Subarachnoid Hemorrhage International Trialists data repository (SAHIT)

Therapies for Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is one of the most important complications of subarachnoid hemorrhage. Despite lack of prospective evidence, medical rescue interventions for DCI include hemodynamic augmentation using vasopressors or inotropes, with limited guidance on specific blood pressure and hemodynamic parameters. For DCI refractory to medical interventions, endovascular rescue therapies (ERTs), including intraarterial (IA) vasodilators and percutaneous transluminal balloon angioplasty, are the cornerstone of management. Although there are no randomized controlled trials assessing the efficacy of ERTs for DCI and their impact on subarachnoid hemorrhage outcomes, survey studies suggest that they are widely used in clinical practice with significant variability worldwide. IA vasodilators are first line ERTs, with better safety profiles and access to distal vasculature. The most commonly used IA vasodilators include calcium channel blockers, with milrinone gaining popularity in more recent publications. Balloon angioplasty achieves better vasodilation compared with IA vasodilators but is associated with higher risk of life-threatening vascular complications and is reserved for proximal severe refractory vasospasm. The existing literature on DCI rescue therapies is limited by small sample sizes, significant variability in patient populations, lack of standardized methodology, variable definitions of DCI, poorly reported outcomes, lack of long-term functional, cognitive, and patient-centered outcomes, and lack of control groups. Therefore, our current ability to interpret clinical results and make reliable recommendations regarding the use of rescue therapies is limited. This review summarizes existing literature on rescue therapies for DCI, provides practical guidance, and identifies future research needs.

Sex and Racial Disparity in Outcome of Aneurysmal Subarachnoid Hemorrhage in the United States: A 20-Year Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage is associated with high rate of morbidity and mortality. We aimed to assess prognostic impact of sex, race, and ethnicity in these patients.

METHODS

Nationwide Inpatient Sample (2000-2019) was used to identify patients presenting with aneurysmal subarachnoid hemorrhage as primary diagnosis. Patient age, sex, race/ethnicity, insurance status, socioeconomic status, comorbidities, type of the hospital, and treatment modality used for aneurysm repair were extracted. The previously validated Nationwide Inpatient Sample Subarachnoid Hemorrhage Severity Scale was used to estimate the clinical severity. Discharge destination and in-hospital mortality was used as outcome measured. The impact of race/ethnicity and sex on clinical outcome was analyzed using multivariate regression models.

RESULTS

A total of 161 086 patients with aneurysmal subarachnoid hemorrhage were identified. Mean age was 55.0±13.8 years. Sixty-nine percent of the patients were female, 60% White patients, and 17% Black patients. There was no difference in the Nationwide Inpatient Sample Subarachnoid Hemorrhage Severity Scale score between the 2 sexes. Women had significantly lower odds of good clinical outcome (defined as discharge to home or acute rehabilitation facility; RR, 0.83 [95% CI, 0.74-0.94]; P=0.004). Hispanic patients (RR, 1.12 [95% CI, 1.07-1.17]; P<0.001) had higher odds of excellent clinical outcome compared with White patients, and lower risk of mortality were observed in Black patients (RR, 0.73 [95% CI, 0.66-0.81]) and Hispanic patients (RR, 0.78 [95% CI, 0.70-0.86]) compared with the White patients.

CONCLUSIONS

In this nationally representative study, women were less likely to have excellent outcomes following aneurysmal subarachnoid hemorrhage, and White patients had disproportionately higher likelihood of worse clinical outcomes. Lower rates of mortality were seen among Black and Hispanic patients.

External Validation of a Neural Network Model in Aneurysmal Subarachnoid Hemorrhage: A Comparison With Conventional Logistic Regression Models

BACKGROUND

Interest in machine learning (ML)-based predictive modeling has led to the development of models predicting outcomes after aneurysmal subarachnoid hemorrhage (aSAH), including the Nijmegen acute subarachnoid hemorrhage calculator (Nutshell). Generalizability of such models to external data remains unclear.

OBJECTIVE

To externally validate the performance of the Nutshell tool while comparing it with the conventional Subarachnoid Hemorrhage International Trialists (SAHIT) models and to review the ML literature on outcome prediction after aSAH and aneurysm treatment.

METHODS

A prospectively maintained database of patients with aSAH presenting consecutively to our institution in the 2013 to 2018 period was used. The web-based Nutshell and SAHIT calculators were used to derive the risks of poor long-term (12-18 months) outcomes and 30-day mortality. Discrimination was evaluated using the area under the curve (AUC), and calibration was investigated using calibration plots. The literature on relevant ML models was surveyed for a synopsis.

RESULTS

In 269 patients with aSAH, the SAHIT models outperformed the Nutshell tool (AUC: 0.786 vs 0.689, P = .025) in predicting long-term functional outcomes. A logistic regression model of the Nutshell variables derived from our data achieved adequate discrimination (AUC = 0.759) of poor outcomes. The SAHIT models outperformed the Nutshell tool in predicting 30-day mortality (AUC: 0.810 vs 0.636, P < .001). Calibration properties were more favorable for the SAHIT models. Most published aneurysm-related ML-based outcome models lack external validation and usable testing platforms.

CONCLUSION

The Nutshell tool demonstrated limited performance on external validation in comparison with the SAHIT models. External validation and the dissemination of testing platforms for ML models must be emphasized.

Big Data/AI in Neurocritical Care: Maybe/Summary

Big data (BD) and artificial intelligence (AI) have increasingly been used in neurocritical care. "BD" can be operationally defined as extremely large datasets that are so large and complex that they cannot be analyzed by using traditional statistical modeling. "AI" means the ability of machines to perform tasks similar to those performed by human intelligence. We present a brief overview of the most commonly applied AI techniques to perform BD analytics and discuss some of the recent promising examples in the field of neurocritical care. The latter include the following: cognitive motor dissociation in disorders of consciousness, hypoxic-ischemic injury following cardiac arrest, delayed cerebral ischemia and vasospasm after subarachnoid hemorrhage, and monitoring of intracranial pressure. It is imperative that we develop multicenter collaborations to tackle BD. These collaborations will allow us to share data, combine predictive algorithms, and analyze multiple and cumulative sources of data retrospectively and prospectively. Once AI algorithms are validated at multiple centers, they should be tested in randomized controlled trials investigating their impact on clinical outcome. The neurocritical care community must work to ensure that AI incorporates standards to ensure fairness and health equity rather than reflect our biases present in our collective conscience.

China Stroke Registry for Patients With Traditional Chinese Medicine (CASES-TCM): Rationale and Design of a Prospective, Multicenter, Observational Study

Background: Given the complexity of stroke treatment and the current widespread use of traditional Chinese medicine (TCM) in the absence of robust, large, long-term effectiveness and safety studies, and the lack of nationwide epidemiology and clinical characteristics of patients with stroke receiving TCM treatment, the acquisition of data from longitudinal cohorts is essential. We intend to generate the major clinical characteristics of patients with stroke who receive TCM treatment and to investigate the effectiveness and safety of TCM in the Chinese population.

Methods: The China Stroke Registry for Patients with Traditional Chinese Medicine (CASES-TCM) study is a prospective, multicenter, observational disease registry aiming to register 20,000 hospitalized patients. Eligible adult patients with clearly diagnosed acute ischemic stroke or intracerebral hemorrhage within 7 days of symptom onset will be consecutively registered from 126 participating sites across China. Baseline data will be recorded, and all patients will be regularly followed up at 3, 6, 12, and 24 months after stroke onset. Collected data will be entered into a web-based system with high-level data security. The primary outcomes include the distribution of scores on the modified Rankin Scale at the 3-months follow-up, and recurrent stroke events within the 12-months follow-up.

Conclusion: To our knowledge, the CASES-TCM study is the first and largest nationwide registry to document comprehensive data on TCM treatment in patients with acute stroke. The findings of this study will be valuable to improve our knowledge about TCM treatment for patients with stroke and its subsequent outcomes in the actual clinical setting, consequently facilitating and standardizing the optimization of individualized interventions with TCM for stroke prevention and treatment in China.

Study registration: This study was registered with Clinicaltrials.gov (URL: https://clinicaltrials.gov/, Unique identifier: NCT04921397).

Protective effects of BP-1-102 against intracranial aneurysms-induced impairments in mice

The development of non-invasive pharmacological therapies to prevent the progression and rupture of intracranial aneurysms (IAs) is an important field of research. This study attempts to reveal the role of BP-1-102, an oral bioavailable signal transducer and activator of transcription 3 (STAT3) inhibitor, in IA. We first constructed an IA mouse model by injecting elastase into the cerebrospinal fluid with simultaneous induction of hypertension by deoxycorticosterone acetate (DOCA) implantation. The results showed that the proportion of IA rupture in mice after BP-1-102 administration was significantly reduced, and the survival time was significantly extended. Further research showed that compared with the vehicle group, the proportion of macrophages infiltrated at the aneurysm and the expression of pro-inflammatory cytokines in the BP-1-102 administration group were significantly reduced. The contractile phenotype vascular smooth muscle cell (VSMC) specific markers, SM22α and αSMA, were significantly upregulated in the BP-1-102 group. Furthermore, we found that BP-1-102 inhibited the expression of critical proteins in the nuclear factor kappa-B and Janus kinase 2/STAT3 signalling pathways. Our study shows that BP-1-102 significantly decreases the rupture of IA, reduces the inflammatory responses and modulates the phenotype of VSMCs, suggesting that BP-1-102 could be utilised as a potential intervention drug for IA.

Rescue therapy for vasospasm following aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis with machine learning

OBJECTIVE

Rescue therapies have been recommended for patients with angiographic vasospasm (aVSP) and delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH). However, there is little evidence from randomized clinical trials that these therapies are safe and effective. The primary aim of this study was to apply game theory-based methods in explainable machine learning (ML) and propensity score matching to determine if rescue therapy was associated with better 3-month outcomes following post-SAH aVSP and DCI. The authors also sought to use these explainable ML methods to identify patient populations that were more likely to receive rescue therapy and factors associated with better outcomes after rescue therapy.

METHODS

Data for patients with aVSP or DCI after SAH were obtained from 8 clinical trials and 1 observational study in the Subarachnoid Hemorrhage International Trialists repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and the 3-month Glasgow Outcome Scale (GOS) score. Favorable outcome was defined as a 3-month GOS score of 4 or 5. Shapley Additive Explanation (SHAP) values were calculated for each patient-derived model to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy administration were used in a propensity score-matched analysis of rescue therapy and 3-month GOS scores.

RESULTS

The authors identified 1532 patients with aVSP or DCI. Predictive, explainable ML models revealed that aneurysm characteristics and neurological complications, but not admission neurological scores, carried the highest relative importance rankings in predicting whether rescue therapy was administered. Younger age and absence of cerebral ischemia/infarction were invariably linked to better rescue outcomes, whereas the other important predictors of outcome varied by rescue type (interventional or noninterventional). In a propensity score-matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS scores of 4-5 (OR 1.63, 95% CI 1.22-2.17).

CONCLUSIONS

Rescue therapy may increase the odds of good outcome in patients with aVSP or DCI after SAH. Given the strong association between cerebral ischemia/infarction and poor outcome, trials focusing on preventative or therapeutic interventions in these patients may be most able to demonstrate improvements in clinical outcomes. Insights developed from these models may be helpful for improving patient selection and trial design.

Aneurysmal Subarachnoid Hemorrhage: Trends, Outcomes, and Predictions From a 15-Year Perspective of a Single Neurocritical Care Unit

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with disproportionally high mortality and long-term neurological sequelae. Management of patients with aSAH has changed markedly over the years, leading to improvements in outcome.

OBJECTIVE

To describe trends in aSAH care and outcome in a high-volume single center 15-yr cohort.

METHODS

All new admissions diagnosed with subarachnoid hemorrhage (SAH) to our tertiary neuro-intensive care unit between 2002 and 2016 were reviewed. Trend analysis was performed to assess temporal changes and a step-wise regression analysis was done to identify factors associated with outcomes.

RESULTS

Out of 3970 admissions of patients with SAH, 2475 patients proved to have a ruptured intracranial aneurysm. Over the years of the study, patient acuity increased by Hunt & Hess (H&H) grade and related complications. Endovascular therapies became more prevalent over the years, and were correlated with better outcome. Functional outcome overall improved, yet the main effect was noted in the low- and intermediate-grade patients. Several parameters were associated with poor functional outcome, including long-term mechanical ventilation (odds ratio 11.99, CI 95% [7.15-20.63]), acute kidney injury (3.55 [1.64-8.24]), pneumonia (2.89 [1.89-4.42]), hydrocephalus (1.80 [1.24-2.63]) diabetes mellitus (1.71 [1.04-2.84]), seizures (1.69 [1.07-2.70], H&H (1.67 [1.45-1.94]), and age (1.06 [1.05-1.07]), while endovascular approach to treat the aneurysm, compared with clip-ligation, had a positive effect (0.35 [0.25-0.48]).

CONCLUSION

This large, single referral center, retrospective analysis reveals important trends in the treatment of aSAH. It also demonstrates that despite improvement in functional outcome over the years, systemic complications remain a significant risk factor for poor prognosis. The historic H&H determination of outcome is less valid with today's improved care.

Lessons from the CONSCIOUS-1 Study

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

External Validation of the Subarachnoid Hemorrhage International Trialists (SAHIT) Predictive Model Using the Barrow Ruptured Aneurysm Trial (BRAT) Cohort

BACKGROUND

The Subarachnoid Hemorrhage International Trialists (SAHIT) repository is a collection of randomized clinical trials, prospective observational studies, and hospital registries that was used to create a predictive model of unfavorable outcome/mortality following aneurysmal SAH.

OBJECTIVE

To externally validate the SAHIT model using Barrow Ruptured Aneurysm Trial (BRAT) data, which was not included in the SAHIT repository.

METHODS

This is a post hoc analysis of the prospective, randomized BRAT. Three models were created: (1) Core (age, hypertension, World Federation of Neurosurgical Societies grade), (2) neuroimaging (aneurysm size/location, Fisher score), and (3) full model (model 1 and 2 plus treatment type). The performance of the models was evaluated by measures of model discrimination (area under the curve [AUC]) and model calibration (goodness of fit test, calibration in-the-large, calibration slope).

RESULTS

A total of 338 patients (average age 54 years; 67.7% good clinical grade; average aneurysm size 6.7 mm; 84.1% anterior circulation) were included. Due to a large number of crossovers, more aneurysms were clipped than coiled (67.5% vs 32.5%, respectively). A total of 10.1% of the patients died and 29.6% experienced an unfavorable outcome. For unfavorable outcome, the AUCs for the three models were: 0.728, 0.732, and 0.734, respectively. For mortality, the AUCs for the three models were: 0.721, 0.739, and 0.744, respectively. Overall, all models showed good calibration, and the measures of calibration fell within 95% CI of those produced in the SAHIT study.

CONCLUSION

Using the BRAT data, we have externally validated the SAHIT model for predicting unfavorable outcome and mortality after SAH. The model may be used to counsel patients and families on prognosis following aneurysmal SAH.

Management of Aneurysmal Subarachnoid Hemorrhage: Variation in Clinical Practice and Unmet Need for Follow-up among Survivors-A Single-Center Perspective

OBJECTIVE

The purpose of the present study is to investigate the existence and/or prevalence of clinical practice variation in management of aneurysmal subarachnoid hemorrhage (aSAH) and to determine the need for long-term follow-up.

METHODS

A single-center study was carried out of patients with aSAH over a 5-year period divided into 2 halves (2.5 years each) before and after addition of a dually trained cerebrovascular neurosurgeon. In-hospital clinical practice, clinical outcome (mortality and discharge destination) and long-term outcome (modified Rankin Scale score and Telephone Interview for Cognitive Status [TICS]) were compared using descriptive summaries and nonparametric tests.

RESULTS

Among 251 patients admitted with aSAH, 115 (45.8%) were before the index event, whereas 136 (54.2%) were during the later period. The aneurysm-securing procedure changed from coil embolization to clip ligation (12/115 [10.4%] vs. 84/136 [61.8%]; P < 0.0001) during the latter years. Interventional treatment for cerebral vasospasm has decreased (58/115 [50.4%] vs. 49/136 [36.0%]; P = 0.0002). Patients surviving hospitalization had more clinic follow-up after discharge during the latter period (42/85 [49.4%] vs. 76/105 [72.4%]; P = 0.0012) and ventriculoperitoneal shunt placement for delayed hydrocephalus (1/85 [1.2%] vs. 9/105 [8.6%]; P = 0.02). A subcohort of aSAH survivors (n = 46) had lower median TICS score during the earlier study period (31.5 [interquartile range, 22-36] vs. 33 [interquartile range, 27-38]; P = 0.038). Similarly, preictal smoking status and hyperlipidemia were associated with adverse TICS score in a multivariate model (P = 0.007).

CONCLUSIONS

Postdischarge clinical follow-up has improved facilitating recognition and treatment of delayed hydrocephalus. Existence of cognitive deficits among survivors calls for establishment of multidisciplinary clinics for long-term management of aSAH.

Screening tools for early neuropsychological impairment after aneurysmal subarachnoid hemorrhage

BACKGROUND

Although most aneurysmal subarachnoid hemorrhage (aSAH) patients suffer from neuropsychological disabilities, outcome estimation is commonly based only on functional disability scales such as the modified Rankin Scale (mRS). Moreover, early neuropsychological screening tools are not used routinely.

OBJECTIVE

To study whether two simple neuropsychological screening tools identify neuropsychological deficits (NPDs), among aSAH patients categorized with favorable outcome (mRS 0-2) at discharge.

METHODS

We reviewed 170 consecutive aSAH patients that were registered in a prospective institutional database. We included all patients graded by the mRS at discharge, and who had additionally been evaluated by a neuropsychologist and/or occupational therapist using the Montreal Cognitive Assessment (MoCA) and/or Rapid Evaluation of Cognitive Function (ERFC). The proportion of patients with scores indicative of NPDs in each test were reported, and spearman correlation tests calculated the coefficients between the both neuropsychological test results and the mRS.

RESULTS

Of the 42 patients (24.7%) that were evaluated by at least one neuropsychological test, 34 (81.0%) were rated mRS 0-2 at discharge. Among these 34 patients, NPDs were identified in 14 (53.9%) according to the MoCA and 8 (66.7%) according to the ERFC. The mRS score was not correlated with the performance in the MoCA or ERFC.

CONCLUSION

The two screening tools implemented here frequently identified NPDs among aSAH patients that were categorized with favorable outcome according to the mRS. Our results suggest that MoCA or ERFC could be used to screen early NPDs in favorable outcome patients, who in turn might benefit from early neuropsychological rehabilitation.

Common Data Elements for Unruptured Intracranial Aneurysm and Subarachnoid Hemorrhage Clinical Research: Recommendations from the Working Group on Long-Term Therapies

OBJECTIVES

The goal for the long-term therapies (LTT) working group (WG) of the Unruptured Intracranial Aneurysm (UIA) and Subarachnoid Hemorrhage (SAH) common data elements (CDEs) was to develop a comprehensive set of CDEs, data definitions, case report forms, and guidelines for use in UIA and SAH LTT clinical research, as part of a new joint effort between the National Institute of Neurological Disorders and Stroke (NINDS) and the National Library of Medicine of the US National Institutes of Health. These UIA and SAH CDEs will join other neurological disease-specific CDEs already developed and available for use by research investigators.

METHODS

The eight LTT WG members comprised international UIA, and SAH experts reviewed existing NINDS CDEs and instruments, created new elements when needed, and provided recommendations for future LTT clinical research. The recommendations were compiled, internally reviewed by the all UIA and SAH WGs and steering committee members. The NINDS CDE team also reviewed the final version before posting the SAH Version 1.0 CDE recommendations on the NINDS CDE website.

RESULTS

The NINDS UIA and SAH LTT CDEs and supporting documents are publicly available on the NINDS CDE ( https://www.commondataelements.ninds.nih.gov/#page=Default ) and NIH Repository ( https://cde.nlm.nih.gov/home ) websites. The subcommittee members discussed and reviewed various parameters, outcomes, and endpoints in UIA and SAH LTT studies. The following meetings with WG members, the LTT WG's recommendations are incorporated into the disease/injury-related events, assessments and examinations, and treatment/intervention data domains.

CONCLUSIONS

Noting gaps in the literature regarding medication and rehabilitation parameters in UIA and SAH clinical studies, the current CDE recommendations aim to arouse interest to explore the impact of medication and rehabilitation treatments and therapies and encourage the convergence of LTT clinical study parameters to develop a harmonized standard.

The SAFARI Score to Assess the Risk of Convulsive Seizure During Admission for Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Seizure is a significant complication in patients under acute admission for aneurysmal SAH and could result in poor outcomes. Treatment strategies to optimize management will benefit from methods to better identify at-risk patients.

OBJECTIVE

To develop and validate a risk score for convulsive seizure during acute admission for SAH.

METHODS

A risk score was developed in 1500 patients from a single tertiary hospital and externally validated in 852 patients. Candidate predictors were identified by systematic review of the literature and were included in a backward stepwise logistic regression model with in-hospital seizure as a dependent variable. The risk score was assessed for discrimination using the area under the receiver operator characteristics curve (AUC) and for calibration using a goodness-of-fit test.

RESULTS

The SAFARI score, based on 4 items (age ≥ 60 yr, seizure occurrence before hospitalization, ruptured aneurysm in the anterior circulation, and hydrocephalus requiring cerebrospinal fluid diversion), had AUC = 0.77, 95% confidence interval (CI): 0.73-0.82 in the development cohort. The validation cohort had AUC = 0.65, 95% CI 0.56-0.73. A calibrated increase in the risk of seizure was noted with increasing SAFARI score points.

CONCLUSION

The SAFARI score is a simple tool that adequately stratified SAH patients according to their risk for seizure using a few readily derived predictor items. It may contribute to a more individualized management of seizure following SAH.

Tetramethylpyrazine Nitrone Reduces Oxidative Stress to Alleviate Cerebral Vasospasm in Experimental Subarachnoid Hemorrhage Models

Cerebral vasospasm is one of the deleterious complications after subarachnoid hemorrhage (SAH), leading to delayed cerebral ischemia and permanent neurological deficits or even death. Free radicals and oxidative stress are considered as crucial causes contributing to cerebral vasospasm and brain damage after SAH. Tetramethylpyrazine nitrone (TBN), a derivative of the clinically used anti-stroke drug tetramethylpyrazine armed with a powerful free radical scavenging nitrone moiety, has been reported to prevent brain damage from ischemic stroke. The present study aimed to investigate the effects of TBN on vasospasm and brain damage after SAH. Two experimental SAH models were used, a rat model by endovascular perforation and a rabbit model by intracisternal injection of autologous blood. The effects of TBN on SAH were evaluated assessing basilar artery spasm, neuronal apoptosis, and neurological deficits. TBN treatment significantly attenuated vasospasm, improved neurological behavior functions and reduced the number of apoptotic neurons in both the SAH rats and rabbits. Mechanistically, TBN suppressed the increase in 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine immuno-positive cells in the cortex of SAH rat brain. Western blot analyses indicated that TBN effectively reversed the altered expression of Bcl-2, Bax and cytochrome C, and up-regulated nuclear factor erythroid-derived 2-like 2 (Nrf2) and hemeoxygenase-1 (HO-1) protein expressions. In the in vitro studies, TBN inhibited H₂O₂-induced bEnd.3 cell apoptosis and reduced ROS generation. Additionally, TBN alleviated the contraction of rat basilar artery rings induced by H₂O₂ ex vivo. In conclusion, TBN ameliorated SAH-induced cerebral vasospasm and neuronal damage. These effects of TBN may be attributed to its anti-oxidative stress effect and up-regulation of Nrf2/HO-1.

Cognitive Impairment, Functional Outcome, and Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Measures such as modified Rankin Scale (mRS) may not reflect cognitive outcome following aneurysmal subarachnoid hemorrhage. The aim of this study was to assess the relationship between functional outcome, measured by mRS, and cognition, measured by mini-mental state examination (MMSE), after aSAH. A secondary analysis evaluated the impact of delayed cerebral ischemia (DCI) on the proportion of patients who had cognitive impairment.

METHODS

We performed a post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial data. MMSE and mRS scores were compared using Kruskal-Wallis equality-of-populations rank test with pairwise comparison post hoc analysis. Cognitive impairment was defined as MMSE score <27. A stepwise logistic regression model evaluated whether DCI was a predictor of cognitive impairment.

RESULTS

CONSCIOUS-1 comprised 413 patients. Of these, 337 took an MMSE at their 12-week follow-up. Mean MMSE score was 27 with a median of 29 (range, 0-30; SD 5.4). There were no significant differences between MMSE scores of patients who had 12-week mRS scores of 0-2. On multivariate analysis, DCI was independently associated with cognitive impairment after aSAH.

CONCLUSIONS

Patients considered to have a good outcome on mRS had varying degrees of cognitive function on MMSE, whereas development of DCI was an independent predictor of cognitive impairment after aSAH. MMSE may not be sensitive enough to discern subtle defects in cognition, as the median score was 29 out of 30.

Excessive release of endogenous neuropeptide Y into cerebrospinal fluid after treatment of spontaneous subarachnoid haemorrhage and its possible impact on self-reported neuropsychological performance - results of a prospective clinical pilot study on good-grade patients

OBJECTIVES

Neuropsychological dysfunction after treatment of spontaneous subarachnoid haemorrhage (sSAH) is common but underreported. The vasoconstrictor neuropeptide Y (NPY) is excessively released after sSAH and in psychiatric disorders. We prospectively analysed the treatment-specific differences in the secretion of endogenous cerebrospinal fluid (CSF) NPY during the acute stage after sSAH and its impact on cognitive processing.

METHODS

A total of 26 consecutive patients (f:m = 13:8; mean age 50.6 years) with good-grade sSAH were enrolled (drop out n = 5): n = 9 underwent endovascular aneurysm occlusion, n = 6 microsurgery, and n = 6 patients with perimesencephalic SAH received standardized intensive medical care. Ventricular CSF was drawn daily from day 1-10. CSF NPY levels were determined with competitive enzyme immunoassay. All patients underwent neuropsychological self-report assessment [36-Item Short Form Health Survey (SF-36) and ICD-10-Symptom-Rating questionnaire (ISR)] after the onset of sSAH (day 11-35; t₁) and at the 6-month follow-up (t₂).

RESULTS

At t₁, increased mean levels of NPY in CSF significantly correlated with impaired performance in most ISR scores (ISR total p = .018, depression p = .035, anxiety p = .008, nutrition disorder p = .047, supplementary items p = .038) and in several psychological SF-36 items (vitality p = .019, general mental health p = .001, mental component summary p = .025).

DISCUSSION

To the best of our knowledge, this study is the first to correlate the levels of endogenous NPY in supratentorial CSF with cognitive outcome in good-grade sSAH patients. Excessive NPY release into CSF may have a short-term influence on the pathogenesis of neuropsychological deficits. The impact of cerebrovascular manipulation on NPY release has to be further elucidated.

ABBREVIATIONS

ANOVA: analysis of variance; aSAH: aneurysmal subarachnoid haemorrhage; AUC: area under the curve; CBF: cerebral blood flow; CSF: cerebrospinal fluid; CT (scan): computed tomography (scan); CV: cerebral vasospasm; DIND: delayed ischemic neurological deficit; DSA: digital subtraction angiography; EIA: enzyme immunoassay; EV: endovascular aneurysm occlusion; EVD: external ventricular drainage; FU: 6-month follow-up; GCS: Glasgow Coma Scale; Ghp: general health perceptions; GOS: Glasgow Outcome Scale; h: hour/s; HH: Hunt and Hess; ICU: intensive care unit; ISR: ICD-10-Symptom-Rating questionnaire; MCS: mental component summary; Mhi: general mental health; min: minute/s; min-max: minimum - maximum; ml: millilitre; mRS: modified Ranking Scale; MS: microsurgical clipping, microsurgical aneurysm occlusion; ng: nanograms; no. [n]: number; NPY: Neuropeptide Y; p: p value; Pain: bodily pain; PCS: physical component summary; Pfi: physical functioning; pSAH: perimesencephalic subarachnoid haemorrhage; PTSD: posttraumatic stress disorder; QoL: quality of life; Rawhtran: health transition item; Rolem: role limitations because of emotional problems; Rolph: role limitations due to physical health problems; SAH: subarachnoid haemorrhage; SD: standard deviation; SF-36: 36-Item Short Form Health Survey; Social: social functioning; sSAH: spontaneous subarachnoid haemorrhage; TCD: trans-cranial Doppler ultrasound; (test) t₁: test in the sub-acute phase after the onset of bleeding (between day 11 and 35 after subarachnoid haemorrhage); (test) t₂: test in the short-term (chronic phase) after treatment at 6-month follow-up; test t₁ - t₂: intergroup development from t₁ to t₂; Vital: vitality; vs: versus.

Sex differences in delayed cerebral ischemia after subarachnoid hemorrhage

OBJECTIVE

In this study the authors sought to investigate the sex differences in the risk of delayed cerebral ischemia (DCI), delayed cerebral infarction, and the role of hormonal status.

METHODS

Ten studies included in the SAHIT (SAH International Trialists) repository were analyzed using a fitting logistic regression model. Heterogeneity between the studies was tested using I2 statistics, and the results were pooled using a random-effects model. Multivariable analysis was adjusted for the effects of neurological status and fixed effect of study. An additional model was examined in which women and men were split into groups according to an age cut point of 55 years, as a surrogate to define hormonal status.

RESULTS

A pooled cohort of 6713 patients was analyzed. The risk of DCI was statistically significantly higher in women than in men (OR 1.29, 95% CI 1.12–1.48); no difference was found with respect to cerebral infarction (OR 1.17, 95% CI 0.98–1.40). No difference was found in the risk of DCI when comparing women ≤ 55 and > 55 years (OR 0.87, 95% CI 0.74–1.02; p = 0.08) or when comparing men ≤ 55 and > 55 years (p = 0.38). Independent predictors of DCI were World Federation of Neurosurgical Societies (WFNS) grade, Fisher grade, age, and sex. Independent predictors of infarction included WFNS grade, Fisher grade, and aneurysm size.

CONCLUSIONS

Female sex is associated with a higher risk of DCI. Sex differences may play a role in the pathogenesis of DCI but are not associated with menopausal status. The predictors of DCI and cerebral infarction were identified in a very large cohort and reflect experience from multiple institutions.

Factors associated with clinical and radiological status on admission in patients with aneurysmal subarachnoid hemorrhage

Grading scales yield objective measure of the severity of aneurysmal subarachnoid hemorrhage and serve as to guide treatment decisions and for prognostication. The purpose of this cohort study was to determine what factors govern a patient's disease-specific admission scores in a representative Central European cohort. The Swiss Study of Subarachnoid Hemorrhage includes anonymized data from all tertiary referral centers serving subarachnoid hemorrhage patients in Switzerland. The 2009-2014 dataset was used to evaluate the impact of patient and aneurysm characteristics on the patients' status at admission using descriptive and multivariate regression analysis. The primary/co-primary endpoints were the GCS and the WFNS grade. The secondary endpoints were the Fisher grade, the presence of a thick cisternal or ventricular clot, the presence of a new focal neurological deficit or cranial nerve palsy, and the patient's intubation status. In our cohort of 1787 consecutive patients, increasing patient age by 10 years and low pre-ictal functional status (mRS 3-5) were inversely correlated with "high" GCS score (GCS ≥ 13) (OR 0.91, 95% CI 0.84-0.97 and OR 0.67, 95% CI 0.31-1.46), "low" WFNS grade (grade VI-V) (OR 1.21, 95% CI 1.04-1.20 and OR 1.47, 95% CI 0.66-3.27), and high Fisher grade (grade III-IV) (OR 1.08, 95% CI 1.00-1.17 and OR 1.54, 95% CI 0.55-4.32). Other independent predictors for the patients' clinical and radiological condition at admission were the ruptured aneurysms' location and its size. In sum, chronological age and pre-ictal functional status, as well as the ruptured aneurysm's location and size, determine the patients' clinical and radiological condition at admission to the tertiary referral hospital.

Spontaneous subarachnoid haemorrhage

Subarachnoid haemorrhage is an uncommon and severe subtype of stroke affecting patients at a mean age of 55 years, leading to loss of many years of productive life. The rupture of an intracranial aneurysm is the underlining cause in 85% of cases. Survival from aneurysmal subarachnoid haemorrhage has increased by 17% in the past few decades, probably because of better diagnosis, early aneurysm repair, prescription of nimodipine, and advanced intensive care support. Nevertheless, survivors commonly have cognitive impairments, which in turn affect patients' daily functionality, working capacity, and quality of life. Additionally, those deficits are frequently accompanied by mood disorders, fatigue, and sleep disturbances. Management requires specialised neurological intensive care units and multidisciplinary clinical expertise, which is better provided in high-volume centres. Many clinical trials have been done, but only two interventions are shown to improve outcome. Challenges that remain relate to prevention of subarachnoid haemorrhage by improved screening and development of lower-risk methods to repair or stabilise aneurysms that have not yet ruptured. Multicentre cooperative efforts might increase the knowledge that can be gained from clinical trials, which is often limited by small studies with differing criteria and endpoints that are done in single centres. Outcome assessments that incorporate finer assessment of neurocognitive function and validated surrogate imaging or biomarkers for outcome could also help to advance the specialty.

History of neurosurgery at University of Toronto: the St. Michael's story

In this paper, the authors describe the history of neurosurgery at St. Michael's Hospital, University of Toronto. St. Michael's has long been regarded as one of the top teaching and research hospitals in Canada. A detailed literature review of published and unpublished works was performed to formulate a succinct but in-depth review of its development, successes, and challenges. This fascinating 125-year history serves as a reminder of the importance of their institution's origins, and the authors hope that it will be a useful guide for developing programs around the world.

Loss of Consciousness at Onset of Aneurysmal Subarachnoid Hemorrhage is Associated with Functional Outcomes in Good-Grade Patients

BACKGROUND

Transient loss of consciousness (LOC) is one of the most common presentations of aneurysmal subarachnoid hemorrhage (SAH) and may be an indicator of early brain injury. In this study, we examined the association of LOC and functional outcomes in patients with good-grade SAH.

METHODS

We searched the Subarachnoid Hemorrhage International Trialists Repository for patients who presented with LOC at ictus of SAH. A propensity score analysis was performed on good-grade patients (defined as World Federation of Neurosurgical Societies grade 1-3) to balance selected covariates between those with and without LOC. The primary outcome was Glasgow Outcome Score (GOS) at 3 months (with poor outcome defined as a GOS of 1-3). Secondary outcomes were delayed cerebral ischemia (DCI), rebleed, length of hospital stay, and time to death.

RESULTS

A propensity score-matching algorithm identified 336 patients (168 with and 168 without LOC at ictus). The proportion of patients with poor functional outcome at 3 months was significantly higher in the cohort with LOC at ictus compared with the matched cohort without LOC at ictus (30% vs. 19%; P = 0.02). There was a nonsignificant trend toward greater mortality in the patients with LOC at ictus (19% vs. 13%; P = 0.14). There were no significant differences in the secondary outcomes between the 2 cohorts.

CONCLUSIONS

LOC at ictus of SAH is associated with a higher rate of unfavorable functional outcomes but not of mortality, DCI, or rebleed in patients with good-grade SAH. Future studies should further investigate the putative mechanisms through which LOC mediates early brain injury in SAH.

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 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.

Inhibition of the Receptor for Advanced Glycation End-Products (RAGE) Attenuates Neuroinflammation While Sensitizing Cortical Neurons Towards Death in Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a threatening and devastating neurological insult with high mortality and morbidity rates. Despite considerable efforts, the underlying pathophysiological mechanisms are still poorly understood. The receptor for advanced glycation end products (RAGE) is a multiligand receptor that has been implicated in various pathological conditions. We previously showed that RAGE was upregulated and may be involved in pathophysiology of SAH. In the current study, we investigated its potential role in SAH. We found that the upregulation of RAGE after SAH was NF-κB-dependent positive feedback regulation. Further, pharmacological inhibition of RAGE attenuated neuroinflammation, indicating a possible contributive role of RAGE in inflammation-associated brain injury after SAH. Conversely, however, inhibition of RAGE sensitized neurons, exacerbating cell death, which correlated with augmented apoptosis and diminished autophagy, suggesting that activation of RAGE may protect against SAH-induced neuronal injury. Furthermore, we demonstrate that inhibition of RAGE significantly reduced brain edema and improved neurological function at day 1 but not at day 3 post-SAH. Taken together, these results suggest that RAGE exerts dual role after SAH. Our findings also suggest caution should be exercised in setting RAGE-targeted treatment for SAH.

Neuroimaging characteristics of ruptured aneurysm as predictors of outcome after aneurysmal subarachnoid hemorrhage: pooled analyses of the SAHIT cohort

OBJECT Neuroimaging characteristics of ruptured aneurysms are important to guide treatment selection, and they have been studied for their value as outcome predictors following aneurysmal subarachnoid hemorrhage (SAH). Despite multiple studies, the prognostic value of aneurysm diameter, location, and extravasated SAH clot on computed tomography scan remains debatable. The authors aimed to more precisely ascertain the relation of these factors to outcome. METHODS The data sets of studies included in the Subarachnoid Hemorrhage International Trialists (SAHIT) repository were analyzed including data on ruptured aneurysm location and diameter (7 studies, n = 9125) and on subarachnoid clot graded on the Fisher scale (8 studies; n = 9452) for the relation to outcome on the Glasgow Outcome Scale (GOS) at 3 months. Prognostic strength was quantified by fitting proportional odds logistic regression models. Univariable odds ratios (ORs) were pooled across studies using random effects models. Multivariable analyses were adjusted for fixed effect of study, age, neurological status on admission, other neuroimaging factors, and treatment modality. The neuroimaging predictors were assessed for their added incremental predictive value measured as partial R(2). RESULTS Spline plots indicated outcomes were worse at extremes of aneurysm size, i.e., less than 4 or greater than 9 mm. In between, aneurysm size had no effect on outcome (OR 1.03, 95% CI 0.98-1.09 for 9 mm vs 4 mm, i.e., 75th vs 25th percentile), except in those who were treated conservatively (OR 1.17, 95% CI 1.02-1.35). Compared with anterior cerebral artery aneurysms, posterior circulation aneurysms tended to result in slightly poorer outcome in patients who underwent endovascular coil embolization (OR 1.13, 95% CI 0.82-1.57) or surgical clipping (OR 1.32, 95% CI 1.10-1.57); the relation was statistically significant only in the latter. Fisher CT subarachnoid clot burden was related to outcome in a gradient manner. Each of the studied predictors accounted for less than 1% of the explained variance in outcome. CONCLUSIONS This study, which is based on the largest cohort of patients so far analyzed, has more precisely determined the prognostic value of the studied neuroimaging factors. Treatment choice has strong influence on the prognostic effect of aneurysm size and location. These findings should guide the development of reliable prognostic models and inform the design and analysis of future prospective studies, including clinical trials.

Systematic review of clinical prediction tools and prognostic factors in aneurysmal subarachnoid hemorrhage

Background:

Clinical prediction tools assist in clinical outcome prediction. They quantify the relative contributions of certain variables and condense information that identifies important indicators or predictors to a targeted condition. This systematic review synthesizes and critically appraises the methodologic quality of studies that derive both clinical predictors and clinical predictor tools used to determine outcome prognosis in patients suffering from aneurysmal subarachnoid hemorrhage (SAH).

Methods:

This systematic review included prospective and retrospective cohort studies, and randomized controlled trials (RCTs) investigating prognostic factors and clinical prediction tools associated with determining the neurologic outcome in adult patients with aneurysmal SAH.

Results:

Twenty-two studies were included in this systemic review. Independent, confounding, and outcome variables were studied. Methodologic quality of individual studies was also analyzed. Included were 3 studies analyzing databases from RCTs, 8 prospective cohort studies, and 11 retrospective cohort studies. The most frequently retained significant clinical prognostic factors for long-term neurologic outcome prediction include age, neurological grade, blood clot thickness, and aneurysm size.

Conclusions:

Systematic reviews for clinical prognostic factors and clinical prediction tools in aneurysmal SAH face a number of methodological challenges. These include within and between study patient heterogeneity, regional variations in treatment protocols, patient referral biases, and differences in treatment, and prognosis viewpoints across different cultures.

Memantine Attenuates Delayed Vasospasm after Experimental Subarachnoid Hemorrhage via Modulating Endothelial Nitric Oxide Synthase

Delayed cerebral vasospasm is an important pathological feature of subarachnoid hemorrhage (SAH). The cause of vasospasm is multifactorial. Impairs nitric oxide availability and endothelial nitric oxide synthase (eNOS) dysfunction has been reported to underlie vasospasm. Memantine, a low-affinity uncompetitive N-methyl-d-aspartate (NMDA) blocker has been proven to reduce early brain injury after SAH. This study investigated the effect of memantine on attenuation of vasospasm and restoring eNOS functionality. Male Sprague-Dawley rats weighing 350–450 g were randomly divided into three weight-matched groups, sham surgery, SAH + vehicle, and SAH + memantine groups. The effects of memantine on SAH were evaluated by assessing the severity of vasospasm and the expression of eNOS. Memantine effectively ameliorated cerebral vasospasm by restoring eNOS functionality. Memantine can prevent vasospasm in experimental SAH. Treatment strategies may help combat SAH-induced vasospasm in the future.

Aspirin Inhibits Degenerative Changes of Aneurysmal Wall in a Rat Model

Aneurysmal subarachnoid hemorrhage still has a high mortality and morbidity despite notable advances in surgical approaches to cerebral aneurysm (CA). We examined the role of aspirin in vascular inflammation and degeneration. CA was induced in male Sprague-Dawley rats by ligating left common carotid artery and bilateral posterior renal arteries with or without aspirin treatment. The right anterior cerebral artery/olfactory artery (ACA/OA) bifurcations were stripped and assessed morphologically after Verhoeff's Van Gieson staining. Blood sample was obtained to examine circulating CD34(+) CD133(+) endothelial progenitor cells (EPCs), platelet aggregation and platelet counts. Macrophages infiltration in aneurysmal wall was evaluated by immunohistochemistry. Expression of matrix metalloproteinase-2 and 9 (MMP-2 and 9), nuclear factor kappa B (NF-κB), macrophage chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) was examined by RT-PCR. 2 months after CA induction, surgically treated rats manifested aneurysmal degeneration in ACA/OA bifurcations. Aspirin-treated rats exhibited a significant decrease in degradation of internal elastic lamina (IEL), medial layer thinning, CA size and macrophages infiltration with reduced expression of MMP-2 and 9 compared with rats in the CA group. RT-PCR demonstrated that the upregulation of NF-κB, MCP-1 and VCAM-1 after CA induction was reversed by aspirin treatment. Aspirin treatment following CA induction increased circulating EPCs to near control levels and reduced platelet aggregation without changing platelet counts. The evidence suggested that aspirin significantly reduced degeneration of aneurysm walls by inhibiting macrophages-mediated chronic inflammation and mobilizing EPCs.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vasospasm: my first 25 years-what worked? what didn't? what next?

Angiographic vasospasm as a complication of aneurysmal and other types of subarachnoid hemorrhage (SAH) was identified about 62 years ago. It is now hypothesized that angiographic vasospasm contributes to delayed cerebral ischemia (DCI) by multiple pathways, including reduced blood flow from angiographic vasospasm as well as microcirculatory constriction, microthrombosis, cortical spreading ischemia, and delayed effects of early brain injury. It is likely that other factors, such as systemic complications, effects of the subarachnoid blood, brain collateral and anastomotic blood flow, and the genetic and epigenetic makeup of the patient, contribute to the individual's response to SAH. Treatment of aneurysmal SAH and DCI includes neurocritical care management, early aneurysm repair, prophylactic administration of nimodipine, and rescue therapies (induced hypertension and balloon or pharmacologic angioplasty) if the patient develops DCI. Well-designed clinical trials of tirilazad, clasozentan, antiplatelet drugs, and magnesium have been conducted using more than a 1,000 patients each. Some of these drugs have almost purely vascular effects; other drugs are theoretically neuroprotective as well, but they share in common the ability to reduce angiographic vasospasm and, in many cases, DCI, but have no effect on clinical outcome. Experimental research in SAH continues to identify new targets for therapy. Challenges for the future will be to identify the most promising drugs to advance from preclinical studies and to understand why clinical trials have so frequently failed to show drug benefit on clinical outcome. Similar issues with treatment of ischemic stroke are being addressed by suggestions for improving the quality of experimental studies, collaborative preclinical trials, and multinational, multicenter clinical studies that can rapidly include many patients and be large enough to account for numerous factors that conspire to disrupt clinical trials.

Memantine alleviates brain injury and neurobehavioral deficits after experimental subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) causes brain injury via glutamate excitotoxicity, which leads to an excessive Ca(2+) influx and this starts an apoptotic cascade. Memantine has been proven to reduce brain injury in several types of brain insults. This study investigated the neuro-protective potential of memantine after SAH and explored the underlying mechanisms. An endovascular perforation rat model of SAH was used and Sprague-Dawley rats were randomized into sham surgery, SAH + vehicle, and SAH + memantine groups. The effects of memantine on SAH were evaluated by assessing the neuro-behavioral functions, blood-brain barrier (BBB) permeability and neuronal cell preservation. The mechanisms of action of memantine, with its N-methyl-D-aspartate (NMDA) antagonistic characteristics on nitric oxide synthase (NOS) expression and peroxynitrite formation, were also investigated. The apoptotic cascade after SAH was suppressed by memantine. Neuronal NOS (nNOS) expression, peroxynitrite formation, and subsequent oxidative/nitrosative stress were also reduced. Memantine effectively preserved BBB integrity, rescued neuronal injury, and improved neurological outcome in experimental SAH. Memantine has neuro-protective potential in experimental SAH and may help combat SAH-induced brain damage in the future.

Delayed neurological deterioration after subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) causes early brain injury (EBI) that is mediated by effects of transient cerebral ischaemia during bleeding plus effects of the subarachnoid blood. Secondary effects of SAH include increased intracranial pressure, destruction of brain tissue by intracerebral haemorrhage, brain shift, and herniation, all of which contribute to pathology. Many patients survive these phenomena, but deteriorate days later from delayed cerebral ischaemia (DCI), which causes poor outcome or death in up to 30% of patients with SAH. DCI is thought to be caused by the combined effects of angiographic vasospasm, arteriolar constriction and thrombosis, cortical spreading ischaemia, and processes triggered by EBI. Treatment for DCI includes prophylactic administration of nimodipine, and current neurointensive care. Prompt recognition of DCI and immediate treatment by means of induced hypertension and balloon or pharmacological angioplasty are considered important by many physicians, although the evidence to support such approaches is limited. This Review summarizes the pathophysiology of DCI after SAH and discusses established treatments for this condition. Novel strategies--including drugs such as statins, sodium nitrite, albumin, dantrolene, cilostazol, and intracranial delivery of nimodipine or magnesium--are also discussed.

Current practice in neuropsychological outcome reporting after aneurysmal subarachnoid haemorrhage

BACKGROUND

Neuropsychological deficits (NPD) are common in patients with aneurysmal subarachnoid haemorrhage (aSAH). NPD are one of the major limiting factors for patients with an otherwise acceptable prognosis for sustained quality of life. There are only a few studies reporting outcome after aSAH, which used a standardized neuropsychological test battery as a primary or secondary outcome measure. Aim of this study was to determine the current practice of reporting NPD following aSAH in clinical studies.

METHODS

A MEDLINE analysis was performed using the search term "subarachnoid haemorrhage outcome". The latest 1,000 articles were screened. We recorded study design, number of patients, and the presence of neuropsychological outcome report. Additionally, the time of testing after aSAH, the neuropsychological tests administered, as well as the percentage of patients with NPD were analyzed.

RESULTS

A total of 324 publications between 2009 and 2012 were selected for further review. Of those, 21 studies (6.5%) reported neuropsychological outcome, in 2,001 of 346,666 patients (0.6%). The assessment of NPD differed broadly using both subjective and objective cognitive evaluation, and a large variety of tests were used.

CONCLUSION

Neuropsychological outcome is underreported, and there is great variety in assessment in currently published clinical articles on aSAH. Prospective randomized trials treating aSAH may benefit from implementing more comprehensive and standardized neuropsychological outcome measures. This approach might identify otherwise unnoticed treatment effects in future interventional studies of aSAH patients.

Advancing care for traumatic brain injury: findings from the IMPACT studies and perspectives on future research

Research in traumatic brain injury (TBI) is challenging for several reasons; in particular, the heterogeneity between patients regarding causes, pathophysiology, treatment, and outcome. Advances in basic science have failed to translate into successful clinical treatments, and the evidence underpinning guideline recommendations is weak. Because clinical research has been hampered by non-standardised data collection, restricted multidisciplinary collaboration, and the lack of sensitivity of classification and efficacy analyses, multidisciplinary collaborations are now being fostered. Approaches to deal with heterogeneity have been developed by the IMPACT study group. These approaches can increase statistical power in clinical trials by up to 50% and are also relevant to other heterogeneous neurological diseases, such as stroke and subarachnoid haemorrhage. Rather than trying to limit heterogeneity, we might also be able to exploit it by analysing differences in treatment and outcome between countries and centres in comparative effectiveness research. This approach has great potential to advance care in patients with TBI.

Early MoCA-assessed cognitive impairment after aneurysmal subarachnoid hemorrhage and relationship to 1-year functional outcome

Recent clinical research into aneurysmal subarachnoid hemorrhage (aSAH) has confirmed the long-term effect of cognitive dysfunction on functional outcomes. We hypothesized that early cognitive impairment was a marker of permanent brain injury and hence predicted long-term functional outcome. Hong Kong Chinese patients with aneurysmal subarachnoid hemorrhage were evaluated prospectively by means of the Montreal Cognitive Assessment (MoCA) in the subacute phase (2-4 weeks after aSAH) and by neuropsychological evaluation of functional outcomes in the chronic phase (1 year after aSAH). This multi-center prospective observational study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). One hundred and eight patients completed both the subacute and chronic phase assessments. Cognitive dysfunction in the subacute phase independently correlated with functional outcomes at 1 year, after adjusting for age, admission clinical condition, treatment modality, motor score, and mobility in the subacute phase, but the positive predictive values remained low. MoCA-assessed cognitive impairment in the subacute phase cannot accurately predict functional outcomes at 1 year. Future study should focus on understanding the relative importance of different components of early cognitive impairment.