Subarachnoid Hemorrhage

Bromodomain-containing protein 4 knockdown promotes neuronal ferroptosis in a mouse model of subarachnoid hemorrhage

JOURNAL/nrgr/04.03/01300535-202602000-00041/figure1/v/2025-05-05T160104Z/r/image-tiff Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage. Neuronal ferroptosis in particular plays an important role in early brain injury. Bromodomain-containing protein 4, a member of the bromo and extraterminal domain family of proteins, participated in multiple cell death pathways, but the mechanisms by which it regulates ferroptosis remain unclear. The primary aim of this study was to investigate how bromodomain-containing protein 4 affects neuronal ferroptosis following subarachnoid hemorrhage in vivo and in vitro . Our findings revealed that endogenous bromodomain-containing protein 4 co-localized with neurons, and its expression was decreased 48 hours after subarachnoid hemorrhage of the cerebral cortex in vivo . In addition, ferroptosis-related pathways were activated in vivo and in vitro after subarachnoid hemorrhage. Targeted inhibition of bromodomain-containing protein 4 in neurons increased lipid peroxidation and intracellular ferrous iron accumulation via ferritinophagy and ultimately led to neuronal ferroptosis. Using cleavage under targets and tagmentation analysis, we found that bromodomain-containing protein 4 enrichment in the Raf-1 promoter region decreased following oxyhemoglobin stimulation in vitro . Furthermore, treating bromodomain-containing protein 4-knockdown HT-22 cell lines with GW5074, a Raf-1 inhibitor, exacerbated neuronal ferroptosis by suppressing the Raf-1/ERK1/2 signaling pathway. Moreover, targeted inhibition of neuronal bromodomain-containing protein 4 exacerbated early and long-term neurological function deficits after subarachnoid hemorrhage. Our findings suggest that bromodomain-containing protein 4 may have neuroprotective effects after subarachnoid hemorrhage, and that inhibiting ferroptosis could help treat subarachnoid hemorrhage.

10% carbon dioxide improves cognitive function after subarachnoid hemorrhage in rats: inhibiting neuronal apoptosis through the PI3K/AKT signaling pathway

Many patients experience long-term cognitive dysfunction after subarachnoid hemorrhage (SAH), and effective treatments are currently lacking. Carbon dioxide (CO 2 ), an inexpensive and easily produced gas, forms carbonic acid when dissolved in water. Studies have suggested that hypercapnia may have neuroprotective effects. However, the optimal concentration of CO 2 for therapeutic inhalation is still unclear. This study aimed to investigate the effects of various CO 2 concentrations on cognitive function in SAH rats and to explore the potential molecular mechanisms involved. In this study, we established a rat model of SAH by endovascular perforation of the internal carotid artery. The rat models inhaled CO 2 at concentrations of 10%, 20%, or 30%, for 1 hour after modeling. The results showed that inhalation of 10% CO 2 improved cortical blood flow following SAH, while higher concentrations of CO 2 (20% and 30%) worsened cortical hypoperfusion. The partial pressure of CO 2 did not change 1 hour after SAH, but it significantly increased with the inhalation of 10% CO 2 . Additionally, 10% CO 2 effectively inhibited neuronal apoptosis, enhanced locomotor activity, and improved memory and learning abilities in SAH rats. Moreover, 10% CO 2 upregulated the phosphorylation of phosphatidylinositol 3 kinase) and protein kinase B, increased the expression of Bcl-2, and decreased the expression of Bax. In conclusion, inhaling 10% CO 2 restores cerebral perfusion, inhibits neuronal apoptosis, and improves cognitive function in SAH rats. In contrast, higher concentrations of CO 2 led to worsened hypoperfusion. The neuroprotective effect of 10% CO 2 may occur through the activation of the phosphatidylinositol 3-kinase/protein kinase B signaling pathway.

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.

Natural history of small incidental intracranial aneurysms: a systematic review and pooled analysis on the influence of follow-up duration and aneurysm location on rupture risk reporting

BACKGROUND

The rising detection of small unruptured intracranial aneurysms (sUIAs) poses a clinical challenge, requiring careful consideration between the low but real risk of rupture and the potential morbidity of intervention. Reported rupture rates vary widely across studies, influenced by heterogeneity in design, patient selection, aneurysm location, and follow-up duration. This study assessed how aneurysm location and follow-up length affect rupture rates in untreated sUIAs.

METHODS

A systematic review and meta-analysis were conducted in line with PRISMA guidelines and registered with PROSPERO (CRD42024601692). Four databases (EMBASE, Ovid MEDLINE, EMCARE, Scopus) were searched for studies from January 2000 onwards reporting longitudinal outcomes for ≥20 untreated sUIAs ≤ 5 mm. The primary outcome was the pooled rupture rate, stratified by location and follow-up duration. Secondary analysis examined aneurysm growth. A random-effects model was used for meta-analysis, with heterogeneity assessed using the I2 statistic. Sensitivity analyses evaluated the robustness of findings.

RESULTS

From 10,694 screened records, 28 studies met inclusion criteria, encompassing 10,495 untreated sUIAs ≤ 5 mm. Over a mean follow-up of 38 months, 97 aneurysms ruptured, yielding a pooled rupture rate of 0.8 % (95 % CI, 0.6-1.2). Rupture risk did not significantly differ by location (p = 0.31): 1.1 % for middle cerebral artery, 3.9 % for anterior cerebral artery, and 0.3 % for para-ophthalmic artery aneurysms. Rupture rates remained consistent across follow-up durations (p = 0.53): 0.8 % for <20 months, 0.8 % for 20-40 months, and 1.2 % for >40 months. Although aneurysm growth appeared more frequent with longer follow-up, this was not statistically significant (p = 0.64).

CONCLUSION

This updated meta-analysis, incorporating novel subgroup analyses by location and follow-up duration, confirms that rupture risk for sUIAs ≤ 5 mm remains low (<1%) over an average 38-month period. However, limited long-term data restrict accurate risk estimation beyond this timeframe, and underreporting of aneurysm location impairs site-specific risk assessment. The trend towards greater aneurysm growth with extended follow-up underscores the importance of continued surveillance.

[Subarachnoid hemorrhage part 1 : Pathophysiology, diagnostics and special forms]

Aneurysmal subarachnoid hemorrhage (SAH) is a rare but life-threatening type of stroke with high mortality. Modern imaging techniques such as computed tomography (CT), CT angiography (CTA) and digital subtraction angiography (DSA) nowadays enable a rapid and reliable diagnosis. In unclear cases, cerebrospinal fluid analysis is an essential component. This first part of the CME article focuses on the pathophysiology, epidemiology and clinical presentation of SAH. In addition to standard diagnostic procedures, special forms such as perimesencephalic SAH and SAH due to intradural dissection are discussed. The goal is to provide a solid basis for the differential diagnostic classification and further clinical management.

Impact of Delayed Admission on Treatment Modality and Outcomes of Aneurysmal Subarachnoid Hemorrhage: A Prefecture-Wide, Multicenter Japanese Study

Background/Objectives: Aneurysmal subarachnoid hemorrhage (SAH) requires prompt treatment, yet hospital admission is occasionally delayed, and the optimal treatment strategy for such patients remains to be established. We aimed to investigate treatment modality, treatment timing, and outcomes in patients with SAH with respect to early versus delayed admission. Methods: A total of 1080 patients with SAH and a defined onset date were included in this prefecture-wide, multicenter, registry-based study. Baseline characteristics, late SAH complications (including vasospasm), and functional outcomes were compared between early and delayed admission groups at Day 4 or later (Day 0 = SAH onset). Additionally, the association of treatment choice (endovascular therapy or direct surgery) with treatment timing was analyzed in the delayed admission group. Results: Delayed admission was observed in 69 (6.4%) patients. The neurological status upon admission was significantly better in the delayed admission group, with more World Federation of Neurological Societies grades I-II (89.8% vs. 56.2% in the early admission group). Delayed admission was significantly associated with an increased incidence of symptomatic vasospasm by multivariable logistic regression analysis (odds ratio 2.51: 95% confidence interval 1.26-5.00, p = 0.009), while a significant difference in poor functional outcomes (modified Rankin scale 3-6) was not revealed. Although endovascular therapy use did not increase in the delayed admission group, the interval from admission to endovascular therapy was significantly shorter than that in the direct surgery group (0 [0-1] days vs. 1 [1-8] days: median [interquartile range], p = 0.007, Mann-Whitney U test). Conclusions: Delayed admission was a risk factor for symptomatic vasospasm; however, functional outcomes were not exacerbated. These results were obtained under the treatment strategy of multiple institutions, where the timing of endovascular therapy was earlier than that of direct surgery in patients with delayed admission.

Development of a deep-learning algorithm for etiological classification of subarachnoid hemorrhage using non-contrast CT scans

OBJECTIVES

This study aims to develop a deep learning algorithm for differentiating aneurysmal subarachnoid hemorrhage (aSAH) from non-aneurysmal subarachnoid hemorrhage (naSAH) using non-contrast computed tomography (NCCT) scans.

METHODS

This retrospective study included 618 patients diagnosed with SAH. The dataset was divided into a training and internal validation cohort (533 cases: aSAH = 305, naSAH = 228) and an external test cohort (85 cases: aSAH = 55, naSAH = 30). Hemorrhage regions were automatically segmented using a U-Net + + architecture. A ResNet-based deep learning model was trained to classify the etiology of SAH.

RESULTS

The model achieved robust performance in distinguishing aSAH from naSAH. In the internal validation cohort, it yielded an average sensitivity of 0.898, specificity of 0.877, accuracy of 0.889, Matthews correlation coefficient (MCC) of 0.777, and an area under the curve (AUC) of 0.948 (95% CI: 0.929-0.967). In the external test cohort, the model demonstrated an average sensitivity of 0.891, specificity of 0.880, accuracy of 0.887, MCC of 0.761, and AUC of 0.914 (95% CI: 0.889-0.940), outperforming junior radiologists (average accuracy: 0.836; MCC: 0.660).

CONCLUSION

The study presents a deep learning architecture capable of accurately identifying SAH etiology from NCCT scans. The model's high diagnostic performance highlights its potential to support rapid and precise clinical decision-making in emergency settings.

KEY POINTS

Question Differentiating aneurysmal from naSAH is crucial for timely treatment, yet existing imaging modalities are not universally accessible or convenient for rapid diagnosis. Findings A ResNet-variant-based deep learning model utilizing non-contrast CT scans demonstrated high accuracy in classifying SAH etiology and enhanced junior radiologists' diagnostic performance. Clinical relevance AI-driven analysis of non-contrast CT scans provides a fast, cost-effective, and non-invasive solution for preoperative SAH diagnosis. This approach facilitates early identification of patients needing aneurysm surgery while minimizing unnecessary angiography in non-aneurysmal cases, enhancing clinical workflow efficiency.

IL-33 exerts neuroprotective effects through activation of ST2/AKT signaling axis in microglia after subarachnoid hemorrhage in rats

BACKGROUND AND PURPOSE

ST2, a member of the interleukin-1 (IL-1) receptor family, along with its ligand IL-33, plays critical roles in immune regulation and inflammatory responses. This study investigates the roles of endogenous IL-33/ST2 signaling in subarachnoid hemorrhage (SAH) and elucidates the underlying mechanisms.

METHODS

Dynamic changes in endogenous IL-33 levels were examined following SAH induction in vivo. Rats underwent the endovascular perforation model of SAH and were randomly assigned to receive either recombinant IL-33 (rIL-33) or a vehicle, administered intranasally 1 h post-SAH. ST2 siRNA or an AKT selective inhibitor was administered intraperitoneally (i.p.) 48 h prior to SAH induction to explore the potential mechanisms of IL-33-mediated neuroprotection.

RESULTS

Endogenous IL-33 and ST2 levels were elevated in in vitro models of SAH. Exogenous IL-33 significantly alleviated neuronal apoptosis, reduced brain edema, and enhanced short-term neurofunction in a dose-dependent manner following SAH in rats.

CONCLUSION

Exogenous rIL-33 alleviates SAH-induced neurological deficits by promoting M2-like polarization of microglia post-SAH. These findings suggest a potential role of the microglial ST2/AKT axis in IL-33-related neuroprotection, which warrants further investigation.

Assessing Glibenclamide's efficacy on functional recovery in aneurysmal subarachnoid hemorrhage: A meta-analysis of randomized controlled trials

INTRODUCTION

Glibenclamide, a sulfonylurea receptor 1 (SUR1) inhibitor initially developed for diabetes, has shown potential in reducing cerebral edema and neuroinflammation. This study evaluates its efficacy in improving functional outcomes and reducing complications in aSAH.

METHODS

Databases including PubMed, EMBASE, and Web of Science were searched for RCTs assessing Glibenclamide's effects in aSAH. Outcomes included modified Rankin Scale (mRS), mortality, rebleeding risk, hydrocephalus incidence, and hospital stay duration. Risk Ratio (RR) and Mean Differences (MD) were calculated using random- or fixed-effects models based on heterogeneity (I² statistic).

RESULTS

Four RCTs (290 participants) met inclusion criteria. No significant differences were found in mRS scores at 90 days (MD: 0.06, 95 % CI: -0.59-0.71, p = 0.86) or 180 days (MD: -0.43, 95 % CI: -1.09-0.23, p = 0.20). Similarly, mortality (RR: 0.87, 95 % CI: 0.49-1.54, p = 0.665), rebleeding risk (RR: 0.78, 95 % CI: 0.23-2.60, p = 0.639), hydrocephalus incidence (RR: 1.64, 95 % CI: 0.96-2.79, p = 0.064), and hospital stay (MD: 0.09 days, 95 % CI: -2.15-2.32, p = 0.94) showed no significant differences. The meta-regression analysis showed that Glibenclamide dosage (p = 0.0007) and modified Fisher Scale (p = 0.0312) were significantly associated with mRS outcomes, while age (p = 0.1506), WFNS grade (p = 0.1956), and Hunt-Hess Scale (p = 0.1464) had no significant impact.

CONCLUSION

Current evidence indicates that Glibenclamide does not significantly improve outcomes or reduce complications in aSAH. While promising for cerebral edema, larger multicenter RCTs with standardized protocols and extended follow-ups are needed to clarify its role.

Accelerated intracranial time-of-flight MR angiography with image-based deep learning image enhancement reduces scan times and improves image quality at 3-T and 1.5-T

PURPOSE

Three-dimensional time-of-flight magnetic resonance angiography (TOF-MRA) is effective for cerebrovascular disease assessment, but clinical application is limited by long scan times and low spatial resolution. Recent advances in deep learning-based reconstruction have shown the potential to improve image quality and reduce scan times. This study aimed to evaluate the effectiveness of accelerated intracranial TOF-MRA using deep learning-based image enhancement (TOF-DL) compared to conventional TOF-MRA (TOF-Con) at both 3-T and 1.5-T.

MATERIALS AND METHODS

In this retrospective study, patients who underwent both conventional and 40% accelerated TOF-MRA protocols on 1.5-T or 3-T scanners from July 2022 to March 2023 were included. A commercially available DL-based image enhancement algorithm was applied to the accelerated MRA. Quantitative image quality assessments included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contrast ratio (CR), and vessel sharpness (VS), while qualitative assessments were conducted using a five-point Likert scale. Cohen's d was used to compare the quantitative image metrics, and a cumulative link mixed regression model analyzed the readers' scores.

RESULTS

A total of 129 patients (mean age, 64 years ± 12 [SD], 99 at 3-T and 30 at 1.5-T) were included. TOF-DL showed significantly higher SNR, CNR, CR, and VS compared to TOF-Con (CNR = 183.89 vs. 45.58; CR = 0.63 vs. 0.59; VS = 0.73 vs. 0.61; all p < 0.001). The improvement in VS was more pronounced at 1.5-T (Cohen's d = 2.39) compared to 3-T HR and routine (Cohen's d = 0.83 and 0.75, respectively). TOF-DL also outperformed TOF-Con in qualitative image parameters, enhancing the visibility of small- and medium-sized vessels, regardless of the degree of resolution and field strength. TOF-DL showed comparable diagnostic accuracy (AUC: 0.77-0.85) to TOF-Con (AUC: 0.79-0.87) but had higher specificity for steno-occlusive lesions.

CONCLUSIONS

Accelerated intracranial MRA with deep learning-based reconstruction reduces scan times by 40% and significantly enhances image quality over conventional TOF-MRA at both 3-T and 1.5-T.

GPR40 inhibits microglia-mediated neuroinflammation via the NLRP3/IL-1β/glutaminase pathway after subarachnoid hemorrhage

Subarachnoid hemorrhage is one type of strokes with high mortality and disability and there exists several mechanisms in SAH pathology. G-protein-coupled receptor 40 (GPR40) is proven to exert anti-inflammatory effects in several central nervous system (CNS) diseases. However, the precise role of GPR40 in SAH pathogenesis remains largely unknown. In this study, both in vivo and in vitro SAH models were used to investigate the mechanism of GPR40 attenuating neuroinflammation after SAH onset. We found that GPR40 expression in microglia decreased, which promoted IL-1β secretion and aggravated neuronal death after SAH onset. The GPR40 agonist GW9508 attenuated neuronal damage and ameliorated neurological deficits in SAH-model mice. Mechanistically, GPR40 in microglia inhibited pyroptosis, and cytokine production via inhibiting NLRP3/caspase-1/IL-1β pathway. Then the level of IL-1β secreted by microglia and transported to neurons via exosome were decreased, which down-regulated glutaminase, counteracted glutamate accumulation, and facilitated neuronal survival. These results revealed that GPR40 is a novel regulator that inhibits microglia-mediated neuroinflammation and is a potential therapeutic target in SAH therapy.

Predictive outcome factors in the treatment of subarachnoid hemorrhage with hematoma caused by ruptured anterior circulation aneurysms: A monocentric experience

INTRODUCTION

Intracranial aneurysm (IA) rupture accounts for 3% of strokes and is associated with a concerning mortality rate. Subarachnoid hemorrhage with cerebral hematoma (CSAH) often results in a higher mortality rate; however, the optimal treatment approach remains unclear. This study aims to identify factors predicting poor outcomes and mortality in cases of CSAH due to ruptured aneurysms in the anterior cerebral circulation.

METHODS

This study retrospectively included 102 patients with anterior circulation aneurysm ruptures, treated between 2017 and 2019. A multidisciplinary team determined the treatment strategies. Statistical analyses were performed to assess outcomes.

RESULTS

In the bivariate analysis of CSAH related to anterior circulation aneurysm rupture, significant factors associated with morbidity (mRS >2 at one year follow-up) and mortality were: WFNS score severity, mydriasis, Tako-Tsubo, and the presence of hydrocephalus. In the multivariate analysis, significant factors for mortality were hydrocephalus (p < 0.01) and Tako-Tsubo (p < 0.001), while significant factors for morbidity were hydrocephalus (p < 0.01) and hematoma volume (p = 0.012).

CONCLUSION

Our study analyzed a series of cases involving CSAH from anterior circulation aneurysms. We emphasize the importance of prompt treatment for hydrocephalus and suggest that the diagnosis of Tako-Tsubo should delay but not prevent treatment. Depending on local ethical standards, treatment abstention could be considered in patients with severe WFNS scores, the presence of mydriasis, hematoma >45 mL, and hydrocephalus. Our findings indicate that life-threatening hematomas are best managed surgically, while smaller, non-life-threatening cases may benefit from endovascular treatment, though further randomized trials are needed for validation.

Eighteen-Year Trends in Subarachnoid Hemorrhage Management and Outcomes: A Single-Center Experience

BACKGROUND

Although subarachnoid hemorrhage-related mortality has decreased in recent years due to improvements in treatment, data on the evolution of 1-year functional outcomes after subarachnoid hemorrhage are lacking. The objective of this study was to evaluate the evolution of patient management and their functional outcomes 1 year after subarachnoid hemorrhage over time in a single high-volume neurosurgical intensive care unit.

METHODS

In this observational retrospective study, all consecutive patients with aneurysmal subarachnoid hemorrhage admitted to our neurosurgical intensive care unit between 2002 and 2019 were included. A poor functional outcome was defined as a modified Rankin Scale score of 4-6. Linear regressions were performed, and relative risk reductions of a poor functional outcome were calculated.

RESULTS

Between 2002 and 2019, 1556 patients were included, of whom 329 (21%) had a poor functional outcome. Over time, the percentage of coiling procedures (p = 0.004) increased, and the percentage of delayed cerebral ischemia (p = 0.03) decreased. One-year mortality decreased over time (p < 0.001), whereas 1-year functional outcome improved (p = 0.002), with a relative risk reduction of poor functional outcomes of 38% (17-54%).

CONCLUSIONS

The 1-year functional outcome of patients with subarachnoid hemorrhage improved between 2002 and 2019, and mortality decreased.

Ox-LDL Induces Neuron Apoptosis and Worsens Neurological Outcomes in aSAH via Fas/FADD Pathway

The aim of this study was to assess the role of Ox-LDL (oxidized low-density lipoprotein) in the clinical prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH) and to investigate the underlying mechanisms in a mouse model of aSAH. Plasma Ox-LDL levels were measured in 50 aSAH patients and in 20 control patients via ELISA. Analysis of the associations between Ox-LDL levels and neurological function was carried out 1 year after discharge. The effects of Ox-LDL on aSAH model behavior and neurological damage were studied via Nissl staining and brain assessments. qRT‒PCR, Western blotting, and FITC/PI apoptosis detection were performed in an aSAH cell model to reveal the effects of Ox-LDL on neurons. Protein docking and Fas knockdown were used to explore the role of the Fas/FADD pathway in the Ox-LDL-induced exacerbation of neuron dysfunction. Among aSAH patients, those with lower Ox-LDL levels (1.755 ± 0.2107 mmol/L) had an mRS score ≤ 2 after one year, whereas those with higher Ox-LDL levels (2.532 ± 0.1860 mmol/L) had an mRS score > 2. Mice that were injected twice weekly with 0.2 ml of Ox-LDL, seven times, experienced increased neurological damage and neuronal apoptosis, activating the Fas/FADD pathway, an effect that was mirrored in the 20 µg/ml Ox-LDL-treated cell model. Blocking Fas/FADD with 170 µg of C75 or siRNA inhibited the apoptotic phenotype both in vivo and in vitro. Ox-LDL promoted neuronal apoptosis via Fas/FADD pathway after aSAH. The inhibition of Ox-LDL could serve as a therapeutic strategy to prevent neuronal damage after aSAH and improve prognostic outcomes.

Subtraction-free artifact-aware digital subtraction angiography image generation for head and neck vessels from motion data

Digital subtraction angiography (DSA) is an essential diagnostic tool for analyzing and diagnosing vascular diseases. However, DSA imaging techniques based on subtraction are prone to artifacts due to misalignments between mask and contrast images caused by inevitable patient movements, hindering accurate vessel identification and surgical treatment. While various registration-based algorithms aim to correct these misalignments, they often fall short in efficiency and effectiveness. Recent deep learning (DL)-based studies aim to generate synthetic DSA images directly from contrast images, free of subtraction. However, these methods typically require clean, motion-free training data, which is challenging to acquire in clinical settings. As a result, existing DSA images often contain motion-affected artifacts, complicating the development of models for generating artifact-free images. In this work, we propose an innovative Artifact-aware DSA image generation method (AaDSA) that utilizes solely motion data to produce artifact-free DSA images without subtraction. Our method employs a Gradient Field Transformation (GFT)-based technique to create an artifact mask that identifies artifact regions in DSA images with minimal manual annotation. This artifact mask guides the training of the AaDSA model, allowing it to bypass the adverse effects of artifact regions during model training. During inference, the AaDSA model can automatically generate artifact-free DSA images from single contrast images without any human intervention. Experimental results on a real head-and-neck DSA dataset show that our approach significantly outperforms state-of-the-art methods, highlighting its potential for clinical use.

Systematic review of artificial intelligence methods for detection and segmentation of unruptured intracranial aneurysms using medical imaging

Unruptured intracranial aneurysms are protuberances that appear in cerebral arteries, and their diagnostic evaluation can be a complex, time-consuming, and exhaustive task. In recent years, computer-aided systems have been developed to improve diagnostic processes. Although the proposed methods have already been reviewed to assess their suitability for clinical use, the segmentation methods have not been reviewed in detail, nor has there been a standardized way to compare segmentation and detection tasks. A systematic review was conducted to examine the technical and methodological factors contributing to this limitation. The analysis encompassed 49 studies conducted between 2019 and 2023 that utilized artificial intelligence methods and any medical imaging modality for the detection or segmentation of intracranial aneurysms. Most of the included studies focused exclusively on detection (57%), magnetic resonance angiography was the predominant imaging modality (47%), and the methodologies generally used 3D imaging as the input (71%). The reported sensitivities ranged from 0.68 to 0.90, specificities from 0.18 to 1.0, false positives per case from 0.18 to 13.8, and the Dice similarity coefficient from 0.53 to 0.98. Variations in aneurysm size were found to have a substantial impact on system performance. Studies were evaluated using a diagnostic accuracy study quality assessment tool, which revealed significant concerns regarding applicability. These concerns primarily stem from the poor reproducibility and inconsistent reporting of metrics. Recommendations for reporting outcomes were made to compare procedures across different types of imaging and tasks.

Liberal or Restrictive Transfusion Strategy in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Genetically proxied liability to migraine and risk of intracranial aneurysm and subarachnoid hemorrhage

BACKGROUND

Observational studies have reported inconsistent relationships between migraine and the risk of intracranial aneurysm and subarachnoid hemorrhage (SAH).

OBJECTIVE

To determine whether genetic liability to migraine is associated with risk of intracranial aneurysm and aneurysmal SAH.

METHODS

This study was designed as a two-sample Mendelian randomization (MR) analysis. Genetic associations with migraine were obtained from a large-scale meta-analysis of five population and clinic-based genome-wide association studies of migraine (102,084 cases and 771,257 controls of European ancestry). Genetic associations with intracranial aneurysm and SAH were obtained from a meta-analysis of 22 population-based genome-wide association studies (7495 cases and 71,934 controls of European ancestry). Findings were corroborated by sensitivity analyses and replicated in an independent sample of combined cases of intracranial aneurysm and SAH (3529 cases and 234,948 controls of Asian ancestry from the Biobank Japan and China Kadoorie Biobanks). In secondary analyses, we investigated the outcomes of extracranial aneurysm in the FinnGen and UK Biobank cohorts (up to 7466 combined cases of thoracic and abdominal aortic aneurysm).

RESULTS

Genetic liability to migraine was associated with increased risk of the combined outcome of unruptured intracranial aneurysm and SAH (odds ratio [OR] of outcome per doubling in migraine liability 1.19, 95% confidence interval [CI] 1.06-1.35; p = 0.005). This finding was replicated in an independent sample (OR 1.15, 95% CI 1.02-1.30; p = 0.027), and there were similar associations across the component outcomes of unruptured intracranial aneurysm (OR 1.20, 95% CI 1.01-1.42; p = 0.035) and SAH (OR 1.18, 95% 1.04-1.33; p = 0.008). These findings were consistent in sensitivity analyses robust to violations of the MR assumptions. In reverse MR analyses, genetic liability to intracranial aneurysm was not associated with migraine (OR 1.03, 95% CI 0.99-1.07; p = 0.141). In a secondary analysis, there were similar associations of genetic liability to migraine with all forms of aortic aneurysm (OR for combined thoracic and aortic aneurysm 1.18, 95% CI 1.10-1.27; p = 8.49 × 10-6).

CONCLUSION

Genetic liability to migraine was associated with increased risk of intracranial and extracranial aneurysms, supporting a causal relationship between liability to migraine and these traits. Further work is needed to identify the biological mechanisms and clinical relevance of these findings.

Sex differences in risk factor relationships with subarachnoid haemorrhage and intracranial aneurysms: A Mendelian randomization study

Background

The prevalence of intracranial aneurysms (IAs) and incidence of aneurysmal subarachnoid haemorrhage (aSAH) is higher in women than in men. Although several cardiometabolic and lifestyle factors have been related to the risk of IAs or aSAH, it is unclear whether there are sex differences in causal relationships of these risk factors.

Aims

The aim of this study was to determine sex differences in causal relationships between cardiometabolic and lifestyle factors and risk of aSAH and IA.

Methods

We conducted a sex-specific two-sample Mendelian randomization study using summary-level data from genome-wide association studies. We analysed low-density lipoprotein cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides, non-HDL-C, total cholesterol, fasting glucose, systolic and diastolic blood pressure, smoking initiation, and alcohol use as exposures, and aSAH and IA (i.e. aSAH and unruptured IA combined) as outcomes.

Results

We found statistically significant sex differences in the relationship between genetically proxied non-HDL-C and aSAH risk, with odds ratios (ORs) of 0.72 (95% confidence interval 0.58, 0.88) in women and 1.01 (0.77, 1.31) in men (p-value for sex difference 0.044). Moreover, genetic liability to smoking initiation was related to a statistically significantly higher risk of aSAH in men compared to women (p-value for sex difference 0.007) with ORs of 3.81 (1.93, 7.52) and 1.12 (0.63, 1.99), respectively, and to a statistically significantly higher IA risk in men compared to women (p-value for sex difference 0.036) with ORs of 3.58 (2.04, 6.27) and 1.61 (0.98, 2.64), respectively. In addition, higher genetically proxied systolic and diastolic blood pressure were related to a higher risk of aSAH and IA in both women and men.

Conclusions

Higher genetically proxied non-HDL-C was related to a lower risk of aSAH in women compared to men. Moreover, genetic liability to smoking initiation was associated with a higher risk for aSAH and IA in men compared to women. These findings may help improve understanding of sex differences in the development of aSAH and IA.

National trends in surgical treatment and clinical outcomes among patients with aneurysmal subarachnoid hemorrhage in the Republic of Korea

OBJECTIVE

In this study, changes in treatment methods and patient prognosis were analyzed using a Korean nationwide medical insurance information database.

METHODS

Patients with subarachnoid hemorrhage who received surgical treatment for cerebral aneurysm from 2005 to 2020 were included. The specific surgery type was classified using the surgical code and according to whether stents were used. Yearly trends in mortality rates and poor prognosis, using tracheostomy as proxy, were analyzed by a simple regression analysis. A multistep logistic regression analysis was performed to evaluate the risk factors of mortality and poor prognosis.

RESULTS

Overall, 83,587 patients were included. Females were predominant (64.5%). Microsurgical clip usage rate decreased by approximately two-thirds from 78.8% in 2005 to 24.4% in 2020. Contrarily, endovascular treatment proportion gradually increased, and stent-assisted coil embolization rate surpassed microsurgical clip usage rate in 2020 (24.6% vs. 24.4%). In the multivariate analysis, endovascular treatment correlated positively with 3-month mortality (hazard ratio [HR]: 1.13, 95% confidence interval [CI]: 1.07-1.19, P<0.0001), although correlated negatively with poor prognosis (tracheostomy) (HR: 0.93, 95% CI: 0.89-0.98, P=0.0050).

CONCLUSIONS

According to the treatment trend analysis, during the 16 years studied, for patients with subarachnoid hemorrhage due to ruptured cerebral aneurysm, the endovascular treatment rate increased rapidly and stent-assisted coil embolization rate surpassed that of microsurgical clip ligation. Diversification of treatment methods has led to a decrease in mortality and improved prognosis.

Impact of Subarachnoid Hemorrhage on Human Glymphatic Function: A Time-Evolution Magnetic Resonance Imaging Study

BACKGROUND

Subarachnoid hemorrhage (SAH) is associated with significant mortality and morbidity. The impact of SAH on human glymphatic function remains unknown.

METHODS

This prospective, controlled study investigated whether human glymphatic function is altered after SAH, how it differs over time, and possible underlying mechanisms. Glymphatic enrichment was examined by intrathecal contrast-enhanced magnetic resonance imaging (MRI, glymphatic MRI), utilizing the MRI contrast agent gadobutrol (Gadovist, Bayer AG, GE; 0.50 mmol) as a cerebrospinal fluid (CSF) tracer. The distribution of the tracer in the brain and the subarachnoid and ventricular CSF spaces was assessed using standardized multi-phase MRI T1 sequences, and between-group differences in percentage change of standardized T1 signal unit ratios over time were analyzed by linear mixed models.

RESULTS

The study comprised 27 patients with SAH (19 female/8 male; 59.3±10.2 years) who were examined <3 months (n=5), 3 to 6 months (n=10), 6 to 12 months (n=5), or >12 months (n=7) after bleed. A sex- and age-matched control group of 22 individuals (15 female/7 male; 55.5±10.5 years) underwent the same glymphatic MRI protocol but had no neurological or CSF disease. The patients with SAH showed a marked impairment of glymphatic enrichment throughout the brain (particularly addressing the cerebral cortex and subcortical white matter), especially after 24 hours. The glymphatic impairment was accompanied by redistribution of CSF tracer from subarachnoid spaces toward ventricles. These alterations were most pronounced after 3 to 6 months and less after 12 months, though with interindividual variation. CSF tracer transport within perivascular subarachnoid spaces was impaired and coincided with impaired glymphatic enrichment.

CONCLUSIONS

Human glymphatic function is severely impaired by SAH, particularly shortly after the event. Glymphatic failure is associated with redistribution of CSF from subarachnoid spaces toward ventricles. SAH-related impairment of fluid transport within perivascular subarachnoid spaces may contribute to reduced glymphatic influx. Since patient groups are small, care should be made when concluding about the impact of time on glymphatic function.

Ginsenoside Rd alleviates early brain injury by inhibiting ferroptosis through cGAS/STING/DHODH pathway after subarachnoid hemorrhage

Ferroptosis, a recently identified form of regulated cell death, is characterized by lipid peroxidation and iron accumulation, plays a critical role in early brain injury after subarachnoid hemorrhage. Ginsenoside Rd, an active compound isolated from ginseng, is known for its neuroprotective properties. However, its influence on SAH-induced ferroptosis remains unclear. In this study, we constructed an SAH model using intravascular perforation in vivo and treated HT22 cells with oxyhemoglobin to simulate the condition in vitro. We observed significant changes in ferroptosis markers, including GPX4 and ACSL4, following SAH. Administration of ginsenoside Rd to both rats and HT22 cells effectively inhibited neuronal ferroptosis induced by SAH, alleviating neurological deficits and cognitive dysfunction in rats. Notably, the neuroprotective properties of ginsenoside Rd were countered by the STING pathway agonist 2'3'-cGAMP. Experiments conducted in vitro and in vivo illustrated that the impacts of ginsenoside Rd were counteracted by the BQR inhibitor. Our findings suggest that ginsenoside Rd mitigates EBI after SAH by suppressing neuronal ferroptosis through the cGAS/STING pathway while upregulating DHODH levels. These outcomes emphasize the potential of ginsenoside Rd as a therapeutic candidate for subarachnoid hemorrhage.

Magnesium as an adjunct to nimodipine in subarachnoid hemorrhage: a meta-analysis

BACKGROUND

Subarachnoid hemorrhage (SAH) is a devastating neurological condition with high morbidity and mortality rates. Although nimodipine is widely used in the management of SAH, the potential benefits of magnesium as adjunct therapy remain unclear. This meta-analysis aimed to evaluate the efficacy and safety of combining magnesium with nimodipine for the management of SAH.

METHODS

A comprehensive literature search was conducted using PubMed, ScienceDirect, Google Scholar, and the Cochrane Library. Randomized controlled trials and prospective cohort studies comparing magnesium plus nimodipine versus nimodipine alone in patients with SAH were included. Key outcomes included cerebral vasospasm (CV), delayed cerebral ischemia (DCI), functional outcomes, mortality, and adverse events.

RESULTS

Twelve studies involving 2,338 patients were included. The combination of magnesium and nimodipine significantly reduced the incidence of CV (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.29-0.95; p=0.03) and DCI (OR, 0.52; 95% CI, 0.31-0.87; p=0.01) compared to nimodipine alone. However, no significant differences were found in functional outcomes (modified Rankin Scale: OR, 0.97; p=0.75; Glasgow Outcome Scale: OR, 0.81; p=0.24), mortality (OR, 0.97; p=0.83), or secondary cerebral infarction (OR, 0.38; p=0.12). The incidence of adverse events was higher in the combination group; however, this difference was not statistically significant (OR, 3.14; p=0.33).

CONCLUSION

Adding magnesium to nimodipine therapy in patients with SAH may help reduce CV and DCI incidence but does not significantly improve functional outcomes or mortality. Further large-scale studies are needed to optimize the dosing regimens and confirm these findings.

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.

Potential of the pharmacological inhibition of CCL2-CCR2 axis via targeting FROUNT to prevent the initiation and the progression of intracranial aneurysms in rats

Intracranial aneurysms (IAs) affect 1%-5% of the public and are a major cause of subarachnoid hemorrhage. Currently, there is no medical treatment to prevent the progression or rupture of IAs. Recent studies have defined IA as a chronic inflammatory disease in which macrophages infiltrate intracranial arteries via the CCL2-CCR2 axis. The chemokine signal regulator FROUNT mediates this axis, and it can be inhibited by the anti-alcoholism drug disulfiram. Therefore, inhibition of macrophage infiltration by interfering with FROUNT using disulfiram may represent a strategy to prevent exacerbation of IAs. Here, effects of disulfiram were investigated in vitro and in an animal model of IAs. FROUNT expression was observed on infiltrated macrophages both in human IAs and in the rat IA model by immunohistochemistry. In vitro treatment with disulfiram suppressed CCL2-mediated migration of cultured rat macrophages in a transwell system. Disulfiram administered in a rat model of IAs inhibited both the initiation and the enlargement of IAs in a dose-dependent manner; this was accompanied by suppression of macrophage infiltration. These results suggest that pharmacological inhibition of the CCL2-CCR2-FROUNT signaling cascade could be a treatment of patients with IAs.

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

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

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.

Animal Models of Intracranial Aneurysms: History, Advances, and Future Perspectives

Intracranial aneurysms (IA) are a disease process with potentially devastating outcomes, particularly when rupture occurs leading to subarachnoid hemorrhage. While some candidates exist, there is currently no established pharmacological prevention of growth and rupture. The development of prophylactic treatments is a critical area of research, and preclinical models using animals play a pivotal role. These models, which utilize various species and induction methods, each possess unique characteristics that can be leveraged depending on the specific aim of the study. A comprehensive understanding of these models, including their historical development, is crucial for appreciating the advantages and limitations of aneurysm research in animal models.We summarize the significant roles of animal models in IA research, with a particular focus on rats, mice, and large animals. We discuss the pros and cons of each model, providing insights into their unique characteristics and contributions to our understanding of IA. These models have been instrumental in elucidating the pathophysiology of IA and in the development of potential therapeutic strategies.A deep understanding of these models is essential for advancing research on preventive treatments for IA. By leveraging the unique strengths of each model and acknowledging their limitations, researchers can conduct more effective and targeted studies. This, in turn, can accelerate the development of novel therapeutic strategies, bringing us closer to the goal of establishing an effective prophylactic treatment for IA. This review aims to provide a comprehensive view of the current state of animal models in IA research.

Skull bone marrow and skull meninges channels: redefining the landscape of central nervous system immune surveillance

The understanding of neuroimmune function has evolved from concepts of immune privilege and protection to a new stage of immune interaction. The discovery of skull meninges channels (SMCs) has opened new avenues for understanding central nervous system (CNS) immunity. Here, we characterize skull bone marrow and SMCs by detailing the anatomical structures adjacent to the skull, the differences between skull and peripheral bone marrow, mainstream animal processing methods, and the role of skull bone marrow in monitoring various CNS diseases. Additionally, we highlight several unresolved issues based on current research findings, aiming to guide future research directions.

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

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

Optical approaches for neurocritical care: Toward non-invasive recording of cerebral physiology in acute brain injury

Acute brain injury (ABI) is a complex disease process that begins with an initial insult followed by secondary injury resulting from disturbances in cerebral physiology. In the metabolically active brain, early recognition of physiologic derangements is critical in enabling clinicians with the insight to adjust therapeutic interventions and reduce risk of ischemia and permanent injury. Current established approaches for monitoring cerebral physiology include the neurologic physical examination, traditional brain imaging such as computed tomography (CT) and magnetic resonance imaging (MRI), electroencephalography (EEG), and bedside modalities such as invasive parenchymal probes and transcranial doppler ultrasound. Diffuse optical spectroscopy (DOS), diffuse correlation spectroscopy (DCS), and optical coherence tomography (OCT) are non-invasive optical techniques that have shown promise in measuring clinically relevant changes in cerebral physiology. These new modalities may offer clinicians significant benefits as they are safe, can be utilized at the point-of-care, and provide continuous measurements. This paper reviews major causes of primary and secondary ABI encountered in neurocritical care units, conventional measures of cerebral physiology during ABI, and emerging non-invasive optical techniques that have significant potential for translation to the bedside.

Visual inspection versus spectrophotometry for xanthochromia detection in patients with sudden onset severe headache-A diagnostic accuracy study

OBJECTIVE

There is still disagreement about whether to routinely use spectrophotometry to detect xanthochromia in cerebrospinal fluid (CSF) or whether visual inspection is adequate. We aimed to evaluate the diagnostic accuracy of these methods in detecting an aneurysmal subarachnoid hemorrhage in patients with sudden onset severe headache.

BACKGROUND

When a patient presents to the emergency department with a headache for which there is suspicion of a subarachnoid hemorrhage, the gold standard to rule this out is to perform a CSF analysis for xanthochromia with or without spectrophotometry if the cranial non-contrast computed tomography (CT) upon admission is negative.

METHODS

Having applied the gold standard, we retrospectively included patients with acute headache who underwent both CT scan and CSF spectrophotometry at our hospital in the period 2002-2020. Patients were excluded if the cranial CT was interpreted as positive, there was a bloody CSF, or if visual assessment data of the CSF was unavailable. We scrutinized the patients' medical records and evaluated the benefit of spectrophotometry compared to visual inspection. The net bilirubin absorbance cut-off for support of subarachnoid hemorrhage was set at >0.007 absorbance units. The spectrophotometry was also considered positive if the net bilirubin absorbance was ≤0.007 and net oxyhemoglobin absorbance was ≥0.1 absorbance units. We calculated and compared the sensitivity and specificity of CSF spectrophotometry and visual inspection of the CSF.

RESULTS

In total, 769 patients, with a mean age of 42.3 ± (standard deviation [SD] = 17.3) years, were included. The headache onset was classified as a thunderclap headache in 41.5%, and 4.7% had a sudden loss of consciousness. Fifteen patients (2%) were finally diagnosed with a subarachnoid hemorrhage, six (0.8%) had an aneurysmal subarachnoid hemorrhage, seven (0.9%) had a perimesencephalic hemorrhage, one (0.1%) had a cortical cerebral sinus venous thrombosis, and one (0.1%) had a spinal epidural hematoma. Four patients (0.5%) had a subarachnoid hemorrhage that was not detected by visual inspection, and two were caused by an aneurysmal rupture. One of these two patients died just before intervention, and the other underwent coiling for an anterior communicating aneurysm. The number needed for lumbar puncture to detect a subarachnoid hemorrhage was 51, but 128 to detect an aneurysmal hemorrhage. The corresponding numbers needed for CSF spectrophotometric analysis were 192 and 385, respectively. Spectrophotometry was positive in 31 patients (4.0%), of whom 18 (2.3%) also had visually detected xanthochromia (11 true positive). The mean net bilirubin absorbance in the 13 samples with visually clear CSF was 0.0111 ± (SD = 0.0103) absorbance units, compared to 0.0017 ± (SD = 0.0013) in the CSF with negative spectrophotometry. The corresponding figures for net oxyhemoglobin absorbance were 0.0391 ± (SD = 0.0522) versus 0.0057 ± (SD = 0.0081). The sensitivity of spectrophotometric xanthochromia detection was 100% (95% confidence interval [CI], 78-100), compared to 73% (95% CI, 45-92) for visual xanthochromia detection. The specificity of spectrophotometric xanthochromia detection was 98% (95% CI, 97-99) compared to 99% (95% CI, 98-100) for visual xanthochromia detection. Both methods had high negative predictive values: 100% (95% CI, 99.5-100) versus 99.5% (95% CI, 98.6-99.9), respectively.

CONCLUSIONS

Both visual inspection and spectrophotometry have high diagnostic accuracy for detecting CSF xanthochromia, but the lower sensitivity of visual assessment makes it unreliable, and we recommend the use of spectrophotometry in clinical practice.

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.

Progressive histological and behavioral deterioration of a novel mouse model of secondary hydrocephalus after subarachnoid hemorrhage

Hydrocephalus commonly occurs after subarachnoid hemorrhage (SAH) and is associated with increased morbidity and disability in patients with SAH. Choroid plexus cerebrospinal fluid (CSF) hypersecretion, obliterative arachnoiditis occluding the arachnoid villi, lymphatic obstruction, subarachnoid fibrosis, and glymphatic system injury are considered the main pathological mechanisms of hydrocephalus after SAH. Although the mechanisms of hydrocephalus after SAH are increasingly being revealed, the clinical prognosis of SAH still has not improved significantly. Further research on SAH is needed to reveal the underlying mechanisms of hydrocephalus and develop translatable therapies. A model that can stably mimic the histopathological and neuroethological features of hydrocephalus is critical for animal experiments. There have been fewer animal studies on hydrocephalus after SAH than on other stroke subtypes. The development of a reproducible and effective model of hydrocephalus after SAH is essential. In this study, we establish a mouse model of SAH that stably mimics brain injury and hydrocephalus after SAH through injections of autologous blood into the cisterna magna via different methods and characterize the model in terms of neurological behavior, histology, imaging, neuronal damage, and white matter damage.

Analysis of delayed cerebral ischemia incidence after treatment for aneurysmal subarachnoid hemorrhage in young adults: A cohort study

Background

This study aimed to analyze the incidence of delayed cerebral ischemia (DCI) and outcome stratified by age in patients who suffered aneurysmal subarachnoid hemorrhage.

Methods

A cohort study with patients from Christ the Redeemer Hospital from 2014 to 2020, with 359 patients separated into 2 groups, 48 of them aged under 40 years and 311 aged 40 years or over.

Results

In patients under 40 years of age, DCI was found in 81.3%, while in patients aged 40 or over, it was 61.4%. A relative risk of 1.32 (confidence interval: 1.12-1.55), with P = 0.013. After multivariate assessment, patients aged under 40 years were found to have a 27-39% higher risk of presenting DCI.

Conclusion

We identified that age under 40 years is a risk factor for the occurrence of DCI.

Development of an indicator framework for assessing nursing quality in interventional therapy for intracranial aneurysms in China

Objective

The objective of this study is to devise an indicator system to assess the quality of nursing care in the context of interventional therapy for intracranial aneurysms (IA) in China. This will furnish a standardized and quantitative framework for the monitoring and assessment of nursing quality within the IA interventional therapeutic field.

Methods

The indicators and their associated weights within the evaluation system for nursing quality in interventional therapy for IA were determined based on the theoretical framework of the three-dimensional quality model, specifically the "structure-process-outcome" paradigm. This was achieved by using several methodological approaches, such as literature analysis, semi-structured interviews, expert consultations, the Delphi method, and the analytic hierarchy process.

Results

Expert consultations were conducted over two rounds, with questionnaires distributed via email and WeChat. Both rounds yielded a questionnaire return rate of 100%. Across these consultations, pertinent statistical measures were obtained, such as the expert authority coefficient (Cr), the coefficient of variation (CV), and Kendall's harmony coefficient, which exhibited values of 0.886 and 0.952, 0-0.193 and 0-0.185, and 0.138 and 0.149, respectively. These findings indicated statistically significant differences (p < 0.01). Notably, the indicators within the final iteration of the evaluation system for nursing quality in interventional therapy for IA are categorized into 3 tiers: primary indicators, encompassing 3 metrics; secondary indicators, comprising 10 metrics; and tertiary indicators, consisting of 36 indicators.

Conclusion

The indicator system devised for assessing nursing quality in interventional therapy for IA, as outlined in this study, possesses a high level of scientific rigor and reliability in China. It aptly captures the unique nuances inherent in IA management during interventional therapy nursing, thereby serving as a valuable reference point for the assessment of nursing quality within the context of IA interventional therapy.

Real-Time Surgical Planning for Cerebral Aneurysms Treated With Intrasaccular Flow Disruption Devices Based on Fast Virtual Deployment and Discrete Element Method

This study introduces an innovative real-time surgical planning platform optimized for the treatment of arterial aneurysms using intrasaccular flow disruption (IFD) devices. This platform incorporates a cutting-edge fast virtual deployment (FVD) algorithm alongside a discrete element method (DEM) for computational fluid dynamics (CFD) analyses. It facilitates the efficient virtual deployment of IFD devices, minimizing computational overhead while allowing for comprehensive postoperative hemodynamic efficacy assessment. The FVD algorithm employs an adaptive wall adherence and curvature control system, validated through both idealized and patient-specific model simulations. Post-treatment hemodynamic shifts are quantified by discretizing device wire filaments into discrete particles, which are then integrated with blood flow simulations for enhanced realism. The FVD algorithm efficiently executes virtual deployment of IFD devices within seconds, producing DEM-CFD computational models that align closely with bench testing, traditional Finite Element Method (FEM) analyses, and angiographic data. DEM-CFD outcomes link occlusion effectiveness to post-implantation hemodynamic characteristics, influenced by the aneurysm's unique anatomical features and clinical intervention strategies. The proposed platform demonstrates substantial improvement in balancing computational efficiency with analytical precision. It provides a viable and innovative framework for real-time surgical planning, presenting significant implications for clinical application in arterial aneurysm management.

Numerical investigation of unruptured middle cerebral artery bifurcation aneurysms: influence of aspect ratio

An aneurysm is a disease condition, which is due to the pathological weakening of an arterial wall. These aneurysms are often found in various branch points and bifurcations of an artery in the cerebral circulation. Most aneurysms come to medical attention, either due to brain hemorrhages caused by rupture or found unruptured. To consider surgically invasive treatment modalities, clinicians need scientific methods such as, hemodynamic analysis to assess rupture risk. The arterial wall loses its structural integrity when wall shear stress (WSS) and other hemodynamic parameters exceed a certain threshold. In the present study, numerical simulations are carried out for unruptured middle cerebral artery (MCA) aneurysms. Three distinct representative sizes are chosen from a larger patient pool of 26 MCA aneurysms. Logically, these aneurysms represent three growth stages of any patient with similar anatomical structure. Simulations are performed to compare the three growth phases (with different aspect ratios) of an aneurysm and correlate their hemodynamic parameters. Simulations with patient specific boundary conditions reveal that, aneurysms with a higher aspect ratio (AR) correspond to an attendant decrease in both time-averaged wall shear stress (TAWSS) and spatial wall shear stress gradients (WSSG). Smaller MCAs were observed to have higher positive wall shear stress divergence (WSSD), exemplifying the tensile nature of arterial wall stretching. Present study identifies positive wall shear stress divergence (PWSSD) to be a potential biomarker for evaluating the growth of an aneurysm.

Insulin Resistance Predicts Prognosis in Patients With Subarachnoid Hemorrhage

OBJECTIVE

The objective of this study was to determine whether insulin resistance (IR) could be used as a predictor of poor prognosis at 3 months after subarachnoid hemorrhage (SAH).

METHODS

The study included patients aged 18 years or older with a confirmed diagnosis of SAH due to ruptured aneurysm from January 2021 to March 2024. Patients with confirmed diabetes mellitus and taking glucose-lowering drugs, or taking lipid-lowering drugs, or SAH not due to ruptured aneurysm, or comorbid systemic diseases were excluded. Patients were classified into good prognosis (modified Rankin scale [MRS] 0-2) and poor prognosis (MRS 3-6). Receiver operating characteristic curve (ROC), least absolute shrinkage and selection operator (LASSO) analysis, and multivariate logistic regression analysis were used to determine the potential of triglyceride-glucose (TyG) index and the triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio as predictors of poor prognosis. Finally, a prognostic prediction model based on IR was constructed.

RESULTS

A total of 358 patients were included in this study. Poor prognosis patients had higher age, BMI, hypertension percentage, glucose, triglycerides, TyG index and TG/HDL ratio, and lower HDL. ROC, LASSO, and multivariate logistic regression analysis revealed that age, glucose, TyG index, and TG/HDL ratio had significant potential to predict the prognosis of SAH patients. The prognostic prediction model constructed by combining age, glucose, TyG index, and TG/HDL ratio had high discriminatory power (area under the curve [AUC] = 0.80), satisfactory calibration curves, and good clinical utility.

CONCLUSION

IR is strongly associated with the prognosis of SAH patients, and the combination of age, glucose, TyG index, and TG/HDL ratio can provide a new direction for future treatment.

External Bleeding and Advanced Biomacromolecules for Hemostasis

Hemorrhage is a significant medical problem that has been an active area of research over the past few decades. The human body has a complex response to bleeding that leads to blood clot formation and hemostasis. Many biomaterials based on various biomacromolecules have been developed to either accelerate or improve the body's natural response to bleeding. This review examines the mechanisms of hemostasis, types of bleeding, and the in vitro or in vivo models and techniques used to study bleeding and hemostatic materials. It provides a detailed overview of the diverse hemostatic materials, including those that are highly absorbent, wet adhesives, and those that accelerate the biochemical cascade of blood clotting. These materials are currently marketed, under preclinical testing, or being researched. In exploring the latest advancements in hemostatic technologies, this paper highlights the potential of these materials to significantly improve bleeding control in clinical and emergency situations.

Trajectory clustering of immune cells and its association with clinical outcomes after aneurysmal subarachnoid hemorrhage

Background and purpose

The immune response following aneurysmal subarachnoid hemorrhage (aSAH) can exacerbate secondary brain injury and impact clinical outcomes. As the immune response after aSAH is a dynamic process, we aim to track and characterize immune cell trajectories over time to identify patterns associated with various clinical outcomes.

Methods

In this retrospective single-center study of patients with aSAH, we analyzed immune cell count trajectories, including neutrophil, monocyte, and lymphocyte counts, collected from day 1 to day 14. These trajectories were classified into four distinct clusters utilizing the k-means longitudinal clustering method. A comprehensive multivariable analysis was performed to explore the associations of these immune cell clusters with various clinical outcomes. These outcomes included a Modified Rankin Scale score (mRS) of 3 to 6, indicative of poor functional outcomes, along with complications including shunt dependency, vasospasm, and secondary cerebral infarction.

Results

In this study, 304 patients with aSAH were analyzed. The trajectories of immune cell counts, including neutrophils, monocytes, and lymphocytes, were successfully categorized into four distinct clusters for each immune cell type. Within neutrophil clusters, both persistent neutrophilia and progressive neutrophilia were associated with poor functional outcomes, shunt dependency, and vasospasm, with resolving neutrophilia showing a lesser degree of these associations. Within monocyte clusters, early monocytosis was associated with vasospasm, whereas delayed monocytosis was associated with shunt dependency. Within lymphocyte clusters, both early transient lymphopenia and early prolonged lymphopenia were associated with poor functional outcomes.

Conclusion

Our study demonstrates that distinct immune cell trajectories post-aSAH, identified through unsupervised clustering, are significantly associated with specific clinical outcomes. Understanding these dynamic immune responses may provide key insights with potential for future therapeutic strategies.

Inverse Association between the Body Mass Index and the Incidence of Unruptured Intracranial Aneurysms-Insights from the Hamburg City Health Population Study

Overweight/obese patients experience a lower incidence of subarachnoid hemorrhage (SAH) compared to non-overweight patients, even though elevated body mass index (BMI) has been associated with various SAH risk factors. Given that intracranial aneurysms are a primary cause of SAH, a potential protective effect of a high BMI on intracranial aneurysms is likely but remains insufficiently investigated. This population-based MRI study aims to conduct detailed analyses on risk factors associated with the incidence of unruptured intracranial aneurysms (UIA). Retrospective analysis of subjects enrolled in the prospective Hamburg City Health study who underwent intracranial magnetic resonance imaging (MRI) was done. MRI scans were screened for UIA using time-of-flight angiography. Subject data including medical history, laboratory examinations, and risk factors for UIA were collected, and a multivariable logistic regression model was used to investigate the relationship between risk factors and UIA incidence. 2688 subjects (mean (IQR) age, 65 (58-71); 1176 female (43.8%) were included. An UIA was detected in 214 subjects with an incidence of 10.6% (6.0%) in females (males). Determinants for UIA were female sex (OR 2.00, 95%CI 1.45-2.77, p < 0.001), hypertension (OR 1.48, 95%CI 1.08-2.04, p = 0.015), smoking (OR 1.41, 95%CI 1.03-1.95, p = 0.036), and BMI (OR 0.95, 95%CI 0.91-0.98, p = 0.004). Among subjects with UIA, 9.4% with a BMI > 25 had multiple aneurysms, compared to 21.6% with BMI ≤ 25 (p = 0.012). This study suggests that a high BMI exhibits a protective effect on UIA incidence and the development of multiple aneurysms. Additionally, the data confirms established risk factors for UIA development, such as female sex, hypertension, and smoking.

Role of disturbed wall shear stress in the development of cerebral aneurysms

Although the hemodynamics of cerebral aneurysms have been extensively studied using patient-specific computational fluid dynamics techniques, no specific hemodynamic factors characteristic of cerebral aneurysm development have yet been identified. We believe that one problem with previous hemodynamic studies of cerebral aneurysms has been the manner in which control groups were created for comparison with experimental groups. The purpose of this study was to determine hemodynamic factors that correlated with the development of cerebral aneurysms. The control group was established in a manner that differed from those of previous works. This allowed us to demonstrate the effectiveness of our method. We artificially removed aneurysms in the middle cerebral artery bifurcations of nine patients and reconstructed the vessel geometries before the aneurysms had occurred. Pulsatile blood flow simulations were performed using the vessel geometries ipsilateral and contralateral to the sites of aneurysm removal, and hemodynamic metrics were calculated. Use of the ipsilateral and contralateral sides as the experimental and control sites, respectively, allowed us to evaluate statistically the hemodynamic metrics between the two corresponding sites/groups. The results showed that only the normalized transverse wall shear stress (NtransWSS) was significantly higher at the MCA bifurcation ipsilateral to the site of aneurysm removal than at the contralateral bifurcation (p = 0.01). There were no significant differences in the other hemodynamic metrics between the bilateral bifurcations. Our findings imply that multi-directional disturbed wall shear stress, which is detected by the NtransWSS metric, may be one hemodynamic risk factor for the development of cerebral aneurysms.

Birth weight and risk of cerebral aneurysm: A multivariable Mendelian randomization study

BACKGROUND

Birth weight has been linked with various health outcomes. The association between birth weight and cerebral aneurysm remains unknown.

METHODS

The two-sample Mendelian randomization (MR) approach was used to evaluate the causal effect of birth weight on cerebral aneurysm based on genome-wide association studies (GWAS), comprising 261,932 UKB participants for birth weight and 204,060 FinnGen participants for cerebral aneurysm. The inverse variance weighted (IVW) method was used as the primary method. Alternative methods were used for comparison. Sensitivity analysis was conducted to evaluate the robustness of the results. Multivariable MR (MVMR) was further conducted to evaluate the direct effect of the birth weight on cerebral aneurysm.

RESULTS

The IVW detected a causal association between higher birth weight and increased risk of cerebral aneurysm (OR = 0.521, 95% CI = 0.356 ∼ 0.763, P = 7.88 × 10-4), which was supported by alternative MR models. Sensitivity analysis did not find any evidence of heterogeneity or pleiotropy. MVMR further identified a direct effect of birth weight on cerebral aneurysm, independent of obesity-related traits or smoking.

CONCLUSION

This MR study found evidence of the association between birth weight and cerebral aneurysm, providing novel insight into the etiology of cerebral aneurysm, indicating the promising role of birth weight as a marker for screening populations at higher risk of cerebral aneurysm.

Trends in Hospitalization and Mortality Rates Associated with Subarachnoid Hemorrhage and Unruptured Cerebral Aneurysms in Brazil

BACKGROUND

Epidemiology of spontaneous subarachnoid hemorrhage (SAH) and unruptured intracranial aneurysm (UIA) is valuable for determining neurosurgical and general health care effectiveness. There is an information gap regarding these conditions in middle- and low-income countries. Therefore, we aimed to investigate hospitalization and mortality rates for SAH and UIA in Brazil from 2011 to 2019.

METHODS

This observational, population-based study used hospital admission and mortality data and included all SAH- and UIA-related public hospitalizations and deaths occurring from 2011 to 2019. Data were obtained from the Ministry of Health National Hospitalisation and Mortality Information Systems. Population data were obtained from the Brazilian Institute of Geography and Statistics. Simple linear regression models with normal responses were adjusted to explain the temporal evolution of variables. Joinpoint regression models were adjusted to detect moments of significant change in variable behavior. Graduated choropleth maps were generated using georeferencing and geospatial analyses.

RESULTS

Annual SAH hospitalization and mortality coefficients were 4.81/100,000 and 2.49/100,000 persons, respectively. UIA hospitalization and mortality coefficients were 1.21/100,000 and 0.24/100,000 persons, respectively. In addition to regional differences, we found a stable SAH hospitalization trend and an increasing mortality rate of 0.062 cases/100,000 inhabitants annually. The UIA hospitalization rate increased by 0.074 cases/100,000 inhabitants annually, and mortality decreased by 0.07 deaths/100,000 inhabitants annually.

CONCLUSIONS

In Brazil, the SAH hospitalization trend is stable, although there is a worrisome increasing SAH-related mortality trend. A better scenario was observed for UIA, with an increase in hospitalizations and decrease in mortality.

BL-918 alleviates oxidative stress in rats after subarachnoid hemorrhage by promoting mitophagy through the ULK1/PINK1/Parkin pathway

BACKGROUND AND PURPOSE

Oxidative stress plays a critical role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). The small molecule ULK1 agonist, BL-918, demonstrated neuroprotective effects in other central nervous system diseases; however, its role in SAH has not yet been explored. This study aimed to evaluate whether BL-918 could provide neuroprotective effects in rats following SAH.

METHODS

An SAH model was established in Sprague-Dawley rats using endovascular perforation. BL-918 was administered intraperitoneally after SAH, while the ULK1 inhibitor SBI was given intraperitoneally prior to SAH modeling. PINK1 siRNA was administered into the lateral ventricle before SAH induction. The neuroprotective effects and mechanisms of BL-918 were assessed through SAH grading, brain water content measurement, blood-brain barrier permeability, neurobehavioral tests, Western blot, immunofluorescence, TUNEL staining, DHE staining, and transmission electron microscopy (TEM).

RESULTS

After SAH, the expression levels of p-ULK1, PINK1, Parkin, and LC3Ⅱ increased, peaking at 24 h post-SAH. BL-918 treatment improved neurological function in rats, reduced brain water content and blood-brain barrier permeability, and exhibited anti-oxidative stress and anti-apoptotic effects. Western blot analysis revealed that BL-918 increased the expression of p-ULK1, PINK1, Parkin, LC3Ⅱ, Bcl-xl, and Bcl-2 while inhibiting the expression of Bax and Cleaved Caspase-3. Oxidative stress-related indicators showed that BL-918 alleviated oxidative stress. Immunofluorescence and TEM results demonstrated that BL-918 promoted mitophagy and preserved mitochondrial morphology. Furthermore, the positive effects of BL-918 were reversed by SBI and PINK1 siRNA, respectively.

CONCLUSION

BL-918 improved both short-term and long-term neurological impairments in rats after SAH and reduced oxidative stress by promoting mitophagy, at least partially through the ULK1/PINK1/Parkin signaling pathway.

Oral microbiome dysbiosis may be associated with intra cranial aneurysms

BACKGROUND

Although the etiology of aneurysms remains elusive, recent advances in high-throughput sequencing technology and ongoing human microbiome investigations suggest a potential link between microbiome composition and the onset of various human diseases.

OBJECTIVE

This study aimed to utilize high-throughput 16 S rRNA gene sequencing to analyze the oral flora bacterial profiles of individuals, comparing patients with intracranial aneurysms to a healthy control group. Importantly, we sought to identify differences in the oral microbiota and offer novel insights and methods for early diagnosis and identification of intracranial aneurysms.

METHOD

Saliva samples were collected from 60 patients with cerebral aneurysms (case group) and 130 healthy individuals (control group). The V3-V4 region of the bacterial 16 S rRNA gene was amplified and sequenced using the HiSeq high-throughput sequencing platform to establish the bacterial profile. Sequencing data were analyzed using QIIME2 and Metastats software to compare composition differences and relative abundance at the phylum and genus levels in the oral microbiota of the two groups.

RESULTS

Significant differences in oral microbiota composition were observed between patients in the case and control groups (P < 0.05). Genus-level identification highlighted key positions occupied by Eubacterium, Saccharimonadaceae, Rothia, Gemella, Streptococcus, Lactobacillales, Phocaeicola, Bacteroides, Saccharimonadales, and Abiotrophia.

CONCLUSION

This study revealed noteworthy distinctions in the composition, abundance, and diversity of oral microbiota between intracranial aneurysm patients and healthy controls. These disparities suggest a potential correlation between oral microbiota and the development of intracranial aneurysms, offering new avenues for early diagnosis and intervention. However, limitations such as a small sample size, lack of prospective design, and absence of causal inference warrant further validation and exploration.

Peroxiredoxin-5 alleviates early brain injury after subarachnoid hemorrhage by reducing oxidative stress

BACKGROUND AND PURPOSE

Following subarachnoid hemorrhage (SAH), excessive activation of oxidative stress and cell apoptosis plays a critical role in early brain injury (EBI). Peroxiredoxin-5 (Prdx5), predominantly expressed in neuronal mitochondria, acts as an antioxidant. However, the role of Prdx5 in EBI after SAH remains unclear. This study aims to elucidate the antioxidative stress and anti-apoptotic effects of Prdx5 in rats following SAH.

METHODS

In this study, an SAH model was established in Sprague-Dawley rats using endovascular perforation. Recombinant Prdx5 (rPrdx5) was administered intranasally to upregulate Prdx5 expression after SAH in rats. Prdx5 small interfering RNA (Prdx5 siRNA) was administered prior to SAH modelling. The neuroprotective effects of Prdx5 were validated through SAH grading, brain water content, blood-brain barrier permeability, neurobehavioral tests, immunofluorescence, TUNEL staining, and Western blotting.

RESULTS

The expression levels of endogenous Prdx5 significantly decreased after SAH. Treatment with rPrdx5 improved both short-term and long-term behaviour in rats, reduced brain water content and blood-brain barrier permeability, and exhibited anti-oxidative stress and anti-apoptotic effects. Measurements of oxidative stress-related indicators, including MDA, SOD, GSH-Px and GSH/GSSG, confirmed that Prdx5 can alleviate oxidative stress in rats after SAH. Western blot analysis showed that rPrdx5 significantly increased the expression of Bcl-XL and Bcl-2 and reduced the expression of Bax and Cleaved Caspase-3, thereby exerting anti-apoptotic effects. Additionally, Prdx5 siRNA reversed the neuroprotective effects of rPrdx5, exacerbated neuronal damage and blood-brain barrier permeability, and increased levels of oxidative stress and apoptosis.

CONCLUSION

In conclusion, our study demonstrated that specifically upregulating the expression of Prdx5 can reduce oxidative stress and apoptosis in rats after SAH, while also improving both short-term and long-term neurological impairments. Prdx5 is primarily expressed in the mitochondria of neuronal cells and is a crucial target for reducing ROS after SAH. rPrdx5 treatment may offer a promising therapeutic approach for clinical SAH patients.

A case of convexity non-aneurysmal subarachnoid hemorrhage caused by cerebral sinus thrombosis

BACKGROUND

Convexity subarachnoid hemorrhage (cSAH) is an uncommon presentation of subarachnoid bleeding, referring to bleeding more localized to the convexities of the brain. The diagnosis of cerebral venous sinus thrombosis (CVST) can be difficult especially when patients initially present with cSAH. The authors present a case and then discuss the pathophysiology and management.

CASE PRESENTATION

A 56-year-old woman with a previous history of hypertension and ischemic heart disease presented to the emergency department after experiencing it. Two seizures following a severe headache. The patient's history was negative for recent illnesses, head trauma, history of migraines, smoking, alcohol consumption, or intravenous drug use. The patient was diagnosed with CVST based on magnetic resonance venography (MRV). Genetic studies further identified homozygous mutations in the Prothrombin and MTHFR genes. Anticoagulant therapy was initiated with 60 mg of Enoxaparin twice daily and subsequently transitioned to Warfarin after 48 h continued for 3 months, and then replaced by rivaroxaban.

CONCLUSIONS

This study highlights the importance of considering CVST as a cause of SAH, emphasizes the role of advanced imaging in diagnosis, and demonstrates a successful treatment approach using both traditional and direct oral anticoagulants. The insights provided in this article can contribute to improving the management of patients with CVST-related SAH.