Aneurysmal Subarachnoid Hemorrhage: the Last Decade

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.

Therapeutic potential of stem cells in subarachnoid hemorrhage

Aneurysm rupture can result in subarachnoid hemorrhage, a condition with potentially severe consequences, such as disability and death. In the acute stage, early brain injury manifests as intracranial pressure elevation, global cerebral ischemia, acute hydrocephalus, and direct blood-brain contact due to aneurysm rupture. This may subsequently cause delayed cerebral infarction, often with cerebral vasospasm, significantly affecting patient outcomes. Chronic complications such as brain volume loss and chronic hydrocephalus can further impact outcomes. Investigating the mechanisms of subarachnoid hemorrhage-induced brain injury is paramount for identifying effective treatments. Stem cell therapy, with its multipotent differentiation capacity and anti-inflammatory effects, has emerged as a promising approach for treating previously deemed incurable conditions. This review focuses on the potential application of stem cells in subarachnoid hemorrhage pathology and explores their role in neurogenesis and as a therapeutic intervention in preclinical and clinical subarachnoid hemorrhage studies.

Preventive effect of aminocaproic acid combined with nimodipine on short-term rebleeding in patients with aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening and life-limiting disease with high mortality and disability rates. Herein, we aim to explore the preventive effect of aminocaproic acid combined with nimodipine on short-term rebleeding in patients with aSAH. Retrospectively, the medical data of patients with aSAH ( n  = 256) were collected. According to different treatment methods, patients were categorized into the aminocaproic acid + nimodipine group ( n  = 152) and the nimodipine group ( n  = 104), and were treated for 1 week. Baseline characteristics, incidence of rebleeding, average velocity of cerebral artery blood flow, cerebral vasospasm index, vascular endothelial function, complications, and adverse events were analyzed between the two groups. After 1-week treatment, compared to the nimodipine group, the aminocaproic acid + nimodipine group exhibited lower incidence of rebleeding, notable decreases in average velocity of cerebral artery blood flow and the cerebral vasospasm index, and downregulation of endothelin-1 and vascular endothelial growth factor ( P  < 0.05). There were no significant differences about complications and adverse events between the two groups. Aminocaproic acid combined with nimodipine is superior to nimodipine alone in preventing the short-term rebleeding in patients with aSAH, and has good safety.

Pharmacological inhibition of P2RX4 receptor as a potential therapeutic strategy to prevent intracranial aneurysm formation

Intracranial aneurysms (IA) affect 1-5 % of the population and are a major cause of subarachnoid hemorrhage. Thus, preventing IA development and progression is crucial for public health. IA has been considered a non-physiological, high shear stress-induced chronic inflammatory disease affecting the bifurcation site of the intracranial arteries. Therefore, factors that sense high shear stress and induce IAs by triggering inflammation could potentially act as therapeutic targets. P2RX4 is a member of the purinoreceptor family that converts the strength of shear stress into intracellular signals. To verify its therapeutic potential, we investigated the effects of P2RX4 and a selective antagonist on the formation of IAs. Results showed that P2RX4 deficiency significantly suppressed the formation of IAs. Consistently, the selective P2RX4 antagonist NC-2600, which potently inhibited Ca2+ influx in response to shear-stress loading in endothelial cells in vitro, significantly suppressed the formation of IAs. The results of the present study contribute to our understanding of the pathogenesis of IAs and may provide benefits to society through the future development of medical therapies targeting P2RX4.

Hyperoxia and unfavourable outcome in patients with non-traumatic subarachnoid haemorrhage: A systematic review and meta-analysis

BACKGROUND

It is common practice to administer oxygen to neurocritical patients in the Intensive Care Unit (ICU). Consequent hyperoxia has been associated with unfavourable outcomes including in patients with brain injury, after cardiac arrest, sepsis, and traumatic brain injury. The aim of this systematic review was to explore the association between hyperoxia exposure and unfavourable outcome in patients following a non-traumatic subarachnoid haemorrhage (SAH).

METHODS

Systematic searches of Medline, Embase, Emcare, CINAHL and PubMed were performed in February 2024 using key words for SAH and hyperoxia. Non-human studies, articles in languages other than English, studies that did not measure blood oxygenation levels via pulse oximetry or arterial blood gas analyses, and studies exploring traumatic SAH were excluded. The Newcastle-Ottawa Risk of Bias tool (NOS) was used to assess the quality of included manuscripts. The primary outcome was a composite outcome combining mortality or poor functional neurological outcome. Secondary outcomes included mortality, poor functional neurological outcome, and development of delayed cerebral ischaemia (DCI).

RESULTS

The literature search yielded 1,219 non-duplicate articles published after 1 January 2000, of which 21 articles were reviewed as full-texts and nine were included in this review. All included studies were rated good/high quality using the NOS. Hyperoxia exposure was associated with increased risk of adverse composite outcome of death or unfavourable functional neurological outcome (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.19-2.16), poor functional neurological outcome alone (OR 1.79, 95% CI 1.33-2.42) and development of DCI (OR 2.63, 95% CI 1.79-3.85). The association of hyperoxia and hospital mortality alone was not statistically significant (OR 1.42, 95% CI 0.98-2.04).

CONCLUSION

Hyperoxia may contribute to unfavourable outcomes and the development of DCI after an non-traumatic SAH. Trials using restrictive oxygen therapy among patients with SAH are indicated.

Multifaceted role of thrombin in subarachnoid hemorrhage: Focusing on cerebrospinal fluid circulation disorder

Subarachnoid hemorrhage (SAH) is a severe neurological condition characterized by high morbidity and mortality. The unfavorable prognosis of SAH is closely associated with early brain injury (EBI) and delayed cerebral ischemia (DCI), wherein thrombin plays a role as part of the secondary injury components following hemorrhage in these two pathological processes. Additionally, thrombin contributes to disruptions in the circulation of cerebrospinal fluid (CSF), thereby giving rise to a spectrum of sequelae following SAH, including cerebral edema, hydrocephalus, cognitive impairments, and depressive symptoms. This review aims to provide a comprehensive understanding of the pathological role of thrombin in EBI, DCI, and CSF circulation following SAH, with a specific focus on its impact on the glymphatic-meningeal lymphatic system-a crucial mechanism for waste clearance and neurohomeostatic regulation. Additionally, this review offers an overview of current pharmacological interventions and treatment modalities targeting pathogenic mechanisms, aiming to mitigate brain injury and promote neurological recovery post-SAH.

Asiatic acid alleviates subarachnoid hemorrhage-induced brain injury in rats by inhibiting ferroptosis of neurons via targeting acyl-coenzyme a oxidase 1

The occurrence of subarachnoid hemorrhage (SAH) can lead to brain injury, which is a fatal condition with limited effective clinical intervention strategies. The naturally occurring component Asiatic acid (AA), found in the tropical plant Centella asiatica, has been reported to possess neuroprotective properties. The objective of this study was to evaluate the neuroprotective effect of AA following SAH and investigate its potential mechanisms. The SAH model was established in male Sprague-Dawley (SD) rats through intravascular perforation, following a standardized protocol. The administration of AA was performed via gavage following SAH. A lentiviral vector was constructed and utilized for the knockdown of Acyl Coenzyme A Oxidase 1 (ACOX1) Firstly, AA treatment effectively improves brain neurological deficit, neuronal damage, and iron deposition induced by SAH. Furthermore, it has been demonstrated that AA directly interacts with ACOX1, which exhibits decreased expression in neurons following SAH. Additionally, our study reveals AA can reverse SAH-induced reduction in ACOX1 expression, concurrently ameliorating neuronal ferroptosis. This improvement is evidenced by reduced lipid peroxidation, including mitigated GSH depletion, decreased MDA production, and increased GPX4 content and activity. Also, AA enhances mitochondrial constriction while alleviating cristae disruption induced by SAH, providing crucial insights into its neuroprotective effects against neuronal ferroptosis in SAH. Moreover, when ACOX1 is knocked down, the neuroprotective effects of AA are weakened. Collectively, this study elucidated the neuroprotective effect of AA by inhibiting neuronal cell ferroptosis through targeting ACOX1. These findings suggest that AA holds promise as a potential therapeutic candidate for ameliorating SAH-induced brain injury.

Enlarged Perivascular Spaces (EPVS) Associated with Functional and Cognitive Outcome After Aneurysm Subarachnoid Hemorrhage (aSAH)

Aneurysmal rupture is the main cause of subarachnoid hemorrhage (SAH), leading to neurological and cognitive deficits. The clinical significance of enlarged perivascular spaces (EPVS) on aSAH (aneurysm subarachnoid hemorrhage) outcomes was unclear. Our aim was to explore the association between EPVS and the clinical outcomes of aSAH. Magnetic resonance imaging (MRI) scans of 195 aSAH survivors were analyzed. Poor outcome was defined as modified Rankin Scale (mRS) ≥ 3. Cognitive outcomes were measured with the Montreal Cognitive Assessment (MoCA). We compared the clinical characteristics of aSAH with EPVS < 10 and EPVS ≥ 10 in basal ganglia (BG) and centrum semiovale (CSO) and investigated the association of EPVS severity and topography with delayed cerebral ischemia (DCI), subacute hydrocephalus, and 3-month unfavorable functional outcome and cognitive status using binary logistic regression model, respectively. At 3 months, 159 patients completed the MoCA assessments, and 63 (39.6%) were diagnosed with cognitive impairment (MoCA < 22). BG-EPVS ≥ 10 was associated with unfavorable functional outcomes at 3 months (odds ratio [OR] 2.426, 95% confidence interval [CI] 1.128-5.216, p < 0.05), subacute hydrocephalus (OR 3.789, 95% CI 1.049-13.093, p < 0.05), and DCI (OR 2.579, 95% CI 1.086-6.123, p < 0.05), but not with cognitive impairment after adjusting for established predictors. CSO-EPVS was linked to unfavorable functional outcomes at 3 months (OR 3.411, 95% CI 1.422-8.195, p < 0.05) and worse cognitive function (OR 2.520, 95% CI 1.136-5.589, p < 0.05). Our cohort study reveals that both BG-EPVS and CSO-EPVS are independently associated with unfavorable functional outcomes after aSAH. However, only CSO-EPVS, not BG-EPVS, is related to cognitive impairment at 3 months.

Risk Score for Early Prediction of In-Hospital Mortality After Aneurysmal Subarachnoid Hemorrhage: Pooled Analysis With Score Construction and Validation

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) has a high complications burden, with in-hospital mortality as the most devastating outcome. We aimed to develop and validate a risk score for early prediction of in-hospital mortality after aSAH.

METHODS

Data from 2 university hospitals were pooled (n = 1070), with cohorts for score construction (n = 886) and external validation (n = 184). Several parameters assessable at admission were collected. Independent predictors of in-hospital mortality were used as mortality score components. Diagnostic accuracy of the novel score was compared to the Hunt and Hess Age, Intraventricular Hemorrhage, Rebleed and World Federation of Neurosurgical Societies (WFNS) scores.

RESULTS

Overall rate of in-hospital mortality was 19% and 14.7% in construction and validation cohorts, respectively. The novel risk score (aSAH mortality score: 0-12 points) included patients' age (≤55 years: 0 points, 56-70 years: 1 point, >70 years: 2 points), aneurysm rebleeding (2 points), WFNS grade (grade I-II: 0 points, grade III-IV: 2 points, grade V: 5 points), and Hijdra sum score (≤10: 0 points, 11-20: 1 point, 21-30: 2 points, >30: 3 points). In-hospital mortality rates ranged 0.6% (0 points) to 100% (12 points) in the construction cohort, and 0% (0 points) to 60% (10 points) in the validation cohort. In the receiver operating characteristic analysis, the aneurysmal subarachnoid hemorrhage mortality score (area under the curve [AUC]: 0.829 and 0.824 in the construction and validation cohorts, respectively) was superior to the Hunt and Hess Age, Intraventricular Hemorrhage, Rebleed (AUC: 0.811 and 0.813) and WFNS scores (AUC: 0.768 and 0.795).

CONCLUSIONS

Risk of in-hospital mortality after aSAH can be predicted with high accuracy using baseline characteristics. The novel risk score showed best diagnostic performance in the construction and validation cohorts and can aid in early prognostication and treatment decisions.

Perivascular Neutrophil Extracellular Traps Exacerbate Microvasospasm After Experimental Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) can lead to acute or delayed cerebral ischemia. Recent findings have revealed that spasm of microvessels, called microvasospasm, may contribute to SAH-related cerebral ischemia, and perivascular inflammation is considered important in the development of microvasospasms. However, owing to the difficulty in investigating the dynamics of vascular and perivascular events, little is known about the mechanisms underlying microvasospasms.

METHODS

We established an experimental system aiming to investigate the vascular and perivascular pathology of SAH by combining a SAH mouse model with intravital 2-photon imaging. SAH was induced by intracisternal blood injection, and the distribution of erythrocytes, neutrophil behavior, and morphological changes in the pial arterioles were analyzed over time by 2-photon microscopy imaging. To further explore the role of neutrophils and neutrophil extracellular traps (NETs) in microvasospasm, we performed neutrophil depletion by intraperitoneal administration of neutrophil-specific antibody or NETs removal by intracisternal administration of DNase.

RESULTS

Erythrocytes were immediately distributed in the perivascular space of the arterioles after SAH induction; neutrophils intensively infiltrated the perivascular space within 2 days and subsequently showed NETosis; and pial arterioles in the same region developed pearl-string-like microvasospasms in the subacute phase. Neutrophil depletion significantly reduced the number of microvasospasms. Furthermore, the removal of perivascular NETs drastically reduced microvasospasms.

CONCLUSIONS

By establishing a unique experimental system, we demonstrated that perivascular NETs could be a new therapeutic target for microvasospasms.

Predictors of survival after aneurysmal subarachnoid hemorrhage: The long-term observational cohort study

OBJECTIVE

Despite recent advances in neuro-intensive care, there is still considerable mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). In this long-term monocentric observational cohort study, we aimed to analyze the rates, timing, and predictors of mortality after SAH.

METHODS

All consecutive SAH cases treated between January 2003 and June 2016 were included. Patients' demographic characteristics, previous medical history, SAH-related parameters, and available post-treatment follow-up data were collected and evaluated as potential mortality predictors in univariate and multivariate analyses.

RESULTS

Of 992 patients, 179 died during the initial treatment and 33 during the follow-up time reaching an overall mortality rate of 21.4 %. Of over 119 tested variables, we identified the following independent predictors in the final multivariate Cox regression analysis: age >55 years (p<0.0001); World Federation of Neurosurgical Societies (WFNS) admission grade IV or V (p=0.025); Hijdra sum score ≥15 points (p=0.003); intracranial pressure (ICP) increase (p<0.0001); and delayed cerebral ischemia (DCI) (p<0.0001). Being exposed to all five risk factors resulted in the case fatality rate of 75 % within a median survival of 14 days, compared to 2.5 % within a median of 1525 days when none of these features were present.

CONCLUSIONS

The initial impact of aneurysmal bleeding is amongst the major mortality causes after SAH. Of potentially preventable adverse events, ICP increase and DCI occurring during initial treatment also present eminent clinical relevance for patients' survival in the long-term follow-up. Further ICP and DCI management optimization might help to decrease the mortality rate after SAH.

Iron Metabolism and Ferroptosis in Early Brain Injury after Subarachnoid Haemorrhage

At present, it appears that the prognosis for subarachnoid haemorrhage (SAH), which has a high death and disability rate, cannot be greatly improved by medication or other treatment. Recent research suggests that different types of cell death are implicated in early brain injury (EBI) after SAH, and this has been recognised as a major factor impacting the prognosis of SAH. Ferroptosis, which is a recently identified imbalance of iron metabolism and programmed cell death triggered by phospholipid peroxidation, has been shown to be involved in EBI after SAH and is thought to have a significant impact on EBI. The decomposition of cleaved haemoglobin during SAH involves the release of enormous amounts of free iron, resulting in iron metabolism disorders. Potential therapeutic targets for the signalling pathways of iron metabolism disorders and ferroptosis after SAH are constantly being discovered. To serve as a guide for research into other possible therapeutic targets, this paper will briefly describe the mechanisms of dysregulated iron metabolism and ferroptosis in the pathogenesis of SAH and highlight how they are involved in the development and promotion of EBI in SAH.

The effect of green channel for stroke patients on treatment of severe aneurysmal subarachnoid hemorrhage

PURPOSE

To explore the effect of green channel for stroke patients on the treatment of severe aneurysmal subarachnoid hemorrhage.

METHODS

This is a retrospective case-control study. The clinical data of patients with severe aneurysmal subarachnoid hemorrhage admitted to the emergency department of our hospital from January 2015 to June 2022 were retrospectively analyzed. Patients diagnosed with subarachnoid hemorrhage, confirmed intracranial aneurysm by preoperative CT angiography or digital subtraction, graded Hunt-Hess grade III, IV, and V, < 72 h from the onset to the time of consultation received surgical treatment in our hospital were included in this study. Patients with serious underlying diseases, such as heart, liver, kidney diseases, or malignant tumors, traumatic subarachnoid hemorrhage, previous history of cerebral hemorrhage, and incomplete data were excluded. The control group included patients with severe aneurysmal subarachnoid hemorrhage admitted from January 2015 to December 2018 before the establishment of the green channel for stroke patients, and the observation group included patients with severe aneurysmal subarachnoid hemorrhage admitted from January 2019 to June 2022 after the establishment of the green channel. The control group received routine treatment in the emergency department; the observation group received improved treatment of green channel for stroke patients. Gender, age, Hunt-Hess grade on admission, modified Rankin scale (mRS) on admission, aneurysm location, aneurysm size and whether accompanied by intracerebral hemorrhage, the time from onset to emergency department, the time from emergency department to vascular diagnostic examination, the time from onset to surgery, the time from emergency department to surgery, the time from hospital admission to surgery, length of hospital stay, complications, treatment effect were analyzed and compared between the 2 groups. SPSS 23.0 software was utilized to conduct comparisons between the 2 groups. The t-test, Chi-square test, or Mann-Whitney U test was chosen based on the data type. Statistical significance was established when p < 0.05.

RESULTS

A total of 71 patients were included in this study, of whom 37 were in the control group and 34 were in the observation group. There were no statistical differences in age, gender, Hunt-Hess grade, mRS scores, aneurysm location, aneurysm size, intracerebral hemorrhage, the time from onset to emergency department, length of hospital stay, complications between the observation group and the control group (all p > 0.05). The time (min) from visit to vascular diagnostic test (60.50 vs. 120.00, p = 0.027), the time (min) from onset to surgery (1792.00 vs. 2868.00, p = 0.023), the time (min) from emergency department to surgery (1568.50 vs. 2778.00, p = 0.016), the time (min) from hospital admission to surgery (1188.50 vs. 2708.00, p = 0.043), all of them were shorter in the observation group than those in the control group. The relative values of admission and 7-day postoperative mRS scores and the relative values of admission and discharge mRS scores ≥ 2 were used as the criteria for determining better efficacy, and the treatment effect was better than that in the control group, and the differences were statistically significant (admission to 7 days postoperative mRS score ≥ 2, 17 (50.0 %) vs. 8 (21.6 %), p = 0.012; admission to discharge mRS score ≥ 2, 19 (55.9 %) vs. 11 (29.7 %), p = 0.026).

CONCLUSION

The green channel for stroke patients with severe aneurysmal subarachnoid hemorrhage can effectively shorten the time from arrival at the emergency department to vascular diagnostic examination and the time from the emergency department to surgery, and achieve a better therapeutic effect, which is worth popularizing and applying.

Efficacy and Safety of Early Treatment with Glibenclamide in Patients with Aneurysmal Subarachnoid Hemorrhage: A Randomized Controlled Trial

BACKGROUND

This study aims to investigate the efficacy and safety of glibenclamide treatment in patients with acute aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

The randomized controlled trial was conducted from October 2021 to May 2023 at two university-affiliated hospitals in Beijing, China. The study included patients with aSAH within 48 h of onset, of whom were divided into the intervention group and the control group according to the random number table method. Patients in the intervention group received glibenclamide tablet 3.75 mg/day for 7 days. The primary end points were the levels of serum neuron-specific enolase (NSE) and soluble protein 100B (S100B) between the two groups. Secondary end points included evaluating changes in the midline shift and the gray matter-white matter ratio, as well as assessing the modified Rankin Scale scores during follow-up. The trial was registered at ClinicalTrials.gov (identifier NCT05137678).

RESULTS

A total of 111 study participants completed the study. The median age was 55 years, and 52% were women. The mean admission Glasgow Coma Scale was 10, and 58% of the Hunt-Hess grades were no less than grade III. The baseline characteristics of the two groups were similar. On days 3 and 7, there were no statistically significant differences observed in serum NSE and S100B levels between the two groups (P > 0.05). The computer tomography (CT) values of gray matter and white matter in the basal ganglia were low on admission, indicating early brain edema. However, there were no significant differences found in midline shift and gray matter-white matter ratio (P > 0.05) between the two groups. More than half of the patients had a beneficial outcome (modified Rankin Scale scores 0-2), and there were no statistically significant differences between the two groups. The incidence of hypoglycemia in the two groups were 4% and 9%, respectively (P = 0.439).

CONCLUSIONS

Treating patients with early aSAH with oral glibenclamide did not decrease levels of serum NSE and S100B and did not improve the poor 90-day neurological outcome. In the intervention group, there was a visible decreasing trend in cases of delayed cerebral ischemia, but no statistically significant difference was observed. The incidence of hypoglycemia did not differ significantly between the two groups.

Comprehensive Management of Intracranial Aneurysms Using Artificial Intelligence: An Overview

Intracranial aneurysms (IAs), an asymptomatic vascular lesion, are becoming increasingly common as imaging technology progresses. Subarachnoid hemorrhage from IAs rupture entails a substantial risk of mortality or severe disability. The early detection and prompt intervention of IAs posing a high risk of rupture are paramount for optimizing clinical management and safeguarding patients' lives. Artificial intelligence (AI), with its exceptional capabilities in image-based tasks, has garnered significant scholarly interest worldwide. Its application in the management of IAs holds promise for advancing medical research and patient care. Utilizing deep learning algorithms, AI exhibits remarkable capabilities in precisely identifying and segmenting aneurysms, significantly enhancing diagnostic sensitivity and accuracy. Furthermore, AI can meticulously analyze extensive aneurysm datasets to forecast aneurysm growth, rupture hazards, and prognostic scenarios, offering clinician's invaluable assistance in decision-making. This article comprehensively examines the latest advancements in the utilization of AI in aneurysm treatment, encompassing detection and segmentation, rupture risk assessment, prediction of therapeutic outcomes, and facilitation of microcatheter shaping. A brief discussion is held on the challenges and future paths for clinical AI deployments.

Risk identification for the development of large-artery vasospasm after aneurysmatic subarachnoid hemorrhage - a multivariate, risk-, and location-adjusted prediction model

BACKGROUND

Vasospasm of the large cerebral arteries (CVS) after aneurysmatic subarachnoid hemorrhage (aSAH) reduces cerebral perfusion and causes delayed cerebral ischemia. Although endovascular spasmolysis shows convincing angiographic results, patients often do not improve in outcome. Delayed recognition of CVS contributes substantially to this effect. Therefore, this study aimed to confirm established and to identify unknown risk factors for CVS, which can be used for risk stratification.

METHODS

In this monocentric, retrospective cohort study of 853 patients with aSAH, we compared demographics, clinical, and radiographic parameters at the time of aneurysm occlusion between patients who developed CVS and those who did not. Significant cohort differences were included as predictors in a multivariate analysis to address confounding. Logistic regression models were used to determine odds ratios (ORs) for the presence of CVS for each predictor.

RESULTS

Of the 853 patients treated with aSAH, 304 (32%) developed CVS. In the univariable analysis, CVS was significantly associated with young age, female sex, aneurysm location, modified Fisher score, Barrow Neurological Institute (BNI) score, and surgical interventions. In the multivariable regression analysis, we identified BNI score (OR 1.33, 95% CI 1.11 to 1.58, p=0.002), decompressive craniectomy (OR 1.93, 95% CI 1.22 to 3.04, p=0.005), and aneurysm clipping (OR 2.22, 95% CI 1.50 to 3.29, p<0.001), as independent risk factors.

CONCLUSIONS

Young female patients with high BNI scores who undergo surgical interventions are more likely to develop CVS and should therefore be monitored most intensively after aneurysm occlusion.

Inhibition of acid-sensing receptor GPR4 attenuates neuronal ferroptosis via RhoA/YAP signaling in a rat model of subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) is a devastating stroke, in which acidosis is one of detrimental complications. The extracellular pH reduction can activate G protein-coupled receptor 4 (GPR4) in the brain. Yet, the extent to which proton-activated GPR4 contributes to the early brain injury (EBI) post-SAH remains largely unexplored. Ferroptosis, iron-dependent programmed cell death, has recently been shown to contribute to EBI. We aimed to investigate the effects of GPR4 inhibition on neurological deficits and neuronal ferroptosis after SAH in rats.

METHODS

A total 253 Sprague Dawley (SD) male rats (weighing 275-330g) were utilized in this study. SAH was induced by endovascular perforation. NE-52-QQ57 (NE), a selective antagonist of GPR4 was administered intraperitoneally 1-h post-SAH. To explore the mechanisms, RhoA activator U-46619 and YAP activator PY-60 were delivered intracerebroventricularly. Short- and long-term neurobehavior, SAH grading, Western blot assay, ELISA assay, immunofluorescence staining, and transmission electron microscopy was performed post-SAH.

RESULTS

Following SAH, there was an upregulation of GPR4 expression in neurons. GPR4 inhibition by NE improved both short-term and long-term neurological outcomes post-SAH. NE also reduced neuronal ferroptosis, as evidenced by decreased lipid peroxidation products 4HNE and MDA levels in brain tissues, and reduced mitochondrial shrinkage, increased mitochondria crista and decreased membrane density. The application of either U-46619 or PY-60 partially offset the neuroprotective effects of NE on neuronal ferroptosis in SAH rats.

CONCLUSIONS

This study demonstrated that acid-sensing receptor GPR4 contributed to neuronal ferroptosis after SAH via RhoA/YAP pathway, and NE may be a potential therapeutic strategy to attenuate GPR4 mediated neuronal ferroptosis and EBI after SAH.

Method for detection of cerebral blood flow in neurointensive care using longitudinal arterial spin labeling MRI

Cerebral blood flow (CBF) is carefully monitored in the Neurointensive Care Unit (NICU) to prevent secondary brain insults in patients who have suffered subarachnoid hemorrhage. Including absolute MRI measurements of CBF in the NICU monitoring protocol could add valuable information and potentially improve patient outcomes. This is particularly feasible at Linköping University Hospital, which uniquely has an MRI scanner located in the NICU, enabling longitudinal CBF measurements while eliminating medical transportation risks. Arterial spin labeling is a subtraction-based MRI technique that can measure CBF globally in the brain without the use of contrast agents, and thus is suitable for repeated measurements over short time periods. Therefore, this work aims to develop and implement a methodological workflow for the acquisition, analysis, absolute quantification, and visualization of longitudinal arterial spin labeling MRI measurements acquired in the clinical NICU setting. At this initial stage, the workflow was implemented and tested using acquired test-retest data and longitudinal data from two healthy participants. Subsequently, the workflow was tested in clinical practice on an intubated and ventilated patient monitored in the NICU after suffering a subarachnoid hemorrhage. To ensure accurate day-to-day comparisons between the repeated measurements, the selection of processing and analysis methods aimed to obtain CBF maps in absolute units of ml/min/100g. These CBF maps were quantified using both the FMRIB Software Library and an openly available flow territory atlas. The test-retest data showed small variations (4.4 ml/min/100g between sessions), and the longitudinal measurement resulted in low CBF variability over 12 days. Despite the greater complexity of clinical data, the quantification and chosen visualization tools proved helpful in interpreting the results. In conclusion, this workflow including repeated MRI measurements could help detect changes in CBF between different measurement days and complement other conventional monitoring techniques in the NICU.

Clinical Characteristics and Outcomes in Patients with Ruptured Middle Cerebral Artery Aneurysms: A Multicenter Study in Northern China

INTRODUCTION

The long-term prognosis of ruptured middle cerebral artery aneurysms (MCAAs) in northern China remains unclear. The aim of this study is to analyze the epidemiological characteristics and long-term outcomes of ruptured MCAAs in northern China.

METHODS

We included patients who were consecutively admitted for ruptured MCAAs to 12 tertiary care centers in northern China from January 2017 to December 2020. Kaplan‒Meier curves were used to compare survival in hazard strata. The Cox proportional hazards model was used to analyze risk factors and mortality risk, whereas logistic regression was used to identify factors influencing 2-year survival. Subgroup analyses were performed to verify the robustness of the results.

RESULTS

Data on 959 patients with ruptured MCAAs were analyzed; 16.4% of these patients had ruptured intracranial aneurysms (RIAs) and were registered in the Chinese cerebral aneurysm database. The mean follow-up duration was 3.0 years (range 0-6.2 years). The 3-month and 2-year mortality rates were 15.5% and 18.2%, respectively. The risk factors for mortality were identified via Cox regression and were as follows: age > 70 years, previous stroke, combined intracerebral hemorrhage (ICH)/intraventricular hemorrhage (IVH), poor Hunt and Hess grade, multiple aneurysms, and conservative treatment (CT). The positive association between the risk of death and CT was consistent across subgroups. According to logistic regression, hypertension, previous stroke, combined ICH/IVH, Hunt and Hess grade, and WFNS (World Federation of Neurological Surgeons) score were identified as factors negatively influencing 2-year survival.

CONCLUSION

We detail the epidemiologic characteristics and long-term outcomes of MCAAs. The risk factors for mortality included age > 70 years, previous stroke, combined ICH/IVH, poor Hunt and Hess grade, and multiple aneurysms. Compared with microsurgical treatment (MST), CT is associated with an increased risk of mortality, while the risk of mortality associated with endovascular treatment (EVT) is not significantly different. Two-year survival was associated with hypertension, previous stroke, ICH/IVH, and poor grades at admission.

Cerebrolysin in Patients Diagnosed with Subarachnoid Hemorrhage-The Results of an Observational Cohort Study

Background: Subarachnoid hemorrhage (SAH) is associated with high mortality and a high level of disability. Progress in surgical and endovascular techniques has lowered the mortality rate in patients with SAH. However, many patients are left with neurological impairment. Objectives: In our study we wanted to examine the impact of Cerebrolysin on treatment results in patients with SAH diagnosis. Methods: The data of 47 patients, divided into Cerebrolysin (26) and non-Cerebrolysin (21) group were included. We examined the correlation between Cerebrolysin administration and additional Amantadine treatment or neuromonitoring, craniectomy, and endovascular treatment and its impact on the Glasgow Outcome Scale (GOS) score, length of stay (LOS), and mortality. Results: Our study shows that Cerebrolysin improves the mortality rate in combination with neuromonitoring in a group of patients with severe SAH. It does not affect the raw values of GOS or LOS in patients with SAH. Conclusions: Further studies with larger patient groups are needed to investigate the role of Cerebrolysin as an additional treatment in SAH.

Role of clipping in aneurysmal subarachnoid hemorrhage: a post hoc analysis of the Earlydrain trial

The choice between clipping and coiling of ruptured cerebral aneurysms in subarachnoid hemorrhage (SAH) remains controversial. The recently published Earlydrain trial provides the opportunity to analyze the latest clip-to-coil ratio in German-speaking countries and to evaluate vasospasm incidence and explorative outcome measures in both treatment modalities. We performed a post hoc analysis of the Earlydrain trial, a multicenter randomized controlled trial investigating the use of an additional lumbar drain in aneurysmal SAH. The decision whether to clip or to coil the ruptured aneurysm was left to the discretion of the participating centers, providing a real-world insight into current aneurysm treatment strategies. Earlydrain was performed in 19 centers in Germany, Switzerland, and Canada, recruiting 287 patients with aneurysmal SAH of all severity grades. Of these, 140 patients (49%) received clipping and 147 patients (51%) coiling. Age and clinical severity based on Hunt-Hess/WFNS grades and radiological criteria were similar. Clipping was more frequently used for anterior circulation aneurysms (55%), whereas posterior circulation aneurysms were mostly coiled (86%, p < 0.001). In high-volume recruiting centers, 56% of patients were treated with clipping, compared to 38% in other centers. A per-year analysis showed a stable and balanced clipping/coiling ratio over time. Regarding vasospasm, 60% of clipped versus 43% of coiled patients showed elevated transcranial Doppler criteria (p = 0.007), reflected in angiographic vasospasm rates (51% vs. 38%, p = 0.03). In contrast to the Earlydrain main results establishing the superiority of an additional lumbar drain, explorative outcomes after clipping and coiling measured by secondary infarctions, mortality, modified Rankin Score, Glasgow Outcome Scale Extended, or Barthel-Index showed no significant differences after discharge and at six months. In clinical practice, aneurysm clipping is still a frequently used method in aneurysmal SAH. Apart from a higher rate of vasospasm in the clipping group, an exploratory outcome analysis showed no difference between the two treatment methods. Further development of periprocedural treatment modalities for clipped ruptured aneurysms to reduce vasospasm is warranted.

Stem Cells Treatment for Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) refers to bleeding in the subarachnoid space, which is a serious neurologic emergency. However, the treatment effects of SAH are limited. In recent years, stem cell (SC) therapy has gradually become a very promising therapeutic method and advanced scientific research area for SAH.

REVIEW SUMMARY

The SCs used for SAH treatment are mainly bone marrow mesenchymal stem cells (BMSCs), umbilical cord mesenchymal stem cells (hUC-MSCs), dental pulp stem cells (DPSCs), neural stem cells (NSCs)/neural progenitor cell (NPC), and endothelial progenitor cell (EPC). The mechanisms mainly included differentiation and migration of SCs for tissue repair; alleviating neuronal apoptosis; anti-inflammatory effects; and blood-brain barrier (BBB) protection. The dosage of SCs was generally 106 orders of magnitude. The administration methods included intravenous injection, nasal, occipital foramen magnum, and intraventricular administration. The administration time is generally 1 hour after SAH modeling, but it may be as late as 24 hours or 6 days. Existing studies have confirmed the neuroprotective effect of SCs in the treatment of SAH.

CONCLUSIONS

SC has great potential application value in SAH treatment, a few case reports have provided support for this. However, the relevant research is still insufficient and there is still a lack of clinical research on the SC treatment for SAH to further evaluate the effectiveness and safety before it can go from experiment to clinical application.

Association between estimated pulse wave velocity and the risk of mortality in patients with subarachnoid hemorrhage: a retrospective cohort study based on the MIMIC database

BACKGROUND

The estimated pulse wave velocity (ePWV) is a recently developed, simple and useful tool to measure arterial stiffness and to predict long-term cardiovascular mortality. However, the association of ePWV with mortality risk in patients with subarachnoid hemorrhage (SAH) is unclear. Herein, this study aims to assess the potential prediction value of ePWV on short- and long-term mortality of SAH patients.

METHODS

Data of adult patients with no traumatic SAH were extracted from the Medical Information Mart for Intensive Care (MIMIC) III and IV database in this retrospective cohort study. Weighted univariate and multivariable Cox regression analyses were used to explore the associations of ePWV levels with 30-day mortality and 1-year mortality in SAH patients. The evaluation indexes were hazard ratios (HRs) and 95% confidence intervals (CIs). In addition, subgroup analyses of age, the sequential organ failure assessment (SOFA) score, surgery, atrial fibrillation (AF), renal failure (RF), hepatic diseases, chronic obstructive pulmonary disease (COPD), sepsis, hypertension, and diabetes mellitus (DM) were also performed.

RESULTS

Among 1,481 eligible patients, 339 died within 30 days and 435 died within 1 year. After adjusting for covariates, ePWV ≥ 12.10 was associated with higher risk of both 30-day mortality (HR = 1.77, 95%CI: 1.17-2.67) and 1-year mortality (HR = 1.97, 95%CI: 1.36-2.85), compared to ePWV < 10.12. The receiver operator characteristic (ROC) curves showed that compared to single SOFA score, ePWV combined with SOFA score had a relative superior predictive performance on both 30-day mortality and 1-year mortality, with the area under the curves (AUCs) of 0.740 vs. 0.664 and 0.754 vs. 0.658. This positive relationship between ePWV and mortality risk was also found in age ≥ 65 years old, SOFA score < 2, non-surgery, non-hepatic diseases, non-COPD, non-hypertension, non-DM, and sepsis subgroups.

CONCLUSION

Baseline ePWV level may have potential prediction value on short- and long-term mortality in SAH patients. However, the application of ePWV in SAH prognosis needs further clarification.

Risk Factors for the Development of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a common neurosurgical disorder with high morbidity and poor prognosis, and the associated delayed cerebral ischemia (DCI) is a key factor contributing to poor prognosis. Despite extensive research on the risk factors associated with DCI development, the evidence remains conflicting. Therefore, this meta-analysis of case-control studies aimed to investigate the risk factors for DCI occurrence during hospitalization in patients with aSAH.

METHODS

We systematically searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials for eligible studies published before November 20, 2023. Two independent reviewers extracted relevant data from the included studies using a pre-established data extraction form. The primary outcome was DCI occurrence during hospitalization in patients with aSAH.

RESULTS

A total of 42 studies involving 21,726 patients with aSAH were included. The pooled meta-analysis showed that female sex; Hunt-Hess, modified Fisher, and World Federation of Neurosurgical Societies scale scores of 4-5, 3-4, and 4-5, respectively; vasospasm; combined intraventricular hemorrhage; pre-existing hypertension; hydrocephalus; intracranial infections; and high white blood cell count on admission were independent risk factors for the development of postoperative DCIs in patients with aSAH.

CONCLUSIONS

Patients with aSAH who have a Hunt-Hess scale score ≥4, a modified Fisher scale score ≥3, a WFNS scale score ≥4, intraventricular hemorrhage, pre-existing hypertension, cerebral vasospasm, a high white blood cell count on admission, intracranial infection, and female sex are at high risk of DCI and hence should be carefully monitored in the intensive care unit.

High levels of blood lipid and glucose predict adverse prognosis in patients with aneurysmal subarachnoid hemorrhage

Objective

We conducted a retrospective study on the prognostic factors of aneurysmal subarachnoid hemorrhage (aSAH) patients in the author's Hospital from January 2019 to May 2023. To discuss the association of the blood lipid and glucose levels of patients with the prognosis of aSAH, and verify that high blood lipid and glucose levels are important factors affecting adverse prognosis.

Methods

All patients with aSAH were collected as the case group, which was divided into two groups according to the modified Rankin Scores (mRS), the good prognosis group (Group A, mRS ＜ 3) and the adverse prognosis group (Group B,mRS ≥3). The clinical data of age, gender, accompanied chronic diseases (hypertension, diabetes), smoking, drinking, Glasgow Coma Scale (GCS), Hunt-Hess (H-H) grade, Modified Fisher grade, total cholesterol (TC) , triglyceride (TG) , high-density cholesterol lipoprotein (HDL-C) , low-density cholesterol lipoprotein (LDL-C) , blood glucose (BG) , responsible aneurysm diameter and location were recorded too. Correlations between blood lipid and glucose levels and Modified Fisher grade were assessed by the Spearman correlation analysis. The receiver operating characteristic (ROC) curve was utilized to evaluate the diagnostic efficacy. The effect of blood lipid and glucose levels on adverse prognosis was analyzed by Logistic regression models.

Result

A total of 259 patients with aSAH were enrolled. The average age of all patients is (56.54 ± 10.52) years, including 96 males and 163 females. They were divided into Group A (n = 146) and Group B (n = 113). Univariate analysis results show that age, the levels of TC, TG, LDL-C, and BG were higher in Group B (P < 0.05). Besides, Group B had more severe GCS, H-H grade, and Modified Fisher grade than Group A, and a higher proportion of intracranial aneurysms with larger diameter (P < 0.05). Correlation analysis showed that TC, TG, LDL-C, and BG levels were positively correlated with Modified Fisher grade (P < 0.05) and H-H grade (P < 0.05). Multivariate logistic regression model analysis showed that high level of Modified Fisher grade (OR = 0.079, 95%CI: 0.027-0.230) , high level of H-H grade (OR = 0.204, 95%CI: 0.067-0.622) , TC (OR = 10.711, 95%CI: 2.457-46.700) , LDL-C (OR = 0.178, 95%CI: 0.039-0.823) and BG (OR = 1.273, 95%CI: 1.012-1.602) increased the risk of adverse prognosis. The AUC of "H-H grade", "Modified Fisher grade", "TC level", "LDL-C level" and "BG level" was 0.822, 0.885, 0.860, 0.772, and 0.721, respectively, in the ROC curve.

Conclusion

Modified Fisher grade, H-H grade, TC, LDL-C, and BG levels at admission were independent predictors of adverse prognosis of aSAH. Besides, TC, LDL-C, and BG levels were positively correlated with Modified Fisher grade and Hunt-Hess grade. What's more, high levels of TC, LDL-C, and BG combined with Modified Fisher grade and H-H grade can identify high-risk groups with adverse prognoses in aSAH patients.

Transcription factor EB (TFEB) promotes autophagy in early brain injury after subarachnoid hemorrhage in rats

Subarachnoid hemorrhage (SAH) has high mortality. Early brain injury (EBI) is responsible for unfavorable outcomes for patients with SAH. The protective involvement of autophagy in hemorrhagic stroke has been proposed. The transcription factor EB (TFEB) can increase autophagic flux by promoting autophagosome formation and autophagosome-lysosome fusion, and dysregulation of TFEB activity might induce the development of several diseases. However, the biological functions of TFEB in EBI after SAH remain unknown. We established an animal model of SAH by the modified endovascular perforation method. Expression of TFEB and autophagy required genes was measured by western blotting and immunofluorescence staining. SAH grading, brain water content and neurobehavioral functions were evaluated at 24 h post-SAH. Neuronal apoptosis in cerebral cortex was assessed by TUNEL staining and Fluoro Jade B staining. TFEB was downregulated in SAH rats, and its overexpression reduced brain edema and ameliorated neurological deficits of SAH rats. Additionally, the neuronal apoptosis induced by SAH was inhibited by TFEB overexpression. Moreover, TFEB overexpression promoted autophagy after SAH. TFEB overexpression promotes autophagy to inhibit neuronal apoptosis, brain edema and neurological deficits post-SAH.

Promise of mesenchymal stem cell-derived extracellular vesicles for alleviating subarachnoid hemorrhage-induced brain dysfunction by neuroprotective and antiinflammatory effects

Subarachnoid hemorrhage (SAH), accounting for ∼5% of all strokes, represents a catastrophic subtype of cerebrovascular accident. SAH predominantly results from intracranial aneurysm ruptures and affects ∼30,000 individuals annually in the United States and ∼6 individuals per 100,000 people worldwide. Recent studies have implicated that administering mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) may be beneficial in inducing neuroprotective and antiinflammatory effects following SAH. EVs are nanosized particles bound by a lipid bilayer. MSC-EVs comprise a therapeutic cargo of nucleic acids, lipids, and proteins, having the promise to ease SAH-induced long-term brain impairments. This review evaluated the findings of published studies on the therapeutic efficacy of MSC-EVs in the context of SAH. A growing body of evidence points out the therapeutic potential of MSC-EVs for improving brain function in animal models of SAH. Specifically, studies demonstrated their ability to reduce neuronal apoptosis and neuroinflammation and enhance neurological recovery through neuroprotective and antiinflammatory mechanisms. Such outcomes reported in various studies suggest that MSC-EVs hold great potential as a novel and minimally invasive approach to ameliorate SAH-induced neurological damage and improve patient outcomes. The review also discusses the limitations of EV therapy and the required future research efforts toward harnessing the full potential of MSC-EVs in treating SAH.

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.

Usefulness of plasma glucose to potassium ratio in predicting the short-term mortality of patients with aneurysmal subarachnoid hemorrhage

Rationale and objectives

To investigate the relationship between the glucose/potassium ratio (GPR) at admission and 30-day mortality in patients diagnosed with aneurysmal subarachnoid hemorrhage (SAH) in the emergency department (ED).

Materials and methods

Patients with a modified Rankin Scale (mRS) score of ≤2 before SAH and patients aged 18 years or older were included in the study. The patients were divided into two groups based on their functional outcomes (poor-good) and 30-day mortality rates (survivor and non-survivor) and their clinical and laboratory values were compared.

Results

The study included 134 patients with a mean age of 65.9 ± 16.7 years, of whom 68 (50.7 %) were female. The mean glucose and GPR levels in the poor functional outcome group were significantly higher than those in the good functional outcome group (p = 0.003, p = 0.03, respectively). The mean glucose and GPR levels in the non-survivor group were significantly higher than those in the survivor group (p = 0.004, p = 0.023, respectively). Multivariate logistic regression analysis identified GPR as an independent predictor of 30-day mortality (p = 0.043, OR: 4.041, 95 % CI: 1.45-26.147), alongside the Rankin Scale score (p = 0.002, OR: 12.714, 95 % CI: 2.578-62.706). Other variables, including age, Hunt-Hess score, and Glasgow Coma Scale, were not statistically significant.

Conclusion

The findings indicate that the GPR is a significant independent predictor of short-term mortality in patients with aneurysmal subarachnoid hemorrhage. The translation of these findings into clinical practice may help achieve better outcomes in the management of SAH patients.

The urotensin II receptor triggers an early meningeal response and a delayed macrophage-dependent vasospasm after subarachnoid hemorrhage in male mice

Subarachnoid hemorrhage (SAH) can be associated with neurological deficits and has profound consequences for mortality and morbidity. Cerebral vasospasm (CVS) and delayed cerebral ischemia affect neurological outcomes in SAH patients, but their mechanisms are not fully understood, and effective treatments are limited. Here, we report that urotensin II receptor UT plays a pivotal role in both early events and delayed mechanisms following SAH in male mice. Few days post-SAH, UT expression is triggered by blood or hemoglobin in the leptomeningeal compartment. UT contributes to perimeningeal glia limitans astrocyte reactivity, microvascular alterations and neuroinflammation independent of CNS-associated macrophages (CAMs). Later, CAM-dependent vascular inflammation and subsequent CVS develop, leading to cognitive dysfunction. In an SAH model using humanized UTh+/h+ male mice, we show that post-SAH CVS and behavioral deficits, mediated by UT through Gq/PLC/Ca2+ signaling, are prevented by UT antagonists. These results highlight the potential of targeting UT pathways to reduce early meningeal response and delayed cerebral ischemia in SAH patients.

Cerebrospinal fluid markers of neuroinflammation and coagulation in severe cerebral edema and chronic hydrocephalus after subarachnoid hemorrhage: a prospective study

BACKGROUND

Early severe cerebral edema and chronic hydrocephalus are the primary cause of poor prognosis in patients with subarachnoid hemorrhage (SAH). This study investigated the role of cerebrospinal fluid (CSF) inflammatory cytokines and coagulation factors in the development of severe cerebral edema and chronic hydrocephalus in patients with SAH.

METHODS

Patients with SAH enrolled in this study were categorized into mild and severe cerebral edema groups based on the Subarachnoid Hemorrhage Early Brain Edema Score at admission. During long-term follow-up, patients were further classified into hydrocephalus and non-hydrocephalus groups. CSF samples were collected within 48 h post-SAH, and levels of inflammatory cytokines and coagulation factors were measured. Univariate and multivariate logistic regression analyses were performed to identify independent factors associated with severe cerebral edema and chronic hydrocephalus. The correlation between inflammatory cytokines and coagulation factors was further investigated and validated in a mouse model of SAH.

RESULTS

Seventy-two patients were enrolled in the study. Factors from the extrinsic coagulation pathway and inflammatory cytokines were associated with both severe cerebral edema and chronic hydrocephalus. Coagulation products thrombin-antithrombin complexes (TAT) and fibrin, as well as inflammatory cytokines IL-1β, IL-2, IL-5, IL-7, and IL-4, were independently associated with severe cerebral edema. Additionally, Factor VII, fibrin, IL-2, IL-5, IL-12, TNF-α, and CCL-4 were independently associated with chronic hydrocephalus. A positive correlation between extrinsic coagulation factors and inflammatory cytokines was observed. In the SAH mouse model, tissue plasminogen activator was shown to alleviate neuroinflammation and cerebral edema, potentially by restoring glymphatic-meningeal lymphatic function.

CONCLUSIONS

Elevated levels of inflammatory cytokines and extrinsic coagulation pathway factors in the CSF are associated with the development of early severe cerebral edema and chronic hydrocephalus following SAH. These factors are interrelated and may contribute to post-SAH glymphatic-meningeal lymphatic dysfunction.

Propofol alleviates M1 polarization and neuroinflammation of microglia in a subarachnoid hemorrhage model in vitro, by targeting the miR-140-5p/TREM-1/NF-κB signaling axis

Subarachnoid hemorrhage (SAH) is a devastating stroke caused by ruptured intracranial aneurysms, leading to blood accumulation around the brain. Early brain injury (EBI) within 72 h post-SAH worsens prognosis, primarily due to intense neuroinflammation. Microglia, pivotal in central nervous system defense and repair, undergo M1 to M2 polarization post-SAH, with M1 exacerbating neuroinflammation. Propofol (PPF), an anesthetic with anti-inflammatory properties, shows promise in mitigating neuroinflammation in SAH by modulating microglial activation. It likely acts through microRNAs like miR-140-5p, which attenuates microglial activation and inflammation by targeting TREM-1 and the NF-κB pathway. Understanding these mechanisms could lead to new therapeutic approaches for SAH-related EBI. In this study, BV-2 cell was used to establish in vitro model of SAH, and the expression of miR-140-5p and TREM-1 was detected after modeling. Microglial activity, apoptosis, the inflammatory pathway and response, oxidative damage, and M1/M2 polarization of microglia were evaluated by drug administration or transfection according to experimental groups. Finally, the targeting relationship between miR-140-5p and TREM-1 was verified by dual luciferase reporter assays, and the effect of PPF on the miR-140-5p/TREM-1/NF-κB signaling cascade was evaluated by RT‒qPCR or Western blotting. PPF effectively mitigates apoptosis, neuroinflammation, oxidative damage, and M1 microglial polarization in SAH. In SAH cells, PPF upregulates miR-140-5p and downregulates TREM-1. Mechanistically, PPF boosts miR-140-5p expression, while TREM-1, a downstream target of miR-140-5p, inhibits NF-κB signaling by regulating TREM-1, promoting M1 to M2 microglial polarization. Reduced miR-140-5p or increased TREM-1 counters PPF's therapeutic impact on SAH cells. In conclusion, PPF plays a neuroprotective role in SAH by regulating the miR-140-5p/TREM-1/NF-κB signaling axis to inhibit neuroinflammation and M1 polarization of microglia.

miR-19-3p/GRSF1/COX1 axis attenuates early brain injury via maintaining mitochondrial function after subarachnoid haemorrhage

BACKGROUND

Guanine-rich RNA sequence binding factor 1 (GRSF1) is an RNA-binding protein, which is eventually localised to mitochondria and promotes the translation of cytochrome C oxidase 1 (COX1) mRNA. However, the role of the miR-19-3p/GRSF1/COX1 axis has not been investigated in an experimental subarachnoid haemorrhage (SAH) model. Thus, we investigated the role of the miR-19-3p/GRSF1/COX1 axis in a SAH-induced early brain injury (EBI) course.

METHODS

Primary neurons were treated with oxyhaemoglobin (OxyHb) to simulate in vitro SAH. The rat SAH model was established by injecting autologous arterial blood into the optic chiasma cisterna. The GRSF1 level was downregulated or upregulated by treating the rats and neurons with lentivirus-GRSF1 shRNA (Lenti-GRSF1 shRNA) or lentivirus-GRSF1 (Lenti-GRSF1).

RESULTS

The miR-19-3p level was upregulated and the protein levels of GRSF1 and COX1 were both downregulated in SAH brain tissue. GRSF1 silence decreased and GRSF1 overexpression increased the protein levels of GRSF1 and COX1 in primary neurons and brain tissue, respectively. Lenti-GRSF1 shRNA aggravated, but Lenti-GRSF1 alleviated, the indicators of neuronal injury and neurological impairment in both in vitro and in vivo SAH conditions. In addition, miR-19-3p mimic reduced the protein levels of GRSF1 and COX1 in cultured neurons while miR-19-3p inhibitor increased them. More importantly, Lenti-GRSF1 significantly relieved mitochondrial damage of neurons exposed to OxyHb or induced by SAH and was beneficial to maintaining mitochondrial integrity. Lenti-GRSF1 shRNA treatment, conversely, aggravated mitochondrial damage in neurons.

CONCLUSION

The miR-19-3p/GRSF1/COX1 axis may serve as an underlying target for inhibiting SAH-induced EBI by maintaining mitochondrial integrity.

TREM2 alleviates long-term cognitive dysfunction after subarachnoid hemorrhage in mice by attenuating hippocampal neuroinflammation via PI3K/Akt signaling pathway

Subarachnoid hemorrhage (SAH) often leads to long-term cognitive deficits in patients, particularly due to injury to brain regions such as the hippocampus. This study aims to investigate the role of the triggering receptor expressed on myeloid cells 2 (TREM2) in mitigating hippocampal injury and associated cognitive impairments following SAH. To explore the protective effects of TREM2, we utilized the TREM2 agonist COG1410 to upregulate TREM2 expression and employed TREM2 knockout (KO) mice to verify the necessity of TREM2 for this protective role. The study further examined the involvement of the PI3K/Akt signaling pathway in TREM2-mediated neuroprotection. Our findings indicate that the upregulation of TREM2 significantly alleviated long-term cognitive deficits and promoted the recovery of hippocampal neural activity post-SAH. The neuroprotective effects were linked to reduced microglial activation and decreased secretion of inflammatory factors within the hippocampus. In contrast, TREM2 KO mice did not exhibit these protective effects. Furthermore, inhibition of the PI3K/Akt pathway also diminished these protective effects of TREM2 upregulation and worsened cognitive outcomes. In conclusion, TREM2 upregulation mitigates long-term cognitive dysfunction following SAH by attenuating hippocampal neuroinflammation via the PI3K/Akt signaling pathway. These findings suggest that TREM2 could be a potential therapeutic target for improving cognitive outcomes after SAH.

Integrating Clinical Data and Radiomics and Deep Learning Features for End-to-End Delayed Cerebral Ischemia Prediction on Noncontrast CT

BACKGROUND AND PURPOSE

Delayed cerebral ischemia is hard to diagnose early due to gradual, symptomless development. This study aimed to develop an automated model for predicting delayed cerebral ischemia following aneurysmal SAH on NCCT.

MATERIALS AND METHODS

This retrospective study included 400 patients with aneurysmal SAH (156 with delayed cerebral ischemia) who underwent NCCT. The study used ATT-Deeplabv3+ for automatically segmenting hemorrhagic regions using semisupervised learning. Principal component analysis was used for reducing the dimensionality of deep learning features extracted from the average pooling layer of ATT-DeepLabv3+. The classification model integrated clinical data, radiomics, and deep learning features to predict delayed cerebral ischemia. Feature selection involved Pearson correlation coefficients, least absolute shrinkage, and selection operator regression. We developed models based on clinical features, clinical-radiomics, and a combination of clinical, radiomics, and deep learning. The study selected logistic regression, Naive Bayes, Adaptive Boosting (AdaBoost), and multilayer perceptron as classifiers. The performance of segmentation and classification models was evaluated on their testing sets using the Dice similarity coefficient for segmentation, and the area under the receiver operating characteristic curve (AUC) and calibration curves for classification.

RESULTS

The segmentation process achieved a Dice similarity coefficient of 0.91 and the average time of 0.037 s/image. Seventeen features were selected to calculate the radiomics score. The clinical-radiomics-deep learning model with multilayer perceptron achieved the highest AUC of 0.84 (95% CI, 0.72-0.97), which outperformed the clinical-radiomics model (P = .002) and the clinical features model (P = .001) with multilayer perceptron. The performance of clinical-radiomics-deep learning model using AdaBoost was significantly superior to its clinical-radiomics model (P = .027). The performance of the clinical-radiomics-deep learning model and the clinical-radiomics model with logistic regression notably exceeded that of the model based solely on clinical features (P = .028; P = .046). The AUC of the clinical-radiomics-deep learning model with multilayer perceptron (P < .001) and the clinical-radiomics model with logistic regression (P = .046) were significantly higher than the clinical model with logistic regression. Of all models, the clinical-radiomics-deep learning model with multilayer perceptron showed best calibration.

CONCLUSIONS

The proposed 2-stage end-to-end model not only achieves rapid and accurate segmentation but also demonstrates superior diagnostic performance with high AUC values and good calibration in the clinical-radiomics-deep learning model, suggesting its potential to enhance delayed cerebral ischemia detection and treatment strategies.

Perfusion imaging for delayed cerebral ischemia detection in patients following ruptured aneurysmal subarachnoid hemorrhage: Interrater reliability assessment

BACKGROUND

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) is associated with adverse neurological outcomes. Early and accurate diagnosis of DCI is crucial to prevent cerebral infarction. This study aimed to assess the diagnostic accuracy and interrater agreement of the visual assessment of neuroimaging perfusion maps to detect DCI in patients suspected of vasospasm after aSAH.

METHODS

In this case-control study, cases were adult aSAH patients with DCI who underwent magnetic resonance perfusion or computed tomography perfusion (CTP) imaging in the 24 h prior to digital subtraction angiography for vasospasm diagnosis. Controls were patients with dizziness and no aSAH on CTP imaging. Three independent raters, blinded to patients' clinical information, other neuroimaging studies, and angiographic results, visually assessed anonymized perfusion color maps to classify patients as either having DCI or not. Tmax delay was classified by symmetry into no delay, unilateral, or bilateral.

RESULTS

Perfusion imaging of 54 patients with aSAH and 119 control patients without aSAH was assessed. Sensitivities for DCI diagnosis ranged from 0.65 to 0.78, and specificities ranged from 0.70 to 0.87, with interrater agreement ranging from 0.60 (moderate) to 0.68 (substantial).

CONCLUSION

Visual assessment of perfusion color maps demonstrated moderate to substantial accuracy in diagnosing DCI in aSAH patients.

Betulin ameliorates neuronal apoptosis and oxidative injury via DJ-1/Akt/Nrf2 signaling pathway after subarachnoid hemorrhage

AIMS

We aimed to resolve the uncertainty as to whether betulin exerted neuroprotection on early brain injury (EBI) caused by subarachnoid hemorrhage (SAH), and to investigate the related molecular mechanisms.

METHODS

Bioinformatic analysis was performed to pre-study the differently expressed genes (DEGs) and the possible signaling pathways. Rat and cellular model of SAH were introduced in this study, and betulin, an activator of DJ-1 protein, was administered to reveal the effect. Gross assessment regarding mortality, neurofunctions, SAH grade, brain water content (BWC) along with multiple cellular and molecular studies in vivo or/and in vitro such as immunofluorescence (IF) staining, western blot (WB), reactive oxygen species (ROS) assay, and flow cytometry (FCM) were all conducted after SAH induction to verify the protective effect and the relevant mechanisms of DJ-1 in diverse levels. In addition, MK2206 (selective inhibitor of Akt) and iRNADj-1 (interfering RNA to Dj-1) were utilized to confirm the mechanisms of the effect.

RESULTS

The data from our study showed that DJ-1 protein was moderately expressed in neurons, microglia, and astrocytes; its level in brain tissue elevated and peaked at 24-72 h after SAH induction. Betulin could efficaciously induce the expression of DJ-1 which in turn activated Akt and Bcl-2, and anti-oxidative enzymes SOD2 and HO-1, functioning to reduce the activation of cleaved caspase-3 (c-Casp-3) and reactive oxygen species (ROS). The induced DJ-1 could upregulate the expression of Nrf2. However, Akt seemed no direct effect on elevating the expression of Nrf2. DJ-1 alone could as well activate Akt-independent antiapoptotic pathway via suppressing the activation of caspase-8 (Casp-8).

CONCLUSIONS

Betulin which was a potent agonist of DJ-1 had the ability to induce its expression in brain tissue. DJ-1 had neuroprotective effect on EBI through comprehensive mechanisms, including facilitating intrinsic and extrinsic antiapoptotic pathway, and reducing oxidative injury by upregulating the expression of redox proteins. Betulin as an inexpensive drug showed the potential for SAH treatment.

Clearance of erythrocytes from the subarachnoid space through cribriform plate lymphatics in female mice

BACKGROUND

Atraumatic subarachnoid haemorrhage (SAH) is associated with high morbidity and mortality. Proposed mechanisms for red blood cell (RBC) clearance from the subarachnoid space (SAS) are erythrolysis, erythrophagocytosis or through efflux along cerebrospinal fluid (CSF) drainage routes. We aimed to elucidate the mechanisms of RBC clearance from the SAS to identify targetable efflux pathways.

METHODS

Autologous fluorescently-labelled RBCs along with PEGylated 40 kDa near-infrared tracer (P40D800) were infused via the cisterna magna (i.c.m.) in female reporter mice for lymphatics or for resident phagocytes. Drainage pathways for RBCs to extracranial lymphatics were evaluated by in vivo and in situ near-infrared imaging and by immunofluorescent staining on decalcified cranial tissue or dural whole-mounts.

FINDINGS

RBCs drained to the deep cervical lymph nodes 15 min post i.c.m. infusion, showing similar dynamics as P40D800 tracer. Postmortem in situ imaging and histology showed perineural accumulations of RBCs around the optic and olfactory nerves. Numerous RBCs cleared through the lymphatics of the cribriform plate, whilst histology showed no relevant fast RBC clearance through dorsal dural lymphatics or by tissue-resident macrophage-mediated phagocytosis.

INTERPRETATION

This study provides evidence for rapid RBC drainage through the cribriform plate lymphatic vessels, whilst neither fast RBC clearance through dorsal dural lymphatics nor through spinal CSF efflux or phagocytosis was observed. Similar dynamics of P40D800 and RBCs imply open pathways for clearance that do not impose a barrier for RBCs. This finding suggests further evaluation of the cribriform plate lymphatic function and potential pharmacological targeting in models of SAH.

FUNDING

Swiss National Science Foundation (310030_189226), SwissHeart (FF191155).

Microglia aggravate white matter injury via C3/C3aR pathway after experimental subarachnoid hemorrhage

The activation of glial cells is intimately associated with the pathophysiology of neuroinflammation and white matter injury (WMI) during both acute and chronic phases following subarachnoid hemorrhage (SAH). The complement C3a receptor (C3aR) has a dual role in modulating inflammation and contributes to neurodevelopment, neuroplasticity, and neurodegeneration. However, its impact on WMI in the context of SAH remains unclear. In this study, 175 male C57BL/6J mice underwent SAH through endovascular perforation. Oxyhemoglobin (oxy-Hb) was employed to simulate SAH in vitro. A suite of techniques, including immunohistochemistry, transcriptomic sequencing, and a range of molecular biotechnologies, were utilized to evaluate the activation of the C3-C3aR pathway on microglial polarization and WMI. Results revealed that post-SAH abnormal activation of microglia was accompanied by upregulation of complement C3 and C3aR. The inhibition of C3aR decreased abnormal microglial activation, attenuated neuroinflammation, and ameliorated WMI and cognitive deficits following SAH. RNA-Seq indicated that C3aR inhibition downregulated several immune and inflammatory pathways and mitigated cellular injury by reducing p53-induced death domain protein 1 (Pidd1) and Protein kinase RNA-like ER kinase (Perk) expression, two factors mainly function in sensing and responding to cellular stress and endoplasmic reticulum (ER) stress. The deleterious effects of the C3-C3aR axis in the context of SAH may be related to endoplasmic reticulum (ER) stress-dependent cellular injury and inflammasome formation. Agonists of Perk can exacerbate the cellular injury and neuroinflammation, which was attenuated by C3aR inhibition after SAH. Additionally, intranasal administration of C3a during the subacute phase of SAH was found to decrease astrocyte reactivity and alleviate cognitive deficits post-SAH. This research deepens our understanding of the complex pathophysiology of WMI following SAH and underscores the therapeutic potential of C3a treatment in promoting white matter repair and enhancing functional recovery prognosis. These insights pave the way for future clinical application of C3a-based therapies, promising significant benefits in the treatment of SAH and its related complications.

A nomogram model for predicting postoperative prognosis in patients with aneurysmal subarachnoid hemorrhage using preoperative biochemical indices

OBJECTIVE

The nutritional status and inflammatory responses of patients with aneurysmal subarachnoid hemorrhage (aSAH) play a vital prognostic role. We investigated the relationship between preoperative prognostic nutritional index (PNI)、neutrophil/albumin ratio (NAR)、platelet/albumin ratio (PAR) and other factors and the clinical prognosis of patients who underwent clipping for aSAH and its predictive model.

METHODS

The clinical data of 212 patients with aSAH who underwent neurosurgery at Nanyang Central Hospital between 2018 and 2023 were retrospectively analyzed. Based on the Glasgow Outcome Scale (GOS) score at 6 months postoperatively, the patients were categorized into two groups: poor (GOSI-III) and good (GOSIV-V) prognosis groups. Multivariate logistic regression analysis was performed to determine the predictive value of preoperative PNI、NAR、PAR、hyperlipidemia and Glasgow Coma Scale (GCS) for prognosis. Furthermore, nomograms and prognostic prediction models were constructed. Receiver operating characteristic curves and area under the curve (AUC) were utilized to determine the predictive values.

RESULTS

Multivariate logistic regression analysis revealed that PNI (OR = 1.250, 95%CI 1.060 ~ 1.475, P = 0.008), NAR (OR = 0.000, 95%CI 0.000 ~ 0.004, P = 0.000), PAR(OR = 0.515, 95%CI 0.283 ~ 0.937, P = 0.030), hyperlipidemia (OR = 4.627, 95%CI 1.166 ~ 18.367, P = 0.029), and GCS(OR = 1.446, 95%CI 1.041 ~ 2.008, P = 0.028) are independent risk factors for poor postoperative prognosis. The total score of the nomogram was 200, and the AUC value was 0.972.

CONCLUSIONS

PNI and NAR can reflect the nutritional status and inflammatory responses of patients.They are significantly associated with the postoperative prognosis of patients with aSAH. Comprehensively analyzing PNI and NAR combined with other clinical indicators can more effectively guide treatment and help predict prognosis.

D-Dimer and the Short-Term Prognosis of Patients with Subarachnoid Hemorrhage: A Meta-Analysis

INTRODUCTION

Elevated plasma D-dimer has been observed in acute phase of subarachnoid hemorrhage (SAH), while a quantitative evaluation for the association between D-dimer level and prognosis of SAH remains lacking. The aim of the meta-analysis was to investigate the potential predictive role of D-dimer for the short-term functional outcome of patients with SAH.

METHODS

Relevant observational studies were retrieved by searching PubMed, Web of Science, Embase, Wanfang, and CNKI. A poor functional outcome was generally defined by the Glasgow Outcome Scale (1-3) or the modified Rankin Scale (≥3). A random-effects model was used to combine the data by incorporating the influence of between-study heterogeneity.

RESULTS

Eleven studies involving 3,748 patients with SAH were included. Among them, 1,131 patients (30.2%) developed a poor functional outcome within 6 months. The pooled results showed that a higher plasma D-dimer at admission was associated with a higher risk of poor functional outcome during follow-up (odds ratio per 1 mg/L increment of D-dimer: 1.65, 95% confidence interval: 1.49-1.82, p < 0.001; I2 = 0%). Sensitivity analysis by excluding one study at a time showed similar results. Subgroup analyses suggested that the association between D-dimer and poor functional outcome of patients with SAH was not significantly affected by study design, country, mean age, proportion of men, follow-up duration, methods for defining poor outcome, study quality scores, timing of D-dimer measurement, or the publication year.

CONCLUSION

A high plasma D-dimer at admission is associated with a poor short-term functional outcome of patients with SAH.

The factors associated with the modified Fisher grade in patients with aneurysmal subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening medical condition with a high fatality and morbidity rate. There was a substantial link between the modified Fisher grade of aSAH and the neurological function deficit. This study aimed to analyze the factors associated with the modified Fisher grade of aSAH using a machine learning approach.

Methods

A multi-center observational study was conducted. The patients with aSAH were recruited from five tertiary hospitals in China. The volume of hemorrhage in aSAH was measured using the modified Fisher grade scale. The risk factors responsible for the modified Fisher grade of aSAH were analyzed, which include sociodemographic factors, clinical factors, blood index, and ruptured aneurysm characteristics. We built several tree-based machine learning models (XGBoost, CatBoost, LightGBM) for prediction and used grid search to optimize model parameters. To comprehensively evaluate the model, we used Accuracy, Precision, Area Under the Receiver Operating Characteristic Curve (AUROC), Area Under the Precision-Recall Curve (AUPRC), and Brier as evaluation indicators to assess the model performance and select the best model.

Results

A total of 888 patients with aSAH were recruited, of whom 305 with modified Fisher grade of 3 and 4. The results show that the XGBoost model has the highest AUROC of 0.772, and the indicators are better than CatBoost and LightGBM. The feature importance graph shows that the top feature variables include platelet, thrombin time, fibrinogen, preadmission systolic blood pressure, activated partial thromboplastin time, and the time interval between the onset of aSAH and the first-time CT examination.

Conclusion

The factors responsible for the modified Fisher grade of aSAH were identified, which offered valuable insights for future research and clinical intervention. These risk factors should be controlled in the treatment of unruptured aneurysms, and appropriate treatment can be given if necessary to reduce the risk of severe hemorrhage after aneurysm rupture.

Predictors of Intrahospital Mortality in Aneurysmal Subarachnoid Hemorrhage after Endovascular Embolization

Background and Objectives: Aneurysmal subarachnoid hemorrhage (ASAH) is defined as bleeding in the subarachnoid space caused by the rupture of a cerebral aneurysm. About 11% of people who develop ASAH die before receiving medical treatment, and 40% of patients die within four weeks of being admitted to hospital. There are limited data on single-center experiences analyzing intrahospital mortality in ASAH patients treated with an endovascular approach. Given that, we wanted to share our experience and explore the risk factors that influence intrahospital mortality in patients with ruptured intracranial aneurysms treated with endovascular coil embolization. Materials and Methods: Our study was designed as a clinical, observational, retrospective cross-sectional study. It was performed at the Department for Radiology, University Clinical Center Kragujevac in Kragujevac, Serbia. The study inclusion criteria were ≥18 years, admitted within 24 h of symptoms onset, acute SAH diagnosed on CT, aneurysm on DSA, and treated by endovascular coil embolization from January 2014 to December 2018 at our institution. Results: A total of 66 patients were included in the study-48 (72.7%) women and 18 (27.3%) men, and 19.7% of the patients died during hospitalization. After adjustment, the following factors were associated with in-hospital mortality: a delayed ischemic neurological deficit, the presence of blood in the fourth cerebral ventricle, and an elevated urea value after endovascular intervention, increasing the chances of mortality by 16.3, 12, and 12.6 times. Conclusions: Delayed cerebral ischemia and intraventricular hemorrhage on initial head CT scan are strong predictors of intrahospital mortality in ASAH patients. Also, it is important to monitor kidney function and urea levels in ASAH patients, considering that elevated urea values after endovascular aneurysm embolization have been shown to be a significant risk factor for intrahospital mortality.

Epidemiological trends of subarachnoid hemorrhage at global, regional, and national level: a trend analysis study from 1990 to 2021

BACKGROUND

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke characterized by high mortality and low rates of full recovery. This study aimed to investigate the epidemiological characteristics of SAH between 1990 and 2021.

METHODS

Data on SAH incidence, mortality, and disability-adjusted life-years (DALYs) from 1990 to 2021 were obtained from the Global Burden of Disease Study (GBD) 2021. Estimated annual percentage changes (EAPCs) were calculated to evaluate changes in the age-standardized rate (ASR) of incidence and mortality, as well as trends in SAH burden. The relationship between disease burden and sociodemographic index (SDI) was also analyzed.

RESULTS

In 2021, the incidence of SAH was found to be 37.09% higher than that in 1990; however, the age-standardized incidence rates (ASIRs) showed a decreased [EAPC: -1.52; 95% uncertainty interval (UI) -1.66 to -1.37]. Furthermore, both the number and rates of deaths and DALYs decreased over time. It was observed that females had lower rates compared to males. Among all regions, the high-income Asia Pacific region exhibited the highest ASIR (14.09/100,000; 95% UI 12.30/100,000 - 16.39/100,000) in 2021, with an EPAC for ASIR < 0 indicating decreasing trend over time for SAH ASIR. Oceania recorded the highest age-standardized mortality rates (ASMRs) and age-standardized DALYs rates among all regions in 2021 at values of respectively 8.61 (95% UI 6.03 - 11.95) and 285.62 (95% UI 209.42 - 379.65). The burden associated with SAH primarily affected individuals aged between 50 - 69 years old. Metabolic risks particularly elevated systolic blood pressure were identified as the main risk factors contributing towards increased disease burden associated with SAH when compared against environmental or occupational behavioral risks evaluated within the GBD framework.

CONCLUSIONS

The burden of SAH varies by gender, age group, and geographical region. Although the ASRs have shown a decline over time, the burden of SAH remains significant, especially in regions with middle and low-middle SDI levels. High systolic blood pressure stands out as a key risk factor for SAH. More specific supportive measures are necessary to alleviate the global burden of SAH.

Systematic Mendelian Randomization Exploring Druggable Genes for Hemorrhagic Strokes

Patients with hemorrhagic stroke have high rates of morbidity and mortality, and drugs for prevention are very limited. Mendelian randomization (MR) analysis can increase the success rate of drug development by providing genetic evidence. Previous MR analyses only analyzed the role of individual drug target genes in hemorrhagic stroke; therefore, we used MR analysis to systematically explore the druggable genes for hemorrhagic stroke. We sequentially performed summary-data-based MR analysis and two-sample MR analysis to assess the associations of all genes within the database with intracranial aneurysm, intracerebral hemorrhage, and their subtypes. Validated genes were further analyzed by colocalization. Only genes that were positive in all three analyses and were druggable were considered desirable genes. We also explored the mediators of genes affecting hemorrhagic stroke incidence. Finally, the associations of druggable genes with other cardiovascular diseases were analyzed to assess potential side effects. We identified 56 genes that significantly affected hemorrhagic stroke incidence. Moreover, TNFSF12, SLC22A4, SPARC, KL, RELT, and ADORA3 were found to be druggable. The inhibition of TNFSF12, SLC22A4, and SPARC can reduce the risk of intracranial aneurysm, subarachnoid hemorrhage, and intracerebral hemorrhage. Gene-induced hypertension may be a potential mechanism by which these genes cause hemorrhagic stroke. We also found that blocking these genes may cause side effects, such as ischemic stroke and its subtypes. Our study revealed that six druggable genes were associated with hemorrhagic stroke, and the inhibition of TNFSF12, SLC22A4, and SPARC had preventive effects against hemorrhagic strokes.

Cerebrospinal fluid volume as an early radiological factor for clinical course prediction after aneurysmal subarachnoid hemorrhage. A pilot study

BACKGROUND

The pathological mechanisms following aneurysmal subarachnoid hemorrhage (SAH) are poorly understood. Limited clinical evidence exists on the association between cerebrospinal fluid (CSF) volume and the risk of delayed cerebral ischemia (DCI) or cerebral vasospasm (CV). In this study, we raised the hypothesis that the amount of CSF or its ratio to hemorrhage blood volume, as determined from non-contrast Computed Tomography (NCCT) images taken on admission, could be a significant predictor for CV and DCI.

METHODS

The pilot study included a retrospective analysis of NCCT scans of 49 SAH patients taken shortly after an aneurysm rupture (33 males, 16 females, mean age 56.4 ± 15 years). The SynthStrip and Slicer3D software tools were used to extract radiological factors - CSF, brain, and hemorrhage volumes from the NCCT images. The "pure" CSF volume (VCSF) was estimated in the range of [-15, 15] Hounsfield units (HU).

RESULTS

VCSF was negatively associated with the risk of CV occurrence (p = 0.0049) and DCI (p = 0.0069), but was not associated with patients' outcomes. The hemorrhage volume (VSAH) was positively associated with an unfavorable outcome (p = 0.0032) but was not associated with CV/DCI. The ratio VSAH/VCSF was positively associated with, both, DCI (p = 0.031) and unfavorable outcome (p = 0.002). The CSF volume normalized by the brain volume showed the highest characteristics for DCI prediction (AUC = 0.791, sensitivity = 0.80, specificity = 0.812) and CV prediction (AUC = 0.769, sensitivity = 0.812, specificity = 0.70).

CONCLUSION

It was demonstrated that "pure" CSF volume retrieved from the initial NCCT images of SAH patients (including CV, Non-CV, DCI, Non-DCI groups) is a more significant predictor of DCI and CV compared to other routinely used radiological biomarkers. VCSF could be used to predict clinical course as well as to personalize the management of SAH patients. Larger multicenter clinical trials should be performed to test the added value of the proposed methodology.

Exosomal LncRNA TM7SF3-AU1 Aggravates White Matter Injury via MiR-702-3p/SARM1 Signaling After Subarachnoid Hemorrhage in Rats

Subarachnoid hemorrhage (SAH) is a devastating disease associated with a high mortality and morbidity. Exosomes have been considered as a potential therapeutic target for SAH. However, the effect of exosomes in SAH remains to be elucidated. In this study, we focused on investigating the effect of plasma exosomal lncRNA TM7SF3-AU1 in white matter injury after SAH. The SAH model was established by means of endovascular perforation. Exosomes were extracted from rat plasma samples. The expression of RNAs in the exosomes was detected by the transcriptomic microarray. Differentially expressed circRNA, lncRNA, and mRNA were obtained. The ceRNA network showed that the lncRNA TM7SF3-AU1 and miR-702-3p were closely associated with SARM1. Knocking down TM7SF3-AU1 promoted the expression of miR-702-3p and suppressed the expression of SARM1, and knocking down TM7SF3-AU1 also attenuated white matter injury after SAH. In addition, knocking down TM7SF3-AU1 improved the neurological deficits in locomotion, anxiety, learning, memory, and electrophysiological activity after SAH. Mechanistically, TM7SF3-AU1 was able to absorb miR-702-3p, which directly bind the SARM1 mRNA. Furthermore, the white matter injury attenuated by knockdown of TM7SF3-AU1 was partially reversed by the miR-702-3p antagomir in SAH rats. Taken together, this study showed that TM7SF3-AU1 acts as a sponge for miR-702-3p, reducing the inhibitory effect of miR-702-3p on SARM1, resulting in increased SARM1 expression and thus leading to white matter injury after SAH. Our study provides new insights into exosome-associated white matter injury. It also highlights TM7SF3-AU1 as a potential therapeutic target for white matter injury after SAH.

CT perfusion-guided administration of IV milrinone is associated with a reduction in delayed cerebral infarction after subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH) is a singular pathological entity necessitating early diagnostic approaches and both prophylactic and curative interventions. This retrospective before-after study investigates the effects of a management strategy integrating perfusion computed tomography (CTP), vigilant clinical monitoring and standardized systemic administration of milrinone on the occurrence of delayed cerebral infarction (DCIn). The "before" period included 277 patients, and the "after" one 453. There was a higher prevalence of Modified Fisher score III/IV and more frequent diagnosis of vasospasm in the "after" period. Conversely, the occurrence of DCIn was reduced with the "after" management strategy (adjusted OR 0.48, 95% CI [0.26; 0.84]). Notably, delayed ischemic neurologic deficits were less prevalent at the time of vasospasm diagnosis (24 vs 11%, p = 0.001 ), suggesting that CTP facilitated early detection. In patients diagnosed with vasospasm, intravenous milrinone was more frequently administered (80 vs 54%, p < 0.001 ) and associated with superior hemodynamics. The present study from a large cohort of aSAH patients suggests, for one part, the interest of CTP in early diagnosis of vasospasm and DCI, and for the other the efficacy of CT perfusion-guided systemic administration of milrinone in both preventing and treating DCIn.

Agreement between CT-Angiography and Digital Subtraction Angiography in Predicting Angiographic Vasospasm in Patients with Subarachnoid Hemorrhage

Background/Objectives: Digital subtraction angiography (DSA) is the gold standard in the diagnosis of cerebral vasospasm, frequently observed after subarachnoid hemorrhage (SAH). However, less-invasive methods, such as computed tomography angiography (CTA), may be equally accurate. To further clarify comparability, this study evaluated the reliability of CTA in detecting cerebral vasospasm. Methods: This retrospective study included 51 patients with SAH who underwent both CTA and DSA within 24 h. The smallest diameter of the proximal cerebral arterial segments was measured in both modalities at admission and during the vasospasm period. The mean difference in diameter, the intraclass correlation coefficient (ICC) of CTA and DSA, the difference in grade of vasospasm and sensitivity, the specificity and the positive predictive value (PPV) for CTA were calculated. Results: A total of 872 arterial segments were investigated. At time of admission, arterial diameters were significantly smaller on CTA compared to DSA in all segments (-0.26 ± 0.12 mm; p < 0.05). At time of suspected vasospasm (day 9 ± 5), these differences remained significant only for the M1 segment (-0.18 ± 0.37 mm, p = 0.02), the P1 segment (-0.13 ± 0.24 mm, p = 0.04) and the basilar artery (-0.20 ± 0.37 mm, p = 0.0.04). The ICC between CTA and DSA was good (0.5-0.8). The sensitivity of CTA for predicting angiographic vasospasm was 99%, the specificity was 50% and the PPV was 92%. Conclusions: Arterial diameters measured on CTA may underestimate the arterial caliber observed in DSA; however, these absolute differences were minor. Importantly, vessel diameter alone does not fully reflect malperfusion, requiring additional imaging techniques such as CT perfusion.

Impact of thyroid hormone replacement therapy on the course and functional outcome of aneurysmal subarachnoid hemorrhage

BACKGROUND

Thyroid hormones were reported to exert neuroprotective effects after ischemic stroke by reducing the burden of brain injury and promoting post-ischemic brain remodeling.

OBJECTIVE

We aimed to analyze the value of thyroid hormone replacement therapy (THRT) due to pre-existing hypothyroidism on the clinical course and outcome of aneurysmal subarachnoid hemorrhage (SAH).

METHODS

SAH individuals treated between January 2003 and June 2016 were included. Data on baseline characteristics of patients and SAH, adverse events and functional outcome of SAH were recorded. Study endpoints were cerebral infarction, in-hospital mortality and unfavorable outcome at 6 months. Associations were adjusted for outcome-relevant confounders.

RESULTS

109 (11%) of 995 individuals had THRT before SAH. Risk of intracranial pressure- or vasospasm-related cerebrovascular events was inversely associated with presence of THRT (p = 0.047). In multivariate analysis, THRT was independently associated with lower risk of cerebral infarction (adjusted odds ratio [aOR] = 0.64, 95% confidence interval [CI] = 0.41-0.99, p = 0.045) and unfavorable outcome (aOR = 0.50, 95% CI = 0.28-0.89, p = 0.018), but not with in-hospital mortality (aOR = 0.69, 95% CI = 0.38-1.26, p = 0.227).

CONCLUSION

SAH patients with THRT show lower burden of ischemia-relevant cerebrovascular events and more favorable outcome. Further experimental and clinical studies are required to confirm our results and elaborate the mechanistic background of the effect of THRT on course and outcome of SAH.