Subarachnoid Hemorrhage

Intracranial aneurysm wall (in)stability-current state of knowledge and clinical perspectives

Intracranial aneurysm (IA), a local outpouching of cerebral arteries, is present in 3 to 5% of the population. Once formed, an IA can remain stable, grow, or rupture. Determining the evolution of IAs is almost impossible. Rupture of an IA leads to subarachnoid hemorrhage and affects mostly young people with heavy consequences in terms of death, disabilities, and socioeconomic burden. Even if the large majority of IAs will never rupture, it is critical to determine which IA might be at risk of rupture. IA (in)stability is dependent on the composition of its wall and on its ability to repair. The biology of the IA wall is complex and not completely understood. Nowadays, the risk of rupture of an IA is estimated in clinics by using scores based on the characteristics of the IA itself and on the anamnesis of the patient. Classification and prediction using these scores are not satisfying and decisions whether a patient should be observed or treated need to be better informed by more reliable biomarkers. In the present review, the effects of known risk factors for rupture, as well as the effects of biomechanical forces on the IA wall composition, will be summarized. Moreover, recent advances in high-resolution vessel wall magnetic resonance imaging, which are promising tools to discriminate between stable and unstable IAs, will be described. Common data elements recently defined to improve IA disease knowledge and disease management will be presented. Finally, recent findings in genetics will be introduced and future directions in the field of IA will be exposed.

Angiotensin-(1-7) as a Potential Therapeutic Strategy for Delayed Cerebral Ischemia in Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a substantial cause of mortality and morbidity worldwide. Moreover, survivors after the initial bleeding are often subject to secondary brain injuries and delayed cerebral ischemia, further increasing the risk of a poor outcome. In recent years, the renin-angiotensin system (RAS) has been proposed as a target pathway for therapeutic interventions after brain injury. The RAS is a complex system of biochemical reactions critical for several systemic functions, namely, inflammation, vascular tone, endothelial activation, water balance, fibrosis, and apoptosis. The RAS system is classically divided into a pro-inflammatory axis, mediated by angiotensin (Ang)-II and its specific receptor AT₁R, and a counterbalancing system, presented in humans as Ang-(1-7) and its receptor, MasR. Experimental data suggest that upregulation of the Ang-(1-7)/MasR axis might be neuroprotective in numerous pathological conditions, namely, ischemic stroke, cognitive disorders, Parkinson's disease, and depression. In the presence of SAH, Ang-(1-7)/MasR neuroprotective and modulating properties could help reduce brain damage by acting on neuroinflammation, and through direct vascular and anti-thrombotic effects. Here we review the role of RAS in brain ischemia, with specific focus on SAH and the therapeutic potential of Ang-(1-7).

Post-traumatic intracranial pseudo-aneurysms of posterior circulation: a comprehensive review of an under-diagnosed and rare entity

Traumatic aneurysms are rare and the total number of cases involving the posterior circulation (TIPC) is even smaller. Traumatic brain injury (TBI) may be responsible not only of rupture in brain aneurysm (BrA) pre-existing to trauma, but it has been identified also as a possible pathogenetic cause of TIPC formation in patients not affected by intracranial vascular lesions. A complete literature review was performed of all reported cases regarding rupture of BrA with SAH resulting from TIPC not previously identified at the first radiological screening. A representative case of a left posterior inferior cerebellar artery (PICA) pseudo-aneurysm caused by left vertebral artery's dissection is reported. We show a unique complete collection of all 34 cases. Despite their rarity, TIPCs are associated with a significant morbidity and mortality rate, as high as 40-60%. Of the 22 patients with good neurological status (64.7%), we did not notice a significant correlation with regard to the location of the aneurysm, type of treatment, or clinical onset. Early recognition of a pseudo-aneurysm and adequate treatment seem to be the most important prognostic factor for these patients. Despite their rarity, TIPCs are associated with a significant morbidity and mortality rate. A TIPC should be suspected in case of delayed deterioration in head-injured patient and should be investigated with angiography. Conservative management is worsened by poor prognosis and the goal of treatment is to exclude the aneurysm from circulation with surgical or endovascular methods as soon as possible.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital with neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)-Part 1

BACKGROUND

Issues remain on the optimal management of subarachnoid hemorrhage (SAH) patients once they are admitted to the referring center, before and after the aneurysm treatment. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI). In this manuscript, we aim to provide a list of experts' recommendations regarding the early management of SAH patients from hospital admission, in a center with neurosurgical/neuro-endovascular facilities, until securing of the bleeding aneurysm.

METHODS

A multidisciplinary consensus panel composed of 24 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different background (anesthesia/intensive care, neurosurgery, and interventional neuroradiology) was created. A modified Delphi approach was adopted.

RESULTS

Among 19 statements discussed. The consensus was reached on 18 strong recommendations. In one case, consensus could not be agreed upon and no recommendation was provided.

CONCLUSIONS

This consensus provides practical recommendations for the management of SAH patients in hospitals with neurosurgical/neuroendovascular facilities until aneurysm securing. It is intended to support clinician's decision-making and not to mandate a standard of practice.

Endovascular Treatment of Patients with Ruptured Intracranial Aneurysms: A Series of 468 Patients Treated Over a 14-Year Period

Purpose:

Non-traumatic subarachnoid hemorrhage (SAH) is an emergency usually caused by the rupture of a saccular intracranial aneurysm. Endovascular treatment (EVT) is now considered as the first therapeutic option. The aim of our study is to evaluate, over a 14-year period in a single center, the result of EVT of ruptured intracranial aneurysms.

Methods:

From the retrospective analysis of our prospectively maintained database, we collected data of 457 patients successfully treated by endovascular approach for a SAH. Descriptive statistics and percentages were used to report clinical and anatomical outcomes, procedure-related complications, post procedural events, morbidity and mortality.

Results:

EVT was unsuccessful in eleven patients but effective in 457 patients with two patients who experienced a rebleeding (0.4%). In 6.3% of cases, a second EVT was necessary. The final aneurysm occlusion was complete (65.7%), with a neck remnant (28.2%) or incomplete (6.1%). Procedure-related complications occurred in 5.9% of patients and were associated with five clinical worsening and one death. Overall EVT-related morbidity and mortality were thus of 1.3% and 0.4% respectively. At discharge, 71% of patients had a good recovery (mRS 0–2), 11.2% had a poor outcome (mRS 3–5), and 17.8% died.

Conclusion:

This study seems to prove that high-volume centers with experienced interventional neuroradiologists carry low rates of technical failure and complication from EVT of ruptured intracranial aneurysm.

The Role of Soluble Urokinase Plasminogen Activator Receptor (suPAR) in the Context of Aneurysmal Subarachnoid Hemorrhage (aSAH)—A Prospective Observational Study

Objective

Outcome after aneurysmal subarachnoid hemorrhage (aSAH) is highly variable and largely determined by early brain injury and delayed cerebral ischemia (DCI). Soluble urokinase plasminogen activator receptor (suPAR) represents a promising inflammatory marker which has previously been associated with outcome in traumatic brain injury and stroke patients. However, its relevance in the context of inflammatory changes after aSAH is unclear. Here, we aimed to characterize the role of circulating suPAR in both serum and cerebrospinal fluid (CSF) as a novel biomarker for aSAH patients.

Methods

A total of 36 aSAH patients, 10 control patients with unruptured abdominal aneurysm and 32 healthy volunteers were included for analysis. suPAR was analyzed on the day of admission in all patients. In aSAH patients, suPAR was also determined on the day of DCI and the respective time frame in asymptomatic patients. One- and two-sample t-tests were used for simple difference comparisons within and between groups. Regression analysis was used to assess the influence of suPAR levels on outcome in terms of modified Rankin score.

Results

Significantly elevated suPAR serum levels (suPAR-SL) on admission were found for aSAH patients compared to healthy controls, but not compared to vascular control patients. Disease severity as documented according to Hunt and Hess grade and modified Fisher grade was associated with higher suPAR CSF levels (suPAR-CSFL). In aSAH patients, suPAR-SL increased daily by 4%, while suPAR-CSFL showed a significantly faster daily increase by an average of 22.5% per day. Each increase of the suPAR-SL by 1 ng/ml more than tripled the odds of developing DCI (OR = 3.06). While admission suPAR-CSFL was not predictive of DCI, we observed a significant correlation with modified Rankin's degree of disability at discharge.

Conclusion

Elevated suPAR serum level on admission as a biomarker for early inflammation after aSAH is associated with an increased risk of DCI. Elevated suPAR-CSFL levels correlate with a higher degree of disability at discharge. These distinct relations and the observation of a continuous increase over time affirm the role of inflammation in aSAH and require further study.

Basic Surveillance Parameters Improve the Prediction of Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Background

To establish a practical risk chart for prediction of delayed cerebral infarction (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) by using information that is available until day 5 after ictus.

Methods

We assessed all consecutive patients with aSAH admitted to our service between September 2008 and September 2015 (n = 417). The data set was randomly split into thirds. Two-thirds were used for model development and one-third was used for validation. Characteristics that were present between the bleeding event and day 5 (i.e., prior to >95% of DCI diagnoses) were assessed to predict DCI by using logistic regression models. A simple risk chart was established and validated.

Results

The amount of cisternal and ventricular blood on admission CT (Hijdra sum score), early sonographic vasospasm (i.e., mean flow velocity of either intracranial artery >160 cm/s until day 5), and a simplified binary level of consciousness score until day 5 were the strongest predictors of DCI. A model combining these predictors delivered a high predictive accuracy [the area under the receiver operating characteristic (AUC) curve of 0.82, Nagelkerke's R² 0.34 in the development cohort]. Validation of the model demonstrated a high discriminative capacity with the AUC of 0.82, Nagelkerke's R² 0.30 in the validation cohort.

Conclusion

Adding level of consciousness and sonographic vasospasm between admission and postbleed day 5 to the initial blood amount allows for simple and precise prediction of DCI. The suggested risk chart may prove useful for selection of appropriate candidates for interventions to prevent DCI.

Nimodipine Attenuates Early Brain Injury by Protecting the Glymphatic System After Subarachnoid Hemorrhage in Mice

The glymphatic system (GS) plays an important role in subarachnoid hemorrhage (SAH). Nimodipine treatment provides SAH patients with short-term neurological benefits. However, no trials have been conducted to quantify the relationship between nimodipine and GS. We hypothesized that nimodipine could attenuate early brain injury (EBI) after SAH by affecting the function of the GS. In this study, we assessed the effects of nimodipine, a dihydropyridine calcium channel antagonist, on mice 3 days after SAH. The functions of GS were assessed by immunofluorescence and western blot. The effects of nimodipine were assessed behaviorally. Concurrently, correlation analysis was performed for the functions of GS, immunofluorescence and behavioral function. Our results indicated that nimodipine improved GS function and attenuated neurological deficits and brain edema in mice with SAH. Activation of the cAMP/PKA pathway was involved in this process. GS function was closely associated with perivascular AQP4 polarization, cortical GFAP/AQP4 expression, brain edema and neurobehavioral function. In conclusion, this study shows for the first time that nimodipine plays a neuroprotective role in the period of EBI after SAH in mice through the GS.

A timeline of oligodendrocyte death and proliferation following experimental subarachnoid hemorrhage

AIMS

White matter (WM) injury is a critical factor associated with worse outcomes following subarachnoid hemorrhage (SAH). However, the detailed pathological changes are not completely understood. This study investigates temporal changes in the corpus callosum (CC), including WM edema and oligodendrocyte death after SAH, and the role of lipocalin-2 (LCN2) in those changes.

METHODS

Subarachnoid hemorrhage was induced in adult wild-type or LCN2 knockout mice via endovascular perforation. Magnetic resonance imaging was performed 4 hours, 1 day, and 8 days after SAH, and T2 hyperintensity changes within the CC were quantified to represent WM edema. Immunofluorescence staining was performed to evaluate oligodendrocyte death and proliferation.

RESULTS

Subarachnoid hemorrhage induced significant CC T2 hyperintensity at 4 hours and 1 day that diminished significantly by 8 days post-procedure. Comparing changes between the 4 hours and 1 day, each individual mouse had an increase in CC T2 hyperintensity volume. Oligodendrocyte death was observed at 4 hours, 1 day, and 8 days after SAH induction, and there was progressive loss of mature oligodendrocytes, while immature oligodendrocytes/oligodendrocyte precursor cells (OPCs) proliferated back to baseline by Day 8 after SAH. Moreover, LCN2 knockout attenuated WM edema and oligodendrocyte death at 24 hours after SAH.

CONCLUSIONS

Subarachnoid hemorrhage leads to T2 hyperintensity change within the CC, which indicates WM edema. Oligodendrocyte death was observed in the CC within 1 day of SAH, with a partial recovery by Day 8. SAH-induced WM injury was alleviated in an LCN2 knockout mouse model.

Potential Role of the Chemotaxis System in Formation and Progression of Intracranial Aneurysms Through Weighted Gene Co-Expression Network Analysis

Background

Intracranial aneurysm (IA) is the most common and is the main cause of spontaneous subarachnoid hemorrhage (SAH). The underlying molecular mechanisms for preventing IA progression have not been fully identified. Our research aimed to identify the key genes and critical pathways of IA through gene co-expression networks.

Methods

Gene Expression Omnibus (GEO) datasets GSE13353, GSE54083 and GSE75436 were used in the study. The genetic data were analyzed by weighted gene co-expression network analysis (WGCNA). Then the clinically significant modules were identified and the differentially expressed genes (DEGs) with the genes were intersected in these modules. GO (gene ontology) and KEGG (Kyoto Gene and Genomic Encyclopedia) were used for gene enrichment analysis to determine the function or pathway. In addition, the composition of immune cells was analyzed by CIBERSORT algorithm. Finally, the hub genes and key genes were identified by GSE122897.

Results

A total of 266 DEGs and two modules with clinical significance were identified. The inflammatory response and immune response were identified by GO and KEGG. CCR5, CCL4, CCL20, and FPR3 were the key genes in the module correlated with IA. The proportions of infiltrating immune cells in IA and normal tissues were different, especially in terms of macrophages and mast cells.

Conclusion

The chemotactic system has been identified as a key pathway of IA, and interacting macrophages may regulate this pathological process.

Inhibition of caspase-1-mediated inflammasome activation reduced blood coagulation in cerebrospinal fluid after subarachnoid haemorrhage

Background

Neuroinflammation and blood coagulation responses in cerebrospinal fluid (CSF) contribute to the poor outcome associated with subarachnoid haemorrhage (SAH). We explored the role of caspase-1-mediated inflammasome activation on extrinsic blood coagulation in CSF after SAH.

Methods

Post-SAH proteomic changes and correlation between caspase-1 with extrinsic coagulation factors in human CSF after SAH were analysed. Time course and cell localisation of brain inflammasome and extrinsic coagulation proteins after SAH were explored in a rat SAH model. Pharmacological inhibition of caspase-1 via VX-765 was used to explore the role of caspase-1 in blood clearance and CSF circulation after SAH in rats. Primary astrocytes were used to evaluate the role of caspase-1 in haemoglobin-induced pyroptosis and tissue factor (TF) production/release.

Findings

Neuroinflammation and blood coagulation activated after SAH in human CSF. The caspase-1 levels significantly correlated with the extrinsic coagulation factors. The activated caspase-1 and extrinsic coagulation initiator TF was increased on astrocytes after SAH in rats. VX-765 attenuated neurological deficits by accelerating CSF circulation and blood clearance through inhibiting pyroptotic neuroinflammation and TF-induced fibrin deposition in the short-term, and improved learning and memory capacity by preventing hippocampal neuronal loss and hydrocephalus in the long-term after SAH in rats. VX-765 reduced haemoglobin-induced pyroptosis and TF production/release in primary astrocytes.

Interpretation

Inhibition of caspase-1 by VX-765 appears to be a potential treatment against neuroinflammation and blood coagulation in CSF after SAH.

Funding

This study was supported by National Institutes of Health of United States of America, and National Natural Science Foundation of China.

Admission Lower Serum Phosphate Ion Levels Predict Acute Hydrocephalus of Aneurysmal Subarachnoid Hemorrhage

Introduction: The relationship between serum phosphate ion (sPi) and the occurrence of acute hydrocephalus (aHCP) in aneurysmal subarachnoid hemorrhage (aSAH) remains largely unknown and controversial. The primary aim of this study was to investigate the association between sPi on admission and aHCP following aSAH.

Methods: The study included 635 patients over the age of 19 years diagnosed with aSAH in our institution from September 2012 to June 2018. Data on clinical characteristics, laboratory parameters, treatments, and outcomes were collected and analyzed. The association between lower sPi levels and aHCP was assessed in univariate and multivariate analyses. Propensity-score matching (PSM) analysis was performed to reduce significant differences in baseline characteristics between the aHCP group and non-HCP group.

Results: The overall incidence of aHCP following aSAH was 19.37% (123/512). Lower sPi levels were detected in patients with aHCP compared with those without [0.86 (0.67–1.06) vs. 1.04 (0.84–1.21) mmol/L] in the univariate analysis. In the multivariate analysis, lower sPi level, high modified Fisher (mFisher) grade, and high Hunt-Hess grade were associated with aHCP [odds ratios (OR) 1.729, 95% confidence interval (CI) 1.139–2.623, p = 0.01; mFisher OR 0.097,95% CI 0.055–0.172, p < 0.001; Hunt-Hess, OR 0.555, 95% CI 0.320–0.961, P = 0.036]. After PSM, the matched aHCP group had a significantly lower sPi level than the matched non-aHCP group [0.86 (0.67–1.06) vs. 0.94 (0.76–1.12) mmol/L, p = 0.044]. The area under the curve (AUC) of the sPi level and the logistic regression model based on these predictors (sPi, Hunt-Hess grade, and mFisher grade) was 0.667 and 0.840 (sensitivity of 88.6% and specificity of 68.4%) for predicting aHCP, respectively.

Conclusions: Lower sPi levels predict the occurrence of aHCP, and the model constructed by sPi levels, Hunt-Hess grade, and mFisher grade markedly enhances the prediction of aHCP after aSAH.

Elevated Glucose-Potassium Ratio Predicts Preoperative Rebleeding in Patients With Aneurysmal Subarachnoid Hemorrhage

Introduction: Recent reports revealed that higher serum glucose-potassium ratio (GPR) levels at admission were significantly associated with poor outcomes at 3 months following aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to investigate the association between GPR and the risk of rebleeding following aSAH. Methods: This single-center retrospective study of patients with aSAH was conducted in our hospital between January 2008 and December 2020. Patients meeting the inclusion criteria were divided into the rebleed group and the non-rebleed group. Univariate and multivariate analyses were implemented to assess the association between risk factors of rebleeding and outcomes. Results: A total of 1,367 patients experiencing aSAH, 744 patients who met the entry criteria in the study [mean age (54.89 ± 11.30) years; 60.50% female patients], of whom 45 (6.05%) developed rebleeding. The patients in the rebleed group had significantly higher GPR levels than those of patients without rebleeding [2.13 (1.56-3.20) vs. 1.49 (1.23-1.87); p < 0.001]. Multivariable analysis revealed that higher mFisher grade and GPR were associated with rebleeding [mFisher grade, odds ratios (OR) 0.361, 95% CI 0.166-0.783, p = 0.01; GPR, OR 0.254, 95% CI 0.13-0.495, p < 0.001]. The receiver operating characteristics (ROCs) analysis described that the suitable cut-off value for GPR as a predictor for rebleeding in patients with aSAH was determined as 2.09 (the area under the curve [AUC] was 0.729, 95% CI 0.696-0.761, p < 0.0001; the sensitivity was 53.33%, and the specificity was 83.98%). Pearson correlation analysis showed a significant positive correlation between GPR and mFisher grade, between GPR and Hunt-Hess grade (mFisher grade r = 0.4271, OR 0.1824, 95% CI 0.3665-0.4842, p < 0.001; Hunt-Hess grade r = 0.4248, OR 0.1836, 95% CI 0.3697-0.4854, p < 0.001). The patients in the poor outcome had significantly higher GPR levels than those of patients in the good outcome [1.87 (1.53-2.42) vs. 1.45 (1.20-1.80); p < 0.001]. Multivariable analysis demonstrated that GPR was an independent predictor for poor prognosis. The AUC of GPR was 0.709 (95% CI 0.675-0.741; p < 0.0001) (sensitivity = 77.70%; specificity = 55.54%) for poor prognosis. Conclusion: Higher preoperative serum GPR level was associated with Hunt-Hess grade, mFisher grade, rebleeding, and unfunctional outcome, and that they predicted preoperative rebleeding and the 90-days outcome of non-diabetic patients with aSAH, who had potentially relevant clinical implications in patients with aSAH.

The Potential Role of Neuromodulation in Subarachnoid Hemorrhage

OBJECTIVES

Aneurysmal subarachnoid hemorrhage (SAH) continues to be a difficult cerebrovascular disease with limited pharmacologic treatment options. Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are leading causes of morbidity and mortality after SAH. Despite the advances in the understanding of its pathophysiology and tremendous efforts to date, nimodipine is currently the sole Food and Drug Administration-approved treatment for patients with SAH, with benefits that are marginal at best. The neuromodulation therapies are promising, especially those that target CV and DCI to improve functional outcomes. The aim of this review is therefore to summarize the available evidence for each type of neuromodulation for CV and DCI, with a special focus on its pathophysiological mechanisms, in addition to their clinical utility and drawbacks, which we hope will lead to future translational therapy options after SAH.

MATERIALS AND METHODS

We conducted a comprehensive review of preclinical and clinical studies demonstrating the use of neuromodulation for SAH. The literature search was performed using PubMed, Embase, and ClinicalTrials.gov. A total of 21 articles published from 1992 to 2021 and eight clinical trials were chosen.

RESULTS

The studies reviewed provide a compelling demonstration that neuromodulation is a potentially useful strategy to target multiple mechanisms of DCI and thus to potentially improve functional outcomes from SAH. There are several types of neuromodulation that have been tested to treat CV and DCI, including the trigeminal/vagus/facial nerve stimulation, sphenopalatine ganglion and spinal cord stimulation, transcranial direct electrical stimulation, transcutaneous electrical neurostimulation, and electroacupuncture. Most of them are in the preclinical or early phases of clinical application; however, they show promising results.

CONCLUSIONS

DCI has a complex pathogenesis, making the unique anatomical distribution and pleiotropic capabilities of various types of neuromodulation a promising field of study. We may be at the cusp of a breakthrough in the use of these techniques for the treatment of this stubbornly difficult disease.

COG133 Attenuates the Early Brain Injury Induced by Blood-Brain Barrier Disruption in Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a kind of severe hemorrhagic stroke, and early brain injury acted as one of the main causes of death and delayed neurological deficit in patients with subarachnoid hemorrhage. In this process, the function and structural integrity of the blood-brain barrier play an important role. In this study, we have observed whether the apolipoprotein E (apoE) mimetic peptide, COG133, can alleviate early brain injury after subarachnoid hemorrhage. For this purpose, an experimental subarachnoid hemorrhage model was constructed in mice and treated by intravenous injection of COG133 at a dosage of 1 mg/kg. Then, the function and integrity of the blood-brain barrier were detected, and the pyroptosis level of the neuron was determined. The results showed that COG133 could protect blood-brain barrier function and structure integrity, reduce early brain injury, and ameliorate neurological function after subarachnoid hemorrhage. In terms of molecular mechanism, COG133 inhibits blood-brain barrier destruction through the proinflammatory CypA-NF-κB-MMP9 pathway and reduces neuronal pyroptosis by inhibiting NLRP3 inflammasome activation. In conclusion, this study demonstrated that apoE-mimetic peptide, COG133, can play a neuroprotective role by protecting blood-brain barrier function and inhibiting brain cell pyroptosis to reduce early brain injury after subarachnoid hemorrhage.

Effect of Aneurysm and Patient Characteristics on Intracranial Aneurysm Wall Thickness

Background: The circle of Willis is a network of arteries allowing blood supply to the brain. Bulging of these arteries leads to formation of intracranial aneurysm (IA). Subarachnoid hemorrhage (SAH) due to IA rupture is among the leading causes of disability in the western world. The formation and rupture of IAs is a complex pathological process not completely understood. In the present study, we have precisely measured aneurysmal wall thickness and its uniformity on histological sections and investigated for associations between IA wall thickness/uniformity and commonly admitted risk factors for IA rupture.

Methods: Fifty-five aneurysm domes were obtained at the Geneva University Hospitals during microsurgery after clipping of the IA neck. Samples were embedded in paraffin, sectioned and stained with hematoxylin-eosin to measure IA wall thickness. The mean, minimum, and maximum wall thickness as well as thickness uniformity was measured for each IA. Clinical data related to IA characteristics (ruptured or unruptured, vascular location, maximum dome diameter, neck size, bottleneck factor, aspect and morphology), and patient characteristics [age, smoking, hypertension, sex, ethnicity, previous SAH, positive family history for IA/SAH, presence of multiple IAs and diagnosis of polycystic kidney disease (PKD)] were collected.

Results: We found positive correlations between maximum dome diameter or neck size and IA wall thickness and thickness uniformity. PKD patients had thinner IA walls. No associations were found between smoking, hypertension, sex, IA multiplicity, rupture status or vascular location, and IA wall thickness. No correlation was found between patient age and IA wall thickness. The group of IAs with non-uniform wall thickness contained more ruptured IAs, women and patients harboring multiple IAs. Finally, PHASES and ELAPSS scores were positively correlated with higher IA wall heterogeneity.

Conclusion: Among our patient and aneurysm characteristics of interest, maximum dome diameter, neck size and PKD were the three factors having the most significant impact on IA wall thickness and thickness uniformity. Moreover, wall thickness heterogeneity was more observed in ruptured IAs, in women and in patients with multiple IAs. Advanced medical imaging allowing in vivo measurement of IA wall thickness would certainly improve personalized management of the disease and patient care.

Impact of deep learning reconstruction on intracranial 1.5 T magnetic resonance angiography

Purpose

The purpose of this study was to evaluate whether deep learning reconstruction (DLR) improves the image quality of intracranial magnetic resonance angiography (MRA) at 1.5 T.

Materials and methods

In this retrospective study, MRA images of 40 patients (21 males and 19 females; mean age, 65.8 ± 13.2 years) were reconstructed with and without the DLR technique (DLR image and non-DLR image, respectively). Quantitative image analysis was performed by placing regions of interest on the basilar artery and cerebrospinal fluid in the prepontine cistern. We calculated the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for analyses of the basilar artery. Two experienced radiologists evaluated the depiction of structures (the right internal carotid artery, right ophthalmic artery, basilar artery, and right superior cerebellar artery), artifacts, subjective noise and overall image quality in a qualitative image analysis. Scores were compared in the quantitative and qualitative image analyses between the DLR and non-DLR images using Wilcoxon signed-rank tests.

Results

The SNR and CNR for the basilar artery were significantly higher for the DLR images than for the non-DLR images (p < 0.001). Qualitative image analysis scores (p < 0.003 and p < 0.005 for readers 1 and 2, respectively), excluding those for artifacts (p = 0.072–0.565), were also significantly higher for the DLR images than for the non-DLR images.

Conclusion

DLR enables the production of higher quality 1.5 T intracranial MRA images with improved visualization of arteries.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital without neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)

Background

The immediate management of subarachnoid hemorrhage (SAH) patients in hospitals without neurosurgical/neurointerventional facilities and their transfer to a specialized center is challenging and not well covered in existing guidelines. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI) to provide clinical guidance.

Methods

A multidisciplinary consensus panel composed by 19 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different specializations (anesthesia/intensive care, neurosurgery and interventional neuroradiology) was created. A modified Delphi approach was adopted.

Results

A total of 14 statements have been discussed. Consensus was reached on 11 strong recommendations and 2 weak recommendations. In one case, where consensus could not be agreed upon, no recommendation could be provided.

Conclusions

Management of SAH in a non-specialized setting and early transfer are difficult and may have a critical impact on outcome. Clinical advice, based on multidisciplinary consensus, might be helpful. Our recommendations cover most, but not all, topics of clinical relevance.

Cost-effectiveness analysis in patients with an unruptured cerebral aneurysm treated with observation or surgery

OBJECTIVE

The main goal of preventive treatment of unruptured intracranial aneurysms (UIAs) is to avoid the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage. A comparison between the conservative approach and the surgical approach combining endovascular treatment and microsurgical clipping is currently lacking. This study aimed to conduct an updated evaluation of cost-effectiveness comparing the two approaches in patients with UIA.

METHODS

A decision tree with a Markov model was developed. Quality-adjusted life-years (QALYs) associated with living with UIA before and after treatment were prospectively collected from a cohort of patients with UIA at a tertiary center. Other inputs were obtained from published literature. Using Monte Carlo simulation for patients aged 55, 65, and 75 years, the authors modeled the conservative management in comparison with preventive treatment. Different proportions of endovascular and microsurgical treatment were modeled to reflect existing practice variations between treatment centers. Outcomes were assessed in terms of QALYs. Sensitivity analyses to assess the model's robustness and completed threshold analyses to examine the influence of input parameters were performed.

RESULTS

Preventive treatment of UIAs consistently led to higher utility. Models using a higher proportion of endovascular therapy were more cost-effective. Models with older cohorts were less cost-effective than those with younger cohorts. Treatment was cost-effective (willingness to pay < 100,000 USD/QALY) if the annual rupture risk exceeded a threshold between 0.8% and 1.9% in various models based on the proportion of endovascular treatment and cohort age. A higher proportion of endovascular treatments and younger age lowered this threshold, making the treatment of aneurysms with a lower risk of rupture more cost-effective.

CONCLUSIONS

Preventive treatment of aneurysms led to higher utility compared with conservative management. Models with a higher proportion of endovascular treatment and younger patient age were most cost-effective.

SERS-based immunoassay based on gold nanostars modified with 5,5'-dithiobis-2-nitrobenzoic acid for determination of glial fibrillary acidic protein

A surface-enhanced Raman scattering (SERS)-based immunoassay with gold nanostars (GNSs) is utilized for determination of the subarachnoid hemorrhage (SAH) biomarker glial fibrillary acidic protein (GFAP) at very low concentration levels, which allows for early diagnosis and guides clinical decision-making to treat SAH-induced complications. The Raman reporter 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) modified on GNSs was selected as the SERS tags. The SERS immunoassay was assembled by SERS tag and GFAP probe-immobilized ITO substrate. Therefore, the level of GFAP can be detected by monitoring the characteristic Raman peak intensity of GFAP-conjugated GNSs at 1332 cm^-1 with a very low detection limit. Under optimized conditions, the assay can work in the GFAP concentration range from 1 pg⋅mL^-1 to 1 μg⋅mL^-1, with a detection limit as low as 0.54 fg⋅mL^-1. The performance of the SERS immunoassay proven by the detection of GFAP is equivalent to that of the conventional enzyme-linked immunosorbent assay (ELISA). Scheme 1. Schematic illustration of GNSs SERS immunoassay for ultrasensitive dynamic change detection of GFAP. (SAH: Subarachnoid hemorrhage, SCF: Cerebrospinal fluid; GNSs: gold nanostars; SERS: surface-enhanced Raman scattering; GFAP: glial fibrillary acidic protein).

Modifiable Risk Factors for Intracranial Aneurysm and Aneurysmal Subarachnoid Hemorrhage: A Mendelian Randomization Study

Background

The aim of this study was to assess the associations of modifiable lifestyle factors (smoking, coffee consumption, sleep, and physical activity) and cardiometabolic factors (body mass index, glycemic traits, type 2 diabetes, systolic and diastolic blood pressure, lipids, and inflammation and kidney function markers) with risks of any (ruptured or unruptured) intracranial aneurysm and aneurysmal subarachnoid hemorrhage using Mendelian randomization.

Methods and Results

Summary statistical data for the genetic associations with the modifiable risk factors and the outcomes were obtained from meta‐analyses of genome‐wide association studies. The inverse‐variance weighted method was used as the main Mendelian randomization analysis, with additional sensitivity analyses conducted using methods more robust to horizontal pleiotropy. Genetic predisposition to smoking, insomnia, and higher blood pressure was associated with an increased risk of both intracranial aneurysm and aneurysmal subarachnoid hemorrhage. For intracranial aneurysm, the odds ratios were 3.20 (95% CI, 1.93–5.29) per SD increase in smoking index, 1.24 (95% CI, 1.10–1.40) per unit increase in log‐odds of insomnia, and 2.92 (95% CI, 2.49–3.43) per 10 mm Hg increase in diastolic blood pressure. In addition, there was weak evidence for associations of genetically predicted decreased physical activity, higher triglyceride levels, higher body mass index, and lower low‐density lipoprotein cholesterol levels with higher risk of intracranial aneurysm and aneurysmal subarachnoid hemorrhage, with 95% CI overlapping the null for at least 1 of the outcomes. All results were consistent in sensitivity analyses.

Conclusions

This Mendelian randomization study suggests that smoking, insomnia, and high blood pressure are major risk factors for intracranial aneurysm and aneurysmal subarachnoid hemorrhage.

Melatonin and risk of mortality in subjects with aneurysmal subarachnoid hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is a cause of morbidity associated with aneurysmal subarachnoid hemorrhage (aSAH). Neuroinflammation contributes to the development of DCI. Melatonin is a sleep-promoting hormone known to have cerebral anti-inflammatory properties. We hypothesized that synthetic melatonin (or the selective melatonin receptor agonist ramelteon) incidentally prescribed to improve sleep may lower the incidence of DCI among hospitalized aSAH patients.

METHODS

Subjects with a Hunt and Hess Grade I-III were identified from a data registry involving all aSAH patients admitted to our hospital between January 2015 and September 1, 2018. A cohort of patients who received either melatonin or ramelteon during their hospitalization was compared to a matched cohort that did not receive these drugs. The primary endpoint was incidence of DCI. Secondary outcomes included modified Rankin score (mRS) at discharge, discharge destination, and mortality at 6 weeks from discharge. The two groups were compared using univariate analysis. P < 0.05 was considered significant.

RESULTS

There was no significant difference in the incidence of DCI (15.8% vs. 16.9%, p = 1), discharge mRS (mRS 0-3: 51.3% vs. 45.1%, p = 0.59), discharge disposition (Home: 43.6% vs. 44.4, p = 0.47), or mortality (0% vs. 9.2%; p = 0.074) between the melatonin/ramelteon and non-melatonin groups.

CONCLUSION

The use melatonin had no effect on DCI but may improve mortality in aSAH subjects. Prospective studies using a larger cohort are warranted to validate these findings.

Effects of Low and High Aneurysmal Wall Shear Stress on Endothelial Cell Behavior: Differences and Similarities

Background: Intracranial aneurysms (IAs) result from abnormal enlargement of the arterial lumen. IAs are mostly quiescent and asymptomatic, but their rupture leads to severe brain damage or death. As the evolution of IAs is hard to predict and intricates medical decision, it is essential to improve our understanding of their pathophysiology. Wall shear stress (WSS) is proposed to influence IA growth and rupture. In this study, we investigated the effects of low and supra-high aneurysmal WSS on endothelial cells (ECs).

Methods: Porcine arterial ECs were exposed for 48 h to defined levels of shear stress (2, 30, or 80 dyne/cm²) using an Ibidi flow apparatus. Immunostaining for CD31 or γ-cytoplasmic actin was performed to outline cell borders or to determine cell architecture. Geometry measurements (cell orientation, area, circularity and aspect ratio) were performed on confocal microscopy images. mRNA was extracted for RNAseq analysis.

Results: ECs exposed to low or supra-high aneurysmal WSS were more circular and had a lower aspect ratio than cells exposed to physiological flow. Furthermore, they lost the alignment in the direction of flow observed under physiological conditions. The effects of low WSS on differential gene expression were stronger than those of supra-high WSS. Gene set enrichment analysis highlighted that extracellular matrix proteins, cytoskeletal proteins and more particularly the actin protein family were among the protein classes the most affected by shear stress. Interestingly, most genes showed an opposite regulation under both types of aneurysmal WSS. Immunostainings for γ-cytoplasmic actin suggested a different organization of this cytoskeletal protein between ECs exposed to physiological and both types of aneurysmal WSS.

Conclusion: Under both aneurysmal low and supra-high WSS the typical arterial EC morphology molds to a more spherical shape. Whereas low WSS down-regulates the expression of cytoskeletal-related proteins and up-regulates extracellular matrix proteins, supra-high WSS induces opposite changes in gene expression of these protein classes. The differential regulation in EC gene expression observed under various WSS translate into a different organization of the ECs’ architecture. This adaptation of ECs to different aneurysmal WSS conditions may affect vascular remodeling in IAs.

Influence of nimodipine combined with ulinastatin on neurological function and inflammatory reaction in patients with cerebral vasospasm after subarachnoid hemorrhage

OBJECTIVE

This study aimed to discuss the influence of nimodipine+ulinastatin on the neurological function and inflammatory reaction in patients with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH).

METHODS

Overall, 90 patients with CVS after SAH who were admitted to our hospital were enrolled in this study and randomly divided into research and control groups (n = 45 for both groups). On the basis of conventional therapy, patients in the control group were injected with ulinastatin and those in the research group were injected with ulinastatin+nimodipine through an intravenous drip for 7 days with the others the same as those of the control group.

RESULTS

Blood flow velocity in all cerebral arteries was lower in the research group than in the control group after treatment (P < 0.05). Calcitonin gene-related peptide and nitric oxide levels were higher in the research group than in the control group after treatment (P < 0.05). Endothelin levels were lower in the research group than in the control group (P < 0.05). The total effective rate was higher in the research group than in the control group (P < 0.05). Glasgow Coma Scale scores were higher in the research group than in the control group (P < 0.05).

CONCLUSION

The drug combination of nimodipine and ulinastatin improved blood flow and neurological function in patients with CVS after SAH and enhanced the therapeutic efficacy; the underlying mechanism may be associated with the regulation of vascular endothelial dilatation function and the inhibition of relevant inflammatory factors' expression.

Adrenocorticotropic hormone and β-endorphin concentration as a prognostic factor in patients with subarachnoid hemorrhage due to aneurysmal rupture

Objective

Adrenocorticotropic hormone (ACTH) and β-endorphin are pituitary neuro-peptides released by acute stress. We determined why the prognosis of patients with subarachnoid hemorrhages (SAH) due to aneurysmal rupture is not always dependent on the Hunt–Hess grading system (HHS) and delta-National Institutes of Health Stroke Scale (NIHSS), while studying endogenous neuropeptides, including ACTH and β-endorphin.

Methods

We analyzed blood samples collected from patients with SAH (SAH group; n=37) and those with unruptured intracranial aneurysms (control group; n=37). Blood sampling was performed before any procedure or chemical agents administration. The results of ACTH and β-endorphin measurements were compared using the delta-NIHSS and HHS. The data were analyzed using descriptive statistics, independent samples t-tests, and Pearson’s correlations.

Results

Of the 18 patients with low-grade HHS, 13 had low delta-NIHSS and five showed high delta-NIHSS. Of the 19 patients with high-grade HHS, the delta-NIHSS was ≥14 in the other five patients. ACTH concentration was high (497.3 pg/mL) in five patients with high-grade HHS and high delta-NIHSS. β-endorphin concentration was high (159.7 pg/mL) in 13 patients with low-grade HHS and low delta-NIHSS.

Conclusions

High ACTH levels in patients with massive bleeding and poor neurological status suggests increasing ACTH secretion in response to bleeding stress, which may aggravate neurological status. Contrary to ACTH, high β-endorphin levels in patients with low-grade HHS implied the involvement of additional factors in predicting fair outcomes related to low delta-NIHSS. These results may provide insight into the varying prognostic potential of HHS in SAH patients.

RNase A Inhibits Formation of Neutrophil Extracellular Traps in Subarachnoid Hemorrhage

Background: Subarachnoid hemorrhage (SAH) caused by rupture of an intracranial aneurysm, is a life-threatening emergency that is associated with substantial morbidity and mortality. Emerging evidence suggests involvement of the innate immune response in secondary brain injury, and a potential role of neutrophil extracellular traps (NETs) for SAH-associated neuroinflammation. In this study, we investigated the spatiotemporal patterns of NETs in SAH and the potential role of the RNase A (the bovine equivalent to human RNase 1) application on NET burden. Methods: A total number of n=81 male C57Bl/6 mice were operated utilizing a filament perforation model to induce SAH, and Sham operation was performed for the corresponding control groups. To confirm the bleeding and exclude stroke and intracerebral hemorrhage, the animals received MRI after 24h. Mice were treated with intravenous injection of RNase A (42μg/kg body weight) or saline solution for the control groups, respectively. Quadruple-immunofluorescence (IF) staining for cell nuclei (DAPI), F-actin (phalloidin), citrullinated H3, and neurons (NeuN) was analyzed by confocal imaging and used to quantify NET abundance in the subarachnoid space (SAS) and brain parenchyma. To quantify NETs in human SAH patients, cerebrospinal spinal fluid (CSF) and blood samples from day 1, 2, 7, and 14 after bleeding onset were analyzed for double-stranded DNA (dsDNA) via Sytox Green. Results: Neutrophil extracellular traps are released upon subarachnoid hemorrhage in the SAS on the ipsilateral bleeding site 24h after ictus. Over time, NETs showed progressive increase in the parenchyma on both ipsi- and contralateral site, peaking on day 14 in periventricular localization. In CSF and blood samples of patients with aneurysmal SAH, NETs also increased gradually over time with a peak on day 7. RNase application significantly reduced NET accumulation in basal, cortical, and periventricular areas. Conclusion: Neutrophil extracellular trap formation following SAH originates in the ipsilateral SAS of the bleeding site and spreads gradually over time to basal, cortical, and periventricular areas in the parenchyma within 14days. Intravenous RNase application abrogates NET burden significantly in the brain parenchyma, underpinning a potential role in modulation of the innate immune activation after SAH.

Feasibility of robot-assisted neuroendovascular procedures

OBJECTIVE

Geographic factors prevent equitable access to urgent advanced neuroendovascular treatments. Robotic technologies may enable remote endovascular procedures in the future. The authors performed a translational, benchtop-to-clinical study to evaluate the in vitro and clinical feasibility of the CorPath GRX Robotic System for robot-assisted endovascular neurointerventional procedures.

METHODS

A series of bench studies was conducted using patient-specific 3D-printed models to test the system's compatibility with standard neurointerventional devices, including microcatheters, microwires, coils, intrasaccular devices, and stents. Optimal baseline setups for various procedures were determined. The models were further used to rehearse clinical cases. Subsequent to these investigations, a prospective series of 6 patients was treated using robotic assistance for complex, wide-necked intracranial saccular aneurysms between November 2019 and February 2020. The technical success, incidence of periprocedural complications, and need for conversion to manual procedures were evaluated.

RESULTS

The ideal robotic setup for treatment of both anterior and posterior circulation aneurysms was determined to consist of an 80-cm guide catheter with a 115-cm-long intermediate catheter, a microcatheter between 150 and 170 cm in length, and a microwire with a minimum length of 300 cm. All coils, intrasaccular devices, and stents tested were compatible with the system and could be advanced or retracted safely and placed accurately. All 6 clinical procedures were technically successful, with all intracranial steps being performed robotically with no conversions to manual intervention or failures of the robotic system. There were no procedure-related complications or adverse clinical outcomes.

CONCLUSIONS

This study demonstrates the feasibility of robot-assisted neurointerventional procedures. The authors' results represent an important step toward enabling remote neuroendovascular care and geographic equalization of advanced endovascular treatments through so-called telestroke intervention.

Icariin, an Up-and-Coming Bioactive Compound Against Neurological Diseases: Network Pharmacology-Based Study and Literature Review

Icariin is a biologically active substance in Epimedii herba that is used for the treatment of neurologic disorders. However, a comprehensive analysis of the molecular mechanisms of icariin is lacking. In this review, we present a brief history of the use of icariin for medicinal purposes; describe the active chemical components of Epimedii herba; and examine the evidence from experimental studies that have uncovered molecular targets of icariin in different diseases. We also constructed a protein–protein interaction network and carried out Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analyses to predict the therapeutic actions of icariin in nervous system diseases including Alzheimer disease, Parkinson disease, ischemic stroke, depressive disorder, multiple sclerosis, glioblastoma, and hereditary spastic paraplegias. The results of our analyses can guide future studies on the application of icariin to the treatment of neurologic disorders.

Impact of the 'weekend effect' on hospital-acquired pneumonia after aneurysmal subarachnoid hemorrhage

OBJECTIVES

Weekend admission has been reported to be associated with poor clinical outcomes of various diseases. This study aimed to determine whether weekend admission increases the incidence of hospital-acquired pneumonia (HAP) in patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

We retrospectively analyzed aSAH patients admitted to our hospital between 2014 and 2020. These patients were divided into weekend and weekday groups. We compared the incidence of HAP and other clinical outcomes between the two groups. Risk factors for HAP were identified by logistic regression analysis.

RESULTS

Of 653 included aSAH patients, 145 (22%) were admitted on weekends and 508 (78%) were admitted on weekdays. The incidence of HAP in the weekend group was significantly higher than that in the weekday group (25% vs 16%, P = 0.01). The weekend group showed worse clinical outcomes, including worse neurological outcome (74% vs 65%, P = 0.03), higher risk of intensive care unit (ICU) admission (21% vs 13%, P = 0.01) and longer length of stay (21.3 vs 16.4 days, P < 0.01). Age ≥ 60 years (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.3-3.0, P < 0.01), modified Fisher score (MFS) ≥ 3 (OR = 1.7, 95% CI = 1.1-2.6, P = 0.02), weekend admission (OR = 1.8, 95% CI = 1.1-2.8, P = 0.02) and operative treatment (OR = 2.3, 95% CI = 1.2-4.5, P = 0.02) were risk factors for HAP following aSAH.

CONCLUSION

Weekend admission was associated with a higher incidence of HAP in aSAH patients. This study suggested that medical administrators may need to optimize healthcare services on weekends.

Quantitative Modeling of External Ventricular Drain Output to Predict Shunt Dependency in Aneurysmal Subarachnoid Hemorrhage: Cohort Study

BACKGROUND

Acute hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH); however, attempts to predict shunt-dependent chronic hydrocephalus using clinical parameters have been equivocal.

METHODS

Cohort study of aSAH is treated with external ventricular drainage (EVD) placement at our institution, 2001-2016, via logistic regression. EVD-related parameters included mean/total EVD output (days 0-2), EVD days, EVD days ≤ 5 mmHg, and wean/clamp fails. aSAH outcomes assessed included ventriculoperitoneal shunt (VPS) placement, delayed cerebral ischemia (DCI), radiographic infarction (RI), symptomatic vasospasm (SV), age, and aSAH grades.

RESULTS

Two hundred and ten aSAH patients underwent EVD treatment for a median 12 days (range 1-54); 85 required VPS (40%). On univariate analysis, EVD output, total EVD days, EVD days ≤ 5 mmHg, and wean/clamp trial failures were significantly associated with VPS placement (p < 0.01 for all parameters). No EVD output parameter demonstrated a significant association with DCI, RI, or SV. On multivariate analysis, EVD output was a significant predictor of VPS placement, after adjusting for age and clinical and radiological grades; the optimal threshold for predicting VPS placement was mean daily output > 204 ml on days 0-2 (OR 2.59, 95% CI 1.31-5.07). Multiple wean failures were associated with unfavorable functional outcome, after adjusting for age, grade, and VPS placement (OR 1.65, 95% CI 1.10-2.47). We developed a score incorporating age, grade and EVD parameters (MAGE) for predicting VPS placement after aSAH.

CONCLUSIONS

EVD output parameters and wean/clamp trial failures predicted shunt dependence in an age- and grade-adjusted multivariable model. Early VPS placement may be warranted in patients with MAGE score ≥ 4, particularly following 2 failed wean trials.

Clinical characteristics and factors relating to poor outcome in patients with aneurysmal subarachnoid hemorrhage in Vietnam: A multicenter prospective cohort study

BACKGROUND

The prevalence of risk factors for poor outcomes from aneurysmal subarachnoid hemorrhage (SAH) varies widely and has not been fully elucidated to date in Vietnam. Understanding the risk and prognosis of aneurysmal SAH is important to reduce poor outcomes in Vietnam. The aim of this study, therefore, was to investigate the rate of poor outcome at 90 days of ictus and associated factors from aneurysmal SAH in the country.

METHODS

We performed a multicenter prospective cohort study of patients (≥18 years) presenting with aneurysmal SAH to three central hospitals in Hanoi, Vietnam, from August 2019 to August 2020. We collected data on the characteristics, management, and outcomes of patients with aneurysmal SAH and compared these data between good (defined as modified Rankin Scale (mRS) of 0 to 3) and poor (mRS, 4-6) outcomes at 90 days of ictus. We assessed factors associated with poor outcomes using logistic regression analysis.

RESULTS

Of 168 patients with aneurysmal SAH, 77/168 (45.8%) were men, and the median age was 57 years (IQR: 48-67). Up to 57/168 (33.9%) of these patients had poor outcomes at 90 days of ictus. Most patients underwent sudden-onset and severe headache (87.5%; 147/168) and were transferred from local to participating central hospitals (80.4%, 135/168), over half (57.1%, 92/161) of whom arrived in central hospitals after 24 hours of ictus, and the initial median World Federation of Neurological Surgeons (WFNS) grading score was 2 (IQR: 1-4). Nearly half of the patients (47.0%; 79/168) were treated with endovascular coiling, 37.5% (63/168) were treated with surgical clipping, the remaining patients (15.5%; 26/168) did not receive aneurysm repair, and late rebleeding and delayed cerebral ischemia (DCI) occurred in 6.1% (10/164) and 10.4% (17/163) of patients, respectively. An initial WFNS grade of IV (odds ratio, OR: 15.285; 95% confidence interval, CI: 3.096-75.466) and a grade of V (OR: 162.965; 95% CI: 9.975-2662.318) were independently associated with poor outcomes. Additionally, both endovascular coiling (OR: 0.033; 95% CI: 0.005-0.235) and surgical clipping (OR: 0.046; 95% CI: 0.006-0.370) were inversely and independently associated with poor outcome. Late rebleeding (OR: 97.624; 95% CI: 5.653-1686.010) and DCI (OR: 15.209; 95% CI: 2.321-99.673) were also independently associated with poor outcome.

CONCLUSIONS

Improvements are needed in the management of aneurysmal SAH in Vietnam, such as increasing the number of aneurysm repairs, performing earlier aneurysm treatment by surgical clipping or endovascular coiling, and improving both aneurysm repairs and neurocritical care.

Quality of life scores in patients with unruptured cerebral aneurysm: Prospective cohort study

BACKGROUND

Living with the diagnosis of an unruptured cerebral aneurysm can understandably cause distress to a patient. The goal of preventive treatment is to increase the number of years with good quality of life (QoL).

OBJECTIVE

This study aimed to measure the effect of unruptured intracranial aneurysm treatment on change in QoL scores measured by the SF36 and EQ-5D-5L.

METHODS

We prospectively collected SF36 and EQ-5D-5L survey data for patients with unruptured intracranial aneurysms at two time-points over 1 year between 2 treatment groups: observation and intervention (microsurgical and endovascular). Multivariable linear regression was used to examine treatment group differences in the mean change in scores from baseline to 1 year when adjusted for covariates.

RESULTS

92 patients were included in the observation group and 68 patients were included in the intervention group, for a total of 160 patients. The intervention group had lower SF36 total scores at baseline (p = 0.001). With multivariate linear regression models, the effect of treatment on mean change in SF36 total score from baseline to 1 year was not statistically significant (p = 0.4); similarly, there was no difference in mean change in EQ-5D-5L.

CONCLUSION

In this large prospective study, preventive aneurysm treatment was not associated with a significant change in QoL score at 1 year compared to observation as measured by the SF36 and EQ-5D-5L. Further studies are needed to explore the lower QoL scores in patients seeking treatment and its impact on management decision making.

Subarachnoid Hemorrhage Early Brain Edema Score (SEBES) as a radiographic marker of clinically relevant intracranial hypertension and unfavorable outcome after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The severity of early brain edema (EBE) after aneurysm rupture was reported to be strongly associated with the risk of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Using the recently developed Subarachnoid Hemorrhage Early Brain Edema Score (SEBES), we analyzed the predictors of EBE and its impact on complications related to intracranial pressure (ICP) increase after SAH and on poor outcome.

METHODS

All consecutive SAH cases treated between January 2003 and June 2016 with assessable SEBES were included (n = 745). Data on demographic characteristics, medical history, initial severity of SAH, need for conservative ICP treatment and decompressive craniectomy, occurrence of cerebral infarctions and unfavorable outcome at 6 months (modified Rankin scale score > 2) were collected. Univariable and multivariable analyses were performed.

RESULTS

Younger age (<55 years; adjusted odds ratio [aOR] 3.16, 95% confidence interval [CI] 2.28-4.38), female sex (aOR 1.64, 95% CI 1.16-2.31), poor initial clinical condition (World Federation of Neurosurgical Societies score 4-5; aOR 1.74, 95% CI 1.23-2.46), presence of intracerebral hemorrhage (aOR 1.63, 95% CI 1.12-2.36), hypothyroidism (aOR 0.60, 95% CI 0.37-0.98) and renal comorbidity (aOR 0.29, 95% CI 0.11-0.78) were independently associated with SEBES (scores 3-4). There was an independent association between SEBES 3-4 and the need for conservative ICP treatment (aOR 2.43, 95% CI 1.73-3.42), decompressive craniectomy (aOR 2.68, 95% CI 1.84-3.89), development of cerebral infarcts (aOR 2.24, 95% CI 1.53-3.29) and unfavorable outcome (aOR 1.48, 95% CI 1.0-2.17).

CONCLUSIONS

SEBES is a reliable predictor of ICP-related complications and poor outcome of SAH. Our findings highlight the need for further research of the impact of patients' demographic characteristics and comorbidities on the severity of EBE after SAH.

Kinetics of cerebral blood flow velocities during treatment for delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage

BACKGROUND

In aneurysmal subarachnoid hemorrhage (aSAH), one of the main determinants of prognosis is delayed cerebral ischemia (DCI). Transcranial Doppler (TCD) is used to monitor vasospasm and DCI. We aimed to better understand cerebral hemodynamics response to hypertension induction (HI) with norepinephrine (NE) and inotropic therapy with milrinone so that TCD can be a bedside tool in helping to guide DCI therapies. Our primary objective was to determine TCD blood flow velocity (BFV) kinetics during HI and inotropic therapy for DCI treatment. Secondly, we performed an analysis by treatment subgroups and evaluated clinical response to therapies.

METHODS

We performed a prospective observational cohort study in a Brazilian high-volume center for aSAH. Patients with aSAH admitted between 2016 and 2018 who received NE or milrinone for DCI treatment were included. TCDs were performed before therapy initiation (t0) and 45 (t1) and 90 min (t2) from the onset of therapy. For each DCI event, we analyzed the highest mean flow velocity (MFV) and the mean MFV and compared their kinetics over time. The National Institutes of Health Stroke Scale was determined at t0, t1, and t2.

RESULTS

Ninety-eight patients with aSAH were admitted during the study period. Twenty-one (21.4%) developed DCI, of whom six had DCI twice, leading to a total of 27 analyzed DCI events (12 treated with HI and 15 with milrinone). Patients treated with NE had their mean arterial pressure raised (85 mm Hg in t0, 112 mm Hg in t2 [p < 0.001]), whereas those treated with milrinone had a significant decrease in mean arterial pressure over treatment (94 mm Hg in t0, 88 mm Hg in t2 [p = 0.004]). Among all treated patients, there was a significant drop from t0 to t2 but not to t1 in the highest MFV and in the highest mean MFV. Among those treated with HI, there were no significant changes from t0 to t1 or t2 (highest MFV in t0 163.2 cm/s, in t1 172.9 cm/s [p = 0.27], and in t2 164 cm/s [p = 0.936]). Conversely, in those treated with milrinone, there was a significant decrease from t0 to t1 and to t2 (highest MFV in t0 197.1 cm/s, in t1 172.8 cm/s [p = 0.012], in t2 159 cm/s [p = 0.002]). Regarding clinical outcomes, we observed a significant improvement in mean National Institutes of Health Stroke Scale scores from 17 to 16 in t1 (p < 0.001) and to 15 in t2 (p = 0.002).

CONCLUSIONS

BFV analyzed by TCD in patients with aSAH who developed DCI and were treated with milrinone or NE significantly decreased in a time-dependent way. Milrinone effectively decrease cerebral BFV, whereas NE do not. Clinical improvement was achieved with both treatment strategies.

Morphologic Variations in the Circle of Willis as a Risk Factor for Aneurysm Rupture in the Anterior and Posterior Communicating Arteries

BACKGROUND

Intracranial aneurysms are acquired abnormal vascular dilations. The most dangerous complication of a cerebral aneurysm is its rupture, with a high rate of mortality. This study aimed to determine whether there is an association between anatomic variations in the circle of Willis and ruptured aneurysms in the anterior and posterior communicating arteries.

METHODS

A cross-sectional study of adult patients with a diagnosis of intracranial aneurysm was carried out between March 2015 and March 2019. The patients were divided into groups of ruptured or unruptured aneurysm in the anterior and posterior communicating arteries.

RESULTS

A total of 132 patients with anterior and posterior communicating artery aneurysms were included. The presence of anatomic variation in the circle of Willis presented a statistically significant association with ruptured aneurysms (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.11-4.65; P = 0.024). There was a statistically significant difference between the presence of nonspherical aneurysm and rupture (OR, 6.9; 95% CI, 3.12-15.48; P < 0.0001). Multivariate logistic regression observed smoking (OR, 2.4; 95% CI, 1.01-5.9; P = 0.4), anterior complex variations (OR, 2.68; 95% CI, 1.01-7.18; P < 0.04), and nonspherical morphology (OR, 4.7; 95% CI, 1.93-11.45; P = 0.001) presented a statistically significant association with the rupture.

CONCLUSIONS

Our results suggest that the studied variations of the circle of Willis and nonspherical morphology, in addition to playing a role in the development of cerebral aneurysms, may contribute to their rupture.

Differential polarization and activation dynamics of systemic T helper cell subsets after aneurysmal subarachnoid hemorrhage (SAH) and during post-SAH complications

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. Devastating post-SAH complications, such as cerebral vasospasm (CVS), delayed cerebral ischemia or seizures to mention a few, are mainly responsible for the poor clinical outcome. Inflammation plays an indispensable role during early brain injury (EBI) and delayed brain injury (DBI) phases over which these complications arise. T helper cells are the major cytokine secreting cells of adaptive immunity that can polarize to multiple functionally unique sub-populations. Here, we investigate different CD4+ T cell subsets during EBI and DBI phases after SAH, and their dynamics during post-SAH complications. Peripheral venous blood from 15 SAH patients during EBI and DBI phases, was analyzed by multicolour flowcytometry. Different subsets of CD3+ CD4+ T cells were characterized by differential cell surface expression of CXCR3 and CCR6 into Th1, Th2, Th17, whereas Tregs were defined by CD25^hiCD127^lo. The analysis of activation states was done by the expression of stable activation markers CD38 and HLA-DR. Interestingly, compared to healthy controls, Tregs were significantly increased during both EBI and DBI phases. Different activation states of Tregs showed differential significant increase during EBI and DBI phases compared to controls. HLA-DR− CD38+ Tregs were significantly increased during DBI phase compared to EBI phase in SAH patients developing CVS, seizures and infections. However, HLA-DR− CD38− Tregs were significantly reduced during EBI phase in patients with cerebral ischemia (CI) compared to those without CI. HLA-DR− CD38− Th2 cells were significantly increased during EBI phase compared to controls. A significant reduction in Th17/Tregs and HLA-DR− CD38+ Th17/Tregs ratios was observed during both EBI and DBI phases compared to controls. While HLA-DR− CD38− Th17/Tregs and HLA-DR− CD38− Th1/Th2 ratios were impaired only during EBI phase compared to controls. In conclusion, CD4+ T cell subsets display dynamic and unique activation patterns after SAH and during the course of the manifestation of post-SAH complications, which may be helpful for the development of precision neurovascular care. However, to claim this, confirmatory studies with larger patient cohorts, ideally from different ethnic backgrounds, are required. Moreover, our descriptive study may be the grounds for subsequent lab endeavors to explore the underlying mechanisms of our observations.

Treatment of Subarachnoid Hemorrhage-associated Delayed Cerebral Ischemia With Milrinone: A Review and Proposal

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage continues to be associated with high levels of morbidity and mortality. This complication had long been thought to occur secondary to severe cerebral vasospasm, but expert opinion now favors a multifactorial etiology, opening the possibility of new therapies. To date, no definitive treatment option for DCI has been recommended as standard of care, highlighting a need for further research into potential therapies. Milrinone has been identified as a promising therapeutic agent for DCI, possessing a mechanism of action for the reversal of cerebral vasospasm as well as potentially anti-inflammatory effects to treat the underlying etiology of DCI. Intra-arterial and intravenous administration of milrinone has been evaluated for the treatment of DCI in single-center case series and cohorts and appears safe and associated with improved clinical outcomes. Recent results have also brought attention to the potential outcome benefits of early, more aggressive dosing and titration of milrinone. Limitations exist within the available data, however, and questions remain about the generalizability of results across a broader spectrum of patients suffering from DCI. The development of a standardized protocol for milrinone use in DCI, specifically addressing areas requiring further clarification, is needed. Data generated from a standardized protocol may provide the impetus for a multicenter, randomized control trial. We review the current literature on milrinone for the treatment of DCI and propose a preliminary standardized protocol for further evaluation of both safety and efficacy of milrinone.

Association of Serum Magnesium Levels With Risk of Intracranial Aneurysm: A Mendelian Randomization Study

Objective

Magnesium has been implicated in regulating blood pressure and vascular endothelial cell function, but its role in the pathophysiology of intracranial aneurysm is not known. Here we performed a Mendelian randomization analysis to investigate the association between serum magnesium concentration and risk of intracranial aneurysm.

Methods

Five single-nucleotide polymorphisms strongly associated with serum magnesium concentrations in a genome-wide association study in 23,829 individuals of European ancestry were used as genetic instruments. Genetic association estimates for intracranial aneurysm were obtained from a genome-wide association study in 79,429 individuals (7,495 cases and 71,934 controls). The inverse variance weighted method was used in the primary analyses to obtain the causal estimates.

Results

Higher genetically predicted serum magnesium concentrations were associated with lower risk of intracranial aneurysm. The odds ratios per 0.1 mmol/L increment in genetically predicted serum magnesium concentrations were 0.66 (95% confidence interval [CI] 0.49–0.91) for intracranial aneurysm (unruptured and ruptured combined), 0.57 (95% CI 0.30–1.06) for unruptured intracranial aneurysm, and 0.67 (95% CI 0.48–0.92) for aneurysmal subarachnoid hemorrhage.

Conclusion

This study provides evidence to support that increased serum magnesium concentrations reduce the risk of intracranial aneurysm and associated hemorrhage.

Flow Diversion in Acute Sub Arachnoid Haemorrhage: A Single Centre Five Year Experience

OBJECTIVES

The role of flow-diversion in acute sub-arachnoid haemorrhage (SAH) is controversial. Many of the published data warns of high rates of procedure-related complications and aneurysmal rebleed. This study evaluates the safety, efficacy, clinical and angiographic outcomes of acute flow-diversion at our institute.

METHODS

The institutional database from June 2015 to June 2020 was retrospectively reviewed for aneurysmal SAH (aSAH) treated with flow diversion. Clinical presentation, procedural details, complications, anti-platelet usage, rebleeding and aneurysm occlusion rates and outcomes were recorded.

RESULTS

22 (59% females; median age 56 years) consecutive patients were identified. None of them were on regular antiplatelets/anticoagulation in the 15-days preceding the treatment. The mean aneurysm diameter was 5.4 mm and the median delay to flow-diversion was 2 days. Almost 73% (16/22) of patients had adjunctive coiling in the same session. There was no aneurysmal rebleed at a median follow up of 8.5 months and 86.3% (19/22 patients) had good clinical outcomes (3-month MRS 0-2). Adverse events related to the flow diversion procedure were seen in 3 patients; none of them had a medium to long-term clinical consequence. Three patients died from complications of SAH, unrelated to the procedure. Vascular imaging follow-up was available for 20 patients and the complete aneurysm occlusion rate was 95%.

CONCLUSION

Flow-diversion could be a reasonably safe and effective technique for treating ruptured aneurysms in appropriately selected patients when conventional options of surgical clipping and coiling are considered challenging.

The Relationship of Morphological-Hemodynamic Characteristics, Inflammation, and Remodeling of Aneurysm Wall in Unruptured Intracranial Aneurysms

Aneurysm wall remodeling (AWR) is an important pathological characteristic in aneurysm wall, which was characterized by abnormal histological structure and inflammation infiltration. In the present study, the aim is to determine the relationships of morphological-hemodynamic characteristics, inflammation, and AWR in intracranial aneurysms (IAs), as well as the pathological basis of morphological-hemodynamic predictors to achieve IA development. For this end, 113 unruptured IAs were prospectively collected from 110 cases. In addition, patient-specific computational fluid dynamics and geometry were adopted to determine hemodynamic and morphological parameters. Moreover, Hematoxylin-Eosin staining was performed to identify the AWR. By performing immunofluorescence, the inflammatory markers were detected. Masson staining was conducted to characterize the characteristics of atherosclerosis in aneurysm wall. To demonstrate the parameters regarding the AWR, a multivariate logistic analysis was conducted. Besides, correlation analyses were conducted to verify the relationship between morphological-hemodynamic and pathological characteristics. For 113 unruptured IAs, no difference was identified in baseline information. AWR was demonstrated in 92 (81.4%) IAs. To be specific, the aneurysm size (odds ratio (OR), 2.63; confidence interval (CI), 1.04-6.67; P = 0.041), size ratio (SR; OR, 1.95; CI, 1.38-2.76; P < 0.001), normalized wall shear stress average (NWSSA; OR, 0.05; CI, 0.01-0.15; P = 0.007), and relative resident time (RRT; OR, 1.28; CI, 1.07-1.53; P = 0.007) were proved as the factors of AWR. As revealed from the results of immunofluorescence, aneurysm size, SR, NWSSA, and RRT were significantly correlated with the level of inflammation in IA tissues. Furthermore, Masson staining revealed that atherosclerosis area in IA tissues and NWSSA was correlated with RRT. In this study, SR, NWSSA, and RRT were demonstrated as the risk factors of AWR. The mentioned parameters could also reflect the characteristics of inflammation and atherosclerosis in aneurysm wall as well. This study revealed that biomechanical stress and inflammation in aneurysm wall are correlated, which might suggest the pathological evidence of morphological-hemodynamic predictors for IA development.

Pain Trajectories Following Subarachnoid Hemorrhage are Associated with Continued Opioid Use at Outpatient Follow-up

BACKGROUND

Subarachnoid hemorrhage (SAH) is characterized by the worst headache of life and associated with long-term opioid use. Discrete pain trajectories predict chronic opioid use following other etiologies of acute pain, but it is unknown whether they exist following SAH. If discrete pain trajectories following SAH exist, it is uncertain whether they predict long-term opioid use. We sought to characterize pain trajectories after SAH and determine whether they are associated with persistent opioid use.

METHODS

We reviewed pain scores from patients admitted to a single tertiary care center for SAH from November 2015 to September 2019. Group-based trajectory modeling identified discrete pain trajectories during hospitalization. We compared outcomes across trajectory groups using χ² and Kruskal-Wallis tests. Multivariable regression determined whether trajectory group membership was an independent predictor of long-term opioid use, defined as continued use at outpatient follow-up.

RESULTS

We identified five discrete pain trajectories among 305 patients. Group 1 remained pain free. Group 2 reported low scores with intermittent spikes and slight increase over time. Group 3 noted increasing pain severity through day 7 with mild improvement until day 14. Group 4 experienced maximum pain with steady decrement over time. Group 5 reported moderate pain with subtle improvement. In multivariable analysis, trajectory groups 3 (odds ratio [OR] 3.5; 95% confidence interval [CI] 1.5-8.3) and 5 (OR 8.0; 95% CI 3.1-21.1), history of depression (OR 3.6; 95% CI 1.3-10.0) and racial/ethnic minority (OR 2.3; 95% CI 1.3-4.1) were associated with continued opioid use at follow-up (median 62 days following admission, interquartile range 48-96).

CONCLUSIONS

Discrete pain trajectories following SAH exist. Recognition of pain trajectories may help identify those at risk for long-term opioid use.

Length of hospital stay in aneurysmal subarachnoid hemorrhage patients without vasospasm on angiography: potential for a fast-track discharge cohort

BACKGROUND

Patients with aneurysmal subarachnoid hemorrhage (aSAH) frequently suffer from vasospasm. We analyzed the association between absence of early angiographic vasospasm and early discharge.

METHODS

All aSAH patients treated from August 1, 2007, to July 31, 2019, at a single tertiary center were reviewed. Patients undergoing diagnostic digital subtraction angiography (DSA) on post-aSAH days 5 to 7 were analyzed; cohorts with and without angiographic vasospasm (angiographic reports by attending neurovascular surgeons) were compared. Primary outcome was hospital length of stay; secondary outcomes were intensive care unit length of stay, 30 day return to the emergency department (ED), and poor neurologic outcome, defined as a modified Rankin Scale (mRS) score >2.

RESULTS

A total of 298 patients underwent DSA on post-aSAH day 5, 6, or 7. Most patients (n=188, 63%) had angiographic vasospasm; 110 patients (37%) did not. Patients without vasospasm had a significantly lower mean length of hospital stay than vasospasm patients (18.0±7.1 days vs 22.4±8.6 days; p<0.001). The two cohorts did not differ significantly in the proportion of patients with mRS scores >2 at last follow-up or those returning to the ED before 30 days. After adjustment for Hunt and Hess scores, Fisher grade, admission Glasgow Coma Scale score, and age, logistic regression analysis showed that the absence of vasospasm on post-aSAH days 5-7 predicted discharge on or before hospital day 14 (OR 3.4, 95% CI 1.8 to 6.4, p<0.001).

CONCLUSION

Lack of angiographic vasospasm 5 to 7 days after aSAH is associated with shorter hospitalization, with no increase in 30 day ED visits or poor neurologic outcome.

The Utility of Computed Tomography Angiogram in Patients with Mild Traumatic Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) and traumatic subarachnoid hemorrhage (tSAH) differ significantly in their mortality and management. Although computed tomography angiography (CTA) is critical to guide timely interventions in aSAH, it lacks recognized benefit in assessing tSAH. Despite this, CTA commonly is included in tSAH evaluation.

OBJECTIVE

Determine if any clinically significant cerebral aneurysms are identified on CTA in emergency department (ED) patients with a tSAH.

METHODS

Retrospective observational study of consecutive blunt head trauma patients ages ≥ 16 years with Glasgow Coma Scale score (GCS) ≥ 13 who presented to an academic ED (100,000 annual visits) over a 7-year period. Those included had a CT-diagnosed SAH and underwent head CTA. The primary endpoint was the detection of any clinically significant brain aneurysms.

RESULTS

There were 297 patients that met the inclusion criteria. Twenty-six patients (8.8%) had an incidental aneurysm discovered; one underwent elective outpatient intervention. Aneurysm-positive patients were more likely to be female (69.2% vs. 46.9%, p = 0.003), age 60 years or older (80.8% vs. 52.4%, p = 0.005), and be on anticoagulation (42.3% vs. 28.0%, p = 0.03). There were no differences between the aneurysm-positive and -negative patients with respect to GCS, history of hypertension, or mechanism of injury.

CONCLUSIONS

In this 7-year retrospective chart review, CTA in patients with tSAH and GCS ≥ 13 did not reveal any clinically relevant cerebral aneurysms. One incidental aneurysm later underwent outpatient neurovascular intervention. In the absence of specific clinical concerns, CTA has minimal value in well-appearing patients with a tSAH.

Long non-coding RNA H19: Physiological functions and involvements in central nervous system disorders

Central nervous system (CNS) disorders are some of the most complex and challenging diseases because of the intricate structure and functions of the CNS. Long non-coding RNA (LncRNA) H19, which had been mistaken for "transcription noise" previously, has now been found to be closely related to the development and homeostasis of the CNS. Several recent studies indicate that it plays an important role in the pathogenesis, treatment, and even prognosis of CNS disorders. LncRNA H19 is correlated with susceptibility to various CNS disorders such as intracranial aneurysms, ischemic stroke, glioma, and neuroblastoma. Moreover, it participates in the pathogenesis of CNS disorders by regulating transcription, translation, and signaling pathways, suggesting that it is a promising biomarker and therapeutic target for these disorders. This article reviews the functions and mechanisms of lncRNA H19 in various CNS disorders, including cerebral ischemia, cerebral hemorrhage, glioma, pituitary adenoma, neuroblastoma, Parkinson's disease, Alzheimer's disease, traumatic spinal cord injury, neuropathic pain, and temporal lobe epilepsy, to provide a theoretical basis for further research on the role of lncRNA H19 in CNS disorders.

Circular RNA circDUS2 Is a Potential Biomarker for Intracranial Aneurysm

Background: CircRNAs have been found to play a crucial role in the pathological process of various kinds of diseases. However, the role of circRNAs in the formation and rupture of intracranial aneurysm is still unknown.

Methods: Differentially expressed circRNAs profiles between superficial temporal arteries (n = 5) and intracranial aneurysms (n = 5) were analyzed using the Arraystar human circRNAs microarray. Quantitative real-time PCR was utilized to validate the differential expression of circDUS2. Fluorescence in situ hybridization (FISH) was meant for the location of circDUS2 in human brain vascular smooth muscle cell (HBVSMC). Structural analysis was used to speculate on the function of circDUS2.

Results: Five hundred forty-three upregulated and 397 downregulated significantly in intracranial aneurysm as compared to superficial temporal arteries. Quantitative real-time PCR verified the elevated expression of the upregulated circDUS2. The FISH test revealed that circDUS2 is located in the cytoplasm of brain vascular smooth muscle cells.

Conclusion: This study showed differential expression data of circRNAs between superficial temporal artery and intracranial aneurysm and revealed that circDUS2 is a potential molecular marker for intracranial aneurysm.