Core outcomes for subarachnoid haemorrhage

Mitophagy in acute central nervous system injuries: regulatory mechanisms and therapeutic potentials

Acute central nervous system injuries, including ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury, are a major global health challenge. Identifying optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent priorities. Mitochondria are susceptible to damage after acute central nervous system injury, and this leads to the release of toxic levels of reactive oxygen species, which induce cell death. Mitophagy, a selective form of autophagy, is crucial in eliminating redundant or damaged mitochondria during these events. Recent evidence has highlighted the significant role of mitophagy in acute central nervous system injuries. In this review, we provide a comprehensive overview of the process, classification, and related mechanisms of mitophagy. We also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate mitophagy. In the final section of this review, we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

Liberal or Restrictive Transfusion Strategy in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The effect of a liberal red-cell transfusion strategy as compared with a restrictive strategy in patients during the critical care period after an aneurysmal subarachnoid hemorrhage is unclear.

METHODS

We randomly assigned critically ill adults with acute aneurysmal subarachnoid hemorrhage and anemia to a liberal strategy (mandatory transfusion at a hemoglobin level of ≤10 g per deciliter) or a restrictive strategy (optional transfusion at a hemoglobin level of ≤8 g per deciliter). The primary outcome was an unfavorable neurologic outcome, defined as a score of 4 or higher on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability), at 12 months. Secondary outcomes included 12-month functional independence as assessed with the Functional Independence Measure (FIM; scores range from 18 to 126) and quality of life as assessed with the EuroQol five-dimension, five-level (EQ-5D-5L) utility index (scores range from -0.1 to 0.95) and a visual analogue scale (VAS; scores range from 0 to 100); on each assessment, higher scores indicate better health status or quality of life.

RESULTS

A total of 742 patients underwent randomization at 23 centers. The analysis of the primary outcome at 12 months included 725 patients (97.7%). An unfavorable neurologic outcome occurred in 122 of 364 patients (33.5%) in the liberal-strategy group and in 136 of 361 patients (37.7%) in the restrictive-strategy group (risk ratio, 0.88; 95% confidence interval [CI], 0.72 to 1.09; P = 0.22). The mean (±SD) FIM score was 82.8±54.6 in the liberal-strategy group and 79.8±54.5 in the restrictive-strategy group (mean difference, 3.01; 95% CI, -5.49 to 11.51). The mean EQ-5D-5L utility index score was 0.5±0.4 in both groups (mean difference, 0.02; 95% CI, -0.04 to 0.09). The mean VAS score was 52.1±37.5 in the liberal-strategy group and 50±37.1 in the restrictive-strategy group (mean difference, 2.08; 95% CI, -3.76 to 7.93). The incidence of adverse events was similar in the two groups.

CONCLUSIONS

In patients with aneurysmal subarachnoid hemorrhage and anemia, a liberal transfusion strategy did not result in a lower risk of an unfavorable neurologic outcome at 12 months than a restrictive strategy. (Funded by the Canadian Institutes of Health Research and others; SAHARA ClinicalTrials.gov number, NCT03309579.).

Methods of functional outcome assessment in neurocritical care trials: A systematic review and meta-analysis

BACKGROUND

Acute brain injury due to conditions such as subarachnoid haemorrhage and traumatic brain injury are associated with physical, psychological, cognitive, emotional, and social deficits. Despite reductions in morbidity and mortality, there have been few significant changes in clinical practice. It has been suggested that heterogeneity in outcome assessment in studies has contributed to this limited progress.

OBJECTIVES

The objectives of this study were to describe current methods of outcome assessment in aneurysmal subarachnoid haemorrhage and traumatic brain injury studies and to examine the relationship between methods of outcome assessment and reported outcomes.

METHODS

We performed a systematic review and meta-analysis of randomised controlled trials and cohort studies enrolling an adult aneurysmal subarachnoid haemorrhage or traumatic brain injury population and reporting at least one functional outcome measure.

RESULTS

We identified 176 studies, including 60 494 participants. The Glasgow Outcome Scale or the Glasgow Outcome Scale Extended was used in 68% (N = 120) of studies and the Modified Rankin Scale in 38% (N = 67) of studies. Outcome assessment was reported at different timepoints, using different methods of application, and often dichotomised using different ranges. Many studies did not report key details on methods of outcome assessment. Outcome assessment using the Modified Rankin Scale was associated with a higher proportion of patients reported as having a favourable outcome 0.62 (95% confidence interval [CI]: 0.58-0.67) than the Glasgow Outcome Scale 0.48 (95% CI: 0.43-0.53) or the Glasgow Outcome Scale Extended 0.42 (95% CI: 0.37-0.48, p < 0.01). In-person assessment was associated with an increased proportion of patients achieving a favourable outcome 0.55 (95% CI: 0.55-0.45) compared to telephone assessment 0.46 (95% CI: 0.40-0.52).

CONCLUSION

There is significant heterogeneity and incomplete reporting of methods of outcome assessment in critical care studies enrolling aneurysmal subarachnoid haemorrhage and traumatic brain injury patient populations. Our study identified an association between the methods of outcome assessment and reported outcomes. Our study supports initiatives to standardise outcome assessment in neurocritical care research to ensure the quality of outcome data.

REGISTRATION

The International Prospective Register of Systematic Reviews (CRD42023072206).

What to Measure in Aneurysmal Subarachnoid Haemorrhage Research-An International Delphi Survey

Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating condition with high mortality and morbidity. The outcome measures used in aSAH clinical research vary making it challenging to compare and combine different studies. Additionally, there may be a mismatch between the outcomes prioritized by patients, caregivers, and health care providers and those selected by researchers. We conducted an international, online, multiple round Delphi study to develop consensus on domains (where a domain is a health concept or aspect) prioritized by key stakeholders including those with lived experience of aSAH, health care providers, and researchers, funders, or industry professionals. One hundred seventy-five people participated in the survey, 59% of whom had lived experience of aSAH. Over three rounds, 32 domains reached the consensus threshold pre-defined as 70% of participants rating the domain as being critically important. During the fourth round, participants ranked the importance of each of these 32 domains. The top ten domains ranked highest to lowest were (1) Cognition and executive function, (2) Aneurysm obliteration, (3) Cerebral infarction, (4) Functional outcomes including ability to walk, (5) Delayed cerebral ischemia, (6) The overall quality of life as reported by the SAH survivor, (7) Changes to emotions or mood (including depression), (8) The basic activities of daily living, (9) Vasospasm, and (10) ICU complications. Our findings confirm that there is a mismatch between domains prioritized by stakeholders and outcomes used in clinical research. Our future work aims to address this mismatch through the development of a core outcome set in aSAH research.

One-year outcome and quality of life of patients with subarachnoid hemorrhage admitted to intensive care unit: a single-center retrospective pilot study

Patients admitted to intensive care unit (ICU) after non-traumatic subarachnoid hemorrhage (SAH) represent a group with distinctive characteristics and few data are available on long-term outcome in this population. We conducted a single-center retrospective study in an Italian intensive care unit. All patients with non-traumatic SAH (ICD-9-CM Diagnosis Code 430) admitted to ICU were included. Disability and quality of life were evaluated via telephone interview after 12-15 months after initial bleeding using GOSE and EuroQoL, respectively. Baseline and clinical course characteristics were analyzed to evaluate relation with poor outcome defined as GOSE ≤ 3. Final population consisted of 38 patients. Twenty-four patients (63.2%) had favorable outcome (GOSE ≥ 4). Among 29 patients (76.3%) who survived at 1 year, median EQ-5D Index was 0.743 (IQR 0.287), while median EQ-VAS was 74.79 (IQR 18.5). Median EQ-5D Index and median EQ-VAS were higher among patients with favorable outcome (EQ-5D Index p = 0.037, EQ-VAS p = 0.003). Among baseline characteristics, only HH scale showed a significant relation with disability at one year (p = 0.033). Between complications occurred during ICU-stay only early HICP was related with unfavorable outcome (p = 0.028). Higher HH scale and early HICP were related with unfavorable outcome. Among patients with unfavorable outcome, quality of life has a broad range of variability, and this result should be taken into account when reporting patient-centered outcomes.

Subarachnoid haemorrhage and intracranial aneurysms in Greenland in the period 2018-2021: incidence, outcome and familial disposition

Subarachnoid haemorrhages (SAH) caused by rupture of intracranial aneurysms (IA) are a severe condition. Earlier studies found a higher incidence of SAH in Greenlandic patients compared to Danish patients, with familial aggregation also higher in Greenland. However, updated data is lacking. To investigate the contemporary incidence, outcome, and familial disposition of SAH/IA in Greenlandic patients in 2018-2021. Greenlandic patients diagnosed with ruptured or unruptured IA (UIA) during 2018-2021 were included. Data was obtained from patient files, x-ray department, and discharge registry. Incidence rates were estimated as cases/100,000/year. Direct age-standardised incidence rates were calculated using WHO 2000-2025 as standards. Of 30 SAH patients, 20 (66.7%) were females, 10 (33.3%) males. Of 36 UIA patients, 27 (75.0%) were females, 9 (25.0%) males. For SAH, crude incidence was 13.4/100,000/year, age-standardised incidence was 10.8/100,000/year. Familial history was observed in 30.0% of SAH patients. 5 patients (16.7%) died before treatment, 28-day case-fatality rate (CFR) for all patients was 23.3%. Overall and age-standardised incidence rates were similar to previous studies but higher among females and compared to neighbouring countries. A high occurrence of familial history was reported. SAH remains a serious condition in Greenland, as evidenced by five fatalities before treatment was administered.

Analysis of selective neurocritical care admission costs following elective endovascular treatment of unruptured intracranial aneurysms

INTRODUCTION

No consensus exists on the necessity of neurocritical care unit (NCU)-level care following unruptured intracranial aneurysm (UIA) treatment. We aim to identify patients requiring NCU-level care post-treatment and determine potential cost savings utilizing a selective NCU admission protocol.

METHODS

A retrospective analysis of all UIA patients who underwent endovascular treatment at a single center from 2017-2022 was conducted. Data on demographics, preprocedural variables, radiographic features, procedural techniques, intra/postoperative events, and length of stay (LOS) were collected. Multivariable analysis was performed to identify patients requiring NCU-level care post-treatment. Cost analysis using hospital cost data (not charges/reimbursement) was performed using simulated step-down and floor protocols for patients without NCU indications following a hypothetical six-hour post-anesthesia care unit observation period.

RESULTS

Of 209 patients, 179 were discharged within 24 h and 30 had prolonged LOS. In our analysis, intra- and postoperative events independently predicted prolonged LOS. In our subanalysis, 47 patients demonstrated NCU needs: 24 with intraoperative indications, 18 with postoperative indications, and five with both. Of the 23 with postoperative indications, 20 were identified within six hours, while three were identified within six to 24 h. The median variable cost per patient for the current NCU protocol was $31,505 (IQR, $26,331-$37,053) vs. stepdown protocol $29,514 (IQR, $24,746-$35,011;p = 0.061) vs. floor protocol $26,768 (IQR, $22,214-$34,107;p < 0.001). Total variable costs were $6,211,497 for the current NCU protocol vs. $5,921,912 for the step-down protocol (4.89% savings) and $5,509,052 for the floor protocol (12.75% savings).

CONCLUSION

Most patients requiring NCU-level care following UIA treatment were identified within a six-hour postoperative window. Thus, selective NCU admission for this cohort following a six-hour observation period may be a logical avenue for cost reduction. Our analysis demonstrated 5% and 13% savings for uncomplicated patients using step-down and floor admission protocols, respectively.

Inflammasome Proteins Are Reliable Biomarkers of the Inflammatory Response in Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is caused by abnormal blood vessel dilation and subsequent rupture, resulting in blood pooling in the subarachnoid space. This neurological insult results in the activation of the inflammasome, a multiprotein complex that processes pro-inflammatory interleukin (IL)-1 cytokines leading to morbidity and mortality. Moreover, increases in inflammasome proteins are associated with clinical deterioration in many neurological diseases. Limited studies have investigated inflammasome protein expression following aSAH. Reliable markers of the inflammatory response associated with aSAH may allow for earlier detection of patients at risk for complications and aid in the identification of novel pharmacologic targets. Here, we investigated whether inflammasome signaling proteins may serve as potential biomarkers of the inflammatory response in aSAH. Serum and cerebrospinal fluid (CSF) from fifteen aSAH subjects and healthy age-matched controls and hydrocephalus (CSF) no-aneurysm controls were evaluated for levels of inflammasome signaling proteins and downstream pro-inflammatory cytokines. Protein measurements were carried out using Simple Plex and Single-Molecule Array (Simoa) technology. The area under the curve (AUC) was calculated using receiver operating characteristics (ROCs) to obtain information on biomarker reliability, specificity, sensitivity, cut-off points, and likelihood ratio. In addition, a Spearman r correlation matrix was performed to determine the correlation between inflammasome protein levels and clinical outcome measures. aSAH subjects demonstrated elevated caspase-1, apoptosis-associated speck-like protein with a caspase recruiting domain (ASC), IL-18 and IL-1β levels in serum, and CSF when compared to controls. Each of these proteins was found to be a promising biomarker of inflammation in aSAH in the CSF. In addition, ASC, caspase-1, and IL-1β were found to be promising biomarkers of inflammation in aSAH in serum. Furthermore, we found that elevated levels of inflammasome proteins in serum are useful to predict worse functional outcomes following aSAH. Thus, the determination of inflammasome protein levels in CSF and serum in aSAH may be utilized as reliable biomarkers of inflammation in aSAH and used clinically to monitor patient outcomes.

Dynamically Normalized Pupillometry for Detecting Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES

Delayed cerebral ischemia (DCI) is a major driver of morbidity after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative pupillometry has been shown to be of prognostic value after acute neurological injury. However, the evidence for the use of pupillometric features for the detection of DCI has been conflicting. The aim of this study was to investigate the prognostic value of frequent pupillometric monitoring for DCI detection.

DESIGN

Observational cohort study from a prospective aSAH registry.

SETTING

Tertiary referral center.

PATIENTS

Adult patients with confirmed aSAH admitted to the ICU between March 2019 and December 2023.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred fourteen patients were included, of which 31 (27.2%) suffered from DCI. All patients underwent frequent pupillometry (every 3 hr). We determined the absolute value of the neurological pupil index (NPi) and constriction velocity (CV), and their value normalized to the maximal recorded value between the admission and the pupillometry measure to account for personalized baselines. The association between pupillometry values and the occurrence of DCI within 6-24 hours was investigated. Normalized CV had the best discriminative performance to identify DCI within 8 hours, with an area under the receiver operating characteristic curve of 0.82 (95% CI, 0.69-0.91). NPi, as well as non-normalized metrics, were not significantly associated with DCI.

CONCLUSIONS

Normalized CV has a clinically and statistically significant association with the occurrence of DCI after aSAH. Frequent quantitative pupillometry could improve the multimodal monitoring of patients after aSAH with the goal of improving the identification of patients likely to benefit from therapeutic interventions.

Targeting brain-peripheral immune responses for secondary brain injury after ischemic and hemorrhagic stroke

The notion that the central nervous system is an immunologically immune-exempt organ has changed over the past two decades, with increasing evidence of strong links and interactions between the central nervous system and the peripheral immune system, both in the healthy state and after ischemic and hemorrhagic stroke. Although primary injury after stroke is certainly important, the limited therapeutic efficacy, poor neurological prognosis and high mortality have led researchers to realize that secondary injury and damage may also play important roles in influencing long-term neurological prognosis and mortality and that the neuroinflammatory process in secondary injury is one of the most important influences on disease progression. Here, we summarize the interactions of the central nervous system with the peripheral immune system after ischemic and hemorrhagic stroke, in particular, how the central nervous system activates and recruits peripheral immune components, and we review recent advances in corresponding therapeutic approaches and clinical studies, emphasizing the importance of the role of the peripheral immune system in ischemic and hemorrhagic stroke.

Mitochondrial dysfunction and quality control lie at the heart of subarachnoid hemorrhage

The dramatic increase in intracranial pressure after subarachnoid hemorrhage leads to a decrease in cerebral perfusion pressure and a reduction in cerebral blood flow. Mitochondria are directly affected by direct factors such as ischemia, hypoxia, excitotoxicity, and toxicity of free hemoglobin and its degradation products, which trigger mitochondrial dysfunction. Dysfunctional mitochondria release large amounts of reactive oxygen species, inflammatory mediators, and apoptotic proteins that activate apoptotic pathways, further damaging cells. In response to this array of damage, cells have adopted multiple mitochondrial quality control mechanisms through evolution, including mitochondrial protein quality control, mitochondrial dynamics, mitophagy, mitochondrial biogenesis, and intercellular mitochondrial transfer, to maintain mitochondrial homeostasis under pathological conditions. Specific interventions targeting mitochondrial quality control mechanisms have emerged as promising therapeutic strategies for subarachnoid hemorrhage. This review provides an overview of recent research advances in mitochondrial pathophysiological processes after subarachnoid hemorrhage, particularly mitochondrial quality control mechanisms. It also presents potential therapeutic strategies to target mitochondrial quality control in subarachnoid hemorrhage.

Monitoring of Perioperative Microcirculation Dysfunction by Near-Infrared Spectroscopy for Neurological Deterioration and Prognosis of Aneurysmal Subarachnoid Hemorrhage: An Observational, Longitudinal Cohort Study

INTRODUCTION

No evidence has established a direct causal relationship between early microcirculation disturbance after aneurysmal subarachnoid hemorrhage (aSAH) and neurological function prognosis, which is the key pathophysiological mechanism of early brain injury (EBI) in patients with aSAH.

METHODS

A total of 252 patients with aSAH were enrolled in the Neurosurgical Intensive Care Unit of Southwest Hospital between January 2020 and December 2022 and divided into the no neurological deterioration, early neurological deterioration, and delayed neurological deterioration groups. Indicators of microcirculation disorders in EBI included regional cerebral oxygen saturation (rSO2) measured by near-infrared spectroscopy (NIRS), brain oxygen monitoring, and other clinical parameters for evaluating neurological function and determining the prognosis of patients with aSAH.

RESULTS

Our data suggest that the rSO2 is generally lower in patients who develop neurological deterioration than in those who do not and that there is at least one time point in the population of patients who develop neurological deterioration where left and right cerebral hemisphere differences can be significantly monitored by NIRS. An unordered multiple-classification logistic regression model was constructed, and the results revealed that multiple factors were effective predictors of early neurological deterioration: reoperation, history of brain surgery, World Federation of Neurosurgical Societies (WFNS) grade 4-5, Fisher grade 3-4, SAFIRE grade 3-5, abnormal serum sodium and potassium levels, and reduced rSO2 during the perioperative period. However, for delayed neurological deterioration in patients with aSAH, only a history of brain surgery and perioperative RBC count were predictive indicators.

CONCLUSIONS

The rSO2 concentration in patients with neurological deterioration is generally lower than that in patients without neurological deterioration, and at least one time point in the population with neurological deterioration can be significantly monitored via NIRS. However, further studies are needed to determine the role of microcirculation and other predictive factors in the neurocritical management of EBI after aSAH, as these factors can reduce the incidence of adverse outcomes and mortality during hospitalization.

Correlation of Inflammatory Parameters with the Development of Cerebral Vasospasm, Takotsubo Cardiomyopathy, and Functional Outcome after Spontaneous Subarachnoid Hemorrhage

Background: The present work aimed to determine whether a relationship exists between inflammatory parameters and the development of vasospasm (VS) and Takotsubo cardiomyopathy (TTC), as well as clinical outcome, in patients suffering from spontaneous subarachnoid hemorrhage (SAH). Methods: In this study, the authors processed the prospectively collected laboratory and clinical data of spontaneous SAH patients admitted to the neurointensive care unit between March 2015 and October 2023. The highest values of neutrophils (NEUpeak), monocytes (MONOpeak), neutrophil-to-lymphocyte ratio (NLRpeak), and CRP (CRPpeak) during the initial 7 days were correlated with the occurrence of VS and TTC, and with the outcome measures at day 30 after onset. Results: Data were collected from 175 SAH patients. Based on ROC analysis, for the development of VS, MONOpeak was the most accurate indicator (AUC: 0.619, optimal cut-off: 1.45 G/L). TTC with severe left ventricular dysfunction (ejection fraction < 40%) was indicated most sensitively by NEUpeak (ROC: 0.763, optimal cut-off: 12.34 G/L). Both for GOS and Barthel Index at day 30, CRPpeak was the best predictor for the outcome (GOS: ROC: 0.846, optimal cut-off: 78.33 mg/L and Barthel Index: ROC: 0.819, optimal cut-off: 78.33 mg/L). Conclusions: Laboratory parameters referring to inflammation during the initial 7 days after SAH correlate with the development of VS and TTC, and thus may predict functional outcome.

Hydrogen exerts neuroprotective effects after subarachnoid hemorrhage by attenuating neuronal ferroptosis and inhibiting neuroinflammation

OBJECTIVE

Spontaneous subarachnoid hemorrhage (SAH), the third most common stroke subtype, is associated with high mortality and disability rates. Therefore, finding effective therapies to improve neurological function after SAH is critical. The objective of this study was to investigate the potential neuroprotective effects of hydrogen in the context of SAH, specifically, by examining its role in attenuating neuronal ferroptosis and inhibiting neuroinflammation, which are exacerbated by excess iron ions after SAH.

METHODS

Mice were exposed to chambers containing 3% hydrogen, and cells were cultured in incubators containing 60% hydrogen. Neurological function in mice was assessed using behavioral scores. Protein changes were detected using western blotting. Inflammatory factors were detected using enzyme linked immunosorbent assay. Probes, electron microscopy, and related kits were employed to detect oxidative stress and ferroptosis.

RESULTS

Hydrogen improved the motor function, sensory function, and cognitive ability of mice after SAH. Additionally, hydrogen facilitated Nuclear factor erythroid 2 -related factor 2 activation, upregulated Glutathione peroxidase 4, and inhibited Toll-like receptor 4, resulting in downregulation of inflammatory responses, attenuation of oxidative stress after SAH, and inhibition of neuronal ferroptosis.

CONCLUSION

Hydrogen exerts neuroprotective effects by inhibiting neuronal ferroptosis and attenuating neuroinflammation after SAH.

Predictor role of heart rate variability in subarachnoid hemorrhage: A systematic review

Background- Subarachnoid hemorrhage (SAH) is one of the most devastating diseases with a high rate of morbidity and mortality. The heart rate variability (HRV) is a non-invasive method of monitoring various components of the autonomic nervous system activity that can be utilized to delineate autonomic dysfunctions associated with various physiological and pathological conditions. The reliability of HRV as a predictor of clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH) is not yet well investigated in literature. Methods- A systematic review and in depth analysis of 10 articles on early HRV changes in SAH patients was performed. Results- This systematic review demonstrates a correlation between early changes in HRV indices (time and frequency domain) and the development of neuro-cardiogenic complications and poor neurologic outcome in patients with SAH. Conclusions- A correlation between absolute values or changes of the LF/HF ratio and neurologic and cardiovascular complications was found in multiple studies. Because of significant limitations of included studies, a large prospective study with proper handling of confounders is needed to generate high-quality recommendations regarding HRV as a predictor of post SAH complications and poor neurologic outcome.

Astrocyte-derived hepcidin aggravates neuronal iron accumulation after subarachnoid hemorrhage by decreasing neuronal ferroportin1

Iron accumulation is one of the most essential pathological events after subarachnoid hemorrhage (SAH). Ferroportin1 (FPN1) is the only transmembrane protein responsible for exporting iron. Hepcidin, as the major regulator of FPN1, is responsible for its degradation. Our study investigated how the interaction between FPN1 and hepcidin contributes to iron accumulation after SAH. We found that iron accumulation aggravated after SAH, along with decreased FPN1 in neurons and increased hepcidin in astrocytes. After knocking down hepcidin in astrocytes, the neuronal FPN1 significantly elevated, thus attenuating iron accumulation. After SAH, p-Smad1/5 and Smad4 tended to translocate into the nucleus. Moreover, Smad4 combined more fragments of the promoter region of Hamp after OxyHb stimulation. By knocking down Smad1/5 or Smad4 in astrocytes, FPN1 level restored and iron overload attenuated, leading to alleviated neuronal cell death and improved neurological function. However, the protective role disappeared after recombinant hepcidin administration. Therefore, our study suggests that owing to the nuclear translocation of transcription factors p-Smad1/5 and Smad4, astrocyte-derived hepcidin increased significantly after SAH, leading to a decreased level of neuronal FPN1, aggravation of iron accumulation, and worse neurological outcome.

Menaquinone-4 attenuates ferroptosis by upregulating DHODH through activation of SIRT1 after subarachnoid hemorrhage

BACKGROUND

Menaquinone-4(MK-4), the isoform of vitamin K2 in the brain, exerts neuroprotective effects against a variety of central nervous system disorders. This study aimed to demonstrate the anti-ferroptosis effects of MK-4 in neurons after SAH.

METHODS

A subarachnoid hemorrhage (SAH) model was prepared by endovascular perforation in mice. In vitro hemoglobin stimulation of primary cortical neurons mimicked SAH. MK-4, Brequinar (BQR, DHODH inhibitor), and Selisistat (SEL, SIRT1 inhibitor) were administered, respectively. Subsequently, WB, immunofluorescence was used to determine protein expression and localization, and transmission electron microscopy was used to observe neuronal mitochondrial structure while other indicators of ferroptosis were measured.

RESULTS

MK-4 treatment significantly upregulated the protein levels of DHODH; decreased GSH, PTGS2, NOX1, ROS, and restored mitochondrial membrane potential. Meanwhile, MK-4 upregulated the expression of SIRT1 and promoted its entry into the nucleus. BQR or SEL partially abolished the protective effect of MK-4 on, neurologic function, and ferroptosis.

CONCLUSIONS

Taken together, our results suggest that MK-4 attenuates ferroptosis after SAH by upregulating DHODH through the activation of SIRT1.

GFAP and UCHL1 in Non-traumatic SAH: The Story thus Far. A Systematic Review of the Literature

OBJECTIVE

Non-traumatic subarachnoid hemorrhage (SAH) is associated with a high percentage of misdiagnosis and poor prognosis. Biomarkers could be useful in the identification, treatment/management guidance, and outcome improvement of SAH patients. The current systematic review aims to investigate the potential role of biomarkers GFAP (Glial Fibrillary Acidic Protein) and UCH-L1 (Ubiquitin C-Terminal Hydrolase L1) in the diagnosis and prognosis of non-traumatic SAH.

METHODS

A systematic search of PubMed, Scopus, and Web of Science databases was conducted from their inception through February 2023.

RESULTS

17 studies met the inclusion criteria and were included in this review. The vast majority of the included studies (82%) were on GFAP. Most studies used blood and/or CSF samples and incorporated multiple measurements through the initial hospitalization days. The majority of identified studies reported significantly higher levels of GFAP and UCHL1 in SAH patients with poor outcomes. There was notable variation in the specimen type and the timing of sampling.

CONCLUSION

Quantification of GFAP and UCHL1 through the initial days of hospitalization shows promise in the prediction of SAH patient outcomes. Further research is nevertheless warranted to confirm these findings and further clarify the use of the two biomarkers in SAH diagnosis and the prediction of severity and secondary events.

Regulatory T Cells Secrete IL10 to Suppress Neuroinflammation in Early Stage after Subarachnoid Hemorrhage

Objective: Accumulating evidence supports neuroprotective effects of regulatory T cells (Tregs) in response to brain injury. However, the precise mechanisms underlying the beneficial effects of Tregs on suppressing neuroinflammation after subarachnoid hemorrhage (SAH) remain unclear. Methods: We performed flow cytometry to detect the infiltration of Tregs into the brain at different time points after SAH. Behavioral tests, including Adhesive and Rotarod, were performed to assess neurological deficits in mice after SAH. Bulk RNA sequencing was used to investigate the transcriptomic change of Tregs infiltrating into the brain after SAH. qPCR was performed to verify the variation of inflammatory cytokines expression in the brain after Tregs exogenous infusion. FoxP3-DTR mice and Il10 gene KO mice were used to explore the mechanism of Tregs inhibiting neuron apoptosis after infiltrating the brain following SAH onset. Results: Peripheral Tregs infiltrated into the brain one day after SAH and gradually accumulated in the hemorrhagic hemisphere. An exogenous infusion of Tregs significantly improved the neurological function of mice after SAH, while poor recovery of neurological function was observed in Tregs depletion mice. Transcriptome sequencing data suggested that the immunosuppressive function of brain-infiltrated Tregs was significantly upregulated. qPCR showed that the expression of pro-inflammatory cytokines decreased in the brain of SAH mice after exogenous Tregs infusion. Bioinformatic analysis revealed that IL-10 and other cytokines secreted by brain-infiltrated Tregs were upregulated after SAH. Moreover, exogenous infusion of Il10 gene KO Tregs did not totally improve neurological function in SAH mice. Conclusions: Tregs infiltrated into the brain in the early stage after SAH and exerted neuroprotective effect by secreting IL-10 to suppress neuroinflammation and reduce neuron apoptosis.

The efficacy of antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Aim

The efficacy of antifibrinolytics in subarachnoid hemorrhage remains unclear due to conflicting evidence from studies.

Materials & methods

Online databases were queried to include randomized controlled trials and propensity matched observational studies. We used Review Manager for the statistical analysis, presenting results as odds ratios with 95% CI.

Results

The 12 shortlisted studies included 3359 patients, of which 1550 (46%) were in the intervention (tranexamic acid) group and 1809 (54%) in the control group. Antifibrinolytic therapy significantly reduced the risk of rebleeding (OR: 0.55; 95% CI: 0.40-0.75; p = 0.0002) with no significant decrease in poor clinical outcome (OR: 1.02; 95% CI: 0.86-1.20; p = 0.85) and all-cause mortality (OR: 0.92; CI: 0.72-1.17; p = 0.50).

Conclusion

In patients with subarachnoid hemorrhage, antifibrinolytics reduce the risk of rebleeding without significantly affecting mortality or clinical outcomes.

A Blood-Responsive AIE Bioprobe for the Ultrasensitive Detection and Assessment of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a severe subtype of stroke caused by the rupturing of blood vessels in the brain. The ability to accurately assess the degree of bleeding in an SAH model is crucial for understanding the brain-damage mechanisms and developing therapeutic strategies. However, current methods are unable to monitor microbleeding owing to their limited sensitivities. Herein, a new bleeding assessment system using a bioprobe TTVP with aggregation-induced emission (AIE) characteristics is demonstrated. TTVP is a water-soluble, small-molecule probe that specifically interacts with blood. Taking advantage of its AIE characteristics, cell membranes affinity, and albumin-targeting ability, TTVP fluoresces in bleeding areas and detects the presence of blood with a high signal-to-noise (S/N) ratio. The degree of SAH bleeding in an endovascular perforation model is clearly evaluated based on the intensity of the fluorescence observed in the brain, which enables the ultrasensitive detection of mirco-bleeding in the SAH model in a manner that outperforms the current imaging strategies. This method serves as a promising tool for the sensitive analysis of the degree of bleeding in SAHs and other hemorrhagic diseases.

Validation of the German version of the subarachnoid haemorrhage outcome tool (SAHOT)

Objective:

The subarachnoid haemorrhage (SAH) outcome tool (SAHOT) is the first SAH-specific patient reported outcome measure, and was developed in the UK. We aimed to validate the SAHOT outside the UK, and therefore endeavored to adapt the SAHOT into German and to test its psychometric properties.

Methods:

We adapted and pilot tested the German version. We applied the SAHOT, Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, and EuroQol questionnaires in a cohort of 89 patients with spontaneous SAH after discharge. We assessed internal consistency by Cronbach’s α, test-retest reliability by intraclass correlation, and validity by Pearson correlations with established measures. Sensitivity to change was evaluated following neurorehabilitation by effect sizes.

Results:

The translation of SAHOT resulted in a German version that is semantically and conceptually equivalent to the English version. Internal consistency was good regarding the physical domain (α = 0.83) and excellent for the other domains (α = 0.92–0.93). Test–retest reliability indicated a high level of stability with an intraclass correlation of 0.85 (95% CI: 0.83–0.86). All domains correlated moderately or strongly with established measures ( r = 0.41–0.74; p < 0.01). SAHOT total scores showed moderate sensitivity to change (Cohen’s d = −0.68), while mRS and GOSE showed no significant sensitivity to change.

Conclusion:

The SAHOT can be adapted to other health care systems and societies than the UK. The German version of the SAHOT is a reliable and valid instrument, and can be used in future clinical studies and individual assessment after spontaneous SAH.

Prioritizing outcome measures after aneurysmal subarachnoid hemorrhage: A q-sort survey of patients, health care providers and researchers

Objective

To understand which outcome measures patients and their families, health care providers, and researchers prioritize after aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We conducted a cross-sectional q-sort survey with participants from three key stakeholder groups. Potential outcomes were identified from interviews and focus groups. Participants were purposively sampled to achieve diversity based on stakeholder group, geography, and profession. Respondents sorted 27 outcomes in a quasi-normally distributed grid (Q-Sort) from most to least important. Principal components analysis was used to determine similarities in the way participants sorted the outcome measures resulting in distinct groupings. Overall rankings were also reported.

Results

112 participants were invited. 70 responded and 64 participants from 25 different countries completed a Q-sort. Balanced stakeholder representation was achieved. Five distinct patterns were identified based on survival, pathophysiological, psychological, resource use, and functional outcome measures. Quality of life as reported by the patient was the highest ranked outcome measure followed by independence and functional measures. Survival and biomedical outcomes were ranked in the middle and cost measures last.

Conclusions

In this diverse sample of key stakeholders, we characterized several distinct perspectives with respect to outcome measure selection in aSAH. We did not identify a clear pattern of opinion based on stakeholder group or other participant characteristics. Patient-reported measure of quality of life was ranked the most important overall with function and independence also highly rated. These results will assist study design and inform efforts to improve outcome selection in aSAH research.

Endothelial NOX4 aggravates eNOS uncoupling by decreasing dihydrofolate reductase after subarachnoid hemorrhage

Endothelial malfunction is a major contributor to early or delayed vasospasm after subarachnoid hemorrhage (SAH). As a representative form of endothelial dysfunction, endothelial nitric oxide synthase (eNOS) uncoupling leads to a reduction in nitric oxide (NO) generated by endothelial cells. In this study, we investigated how the interaction between endothelial NOX4 (nicotinamide adenine dinucleotide phosphate oxidase 4) and DHFR (dihydrofolate reductase) contributes to eNOS uncoupling after SAH. Setanaxib and the adeno-associated virus (AAV) targeting brain vascular endothelia were injected through the tail vein and the expression and localization of proteins were examined by western blot and immunofluorescence staining. The NO content was measured using the NO assay kit, and laser speckle contrast imaging was used to assess cortical perfusion. ROS (reactive oxygen species) level was detected by DHE (dihydroethidium) staining, DCFH-DA (2',7'-dichlorofluorescin diacetate) staining and H₂O₂ (hydrogen peroxide) measurement. The Garcia score was employed to examine neurological function. Setanaxib is widely used for its preferential inhibition for NOX1/4 over other NOX isoforms. After endothelial NOX4 was inhibited by Setanaxib in a mouse model of SAH, the endothelial DHFR level was significantly elevated, which attenuated eNOS uncoupling, increased cortical perfusion, and improved the neurological function. The protective role of inhibiting endothelial NOX4, however, disappeared after knocking down endothelial DHFR. Our results suggest that endothelial DHFR decreased significantly because of the elevated level of endothelial NOX4, which aggravated eNOS uncoupling after SAH, leading to decreased cortical perfusion and worse neurological outcome.

Made to measure—Selecting outcomes in aneurysmal subarachnoid hemorrhage research

There has been limited new high-level evidence generated to guide aneurysmal subarachnoid hemorrhage (aSAH) management in the past decade. The choice of outcome measures used in aSAH clinical trials may be one of the factors hindering progress. In this narrative review we consider the current process for determining “what” to measure in aSAH and identify some of the shortcomings of these approaches. A consideration of the unique clinical course of aSAH is then discussed and how this impacts on selecting the best timepoints to assess change in the chosen constructs. We also review the how to critically appraise different measurement instruments and some of the issues with how these are applied in the context of aSAH. We conclude with current initiatives to improve outcome selection in aSAH and future directions in the research agenda.

Rethinking the initial changes in subarachnoid haemorrhage: Focusing on real-time metabolism during early brain injury

Over the last two decades, neurological researchers have uncovered many pathophysiological mechanisms associated with subarachnoid haemorrhage (SAH), with early brain injury and delayed cerebral ischaemia both contributing to morbidity and mortality. The current dilemma in SAH management inspired us to rethink the nature of the insult in SAH: sudden bleeding into the subarachnoid space and hypoxia due to disturbed cerebral circulation and increased intracranial pressure, generating exogenous stimuli and subsequent pathophysiological processes. Exogenous stimuli are defined as factors which the brain tissue is not normally exposed to when in the healthy state. Intersections of these initial pathogenic factors lead to secondary brain injury with related metabolic changes after SAH. Herein, we summarized the current understanding of efforts to monitor and analyse SAH-related metabolic changes to identify those precise pathophysiological processes and potential therapeutic strategies; in particular, we highlight the restoration of normal cerebrospinal fluid circulation and the normalization of brain-blood interface physiology to alleviate early brain injury and delayed neurological deterioration after SAH.

The Role of Circadian Clock Genes in Critical Illness: The Potential Role of Translational Clock Gene Therapies for Targeting Inflammation, Mitochondrial Function, and Muscle Mass in Intensive Care

The Earth's 24-h planetary rotation, with predictable light and heat cycles, has driven profound evolutionary adaptation, with prominent impacts on physiological mechanisms important for surviving critical illness. Pathways of interest include inflammation, mitochondrial function, energy metabolism, hypoxic signaling, apoptosis, and defenses against reactive oxygen species. Regulation of these by the cellular circadian clock (BMAL-1 and its network) has an important influence on pulmonary inflammation; ventilator-associated lung injury; septic shock; brain injury, including vasospasm; and overall mortality in both animals and humans. Whether it is cytokines, the inflammasome, or mitochondrial biogenesis, circadian medicine represents exciting opportunities for translational therapy in intensive care, which is currently lacking. Circadian medicine also represents a link to metabolic determinants of outcome, such as diabetes and cardiovascular disease. More than ever, we are appreciating the problem of circadian desynchrony in intensive care. This review explores the rationale and evidence for the importance of the circadian clock in surviving critical illness.

Abnormal Schwannoma-like Growth of multiple, multifocal BRAF V600E-positive Glioblastoma in the Interior Acoustic Canal with Leptomeningeal Infiltration: a case report

Background

Glioblastoma belongs to the most common and most aggressive tumor entity of the central nervous system with a poor prognosis of only few months. Once manifested, it grows fast and diffusely by infiltrating the surrounding brain parenchyma. Despite its aggressive behavior, glioblastoma rarely presents with multiple lesions and metastasis to intra- and extracranial tissues. Therefore, metastasized, multiple glioblastoma is limited to case reports. Our case describes an atypical primary bilateral manifestation of BRAF V600E-positive epithelioid glioblastoma with rapid metastasis and meningeosis glioblastoma while under adjuvant chemoradiotherapy.

Case presentation

A 60-year-old Caucasian male patient presented with a seizure and numbness in his left arm. He was diagnosed with an abnormal primary bilateral manifestation of multiple, multifocal BRAF V600E-positive and isocitrate dehydrogenase (IDH) wild-type intracranial epithelioid glioblastoma with O⁶-methylguanine-DNA methyltransferase methylation (MGMT) at 12%. While being under the adjuvant chemoradiotherapy with temozolomide, the patient developed left-sided facial nerve weakness and hearing loss, dysarthria, and severe gait instability. Cranial magnetic resonance imaging showed that glioblastoma lesions advanced rapidly with a schwannoma-like growth pattern by invading the left internal acoustic meatus, adjacent cranial nerves, and leptomeninges. A lumbar puncture confirmed meningeosis glioblastoma. Four months after the initial diagnosis of glioblastoma, the patient died from the complications of the fast and diffuse metastasis.

Conclusions

Glioblastoma rarely presents with metastases despite its aggressive and rapidly growing nature. Our case should increase awareness of symptom tracking in patients with glioblastoma to intervene early and efficiently. Moreover, refractory therapies for glioblastoma should underline the importance of personalized medicine.

Beyond Functional Impairment: Redefining Favorable Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

For outcome assessment in patients surviving subarachnoid hemorrhage (SAH), the modified Rankin scale (mRS) represents the mostly established outcome tool, whereas other dimensions of outcome such as mood disorders and impairments in social life remain unattended so far.

OBJECTIVE

The aim of our study was to correlate 12-month functional and subjective health outcomes in SAH survivors.

METHODS

All SAH patients treated over a 5-year period received outcome assessment at 12 months, including functional scores (mRS and Barthel Index [BI]), subjective health measurement (EQ-5D), and whether they returned to work. Analyses - including utility-weighted mRS - were conducted to detect associations and correlations among different outcome measures, especially in patients achieving good functional outcome (i.e., mRS 0-2) at 12 months.

RESULTS

Of 351 SAH survivors, 287 (81.2%) achieved favorable functional outcome at 12 months. Contrary to the BI, the EQ-5D visual analog scale (VAS) showed a strong association with different mRS grades, accentuated in patients with favorable functional outcome. Despite favorable functional outcome, patients reported a high rate of impairments in activities (24.0%), pain (33.4%), and anxiety/depression (42.5%). Further, multivariable analysis revealed (i) impairments in activities (odds ratio [OR] [95% confidence interval {CI}]: 0.872 [0.817-0.930]), (ii) presence of depression or anxiety (OR [95% CI]: 0.836 [0.760-0.920]), and (iii) return to work (OR [95% CI]: 1.102 [0.1.013-1.198]) to be independently associated with self-reported subjective health.

CONCLUSION

Established stroke scores mainly focusing on functional outcomes do poorly reflect the high rate of subjective impairments reported in SAH survivors, specifically in those achieving good functional outcome. Further studies are needed to investigate whether psychoeducational approaches aiming at improving coping mechanisms and perceived self-efficacy may result in higher subjective health in these patients.

Neuromonitoring with near-infrared spectroscopy (NIRS) in aneurysmal subarachnoid haemorrhage: a systematic review protocol

INTRODUCTION

Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating disease associated with high mortality and morbidity. The main threat to patients is delayed cerebral ischaemia (DCI). Near-infrared spectroscopy (NIRS) is a recent technology allowing continuous, non-invasive cerebral oximetry that could permit timely detection of impending DCI and appropriate intervention to improve outcomes. However, the ability of regional oxygen saturation to detect DCI, its association to the outcome, or benefits of any interventions based on NIRS data, are lacking. Our aims are to evaluate NIRS technology both as a therapeutic tool to improve outcomes in aSAH patients and as a diagnostic tool for DCI.

METHODS AND ANALYSIS

MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews will be searched from their inception and without language restriction. Our search strategy will cover the themes of subarachnoid haemorrhage and cerebral oximetry, without limitations regarding studied outcomes. We will identify all observational and interventional human studies of adult patients hospitalised after aSAH that were monitored using NIRS. Functional outcome measures, including the modified Rankin Scale, the Glasgow Outcome Scale and the Barthel Index, will constitute the primary outcome. The Cochrane Risk of Bias tool will be used for randomised controlled trials, the ROBINS-I tool to assess non-randomised studies of interventions and the Newcastle-Ottawa Scale for cohort or case-control studies. The Quality Assessment of Diagnostic Accuracy Studies-2 will be applied to studies evaluating NIRS diagnostic accuracy for DCI. We will evaluate the quality of the evidence of the effect based on the Grading of Recommendations Assessment, Development and Evaluation methodology.

ETHICS AND DISSEMINATION

Dissemination will proceed through submission for journal publication, trial registry completion and abstract presentation. Ethics approval is not required.

PROSPERO REGISTRATION NUMBER

CRD42020077522.