Pharmacological Prevention of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH) include early brain injury and delayed neurologic deterioration, which may result from delayed cerebral ischemia (DCI). Complex pathophysiological mechanisms underlie DCI, which often includes angiographic vasospasm (aVSP) of cerebral arteries. METHODS: Despite the study of many pharmacological therapies for the prevention of DCI in aSAH, nimodipine-a dihydropyridine calcium channel blocker-remains the only drug recommended universally in this patient population. A common theme in the research of preventative therapies is the use of promising drugs that have been shown to reduce the occurrence of aVSP but ultimately did not improve functional outcomes in large, randomized studies. An example of this is the endothelin antagonist clazosentan, although this agent was recently approved in Japan. RESULTS: The use of the only approved drug, nimodipine, is limited in practice by hypotension. The administration of nimodipine and its counterpart nicardipine by alternative routes, such as intrathecally or formulated as prolonged release implants, continues to be a rational area of study. Additional agents approved in other parts of the world include fasudil and tirilazad. CONCLUSIONS: We provide a brief overview of agents currently being studied for prevention of aVSP and DCI after aSAH. Future studies may need to identify subpopulations of patients who can benefit from these drugs and perhaps redefine acceptable outcomes to demonstrate impact.

Clinical potential of automated convolutional neural network-based hematoma volumetry after aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Cerebrospinal fluid hemoglobin has been positioned as a potential biomarker and drug target for aneurysmal subarachnoid hemorrhage-related secondary brain injury (SAH-SBI). The maximum amount of hemoglobin, which may be released into the cerebrospinal fluid, is defined by the initial subarachnoid hematoma volume (ISHV). In patients without external ventricular or lumbar drain, there remains an unmet clinical need to predict the risk for SAH-SBI. The aim of this study was to explore automated segmentation of ISHV as a potential surrogate for cerebrospinal fluid hemoglobin to predict SAH-SBI. METHODS: This study is based on a retrospective analysis of imaging and clinical data from 220 consecutive patients with aneurysmal subarachnoid hemorrhage collected over a five-year period. 127 annotated initial non-contrast CT scans were used to train and test a convolutional neural network to automatically segment the ISHV in the remaining cohort. Performance was reported in terms of Dice score and intraclass correlation. We characterized the associations between ISHV and baseline cohort characteristics, SAH-SBI, ventriculoperitoneal shunt dependence, functional outcome, and survival. Established clinical (World Federation of Neurosurgical Societies, Hunt & Hess) and radiological (modified Fisher, Barrow Neurological Institute) scores served as references. RESULTS: A strong volume agreement (0.73 Dice, range 0.43 - 0.93) and intraclass correlation (0.89, 95% CI, 0.81-0.94) were shown. While ISHV was not associated with the use of antithrombotics or cardiovascular risk factors, there was strong evidence for an association with a lower Glasgow Coma Scale at hospital admission. Aneurysm size and location were not associated with ISHV, but the presence of intracerebral or intraventricular hemorrhage were independently associated with higher ISHV. Despite strong evidence for a positive association between ISHV and SAH-SBI, the discriminatory ability of ISHV for SAH-SBI was insufficient. The discriminatory ability of ISHV was, however, higher regarding ventriculoperitoneal shunt dependence and functional outcome at three-months follow-up. Multivariate survival analysis provided strong evidence for an independent negative association between survival probability and both ISHV and intraventricular hemorrhage. CONCLUSIONS: The proposed algorithm demonstrates strong performance in volumetric segmentation of the ISHV on the admission CT. While the discriminatory ability of ISHV for SAH-SBI was similar to established clinical and radiological scores, it showed a high discriminatory ability for ventriculoperitoneal shunt dependence and functional outcome at three-months follow-up.

Inhalational Versus Intravenous Anesthetic Conditioning for Subarachnoid Hemorrhage-Induced Delayed Cerebral Ischemia.

BACKGROUND: Inhalational anesthetics were associated with reduced incidence of angiographic vasospasm and delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (SAH). Whether intravenous anesthetics provide similar level of protection is not known. METHODS: Anesthetic data were collected retrospectively for patients with SAH who received general anesthesia for aneurysm repair between January 1, 2014 and May 31, 2018, at 2 academic centers in the United States (one employing primarily inhalational and the other primarily intravenous anesthesia with propofol). We compared the outcomes of angiographic vasospasm, DCI, and neurological outcome (measured by disposition at hospital discharge), between the 2 sites, adjusting for potential confounders. RESULTS: We compared 179 patients with SAH receiving inhalational anesthetics at one institution to 206 patients with SAH receiving intravenous anesthetics at the second institution. The rates of angiographic vasospasm between inhalational versus intravenous anesthetic groups were 32% versus 52% (odds ratio, 0.49 [CI, 0.32-0.75]; P=0.001) and DCI were 21% versus 40% (odds ratio, 0.47 [CI, 0.29-0.74]; P=0.001), adjusting for imbalances between sites/groups, Hunt-Hess and Fisher grades, type of aneurysm treatment, and American Society of Anesthesiology status. No impact of anesthetics on neurological outcome at time of discharge was noted with rates of good discharge outcome between inhalational versus intravenous anesthetic groups at (78% versus 72%, P=0.23). CONCLUSIONS: Our data suggest that those who received inhalational versus intravenous anesthetic for ruptured aneurysm repair had significant protection against SAH-induced angiographic vasospasm and DCI. Although we cannot fully disentangle site-specific versus anesthetic effects in this comparative study, these results, when coupled with preclinical data demonstrating a similar protective effect of inhalational anesthetics on vasospasm and DCI, suggest that inhalational anesthetics may be preferable for patients with SAH undergoing aneurysm repair. Additional investigations examining the effect of inhalational anesthetics on other SAH outcomes such as early brain injury and long-term neurological outcomes are warranted.

The HeMoVal study protocol: a prospective international multicenter cohort study to validate cerebrospinal fluid hemoglobin as a monitoring biomarker for aneurysmal subarachnoid hemorrhage related secondary brain injury.

INTRODUCTION: Preclinical studies provided a strong rationale for a pathophysiological link between cell-free hemoglobin in the cerebrospinal fluid (CSF-Hb) and secondary brain injury after subarachnoid hemorrhage (SAH-SBI). In a single-center prospective observational clinical study, external ventricular drain (EVD) based CSF-Hb proved to be a promising biomarker to monitor for SAH-SBI. The primary objective of the HeMoVal study is to prospectively validate the association between EVD based CSF-Hb and SAH-SBI during the first 14 days post-SAH. Secondary objectives include the assessment of the discrimination ability of EVD based CSF-Hb for SAH-SBI and the definition of a clinically relevant range of EVD based CSF-Hb toxicity. In addition, lumbar drain (LD) based CSF-Hb will be assessed for its association with and discrimination ability for SAH-SBI. METHODS: HeMoVal is a prospective international multicenter observational cohort study. Adult patients admitted with aneurysmal subarachnoid hemorrhage (aSAH) are eligible. While all patients with aSAH are included, we target a sample size of 250 patients with EVD within the first 14 day after aSAH. Epidemiologic and disease-specific baseline measures are assessed at the time of study inclusion. In patients with EVD or LD, each day during the first 14 days post-SAH, 2 ml of CSF will be sampled in the morning, followed by assessment of the patients for SAH-SBI, co-interventions, and complications in the afternoon. After 3 months, a clinical follow-up will be performed. For statistical analysis, the cohort will be stratified into an EVD, LD and full cohort. The primary analysis will quantify the strength of association between EVD based CSF-Hb and SAH-SBI in the EVD cohort based on a generalized additive model. Secondary analyses include the strength of association between LD based CSF-Hb and SAH-SBI in the LD cohort based on a generalized additive model, as well as the discrimination ability of CSF-Hb for SAH-SBI based on receiver operating characteristic (ROC) analyses. DISCUSSION: We hypothesize that this study will validate the value of CSF-Hb as a biomarker to monitor for SAH-SBI. In addition, the results of this study will provide the potential base to define an intervention threshold for future studies targeting CSF-Hb toxicity after aSAH. STUDY REGISTRATION: ClinicalTrials.gov Identifier NCT04998370 . Date of registration: August 10, 2021.

Serum Alkaline Phosphatase Level is Associated with Angiographic Vasospasm, Delayed Cerebral Ischemia-Caused Clinical Deterioration, and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Alkaline phosphatase (ALP) has been implicated to be associated with poor outcome in ischemic stroke patients, yet its role in aneurysmal subarachnoid hemorrhage (aSAH) patients is unknown. The current study aimed to investigate the on-admission and short-term variation trend of ALP levels in aSAH patients as well as its associations with vasospasm, delayed cerebral ischemia (DCI), and outcome after aSAH. METHODS: Between January 2014 and May 2018, all consecutive aSAH patients were prospectively enrolled. Blood samples from patients and 78 healthy individuals were obtained. Baseline information, clinical data, and radiologic data were collected, and serum ALP levels during hospitalization were measured. Patients were followed up for 6 months. RESULTS: One hundred and ninety-six aSAH patients were included. The serum ALP levels in aSAH patients were significantly higher compared to controls (71 vs. 61 U/L, p = 0.0002), yet did not differ significantly between patients with severe (WFNS 4-5) and mild clinical condition (72 vs. 63 U/L, p = 0.3362). However, ALP was significantly higher in patients with severe radiologic status (modified Fisher 3-4) compared to those with mild radiologic status (77 vs. 61.5 U/L, p = 0.0005). A significant correlation emerged between modified Fisher score and ALP level (r = 0.246, p = 0.001). Multivariable analysis found that higher ALP level was associated with angiographic vasospasm (OR 1.019, 95% CI 1.002-1.036, p = 0.026) and DCI-caused clinical deterioration (OR 1.019, 95% CI 1.001-1.037, p = 0.037), while higher WFNS score, modified Fisher score, and ALP level were independently associated with unfavorable outcome (serum ALP level, OR 1.083, 95% CI 1.041-1.127, p < 0.001). Trend analysis of ALP level based on 103 patients' data revealed a significant decrease in ALP level on post-admission day 7-9 (median; on-admission day vs. post-admission day 7-9, 72 vs. 60 U/L, p = 0.0012; post-admission day 3-5 vs. day 7-9, 70 vs. 60 U/L, p = 0.0052) and subsequent increase in ALP level on post-admission day 12-14 (median, 84 U/L, p < 0.0001). Higher ALP levels were observed in patients with unfavorable outcome on on-admission day, post-admission day 3-5, and 12-14 (median; unfavorable vs. favorable; on-admission day, 86 vs. 67 U/L, p = 0.0122; post-admission day 3-5, 80 vs. 64 U/L, p = 0.0044; post-admission day 7-9, 75 vs. 53.5 U/L, p < 0.0001) but not on post-admission day 12-14. CONCLUSIONS: Elevated serum ALP level is associated with vasospasm, DCI-caused clinical deterioration, and functional outcome after aSAH. Further studies are required to examine the potential role of serum ALP as an outcome predictor for aSAH patients.

Nimodipine prophylaxis in aneurysmal subarachnoid hemorrhage, a question of tradition or evidence: A scoping review.

BACKGROUND: The prophylactic use of nimodipine following subarachnoid hemorrhage is a practice established four decades ago when clinical management differed from current and the concept of Delayed Cerebral Ischemia (DCI) was not established. The applicability of the original studies is limited by the fact of not reflecting current practice; by utilising a dichotomised outcome measure such as good neurological outcome versus death and vegetative state; by applying variable dosing regimens and including all causes of poor neurological outcome different than DCI. This study aims to review the available evidence to discuss the ongoing role of nimodipine in contemporaneous clinical practice. METHODS: PRISMA guidelines based review, evaluated the evidence on the prophylactic use of nimodipine. The following search engines: Medline, Embase, Cochrane, Web of Science and PubMed, identified Randomized Control Trials (RCTs) with neurological benefit as outcome measure and the impact of fixed versus weight-based nimodipine dosing regimens. RESULTS: Eight RCT were selected. Three of those trials with a total of 349 patients, showed a reduction on death and vegetative state (pooled RR: 0.62; 95 % confidence interval-CI: 0.45, 0.86) related to DCI. Amongst all studies, all cause death (pooled RR = 0.73, [95 % CI: 0.56, 0.97]) favoured a fixed-dose regimen (pooled RR: 0.60; [95 % CI: 0.43, 0.85]). CONCLUSION: Available evidence demonstrates that nimodipine only reduces the risk for DCI-related death or vegetative state and that fixed-dose regimens favour all cause infarct and death independent of DCI. Contemporaneous studies assessing the benefit of nimodipine beyond death or vegetative states and applying individualized dosing are warranted.

CT Imaging Computed Tomography/Computed Tomography Angiography/Perfusion in Acute Ischemic Stroke and Vasospasm.

Computed tomography (CT), CT angiography (CTA), and CT perfusion (CTP) play crucial roles in the comprehensive evaluation and management of acute ischemic stroke, aneurysmal subarachnoid hemorrhage (SAH), and vasospasm. CTP provides functional data about cerebral blood flow, allowing radiologists, neurointerventionalists, and stroke neurologists to more accurately delineate the volume of core infarct and ischemic penumbra allowing for patient-specific treatment decisions to be made. CTA and CTP are used in tandem to evaluate for vasospasm associated with aneurysmal SAH and can help provide an insight into the physiologic impact of angiographic vasospasm, better triaging patients for medical and interventional treatment.

Clinical Burden of Angiographic Vasospasm and Its Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review.

INTRODUCTION: Angiographic vasospasm (VSP), the narrowing of intracranial arteries, is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and often results in delayed cerebral ischemia (DCI) and cerebral infarction. The objective of this systematic review was to summarize the clinical burden of angiographic VSP and its related complications (DCI and cerebral infarction) after aSAH. METHODS: Systematic searches of MEDLINE, Embase, and the Cochrane Library were conducted (in January 2021) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies reporting clinical outcomes of angiographic VSP and its related complications after aSAH. Study outcomes included measures of functional status (modified Rankin Scale [mRS], Glasgow Outcome Scale [GOS], extended Glasgow Outcome Scale [GOS-E], modified Barthel Index, or the modified National Institutes of Health Stroke Scale), cognitive status (Montreal Cognitive Assessment or the Mini Mental State Exam), clinical events (rebleeding), and mortality. Study selection, data extraction, and qualitative analyses were conducted. RESULTS: Of 5704 abstracts reviewed, 110 studies were selected: 20 comparative and 39 regression-based studies were included in the qualitative synthesis, 51 descriptive studies were excluded. Most studies (51) were observational and conducted in a single country (53). The occurrence of angiographic VSP and its related complications after aSAH resulted in significantly poorer functional outcomes in three of nine comparative and 11 of 13 regression-based studies, measured by the mRS, and in five of six comparative and eight of nine regression-based studies, measured by the GOS and GOS-E. Angiographic VSP and its related complications were significantly associated with poor cognitive status in all five regression-based studies. Numerically or significantly higher mortality rates in patients with versus those without angiographic VSP and its related complications were reported in five of ten comparative studies and in eight of nine regression-based studies. Six studies looked at specific VSP populations (e.g., by severity or timing of VSP). CONCLUSION: Patients with angiographic VSP and its related complications often had poor functional, neurological, and cognitive outcomes and reduced odds of survival both in hospital and at follow-up. We estimate that angiographic VSP and its related complications, DCI and cerebral infarction, lead to an approximately threefold higher odds of poor functional and cognitive outcomes, and about a twofold increase in the odds of death.

Aneurysmal subarachnoid hemorrhage is a medical emergency in which an aneurysm, a weakened outpouching of a cerebral blood vessel, ruptures causing bleeding in the subarachnoid space. Components from the bleeding can trigger a process leading to the constriction of cerebral arteries, called angiographic vasospasm. Angiographic vasospasm is a frequent occurrence after aneurysmal subarachnoid hemorrhage and can also result in delayed cerebral ischemia and cerebral infarction, which can severely impact patients' health. This study summarizes the published literature to describe the clinical burden that patients may experience due to angiographic vasospasm, delayed cerebral ischemia, and cerebral infarction after aneurysmal subarachnoid hemorrhage. The evidence from these studies emphasizes numerous clinical consequences that patients may experience. These patients may suffer from diminished neurological and intellectual activity, leading to disability and a loss of functional independence in everyday activities. Angiographic vasospasm and its related complications also reduce the chances of survival, both in the hospital and at follow-up. The considerable clinical burden associated with angiographic vasospasm, delayed cerebral ischemia, and cerebral infarction highlights the importance of their prevention.

Alcohol Abuse Associated With Increased Risk of Angiographic Vasospasm and Delayed Cerebral Ischemia in Patients With Aneurysmal Subarachnoid Hemorrhage Requiring Mechanical Ventilation.

Objective: Although alcohol abuse has been indicated to cause cerebral aneurysm development and rupture, there is limited data on the impact of alcohol abuse on outcomes after an aneurysmal subarachnoid hemorrhage (aSAH). This study aims to investigate whether alcohol abuse increases the risk of angiographic vasospasm and delayed cerebral ischemia (DCI) in critically ill patients with aSAH. Methods: We conducted a secondary analysis based on a retrospective study in a French university hospital intensive care unit (ICU). Patients with aSAH requiring mechanical ventilation hospitalized between 2010 and 2015 were included. Patients were segregated according to alcohol abuse (yes or no). Multivariable logistic regression analysis was used to identify the independent risk factors associated with angiographic vasospasm and DCI. Results: The patient proportion of alcohol abuse was dramatically greater in males than that in females (p < 0.001). The Simplified Acute Physiology Score II (SAPSII) score on admission did not show a statistical difference. Neither did the World Federation of Neurosurgical Societies (WFNS) and Fisher scores. Patients with alcohol abuse were more likely to develop angiographic vasospasm (OR 3.65, 95% CI 1.17-11.39; p = 0.0260) and DCI (OR 3.53, 95% CI 1.13-10.97; p = 0.0294) as evidenced by multivariable logistic regression analysis. Conclusions: In this study, patients with alcohol abuse are at higher odds of angiographic vasospasm and DCI, which are related to poor prognosis following aSAH. These findings are important for the prevention and clinical management of aSAH.

Associations Between Transcranial Doppler Vasospasm and Clinical Outcomes After Aneurysmal Subarachnoid Hemorrhage: A Retrospective Observational Study.

OBJECTIVE: The objective is to examine the relationship between transcranial Doppler cerebral vasospasm (TCD-vasospasm), and clinical outcomes in aneurysmal subarachnoid hemorrhage (aSAH). METHODS: In a retrospective cohort study, using univariate and multivariate analysis, we examined the association between TCD-vasospasm (defined as Lindegaard ratio >3) and patient's ability to ambulate without assistance, the need for tracheostomy and gastrostomy tube placement, and the likelihood of being discharged home from the hospital. RESULTS: We studied 346 patients with aSAH; median age 55 years (Interquartile range IQR 46,64), median Hunt and Hess 3 [IQR 1-5]. Overall, 68.6% (n=238) had TCD-vasospasm, and 28% (n=97) had delayed cerebral ischemia. At hospital discharge, 54.3% (n=188) were able to walk without assistance, 5.8% (n=20) had received a tracheostomy, and 12% (n=42) had received a gastrostomy tube. Fifty-three percent (n=183) were discharged directly from the hospital to their home. TCD-vasospasm was not associated with ambulation without assistance at discharge (adjusted odds ratio, aOR 0.54, 95% 0.19,1.45), tracheostomy placement (aOR 2.04, 95% 0.23,18.43), gastrostomy tube placement (aOR 0.95, 95% CI 0.28,3.26), discharge to home (aOR 0.36, 95% CI 0.11,1.23). CONCLUSION: This single-center retrospective study finds that TCD-vasospasm is not associated with clinical outcomes such as ambulation without assistance, discharge to home from the hospital, tracheostomy, and gastrostomy feeding tube placement. Routine screening for cerebral vasospasm and its impact on vasospasm diagnostic and therapeutic interventions and their associations with improved clinical outcomes warrant an evaluation in large, prospective, case-controlled, multi-center studies.

Conditioning Effect of Inhalational Anesthetics on Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) has been identified as an independent predictor of poor outcome in numerous studies. OBJECTIVE: To investigate the potential protective role of inhalational anesthetics against angiographic vasospasm, DCI, and neurologic outcome in SAH patients. METHODS: After Institutional Review Board approval, data were collected retrospectively for SAH patients who received general anesthesia for aneurysm repair between January 1st, 2010 and May 31st, 2018. Primary outcomes were angiographic vasospasm, DCI, and neurologic outcome as measured by modified Rankin scale at hospital discharge. Univariate and logistic regression analysis were performed to identify independent predictors of these outcomes. RESULTS: The cohort included 390 SAH patients with an average age of 56 ± 15 (mean ± SD). Multivariate logistic regression analysis identified inhalational anesthetic only technique, Hunt-Hess grade, age, anterior circulation aneurysm and average intraoperative mean blood pressure as independent predictors of angiographic vasospasm. Inhalational anesthetic only technique and modified Fishers grade were identified as independent predictors of DCI. No impact on neurological outcome at time of discharge was noted. CONCLUSION: Our data provide additional evidence that inhalational anesthetic conditioning in SAH patients affords protection against angiographic vasospasm and new evidence that it exerts a protective effect against DCI. When coupled with similar results from preclinical studies, our data suggest further investigation into the impact of inhalational anesthetic conditioning on SAH patients, including elucidating the most effective dosing regimen, defining the therapeutic window, determining whether a similar protective effect against early brain injury, and on long-term neurological outcome exists.

Effects of Various Therapeutic Agents on Vasospasm and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage-Results of a Network Meta-Analysis.

BACKGROUND: Vasospasm and delayed ischemic neurologic deficits are the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Several therapeutic agents have been assessed in randomized controlled trials for their efficacy in reducing the incidence of vasospasm and improving functional outcome. The aim of this network meta-analysis is to compare all these therapeutic agents for their effect on functional outcome and other parameters after aSAH. METHODS: A comprehensive search of different databases was performed to retrieve randomized controlled trials describing the effect of various therapeutic approaches on functional outcome and other parameters after aSAH. RESULTS: Ninety-two articles were selected for full text review and 57 articles were selected for the final analysis. Nicardipine prolonged-release implants were found to be the best treatment in terms of favorable outcome (odds ratio [OR], 8.55; 95% credible interval [CrI], 1.63-56.71), decreasing mortality (OR, 0.08; 95% CrI, 0-0.82), and preventing angiographic vasospasm (OR, 0.018; 95% CrI, 0.00057-0.16). Cilostazol was found to be the second-best treatment in improving favorable outcomes (OR, 3.58; 95% CrI, 1.97-6.57) and decreasing mortality (OR, 0.41; 95% CrI, 0.12-1.15). Fasudil (OR, 0.16; 95% CrI, 0.03-0.78) was found to be the best treatment in decreasing increased vessel velocity and enoxaparin (OR, 0.25; 95% CrI, 0.057-1.0) in preventing delayed ischemic neurologic deficits. CONCLUSIONS: Our analysis showed that nicardipine prolonged-release implants and cilostazol were associated with the best chance of improving favorable outcome and mortality in patients with aSAH. However, larger multicentric studies from other parts of the world are required to confirm these findings.

Neurovascular disease, diagnosis, and therapy: Subarachnoid hemorrhage and cerebral vasospasm.

The worldwide incidence of spontaneous subarachnoid hemorrhage is about 6.1 per 100,000 cases per year (Etminan et al., 2019). Eighty-five percent of cases are due to intracranial aneurysms. The mean age of those affected is 55 years, and two-thirds of the patients are female. The prognosis is related mainly to the neurologic condition after the subarachnoid hemorrhage and the age of the patient. Overall, 15% of patients die before reaching the hospital, another 20% die within 30 days, and overall 75% are dead or remain disabled. Case fatality has declined by 17% over the last 3 decades. Despite the improvement in outcome probably due to improved diagnosis, early aneurysm repair, administration of nimodipine, and advanced intensive care support, the outcome is not very good. Even among survivors, 75% have permanent cognitive deficits, mood disorders, fatigue, inability to return to work, and executive dysfunction and are often unable to return to their premorbid level of functioning. The key diagnostic test is computed tomography, and the treatments that are most strongly supported by scientific evidence are to undertake aneurysm repair in a timely fashion by endovascular coiling rather than neurosurgical clipping when feasible and to administer enteral nimodipine. The most common complications are aneurysm rebleeding, hydrocephalus, delayed cerebral ischemia, and medical complications (fever, anemia, and hyperglycemia). Management also probably is optimized by neurologic intensive care units and multidisciplinary teams.

Cerebrospinal fluid hemoglobin drives subarachnoid hemorrhage-related secondary brain injury.

Secondary brain injury after aneurysmal subarachnoid hemorrhage (SAH-SBI) contributes to poor outcomes in patients after rupture of an intracranial aneurysm. The lack of diagnostic biomarkers and novel drug targets represent an unmet need. The aim of this study was to investigate the clinical and pathophysiological association between cerebrospinal fluid hemoglobin (CSF-Hb) and SAH-SBI. In a cohort of 47 patients, we collected daily CSF-samples within 14 days after aneurysm rupture. There was very strong evidence for a positive association between spectrophotometrically determined CSF-Hb and SAH-SBI. The accuracy of CSF-Hb to monitor for SAH-SBI markedly exceeded that of established methods (AUC: 0.89 [0.85-0.92]). Temporal proteome analysis revealed erythrolysis accompanied by an adaptive macrophage response as the two dominant biological processes in the CSF-space after aneurysm rupture. Ex-vivo experiments on the vasoconstrictive and oxidative potential of Hb revealed critical inflection points overlapping CSF-Hb thresholds in patients with SAH-SBI. Selective depletion and in-solution neutralization by haptoglobin or hemopexin efficiently attenuated the vasoconstrictive and lipid peroxidation activities of CSF-Hb. Collectively, the clinical association between high CSF-Hb levels and SAH-SBI, the underlying pathophysiological rationale, and the favorable effects of haptoglobin and hemopexin in ex-vivo experiments position CSF-Hb as a highly attractive biomarker and potential drug target.

Cerebral Vasospasm After Spontaneous Subarachnoid Hemorrhage: Angiographic Pattern and Its Impact on the Clinical Course.

OBJECTIVE: To analyze angiographic characteristics of cerebral vasospasm (CVS) after spontaneous subarachnoid hemorrhage (sSAH) and their potential impact on secondary infarction and functional outcome. METHODS: Demographic, clinical, and imaging data of sSAH patients with angiographic CVS admitted over a 6-year period were retrospectively analyzed. RESULTS: A total of 85 patients were included in the final analysis. A total of 311 arterial territories in 85 angiographies demonstrated angiographic CVS. The anterior cerebral artery (ACA) was the most common site of angiographic CVS (42.1%), followed by the middle cerebral artery (MCA) (26.7%). In 29 angiographies (34%) CVS was found in more than 3 vessels and a bilateral pattern was identified in 53 cases (62%). Older age (OR 3.24 [95% CI 1.30-8.07], P = 0.012) was identified as the only significant risk factor for CVS-related infarction (OR 22.67, P = 0.015). Unfavorable outcome was associated with older age (OR 3.24, P = 0.023) and poor World Federation of Neurosurgical Societies grade (OR 3.64, P = 0.015). Analyses of angiographic characteristics did not reveal any risk factors for unfavorable outcome. We identified distal CVS as a significant risk factor for CVS-related infarction (OR 2.89, P = 0.026). CONCLUSIONS: Angiographic CVS after sSAH shows a specific distribution pattern in favor of ACA and MCA and in most cases 2-3 affected vessels are affected, often bilaterally. Patients exhibiting distal CVS have a higher risk for CVS-related infarction and should be observed closely. Nonetheless, the majority of angiographic characteristics did not allow conclusions about functional outcome nor the occurrence of CVS-related infarction in sSAH patients.

Comparison of radiological versus clinical cerebral vasospasm after aneurysmal subarachnoid hemorrhage: is vasospasm always present?

OBJECTIVES: Radiological and clinical cerebral vasospasm (CV) is defined either as a delayed narrowing of cerebral arteries after aneurysmal subarachnoid hemorrhage (aSAH) or/and occurrence of new neurological deficit/worsening of Modified Glasgow coma score for 2 or more points. The objective of this study is to determine the presence and correlation between clinical and radiological presence of vasospasm in patients with aSAH. METHODS: This study was designed as a clinical, prospective single center study at the Clinic of Neurosurgery, Clinical Center of Vojvodina, Novi Sad, Serbia. A total of 50 patients was included in the study after having radiologically confirmed aSAH. Intensity and region of CV was determined by CT and CTA performed both on admission and on day 9 of hospitalization, except for cases where clinical protocol required earlier imaging due to occurrence of clinical signs and symptoms of CV. In all patients, values of arterial blood pressure (PABP), headache (HA), body temperature (PBT), nonspecific behaviors (NSB), deterioration of consciousness (DC), new neurological deficit (NND), deterioration of two points or more per modified Glasgow Coma Scale (DmGCS ≥ 2) were monitored. RESULTS: CTA showed angiographic vasospasm detected in 100% patients with aSAH. Statistically significant positive correlation was found between the intensity of radiological CV and appearance of NND and DmGCS ≥ 2. CONCLUSIONS: This study confirms that CV always follows aSAH. Future research into pathophysiology of CV is needed in order to determine exact treatment strategies and targets so treatment towards zero mortality can be achieved.

Lessons from the CONSCIOUS-1 Study.

After years of research on treatment of aneurysmal subarachnoid hemorrhage (aSAH), including randomized clinical trials, few treatments have been shown to be efficacious. Nevertheless, reductions in morbidity and mortality have occurred over the last decades. Reasons for the improved outcomes remain unclear. One randomized clinical trial that has been examined in detail with these questions in mind is Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1). This was a phase-2 trial testing the effect of clazosentan on angiographic vasospasm (aVSP) in patients with aSAH. Clazosentan decreased moderate to severe aVSP. There was no statistically significant effect on the extended Glasgow outcome score (GOS), although the study was not powered for this endpoint. Data from the approximately 400 patients in the study were detailed, rigorously collected and documented and were generously made available to one investigator. Post-hoc analyses were conducted which have expanded our knowledge of the management of aSAH. We review those analyses here.

Evidence for a conditioning effect of inhalational anesthetics on angiographic vasospasm after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) is characterized by large-artery vasospasm, distal autoregulatory dysfunction, cortical spreading depression, and microvessel thrombi. Large-artery vasospasm has been identified as an independent predictor of poor outcome in numerous studies. Recently, several animal studies have identified a strong protective role for inhalational anesthetics against secondary brain injury after SAH including DCI-a phenomenon referred to as anesthetic conditioning. The aim of the present study was to assess the potential role of inhalational anesthetics against cerebral vasospasm and DCI in patients suffering from an SAH. METHODS: After IRB approval, data were collected retrospectively for all SAH patients admitted to the authors' hospital between January 1, 2010, and December 31, 2013, who received general anesthesia with either inhalational anesthetics only (sevoflurane or desflurane) or combined inhalational (sevoflurane or desflurane) and intravenous (propofol) anesthetics during aneurysm treatment. The primary outcomes were development of angiographic vasospasm and development of DCI during hospitalization. Univariate and logistic regression analyses were performed to identify independent predictors of these endpoints. RESULTS: The cohort included 157 SAH patients whose mean age was 56 ± 14 (± SD). An inhalational anesthetic-only technique was employed in 119 patients (76%), while a combination of inhalational and intravenous anesthetics was employed in 34 patients (22%). As expected, patients in the inhalational anesthetic-only group were exposed to significantly more inhalational agent than patients in the combination anesthetic group (p < 0.05). Multivariate logistic regression analysis identified inhalational anesthetic-only technique (OR 0.35, 95% CI 0.14-0.89), Hunt and Hess grade (OR 1.51, 95% CI 1.03-2.22), and diabetes (OR 0.19, 95% CI 0.06-0.55) as significant predictors of angiographic vasospasm. In contradistinction, the inhalational anesthetic-only technique had no significant impact on the incidence of DCI or functional outcome at discharge, though greater exposure to desflurane (as measured by end-tidal concentration) was associated with a lower incidence of DCI. CONCLUSIONS: These data represent the first evidence in humans that inhalational anesthetics may exert a conditioning protective effect against angiographic vasospasm in SAH patients. Future studies will be needed to determine whether optimized inhalational anesthetic paradigms produce definitive protection against angiographic vasospasm; whether they protect against other events leading to secondary brain injury after SAH, including microvascular thrombi, autoregulatory dysfunction, blood-brain barrier breakdown, neuroinflammation, and neuronal cell death; and, if so, whether this protection ultimately improves patient outcome.