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

Exclusion criteria in randomized clinical trials of subarachnoid hemorrhage

INTRODUCTION

Exclusion criteria are designed to optimize the scientific yield and safety of clinical trials. However, periodic analysis is necessary to understand the impact on trial complexity, enrollment, generalizability, and costs. We analyzed the types of exclusion criteria used among clinical trials performed in subarachnoid hemorrhage (SAH) patients and impact upon exclusion of patients.

METHODS

We identified trials involving SAH patients that provided a list of exclusion criteria and determined the number and proportion of those trials which used various exclusion criteria, proportion of excluded patients for each of the exclusion criteria and whether Consolidated Standards of Reporting Trials (CONSORT) was used. We also used target trial emulation approach and applied arbitrary trial exclusion criteria to a single center cohort of SAH patients to determine proportions of patients excluded for each of the reasons for exclusion.

RESULTS

A total of 109 trials involving SAH patients were identified, of which 68(62.3%) provided a list of the exclusion criteria. The median number of exclusion criteria was 6 (range 2-9). The most common exclusion criteria were pregnancy (n = 31 trials), SAH due to other causes (trauma, fusiform or mycotic aneurysm, n = 26 trials) and significant liver disease/hepatic insufficiency (n = 19 trials). CONSORT was used in 16(23.5%) trials and 18 (16.5%) trials provided the proportion of patients excluded according to each of the exclusion criteria. In a single center cohort, the highest proportion of patients were excluded because no aneurysm was identified on imaging (23%) followed by withdrawal of care (9.6%) and need for dual anti-platelet treatment (8.6%). The in-hospital mortality was higher in patients who were excluded as compared with those who were included in the hypothetical trial (22 [30.1%] of 73 and 0 [0%] of 31 patients).

CONCLUSIONS

Our analysis on exclusion criteria used and proportion of patients excluded in clinical trials involving SAH patients will assist in future trial enrollment, completion, and generalizability. Standardized reporting using CONSORT in clinical trials involving SAH patients is strongly recommended.

Intrathecal nicardipine for cerebral vasospasm after non-traumatic subarachnoid hemorrhage: a meta-analysis

Cerebral vasospasm is a common and serious complication following non-traumatic subarachnoid hemorrhage (SAH), often leading to worsened outcomes, especially when associated with delayed cerebral ischemia (DCI). Intrathecal nicardipine has shown potential as a treatment for vasospasm, although further research is needed to establish its effectiveness and determine its role in managing this complication. A systematic search was conducted through MEDLINE, Embase, Cochrane Library, and Web of Science databases to identify studies comparing outcome measures for intrathecal nicardipine after SAH with a control group. The primary endpoints were vasospasm severity, DCI rate, and favorable outcome at 1-6 months, assessed by functional outcome scales. Secondary outcomes included mortality, infection rates, and the need for shunt placement. A total of six studies met the eligibility criteria, and a meta-analysis using a random-effects model was conducted to pool the data. In the data analyses of 2,569 patients, in comparison with standard therapy, nicardipine use has shown statistical significance in reducing the incidence of mild vasospasm (odds ratio [OR] = 0.40; 95% confidence interval [CI] [0.20, 0.80]; p = 0.010; 𝐼² = 0%), reducing mortality rate (OR = 0.58; 95% CI [0.42, 0.81]; p = 0.001; 𝐼² = 0%), and increasing infection rate, including ventriculitis and meningitis (OR = 2.54; 95% CI [1.05, 6.19]; p = 0.040; 𝐼² = 51%). The results of this present study indicate that intrathecal nicardipine may be an effective therapeutic option for reducing the severity of vasospasm and improving mortality rates in patients with non-traumatic SAH. However, it may increase the risk of infections. Further research with randomized controlled trials is needed to confirm these findings and evaluate this treatment's long-term benefits and risks.

Spinal Drainage and Combined Pharmacotherapy as Potential Strategies to Improve Outcomes for Patients with Poor-Grade Subarachnoid Hemorrhage Treated with Clipping or Coiling but Not Receiving Nimodipine

Background/Objectives: The outcome for aneurysmal subarachnoid hemorrhage (SAH) remains poor, particularly for patients presenting with World Federation of Neurological Surgeons (WFNS) grades IV-V. This study was designed to identify independent prognostic factors in this group of patients with poor-grade SAH. Methods: We prospectively analyzed 357 SAH patients with admission WFNS grades IV-V enrolled in nine primary stroke centers in Mie prefecture, Japan, from 2013 to 2022. This study compared clinical variables, including treatments for angiographic vasospasm and delayed cerebral ischemia (DCI), between patients with favorable (modified Rankin Scale [mRS] scores 0-2) and unfavorable (mRS scores 3-6) outcomes at 90 days post-onset. Multivariate analyses were then performed to identify independent determinants of favorable 90-day outcomes, followed by propensity score matching analyses. Results: The median age was 68 years, and 53.5% of patients had admission WFNS grade V. DCI occurred in 12.9% of patients, and 66.9% had unfavorable outcomes. Independent variables related to unfavorable outcomes were older age, admission WFNS grade V, ventricular drainage, edaravone administration, and delayed cerebral infarction, while those for favorable outcomes were spinal drainage (adjusted odds ratio [aOR] 6.118, 95% confidence interval [CI] 2.687-13.927, p < 0.001), modified Fisher grade 3 (aOR 2.929, 95% CI 1.668-5.143, p < 0.001), and triple prophylactic anti-DCI medication consisting of cilostazol, fasudil hydrochloride and eicosapentaenoic acid (aOR 1.869, 95% CI 1.065-3.279, p = 0.029). Nimodipine is not approved in Japan, and statin and cerebral vasospasm did not influence outcomes. As spinal drainage and the triple prophylactic anti-DCI medication were intervenable variables, propensity score matchings were performed, and they confirmed that both spinal drainage and the triple prophylactic anti-DCI medication were useful to achieve favorable outcomes. Conclusions: In poor-grade SAH, spinal drainage and the triple prophylactic anti-DCI medication may be effective in improving outcomes, possibly by suppressing DCI pathologies other than cerebral vasospasm.

NGR1 reduces neuronal apoptosis through regulation of ITGA11 following subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH), a prevalent cerebrovascular condition associated with a high mortality rate, frequently results in neuronal apoptosis and an unfavorable prognosis. The adjunctive use of traditional Chinese medicine (TCM) with surgical interventions exerts a therapeutic impact on SAH, potentially by facilitating apoptosis. However, the mechanism by which TCM mediates apoptosis following SAH remains unclear. In the present study, C57BL/6J mice were subjected to the modified single‑clamp puncture method to produce an in vivo model of SAH. Treatment of these mice with notoginsenoside R1 (NGR1) prevented short‑term neurological deficits, reduced the expression levels of apoptosis‑associated proteins and mitigated brain edema. In addition, an in vitro model of SAH was established by treating HT22 mouse neuronal cells with oxyhemoglobin (OxyHb). Treatment of these cells with NGR1 resulted in attenuation of the OxyHb‑induced apoptosis. Furthermore, RNA sequencing analysis was used to examine NGR1 + OxyHb and OxyHb groups. Statistically significant changes in the expression levels of apoptosis‑associated genes in OxyHb‑stimulated HT22 cells upon administration of NGR1 were observed. The present study investigated the potential mechanism by which NGR1 mitigates neuronal apoptosis, presenting a novel therapeutic approach for treating SAH through the use of a single TCM component.

Regulatory T Cell- and Natural Killer Cell-Mediated Inflammation, Cerebral Vasospasm, and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage-A Systematic Review and Meta-Analysis Approach

Aneurysmal subarachnoid hemorrhage (SAH) involves a significant influx of blood into the cerebrospinal fluid, representing a severe form of stroke. Despite advancements in aneurysm closure and neuro-intensive care, outcomes remain impaired due to cerebral vasospasm and delayed cerebral ischemia (DCI). Previous pharmacological therapies have not successfully reduced DCI while improving overall outcomes. As a result, significant efforts are underway to better understand the cellular and molecular mechanisms involved. This review focuses on the activation and effects of immune cells after SAH and their interactions with neurotoxic and vasoactive substances as well as inflammatory mediators. Particular attention is given to clinical studies highlighting the roles of natural killer (NK) cells and regulatory T cells (Treg) cells. Alongside microglia, astrocytes, and oligodendrocytes, NK cells and Treg cells are key contributors to the inflammatory cascade following SAH. Their involvement in modulating the neuro-inflammatory response, vasospasm, and DCI underscores their potential as therapeutic targets and prognostic markers in the post-SAH recovery process. We conducted a systematic review on T cell- and natural killer cell-mediated inflammation and their roles in cerebral vasospasm and delayed cerebral ischemia. We conducted a meta-analysis to evaluate outcomes and mortality in studies focused on NK cell- and T cell-mediated mechanisms.

Simulated microgravity predisposes kidney to injury through promoting intrarenal artery remodeling

Spaceflight-induced multi-organ dysfunction affects the health of astronauts and the safety of in-orbit flight. However, the effect of microgravity on the kidney and the underlying mechanisms are unknown. In the current study, we used a hindlimb unweighting (HU) animal model to simulate microgravity and employed histological analysis, ischemia-reperfusion experiments, renal ultrasonography, bioinformatics analysis, isometric force measurement, and other molecular experimental settings to evaluate the effects of microgravity on the kidneys and the underlying mechanisms involved in this transition. Relative to controls, 31-day hindlimb unweighting had no obvious effect on serum creatinine and urea nitrogen levels as well as on renal injury scores; however, animals in the HU group showed an impaired renal recovery to ischemia-reperfusion injury. Ultrasonography showed that renal resistive index was increased, which indicated an altered renal hemodynamics induced by simulated microgravity. The enhanced vasoconstriction mediated by the Rho-kinase pathway and impaired vasodilation mediated by NO-eNOS of the intrarenal artery contributed to the altered renal hemodynamics. Simulated microgravity predisposes the kidney to ischemia-reperfusion injury. The altered renal hemodynamics induced by renal arterial remodeling may account for the increased renal injury susceptibility, providing a target for early intervention in kidney dysfunction under microgravity.

Nimodipine ameliorates subarachnoid hemorrhage-induced neuroinflammation and injury by protecting mitochondrial function and regulating autophagy

Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke, and the neuroprotective effects of nimodipine following SAH have been well-documented. Sirtuin 3 (SIRT3), a mitochondrial nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, plays a significant role in mitigating oxidative stress in various neurodegenerative conditions. However, the role of SIRT3 in the neuroprotective mechanisms of nimodipine after SAH remains unclear. In this study, the in vitro cytotoxicity of neurons exposed to 2% ethanol (to stimulate oxidative stress) was assessed. An in vivo experimental SAH model was established in adult mice through internal carotid perforation. A series of in vitro and in vivo experiments were conducted to investigate the function of SIRT3 and its potential mechanisms in nimodipine-treated SAH. Nimodipine, at a concentration of 10 μM within 48 h of incubation, exerted significant neuroprotective effects, enhancing SIRT3 protein expression under oxidative stress. Functional in vitro studies revealed that elevated SIRT3 expression improved mitochondrial function and promoted neuronal autophagy. Additional studies unveiled that SIRT3 knockdown or inhibition of autophagosome formation using inhibitor 3-methyladenine suppressed nimodipine-induced autophagy. The absence of autophagy increased neuronal cytotoxicity and mitochondrial dysfunction, decreased the release of anti-inflammatory cytokines, and increased the release of proinflammatory cytokines. Furthermore, blocking autophagy exacerbated neuronal apoptosis worsened neurological outcomes, and nullified the neuroprotective effects of nimodipine in the SAH mouse model. These findings highlight a mechanism where SIRT3 mediates nimodipine's neuroprotective effects by regulating mitochondrial function and autophagy. This suggests that SIRT3 serves as a promising therapeutic target for SAH.

Hyperbaric Oxygen Mediated PI3K/Akt/mTOR Pathway in Inhibiting Delayed Cerebral Vasospasm after Subarachnoid Hemorrhage

Delayed cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) is a serious complication. This article aimed to explore the mechanism of hyperbaric oxygenation (HBO) inhibiting delayed CVS after SAH. The 60 SD rats were grouped: normal control group (NC), sham operation group (Sham), SAH Model (Model), and HBO treatment group. The SAH model was established by injecting blood twice into the cisterna magna (CM), and the neurological function of the rats were evaluated by modified Garcia scale. The plasma of the rats was collected at 1, 3, 6, and 9 days after HBO treatment. Plasma levels of PI3K/Akt/mTOR pathway-related proteins were detected by Western blot (WB). TUNEL method was used to observe the apoptosis rate of basilar artery (BA) endothelial cells (ECs). Hematoxylin-eosin staining (HE) staining was used to observe the inner diameter and the thickness of vessel wall of rat cerebral arteries. The relationship between mTOR and middle cerebral artery spasm was analyzed. As against the Model, the neurological function was visibly increased, the expressions of Bcl-2, PI3K, mTOR, and p-Akt/Akt protein in plasma were visibly increased, the expression of Bax protein was visibly decreased, and the degree of CVS was visibly reduced in the HBO group (all P < 0.05). The level of mTOR is negatively correlated with the degree of CVS after SAH, and HBO can inhibit the occurrence of delayed CVS.

Symptomatic cerebral vasospasm after posterior fossa surgery in pediatric patients: single-center study and systematic literature review

PURPOSE

The most common cause of cerebral vasospasm is subarachnoid hemorrhage, less frequently it occurs after trauma, infection, and tumor resection. Vasospasm in children is rare and has not been systematically investigated in posterior fossa surgery.

METHODS

The authors undertook a single-center retrospective study of all the pediatric patients who underwent surgery on the posterior fossa and presented with postoperative symptomatic vasospasm in the period from January 2018 to February 2024. Subsequently, a systematic literature review in accordance with the PRISMA guidelines was performed in the PubMed and Scopus databases to identify the published papers on symptomatic vasospasm after posterior fossa surgery in children.

RESULTS

Of the 178 patients who underwent surgery on the posterior fossa, only one patient was diagnosed with symptomatic diffuse vasospasm on postoperative day 21. The systematic literature review provided further 9 children. The underlying pathology comprised 8 intra-axial lesions with 4 medulloblastomas, 1 schwannoma in the medulla oblongata, 1 pilocytic astrocytoma, 1 primitive neuroectodermal tumor, and 1 arteriovenous malformation. The extra-axial lesions were 1 hypoglossal schwannoma and 1 oculomotor nerve schwannoma.

CONCLUSION

Iatrogenic symptomatic vasospasm after posterior fossa surgery in children is a rare complication with an outcome ranging from complete recovery to the death of the patient. It is important for all staff involved in the care of patients undergoing surgery on the posterior fossa to be aware of this rare postoperative complication. The small number of patients affected does not allow a substantiated conclusion to be drawn about predictive risk factors.

The role of metal ions in stroke: Current evidence and future perspectives

Metal ions play a pivotal role in maintaining optimal brain function within the human body. Nevertheless, the accumulation of these ions can result in irregularities that lead to brain damage and dysfunction. Disruptions of metal ion homeostasis can result in various pathologies, including inflammation, redox dysregulation, and blood-brain barrier disruption. While research on metal ions has chiefly focused on neurodegenerative diseases, little attention has been given to their involvement in the onset and progression of stroke. Recent studies have identified cuproptosis and confirmed ferroptosis as significant factors in stroke pathology, underscoring the importance of metal ions in stroke pathology, including abnormal ion transport, neurotoxicity, blood-brain barrier damage, and cell death. Additionally, it provides an overview of contemporary metal ion chelators and detection techniques, which may offer novel approaches to stroke treatment.

Neurobehavioral Impairments Predict Specific Cerebral Damage in Rat Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a severe form of stroke that can cause unpredictable and diffuse cerebral damage, which is difficult to detect until it becomes irreversible. Therefore, there is a need for a reliable method to identify dysfunctional regions and initiate treatment before permanent damage occurs. Neurobehavioral assessments have been suggested as a possible tool to detect and approximately localize dysfunctional cerebral regions. In this study, we hypothesized that a neurobehavioral assessment battery could be a sensitive and specific method for detecting damage in discrete cerebral regions following SAH. To test this hypothesis, a behavioral battery was employed at multiple time points after SAH induced via an endovascular perforation, and brain damage was confirmed via postmortem histopathological analysis. Our results demonstrate that impairment of sensorimotor function accurately predict damage in the cerebral cortex (AUC 0.905; sensitivity 81.8%; specificity 90.9%) and striatum (AUC 0.913; sensitivity 90.1%; specificity 100%), while impaired novel object recognition is a more accurate indicator of damage to the hippocampus (AUC 0.902; sensitivity 74.1%; specificity 83.3%) than impaired reference memory (AUC 0.746; sensitivity 72.2%; specificity 58.0%). Tests for anxiety-like and depression-like behaviors predict damage to the amygdala (AUC 0.900; sensitivity 77.0%; specificity 81.7%) and thalamus (AUC 0.963; sensitivity 86.3%; specificity 87.8%), respectively. This study suggests that recurring behavioral testing can accurately predict damage in specific brain regions, which could be developed into a clinical battery for early detection of SAH damage in humans, potentially improving early treatment and outcomes.

Transcriptomics and metabolomics reveal hypothalamic metabolic characteristics and key genes after subarachnoid hemorrhage in rats

Subarachnoid hemorrhage (SAH) is a serious hemorrhagic event with high mortality and morbidity. Multiple injurious events produced by SAH can lead to a series of pathophysiologic processes in the hypothalamus that can severely impact patients' life. These pathophysiologic processes usually result in physiologic derangements and dysfunction of the brain and multiple organs. This dysfunction involved multiple dimensions of the genome and metabolome. In our study, we induced the SAH model in rats to obtain hypothalamic tissue and serum. The samples were subsequently analyzed by transcriptomics and metabolomics. Next, the functional enrichment analysis of the differentially expressed genes and metabolites were performed by GO and KEGG pathway analysis. Through transcriptomic analysis of hypothalamus samples, 263 up-regulated differential genes, and 207 down-regulated differential genes were identified in SAH groups compared to Sham groups. In the KEGG pathway analysis, a large number of differential genes were found to be enriched in IL-17 signaling pathway, PI3K-Akt signaling pathway, and bile secretion. Liquid chromatography-mass spectrometry metabolomics technology was conducted on the serum of SAH rats and identified 11 up-regulated and 26 down-regulated metabolites in positive ion model, and 1 up-regulated and 10 down-regulated metabolites in negative ion model. KEGG pathways analysis showed that differentially expressed metabolites were mainly enriched in pathways of bile secretion and primary bile acid biosynthesis. We systematically depicted the neuro- and metabolism-related biomolecular changes occurring in the hypothalamus after SAH by performing transcriptomics and metabolomics studies. These biomolecular changes may provide new insights into hypothalamus-induced metabolic changes and gene expression after SAH.

Predicting who has delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage using machine learning approach: a multicenter, retrospective cohort study

BACKGROUND

Early prediction of delayed cerebral ischemia (DCI) is critical to improving the prognosis of aneurysmal subarachnoid hemorrhage (aSAH). Machine learning (ML) algorithms can learn from intricate information unbiasedly and facilitate the early identification of clinical outcomes. This study aimed to construct and compare the ability of different ML models to predict DCI after aSAH. Then, we identified and analyzed the essential risk of DCI occurrence by preoperative clinical scores and postoperative laboratory test results.

METHODS

This was a multicenter, retrospective cohort study. A total of 1039 post-operation patients with aSAH were finally included from three hospitals in China. The training group contained 919 patients, and the test group comprised 120 patients. We used five popular machine-learning algorithms to construct the models. The area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, precision, and f1 score were used to evaluate and compare the five models. Finally, we performed a Shapley Additive exPlanations analysis for the model with the best performance and significance analysis for each feature.

RESULTS

A total of 239 patients with aSAH (23.003%) developed DCI after the operation. Our results showed that in the test cohort, Random Forest (RF) had an AUC of 0.79, which was better than other models. The five most important features for predicting DCI in the RF model were the admitted modified Rankin Scale, D-Dimer, intracranial parenchymal hematoma, neutrophil/lymphocyte ratio, and Fisher score. Interestingly, clamping or embolization for the aneurysm treatment was the fourth button-down risk factor in the ML model.

CONCLUSIONS

In this multicenter study, we compared five ML methods, among which RF performed the best in DCI prediction. In addition, the essential risks were identified to help clinicians monitor the patients at high risk for DCI more precisely and facilitate timely intervention.

Association between serum creatinine and 30 days all-cause mortality in critically ill patients with non-traumatic subarachnoid hemorrhage: analysis of the MIMIC-IV database

Background

Serum creatinine is a prognostic marker for various conditions, but its significance of spontaneous subarachnoid hemorrhage is still poorly understood. This study aims to elucidate the correlation between admission serum creatinine (sCr) levels and all-cause mortality within 30 days among individuals affected by non-traumatic subarachnoid hemorrhage (SAH).

Methods

This cohort study included 672 non-traumatic SAH adults. It utilized data from the MIMIC-IV database from 2008 to 2019. The patients' first-time serum creatinine was recorded. Subsequently, an examination of the 30-day all-cause mortality was conducted. Employing a multiple logistic regression model, a nomogram was constructed, while the association between sCr and 30-day all-cause mortality was evaluated using Kaplan-Meier survival curves. The calibration curve was employed to assess the model's performance, while subgroup analysis was employed to examine the impact of additional complications and medication therapy on outcomes.

Results

A total of 672 patients diagnosed with non-traumatic subarachnoid hemorrhage were included in the study. The mortality rate within this timeframe was found to be 24.7%. Multiple logistic regression analysis revealed that sCr served as an independent prognostic indicator for all-cause mortality within 30 days of admission for SAH patients [OR: 2(1.18-3.41); p = 0.01]. A comprehensive model was constructed, incorporating age, sCr, white blood cell count (WBC), glucose, anion gap, and partial thromboplastin time (PTT), resulting in a prediction model with an AUC value of 0.806 (95% CI: 0.768, 0.843), while the AUC for the test set is 0.821 (95% CI: 0.777-0.865).

Conclusion

Creatinine emerges as a significant biomarker, closely associated with heightened in-hospital mortality in individuals suffering from SAH.

Immediate angiographic control after intra-arterial nimodipine administration underestimates the vasodilatory effect

Intra-arterial nimodipine administration is a widely used rescue therapy for cerebral vasospasm. Although it is known that its effect sets in with delay, there is little evidence in current literature. Our aim was to prove that the maximal vasodilatory effect is underestimated in direct angiographic controls. We reviewed all cases of intra-arterial nimodipine treatment for subarachnoid hemorrhage-related cerebral vasospasm between January 2021 and December 2022. Inclusion criteria were availability of digital subtraction angiography runs before and after nimodipine administration and a delayed run for the most affected vessel at the end of the procedure to decide on further escalation of therapy. We evaluated nimodipine dose, timing of administration and vessel diameters. Delayed runs were performed in 32 cases (19 patients) with a mean delay of 37.6 (± 16.6) min after nimodipine administration and a mean total nimodipine dose of 4.7 (± 1.2) mg. Vessel dilation was more pronounced in delayed vs. immediate controls, with greater changes in spastic vessel segments (n = 31: 113.5 (± 78.5%) vs. 32.2% (± 27.9%), p < 0.0001) vs. non-spastic vessel segments (n = 32: 23.1% (± 13.5%) vs. 13.3% (± 10.7%), p < 0.0001). In conclusion intra-arterially administered nimodipine seems to exert a delayed vasodilatory effect, which should be considered before escalation of therapy.

Cerebral Infarction Due to Post-traumatic Cerebral Vasospasm in a 12-Year-Old Female

Cerebral infarction due to post-traumatic cerebral vasospasm is rare. Although some modalities are recommended to detect post-traumatic cerebral vasospasm, its diagnosis remains controversial and challenging. Therefore, in this report, we will use a case report to highlight challenges and to delineate the characteristics of post-traumatic cerebral vasospasm in pediatric patients, including the diagnostic and treatment options. A 12-year-old female was admitted to our hospital following a motor vehicle collision. Her consciousness was severely impaired. Initial computed tomography (CT) revealed an acute subdural hematoma along the tentorium, and a focal subarachnoid hemorrhage was observed in the Sylvian fissure. The patient underwent the insertion of an intracranial pressure sensor and received therapy for increased intracranial pressure (ICP) control under sedation. On the second day, CT angiography (CTA) revealed no signs of arterial abnormality. A patient who is comatose or under sedation has masked neurological symptoms. Thus, new neurological events could only be detected via an intracranial pressure sensor. Her ICP increased on the seventh day, and a CT scan showed a new cerebral infarction in the right middle cerebral artery (MCA) region. We performed decompressive craniectomy to reduce ICP. Postoperative CTA confirmed severe vasospasm in the right MCA. The severe cerebral vasospasm induced the cerebral infarction. Our review suggests that physicians in trauma departments should frequently perform vascular evaluations by CTA, magnetic resonance angiography (MRA), transcranial Doppler ultrasound, or digital subtraction angiography (DSA), especially within two weeks from onset, to detect post-traumatic cerebral vasospasm.

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.

A systematic-search-and-review of registered pharmacological therapies investigated to improve neuro-recovery after a stroke

Background

Stroke burden is largely due to long-term impairments requiring prolonged care with loss of productivity. We aimed to identify and assess studies of different registered pharmacological therapies as treatments to improve post-stroke impairments and/or disabilities.

Methods

We performed a systematic-search-and-review of treatments that have been investigated as recovery-enhancing or recovery-promoting therapies in adult patients with stroke. The treatment must have received registration or market authorization in any country regardless of primary indication. Outcomes included in the review were neurological impairments and functional/disability assessments. "The best available studies" based on study design, study size, and/or date of publication were selected and graded for level of evidence (LOE) by consensus.

Results

Our systematic search yielded 7,801 citations, and we reviewed 665 full-text papers. Fifty-eight publications were selected as "the best studies" across 25 pharmacological classes: 31 on ischemic stroke, 21 on ischemic or hemorrhagic stroke, 4 on intracerebral hemorrhage, and 2 on subarachnoid hemorrhage (SAH). Twenty-six were systematic reviews/meta-analyses, 29 were randomized clinical trials (RCTs), and three were cohort studies. Only nimodipine for SAH had LOE A of benefit (systematic review and network meta-analysis). Many studies, some of which showed treatment effects, were assessed as LOE C-LD, mainly due to small sample sizes or poor quality. Seven interventions had LOE B-R (systematic review/meta-analysis or RCT) of treatment effects.

Conclusion

Only one commercially available treatment has LOE A for routine use in stroke. Further studies of putative neuroprotective drugs as adjunctive treatment to revascularization procedures and more confirmatory trials on recovery-promoting therapies will enhance the certainty of their benefit. The decision on their use must be guided by the clinical profile, neurological impairments, and target outcomes based on the available evidence.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=376973, PROSPERO, CRD42022376973.

Cilostazol May Improve Outcomes Even in Patients with Aneurysmal Subarachnoid Hemorrhage Aged 75 Years and Older: Multicenter Cohort Study and Propensity Score-Matched Analyses

BACKGROUND

The opportunities to treat elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) are increasing globally, but the outcome remains poor. This study seeks to investigate treatment-related factors that can modify functional outcomes in patients with aSAH aged ≥75 years.

METHODS

A total of 202 patients with aSAH aged ≥75 years prospectively enrolled in 9 primary stroke centers from 2013 to 2021 were retrospectively analyzed. Clinical variables including treatments for hydrocephalus, angiographic vasospasm, and delayed cerebral ischemia were compared between patients with good (modified Rankin Scale [mRS] score 0-2) and poor (mRS score 3-6) outcomes at 90 days from onset, followed by multivariate analyses to find independent outcome determinants. A modifiable treatment-related variable was evaluated after propensity score matching with adjustments for age, sex, pre-onset mRS score, aSAH severity, and treatment modality.

RESULTS

More than half of patients showed World Federation of Neurological Societies grades IV-V on admission. Univariate analyses showed that advanced age, worse pre-onset mRS score, more severe neurologic status on admission, higher modified Fisher grade on admission computed tomography scans, and acute and chronic hydrocephalus were associated with poor outcomes. In contrast, administration of a phosphodiesterase type III inhibitor, cilostazol, was associated with good outcomes in both univariate (P = 0.036) and multivariate analyses (adjusted odds ratio, 0.305; 95% confidence interval, 0.097-0.955; P = 0.042). Propensity score matching analyses showed that patients treated with cilostazol had better outcomes (P = 0.016) with fewer incidences of delayed cerebral infarction (P = 0.008).

CONCLUSIONS

Even in patients with aSAH aged ≥75 years, cilostazol administration may lead to better outcomes by suppressing the development of delayed cerebral infarction.

Effect of magnesium sulfate on cerebral vasospasm in the treatment of aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Introduction

The use of magnesium sulfate for treating aneurysmal subarachnoid hemorrhage (aSAH) has shown inconsistent results across studies. To assess the impact of magnesium sulfate on outcomes after aSAH, we conducted a systematic review and meta-analysis of relevant randomized controlled trials.

Methods

PubMed, Embase, and the Cochrane Library were searched for relevant literature on magnesium sulfate for aSAH from database inception to March 20, 2023. The primary outcome was cerebral vasospasm (CV), and secondary outcomes included delayed cerebral ischemia (DCI), secondary cerebral infarction, rebleeding, neurological dysfunction, and mortality.

Results

Of the 558 identified studies, 16 comprising 3,503 patients were eligible and included in the analysis. Compared with control groups (saline or standard treatment), significant differences were reported in outcomes of CV [odds ratio (OR) = 0.61, p = 0.04, 95% confidence interval (CI) (0.37-0.99)], DCI [OR = 0.57, p = 0.01, 95% CI (0.37-0.88)], secondary cerebral infarction [OR = 0.49, p = 0.01, 95% CI (0.27-0.87)] and neurological dysfunction [OR = 0.55, p = 0.04, 95% CI (0.32-0.96)] after magnesium sulfate administration, with no significant differences detected in mortality [OR = 0.92, p = 0.47, 95% CI (0.73-1.15)] and rebleeding [OR = 0.68, p = 0.55, 95% CI (0.19-2.40)] between the two groups.

Conclusion

The superiority of magnesium sulfate over standard treatments for CV, DCI, secondary cerebral infarction, and neurological dysfunction in patients with aSAH was demonstrated. Further randomized trials are warranted to validate these findings with increased sample sizes.

Pathogenic mechanisms and therapeutic implications of extracellular matrix remodelling in cerebral vasospasm

Cerebral vasospasm significantly contributes to poor prognosis and mortality in patients with aneurysmal subarachnoid hemorrhage. Current research indicates that the pathological and physiological mechanisms of cerebral vasospasm may be attributed to the exposure of blood vessels to toxic substances, such as oxyhaemoglobin and inflammation factors. These factors disrupt cerebral vascular homeostasis. Vascular homeostasis is maintained by the extracellular matrix (ECM) and related cell surface receptors, such as integrins, characterised by collagen deposition, collagen crosslinking, and elastin degradation within the vascular ECM. It involves interactions between the ECM and smooth muscle cells as well as endothelial cells. Its biological activities are particularly crucial in the context of cerebral vasospasm. Therefore, regulating ECM homeostasis may represent a novel therapeutic target for cerebral vasospasm. This review explores the potential pathogenic mechanisms of cerebral vasospasm and the impacts of ECM protein metabolism on the vascular wall during ECM remodelling. Additionally, we underscore the significance of an ECM protein imbalance, which can lead to increased ECM stiffness and activation of the YAP pathway, resulting in vascular remodelling. Lastly, we discuss future research directions.

Cervical sympathectomy to treat cerebral vasospasm: a scoping review

BACKGROUND/IMPORTANCE

Delayed cerebral ischemia (DCI) is the second-leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (aSAH), and is associated with cerebral arterial vasospasm (CAV). Current treatments for CAV are expensive, invasive, and have limited efficacy. Cervical sympathetic block (CSB) is an underappreciated, but potentially highly effective therapy for CAV.

OBJECTIVE

To provide a comprehensive review of the preclinical and human literature pertinent to CSB in the context of CAV.

EVIDENCE REVIEW

This study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. We conducted a literature search using Embase, PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Scopus and Web of Science until February 2022, to identify abstracts, conference proceedings, and full-text papers pertinent to cervical sympathectomy and CAV in animal/adult patients.

FINDINGS

We included six human and six experimental studies. Human studies were mostly prospective observational, except one retrospective and one randomized clinical trial, and used various imaging modalities to measure changes in arterial diameter after the block. Studies that used digital subtraction angiography showed an improvement in cerebral perfusion without change in vessel diameter. Transcranial Doppler studies found an approximately 15% statistically significant decrease in velocities consistent with arterial vasodilatation. Overall, the results suggest an increase in cerebral arterial diameter and neurological improvement in patients receiving a CSB. Animal studies demonstrate that sympathetic system ablation vasodilates cerebral vasculature and decreases the incidence of symptomatic vasospasm.

CONCLUSIONS

This scoping review suggests that CSB may be a viable option for treatment and prevention of CAV/DCI in patients with aSAH, although the included studies were heterogeneous, mostly observational, and with a small sample size. Further research is needed to standardize the technique and prove its effectiveness to treat patients suffering of CAV/DCI after aSAH.

Serum concentration-guided intravenous magnesium sulfate administration for neuroprotection in patients with aneurysmal subarachnoid hemorrhage: a retrospective evaluation of a 12-year single-center experience

Delayed cerebral infarction (DCI) is a major cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH). The benefits of magnesium sulfate as an alternative treatment are controversial, and most previous studies examined its benefits only as adjunctive treatment to traditional nimodipine. We retrospectively analyzed aSAH patients records with magnesium sulfate between 2010 and 2021. We aimed for a serum magnesium concentration of 2-2.5 mmol/l between post-hemorrhage days 3 and 12. The patients were separated in three groups based on average serum magnesium concentration (magnesium >2 mmol/l, reduced magnesium 1.1-1.9 mmol/l, and no magnesium). Additionally, we assessed delayed cerebral infarction (DCI) and clinical outcome at follow-up, using the modified Rankin Scale (mRS), categorized in favorable (0-3) and unfavorable outcome (4-5). In this analysis, 548 patients were included. Hereof, radiological evidence of DCI could be found in 23.0% (n = 126) of patients. DCI rates were lower if patients' average serum magnesium was higher than 2 mmol/l (magnesium 18.8%, n = 85; reduced magnesium 38.3%, n = 23; no magnesium 51.4%, n = 18; p < 0.001). Also, at the last follow-up, patients in the group with a higher serum magnesium concentration had better outcome (favorable outcome: magnesium 64.7%, n = 293; reduced magnesium 50.0%, n = 30; no magnesium 34.3%, n = 12; p < 0.001). This 12-year study reveals the value of serum concentration-guided magnesium administration in aSAH patients. Our findings demonstrate the safety and efficacy when titrated to a serum concentration of 2-2.5 mmol/l. We observed higher rates of delayed cerebral infarction and unfavorable outcomes in patients with serum concentrations below 2 mmol/l.

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.

Impact of Early Out-of-Bed Mobilization on Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Cohort Study

BACKGROUND

Effects of early mobilization are not well documented in patients with aneurysmal subarachnoid hemorrhage (aSAH). Only a few studies have investigated it through progressive mobilization protocols and suggested that it is safe and feasible. This study aimed to determine the impact of early out-of-bed mobilization (EOM) on 3-month functional outcome and cerebral vasospasm (CVS) occurrence in patients with aSAH.

METHODS

A retrospective review of consecutive patients admitted to the intensive care unit with a diagnosis of aSAH was performed. EOM was defined as out-of-bed (OOB) mobilization performed before or on day 4 after aSAH onset. The primary outcome was 3-month functional independence (i.e., a modified Rankin Scale below 3) and the occurrence of CVS.

RESULTS

A total of 179 patients with aSAH met the inclusion criteria. Thirty-one patients constituted the EOM group, and 148 patients were in the delayed out-of-bed mobilization group. Functional independence was more frequent in the EOM group than in the delayed out-of-bed mobilization group (n = 26 [84%] vs. n = 83 [56%], P = 0.004). In a multivariable analysis, EOM was an independent predictor of functional independence (adjusted odds ratio = 3.11; 95% confidence interval, 1.11-10.36; P < 0.05). The delay between bleeding and first OOB mobilization was also identified as an independent risk factor for the occurrence of CVS (adjusted odds ratio = 1.12; 95% confidence interval = 1.06-1.18, P < 0.001).

CONCLUSIONS

EOM was independently associated with favorable functional outcome after aSAH. The delay between bleeding and OOB mobilization was an independent risk factor for reduced functional independence and CVS occurrence. Prospective randomized trials are necessary to confirm these results and improve clinical practice.

Neurobehavioral impairments predict specific cerebral damage in rat model of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a severe form of stroke that can cause unpredictable and diffuse cerebral damage, which is difficult to detect until it becomes irreversible. Therefore, there is a need for a reliable method to identify dysfunctional regions and initiate treatment before permanent damage occurs. Neurobehavioral assessments have been suggested as a possible tool to detect and approximately localize dysfunctional cerebral regions. In this study, we hypothesized that a neurobehavioral assessment battery could be a sensitive and specific early warning for damage in discrete cerebral regions following SAH. To test this hypothesis, a behavioral battery was employed at multiple time points after SAH induced via an endovascular perforation, and brain damage was confirmed via postmortem histopathological analysis. Our results demonstrate that impairment of sensorimotor function accurately predict damage in the cerebral cortex (AUC: 0.905; sensitivity: 81.8%; specificity: 90.9%) and striatum (AUC: 0.913; sensitivity: 90.1%; specificity: 100%), while impaired novel object recognition is a more accurate indicator of damage to the hippocampus (AUC: 0.902; sensitivity: 74.1%; specificity: 83.3%) than impaired reference memory (AUC: 0.746; sensitivity: 72.2%; specificity: 58.0%). Tests for anxiety-like and depression-like behaviors predict damage to the amygdala (AUC: 0.900; sensitivity: 77.0%; specificity: 81.7%) and thalamus (AUC: 0.963; sensitivity: 86.3%; specificity: 87.8%), respectively. This study suggests that recurring behavioral testing can accurately predict damage in specific brain regions, which could be developed into a clinical battery for early detection of SAH damage in humans, potentially improving early treatment and outcomes.

Immunological Profile of Vasospasm after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) carries high mortality and disability rates, which are substantially driven by complications. Early brain injury and vasospasm can happen after SAH and are crucial events to prevent and treat to improve prognosis. In recent decades, immunological mechanisms have been implicated in SAH complications, with both innate and adaptive immunity involved in mechanisms of damage after SAH. The purpose of this review is to summarize the immunological profile of vasospasm, highlighting the potential implementation of biomarkers for its prediction and management. Overall, the kinetics of central nervous system (CNS) immune invasion and soluble factors' production critically differs between patients developing vasospasm compared to those not experiencing this complication. In particular, in people developing vasospasm, a neutrophil increase develops in the first minutes to days and pairs with a mild depletion of CD45+ lymphocytes. Cytokine production is boosted early on after SAH, and a steep increase in interleukin-6, metalloproteinase-9 and vascular endothelial growth factor (VEGF) anticipates the development of vasospasm after SAH. We also highlight the role of microglia and the potential influence of genetic polymorphism in the development of vasospasm and SAH-related complications.

Inflammatory Markers as Predictors of Shunt Dependency and Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage

The mechanisms underlying post-hemorrhagic hydrocephalus (PHH) development following subarachnoid hemorrhage (SAH) are not fully understood, which complicates informed clinical decisions regarding the duration of external ventricular drain (EVD) treatment and prevents the prediction of shunt-dependency in the individual patient. The aim of this study was to identify potential inflammatory cerebrospinal fluid (CSF) biomarkers of PHH and, thus, shunt-dependency and functional outcome in patients with SAH. This study was a prospective observational study designed to evaluate inflammatory markers in ventricular CSF. In total, 31 Patients with SAH who required an EVD between June 2019 and September 2021 at the Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark, were included. CSF samples were collected twice from each patient and analyzed for 92 inflammatory markers via proximity extension assay (PEA), and the prognostic ability of the markers was investigated. In total, 12 patients developed PHH, while 19 were weaned from their EVD. Their 6-month functional outcome was determined with the modified Rankin Scale. Of the 92 analyzed inflammatory biomarkers, 79 were identified in the samples. Seven markers (SCF, OPG, LAP TGFβ1, Flt3L, FGF19, CST5, and CSF1) were found to be predictors of shunt dependency, and four markers (TNFα, CXCL5, CCL20, and IL8) were found to be predictors of functional outcome. In this study, we identified promising inflammatory biomarkers that are able to predict (i) the functional outcome in patients with SAH and (ii) the development of PHH and, thus, the shunt dependency of the individual patients. These inflammatory markers may have the potential to be employed as predictive biomarkers of shunt dependency and functional outcome following SAH and could, as such, be applied in the clinic.