Delayed cerebral ischaemia prevention and treatment after aneurysmal subarachnoid haemorrhage: a systematic review

Influence of cerebrospinal fluid drainage in the first days after aneurysm rupture on the severity of early brain injury following aneurysmal subarachnoid hemorrhage

PURPOSE

Progressive cerebral edema with refractory intracranial hypertension (ICP) requiring decompressive hemicraniectomy (DHC) is a severe manifestation of early brain injury (EBI) after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of the study was to investigate whether a more pronounced cerebrospinal fluid (CSF) drainage has an influence on cerebral perfusion pressure (CPP) and the extent of EBI after aSAH.

METHODS

Patients with aSAH and indication for ICP-monitoring admitted to our center between 2012 and 2020 were retrospectively included. EBI was categorized based on intracranial blood burden, persistent loss of consciousness, and SEBES (Subarachnoid Hemorrhage Early Brain Edema Score) score on the third day after ictus. The draining CSF and vital signs such as ICP and CPP were documented daily.

RESULTS

90 out of 324 eligible aSAH patients (28%) were included. The mean age was 54.2 ± 11.9 years. DHC was performed in 24% (22/90) of patients. Mean CSF drainage within 72 h after ictus was 168.5 ± 78.5 ml. A higher CSF drainage within 72 h after ictus correlated with a less severe EBI and a less frequent need for DHC (r=-0.33, p = 0.001) and with a higher mean CPP on day 3 after ictus (r = 0.2351, p = 0.02).

CONCLUSION

A more pronounced CSF drainage in the first 3 days of aSAH was associated with higher CPP and a less severe course of EBI and required less frequently a DHC. These results support the hypothesis that an early and pronounced CSF drainage may facilitate blood clearance and positively influence the course of EBI.

Effect of Intrathecal Eugenol on Cerebral Vasospasm in an Experimental Subarachnoid Hemorrhage Model

BACKGROUND

Eugenol has various curative properties. It affects the dilatation of cerebral arteries through voltage-dependent Ca2+ channel inhibition. This study is the first to explore the impact of eugenol on neuroprotection and vasospasm in an experimental subarachnoid hemorrhage (SAH) model.

METHODS

Twenty-four adult male Sprague-Dawley rats were indiscriminately separated into 3 groups: the control group (n = 8), the SAH group (n = 8), and the eugenol group (n = 8). A double-bleeding method was used. The eugenol group received intracisternal eugenol (Sigma-Aldrich, St. Louis, MO, USA) at 30 μg/20 μl after induction of SAH. On the day 7, all groups were euthanized. Measurements were taken for basilar artery wall thickness, lumen diameter, serum endothelin-1 (ET-1), and caspase-3 levels.

RESULTS

The eugenol group exhibited significantly lower wall thickness, ET-1, oxidative stress index, and caspase-3 levels compared to the SAH group. In comparison to the control group, the eugenol group showed a higher oxidative stress index along with higher ET-1 and caspase-3 levels, but these differences were not statistically significant. Wall thickness was significantly higher in the eugenol group than in the control group.

CONCLUSIONS

This study represents the first literature exploration of intrathecal eugenol's impact on vasospasm induced after experimental SAH. Administration of intrathecal eugenol demonstrates a positive effect on the treatment of experimental vasospasm as well as on the reduction of oxidative stress and apoptosis.

Taurine ameliorates sensorimotor function by inhibiting apoptosis and activating A2 astrocytes in mice after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a form of severe acute stroke with very high mortality and disability rates. Early brain injury (EBI) and delayed cerebral ischemia (DCI) contribute to the poor prognosis of patients with SAH. Currently, some researchers have started to focus on changes in amino acid metabolism that occur in brain tissues after SAH. Taurine is a sulfur-containing amino acid that is semi-essential in animals, and it plays important roles in various processes, such as neurodevelopment, osmotic pressure regulation, and membrane stabilization. In acute stroke, such as cerebral hemorrhage, taurine plays a neuroprotective role. However, the role of taurine after subarachnoid hemorrhage has rarely been reported. In the present study, we established a mouse model of SAH. We found that taurine administration effectively improved the sensorimotor function of these mice. In addition, taurine treatment alleviated sensorimotor neuron damage and reduced the proportion of apoptotic cells. Furthermore, taurine treatment enhanced the polarization of astrocytes toward the neuroprotective phenotype while inhibiting their polarization toward the neurotoxic phenotype. This study is the first to reveal the relationship between taurine and astrocyte polarization and may provide a new strategy for SAH research and clinical treatment.

Interventional Treatment of Symptomatic Vasospasm in the Setting of Traumatic Brain Injury: A Systematic Review of Reported Cases

Traumatic subarachnoid hemorrhage (tSAH) is frequently comorbid with traumatic brain injury (TBI) and may induce secondary injury through vascular changes such as vasospasm and subsequent delayed cerebral ischemia (DCI). While aneurysmal SAH is well studied regarding vasospasm and DCI, less is known regarding tSAH and the prevalence of vasospasm and DCI, the consequences of vasospasm in this setting, when treatment is indicated, and which management strategies should be implemented. In this article, a systematic review of the literature that was conducted for cases of symptomatic vasospasm in patients with TBI is reported, association with tSAH is reported, risk factors for vasospasm and DCI are summarized, and commonalities in diagnosis and management are discussed. Clinical characteristics and treatment outcomes of 38 cases across 20 studies were identified in which patients with TBI with vasospasm underwent medical or endovascular management. Of the patients with data available for each category, the average age was 48.7 ± 20.3 years (n = 31), the Glasgow Coma Scale score at presentation was 10.6 ± 4.5 (n = 35), and 100% had tSAH (n = 29). Symptomatic vasospasm indicative of DCI was diagnosed on average at postinjury day 8.4 ± 3.0 days (n = 30). Of the patients, 56.6% (n = 30) had a new ischemic change associated with vasospasm confirming DCI. Treatment strategies are discussed, with 11 of 12 endovascularly treated and 19 of 26 medically treated patients surviving to discharge. tSAH is associated with vasospasm and DCI in moderate and severe TBI, and patients with clinical and radiographic evidence of symptomatic vasospasm and subsequent DCI may benefit from endovascular or medical management strategies.

Intra-arterial nimodipine for the treatment of refractory delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is one of the main contributors to poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH). Endovascular spasmolysis with intra-arterial nimodipine (IAN) may resolve angiographic vasospasm, but its effect on infarct prevention and clinical outcome is still unclear. We report the effect of IAN on infarction rates and functional outcome in a consecutive series of SAH patients.

METHODS

To assess the effectiveness of IAN, we collected functional outcome data of all SAH patients referred to a single tertiary center since its availability (2011-2020). IAN was primarily reserved as a last tier option for DCI refractory to induced hypertension (iHTN). Functional outcome was assessed after 12 months according to the Glasgow Outcome Scale (GOS, favorable outcome = GOS4-5).

RESULTS

Out of 376 consecutive SAH patients, 186 (49.5%) developed DCI. Thereof, a total of 96 (25.5%) patients remained unresponsive to iHTN and received IAN. DCI-related infarction was observed in 44 (45.8%) of IAN-treated patients with a median infarct volume of 111.6 mL (Q1: 51.6 to Q3: 245.7). Clinical outcome was available for 84 IAN-treated patients. Of those, a total of 40 (47.6%) patients reached a favorable outcome after 1 year. Interventional complications were observed in 9 (9.4%) of the IAN-treated patients.

CONCLUSION

Intra-arterial spasmolysis using nimodipine infusion was associated with low treatment specific complications. Despite presenting a subgroup of severely affected SAH patients, almost half of IAN-treated patients were able to lead an independent life after 1 year of follow-up.

TRIAL REGISTRATION NUMBER

German Clinical Trial Register DRKS00030505.

Successful Fluid Management in Respiratory Failure due to Clazosentan Following a Cerebral Aneurysm Clipping: A Case Report

Clazosentan, a potent selective endothelin receptor subtype A antagonist, has been demonstrated to be effective in preventing cerebral vasospasms after subarachnoid hemorrhage. We report the successful management of respiratory failure due to pulmonary edema associated with clazosentan, with a hemodynamic monitoring system. A 49-year-old Japanese man underwent emergency clipping for a right internal carotid-posterior communicating artery aneurysm. The surgery and general anesthesia for the rupture proceeded with no complications. Clazosentan was administered from postoperative day 1 to prevent cerebral vasospasm. He presented with respiratory failure six days post surgery and chest X-ray imaging showed pulmonary edema. In our intensive care unit, the patient's N-terminal pro-brain natriuretic peptide was 476 pg/mL although trans-thoracic echography indicated a normal left ventricular ejection fraction (>60%) and normal diastolic function. The hemodynamic monitoring system showed 11 L/minute cardiac output and a cardiac index of 5.6 L/minute/m2. We thus diagnosed the cause of the patient's respiratory failure as due to excessive volume, as an adverse event of clazosentan. We changed the cerebral vasospasm-preventive drug to fasudil hydrochloride hydrate and forced urination. His body weight dropped approximately 9 kg as of day 9 in the ICU and he was weaned off the ventilator 23 days post surgery. This case indicates the importance of optimal infusion in patients with clazosentan. Optimal fluid management using a hemodynamic monitoring system could be useful for clazosentan-induced respiratory failure.

Clinical value of serum complement component 1q levels in the prognostic analysis of aneurysmal subarachnoid hemorrhage: a prospective cohort study

Objective

To analyze the relationship between serum complement component 1q (C1q) levels and functional prognosis in patients with aneurysmal subarachnoid hemorrhage (aSAH), and to reveal its clinical value.

Methods

In this prospective cohort study, we collected clinical data of aSAH patients admitted to the Department of Neurosurgery, Hangzhou First People's Hospital from January 2020 to October 2022. Parameters such as serum C1q levels, Hunt-Hess grade, modified Fisher grade, and the modified Rankin scale (mRS) at 3 months were included for evaluation. Patients were grouped based on the occurrence of delayed cerebral ischemia (DCI). Spearman rank correlation test and Kruskal-Wallis rank sum test were used to analyze the correlation between serum C1q levels, disease severity, and prognosis. Potential risk factors affecting prognosis and the occurrence of DCI were screened through Independent sample t-test or Mann-Whitney U test. Variables with significant differences (p < 0.05) were incorporated into a logistic regression model to identify independent risk factors affecting prognosis and DCI occurrence. Serum C1q levels were plotted as a ROC curve for predicting prognosis and DCI, and the area under the curve was calculated.

Results

A total of 107 aSAH patients were analyzed. Serum C1q levels positively correlated with Hunt-Hess grade, modified Fisher grade and mRS (all p < 0.001). Significant differences were observed in C1q levels among different Hunt-Hess grade, mFisher grade and mRS (all p < 0.001). Notably, higher serum C1q levels were seen in the poor prognosis group and DCI group, and correlated with worse prognosis (OR = 36.927, 95%CI 2.003-680.711, p = 0.015), and an increased risk for DCI (OR = 17.334, 95%CI 1.161-258.859, p = 0.039). ROC analysis revealed the significant discriminative power of serum C1q levels for poor prognosis (AUC 0.781; 95%CI 0.673-0.888; p < 0.001) and DCI occurrence (AUC 0.763; 95%CI 0.637-0.888; p < 0.001). Higher C1q levels independently predicted a poor prognosis and DCI with equivalent predictive abilities to Hunt-Hess grade and modified Fisher grade (both p < 0.05).

Conclusion

High levels of C1q in the blood is an independent risk factor for poor prognosis and the development of DCI in patients with aSAH. This can more objectively and accurately predict functional outcomes and the incidence of DCI. C1q may have a significant role in the mechanism behind DCI after aSAH.

Management of neurological complications related to aneurysmal subarachnoid hemorrhage: A comparison of the bedside therapeutic algorithms

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is of the most serious emergencies in neurosurgical practice and continues to be associated with high morbidity and mortality. Beyond securing the ruptured aneurysm to prevent a rebleed, physicians continue to be concerned about potential complications such as cerebral vasospasm-delayed cerebral ischemia (DCI), an area where management remains highly variable. This study aimed at reviewing the most recent literature and assessing any up-to-date schemes for treating the most common aSAH neurological complications in adults that can be applied in daily clinical practice towards optimising outcomes.

METHODS

A systematic review was performed according to PRISMA guidelines on the management of aSAH neurological complications in adults. The literature surveyed was between 2016 and 2022 inclusive, using the Pubmed search engine. Comparisons between the methods suggested by existing therapeutic algorithms were discussed.

RESULTS

Six stepwise algorithms assisting the decision-making for treating cerebral vasospasm-DCI were recognised and compared. No algorithm was found for the management of any other neurological complications of aSAH. Despite differences in the algorithms, induced hypertension and endovascular therapy were common treatments in all approaches. Controversy in the therapeutic process of these complications surrounds not only the variability of methods but also their optimal application towards clinical outcome optimisation.

CONCLUSIONS

A universal approach to managing aSAH complications is lacking. Despite advances in the techniques to secure a ruptured aneurysm, there persist a high rate of neurological deficit and mortality, and several unanswered questions. More research is required towards stratification of current treatment algorithms as per the quality of their evidence.

Chronological Change of the Clinical Features and Treatment Outcomes for Subarachnoid Hemorrhage in Japan: A Multicenter Retrospective Study

Aneurysmal subarachnoid hemorrhage (SAH) treatment has progressed, and patients are rapidly aging in Japan. Consequently, dynamic changes must have emerged in the clinical practice of SAH. This study aimed to elucidate chronological changes of aneurysmal SAH and the prognostic factors in the previous quarter century in Japan. We conducted a retrospective survey regarding aneurysmal SAH in eight institutions in Japan. The study included 848, 863, and 781 patients in the first (1989-1993), second (1999-2003), and third (2009-2013) periods, respectively. The chronological changes of factors that influenced the poor outcomes and differences between the nonelderly (<75 years) and elderly patients were investigated. Mean age was significantly higher in patients in the third period (61.4 years) than in those in the other two periods (first, 57.8 years; second, 59.5 years). During these periods, the proportion of good outcomes did not change; however, the mortality rate significantly decreased from 19% in the first period to 11% and 9.2% in the second and third periods, respectively. The poor outcome was mainly caused by the significantly higher incidence of systemic complication and procedural complication in the first period and the significantly lower incidence of delayed ischemic neurological deficit in the third period. The elderly patients had significantly poorer clinical outcomes than the nonelderly ones. During the last 25 years, the age of patients with aneurysmal SAH has rapidly increased. The study results may contribute to the improvement of the treatment strategy of SAH in advanced countries with a rapidly aging population.

Altered levels of transthyretin in human cerebral microdialysate after subarachnoid haemorrhage using proteomics; a descriptive pilot study

BACKGROUND

Subarachnoid haemorrhage (SAH) is one of the most severe forms of stroke in which delayed cerebral ischemia is one of the major complications. Neurointensive care aims at preventing and treating such complications and identification of biomarkers of early signs of ischemia might therefore be helpful.

METHODS

We aimed at describing proteome profile in cerebral microdialysate in four patients with aneurysmal SAH using two dimensional gel electrophoresis in combination with mass spectrometry in search for new biomarkers for delayed cerebral ischemia and to investigate if there were temporal fluctuations in those biomarkers over time after aneurysmal bleed.

RESULTS

The results showed transthyretin in nine different proteoforms (1001, 1102, 2101, 3101, 4101, 4102, 5001, 5101, 6101) in cerebral microdialysate samples from four patients having sustained SAH. Several proteoforms show highly differing levels and pooled analysis of all samples showed varying optical density related to time from aneurysmal bleed, indicating a temporal evolution.

CONCLUSIONS

Transthyretin proteoforms have not earlier been shown in cerebral microdialysate after SAH and we describe differing levels based on proteoform as well as time from subarachnoid bleed. Transthyretin is well known to be synthetized in choroid plexus, whilst intraparenchymal synthesis remains controversial. The results need to be confirmed in larger studies in order to further describe transthyretin.

Effect of nimodipine combined with atorvastatin calcium on microinflammation and oxidative stress levels in patients with cerebral vasospasm after subarachnoid hemorrhage

Objective

To evaluate the effect of nimodipine combined with atorvastatin calcium on the micro inflammation and oxidative stress levels in patients with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) and its clinical implications.

Methods

A total of 80 patients with CVS caused by SAH who had been admitted to Baoding First Central Hospital from August 2021 to August 2022 were selected and randomly divided into two groups. The control group underwent conventional symptomatic treatment, while the experimental group was administered nimodipine combined with atorvastatin calcium on the basis of conventional treatment. The changes in the micro inflammatory cytokines and oxidative stress factors in the two groups were compared, as well as the differences in clinical efficacy and incidence of adverse drug reactions.

Result

After treatment, the levels of inflammatory cytokines in the experimental group decreased more significantly than those in the control group (p=0.00). After treatment, the serum levels of oxidative stress factors were obviously higher in the experimental group than in the control group (p=0.00). After treatment, the total efficacy was 77.5% in the experimental group and 55% in the control group, and the difference was statistically significant (p=0.04).

Conclusions

Nimodipine combined with atorvastatin calcium could significantly improve the clinical symptoms in patients with CVS after SAH, which would be beneficial, safe, and effective for the patient's recovery.

Effect of early stellate ganglion block in cerebral vasospasm after aneurysmal subarachnoid hemorrhage (BLOCK-CVS): study protocol for a randomized controlled trial

Introduction

Stellate ganglion block has been reported to expand cerebral vessels and alleviate vasospasm after aneurysmal subarachnoid hemorrhage. However, the causal relationship between early stellate ganglion block and cerebral vasospasm prevention has not yet been established. The purpose of this study was to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment for cerebral vasospasm and delayed cerebral ischemia.

Methods/design

This is a single-center, prospective, randomized, controlled, blinded endpoint assessment superiority trial. A total of 228 patients will be randomized within 48 h of aneurysmal subarachnoid hemorrhage onset in a 1:1 ratio into two groups, one group receiving an additional e-SGB and the other group receiving only a camouflaging action before anesthesia induction in the operating room. The primary outcome is the incidence of symptomatic vasospasm within 14 days after aSAH. Further safety and efficacy parameters include the incidence of radiographic vasospasm, new cerebral infarction, postoperative delirium, and complications up to 90 days after surgery; postoperative cerebral hemodynamics; Mini-Mental State Examination score; modified Rankin scale score; and all-cause mortality up to 90 days after surgery.

Discussion

This is a randomized controlled trial to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment to reduce cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. If the results are positive, it may provide a new direction for the prevention and treatment of cerebral vasospasm and delayed cerebral ischemia.

Trial registration

The study was registered on Clincaltrials.gov on December 13, 2020 (NCT04691271).

Revisiting the Timeline of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: Toward a Temporal Risk Profile

BACKGROUND

Delayed cerebral ischemia (DCI) is one of the main determinants of clinical outcome after aneurysmal subarachnoid hemorrhage (SAH). The classical description of risk for DCI over time is currently based on the outdated concept of angiographic vasospasm. The goal of this study was to assess the temporal risk profile of DCI, defined by extended clinical and radiological criteria, as well as the impact the time point of DCI onset has on clinical outcome.

METHODS

All patients with aneurysmal SAH referred to a single tertiary care center between 2010 and 2018 were considered for inclusion. This study was designed as a retrospective cohort analysis and data were extracted from existing patient files. In conscious patients, DCI was diagnosed clinically, and in unconscious patients, diagnosis was based on perfusion computed tomography imaging and multimodal neuromonitoring. Extended Glasgow Outcome Scale scores were assessed after 12 months and compared between patients with early (< day 7) and late (≥ day 7) DCI onset.

RESULTS

The median delay from day of the hemorrhage (day 0) until detection of the first DCI event was 7.0 days, with an interquartile range of 5 days. The probability of DCI development over time demonstrated a bimodal distribution with a peak risk on day 5 (0.084; confidence interval 0.05.5-0.122) and a second peak on day 9 (0.077; confidence interval 0.045-0.120). A total of 27 patients (15.6%) suffered dominant hemispheric or severe bilateral DCI-related infarctions, resulting in the withdrawal of technical life support. Of those, the majority (20 patients, 22.2%) presented with early DCI onset (vs. late onset: 7 patients, 8.4%; p = 0.013).

CONCLUSIONS

The risk profile of DCI over time mirrors the description of angiographic vasospasm; however, it comes with an added timely delay of 1 to 2 days. Early occurrence of DCI (before day 7) is associated with a higher infarct load and DCI-related mortality. Although the exact causal relationship remains to be determined, the time point of DCI onset may serve as an independent prognostic criterion in decision-making.

The Local Intraarterial Administration of Nimodipine Might Positively Affect Clinical Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage and Delayed Cerebral Ischemia

The effect of the intraarterial administration of nimodipine as a rescue measure to treat delayed vasospasm after aSAH remains understudied; therefore, we evaluated its effect on short- and long-term functional and neuropsychological outcomes after aSAH. In this prospective observational study, a total of 107 consecutive patients treated for aSAH of WFNS grades I−V were recruited. At follow-up visits 3-, 12- and 24-months after the hemorrhage, functional outcome was assessed using the Extended Glasgow Outcome (GOSE) and modified Rankin (mRS) scales, while neurocognitive function was evaluated using the screening module of the Neuropsychological Assessment Battery (NAB-S). The outcome of patients, who had received rescue therapy according to the local standard treatment protocol (interventional group, n = 37), and those, who had been treated conservatively (conservative group, n = 70), were compared. Even though significantly more patients in the interventional treatment group suffered from high-grade aSAH (WFNS Grades IV and V, 54.1% vs. 31.4%, p = 0.04) and required continuous drainage of cerebrospinal fluid at discharge (67.7% vs. 37.7%, p = 0.02) compared to the control group, significant differences in functional outcome were present only at discharge and three months after the bleeding (GOSE > 4 in 8.1% vs. 41.4% and 28.6% vs. 72.7%, p < 0.001 and p = 0.01 for the interventional and control group, respectively). Thereafter, group differences were no longer significant. While significantly more patients in the intervention group had severe neuropsychological deficits (76.3% vs. 36.0% and 66.7% vs. 29.2%, p = 0.04 and 0.05, respectively) and were unable to work (5.9% vs. 38.1%, p = 0.03 at twelve months) at three and twelve months after the hemorrhage, no significant differences between the two groups could be detected at long-term follow-up. The presence of moderate neuropsychological impairments did not significantly differ between the groups at any timepoint. In conclusion, despite initially being significantly more impaired, patients treated with intraarterial administration of nimodipine reached the same functional and neuropsychological outcomes at medium- and long-term follow-up as conservatively treated patients suggesting a potential beneficial effect of intraarterial nimodipine treatment for delayed vasospasm after aSAH.

Challenges in the hemodynamic management of acute nontraumatic neurological injuries

PURPOSE OF REVIEW

To appraise the evidence from the literature and suggest an integrated hemodynamic approach of early and delayed phases of acute ischemic stroke (AIS), subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH).

RECENT FINDINGS

In AIS, the research aims to evaluate the optimal pressure control before, during and after the revascularization, to optimize the perfusion in the ischemic areas, minimizing the risk of hemorrhage or secondary damage to already infarcted areas. In the early phase of SAH, systemic pressure should be controlled to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure. The late phase aims to minimize the risk of cerebral vasospasm by adapting systemic pressure and volemia to cerebral and systemic physiological hemodynamic targets. In the mild-to-moderate ICH, achieving SAP of less than 140 mmHg and greater than 110 mmHg may be considered as a beneficial target. Caution should be considered in lowering intensively SAP in severe ICH.

SUMMARY

In nontraumatic brain injuries, the hemodynamic management is strictly related to fluctuating physiology of these diseases, needing a strict control of pressure and flow variable to ensure both cerebral and systemic homeostasis.

Mitigation of Blood Load Impact in Patients with Subarachnoid Hemorrhage by Cisternal Lavage

OBJECT

The initial amount of subarachnoid and ventricular blood is an important prognostic factor for outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). In this comparative study of an unselected aSAH-population, we assess the modifiability of these factors by implementation of blood clearance by cisternal lavage.

METHODS

All patients with aSAH treated in our department between October 2011 and October 2019 (8 years, n = 458) were included in our study. In the first 4-year period (BEFORE, n = 237), patients were treated according to international guidelines. In the second 4-year period (AFTER, n = 221), cisternal lavage methods were available and applied in 72 high-risk patients (32.5%). The cisternal and ventricular blood load was recorded by the Hijdra score. Multivariable regression models were used to assess the prognostic significance of risk factors, including blood load, in relation to common aSAH characteristics in both study groups.

RESULTS

Worse neurological outcomes (mRS > 3) occurred in the BEFORE population with 41.45% versus 30.77% in the AFTER cohort, 6 months after aSAH (HR: 1.59, 95% CI 1.08-2.34, p = 0.01). Admission WFNS grade, comorbidities (Charlson Comorbidity Index), herniation signs, concomitant intracerebral hemorrhage, and the development of delayed cerebral infarction were strongly associated with poor outcome in both study groups. Intraventricular and cisternal blood load and, particularly, a cast fourth ventricle (Cast 4) represented strong prognosticators of poor neurological outcome in the BEFORE cohort. This effect was lost after implementation of cisternal lavage (AFTER cohort).

CONCLUSION

Cisternal and ventricular blood load - in particular: a Cast 4 - represent important prognosticators in patients with aSAH. They are, however, amenable to modification by blood clearing therapies.

A Double-Blind, Randomized, Placebo-Controlled Trial of Soluble Epoxide Hydrolase Inhibition in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Epoxyeicosatrienoates (EETs) are endogenous regulators of neuroinflammation and cerebral blood flow. Their metabolism to dihydroxyeicosatrienoates (DHETs) is catalyzed by soluble epoxide hydrolase (sEH). After subarachnoid hemorrhage (SAH), EETs' pathway amplification may be a therapeutic target for the prevention of delayed cerebral ischemia (DCI). We conducted a double-blind, placebo-controlled, phase Ib randomized trial of GSK2256294, a pharmacologic inhibitor of sEH, to evaluate the safety profile and to assess biomarkers of neurovascular inflammation in patients with aneurysmal SAH.

METHODS

Patients were randomly assigned to receive 10 mg of GSK2256294 or a placebo treatment once daily for 10 days, beginning within 72 hours after aneurysm rupture. The primary study end point was safety. Secondary end points included serum and cerebrospinal fluid (CSF) EETs-to-DHETs ratio, cytokine levels, and serum endothelial injury biomarkers, measured at day 7 and day 10 after SAH. Tertiary end points included neurologic status, disposition, length of stay, incidence of DCI, and mortality; these were assessed at hospital discharge and at 90 days.

RESULTS

Ten patients received GSK2256294 and nine patients received a placebo. There were no adverse events related to the study drug. GSK2256294 administration resulted in a significant increase in the EET/DHET ratio at day 7 and day 10 in serum, but not in the CSF. There was a trend for decreased CSF inflammatory cytokines following GSK2256294 administration, but this did not reach statistical significance.

CONCLUSIONS

GSK2256294 administration was safe and well tolerated in critically ill patients with SAH, producing an increase in serum EETs and the EET-to-DHET ratio. Our findings support future studies in a larger population to evaluate the role of sEH inhibition in the prevention of DCI after SAH and other forms of brain injury and inflammatory conditions.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT03318783.

Interventions for altering blood pressure in people with acute subarachnoid haemorrhage

BACKGROUND

Subarachnoid haemorrhage has an incidence of up to nine per 100,000 person-years. It carries a mortality of 30% to 45% and leaves 20% dependent in activities of daily living. The major causes of death or disability after the haemorrhage are delayed cerebral ischaemia and rebleeding. Interventions aimed at lowering blood pressure may reduce the risk of rebleeding, while the induction of hypertension may reduce the risk of delayed cerebral ischaemia. Despite the fact that medical alteration of blood pressure has been clinical practice for more than three decades, no previous systematic reviews have assessed the beneficial and harmful effects of altering blood pressure (induced hypertension or lowered blood pressure) in people with acute subarachnoid haemorrhage.

OBJECTIVES

To assess the beneficial and harmful effects of altering arterial blood pressure (induced hypertension or lowered blood pressure) in people with acute subarachnoid haemorrhage.

SEARCH METHODS

We searched the following from inception to 8 September 2020 (Chinese databases to 27 January 2019): Cochrane Stroke Group Trials register; CENTRAL; MEDLINE; Embase; five other databases, and five trial registries. We screened reference lists of review articles and relevant randomised clinical trials.

SELECTION CRITERIA

Randomised clinical trials assessing the effects of inducing hypertension or lowering blood pressure in people with acute subarachnoid haemorrhage. We included trials irrespective of publication type, status, date, and language.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We assessed the risk of bias of all included trials to control for the risk of systematic errors. We performed trial sequential analysis to control for the risks of random errors. We also applied GRADE. Our primary outcomes were death from all causes and death or dependency. Our secondary outcomes were serious adverse events, quality of life, rebleeding, delayed cerebral ischaemia, and hydrocephalus. We assessed all outcomes closest to three months' follow-up (primary point of interest) and maximum follow-up.

MAIN RESULTS

We included three trials: two trials randomising 61 participants to induced hypertension versus no intervention, and one trial randomising 224 participants to lowered blood pressure versus placebo. All trials were at high risk of bias. The certainty of the evidence was very low for all outcomes. Induced hypertension versus control Two trials randomised participants to induced hypertension versus no intervention. Meta-analysis showed no evidence of a difference between induced hypertension versus no intervention on death from all causes (risk ratio (RR) 1.60, 95% confidence interval (CI) 0.57 to 4.42; P = 0.38; I² = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analyses showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. Meta-analysis showed no evidence of a difference between induced hypertension versus no intervention on death or dependency (RR 1.29, 95% CI 0.78 to 2.13; P = 0.33; I² = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analyses showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. Meta-analysis showed no evidence of a difference between induced hypertension and control on serious adverse events (RR 2.24, 95% CI 1.01 to 4.99; P = 0.05; I² = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. One trial (41 participants) reported quality of life using the Stroke Specific Quality of Life Scale. The induced hypertension group had a median of 47 points (interquartile range 35 to 55) and the no-intervention group had a median of 49 points (interquartile range 35 to 55). The certainty of evidence was very low. One trial (41 participants) reported rebleeding. Fisher's exact test (P = 1.0) showed no evidence of a difference between induced hypertension and no intervention on rebleeding. The certainty of evidence was very low. Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. One trial (20 participants) reported delayed cerebral ischaemia. Fisher's exact test (P = 1.0) showed no evidence of a difference between induced hypertension and no intervention on delayed cerebral ischaemia. The certainty of the evidence was very low. Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. None of the trials randomising participants to induced hypertension versus no intervention reported on hydrocephalus. No subgroup analyses could be conducted for trials randomising participants to induced hypertension versus no intervention. Lowered blood pressure versus control One trial randomised 224 participants to lowered blood pressure versus placebo. The trial only reported on death from all causes. Fisher's exact test (P = 0.058) showed no evidence of a difference between lowered blood pressure versus placebo on death from all causes. The certainty of evidence was very low.

AUTHORS' CONCLUSIONS

Based on the current evidence, there is a lack of information needed to confirm or reject minimally important intervention effects on patient-important outcomes for both induced hypertension and lowered blood pressure. There is an urgent need for trials assessing the effects of altering blood pressure in people with acute subarachnoid haemorrhage. Such trials should use the SPIRIT statement for their design and the CONSORT statement for their reporting. Moreover, such trials should use methods allowing for blinded altering of blood pressure and report on patient-important outcomes such as mortality, rebleeding, delayed cerebral ischaemia, quality of life, hydrocephalus, and serious adverse events.

Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is the most feared complication of aneurysmal subarachnoid hemorrhage (aSAH). It increases the mortality and morbidity associated with aSAH. Previously, large cerebral artery vasospasm was thought to be the sole major contributing factor associated with increased risk of DCI. Recent literature has challenged this concept. We conducted a literature search using PUBMED as the prime source of articles discussing various other factors which may contribute to the development of DCI both in the presence or absence of large cerebral artery vasospasm. These factors include microvascular spasm, micro-thrombosis, cerebrovascular dysregulation, and cortical spreading depolarization. These factors collectively result in inflammation of brain parenchyma, which is thought to precipitate early brain injury and DCI. We conclude that diagnostic modalities need to be refined in order to diagnose DCI more efficiently in its early phase, and newer interventions need to be developed to prevent and treat this condition. These newer interventions are currently being studied in experimental models. However, their effectiveness on patients with aSAH is yet to be determined.

Argon treatment after experimental subarachnoid hemorrhage: evaluation of microglial activation and neuronal survival as a subanalysis of a randomized controlled animal trial

Hereinafter, we evaluate argon's neuroprotective and immunomodulatory properties after experimental subarachnoid hemorrhage (SAH) examining various localizations (hippocampal and cortical regions) with respect to neuronal damage and microglial activation 6, 24 and 72 hours after SAH. One hour after SAH (endovascular perforation rat model) or sham surgery, a mixture of gas containing 50% argon (argon group) or 50% nitrogen (control group) was applied for 1 hour. At 6 hours after SAH, argon reduced neuronal damage in the hippocampal regions in the argon group compared to the control group (P < 0.034). Hippocampal microglial activation did not differ between the treatment groups over time. The basal cortical regions did not show a different lesion pattern, but microglial activation was significantly reduced in the argon group 72 hours after SAH (P = 0.034 vs. control group). Whereas callosal microglial activation was significantly reduced at 24 hours in the argon-treated group (P = 0.018). Argon treatment ameliorated only early hippocampal neuronal damage after SAH. Inhibition of microglial activation was seen in some areas later on. Thus, argon may influence the microglial inflammatory response and neuronal survival after SAH; however, due to low sample sizes the interpretation of our results is limited. The study protocol was approved by the Government Agency for Animal Use and Protection (Protocol number: TVA 10416G1; initially approved by the "Landesamt für Natur, Umwelt und Verbraucherschutz NRW," Recklinghausen, Germany, on April 28, 2009).

Near-Infrared Spectroscopy in Neurocritical Care: A Review of Recent Updates

Neurocritical diseases and conditions are common causes of long-term disability and mortality. Early recognition and management of neurocritically ill patients is a significant challenge for neurosurgeons, neurologists, and neurointensivists. Although cerebral angiography, magnetic resonance imaging, computed tomography, and radionuclide imaging are useful in neuromonitoring and neuroimaging, they have several important limitations: they are not readily available, cannot be used for a continuous assessment of cerebral function, and frequently require patient transport to the radiological department. Near-infrared spectroscopy (NIRS) is an inexpensive, portable, noninvasive method that does not require advanced expertise and can be used at the bedside for critically ill patients without moving them to the radiology department. NIRS can detect and monitor multiple critical parameters, including cerebral oximetry, intracranial pressure, temperature, and cerebral blood flow. NIRS can be valuable for a wide variety of neurocritical diseases and conditions, such as ischemic and hemorrhagic strokes, severe traumatic brain injury, brain tumors, and perioperative neurosurgery. Although NIRS has been studied extensively in multiple neurocritical conditions, more evidence on its application is needed.

Monocyte-based inflammatory indices predict outcomes following aneurysmal subarachnoid hemorrhage

The contribution of specific immune cell populations to the post-hemorrhagic inflammatory response in aneurysmal subarachnoid hemorrhage (aSAH) and correlations with clinical outcomes, such as vasospasm and functional status, remains unclear. We aimed to compare the predictive value of leukocyte ratios that include monocytes as compared to the neutrophil-to-lymphocyte ratio (NLR) in aSAH. A prospectively accrued database of consecutive patients presenting to our institution with aSAH between January 2013 and December 2018 was used. Patients with signs and symptoms of infection (day 1-3) were excluded. Admission values of the NLR, monocyte-neutrophil-to-lymphocyte ratio (M-NLR), and lymphocyte-to-monocyte ratio (LMR) were calculated. Associations with functional status, the primary outcome, and vasospasm were evaluated using univariable and multivariable logistic regression analyses. In the cohort of 234 patients with aSAH, the M-NLR and LMR, but not the NLR, were significantly associated with poor functional status (modified Rankin scale > 2) at 12-18 months following discharge (p = 0.001, p = 0.023, p = 0.161, respectively). The area under the curve for predicting poor functional status was significantly lower for the NLR (0.543) compared with the M-NLR (0.603, p = 0.024) and LMR (0.608, p = 0.040). The M-NLR (OR = 1.01 [1.01-1.02]) and LMR (OR = 0.88 [0.78-0.99]) were independently associated with poor functional status while controlling for age, hypertension, Fisher grade, and baseline clinical status. The LMR was significantly associated with vasospasm (OR = 0.84 [0.70-0.99]) while adjusting for age, hypertension, Fisher grade, aneurysm size, and current smoking. Inflammatory indices that incorporate monocytes (e.g., M-NLR and LMR), but not those that include only neutrophils, predict outcomes after aSAH.

Predictive Relevance of Early Temperature Elevation on the Risk of Delayed Cerebral Ischemia Development Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Fever in aneurysmal subarachnoid hemorrhage (aSAH) has been associated with delayed cerebral ischemia (DCI), but its relevance in risk stratification has not been explored. This study investigated whether early temperature elevation following aSAH predicts impending clinical deterioration caused by DCI.

METHODS

Relevant cases were identified from a prospectively maintained database for consecutive patients with aSAH treated at our center between July 2015 and January 2020. Temperature readings obtained every 2 hours for individual patients from admission through day 14 were recorded and analyzed. Demographic, clinical, treatment, and angiographic data were extracted from the electronic medical record. The primary end point was the occurrence of DCI (clinical and radiographic vasospasm). Multivariate logistic regression analyses were performed to account for patient age, smoking status, and VASOGRADE classification.

RESULTS

The study included 175 patients (124 women) with aSAH. The median age at diagnosis was 55.4 years (range, 20.5-87.2 years). Clinical DCI occurred in 58 patients; 2 (1.1%) responded to hemodynamic augmentation, and 56 (32.0%) required intra-arterial therapy. Temperature graphs showed a marked divergence on day 4 between clinical DCI and non-DCI groups (1.12°C ± 0.15°C and 0.76°C ± 0.08°C, respectively, P = 0.007). Patients with temperature elevation ≥2.5°C on day 4 or 5 compared with their admission temperature were more likely to clinically deteriorate owing to DCI (odds ratio 4.55, 95% confidence interval 1.31-15.77, P = 0.017).

CONCLUSIONS

Temperature elevation of ≥2.5°C on day 4 or 5 compared with baseline suggests a greater risk of clinical deterioration owing to DCI.

High Mobility Group Box-1 and Blood-Brain Barrier Disruption

Increasing evidence suggests that inflammatory responses are involved in the progression of brain injuries induced by a diverse range of insults, including ischemia, hemorrhage, trauma, epilepsy, and degenerative diseases. During the processes of inflammation, disruption of the blood–brain barrier (BBB) may play a critical role in the enhancement of inflammatory responses and may initiate brain damage because the BBB constitutes an interface between the brain parenchyma and the bloodstream containing blood cells and plasma. The BBB has a distinct structure compared with those in peripheral tissues: it is composed of vascular endothelial cells with tight junctions, numerous pericytes surrounding endothelial cells, astrocytic endfeet, and a basement membrane structure. Under physiological conditions, the BBB should function as an important element in the neurovascular unit (NVU). High mobility group box-1 (HMGB1), a nonhistone nuclear protein, is ubiquitously expressed in almost all kinds of cells. HMGB1 plays important roles in the maintenance of chromatin structure, the regulation of transcription activity, and DNA repair in nuclei. On the other hand, HMGB1 is considered to be a representative damage-associated molecular pattern (DAMP) because it is translocated and released extracellularly from different types of brain cells, including neurons and glia, contributing to the pathophysiology of many diseases in the central nervous system (CNS). The regulation of HMGB1 release or the neutralization of extracellular HMGB1 produces beneficial effects on brain injuries induced by ischemia, hemorrhage, trauma, epilepsy, and Alzheimer’s amyloidpathy in animal models and is associated with improvement of the neurological symptoms. In the present review, we focus on the dynamics of HMGB1 translocation in different disease conditions in the CNS and discuss the functional roles of extracellular HMGB1 in BBB disruption and brain inflammation. There might be common as well as distinct inflammatory processes for each CNS disease. This review will provide novel insights toward an improved understanding of a common pathophysiological process of CNS diseases, namely, BBB disruption mediated by HMGB1. It is proposed that HMGB1 might be an excellent target for the treatment of CNS diseases with BBB disruption.

The role of immune inflammation in aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating disease, which mainly caused by the rupture of an intracranial aneurysm. Clinical trials have demonstrated that cerebral vasospasm (CVS) is not the sole contributor to delayed cerebral ischemia (DCI) and poor outcomes in patients with aSAH. Currently, accumulating evidence suggests that early brain injury (EBI), which occurs within 72 h after the onset of aSAH, lays the foundation for subsequent pathophysiological changes and poor outcomes of patients. The pathological mechanisms of EBI mainly include increased intracranial pressure, oxidative stress, neuroinflammation, blood-brain barrier (BBB) disruption, cerebral edema and cell death. Among them, the brain immune inflammatory responses involve a variety of immune cells and active substances, which play an important role in EBI after aSAH and may be related to DCI and long-term outcomes. Thus, attention should be paid to strategies targeting cerebral immune inflammatory responses. In this review, we discuss the role of immune inflammatory responses in the occurrence and development of aSAH, as well as some inflammatory biomarkers related to CVS, DCI, and aSAH outcomes. In addition, we also summarize the potential therapeutic drugs that target cerebral immune inflammatory responses for patients with aSAH in current research.

Efficacy and safety of cilostazol-nimodipine combined therapy on delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage: a prospective, randomised, double-blinded, placebo-controlled trial protocol

INTRODUCTION

Delayed cerebral ischaemia (DCI) due to cerebral vasospasm (cVS) remains the foremost contributor to morbidity and mortality following aneurysmal subarachnoid haemorrhage (aSAH). Past efforts in preventing and treating DCI have failed to make any significant progress. To date, our most effective treatment involves the use of nimodipine, a calcium channel blocker. Recent studies have suggested that cilostazol, a platelet aggregation inhibitor, may prevent cVS. Thus far, no study has evaluated the effect of cilostazol plus nimodipine on the rate of DCI following aSAH.

METHODS AND ANALYSIS

This is a multicentre, double-blinded, randomised, placebo-controlled superiority trial investigating the effect of cilostazol on DCI. Data concerning rates of DCI, symptomatic and radiographic vasospasm, length of intensive care unit stay, and long-term functional and quality-of-life (QoL) outcomes will be recorded. All data will be collected with the aim of demonstrating that the use of cilostazol plus nimodipine will safely decrease the incidence of DCI, and decrease the rates of both radiographic and symptomatic vasospasm with subsequent improvement in long-term functional and QoL outcomes when compared with nimodipine alone.

ETHICS AND DISSEMINATION

Ethical approval was obtained from all participating hospitals by the Ascension Providence Hospital Institutional Review Board. The results of this study will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04148105.

Bibliometric Analysis of the Top 100 Most Cited Articles on Cerebral Vasospasm

OBJECTIVE

Bibliometric analysis reflects the scientific recognition and influential performance of a published article within its field. Our aim is to identify and analyze the top 100 most-cited articles on cerebral vasospasm.

METHODS

A title-specific search was carried out using the Scopus database. The top 100 cited articles including the keywords "Cerebral Vasospasm" AND "Vasospasm" were retrieved and stratified in a descending order: title, authors, institution, publishing journal, country of origin, year of publication, and topic of each article were studied.

RESULTS

The top 100 articles have an accumulative citation count of 20,972, with 209 average citations per article. Publication dates ranged from 1968 to 2012, with the most productive years between 1998 and 2005. Clinical studies are the most frequent category, followed by pathophysiology. The list includes 7 clinical trials, which received accumulative citations of 1525. The top cited article had received 2109 citations, with 52.7 citations per year. The top 100 articles were published across 14 countries, with most originating from the United States. The lead research institution was the University of Alberta. The most used journal was Journal of Neurosurgery.

CONCLUSIONS

Bibliometric analysis has garnered major interest in recent years. It shows the publication trends, knowledge evolution, and evidence-based practice throughout the years. The collection of highly cited articles may assist physicians in gaining a better understanding of the nature of cerebral vasospasm and optimize their clinical practice.

Metabolic Parameters Influence Brain Infarction and Outcome after Resection of Brain Metastases

Perioperative infarction in brain tumor surgery occurs in about 30-80% of cases and is strongly associated with poor patient outcomes and longer hospital stays. Risk factors contributing to postoperative brain infarction should be assessed. We retrospectively included all patients who underwent surgery for brain metastases between January 2015 and December 2017. Hemodynamic parameters were analyzed and then correlated to postoperative infarct volume and overall survival. Of 249 patients who underwent biopsy or resection of brain metastases during that time, we included 234 consecutive patients in this study. In total, 172/249 patients showed ischemic changes in postoperative magnet resonance imaging (MRI) (73%). Independent risk factors for postoperative brain infarction were perioperative blood loss (rho 0.189, p = 0.00587), blood glucose concentration (rho 0.206, p = 0.00358), blood lactate concentration (rho 0.176; p = 0.0136) and cumulative time of reduced PaCO₂ (rho -0.142; p = 0.0445). Predictors for reduced overall survival were blood lactate (p = 0.007) and blood glucose levels (p = 0.032). Other hemodynamic parameters influenced neither infarct volume, nor overall survival. Intraoperative elevated lactate and glucose levels are independently associated with postoperative brain infarction in surgery of brain metastases. Furthermore, they might predict reduced overall survival after surgery. Blood loss during surgery also leads to more cerebral ischemic changes. Close perioperative monitoring of metabolism might reduce those complications.

Beta-Blockade in Aneurysmal Subarachnoid Hemorrhage: a Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVE

Sympathetic nervous system activation after aneurysmal subarachnoid hemorrhage (aSAH) is associated with complications and poor outcome. In this systematic review and meta-analysis, we investigate the effect of beta-blockers on outcome after aSAH.

METHODS

The review was prospectively registered with PROSPERO (CRD42019111784). We performed a systematic literature search of MEDLINE, EMBASE, the Cochrane Library, published conference proceedings, and abstracts. Eligible studies included both randomized controlled trials and observational studies up to October 2018, reporting the effect of beta-blocker therapy on the following outcomes in aSAH: mortality, vasospasm, delayed cerebral ischemia, infarction or stroke, cardiac dysfunction, and functional outcomes. Studies involving traumatic SAH were excluded. Citations were reviewed, and data extracted independently by two investigators using a standardized proforma.

RESULTS

We identified 819 records with 16 studies (four were randomized controlled trials) including 6702 patients selected for analysis. Exposure to beta-blockade either before or after aSAH was associated with a significant reduction in unadjusted mortality (RR 0.63, 95% CI 0.42-0.93, p = 0.02). A significant reduction in unadjusted mortality was also seen in prospective trials of post-event beta-blockade (RR 0.51, 95% CI 0.28-0.93, p = 0.03). Statistically significant differences were not seen for other outcomes investigated.

CONCLUSIONS

In adult patients with aSAH, beta-blocker therapy is associated with a mortality benefit. Studies are generally of a low quality with considerable clinical heterogeneity. Prospective large interventional trials with patient centered outcomes are required to validate this finding.

Early prediction of clinical outcomes in patients with aneurysmal subarachnoid hemorrhage using computed tomography texture analysis

Radiological evaluation of subarachnoid hemorrhage (SAH) is often subject to interobserver variability. The aim of this study was to retrospectively detect computed tomography (CT) texture parameters in the early postictal state to predict cerebral vasospasm, delayed cerebral ischemia (DCI), and functional outcome in aneurysmal SAH using quantitative CT texture analysis (CTTA) via a commercially available software program and routine CT images. 40 patients with aneurysmal SAH surgically treated at the Keio University Hospital during a four-year period were analyzed. CT texture analyses were performed using a commercially available software program (Synapse Vincent). The following texture parameters of blood clots in the subarachnoid space and cerebral edema were assessed: mean CT value, entropy, skewness, and kurtosis. The mean CT value of blood clots in the subarachnoid space was significantly associated with cerebral vasospasm, DCI, and functional outcome. The mean CT value ≥ 49.64 Hounsfield units (HU) predicted cerebral vasospasm with a sensitivity and specificity of 85.7% and 61.5%, respectively (area under the curve [AUC] = 0.758). The mean CT value ≥ 49.95 HU predicted DCI with a sensitivity and specificity of 100% and 60.6%, respectively (AUC = 0.810). The mean CT value ≥ 53.00 HU predicted poor functional outcome with a sensitivity and specificity of 56.3% and 91.7%, respectively (AUC = 0.747). CTTA using a commercially available software program demonstrated that the mean CT value of clots in the subarachnoid space in the early postictal state could predict vasospasm, DCI, and clinical outcome with a high sensitivity and specificity.

Decrease of blood flow velocity in the middle cerebral artery after stellate ganglion block following aneurysmal subarachnoid hemorrhage: a potential vasospasm treatment?

OBJECTIVE

Cerebral vasospasm (CV) is a delayed, sustained contraction of the cerebral arteries that tends to occur 3-14 days after aneurysmal subarachnoid hemorrhage (aSAH) from a ruptured aneurysm. Vasospasm potentially leads to delayed cerebral ischemia, and despite medical treatment, 1 of 3 patients suffer a persistent neurological deficit. Bedside transcranial Doppler (TCD) ultrasonography is used to indirectly detect CV through recognition of an increase in cerebral blood flow velocity (CBFV). The present study aimed to use TCD ultrasonography to monitor how CBFV changes on both the ipsi- and contralateral sides of the brain in the first 24 hours after patients have received a stellate ganglion block (SGB) to treat CV that persists despite maximum standard therapy.

METHODS

The data were culled from records of patients treated between 2013 and 2017. Patients were included if an SGB was administered following aSAH, whose CBFV was ≥ 120 cm/sec and who had either a focal neurological deficit or reduced consciousness despite having received medical treatment and blood pressure management. The SGB was performed on the side where the highest CBFV had been recorded with 8-10 ml ropivacaine 0.2%. The patient's CBFV was reassessed after 2 and 24 hours.

RESULTS

Thirty-seven patients (male/female ratio 18:19), age 17-70 years (mean age 49.9 ± 11.1), who harbored 13 clipped and 22 coiled aneurysms (1 patient received both a coil and a clip, and 3 patients had 3 untreated aneurysms) had at least one SGB. Patients received up to 4 SGBs, and thus the study comprised a total of 76 SGBs.After the first SGB, CBFV decreased in 80.5% of patients after 2 hours, from a mean of 160.3 ± 28.2 cm/sec to 127.5 ± 34.3 cm/sec (p < 0.001), and it further decreased in 63.4% after 24 hours to 137.2 ± 38.2 cm/sec (p = 0.007). A similar significant effect was found for the subsequent SGB. Adding clonidine showed no significant effect on either the onset or the duration of the SGB. Contralateral middle cerebral artery (MCA) blood flow was not reduced by the SGB.

CONCLUSIONS

To the authors' knowledge, this is the largest study on the effects of administering an SGB to aSAH patients after aneurysm rupture. The data showed a significant reduction in ipsilateral CBFV (MCA 20.5%) after SGB, lasting in about two-thirds of cases for over 24 hours with no major complications resulting from the SGB.

A Review of the Management of Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Despite decades of research, cerebral vasospasm (CV) continues to account for high morbidity and mortality in patients who survive their initial aneurysmal subarachnoid hemorrhage.

OBJECTIVE

To define the scope of the problem and review key treatment strategies that have shaped the way CV is managed in the contemporary era.

METHODS

A literature search was performed of CV management after aneurysmal subarachnoid hemorrhage.

RESULTS

Recent advances in neuroimaging have led to improved detection of vasospasm, but established treatment guidelines including hemodynamic augmentation and interventional procedures remain highly variable among neurosurgical centers. Experimental research in subarachnoid hemorrhage continues to identify novel targets for therapy.

CONCLUSIONS

Proactive and preventive strategies such as oral nimodipine and endovascular rescue therapies can reduce the morbidity and mortality associated with CV.

Predictive Value of Cerebral Autoregulation Impairment for Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis

OBJECTIVE

Delayed cerebral ischemia (DCI) happens in about 30% of patients with aneurysmal subarachnoid hemorrhage (SAH) and is related to higher mortality and disability. Some studies have shown cerebral autoregulation impairment can be a predictor of DCI in aneurysmal SAH. We conducted this meta-analysis to evaluate the predictive value of cerebral autoregulation impairment for DCI based on the current literature.

METHODS

A systematic literature search was performed in PubMed and Embase. According to inclusion and exclusion criteria, 2 authors screened the records and extracted data from the included studies. Pooled sensitivity, specificity, and their 95% confidence intervals (CIs) were obtained. To investigate the overall accuracy, a summary receiver operating characteristic (SROC) curve was built and the area under SROC curve was calculated. Deeks' linear regression was used to assess the publication bias. All statistical analyses were performed with Stata 14.0.

RESULTS

A total of 7 studies were finally included in this meta-analysis. The pooled sensitivity and specificity values of impaired cerebral autoregulation for DCI prediction were 0.79 (95% CI, 0.65-0.88) and 0.85 (95% CI, 0.615-0.96). Moreover, the area under the SROC curve of cerebral autoregulation impairment for DCI prediction was 0.87 (95% CI, 0.835-0.89). No obvious publication bias was found in Deeks' linear regression (P = 0.99).

CONCLUSIONS

Cerebral autoregulation impairment can be a helpful predictor of DCI in aneurysmal SAH. Its accuracy for DCI prediction should be verified by more studies in the future.

Medically induced hypertension, hypervolaemia and haemodilution for the treatment and prophylaxis of vasospasm following aneurysmal subarachnoid haemorrhage: systematic review

PURPOSE

Arterial vasospasm is a major cause of death and long-term disability following subarachnoid haemorrhage (SAH). The use of medically induced hypertension, hypervolaemia and/or haemodilution is widely practiced for prophylaxis and treatment of vasospasm following SAH. We aimed to determine if the quality of available research is adequate to inform use of haemodynamic management strategies to prevent or treat vasospasm following SAH.

METHODS

Individual searches of the following databases were conducted: The Cochrane Database of Systematic Reviews, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and OpenSIGLE. Pertinent randomised clinical trials and cohort studies comparing any element or combination thereof: medically induced hypertension, hypervolaemia, and haemodilution were included. Data were extracted using standardised proformas and risk of bias assessed using a domain-based risk of bias assessment tool.

RESULTS

348 study reports were identified by our literature search. Eight studies were included, three of which examined both volume expansion and medically induced hypertension. Three randomised clinical trials and two cohort studies examining prophylactic volume expansion were included. Two trials of prophylactic medically induced hypertension and two cohort studies were included. One trial and one cohort study of medically induced hypertension for treatment of established vasospasm was included. These trials demonstrated no significant difference in any of the clinical outcome measures studied. No trials of blood transfusion were included.

CONCLUSIONS

There is currently insufficient evidence to determine the efficacy or non-efficacy of intravenous volume expansion, medically induced hypertension or blood transfusion for the treatment or prophylaxis of vasospasm following SAH. All of these approaches have been associated with adverse events, of unclear incidence. The current evidence base therefore cannot be used to reliably inform clinical practice. This is a priority for further research.

Cerebral artery myogenic reactivity: The next frontier in developing effective interventions for subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating cerebral event that kills or debilitates the majority of those afflicted. The blood that spills into the subarachnoid space stimulates profound cerebral artery vasoconstriction and consequently, cerebral ischemia. Thus, once the initial bleeding in SAH is appropriately managed, the clinical focus shifts to maintaining/improving cerebral perfusion. However, current therapeutic interventions largely fail to improve clinical outcome, because they do not effectively restore normal cerebral artery function. This review discusses emerging evidence that perturbed cerebrovascular "myogenic reactivity," a crucial microvascular process that potently dictates cerebral perfusion, is the critical element underlying cerebral ischemia in SAH. In fact, the myogenic mechanism could be the reason why many therapeutic interventions, including "Triple H" therapy, fail to deliver benefit to patients. Understanding the molecular basis for myogenic reactivity changes in SAH holds the key to develop more effective therapeutic interventions; indeed, promising recent advancements fuel optimism that vascular dysfunction in SAH can be corrected to improve outcome.

Long-chain omega-3 fatty acids in aneurysmal subarachnoid hemorrhage: A randomized pilot trial of pharmaconutrition

BACKGROUND

Functional recovery after aneurysmal subarachnoid hemorrhage (SAH) remains a significant problem. We tested a novel therapeutic approach with long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) to assess the safety and feasibility of an effectiveness trial.

METHODS

We conducted a multicentre, parallel, randomized, open-label pilot trial. Patients admitted within 72 hours after SAH with modified Fisher scale scores of 3 or 4 who were selected for scheduled aneurysm clipping were allocated to receive either n-3 PUFA treatment (parenteral perioperative: 5 days; oral: 8 weeks) plus usual care or usual care alone. Exploratory outcome measures included major postoperative intracranial bleeding complications (PIBCs), cerebral infarction caused by delayed cerebral ischemia, shunt-dependent hydrocephalus, and consent rate. The computed tomography evaluator was blinded to the group assignment.

RESULTS

Forty-one patients were randomized, but one patient had to be excluded after allocation. Twenty patients remained for intention to treat analysis in each trial arm. No PIBs (95% confidence interval [CI]: 0.00 to 0.16) or other unexpected harm were observed in the intervention group (IG). No patient suspended the intervention due to side effects. There was a trend towards improvements in all benefit-related outcomes in the IG. The overall consent rate was 0.91 (95% CI: 0.78 to 0.96), and there was no consent withdrawal.

CONCLUSIONS

Although the balance between the benefit and harm of the intervention appears highly favourable, further testing on SAH patients is required. We recommend proceeding with amendments in a dose-finding trial to determine the optimal duration of parenteral treatment.

The Role of Thromboinflammation in Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is a major determinant of patient outcome following aneurysmal subarachnoid hemorrhage. Although the exact mechanisms leading to DCI are not fully known, inflammation, cerebral vasospasm, and microthrombi may all function together to mediate the onset of DCI. Indeed, inflammation is tightly linked with activation of coagulation and microthrombi formation. Thromboinflammation is the intersection at which inflammation and thrombosis regulate one another in a feedforward manner, potentiating the formation of thrombi and pro-inflammatory signaling. In this review, we will explore the role(s) of inflammation and microthrombi in subarachnoid hemorrhage (SAH) pathophysiology and DCI, and discuss the potential of targeting thromboinflammation to prevent DCI after SAH.

Xenon Reduces Neuronal Hippocampal Damage and Alters the Pattern of Microglial Activation after Experimental Subarachnoid Hemorrhage: A Randomized Controlled Animal Trial

Objective

The neuroprotective properties of the noble gas xenon have already been demonstrated using a variety of injury models. Here, we examine for the first time xenon’s possible effect in attenuating early brain injury (EBI) and its influence on posthemorrhagic microglial neuroinflammation in an in vivo rat model of subarachnoid hemorrhage (SAH).

Methods

Sprague-Dawley rats (n = 22) were randomly assigned to receive either Sham surgery (n = 9; divided into two groups) or SAH induction via endovascular perforation (n = 13, divided into two groups). Of those randomized for SAH, 7 animals were postoperatively ventilated with 50 vol% oxygen/50 vol% xenon for 1 h and 6 received 50 vol% oxygen/50 vol% nitrogen (control). The animals were sacrificed 24 h after SAH. Of each animal, a cerebral coronal section (−3.60 mm from bregma) was selected for assessment of histological damage 24 h after SAH. A 5-point neurohistopathological severity score was applied to assess neuronal cell damage in H&E and NeuN stained sections in a total of four predefined anatomical regions of interest. Microglial activation was evaluated by a software-assisted cell count of Iba-1 stained slices in three cortical regions of interest.

Results

A diffuse cellular damage was apparent in all regions of the ipsilateral hippocampus 24 h after SAH. Xenon-treated animals presented with a milder damage after SAH. This effect was found to be particularly pronounced in the medial regions of the hippocampus, CA3 (p = 0.040), and dentate gyrus (DG p = 0.040). However, for the CA1 and CA2 regions, there were no statistical differences in neuronal damage according to our histological scoring. A cell count of activated microglia was lower in the cortex of xenon-treated animals. This difference was especially apparent in the left piriform cortex (p = 0.017).

Conclusion

In animals treated with 50 vol% xenon (for 1 h) after SAH, a less pronounced neuronal damage was observed for the ipsilateral hippocampal regions CA3 and DG, when compared to the control group. In xenon-treated animals, a lower microglial cell count was observed suggesting an immunomodulatory effect generated by xenon. As for now, these results cannot be generalized as only some hippocampal regions are affected. Future studies should assess the time and localization dependency of xenon’s beneficial properties after SAH.

Amino Acids in Cerebrospinal Fluid of Patients with Aneurysmal Subarachnoid Haemorrhage: An Observational Study

Background

The authors are aware of only one article investigating amino acid concentrations in cerebrospinal fluid (CSF) in patients with ruptured intracranial aneurysms, and this was published 31 years ago. Since then, both management of subarachnoid haemorrhage (SAH) and amino acid assay techniques have seen radical alterations, yet the pathophysiology of SAH remains unclear.

Objective

To analyse the pattern of concentrations of amino acids and related compounds in patients with different outcomes following aneurysmal SAH.

Methods

49 CSF samples were collected from 23 patients on days 0–3, 5, and 10 post-SAH. Concentrations of 33 amino acids and related compounds were assayed by liquid chromatography tandem mass spectrometry in patients with good [Glasgow Outcome Scale (GOS) 1–3] and poor (GOS 4–5) outcome.

Results

Of the 33 compounds assayed, only hydroxyproline and 3-aminoisobutyric acid appeared not to increase significantly following SAH. In poor outcome patients, we found significantly higher concentrations of aspartic acid (p = 0.038), glutamic acid (p = 0.038), and seven other compounds on days 0–3 post-SAH; glutamic acid (p = 0.041) on day 5 post-SAH, and 2-aminoadipic acid (p = 0.033) on day 10 post-SAH. The most significant correlation with GOS at 3 months was found for aminoadipic acid on day 10 post-SAH (cc = −0.81).

Conclusion

Aneurysmal rupture leads to a generalised increase of amino acids and related compounds in CSF. The patterns differ between good and poor outcome cases. Increased excitatory amino acids are strongly indicative of poor outcome.

Intra-arterial vasodilators for vasospasm following aneurysmal subarachnoid hemorrhage: a meta-analysis

Objective

The efficacy of intra-arterial vasodilators (IADs) for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) remains debatable. The objective of this meta-analysis was to pool estimates of angiographic and neurological response, clinical outcome, and mortality following treatment of vasospasm with IADs.

Methods

We searched PubMed, Embase, Scopus, Clinicaltrials.gov, Cochrane database, and CINAHL in December 2015 and August 2016. Studies reporting angiographic and neurological response, clinical outcome, and mortality following IAD treatment of vasospasm in 10 or more adults with aSAH were included. All established IADs were allowed. Two authors independently selected studies and abstracted the data. Mean weighted probabilities (MWP) were calculated using random effects model.

Results

Inclusion criteria were met by 55 studies (n=1571). MWP for immediate angiographic response to IAD treatment was 89% (95% CI 83% to 94%), post-IAD neurological improvement 57% (95% CI 49% to 65%), good outcome 66% (95% CI 60% to 71%), and mortality was 9% (95% CI 7% to 12%). After adjusting for publication bias, MWP for mortality was 5% (95% CI 4% to 7%). When transcranial Doppler (TCD) was used along with clinical deterioration for patient selection, rates of neurological response (64%) and good outcome (72%) were better. IADs were not superior to controls (balloon angioplasty or medical management).

Conclusion

IAD treatment leads to a robust angiographic response and fair (but lower) rates of neurological response and good clinical outcome. Mortality was lower than the average reported in the literature. Rates of neurological response and good outcome were better when TCD was used for patient selection. Carefully designed studies are needed to compare IADs against medical management and balloon angioplasty.