Clazosentan to overcome neurological ischemia and infarction occurring after subarachnoid hemorrhage (CONSCIOUS-1): randomized, double-blind, placebo-controlled phase 2 dose-finding trial

Nimodipine in Aneurysmal Subarachnoid Hemorrhage: Are Old Data Enough to Justify Its Current Treatment Regimen?

Nimodipine, a dihydropyridine L-type calcium channel antagonist, constitutes one of the mainstays of care to prevent delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage (aSAH) because it has been associated with a reduction in infarction rates and improvement in functional outcomes despite not significantly preventing angiographic vasospasm. Although it is a widely accepted treatment, controversies surrounding the current regimen of nimodipine in patients with aSAH exist. Still, there is a wide space open for randomized controlled trials or alternative study designs comparing different routes of administration, dosing, and timing of nimodipine treatment regimen in patients with aSAH.

Sirtuins as Potential Targets for Neuroprotection: Mechanisms of Early Brain Injury Induced by Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a prevalent cerebrovascular disease with significant global mortality and morbidity rates. Despite advancements in pharmacological and surgical approaches, the quality of life for SAH survivors has not shown substantial improvement. Traditionally, vasospasm has been considered a primary contributor to death and disability following SAH, but anti-vasospastic therapies have not demonstrated significant benefits for SAH patients' prognosis. Emerging studies suggest that early brain injury (EBI) may play a crucial role in influencing SAH prognosis. Sirtuins (SIRTs), a group of NAD + -dependent deacylases comprising seven mammalian family members (SIRT1 to SIRT7), have been found to be involved in neural tissue development, plasticity, and aging. They also exhibit vital functions in various central nervous system (CNS) processes, including cognition, pain perception, mood, behavior, sleep, and circadian rhythms. Extensive research has uncovered the multifaceted roles of SIRTs in CNS disorders, offering insights into potential markers for pathological processes and promising therapeutic targets (such as SIRT1 activators and SIRT2 inhibitors). In this article, we provide an overview of recent research progress on the application of SIRTs in subarachnoid hemorrhage and explore their underlying mechanisms of action.

Cilostazol Alleviates Delayed Cerebral Ischemia After Subarachnoid Hemorrhage by Attenuating Microcirculatory Dysfunction

Cilostazol, a phosphodiesterase 3 (PDE3) inhibitor that exerts antiplatelet effects, has therapeutic potential for delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). However, its mechanism of action remains unclear. We hypothesized that cilostazol alleviates DCI by improving cerebral microcirculatory dysfunction, which is a component of early brain injury. To test this hypothesis, we analyzed the intracerebral circulation time (iCCT) in 256 patients with aSAH from two randomized controlled trials (74 received cilostazol, 54 received pitavastatin, and 128 were controls). A minority of patients (n = 72, 28%) developed severe angiographic vasospasm (aVS) and DCI (n = 42, 16%) and had poor outcomes (n = 35, 14%). We measured iCCT as the time to peak in the ultraearly phase (baseline) and the subacute phase or at DCI onset (follow-up). The cilostazol group had shorter follow-up iCCT and larger iCCT differences than the other groups, indicating improved microcirculatory function, particularly in patients with DCI and poor outcomes. Multivariate analysis revealed that cilostazol treatment is a significant predictor of favorable outcomes, whereas DCI occurrence, a decrease in iCCT differences, and high clinical severity (Hunt & Hess grades 3-4) were associated with poor outcomes. Diminished microcirculatory dysfunction may alleviate DCI and improve outcomes among patients with aSAH following cilostazol treatment. Further research is warranted to confirm these findings and explore the dose-dependent effects of cilostazol on the microcirculatory function.

Delayed Internal Carotid Artery Dissection Mimicking Cerebral Vasospasms after Subarachnoid Hemorrhage: A Case Report

BACKGROUND

 Delayed cerebral ischemia (DCI) is usually caused by cerebral vasospasm (CVS). To detect DCI and CVS, a cranial computed tomography (CT) scan will be performed, but cervical vessels are not necessarily displayed.

METHODS

 A 63-year-old female patient who suffered from aneurysmal subarachnoid hemorrhage (SAH) was treated at the authors' institution. After an initially unremarkable clinical course, she developed aphasia on day 11. CT angiography (CTA) and perfusion imaging revealed significant hypoperfusion of the left hemisphere. In addition, the CTA showed a subtotal stenosis of the internal carotid artery (ICA) at the level of the petrous segment, suspicious for a dissection. This was not detectable angiographically in the final control of the intervention and was also not clinically evident until day 11.

RESULTS

 Cerebral perfusion as well as the clinical symptoms normalized rapidly after stent reconstruction of the ICA.

CONCLUSION

 Even though CVS is the most common cause of hypoperfusion in patients after an SAH, a peri-interventional dissection can also lead to relevant stenosis and thus to a disturbed cerebral perfusion and corresponding neurologic deficits. The time delay between the intervention and the clinical and CTA manifestation in our case is remarkable.

The Impact of Sedative Choice in the Management of Aneurysmal Subarachnoid Hemorrhage: A Scoping Review

Aneurysmal subarachnoid hemorrhage (aSAH) is characterized by high mortality and morbidity. This scoping review assesses the current evidence regarding the use of sedatives and analgesics in the acute intensive care unit management of aSAH. We conducted a systematic search of Ovid MEDLINE, Ovid Embase, Ovid EmCare, APA PsycInfo, CINAHL, and the Cochrane Database of Systematic Reviews from inception to June 2023. Studies were included if they enrolled intensive care unit patients aged 18 or older with a significant proportion (> 20%) who had aSAH and evaluated the impact of one or more commonly used analgosedatives on physiological parameters in the management of aSAH. The methodological quality of the studies was assessed using the Methodological Index for Nonrandomized Studies score. Of 2,583 articles, 11 met the inclusion criteria. The median sample size was 47 (interquartile range 10-127), and the median Methodological Index for Nonrandomized Studies score was 9.5 (interquartile range 8-11). The studies' publication years ranged from 1980 to 2023. Dexmedetomidine and ketamine showed potential benefits in reducing the incidence of cortical spreading depolarization and delayed cerebral ischemia. Propofol and opioids appeared safe but lacked robust evidence for efficacy. Benzodiazepines were associated with increased delayed cerebral ischemia-related cerebral infarctions and cortical spreading depolarization events. The evidence available to guide the use of analgosedative medications in aSAH is critically inadequate. Dexmedetomidine and ketamine warrant further exploration in large-scale prospective studies because of their potential benefits. Improved study designs with consistent definitions and a focus on patient-centered outcomes are necessary to inform clinical practice.

Prevention of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage-Summary of Existing Clinical Evidence

The 2023 International Subarachnoid Hemorrhage Conference identified a need to provide an up-to-date review on prevention methods for delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage and highlight areas for future research. A PubMed search was conducted for key factors contributing to development of delayed cerebral ischemia: anesthetics, antithrombotics, cerebrospinal fluid (CSF) diversion, hemodynamic, endovascular, and medical management. It was found that there is still a need for prospective studies analyzing the best methods for anesthetics and antithrombotics, though inhaled anesthetics and antiplatelets were found to have some advantages. Lumbar drains should increasingly be considered the first line of CSF diversion when applicable. Finally, maintaining euvolemia before and during vasospasm is recommended as there is no evidence supporting prophylactic spasmolysis or angioplasty. There is accumulating observational evidence, however, that intra-arterial spasmolysis with refractory DCI might be beneficial in patients not responding to induced hypertension. Nimodipine remains the medical therapy with the most support for prevention.

Volatile Sedation in Neurointensive Care Patients After Aneurysmal Subarachnoid Hemorrhage: Effects on Delayed Cerebral Ischemia, Cerebral Vasospasm, and Functional Outcome

BACKGROUND

Volatile anesthetics have shown neuroprotective effects in preclinical studies, but clinical data on their use after aneurysmal subarachnoid hemorrhage (aSAH) are limited. This study aimed to analyze whether the use of volatile anesthetics for neurocritical care sedation affects the incidence of delayed cerebral ischemia (DCI), cerebral vasospasm (CVS), DCI-related infarction, or functional outcome.

METHODS

Data were retrospectively collected for ventilated aSAH patients (2016-2022), who received sedation for at least 180 hours. For comparative analysis, patients were assigned to a control and a study group according to the sedation used (intravenous vs. volatile sedation). Logistic regression analysis was performed to identify independent predictors of DCI, CVS, DCI-related infarction, and functional outcome.

RESULTS

Ninety-nine patients with a median age of 58 years (interquartile range: 52-65 years) were included. Forty-seven patients (47%) received intravenous sedation, while 52 patients (53%) received (additional) volatile sedation with isoflurane (n = 30, 58%) or sevoflurane (n = 22, 42%) for a median duration of 169 hours (range: 5-298 hours). There were no significant differences between the 2 groups regarding the occurrence of DCI, angiographic CVS, DCI-related infarction, or functional outcome. In a multivariable logistic regression analysis, the use of volatile anesthetics had no impact on the incidence of DCI-related infarction or the patients' functional outcome.

CONCLUSIONS

Volatile sedation in aSAH patients is not associated with the incidence of DCI, CVS, DCI-related infarction, or functional outcome. Although we could not demonstrate neuroprotective effects of volatile anesthetics, our results suggest that volatile sedation after aSAH has no negative effect on the patient's outcome.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The effectiveness and safety of clazosentan in treating aneurysmal subarachnoid hemorrhage: A systematic review and meta-analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe event often complicated by cerebral vasospasm (CV). This study aimed to assess the efficacy and safety of clazosentan, an endothelin receptor antagonist, in reducing CV, delayed cerebral ischemia (DCI), and the need for rescue therapy in aSAH patients, while evaluating its impact on functional outcomes and mortality.

METHODS

We conducted a literature search across multiple databases to identify relevant studies evaluating the effects of clazosentan in aSAH patients. Both cohort studies and randomized controlled trials (RCTs) were included. The primary outcomes were vasospasm incidence, moderate to severe vasospasm, DCI, and the need for rescue therapy. Secondary outcomes included functional outcomes, mortality, and adverse events. The data were pooled as Risk ratios (R/R) with 95 % confidence intervals (CI) using RevMan 5.4 software.

RESULTS

A total of 11 studies, including 10 published and one unpublished, comprising 8,469 patients were included in the meta-analysis. Clazosentan significantly reduced the incidence of vasospasm (R/R = 0.49: 0.34-0.70), moderate to severe vasospasm (R/R = 0.53: 0.46-0.61), DCI (R/R = 0.70: 0.59-0.82), and the need for rescue therapy (R/R = 0.65: 0.52-0.83) compared to placebo. However, no significant improvement in functional outcomes or mortality rates was observed. Clazosentan was associated with increased rates of pulmonary adverse events (R/R = 1.89: 1.64-2.18), hypotension (R/R = 2.47: 1.79-3.42), and anemia (R/R = 1.49: 1.23-1.79) but no increased risk of hepatobiliary adverse events or cerebral hemorrhage.

CONCLUSIONS

Clazosentan demonstrates efficacy in reducing vasospasm, moderate to severe vasospasm, DCI, and the need for rescue therapy in aSAH patients, but does not significantly improve functional outcomes or mortality rates. While associated with specific adverse events, clazosentan may be a valuable adjunctive therapy in the management of aSAH, particularly in a high-risk population for vasospasm.

Outcomes Measures in Subarachnoid Hemorrhage Research

Despite advancements in acute management, morbidity rates for subarachnoid hemorrhage (SAH) remain high. Therefore, it is imperative to utilize standardized outcome scales in SAH research for evaluating new therapies effectively. This review offers a comprehensive overview of prevalent scales and clinical outcomes used in SAH assessment, accompanied by recommendations for their application and prognostic accuracy. Standardized terminology and diagnostic criteria should be employed when reporting pathophysiological outcomes such as symptomatic vasospasm and delayed cerebral ischemia. Furthermore, integrating clinical severity scales like the World Federation of Neurosurgical Societies scale and modified Fisher score into clinical trials is advised to evaluate their prognostic significance, despite their limited correlation with outcomes. The modified Rankin score is widely used for assessing functional outcomes, while the Glasgow outcome scale-extended version is suitable for broader social and behavioral evaluations. Avoiding score dichotomization is crucial to retain valuable information. Cognitive and behavioral outcomes, though frequently affected in patients with favorable neurological outcomes, are often overlooked during follow-up outpatient visits, despite their significant impact on quality of life. Comprehensive neuropsychological evaluations conducted by trained professionals are recommended for characterizing cognitive function, with the Montreal Cognitive Assessment serving as a viable screening tool. Additionally, integrating psychological inventories like the Beck Depression and Anxiety Inventory, along with quality-of-life scales such as the Stroke-Specific Quality of Life Scale, can effectively assess behavioral and quality of life outcomes in SAH studies.

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

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

The Effect of Age on Cerebral Vasospasm and Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The association between patient age and cerebral arterial vasospasm (CVS) and delayed cerebral ischemia (DCI) risk following aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. This study aims to assess the role of age on aSAH-related complications.

METHODS

Single-center retrospective study comprising aSAH patients treated between January 2009 and March 2023. Age was analyzed as continuous and categorical variables (<60 yrs vs. ≥60 yrs and by decade). Outcomes of interest included radiographic CVS, DCI, cerebral infarction, in-hospital mortality, length-of-stay (LOS), ventriculoperitoneal shunt placement, and modified Rankin Scale (mRS) scores at discharge and 3-month follow-up.

RESULTS

Nine hundred and twenty-five aSAH patients were included. Most (n = 598; 64.6%) were <60 yrs old (46 ± 9.1 yrs). CVS likelihood was lower in the older cohort (aOR = 0.56 [0.38-0.82]). Patients ≥60 yrs had higher mortality rates (aOR = 2.24 [1.12-4.47]) and worse mRS scores at discharge (aOR = 2.66 [1.91-3.72]) and 3-month follow-up (aOR = 2.19 [1.44-3.32]). Advanced age did not have a significant effect on DCI or cerebral infarction risk. Higher in-hospital mortality was documented with increasing age (P < 0.001). A significant interaction between CVS and age for the outcome of DCI was documented, with a stronger positive effect on poor outcomes (i.e., higher odds of DCI) among patients aged <60 years compared to those aged ≥60.

CONCLUSIONS

There is an inverse relationship between patient age and CVS incidence following aSAH. Nonetheless, patients ≥60 yrs had comparable DCI rates, higher in-hospital mortality, and worse functional outcomes than their younger counterparts. Routine screening and reliance on radiographic CVS as primary marker for aSAH-related complications should be reconsidered, particularly in older patients.

Protein kinase C-inhibition reduces critical weight loss and improves functional outcome after experimental subarachnoid haemorrhage

OBJECTIVES

Subarachnoid haemorrhage (SAH) carries a high burden of morbidity and mortality. One in three patients develop vasospasm, which is associated with Delayed Cerebral Ischemia. The pathophysiology includes vasoconstrictor receptor upregulation in cerebral arteries. The protein kinase C - inhibitor RO-31-7549 reduces the expression of several vasoconstrictor receptors and normalizes cerebral blood flow in experimental SAH but functional and behavioural effects are unknown. This study was undertaken to analyse functional outcomes up to 14 days after experimental SAH.

MATERIALS AND METHODS

54 male rats were randomised to experimental SAH or sham, using the pre-chiasmatic, single injection model, and subsequent treatment or vehicle. 42 remained for final analysis. The animals were euthanized on day 14 or when reaching a humane endpoint. The primary endpoint was overall survival, defined as either spontaneous mortality or when reaching a predefined humane endpoint. The secondary outcomes were differences in the rotating pole test, weight, open field test, novel object recognition and qPCR of selected inflammatory markers.

RESULTS

In the vehicle group 6/15 rats reached the humane endpoint of >20 % weight loss compared to 1/14 in the treatment group. This resulted in a significant reduced risk of early euthanasia due to >20 % weight loss of HR 0.15 (0.03-0.66, p = 0.04). Furthermore, the treatment group did significantly better on the rotating pole test, RR 0.64 (0.47-0.91, p = 0.02).

CONCLUSION

RO-31-7549 improved outcomes in terms >20 % weight loss and rotating pole performance after experimental SAH and could be investigated.

Prophylactic management of cerebral vasospasm with clazosentan in real clinical practice: a single-center retrospective cohort study

Introduction

Clazosentan, a selective endothelin receptor subtype A antagonist, reduces vasospasm-related morbidity and all-cause mortality following aneurysmal subarachnoid hemorrhage (SAH) in the Japanese population, as demonstrated by a recent randomized phase 3 trial. However, evidence to suggest clazosentan should be prioritized over the current standard of care to prevent cerebral vasospasm is still lacking. Therefore, we investigated the efficacy and safety of clazosentan in comparison with conventional postoperative management in real-world clinical practice.

Methods

We conducted a single-center, retrospective, observational cohort study using prospectively collected data from consecutive patients with aneurysmal SAH. After clazosentan was approved for use in Japan, the conventional postoperative management protocol, composed of intravenous fasudil chloride and oral cilostazol (control group, April 2021 to March 2022), was changed to the clazosentan protocol (clazosentan group, April 2022 to March 2023). The primary endpoint was the incidence of vasospasm-related symptomatic infarction. The secondary endpoints were favorable functional outcomes (modified Rankin scale score < 3) at discharge, angiographic vasospasm, and the need for rescue therapy for delayed cerebral ischemia.

Results

The analysis included 100 and 81 patients in the control and clazosentan groups, respectively. The incidence of vasospasm-related symptomatic infarction was significantly lower in the clazosentan group than in the control group (6.2% vs. 16%, p = 0.032). Multiple logistic analyses demonstrated that the use of clazosentan was independently associated with fewer incidence of vasospasm-related symptomatic infarct (23.8% vs. 47.5%, odds ratio 0.34 [0.12-0.97], p = 0.032). Clazosentan was significantly associated with favorable outcomes at discharge (79% vs. 66%, p = 0.037). Moreover, both the incidence of angiographic vasospasm (25.9% vs. 44%, p = 0.013) and the need for rescue therapy (16.1% vs. 34%, p = 0.006) was lower in the clazosentan group. The occurrence of pulmonary edema was significantly higher with clazosentan use (19.8% vs. 5%, p = 0.002), which did not result in morbidity.

Conclusion

A postoperative management protocol centering on clazosentan was associated with the reduced vasospasm-related symptomatic infarction and improved clinical outcomes compared to the conventional management protocol in Japanese clinical practice. Clazosentan might be a promising treatment option for counteracting cerebral vasospasm after aneurysmal SAH.

Utility of Surveillance Angiography in Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study of 223 Consecutive Patients

BACKGROUND

Patients with aneurysmal subarachnoid hemorrhage (aSAH) who survive the rupture are at risk for delayed neurologic deficits and cerebral infarction. The ideal method(s) of surveillance for cerebral vasospasm, and the link between radiographic vasospasm and delayed neurologic deficits, remain controversial. We instituted a postbleed day 7 angiography protocol with the stated goals of identification of vasospasm, improving neurologic outcomes, and possibly lowering cost of care.

METHODS

We conducted a quality improvement project in which we retrospectively analyzed consecutive cases of aSAH from a single institution over a 5-year period. Patients were excluded if they did not receive treatment for their aneurysm or were < 18 years of age. We analyzed demographic and outcome information for patients managed by protocolled angiography versus those who were managed by as-needed endovascular rescue therapy. Statistical tests were performed comparing means and proportions in both cohorts, as appropriate.

RESULTS

In total, 223 patients were identified who met inclusion criteria. In total, 157 patients were identified in the protocolled day 7 angiography group, and 66 were in the nonprotocolled angiography group. Demographics were similar between the day 7 angiogram and medical management cohorts, except for a higher mean age among the latter group (p = 0.016). The protocolled angiography group underwent a significantly greater number of angiograms (p < 0.001) and had a significantly higher cost of hospitalization ($240,327 vs. $205,719, p = 0.03), with no significant difference in rate of cerebral infarction, length of intensive care unit stay, length of hospital stay, discharge location, or discharge modified Rankin Score.

CONCLUSIONS

This cohort comparison analysis draws into question the practice of protocolized cerebral angiography in patients with aSAH.

Role of microglia after subarachnoid hemorrhage

Subarachnoid hemorrhage is a devastating sequela of aneurysm rupture. Because it disproportionately affects younger patients, the population impact of hemorrhagic stroke from subarachnoid hemorrhage is substantial. Secondary brain injury is a significant contributor to morbidity after subarachnoid hemorrhage. Initial hemorrhage causes intracranial pressure elevations, disrupted cerebral perfusion pressure, global ischemia, and systemic dysfunction. These initial events are followed by two characterized timespans of secondary brain injury: the early brain injury period and the delayed cerebral ischemia period. The identification of varying microglial phenotypes across phases of secondary brain injury paired with the functions of microglia during each phase provides a basis for microglia serving a critical role in both promoting and attenuating subarachnoid hemorrhage-induced morbidity. The duality of microglial effects on outcomes following SAH is highlighted by the pleiotropic features of these cells. Here, we provide an overview of the key role of microglia in subarachnoid hemorrhage-induced secondary brain injury as both cytotoxic and restorative effectors. We first describe the ontogeny of microglial populations that respond to subarachnoid hemorrhage. We then correlate the phenotypic development of secondary brain injury after subarachnoid hemorrhage to microglial functions, synthesizing experimental data in this area.

Gender differences in Alzheimer's may be associated with TLR4-LYN expression in damage associated microglia and neuronal phagocytosis

The role of Aβ plaques and neurofibrillary tangles in Alzheimer's disease (AD) pathogenesis have recently come into question due to failure of many pharmaceutical agents targeting these deposits and detection of these misfolded proteins in normal human brains. Therefore, we investigated correlations between microglial activation and toll like receptor 4 (TLR4) and Lck/Yes novel tyrosine (LYN) kinase signaling in an AD mouse model. In this study, we used 5-6-month-old 5XFAD and wild type (WT) male and female mice. Immunohistochemistry (IHC) and flow cytometry (FC) were performed on their brains. Cognitive performance was assessed with the Barnes-Maze. IHC showed more Ab aggregation in microglia of female 5XFAD mice compared to their male counterparts. Increased co-localization of microglial TLR4 and LYN was also observed in AD more than WT and females more than males. IHC also suggests microglial phagocytosis of neurons in AD mice, which is supported by FC data. Our FC data also support the involvement of disease associated microglia (DAMs) in this process based on cytokine secretion. Cognitive assessment by the Barnes maze showed 5XFAD females performed worse than males. In this study, we investigated the relationship between microglial TLR4 and LYN kinase in 5XFAD male and females. Our data reveals a correlation between microglial TLR4 and LYN co-localization and AD pathogenesis, more in females than males. Targeting microglial TLR4 and Lyn in DAMs may offer new therapeutic opportunities in the treatment of AD.

Clinical Outcome Prediction of Early Brain Injury in Aneurysmal Subarachnoid Hemorrhage: the SHELTER-Score

BACKGROUND

Despite intensive research on preventing and treating vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage (aSAH), mortality and morbidity rates remain high. Early brain injury (EBI) has emerged as possibly the major significant factor in aSAH pathophysiology, emphasizing the need to investigate EBI-associated clinical events for improved patient management and decision-making. This study aimed to identify early clinical and radiological events within 72 h after aSAH to develop a conclusive predictive EBI score for clinical practice.

METHODS

This retrospective analysis included 561 consecutive patients with aSAH admitted to our neurovascular center between 01/2014 and 09/2022. Fourteen potential predictors occurring within the initial 72 h after hemorrhage were analyzed. The modified Rankin Scale (mRS) score at 6 months, discretized to three levels (0-2, favorable; 3-5, poor; 6, dead), was used as the outcome variable. Univariate ordinal regression ranked predictors by significance, and forward selection with McFadden's pseudo-R2 determined the optimal set of predictors for multivariate proportional odds logistic regression. Collinear parameters were excluded, and fivefold cross-validation was used to avoid overfitting.

RESULTS

The analysis resulted in the Subarachnoid Hemorrhage Associated Early Brain Injury Outcome Prediction score (SHELTER-score), comprising seven clinical and radiological events: age (0-4 points), World Federation of Neurosurgical Societies (0-2.5 points), cardiopulmonary resuscitation (CPR) (2 points), mydriasis (1-2 points), midline shift (0.5-1 points), early deterioration (1 point), and early ischemic lesion (2 points). McFadden's pseudo-R2 = 0.339, area under the curve for death or disability 0.899 and 0.877 for death. A SHELTER-score below 5 indicated a favorable outcome (mRS 0-2), 5-6.5 predicted a poor outcome (mRS 3-5), and ≥ 7 correlated with death (mRS 6) at 6 months.

CONCLUSIONS

The novel SHELTER-score, incorporating seven clinical and radiological features of EBI, demonstrated strong predictive performance in determining clinical outcomes. This scoring system serves as a valuable tool for neurointensivists to identify patients with poor outcomes and guide treatment decisions, reflecting the great impact of EBI on the overall outcome of patients with aSAH.

Comparison of efficacy between clazosentan and fasudil hydrochloride-based management of vasospasm after subarachnoid hemorrhage focusing on older and WFNS grade V patients: a single-center experience in Japan

Subarachnoid hemorrhage often leads to poor outcomes owing to vasospasm, even after successful aneurysm treatment. Clazosentan, an endothelin receptor inhibitor, has been proven to be an effective treatment for vasospasms in a Japanese randomized controlled trial. However, its efficacy in older patients (≥ 75 years old) and those with World Federation of Neurosurgical Societies (WFNS) grade V has not been demonstrated. We retrospectively evaluated the efficacy of clazosentan in older patients and those with WFNS grade V, using real-world data. Patients with subarachnoid hemorrhage treated before and after the introduction of clazosentan were retrospectively evaluated. The patients were categorized into two groups (clazosentan era versus pre-clazosentan era), in which vasospasm management and outcomes were compared. Vasospasms were managed with fasudil hydrochloride-based (pre-clazosentan era) or clazosentan-based treatment (clazosentan era). Seventy-eight patients were included in this study: the clazosentan era (n = 32) and pre-clazosentan era (n = 46). Overall, clazosentan significantly reduced clinical vasospasms (clazosentan era: 31.3% versus pre-clazosentan era: 60.9%, p = 0.01), delayed cerebral ischemia (DCI) (9.4% versus 39.1%, p = 0.004), and vasospasm-related morbidity and mortality (M/M) (3.1% versus 19.6%, p = 0.03). In subgroup analysis of older patients or those with WFNS grade V, no significant difference was observed in clinical outcomes, although both DCI and vasospasm-related M/M were lower in the clazosentan era. Clazosentan was more effective than fasudil-based management in preventing DCI and reducing vasospasm-related M/M. Clazosentan could be used safely in older patients and those with WFNS grade V, although clinical outcomes in these patients were comparable to those of conventional treatment.

Pharmacological Prevention of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH) include early brain injury and delayed neurologic deterioration, which may result from delayed cerebral ischemia (DCI). Complex pathophysiological mechanisms underlie DCI, which often includes angiographic vasospasm (aVSP) of cerebral arteries.

METHODS

Despite the study of many pharmacological therapies for the prevention of DCI in aSAH, nimodipine-a dihydropyridine calcium channel blocker-remains the only drug recommended universally in this patient population. A common theme in the research of preventative therapies is the use of promising drugs that have been shown to reduce the occurrence of aVSP but ultimately did not improve functional outcomes in large, randomized studies. An example of this is the endothelin antagonist clazosentan, although this agent was recently approved in Japan.

RESULTS

The use of the only approved drug, nimodipine, is limited in practice by hypotension. The administration of nimodipine and its counterpart nicardipine by alternative routes, such as intrathecally or formulated as prolonged release implants, continues to be a rational area of study. Additional agents approved in other parts of the world include fasudil and tirilazad.

CONCLUSIONS

We provide a brief overview of agents currently being studied for prevention of aVSP and DCI after aSAH. Future studies may need to identify subpopulations of patients who can benefit from these drugs and perhaps redefine acceptable outcomes to demonstrate impact.

Cardiopulmonary Events of the Elderly (≥75 Years) during Clazosentan Therapy after Subarachnoid Hemorrhage: A Retrospective Study from a Tertiary Stroke Center in Japan

Clazosentan has been shown to prevent vasospasm and reduce mortality in patients after aneurysmal subarachnoid hemorrhage (SAH) and has been approved for clinical use in Japan; however, its systemic events in the elderly (aged ≥ 75 years) have not been well-documented. Here, we report serious/intolerable cardiopulmonary complications requiring discontinuation of drug therapy in elderly SAH patients. In this single-center case series study, medical records of consecutive SAH patients treated postoperatively with clazosentan (10 mg/h) between June 2022 and May 2023 were reviewed retrospectively. Thirty-three patients received clazosentan therapy, of whom six were elderly with a mean age of 80.3 ± 5.2 (range 75-89) years. Among them, despite no obvious medical history of systemic abnormalities, clazosentan was discontinued in three (50%) patients due to pleural effusion and hypoxemia with or without hypotension at 5 ± 3 days after therapy initiation, which was higher than the incidence for younger patients (15%). The elderly patients had significantly lower urine output (1935 ± 265 vs. 1123 ± 371 mL/day, p = 0.03) and greater weight gain (2.1 ± 1.1 vs. 4.2 ± 1.9 kg from baseline, p = 0.04) than patients who completed the therapy. One 89-year-old female developed congestive heart failure and hydrostatic pulmonary edema associated with increased intravascular and lung volumes even after therapy was discontinued, while the remaining two cases recovered within 2 days after drug cessation. These results suggest that elderly patients are more vulnerable to fluid retention and have a higher risk of cardiopulmonary complications during clazosentan therapy than younger patients. Careful monitoring of urine volume and weight gain and caution regarding age- and therapy-related hemodynamic insufficiencies are required.

Effect of Intrathecal Urokinase Infusion on Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Vasospasm following an aneurysmal subarachnoid hemorrhage (SAH) causes serious neurological complications, despite surgical clipping of the aneurysm. Intrathecal urokinase (UK) infusion has been shown to effectively prevent symptomatic vasospasm in patients who have undergone endovascular obliteration of the ruptured aneurysms.

OBJECTIVE

To investigate whether intrathecal UK infusion can prevent symptomatic vasospasm in patients undergoing surgical or endovascular treatment.

METHODS

A total of 90 patients with severe aneurysmal SAH were enrolled and assigned to a surgical neck clipping (n = 56) or an endovascular coil embolization (n = 34) groups. After treatment, UK infusion from the lumbar drain was repeated in 32 patients in the surgical neck clipping group (group B) and all in the endovascular coil embolization group (group C) until complete resolution of the SAH was observed on computed tomography. The remaining 24 of the surgical neck clipping group, without UK infusion, were assigned to group A.

RESULTS

Symptomatic vasospasm occurred in 7 (29.2%) patients in group A, 2 (6.3%) in group B, and none in group C (group A vs. group B [P = 0.02]; group B vs. group C [P = 0.14]). Excellent clinical outcomes (modified Rankin score, 0 or 1) were observed in 37.5%, 59.4%, and 76.5% of patients in group A, B, and C, respectively (group A vs. group B [P = 0.11]).

CONCLUSION

Clearance of SAH via intrathecal UK infusion significantly reduced symptomatic vasospasm in patients in both UK groups, resulting in better clinical outcomes.

Emerging Treatments for Subarachnoid Hemorrhage

The current landscape of therapeutic strategies for subarachnoid hemorrhage (SAH), a significant adverse neurological event commonly resulting from the rupture of intracranial aneurysms, is rapidly evolving. Through an in-depth exploration of the natural history of SAH, historical treatment approaches, and emerging management modalities, the present work aims to provide a broad overview of the shifting paradigms in SAH care. By synthesizing the historical management protocols with contemporary therapeutic advancements, patient-specific treatment plans can be individualized and optimized to deliver outstanding care for the best possible SAH-related outcomes.

Preventing Fluid Retention After Subarachnoid Haemorrhage During Administration of Endothelin Receptor Antagonist

Prevention of delayed cerebral infarction (DCI) due to cerebral vasospasm after subarachnoid haemorrhage (SAH) has been done with intravenous Rho kinase inhibitors (ROCKI), ozagrel sodium (TXA2I), selective ROCKI infusion (ROCKI i.a.), and cerebrospinal fluid (CSF) drainage. The endothelin receptor antagonist (ERA, clazosentan) became available in 2022 and is said to be highly recommended for DCI prevention, while fluid retention such as pleural effusion and pulmonary oedema accumulation is often experienced. We investigated the relationship between patient background, fluid retention, and ERA. Ten consecutive SAH patients treated with ERA from July to December 2022 were included. We examined the results of blood sampling on admission, echocardiography, chest computed tomography (CT), with postoperative DCI, and hydrocephalus requiring cerebrospinal fluid shunt (hydro), and symptomatic fluid retention requiring albumin and furosemide (third fluid space). Two males and eight females, mean age 63 years, mean preoperative World Federation Neurosurgical Surgeons (WFNS) grade 3.5, mean creatinine 0.94, mean brain natriuretic peptide (NT-proBNP). In 1883, two patients with Takotsubo cardiomyopathy and four patients with neurogenic pulmonary oedema are present. All patients underwent coil embolisation, and postoperative CSF drainage, ROCKI, TXA2I systemic administration, and ROCKI i.a. There were one DCI, three hydro, and five third fluid cases. Concerning the third fluid, the only significant difference was found in the age. An improvement in fluid retention after ERA discontinuation in old patients was shown. Our experience suggests that age may be the most influential factor. Based on these results, we have also found that by avoiding the use of ERA in patients older than 80 years, strictly limiting the infusion volume when using ERA, and actively using the drugs for heart failure early on, the frequency of suffering from third fluid space is reduced.

Connection between oxidative stress and subcellular organelle in subarachnoid hemorrhage: Novel mechanisms and therapeutic implications

Spontaneous subarachnoid hemorrhage (SAH) is one of the most devastating forms of stroke, with limited treatment modalities and poor patient outcomes. Previous studies have proposed multiple prognostic factors; however, relative research on treatment has not yet yielded favorable clinical outcomes. Moreover, recent studies have suggested that early brain injury (EBI) occurring within 72 h after SAH may contribute to its poor clinical outcomes. Oxidative stress is recognized as one of the main mechanisms of EBI, which causes damage to various subcellular organelles, including the mitochondria, nucleus, endoplasmic reticulum (ER), and lysosomes. This could lead to significant impairment of numerous cellular functions, such as energy supply, protein synthesis, and autophagy, which may directly contribute to the development of EBI and poor long-term prognostic outcomes. In this review, the mechanisms underlying the connection between oxidative stress and subcellular organelles after SAH are discussed, and promising therapeutic options based on these mechanisms are summarized.

Efficacy and Safety of Clazosentan After Aneurysmal Subarachnoid Hemorrhage: An Updated Meta-Analysis

BACKGROUND AND OBJECTIVES

Clazosentan has been studied to treat cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH).This meta-analysis of randomized controlled trials updates the current knowledge regarding the efficacy and safety of clazosentan compared with placebo after aSAH.

METHODS

Databases were systematically searched for randomized controlled trials directly comparing the use of clazosentan and placebo for the treatment of cerebral vasospasm after aSAH. Additional eligibility criteria were the report of any of the outcomes of interest (vasospasm, morbidity, functional outcome, or mortality). The primary outcome was vasospasm-related delayed cerebral ischemia (DCI). The analyses were stratified by clazosentan dosage (low or high dose) and aneurysm treatment modality (clipping or coiling). The Cochrane RoB-2 tool was used for studies quality assessment.

RESULTS

Six studies comprising 7 clinical trials were included, involving 2778 patients. Clazosentan decreased the risk of vasospasm-related DCI (risk ratio [RR] 0.56, 95% CI 0.38-0.81) and delayed ischemic neurological deficit (RR 0.63, 95% 0.50-0.80). Angiographic vasospasm (RR 0.54, 95% CI 0.47-0.61) was also decreased. Functional outcomes (favorable Glasgow Outcome Scale, RR 0.99, 95% CI 0.79-1.24) and death (RR 1.03, 95% CI 0.71-1.49) did not change. Meanwhile, adverse events were increased by clazosentan (RR 1.54, 95% CI 1.35-1.76).

CONCLUSION

Clazosentan decreased vasospasm-related DCI and angiographic vasospasm but did not improve functional outcomes or mortality. Adverse events were increased by clazosentan.

Percutaneous cervical sympathetic block to treat cerebral vasospasm and delayed cerebral ischemia: a review of the evidence

Delayed cerebral ischemia (DCI) affects 30% of patients following aneurysmal subarachnoid hemorrhage (aSAH) and is a major driver of morbidity, mortality, and intensive care unit length of stay for these patients. DCI is strongly associated with cerebral arterial vasospasm, reduced cerebral blood flow and cerebral infarction. The current standard treatment with intravenous or intra-arterial calcium channel antagonist and balloon angioplasty or stent has limited efficacy. A simple treatment such as a cervical sympathetic block (CSB) may be an effective therapy but is not routinely performed to treat vasospasm/DCI. CSB consists of injecting local anesthetic at the level of the cervical sympathetic trunk, which temporarily blocks the innervation of the cerebral arteries to cause arterial vasodilatation. CSB is a local, minimally invasive, low cost and safe technique that can be performed at the bedside and may offer significant advantages as complementary treatment in combination with more conventional neurointerventional surgery interventions. We reviewed the literature that describes CSB for vasospasm/DCI prevention or treatment in humans after aSAH. The studies outlined in this review show promising results for a CSB as a treatment for vasospasm/DCI. Further research is required to standardize the technique, to explore how to integrate a CSB with conventional neurointerventional surgery treatments of vasospasm and DCI, and to study its long-term effect on neurological outcomes.

Current and future strategies for targeting the endothelin pathway in cardiovascular disease

The first endothelin (ET)-1 receptor antagonist was approved for clinical use over 20 years ago, but to date this class of compounds has been limited to treating pulmonary arterial hypertension, a rare disease. Translational research over the last 5 years has reignited interest in the ET system as a therapeutic target across the spectrum of cardiovascular diseases including resistant hypertension, microvascular angina and post-coronavirus disease 2019 conditions. Notable developments include approval of a new ETA receptor antagonist and, intriguingly, combining the actions of ETA and an angiotensin II type 1 receptor antagonist within the same novel small molecule. Combinations of ET receptor blockers with other drugs, including phosphodiesterase-5 inhibitors and sodium-glucose co-transporter-2 antagonists, may drive synergistic benefits with the prospect of alleviating side effects. These new therapeutic strategies have the potential to dramatically widen the scope of indications targeting the ET-1 pathway.

Chronological Change of the Clinical Features and Treatment Outcomes for Subarachnoid Hemorrhage in Japan: A Multicenter Retrospective Study

Aneurysmal subarachnoid hemorrhage (SAH) treatment has progressed, and patients are rapidly aging in Japan. Consequently, dynamic changes must have emerged in the clinical practice of SAH. This study aimed to elucidate chronological changes of aneurysmal SAH and the prognostic factors in the previous quarter century in Japan. We conducted a retrospective survey regarding aneurysmal SAH in eight institutions in Japan. The study included 848, 863, and 781 patients in the first (1989-1993), second (1999-2003), and third (2009-2013) periods, respectively. The chronological changes of factors that influenced the poor outcomes and differences between the nonelderly (<75 years) and elderly patients were investigated. Mean age was significantly higher in patients in the third period (61.4 years) than in those in the other two periods (first, 57.8 years; second, 59.5 years). During these periods, the proportion of good outcomes did not change; however, the mortality rate significantly decreased from 19% in the first period to 11% and 9.2% in the second and third periods, respectively. The poor outcome was mainly caused by the significantly higher incidence of systemic complication and procedural complication in the first period and the significantly lower incidence of delayed ischemic neurological deficit in the third period. The elderly patients had significantly poorer clinical outcomes than the nonelderly ones. During the last 25 years, the age of patients with aneurysmal SAH has rapidly increased. The study results may contribute to the improvement of the treatment strategy of SAH in advanced countries with a rapidly aging population.

Clinical Grading Scales and Neuroprognostication in Acute Brain Injury

Prediction of neurological clinical outcome after acute brain injury is critical because it helps guide discussions with patients and families and informs treatment plans and allocation of resources. Numerous clinical grading scales have been published that aim to support prognostication after acute brain injury. However, the development and validation of clinical scales lack a standardized approach. This in turn makes it difficult for clinicians to rely on prognostic grading scales and to integrate them into clinical practice. In this review, we discuss quality measures of score development and validation and summarize available scales to prognosticate outcomes after acute brain injury. These include scales developed for patients with coma, cardiac arrest, ischemic stroke, nontraumatic intracerebral hemorrhage, subarachnoid hemorrhage, and traumatic brain injury; for each scale, we discuss available validation studies.

Diagnosis of Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage and Triggers for Intervention

INTRODUCTION

Delayed cerebral ischemia (DCI) is a major determinant for poor neurological outcome after aneurysmal subarachnoid hemorrhage (aSAH). Detection and treatment of DCI is a key component in the neurocritical care of patients with aSAH after initial aneurysm repair.

METHODS

Narrative review of the literature.

RESULTS

Over the past 2 decades, there has been a paradigm shift away from macrovascular (angiographic) vasospasm as a main diagnostic and therapeutic target. Instead, the pathophysiology of DCI is hypothesized to derive from several proischemic pathomechanisms. Clinical examination remains the most reliable means for monitoring and treatment of DCI, but its value is limited in comatose patients. In such patients, monitoring of DCI is usually based on numerous neurophysiological and/or radiological diagnostic modalities. Catheter angiography remains the gold standard for the detection of macrovascular spasm. Computed tomography (CT) angiography is increasingly used instead of catheter angiography because it is less invasive and may be combined with CT perfusion imaging. CT perfusion permits semiquantitative cerebral blood flow measurements, including the evaluation of the microcirculation. It may be used for prediction, early detection, and diagnosis of DCI, with yet-to-prove benefit on clinical outcome when used as a screening modality. Transcranial Doppler may be considered as an additional noninvasive screening tool for flow velocities in the middle cerebral artery, with limited accuracy in other cerebral arteries. Continuous electroencephalography enables detection of early signs of ischemia at a reversible stage prior to clinical manifestation. However, its widespread use is still limited because of the required infrastructure and expertise in data interpretation. Near-infrared spectroscopy, a noninvasive and continuous modality for evaluation of cerebral blood flow dynamics, has shown conflicting results and needs further validation. Monitoring techniques beyond neurological examinations may help in the detection of DCI, especially in comatose patients. However, these techniques are limited because of their invasive nature and/or restriction of measurements to focal brain areas.

CONCLUSION

The current literature review underscores the need for incorporating existing modalities and developing new methods to evaluate brain perfusion, brain metabolism, and overall brain function more accurately and more globally.

Novel Insights into Pathophysiology of Delayed Cerebral Ischemia: Effects of Current Rescue Therapy on Microvascular Perfusion Heterogeneity

General microvascular perfusion and its heterogeneity are pathophysiological features of delayed cerebral ischemia (DCI) that are gaining increasing attention. Recently, CT perfusion (CTP) imaging has made it possible to evaluate them radiologically using mean transit time (MTT) and its heterogeneity (measured by cvMTT). This study evaluates the effect of multimodal rescue therapy (intra-arterial nimodipine administration and elevation of blood pressure) on MTT and cvMTT during DCI in aneurysmal subarachnoid haemorrhage (aSAH) patients. A total of seventy-nine aSAH patients who underwent multimodal rescue therapy between May 2012 and December 2019 were retrospectively included in this study. CTP-based perfusion impairment (MTT and cvMTT) on the day of DCI diagnosis was compared with follow-up CTP after initiation of combined multimodal therapy. The mean MTT was significantly reduced in the follow-up CTP compared to the first CTP (3.7 ± 0.7 s vs. 3.3 ± 0.6 s; p < 0.0001). However, no significant reduction of cvMTT was observed (0.16 ± 0.06 vs. 0.15 ± 0.06; p = 0.44). Mean arterial pressure was significantly increased between follow-up and first CTP (98 ± 17 mmHg vs. 104 ± 15 mmHg; p < 0.0001). The combined multimodal rescue therapy was effective in addressing the general microvascular perfusion impairment but did not affect the mechanisms underlying microvascular perfusion heterogeneity. This highlights the need for research into new therapeutic approaches that also target these pathophysiological mechanisms of DCI.

A network meta-analysis of therapeutic and prophylactic management of vasospasm on aneurysmal subarachnoid hemorrhage outcomes

Background

Vasospasm and cerebral ischemia after aneurysmal subarachnoid hemorrhage are associated with mortality and poor neurological outcomes. We studied the efficacy of all available strategies targeting vasospasm and cerebral ischemia on outcomes in a network meta-analysis.

Methods

We searched EMBASE and MEDLINE databases from 1 January 1990 and 28 November 2021 according to PRISMA guidelines. Randomized controlled trials and longitudinal studies were included. All curative or preventive strategies targeting vasospasm and/or cerebral ischemia were eligible. A network meta-analysis was performed to compare all interventions with one another in a primary (randomized controlled trials only) and a secondary analysis (both trials and longitudinal studies). Mortality by 3 months was the primary outcome. Secondary outcomes were vasospasm, neurological outcome by 3 months, and dichotomized as "good" or "poor" recovery according to each study definition.

Results

A total of 2,382 studies were screened which resulted in the selection of 192 clinical trials (92 (47.9%) and 100 cohorts (52.1%) and the inclusion of 41,299 patients. In randomized controlled studies, no strategy decreased mortality by 3 months. Statins (0.79 [0.62-1]), tirilazad (0.82 [0.69-0.97]), CSF drainage (0.47 [0.29-0.77]), and clazosentan (0.51 [0.36-0.71]) significantly decreased the incidence of vasospasm. Cilostazol was the only treatment associated with improved neurological outcomes by 3 months in the primary (OR 1.16, 95% CI [1.05-1.28]) and secondary analyses (OR 2.97, 95% CI [1.39-6.32]).

Discussion

In the modern era of subarachnoid hemorrhage, all strategies targeting vasospasm failed to decrease mortality. Cilostazol should be confirmed as a treatment to improve neurological outcomes. The link between vasospasm and neurological outcome appears questionable.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=116073, identifier: PROSPERO CRD42018116073.

Real-world data of clazosentan in combination therapy for aneurysmal subarachnoid hemorrhage: a multicenter retrospective cohort study

Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm, significantly associated with morbidity and mortality. In double-blind, placebo-controlled phase 3 studies, clazosentan reduces cerebral vasospasm-related morbidity and all-cause mortality in patients with aSAH. There are no reports about the clinical efficacy of clazosentan combination therapy with some other drugs. Initially, we explored the efficacy of clazosentan combination therapy with cilostazol, statin, and antiepileptic drugs. Subsequently, we assessed the add-on effect of fasudil to clazosentan combination therapy for aSAH patients. This multicenter, retrospective, observational cohort study included Japanese patients with aSAH between June 2022 and March 2023. The primary outcome was the ordinal score on the modified Rankin Scale (mRS; range, 0-6, with elevated scores indicating greater disability) at discharge. Among the 47 cases (women 74.5%; age 64.4 ± 15.0 years) undergoing clazosentan combination therapy, 29 (61.7%) resulted in favorable outcomes. Overall, vasospasm occurred in 16 cases (34.0%), with four cases (8.5%) developing vasospasm-related delayed cerebral ischemia (DCI). Both hypotension and vasospasm-related DCI were related to unfavorable outcome at discharge. Fasudil were added in 18 (38.3%) cases. Despite adding fasudil to clazosentan combination therapy, the incidence of aSAH-related vasospasm did not decrease. Added-on fasudil to combination therapy related to pulmonary edema, vasospasm, and vasospasm-related DCI, and unfavorable outcomes. Clazosentan combination therapy could potentially result in favorable outcomes for aSAH patients to prevent post-aSAH vasospasm-related DCI. The add-on effect of fasudil to combination therapy did not demonstrate a significant impact in reducing aSAH-related vasospasm or improving outcomes at discharge.

Candidate neuroinflammatory markers of cerebral autoregulation dysfunction in human acute brain injury

The loss of cerebral autoregulation (CA) is a common and detrimental secondary injury mechanism following acute brain injury and has been associated with worse morbidity and mortality. However patient outcomes have not as yet been conclusively proven to have improved as a result of CA-directed therapy. While CA monitoring has been used to modify CPP targets, this approach cannot work if the impairment of CA is not simply related to CPP but involves other underlying mechanisms and triggers, which at present are largely unknown. Neuroinflammation, particularly inflammation affecting the cerebral vasculature, is an important cascade that occurs following acute injury. We hypothesise that disturbances to the cerebral vasculature can affect the regulation of CBF, and hence the vascular inflammatory pathways could be a putative mechanism that causes CA dysfunction. This review provides a brief overview of CA, and its impairment following brain injury. We discuss candidate vascular and endothelial markers and what is known about their link to disturbance of the CBF and autoregulation. We focus on human traumatic brain injury (TBI) and subarachnoid haemorrhage (SAH), with supporting evidence from animal work and applicability to wider neurologic diseases.

Resolution of Cerebral Inflammation Following Subarachnoid Hemorrhage

BACKGROUND

Aneurismal subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke that, despite improvement through therapeutic interventions, remains a devastating cerebrovascular disorder that has a high mortality rate and causes long-term disability. Cerebral inflammation after SAH is promoted through microglial accumulation and phagocytosis. Furthermore, proinflammatory cytokine release and neuronal cell death play key roles in the development of brain injury. The termination of these inflammation processes and restoration of tissue homeostasis are of utmost importance regarding the possible chronicity of cerebral inflammation and the improvement of the clinical outcome for affected patients post SAH. Thus, we evaluated the inflammatory resolution phase post SAH and considered indications for potential tertiary brain damage in cases of incomplete resolution.

METHODS

Subarachnoid hemorrhage was induced through endovascular filament perforation in mice. Animals were killed 1, 7 and 14 days and 1, 2 and 3 months after SAH. Brain cryosections were immunolabeled for ionized calcium-binding adaptor molecule-1 to detect microglia/macrophages. Neuronal nuclei and terminal deoxyuridine triphosphate-nick end labeling staining was used to visualize secondary cell death of neurons. The gene expression of various proinflammatory mediators in brain samples was analyzed by quantitative polymerase chain reaction.

RESULTS

We observed restored tissue homeostasis due to decreased microglial/macrophage accumulation and neuronal cell death 1 month after insult. However, the messenger RNA expression levels of  interleukin 6  and  tumor necrosis factor α were still elevated at 1 and 2 months post SAH, respectively. The gene expression of interleukin 1β reached its maximum on day 1, whereas at later time points, no significant differences between the groups were detected.

CONCLUSIONS

By the herein presented molecular and histological data we provide an important indication for an incomplete resolution of inflammation within the brain parenchyma after SAH. Inflammatory resolution and the return to tissue homeostasis represent an important contribution to the disease's pathology influencing the impact on brain damage and outcome after SAH. Therefore, we consider a novel complementary or even superior therapeutic approach that should be carefully rethought in the management of cerebral inflammation after SAH. An acceleration of the resolution phase at the cellular and molecular levels could be a potential aim in this context.

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.

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.

Effect of Cilostazol in Animal Models of Cerebral Ischemia and Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

BACKGROUND

Cilostazol, a phosphodiesterase III inhibitor, appears to be a promising agent for preventing cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage. Here, the authors perform a systematic review and meta-analysis to quantitatively assess the effects of cilostazol on brain structural and functional outcomes in animal models of cerebral ischemia and subarachnoid hemorrhage-induced cerebral vasospasm.

METHODS

By using the PRISMA guidelines, a search of the PubMed, Scopus, and Web of Science was conducted to identify relevant studies. Study quality of each included study for both systematic reviews were scored by using an adapted 15-item checklist from the Collaborative Approach to Meta-Analysis of Animal Data from Experimental Studies. We calculated a standardized mean difference as effect size for each comparison. For each outcome, comparisons were combined by using random-effects modeling to account for heterogeneity, with a restricted maximum likelihood estimate of between-study variance.

RESULTS

A total of 22 (median [Q1, Q3] quality score of 7 [5, 8]) and 6 (median [Q1, Q3] quality score of 6 [6, 6]) studies were identified for cerebral ischemia and subarachnoid hemorrhage-induced cerebral vasospasm, respectively. Cilostazol significantly reduced the infarct volume in cerebral ischemia models with a pooled standardized mean difference estimate of - 0.88 (95% confidence interval [CI] [- 1.07 to - 0.70], p < 0.0001). Cilostazol significantly reduced neurofunctional deficits in cerebral ischemia models with a pooled standardized mean difference estimate of - 0.66 (95% CI [- 1.06 to - 0.28], p < 0.0001). Cilostazol significantly improved the basilar artery diameter in subarachnoid hemorrhage-induced cerebral vasospasm with a pooled standardized mean difference estimate of 2.30 (95% CI [0.94 to 3.67], p = 0.001). Cilostazol also significantly improved the basilar artery cross-section area with a pooled standardized mean estimate of 1.88 (95% CI [0.33 to 3.43], p < 0.05). Overall, there was between-study heterogeneity and asymmetry in the funnel plot observed in all comparisons.

CONCLUSIONS

Published animal data support the overall efficacy of cilostazol in reducing infarct volume and neurofunctional deficits in cerebral ischemia models and cerebral vasospasm in subarachnoid hemorrhage models.

Early Brain Injury After Subarachnoid Hemorrhage: Incidence and Mechanisms

Aneurysmal subarachnoid hemorrhage is a devastating condition causing significant morbidity and mortality. While outcomes from subarachnoid hemorrhage have improved in recent years, there continues to be significant interest in identifying therapeutic targets for this disease. In particular, there has been a shift in emphasis toward secondary brain injury that develops in the first 72 hours after subarachnoid hemorrhage. This time period of interest is referred to as the early brain injury period and comprises processes including microcirculatory dysfunction, blood-brain-barrier breakdown, neuroinflammation, cerebral edema, oxidative cascades, and neuronal death. Advances in our understanding of the mechanisms defining the early brain injury period have been accompanied by improved imaging and nonimaging biomarkers for identifying early brain injury, leading to the recognition of an elevated clinical incidence of early brain injury compared with prior estimates. With the frequency, impact, and mechanisms of early brain injury better defined, there is a need to review the literature in this area to guide preclinical and clinical study.

Higher Levels of Admission N-Terminal Pro-brain Natriuretic Peptide are Associated with Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) greatly influences the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to determine whether higher levels of admission N-terminal pro-brain natriuretic peptide (NT-pro BNP) were related to neurogenic cardiac injury and predicted DCI occurrence in patients with aSAH.

METHODS

We retrospectively reviewed consecutive patients with aSAH between January 2018 and April 2021 in our department. Patients with admission NT-pro BNP were included for analysis. The associations between admission NT-pro BNP levels and admission cardiac troponin T levels and electrocardiogram characteristics, as well as the incidence of DCI, were investigated.

RESULTS

A total of 415 patients with aSAH were included, among whom DCI occurred in 53 (12.8%). The admission NT-pro BNP levels were positively correlated with the cardiac troponin T levels and were significantly higher in patients with abnormal electrocardiogram characteristics. The admission log NT-pro BNP levels were higher in patients with DCI than in those without DCI. Multivariable analysis revealed that admission log NT-pro BNP levels and modified Fisher scale were independent predictors of the incidence of DCI. Compared with the modified Fisher scale alone (area under the curve = 0.739), combining the modified Fisher scale with admission NT-pro BNP (area under the curve = 0.794) significantly improved the prediction accuracy for DCI (p < 0.001).

CONCLUSIONS

Higher admission levels of NT-pro BNP correlated with neurogenic cardiac injury and predicted the occurrence of DCI in patients with aSAH. A combination of the modified Fisher scale and admission NT-pro BNP significantly improved the prediction accuracy for DCI.

Cerebrospinal Fluid Lactate and Glucose Levels as Predictors of Symptomatic Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a complex neurovascular syndrome with profound systemic effects associated with high rates of disability and mortality. Delayed cerebral ischemia (DCI), which encompasses all neurobiological events occurring in the subacute-late stage after aSAH, has a complex pathogenesis and can occur in the absence of instrumental vasospasm. Our aim was to assess the correlation between cerebrospinal fluid (CSF) lactate and glucose levels measured on the second or third day after aSAH with clinical deterioration caused by DCI and with 3-month functional outcome.

METHODS

This prospective study included all aSAH patients admitted between January 2020 and December 2021 who underwent external ventricular drain placement and CSF lactate and glucose measurement.

RESULTS

Among 133 aSAH patients, 48 had an external ventricular drain placed and early CSF lactate and glucose assessment. Independent predictors of symptomatic DCI were World Federation of Neurosurgical Societies grade IV-V (adjusted odds ratio [aOR] 25.8, 95% confidence interval [CI] 2.9-649.2, P = 0.012), elevated CSF glucose (aOR 28.8, 95% CI 3.3-775.2, P = 0.010), and elevated CSF lactate (aOR 14.7, 95% CI 1.9-205.7, P = 0.018). The only independent predictor of 3-month functional outcome was occurrence of symptomatic DCI (aOR 0.02, 95% CI 0.0-0.2, P = 0.01).

CONCLUSIONS

Elevated CSF lactate and glucose levels in the first 3 days following aSAH were independent predictors of subsequent DCI-related neurological impairment; the presence of instrumental vasospasm was not significantly correlated with DCI after multivariate adjustment. CSF lactate and glucose monitoring may represent a point-of-care test, which could potentially improve prediction of subacute neurological worsening and guide therapeutic choices. Further research with larger prospective cohorts is warranted.

Imaging of Central Nervous System Hemorrhage

OBJECTIVE

This article aims to familiarize the reader with the various types of nontraumatic central nervous system (CNS) hemorrhage and the various neuroimaging modalities used to help diagnose and manage them.

LATEST DEVELOPMENTS

According to the 2019 Global Burden of Diseases, Injuries, and Risk Factors Study, intraparenchymal hemorrhage accounts for 28% of the global stroke burden. In the United States, hemorrhagic stroke makes up 13% of all strokes. The incidence of intraparenchymal hemorrhage increases substantially with age; thus, despite improvements in blood pressure control through various public health measures, the incidence is not decreasing as the population ages. In fact, in the most recent longitudinal study of aging, autopsy findings showed intraparenchymal hemorrhage and cerebral amyloid angiopathy in 30% to 35% of patients.

ESSENTIAL POINTS

Rapid identification of CNS hemorrhage, which includes intraparenchymal hemorrhage, intraventricular hemorrhage, and subarachnoid hemorrhage, requires either head CT or brain MRI. Once hemorrhage is identified on the screening neuroimaging study, the pattern of blood in conjunction with the history and physical examination can guide subsequent neuroimaging, laboratory, and ancillary tests as part of the etiologic assessment. After determination of the cause, the chief aims of the treatment regimen are reducing hemorrhage expansion and preventing subsequent complications such as cytotoxic cerebral edema, brain compression, and obstructive hydrocephalus. In addition, nontraumatic spinal cord hemorrhage will also be briefly discussed.

New Insights of Early Brain Injury after Subarachnoid Hemorrhage: A Focus on the Caspase Family

Spontaneous subarachnoid hemorrhage (SAH), primarily caused by ruptured intracranial aneurysms, remains a prominent clinical challenge with a high rate of mortality and morbidity worldwide. Accumulating clinical trials aiming at the prevention of cerebral vasospasm (CVS) have failed to improve the clinical outcome of patients with SAH. Therefore, a growing number of studies have shifted focus to the pathophysiological changes that occur during the periods of early brain injury (EBI). New pharmacological agents aiming to alleviate EBI have become a promising direction to improve outcomes after SAH. Caspases belong to a family of cysteine proteases with diverse functions involved in maintaining metabolism, autophagy, tissue differentiation, regeneration, and neural development. Increasing evidence shows that caspases play a critical role in brain pathology after SAH. Therefore, caspase regulation could be a potential target for SAH treatment. Herein, we provide an overview pertaining to the current knowledge on the role of caspases in EBI after SAH, and we discuss the promising therapeutic value of caspase-related agents after SAH.

The REACT study: design of a randomized phase 3 trial to assess the efficacy and safety of clazosentan for preventing deterioration due to delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

For patients presenting with an aneurysmal subarachnoid hemorrhage (aSAH), delayed cerebral ischemia (DCI) is a significant cause of morbidity and mortality. The REACT study is designed to assess the safety and efficacy of clazosentan in preventing clinical deterioration due to DCI in patients with aSAH.

METHODS

REACT is a prospective, multicenter, randomized phase 3 study that is planned to enroll 400 patients with documented aSAH from a ruptured cerebral aneurysm, randomized 1:1 to 15 mg/hour intravenous clazosentan vs. placebo, in approximately 100 sites and 15 countries. Eligible patients are required to present at hospital admission with CT evidence of significant subarachnoid blood, defined as a thick and diffuse clot that is more than 4 mm in thickness and involves 3 or more basal cisterns. The primary efficacy endpoint is the occurrence of clinical deterioration due to DCI up to 14 days post-study drug initiation. The main secondary endpoint is the occurrence of clinically relevant cerebral infarction at Day 16 post-study drug initiation. Other secondary endpoints include the modified Rankin Scale (mRS) and the Glasgow Outcome Scale-Extended (GOSE) score at Week 12 post-aSAH, dichotomized into poor and good outcome. Radiological results and clinical endpoints are centrally evaluated by independent committees, blinded to treatment allocation. Exploratory efficacy endpoints comprise the assessment of cognition status at 12 weeks and quality of life at 12 and 24 weeks post aSAH.

DISCUSSION

In the REACT study, clazosentan is evaluated on top of standard of care to determine if it reduces the risk of clinical deterioration due to DCI after aSAH. The selection of patients with thick and diffuse clots is intended to assess the benefit/risk profile of clazosentan in a population at high risk of vasospasm-related ischemic complications post-aSAH. TRIAL REGISTRATION (ADDITIONAL FILE 1): ClinicalTrials.gov (NCT03585270). EU Clinical Trial Register (EudraCT Number: 2018-000241-39).

Risk Factors for Delayed Cerebral Ischemia in Good-Grade Patients With Aneurysmal Subarachnoid Hemorrhage

Background A subset of good-grade patients with aneurysmal subarachnoid hemorrhage (aSAH) develop delayed cerebral ischemia (DCI) that may cause permanent disabilities after aSAH. However, little is known about the risk factors of DCI among this specific patient group. Methods and Results We obtained a multinational cohort of good-grade (Glasgow Coma Scale 13-15 on admission) patients with aSAH by pooling patient data from 4 clinical trials and 2 prospective cohort studies. We collected baseline data on lifestyle-related factors and the clinical characteristics of aSAHs. By calculating fully adjusted risk estimates for DCI and DCI-related poor outcome, we identified the most high-risk patient groups. The pooled study cohort included 1918 good-grade patients with aSAH (median age, 51 years; 64% women), of whom 21% and 7% experienced DCI and DCI-related poor outcome, respectively. Among men, patients with obesity and (body mass index ≥30 kg/m²) thick aSAH experienced most commonly DCI (33%) and DCI-related poor outcome (20%), whereas none of the normotensive or young (aged <50 years) men with low body mass index (body mass index <22.5 kg/m²) had DCI-related poor outcome. In women, the highest prevalence of DCI (28%) and DCI-related poor outcome (13%) was found in patients with preadmission hypertension and thick aSAH. Conversely, the lowest rates (11% and 2%, respectively) were observed in normotensive women with a thin aSAH. Conclusions Increasing age, thick aSAH, obesity, and preadmission hypertension are risk factors for DCI in good-grade patients with aSAH. These findings may help clinicians to consider which good-grade patients with aSAH should be monitored carefully in the intensive care unit.

Emergent Subarachnoid Clot Removal with Aneurysm Repair for Subarachnoid Hemorrhage Might Improves Clinical Outcome

BACKGROUND

The goal in treating patients with subarachnoid hemorrhage (SAH) is shifting to preventing early brain injury. Intracranial pressure must be controlled to manage such an injury. We retrospectively analyzed the impact of aggressive removal of cisternal subarachnoid clots with simultaneous aneurysm repair for all grades of SAH.

METHODS

Our study included 260 consecutive patients with SAH treated through aggressive subarachnoid clot removal with simultaneous aneurysm repair. Baseline patient characteristics, history, radiographic findings, and time of SAH onset to arrival in the operating room were retrospectively collected. Factors related to poor outcome (modified Rankin Scale score >2) were analyzed.

RESULTS

Multivariate analysis revealed several characteristics were significantly associated with poor outcome: advanced age (adjusted odds ratio [aOR] 1.07, 95% confidence interval [CI] 1.04-01.10); time of SAH onset to operating room per 1-hour increments (aOR 1.03, 95% CI 1.01-01.05; postoperative hematoma volume (aOR 1.04, 95% CI 1.01-01.06); and poorer World Federation of Neurosurgical Societies grade (aOR 2.18, 95% CI 1.63-02.92). According to a receiver operating characteristic analysis, the cut-off time of SAH onset to operating room was 6.0 hours (area under the curve 0.61, P = 0.01, 95% CI 0.52-0.69, sensitivity = 0.79, specificity = 0.43) as the threshold between modified Rankin Scale scores of 0-2 and 3-6.

CONCLUSIONS

Prognostic factors of SAH in patients undergoing emergent aneurysm repair with simultaneous removal of a cisternal subarachnoid clot are advanced age, poorer World Federation of Neurosurgical Societies grade, postoperative hematoma volume, and a longer time from SAH onset to operating room. The clinical outcome may improve with emergent reduction of intracranial pressure through removal of the subarachnoid clot as soon as possible.

Impact of Anemia Severity on the Outcome of an Aneurysmal Subarachnoid Hemorrhage

Objective: Previous reports indicate a negative impact of anemia on the outcome of an aneurysmal subarachnoid hemorrhage (SAH). We aimed to identify the outcome-relevant severity of post-SAH anemia. Methods: SAH cases treated at our institution between 01/2005 and 06/2016 were included (n = 640). The onset, duration, and severity (nadir hemoglobin (nHB) level) of anemia during the initial hospital stay were recorded. Study endpoints were new cerebral infarctions, a poor outcome six months post-SAH (modified Rankin scale > 3), and in-hospital mortality. To assess independent associations with the study endpoints, different multivariable regression models were performed, adjusted for relevant patient and baseline SAH characteristics as well as anemia-associated clinical events during the SAH. Results: The rates of anemia were 83.3%, 67.7%, 40.0%, 15.9%, and 4.5% for an nHB < 11 g/dL, < 10 g/dL, < 9 g/dL, < 8 g/dL, and < 7 g/dL, respectively. The higher the anemia severity, the later was the onset (post-SAH days 2, 4, 5.4, 7.6 and 8, p < 0.0001) and the shorter the duration (8 days, 6 days, 4 days, 3 days, and 2 days, p < 0.0001) of anemia. In the final multivariable analysis, only an nHB < 9 g/dL was independently associated with all study endpoints: adjusted odds ratio 1.7/3.22/2.44 for cerebral infarctions/in-hospital mortality/poor outcome. The timing (post-SAH day 3.9 vs. 6, p = 0.001) and duration (3 vs. 5 days, p = 0.041) of anemia with an nHB < 9 g/dL showed inverse associations with the risk of in-hospital mortality, but not with other study endpoints. Conclusions: Anemia is very common in SAH patients affecting four of five individuals during their hospital stay. An nHB decline to < 9 g/dL was strongly associated with all study endpoints, independent of baseline characteristics and SAH-related clinical events. Our data encourage further prospective evaluations of the value of different transfusion strategies in the functional outcomes of SAH patients.

Targeting Hemoglobin to Reduce Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) continues to be a sequela of aneurysmal subarachnoid hemorrhage (aSAH) that carries significant morbidity and mortality. Aside from nimodipine, no therapeutic agents are available to reduce the incidence of DCI. Pathophysiologic mechanisms contributing to DCI are poorly understood, but accumulating evidence over the years implicates several factors. Those have included microvessel vasoconstriction, microthrombosis, oxidative tissue damage, and cortical spreading depolarization as well as large vessel vasospasm. Common to these processes is red blood cell leakage into the cerebrospinal fluids (CSF) and subsequent lysis which releases hemoglobin, a central instigator in these events. This has led to the hypothesis that early blood removal may improve clinical outcome and reduce DCI. This paper will provide a narrative review of the evidence of hemoglobin as an instigator of DCI. It will also elaborate on available human data that discuss blood clearance and CSF drainage as a treatment of DCI. Finally, we will address a recent novel device that is currently being tested, the Neurapheresis CSF Management System™. This is an automated dual-lumen lumbar drainage system that has an option to filter CSF and return it to the patient.