how statins influence DIND.

Mild hypothermia protects against early brain injury in rats following subarachnoid hemorrhage via the TrkB/ERK/CREB signaling pathway

Subarachnoid hemorrhage (SAH) is a severe neurological disease, which is associated with a significant number of cases of premature mortality and disability worldwide. Mild hypothermia (MH) has been proposed as a potential therapeutic strategy to reduce neuronal injury following SAH. The present study aimed to investigate the mechanisms of MH's protective role in the process of SAH. The present study demonstrated that MH was able to protect against early brain injury in a rat model of SAH. Treating SAH rats with MH reduced the release of reactive oxygen species and prevented activation of apoptotic cascades. Furthermore, the protective effects of MH were shown to be mediated by enhanced activity of the tropomyosin receptor kinase B/extracellular signal‑regulated kinases/cAMP response element binding protein (TrkB/ERK/CREB) pathway. Inhibition of TrkB/ERK/CREB activity using a small molecule inhibitor largely abolished the beneficial effects of MH in SAH rats. These results outline an endogenous mechanism underlying the neuroprotective effects of MH in SAH.

Atorvastatin ameliorates early brain injury after subarachnoid hemorrhage via inhibition of AQP4 expression in rabbits

The therapeutic effects of atorvastatin on early brain injury (EBI), cerebral edema and its association with aquaporin 4 (AQP4) were studied in rabbits after subarachnoid hemorrhage (SAH) using western blot analysis and the dry-wet method. Seventy-two healthy male New Zealand rabbits weighing between 2.5 and 3.2 kg were randomly divided into three groups: the SAH group (n=24), sham-operated group (n=24) and the SAH + atorvastatin group (n=24). A double SAH model was employed. The sham-operated group were injected with the same dose of saline solution, the SAH + atorvastatin group received atorvastatin 20 mg/kg/day after SAH. All rabbit brain samples were taken at 72 h after the SAH model was established successfully. Brain edema was detected using the dry-wet method after experimental SAH was induced; AQP4 and caspase-3 expression was measured by western blot analysis, and neuronal apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining at 72 h after SAH. The results indicated that brain edema and injury appeared soon after SAH, while brain edema and EBI were ameliorated and increased behavior scores were noted after prophylactic use of atorvastatin. Compared with the SAH group, the level of AQP4 and the cerebral content of water was significantly decreased (P<0.01) by atorvastatin, and TUNEL staining and studying the expression of caspase-3 showed that the apoptosis of neurons was reduced markedly both in the hippocampus and brain cortex by atorvastatin. The results suggest that atorvastatin ameliorated brain edema and EBI after SAH, which was related to its inhibition of AQP4 expression. Our findings provide evidence that atorvastatin is an effective and well-tolerated approach for treating SAH in various clinical settings.

High-Dose Simvastatin Is Effective in Preventing Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study in Korean Patients

Objective

The goal of this study was to assess the effect of high-dose simvastatin on cerebral vasospasm and its clinical outcome after aneurysmal subarachnoid hemorrhage (SAH) in Korean patients.

Methods

This study was designed as a prospective observational cohort study. Its subjects were aneurysmal SAH patients who had undergone aneurysm clipping or coiling. They were assigned to 1 of 3 groups : the 20 mg, 40 mg, and 80 mg simvastatin groups. The primary end-point was the occurrence of symptomatic vasospasm. The clinical outcome was assessed with the modified Rankin Scale (mRS) score after 1 month and 3 months. The risk factors of the development of vasospasm were assessed by logistic regression analysis.

Results

Ninety nine patients with aneurysmal SAH were treated and screened. They were sequentially assigned to the 20 mg (n=22), 40 mg (n=34), and 80 mg (n=31) simvastatin groups. Symptomatic vasospasm occurred in 36.4% of the 20 mg group, 8.8% of the 40 mg group, and 3.2% of the 80 mg group (p=0.003). The multiple logistic regression analysis showed that poor Hunt-Hess grades (OR=5.4 and 95% CI=1.09-26.62) and high-dose (80 mg) simvastatin (OR=0.09 and 95% CI=0.1-0.85) were independent factors of symptomatic vasospasm. The clinical outcomes did not show a significant difference among the three groups.

Conclusion

This study demonstrated that 80 mg simvastatin treatment was effective in preventing cerebral vasospasm after aneurysmal SAH, but did not improve the clinical outcome in Korean patients.

Risk Factors for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature

OBJECTIVE

To examine the literature on risk factors for cerebral vasospasm (CV), one of the most serious complications following aneurysmal subarachnoid hemorrhage (SAH), with special reference to the definition of CV.

METHODS

Using standard search engines, including PubMed, the medical literature on risk factors for CV after SAH was reviewed, and the best definition representative of CV was searched.

RESULTS

Severe SAH evident on computed tomography scan was the only consistent risk factor for CV after SAH. Effects of risk factors on CV, including age, clinical grade, rebleeding, intraventricular or intracerebral hemorrhage on computed tomography scan, acute hydrocephalus, aneurysm site and size, leukocytosis, interleukin-6 level, and cardiac abnormalities, appeared to be associated with the severity of SAH rather than each having a direct effect. Cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram were associated with CV without any relationship to SAH severity. With regard to parameters representative of CV, the grade of angiographic vasospasm (i.e., the degree of arterial narrowing evident on angiography) was the most adequate. Nevertheless, few reports on the risk factors associated with angiographic vasospasm grade have been reported to date.

CONCLUSIONS

Severe SAH evident on computed tomography scan appears to be a definite risk factor for CV after SAH, followed by cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram. To understand the pathogenesis of CV, further studies on the relationships between risk factors, especially factors not related to the severity of SAH, and angiographic vasospasm grade are necessary.

Inflammation, vasospasm, and brain injury after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) can lead to devastating neurological outcomes, and there are few pharmacologic treatments available for treating this condition. Both animal and human studies provide evidence of inflammation being a driving force behind the pathology of SAH, leading to both direct brain injury and vasospasm, which in turn leads to ischemic brain injury. Several inflammatory mediators that are elevated after SAH have been studied in detail. While there is promising data indicating that blocking these factors might benefit patients after SAH, there has been little success in clinical trials. One of the key factors that complicates clinical trials of SAH is the variability of the initial injury and subsequent inflammatory response. It is likely that both genetic and environmental factors contribute to the variability of patients' post-SAH inflammatory response and that this confounds trials of anti-inflammatory therapies. Additionally, systemic inflammation from other conditions that affect patients with SAH could contribute to brain injury and vasospasm after SAH. Continuing work on biomarkers of inflammation after SAH may lead to development of patient-specific anti-inflammatory therapies to improve outcome after SAH.

Simvastatin in aneurysmal subarachnoid haemorrhage (STASH): a multicentre randomised phase 3 trial

BACKGROUND

The benefit of statins in patients with acute aneurysmal subarachnoid haemorrhage is unclear. We aimed to determine whether simvastatin 40 mg could improve the long-term outcome in patients with this disorder.

METHODS

In this international, multicentre, randomised, double-blind trial, we enrolled patients aged 18-65 years with confirmatory evidence of an aneurysmal subarachnoid haemorrhage and presenting less than 96 h from ictus from 35 acute neurosurgical centres in nine countries. Patients were randomly allocated (1:1) to receive either simvastatin 40 mg or placebo once a day for up to 21 days. We used a computer-generated randomisation code to randomise patients in every centre by blocks of ten (five simvastatin, five placebo). Participants and investigators were masked to treatment assignment. The primary outcome was the distribution of modified Rankin Scale (mRS) score obtained by questionnaire at 6 months. Analyses were done on the intention-to-treat population. This trial has been completed and is registered with Current Controlled Trials, number ISRCTN75948817.

FINDINGS

Between Jan 6, 2007, and Feb 1, 2013, apart from the period between May 15, 2009, and Feb 8, 2011, when recruitment was on hold, 803 patients were randomly assigned to receive either simvastatin 40 mg (n=391) or placebo (n=412). All patients were included in the intention-to-treat population. 782 (97%) patients had outcome data recorded at 6 months, of whom 560 (72%) were classed as having a favourable outcome, mRS 0-2 (271 patients in the simvastatin group vs 289 in the placebo group). The primary ordinal analysis of the mRS, adjusted for age and World Federation of Neurological Surgeons grade on admission, gave a common odds ratio (OR) of 0·97, 95% CI 0·75-1·25; p=0·803. At 6 months, we recorded 37 (10%) deaths in the simvastatin group compared with 35 (9%) in the placebo group (log-rank p=0·592). 70 (18%) serious adverse events were reported in the simvastatin group compared with 74 (18%) in the placebo group. No suspected unexpected serious adverse reactions were reported.

INTERPRETATION

The STASH trial did not detect any benefit in the use of simvastatin for long-term or short-term outcome in patients with aneurysmal subarachnoid haemorrhage. Despite demonstrating no safety concerns, we conclude that patients with subarachnoid haemorrhage should not be treated routinely with simvastatin during the acute stages.

FUNDING

British Heart Foundation.

Preadmission statin use does not improve functional outcomes or prevent delayed ischemic events in patients with spontaneous subarachnoid hemorrhage

STUDY OBJECTIVE

To determine whether preadmission statin use in patients with spontaneous subarachnoid hemorrhage (SAH) is associated with improved functional outcomes and a lower incidence of delayed cerebral ischemic events compared with statin-naive patients with SAH.

DESIGN

Prospective cohort study.

SETTING

Neurosciences intensive care unit of a tertiary care hospital.

PATIENTS

A total of 295 consecutive patients with SAH admitted between March 2006 and May 2013 who had complete medication histories; of these patients, 41 reported taking a statin prior to admission, and 254 were statin naive.

INTERVENTION

All patients received clinical management for SAH according to hospital protocol for standard care that included acute statin therapy with enteral pravastatin 40 mg/day on hospital day 1 for up to 21 days.

MEASUREMENTS AND MAIN RESULTS

Functional outcomes were assessed by using the modified Rankin Scale (mRS) at 14 days, 28 days, and 3 months. Delayed cerebral ischemia was assessed by using clinical evaluation and computed tomography. Patients taking statins prior to admission were more likely to have a history of diabetes mellitus, hypertension, coronary artery disease, and stroke. No significant difference in favorable neurologic outcome (mRS score 0-3) at 3 months was observed between the preadmission statin group compared with the statin-naive group (56.3% vs 72.4%, p=0.095). In multivariate logistic regression analysis, only age, severity of rupture, and coronary artery disease were less likely to predict a favorable neurologic outcome. No significant difference in the development of delayed cerebral ischemic events was observed between groups (p=0.48).

CONCLUSION

Statin use prior to admission did not improve functional outcomes or prevent delayed cerebral ischemic events in patients with SAH. Age, severity of rupture, and coronary artery disease were less likely to predict a favorable neurologic outcome at 3 months after discharge.

Effects of statins-use for patients with aneurysmal subarachnoid hemorrhage: a meta-analysis of randomized controlled trials

Aneurysmal subarachnoid hemorrhage (aSAH)-induced cerebral vasospasm and delayed ischemic neurological deficit (DIND) are the major causes of morbidity and mortality in patients with aSAH. The effects of statins-use for patients with aSAH remain controversial. Here,a total of 249 patients from six randomized controlled trials(RCTs) were subjected to meta-analysis. No significant decrease was found in the incidence of vasospasm(RR, 0.80; 95% CI, 0.54-1.17), with substantial heterogeneity (I(2) = 49%, P = 0.08), which was verified by the further sensitivity analysis and subgroup meta-analysis. Furthermore, no significant difference was presented in the incidence of poor neurological outcome(RR, 0.94; 95% CI, 0.77-1.16), and potential side effects(RR, 2.49; 95% CI, 0.75-8.33). Nevertheless, significant difference was reported in the occurrence of DIND(RR, 0.58; 95% CI, 0.37-0.92) and mortality(RR, 0.30; 95% CI, 0.14-0.64). At present, although statins-use in the patients with aSAH should not be considered standard care at present, statins-use may have the potential effects in the prevention of mortality in patients with aSAH.

Effects of atorvastatin on plasma matrix metalloproteinase-9 concentration after glial tumor resection; a randomized, double blind, placebo controlled trial

Background

Neurosurgical procedures such as craniotomy and brain tumor resection could potentially lead to unavoidable cerebral injuries. Matrix metalloproteinase-9 (MMP-9) is up-regulated in neurological injuries. Statins have been suggested to reduce MMP- 9 level and lead to neuroprotection. Atorvastatin preoperatively administered to evaluate its neuroprotective effects and outcome assessment in neurosurgical-induced brain injuries after glial tumor resection. In this prospective, randomized, double-blind, placebo-controlled trial, 42 patients undergoing glial tumor surgery randomly received 40 mg atorvastatin or placebo twice daily from seven days prior to operation and continued for a 3 weeks period. Plasma MMP-9 concentration measured 4 times, immediately before starting atorvastatin or placebo, immediately before surgery, 24 hours and two weeks after the surgery. Karnofsky performance score was assessed before first dose of atorvastatin as a baseline and 2 months after the surgery.

Results

Karnofsky performance scale after surgery raised significantly more in Atorvastatin group (11.43 +/- 10.62 vs. 4.00 +/- 8.21) (p = 0.03). Atorvastatin did not significantly reduce MMP-9 plasma concentration 24 hours after surgery in comparison to placebo. No statistical significance detected regarding length of hospital stay among the groups. Significant reduction in MMP-9 plasma concentration was recorded in atorvastatin group two weeks after surgery (p = 0.048).

Conclusions

Significant statistical differences detected with atorvastatin group regarding MMP-9 plasma concentration, clinical outcome and Karnofsky performance score. Consequently, atorvastatin use may lead to better outcome after neurosurgical procedures.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Cholesterol-reducing agents for aneurysmal subarachnoid haemorrhage

BACKGROUND

Cerebral vasospasm and related delayed ischaemic deficits (DIDs) occur in about 17% to 40% of patients with aneurysmal subarachnoid haemorrhage (SAH) and lead to a poor outcome. Cholesterol-reducing agents might improve unfavourable outcomes.

OBJECTIVES

To assess the effects of cholesterol-reducing agents for improving outcomes in patients with aneurysmal SAH.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (May 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5), MEDLINE (1948 to May 2012) and EMBASE (1980 to May 2012). We also searched three Chinese databases: SinoMed, CNKI and VIP (May 2012). In an effort to identify further published, ongoing and unpublished trials we searched relevant clinical trials and research registers (May 2012), contacted pharmaceutical companies and investigators known to be involved in previous trials and screened the reference lists of all relevant articles identified.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared cholesterol-reducing agents with control or placebo treatment in participants with aneurysmal SAH.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, reviewed the relevant trials and extracted data. We did not perform meta-analysis as we only included one RCT in the review.

MAIN RESULTS

We included one study in which 39 patients received either simvastatin (80 mg daily; n = 19) or placebo (n = 20) for 14 days. The incidence of DIDs (secondary outcome) was 26% (5/19) in the simvastatin group versus 60% (12/20) in the placebo group (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.19 to 1.01, P = 0.05). This means that, in this study, simvastatin had no effect on DIDs. Two patients in the simvastatin group and one patient in the placebo group had elevated levels of aspartate transaminase or alanine transaminase. One patient in the simvastatin group had a raised creatine phosphokinase. There were no results from this trial for the primary outcome of death or dependency at six months.

AUTHORS' CONCLUSIONS

We cannot draw any conclusions about the effectiveness and safety of lowering cholesterol in aneurysmal SAH because of insufficient reliable evidence from only one small trial. More RCTs are needed.

Role of simvastatin in prevention of vasospasm and improving functional outcome after aneurysmal sub-arachnoid hemorrhage: a prospective, randomized, double-blind, placebo-controlled pilot trial

BACKGROUND

Vasospasm plays a major role in the morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). The preliminary studies suggest that statins protect against cerebral vasospasm.

OBJECTIVE

The aim of the study was to determine the role of simvastatin in preventing clinical vasospasm and improving functional outcome in patients with aSAH.

METHODS

All patients with aSAH admitted within 96 h of ictus were randomized to receive either Simvastatin or placebo - 80 mg/day for 14 days. Thirty eight patients were recruited in the study- 19 received Simvastatin and 19 placebo. All the patients underwent surgical clipping of the aneurysm. The primary outcome of the study was the development of clinical cerebral vasospasm. The secondary outcomes included Glasgow Outcome Score (GOS), Modified Rankin Scale (MRS) and Barthel Index Score (MBI) at follow-up at 1, 3 and 6 months.

RESULTS

16% of the patients in the simvastatin group had high Middle Cerebral Artery velocities (> 160 cm/sec) on transcranial Doppler on one or more than one day during the study duration as compared to 26% of the patients in the placebo group (p = 0.70). Neurological deterioration occurred in 26% and 42% of the patients in simvastatin group versus placebo group, respectively (p = 0.31). There was an improvement in the functional outcome in the simvastatin group at 1, 3 or 6 months in the follow-up; however, this difference was not statistically significant.

CONCLUSIONS

There was benefit of simvastatin in terms of reduction in clinical vasospasm, mortality or improved functional outcome, however, this was not statistically significant.

Statins in the critically ill

The use or misuse of statins in critically ill patients recently attracted the attention of intensive care clinicians. Indeed, statins are probably the most common chronic treatment before critical illness and some recent experimental and clinical data demonstrated their beneficial effects during sepsis, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), or after aneurismal subarachnoidal hemorrhage (aSAH). Due to the heterogeneity of current studies and the lack of well-designed prospective studies, definitive conclusions for systematic and large-scale utilization in intensive care units cannot be drawn from the published evidence. Furthermore, the extent of statins side effects in critically ill patients is still unknown. For the intensive care clinician, it is a matter of individually identifying the patient who can benefit from this therapy according to the current literature. The purpose of this review is to describe the mechanisms of actions of statins and to synthesize the clinical data that underline the relevant effects of statins in the particular setting of critical care, in an attempt to guide the clinician through his daily practice.

Serum C-reactive protein levels predict neurological outcome after aneurysmal subarachnoid hemorrhage

OBJECTIVES: Our aim was to evaluate the relationship between serum C-reactive protein (CRP) levels and the neurological prognosis and development of vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Eighty-two adult patients with aSAH diagnoses were prospectively evaluated. Glasgow Coma Scale (GCS) score, Hunt and Hess grade, Fisher grade, cranial CT scans, digital subtraction angiography studies and daily neurological examinations were recorded. Serial serum CRP measurements were obtained daily between admission and the tenth day. Glasgow Outcome Scale (GOS) and the modified Rankin Scale (mRS) were used to assess the prognosis. RESULTS: Serum CRP levels were related to severity of aSAH. Patients with lower GCS scores and higher Hunt and Hess and Fisher grades presented statistically significant higher serum CRP levels. Patients with higher serum CRP levels had a less favorable prognosis. CONCLUSIONS: Increased serum CRP levels were strongly associated with worse clinical prognosis in this study.

Summary of evidence on immediate statins therapy following aneurysmal subarachnoid hemorrhage

Statins were shown to have neuroprotective effects, with reduced vasospasm and delayed ischemic deficits in statin-treated patients after aneurysmal subarachnoid hemorrhage in two small, randomized, controlled clinical trials published in 2005. This review consolidated data from available published studies evaluating statin treatment for subarachnoid hemorrhage. A literature search was conducted to identify original research studies published through October 2010 testing immediate treatment with a statin in statin-naïve patients following aneurysmal SAH. Six randomized controlled clinical trials and four observational studies were identified. Despite inconsistent results among studies, a meta-analysis of randomized controlled data showed a significant reduction in delayed ischemic deficits with statins. Effect on vasospasm was more difficult to determine, due to differences in definitions used among studies. Interpretations from observational studies were limited by the use of relatively small sample sizes, historical controls, and treatment variability.

Outcomes from intracerebral hemorrhage among patients pre-treated with statins

OBJECTIVE: 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, have been associated with improved clinical outcomes after ischemic stroke and subarachnoid hemorrhage, but with an increased risk of incidental spontaneous intracerebral hemorrhage (ICH). We investigated whether the statin use before ICH, was associated with functional independence, 90 days after treatment. METHOD: We analyzed 124 consecutive ICH patients with 90-day outcome data who were enrolled in a prospective cohort study between 2006 and 2009. Eighty-three patients were included in this study. Among ICH survivors, univariate Cox regression models and Kaplan-Meier plots were used to determine subject characteristics that were associated with an increased risk of recurrence. Statin usage was determined through interviewing the patient at the time of ICH and confirmed by reviewing their medical records. Independent status was defined as Glasgow Outcome Scale grades 4 or 5. RESULTS: Statins were used by 20 out of 83 patients (24%) before ICH onset. There was no effect from pre-ICH statin use on functional independence rates (28% versus 29%, P=0.84) or mortality (46% versus 45%, P=0.93). CONCLUSION: Pre-ICH statin use is not associated with changes to ICH functional outcome or mortality.

Statins in the management of aneurysmal subarachnoid hemorrhage: an overview of animal research, observational studies, randomized controlled trials and meta-analyses

BACKGROUND

the pathophysiology of delayed neurological deficits (DNDs) following aneurysmal subarachnoid hemorrhage (SAH) is complex, and is not limited to arterial narrowing (vasospasm) and classical ischemia. Thus, combined drug approaches, or therapies with multiple effects, may have the greatest potential for benefit. Statins are known to have pleiotropic vascular effects, some of which may interrupt the pathogenesis of DNDs. Based on promising preliminary reports, many clinicians routinely administer statins to prevent DNDs.

METHODS

a systematic review was performed to identify and summarize all animal research, observational studies, randomized controlled trials (RCTs) and meta-analyses which have evaluated the use of statins in the management of SAH.

RESULTS

nine animal studies, nine observational (cohort and case-control) studies, six RCTs and three meta-analyses were identified. Animal studies have generally administered statin doses that, when adjusted for body weight, are 10-80 times larger than what is used in humans. Nevertheless, these models have consistently reported statins to reduce vasospasm and to demonstrate additional neuroprotective effects. However, observational studies have not revealed an association between statin-use and reduced DNDs or improved neurological outcomes. Results of RCTs have been inconsistent and limited by small sample size, but together suggest that statins may reduce DNDs, with no clear impact on mortality or neurological recovery. Optimal drug administration strategies (timing of initiation, most effective dose and duration) have not been clarified.

CONCLUSIONS

the role of statins in the management of patients with SAH remains unclear. Although promising, statins should not, at this time, be considered standard care.

Nitric oxide in early brain injury after subarachnoid hemorrhage

Nitric Oxide (NO) is the major regulator of cerebral blood flow. In addition, it inhibits platelet adherence and aggregation, reduces adherence of leukocytes to the endothelium, and suppresses vessel injury. NO is produced on demand by nitric oxide synthase and has a very short half life. Hence maintenance of its cerebral level is crucial for normal vascular physiology. Time dependent alterations in cerebral NO level and the enzymes responsible for its synthesis are found after subarachnoid hemorrhage (SAH). Cerebral NO level decreases, recovers and increases within the first 24 h after SAH. Each change in cerebral NO level elicits a different pathological response form already compromised brain. These response range from constriction, platelet aggregation and vascular injury that occurs during the early hours and delayed occurring vasospasm, neuronal and axonal damage. This review summarizes the underlying mechanism and the consequence of alteration in cerebral NO level on brain during the first 72 h after SAH.

Resistant vasospasm in subarachnoid hemorrhage treated with continuous intraarterial nimodipine infusion

Cerebral vasospasm complicating aneurysmal subarachnoid hemorrhage is a well-known medical entity. The delayed ischemic neurological deficits (DIND) as a result of vasospasm remain the main cause of morbidity among patients who manage to survive this severe disease pattern. When the traditional treatment options, either medical or interventional, fail to reverse vasospasm, continuous intraarterial infusion of nimodipine through catheters directly into the spastic arteries presents a promising treatment modality. Of 73 patients with aneurysmal subarachnoid hemorrhage between 2008 and 2009, a total of 27 had Hunt and Hess grades of 4 and 5. Fifteen percent of them showed refractory vasospasms and were treated with continuous nimodipine infusion via catheters in both internal carotid arteries. We present the method's indications and possible complications.

Inflammation and cerebral vasospasm after subarachnoid hemorrhage

Morbidity and mortality of patients with aneurysmal subarachnoid hemorrhage (aSAH) is significantly related to the development of chronic cerebral vasospasm. Despite extensive clinical and experimental research, the pathophysiology of the events that result in delayed arterial spasm is not fully understood. A review of the published literature on cerebral vasospasm that included but was not limited to all PubMed citations from 1951 to the present was performed. The findings suggest that leukocyte-endothelial cell interactions play a significant role in the pathophysiology of cerebral vasospasm and explain the clinical variability and time course of the disease. Experimental therapeutic targeting of the inflammatory response when timed correctly can prevent vasospasm, and supplementation of endothelial relaxation by nitric oxide-related therapies and other approaches could result in reversal of the arterial narrowing and improved outcomes in patients with aSAH.

[Effect of the administration of statins in non-cardiac critical disease]

Administration of statins has been shown to be effective in reducing cardiovascular mortality. Their benefit could expand towards other areas of intensive medicine, it being possible to decrease mortality of the critically ill patient. There are several studies, although without a high level of evidence, that have detected a possible benefit when they are administered as well as clinical deterioration when they are discontinued, compared to those patients who had previously taken them. Even though most of the patients who had previously taken statins did so as primary or secondary prevention, thus having greater comorbidity, overall, a decrease is detected in the mortality of these subgroups. This benefit could be generalized to all the critical conditions, although studies with a higher level of evidence are needed for their adequate comparison.

Statins in the management of patients with aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

BACKGROUND

Delayed ischemic neurological deficits (DINDs) contribute to morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Based on promising preliminary reports, some clinicians routinely administer statins to prevent DINDs.

METHODS

Without language restriction, we searched MEDLINE, EMBASE, the Cochrane Central Register, references of review articles, proceedings of the International Stroke Conference, and gray literature sources. Studies were selected if they compared outcomes between statin-treated and untreated patients during the 2 weeks following SAH. Data were extracted and appraised independently and in duplicate, using standardized forms. Fixed or random effects models, as appropriate based on the degree of study heterogeneity, were applied to calculate summary measures.

RESULTS

Four RCTs, two "pseudo" RCTs, five cohort studies, and one case-control study met eligibility criteria. In the RCTs, which enrolled a total of 309 patients, statins were found to significantly reduce the occurrence of DINDs [OR 0.38 (0.23-0.65); P < 0.001], but not mortality [OR 0.51 (0.25-1.02); P = 0.06] or poor neurological recovery [OR 0.81 (0.49-1.32); P = 0.39]. Observational studies assessed 1,542 patients, of whom 385 received statins. Statin-use was not associated with any reduction in DINDs [OR 0.96 (0.71-1.31); P = 0.80], mortality [OR 1.16 (0.78-1.73); P = 0.47] or poor neurological recovery [OR 1.20 (0.84-1.72); P = 0.31]. When the results of all studies were combined, statins had no statistically significant effect.

CONCLUSIONS

Existing RCTs suggest that statins reduce DINDs, with a possible trend toward lower mortality. These findings are not supported by observational research. Although not assessed in all studies, current data do not indicate that statins improve neurological outcomes.

Statins in traumatic brain injury

Traumatic brain injury (TBI) is a common cause of long-term neurological morbidity, with devastating personal and societal consequences. At present, no pharmacological intervention clearly improves outcomes, and therefore a compelling unmet clinical need remains. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or "statins," offer a potential novel therapeutic strategy for TBI. Statins are well tolerated, easy to administer, and have a long clinical track record in critically ill patients. Their side effects are well defined and easily monitored. Preclinical studies have shown significant benefit of statins in models of TBI and related disease processes, including cerebral ischemia, intracerebral hemorrhage, and subarachnoid hemorrhage. In fact, multiple mechanisms have been defined by which statins may exert benefit after acute brain injury. Statins are currently positioned to be translated into clinical trials in acute brain injury and have the potential to improve outcomes after TBI.

Simvastatin activates Akt/glycogen synthase kinase-3beta signal and inhibits caspase-3 activation after experimental subarachnoid hemorrhage

This study was designed to explore the role of simvastatin and its effects on the Akt/GSK3beta survival signal and apoptosis pathway after experimental subarachnoid hemorrhage (SAH). SAH was induced by blood injection into the cisterna magna in New Zealand white rabbits. Increased expression of phospho-Akt and phospho-GSK3beta was observed in brain tissue after SAH. Apoptosis and related proteins, including P53, apoptosis-inducing factor (AIF), cytochrome C, and cleaved caspase-3, were also activated. Simvastatin, at both low dose (10 mg/kg) and high dose (40 mg/kg), further increased expression of phospho-Akt and phospho-GSK3beta, decreased activation of caspase-3, and inhibited apoptosis. Preserved blood-brain barrier and attenuated brain edema were observed following simvastatin treatment. In addition, the neuroprotective effects of simvastatin were blocked by wortmannin (2.5 microg/kg/min), an irreversible PIK3 inhibitor. P53, AIF, and cytochrome C were not affected by simvastatin treatment. Findings from the present study suggest that simvastatin ameliorates acute brain injury after SAH. The potential mechanisms of action include activation of the Akt/GSK3beta survival signal and inhibition of caspase-dependent apoptosis pathway.