Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis

Comparison of scales for the evaluation of aneurysmal subarachnoid haemorrhage: a retrospective cohort study

BACKGROUND/OBJECTIVES

Aneurysmal subarachnoid haemorrhage (aSAH) is a life-threatening event with major complications. Delayed cerebral infarct (DCI) occurs most frequently 7 days after aSAH and can last for a prolonged period. To determine the most predictive radiological scales in grading subarachnoid or ventricular haemorrhage or both for functional outcome at 3 months in a large aSAH population, we conducted a single-centre retrospective study.

METHODS

A 3-year single-centre retrospective cohort study of 230 patients hospitalised for aSAH was analysed. Initial computed tomography (CT) scans in patients hospitalised for aSAH were blindly assessed using eight grading systems: the Fisher grade, modified Fisher grade, Barrow Neurological Institute scale, Hijdra scale, Intraventricular Haemorrhage (IVH) score, Graeb score and LeRoux score.

RESULTS

Of 200 patients with aSAH who survived to day 7 and were included for DCI analysis, 39% of cases were complicated with DCI. The Hijdra scale was the best predictor for DCI, with a receiver operating characteristic area under the curve (ROCAUC) of 0.80 (95% confidence interval (CI), 0.74-0.85). The IVH score was the most effective grading system for predicting acute hydrocephalus, with a ROCAUC of 0.85 (95% CI, 0.79-0.89). In multivariate analysis, the Hijdra scale was the best predictor of the occurrence of DCI (hazard ratio, 1.18; 95% CI, 1.10-1.25).

CONCLUSIONS

Although these results have yet to be prospectively confirmed, our findings suggest that the Hijdra scale may be a good predictor of DCI and could be useful in daily clinical practice.

CLINICAL RELEVANCE STATEMENT

Better assessment of subarachnoid haemorrhage patients would allow for better prognostication and management of expectations, as well as referral for appropriate services and helping to appropriate use limited critical care resources.

KEY POINTS

Aneurysmal subarachnoid haemorrhage is a life-threatening event that causes severe disability and leads to major complications such as delayed cerebral infarction. Accurate assessment of the amount of blood in the subarachnoid spaces on computed tomography with the Hijdra scale can better predict the risk of delayed cerebral infarct. The Hijdra scale could be a good triage tool for subarachnoid haemorrhage patients.

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

All Three Supersystems-Nervous, Vascular, and Immune-Contribute to the Cortical Infarcts After Subarachnoid Hemorrhage

The recently published DISCHARGE-1 trial supports the observations of earlier autopsy and neuroimaging studies that almost 70% of all focal brain damage after aneurysmal subarachnoid hemorrhage are anemic infarcts of the cortex, often also affecting the white matter immediately below. The infarcts are not limited by the usual vascular territories. About two-fifths of the ischemic damage occurs within ~ 48 h; the remaining three-fifths are delayed (within ~ 3 weeks). Using neuromonitoring technology in combination with longitudinal neuroimaging, the entire sequence of both early and delayed cortical infarct development after subarachnoid hemorrhage has recently been recorded in patients. Characteristically, cortical infarcts are caused by acute severe vasospastic events, so-called spreading ischemia, triggered by spontaneously occurring spreading depolarization. In locations where a spreading depolarization passes through, cerebral blood flow can drastically drop within a few seconds and remain suppressed for minutes or even hours, often followed by high-amplitude, sustained hyperemia. In spreading depolarization, neurons lead the event, and the other cells of the neurovascular unit (endothelium, vascular smooth muscle, pericytes, astrocytes, microglia, oligodendrocytes) follow. However, dysregulation in cells of all three supersystems-nervous, vascular, and immune-is very likely involved in the dysfunction of the neurovascular unit underlying spreading ischemia. It is assumed that subarachnoid blood, which lies directly on the cortex and enters the parenchyma via glymphatic channels, triggers these dysregulations. This review discusses the neuroglial, neurovascular, and neuroimmunological dysregulations in the context of spreading depolarization and spreading ischemia as critical elements in the pathogenesis of cortical infarcts after subarachnoid hemorrhage.

The value of modified hijdra score in patients with aneurysmal subarachnoid hemorrhage

Background

The complexity of calculating the Hijdra score has limited its clinical utility in aiding the diagnosis of intracranial ruptured aneurysms.

Objective

This study aimed to investigate the diagnostic and prognostic value of the modified Hijdra score in patients with aneurysmal subarachnoid hemorrhage (aSAH).

Methods

Data from 773 patients with subarachnoid hemorrhage (SAH) at the First People's Hospital of Lianyungang from January 2018 to June 2023 were collected. The modified Hijdra scoring method simplifies the assessment of 10 basal cisterns/cisterns fissures compared to the traditional scoring method, with scores ranging from 0 to 2 for each item, and assigns specific scores to hematomas larger than 1 cm in diameter. The data were divided into an evaluation group (n = 641) and a validation group (n = 132). In the evaluation group, the performance of the modified Hijdra score in diagnosis and prognostic prediction was assessed, while the diagnostic and prognostic prediction efficacy of the modified Hijdra method was evaluated using the validation set.

Results

Among the 641 patients in the evaluation group,550 (85. 8%) were diagnosed with intracranial aneurysms. The modified Hijdra score demonstrated an AUC of 0. 894 for aneurysm diagnosis, with a sensitivity of 98. 0% and a specificity of 64. 8% at a CutOff value of 7. 5. The diagnostic efficacy of the modified Hijdra score was 93. 24%, with a negative predictive value of 84. 29%, while the Hijdra score 's diagnostic efficacy was 85. 34% with a negative predictive value of 48. 89%. The AUC of the modified Hijdra score for predicting prognosis in patients with aneurysms was 0. 824, with a sensitivity of 84. 3% and a specificity of 70. 0% at a CutOff value of 16. 5. In CTA-negative patients, the modified Hijdra score was significantly higher (P < 0. 0001) in patients with aneurysmal SAH (15. 48 ± 3. 93) compared to those with non-aneurysmal SAH (6. 31 ± 4. 52).

Conclusions

The modified Hijdra score is a valuable tool for assisting in the diagnosis and prognosis prediction of aneurysmal subarachnoid hemorrhage.

Differential DNA methylation associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: a systematic review

Recent studies suggest that differential DNA methylation could play a role in the mechanism of cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Considering the significance of this matter and a lack of effective prophylaxis against DCI, we aim to summarize the current state of knowledge regarding their associations with DNA methylation and identify the gaps for a future trial. PubMed MEDLINE, Scopus, and Web of Science were searched by two authors in three waves for relevant DNA methylation association studies in DCI after aSAH. PRISMA checklist was followed for a systematic structure. STROBE statement was used to assess the quality and risk of bias within studies. This research was funded by the National Science Centre, Poland (grant number 2021/41/N/NZ2/00844). Of 70 records, 7 peer-reviewed articles met the eligibility criteria. Five studies used a candidate gene approach, three were epigenome-wide association studies (EWAS), one utilized bioinformatics of the previous EWAS, with two studies using more than one approach. Methylation status of four cytosine-guanine dinucleotides (CpGs) related to four distinct genes (ITPR3, HAMP, INSR, CDHR5) have been found significantly or suggestively associated with DCI after aSAH. Analysis of epigenetic clocks yielded significant association of lower age acceleration with radiological CVS but not with DCI. Hub genes for hypermethylation (VHL, KIF3A, KIFAP3, RACGAP1, OPRM1) and hypomethylation (ALB, IL5) in DCI have been indicated through bioinformatics analysis. As none of the CpGs overlapped across the studies, meta-analysis was not applicable. The identified methylation sites might potentially serve as a biomarker for early diagnosis of DCI after aSAH in future. However, a lack of overlapping results prompts the need for large-scale multicenter studies. Challenges and prospects are discussed.

Stroke Unit as an alternative to Intensive Care Unit for initial hospital admission of low-grade non-aneurysmal subarachnoid haemorrhage: A safety and cost-minimisation analysis

INTRODUCTION

Stroke Units (SU) have been suggested as an alternative to Intensive Care units (ICU) for initial admission of low-grade non-aneurysmal spontaneous subarachnoid haemorrhage (naSAH). We hypothesised that the incidence of in-hospital complications and long-term clinical outcomes in low-grade naSAH patients would be comparable in both settings, and that a cost-minimisation analysis would favour the use of SU.

PATIENTS AND METHODS

Retrospective, single-centre study at a third-level stroke-referral hospital, including low-grade spontaneous naSAH patients with WFNS 1-2. Primary outcomes were death and functional status at 3 months. Secondary outcomes were incidence of in-hospital major neurological and systemic complications. Additionally, a cost-minimisation analysis was conducted to estimate the average cost savings that could be achieved with the most efficient approach.

RESULTS

Out of 96 naSAH patients, 30 (31%) were initially admitted to ICU and 66 (69%) to SU. Both groups had similar demographic and radiological features except for a higher proportion of WFNS 2 in ICU subgroup. There were no statistically significant differences between ICU and SU-managed subgroups in death rate (2 (7%) and 1 (2%), respectively), functional outcome at 90 days (28 (93%) and 61 (92%) modified Rankin Scale 0-2) or neurological and systemic in-hospital complications. Cost-minimisation analysis demonstrated significant monetary savings favouring the SU strategy.

DISCUSSION AND CONCLUSION

Initial admission to the SU appears to be a safe and cost-effective alternative to the ICU for low-grade naSAH patients, with comparable clinical outcomes and a reduction of hospitalisation-related costs. Prospective multicenter randomised studies are encouraged to further evaluate this approach.

Proposed imaging assessment score for aneurysmal subarachnoid hemorrhage correlated with prognosis: Shinshu Aneurysmal subarachnoid hemorrhage score

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) imaging has been shown to correlate with prognosis. However, no numerical index of bleeding severity has been established. This study aimed to propose a new simple scoring system for computed tomography imaging of aSAH and to confirm its effectiveness in retrospective and prospective studies.

METHODS

We devised an image evaluation system as an objective index. This system was established by scoring six items, with a maximum total of 19 points. Using this score, named the Shinshu Aneurysmal Subarachnoid Hemorrhage Score (S-score), we performed a retrospective study of 210 patients with aSAH at a single institution to confirm its efficacy. Age and World Federation of Neurosurgical Societies grades were adopted as other verification items, and the modified Rankin Scale was used for prognostic evaluation. A multicenter prospective study was then conducted to examine the function of the score by examining 214 patients with aSAH.

RESULTS

In the retrospective study, the threshold of the S-score between good and poor prognoses was 9/19 points. The area under the curve by receiver operating characteristic analysis of the S-score was 0.819, suggesting efficacy, with an odds ratio (OR) of 1.291 (1.077-1.547). In the prospective study, the judgment capability of the S-score was evaluated with a sensitivity of 0.674, specificity of 0.881, positive predictive value of 0.789, negative predictive value of 0.804, false-positive ratio of 0.119, false-negative ratio of 0.325, positive likelihood ratio of 6.072, and negative likelihood ratio of 1.369. S-score showed a significant difference in prognosis. The OR was 1.183 (1.009-1.388).

CONCLUSIONS

The scoring system could contribute to patient prognosis assessment. S-score and its prognostic formulas may serve as an objective source of information in the development of clinical medicine.

Trends in Delayed Cerebral Ischemia After Subarachnoid Hemorrhage Over Past 10 years: A Bibliometric Analysis

BACKGROUND

As a common hemorrhagic cerebrovascular disease, subarachnoid hemorrhage (SAH) has high mortality and disability. Delayed cerebral ischemia (DCI) is among the major complications after SAH, severely affecting the patient prognosis. Through bibliometric analysis, this study investigated the global research status, trends, and hotspots of DCI after SAH from 2013 to 2022, providing a scientific reference for researchers in this field.

METHODS

We searched the Web of Science Core Collection for articles and associated records from 2013 to 2022. The data were analyzed and presented using VOSviewer software.

RESULTS

This study covered 3436 articles, and the number of publications issued by DCI after SAH study increased annually. The United States published the most papers and had the highest number of citations. Harvard University and World Neurosurgery were the institutions and journals with the most published papers. Keyword analysis indicated that the recent research on DCI after SAH has focused on its pathophysiological mechanisms.

CONCLUSIONS

DCI after SAH has drawn increasing interest in academic circles during the past decade. This study presented an objective, systematic, and comprehensive analysis of the literature on DCI after SAH. Currently, the hotspots in this field focus on pathophysiological mechanisms.

The Role of Cisternostomy and Cisternal Drainage in the Treatment of Aneurysmal Subarachnoid Hemorrhage: A Comprehensive Review

Aneurysmal subarachnoid hemorrhage (aSAH) provokes a cascade reaction that is responsible for early and delayed brain injuries mediated by intracranial hypertension, hydrocephalus, cerebral vasospasm (CV), and delayed cerebral ischemia (DCI), which result in increased morbidity and mortality. During open microsurgical repair, cisternal access is achieved essentially to gain proximal vascular control and aneurysm exposition. Cisternostomy also allows brain relaxation, removal of cisternal clots, and restoration of the CSF dynamics through the communication between the anterior and posterior circulation cisterns and the ventricular system, with the opening of the Membrane of Liliequist and lamina terminalis, respectively. Continuous postoperative CSF drainage through a cisternal drain (CD) is a valuable option for treating acute hydrocephalus and intracranial hypertension. Moreover, it efficiently removes the blood and toxic degradation products, with a potential benefit on CV, DCI, and shunt-dependent hydrocephalus. Finally, the CD is an effective pathway to administer vasoactive, fibrinolytic, and anti-oxidant agents and shows promising results in decreasing CV and DCI rates while minimizing systemic effects. We performed a comprehensive review to establish the adjuvant role of cisternostomy and CD performed in cases of direct surgical repair for ruptured intracranial aneurysms and their role in the prevention and treatment of aSAH complications.

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.

Prognostic Neuroimaging Biomarkers in Acute Vascular Brain Injury and Traumatic Brain Injury

Prognostic imaging biomarkers after acute brain injury inform treatment decisions, track the progression of intracranial injury, and can be used in shared decision-making processes with families. Herein, key established biomarkers and prognostic scoring systems are surveyed in the literature, and their applications in clinical practice and clinical trials are discussed. Biomarkers in acute ischemic stroke include computed tomography (CT) hypodensity scoring, diffusion-weighted lesion volume, and core infarct size on perfusion imaging. Intracerebral hemorrhage biomarkers include hemorrhage volume, expansion, and location. Aneurysmal subarachnoid biomarkers include hemorrhage grading, presence of diffusion-restricting lesions, and acute hydrocephalus. Traumatic brain injury CT scoring systems, contusion expansion, and diffuse axonal injury grading are reviewed. Emerging biomarkers including white matter disease scoring, diffusion tensor imaging, and the automated calculation of scoring systems and volumetrics are discussed.

A systematic review on intracranial aneurysm and hemorrhage detection using machine learning and deep learning techniques

The risk of discovering an intracranial aneurysm during the initial screening and follow-up screening are reported as around 11%, and 7% respectively (Zuurbie et al., 2023) to these mass effects, unruptured aneurysms frequently generate symptoms, however, the real hazard occurs when an aneurysm ruptures and results in a cerebral hemorrhage known as a subarachnoid hemorrhage. The objective is to study the multiple kinds of hemorrhage and aneurysm detection problems and develop machine and deep learning models to recognise them. Due to its early stage, subarachnoid hemorrhage, the most typical symptom after aneurysm rupture, is an important medical condition. It frequently results in severe neurological emergencies or even death. Although most aneurysms are asymptomatic and won't burst, because of their unpredictable growth, even small aneurysms are susceptible. A timely diagnosis is essential to prevent early mortality because a large percentage of hemorrhage cases present can be fatal. Physiological/imaging markers and the degree of the subarachnoid hemorrhage can be used as indicators for potential early treatments in hemorrhage. The hemodynamic pathomechanisms and microcellular environment should remain a priority for academics and medical professionals. There is still disagreement about how and when to care for aneurysms that have not ruptured despite studies reporting on the risk of rupture and outcomes. We are optimistic that with the progress in our understanding of the pathophysiology of hemorrhages and aneurysms and the advancement of artificial intelligence has made it feasible to conduct analyses with a high degree of precision, effectiveness and reliability.

The Role of Early Serum Biomarkers and Clinical Rating Scales in the Prediction of Delayed Cerebral Ischaemia and Short-Term Outcome after Aneurysmal Subarachnoid Haemorrhage: Single Centre Experience

Considering the variety of complications that arise after aneurysmal subarachnoid haemorrhage (aSAH) and the complex pathomechanism of delayed cerebral ischaemia (DCI), the task of predicting the outcome assumes a profound complexity. Therefore, there is a need to develop early predictive and decision-making models. This study explores the effect of serum biomarkers and clinical scales on patients' outcomes and their interrelationship with DCI and systemic complications in aSAH. This was a retrospective analysis including aSAH patients admitted to the Wroclaw University Hospital (Wrocław, Poland) from 2011 to 2020. A good outcome was defined as a modified Rankin Scale (mRS) score of 0-2. The prediction of the development of DCI and poor outcome was conducted using logistic regression as a standard model (SM) and random forest as a machine learning method (ML). A cohort of 174 aSAH patients were included in the analysis. DCI was diagnosed in 79 (45%) patients. Significant differences between patients with poor vs. good outcome were determined from their levels of albumin (31 ± 7 vs. 35 ± 5 (g/L); p < 0.001), D-dimer (3.0 ± 4.5 vs. 1.5 ± 2.8 (ng/mL); p < 0.001), procalcitonin (0.2 ± 0.4 vs. 0.1 ± 0.1 (ng/mL); p < 0.001), and glucose (169 ± 69 vs. 137 ± 48 (nmol/L); p < 0.001). SM for DCI prediction included the Apache II scale (odds ratio [OD] 1.05; 95% confidence interval [CI] 1.00-1.09) and albumin level (OD 0.88; CI 0.82-0.95). ML demonstrated that low albumin level, high Apache II scale, increased D-dimer and procalcitonin levels had the highest predictive values for DCI. The integration of clinical parameters and scales with a panel of biomarkers may effectively facilitate the stratification of aSAH patients, identifying those at high risk of secondary complications and poor outcome.

Comparing radiographic scores for prediction of complications and outcome of aneurysmal subarachnoid hemorrhage: Which performs best?

BACKGROUND AND PURPOSE

Aneurysmal subarachnoid hemorrhage (aSAH) is characterized by high morbidity and mortality proceeding from the initial severity and following complications of aSAH. Various scores have been developed to predict these risks. We aimed to analyze the clinical value of different radiographic scores for prognostication of aSAH outcome.

METHODS

Initial computed tomography scans (≤48 h after ictus) of 745 aSAH cases treated between January 2003 and June 2016 were reviewed with regard to Subarachnoid Hemorrhage Early Brain Edema Score (SEBES), and Claassen, Barrow Neurological Institute (BNI), Hijdra, original Graeb and Fisher scale scores. The primary endpoints were development of delayed cerebral ischemia (DCI), in-hospital mortality and unfavorable outcome (modified Rankin Scale score >3) at 6 months after subarachnoid hemorrhage. Secondary endpoints included the different complications that can occur during aSAH. Clinically relevant cutoffs were defined using receiver-operating characteristic curves. The radiographic scores with the highest values for area under the curve (AUC) were included in the final multivariate analysis.

RESULTS

The Hijdra sum score had the most accurate predictive value and independent associations with all primary endpoints: DCI (AUC 0.678, adjusted odds ratio [aOR] 2.83; p < 0.0001); in-hospital mortality (AUC 0.704, aOR 2.83; p < 0.0001) and unfavorable outcome (AUC 0.726, aOR 2.91; p < 0.0001). Multivariate analyses confirmed the independent predictive value of the radiographic scales for risk of decompressive craniectomy (SEBES and Fisher score), cerebral vasospasm (SEBES, BNI score and Fisher score) and shunt dependency (Hijdra ventricle score and Fisher score) after aSAH.

CONCLUSIONS

Initial radiographic severity of aSAH was independently associated with occurrence of different complications during aSAH and the final outcome. The Hijdra sum score showed the highest diagnostic accuracy and robust predictive value for early detection of risk of DCI, in-hospital mortality and unfavorable outcome after aSAH.

Racial differences in time to blood pressure control of aneurysmal subarachnoid hemorrhage patients: A single-institution study

BACKGROUND AND PURPOSE

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 patients annually in the United States. Uncontrolled blood pressure is a major risk factor for aneurysmal subarachnoid hemorrhage. Clinical guidelines recommend maintaining blood pressure control until definitive aneurysm securement occurs. It is unknown whether racial differences exist regarding blood pressure control and outcomes (HLOS, discharge disposition) in aneurysmal subarachnoid hemorrhage. Here, we aim to assess whether racial differences exist in 1) presentation, 2) clinical course, and 3) outcomes, including time to blood pressure stabilization, for aSAH patients at a large tertiary care medical center.

METHODS

We conducted a retrospective review of adult aneurysmal subarachnoid hemorrhage cases from 2013 to 2019 at a single large tertiary medical center. Data extracted from the medical record included sex, age, race, insurance status, aneurysm location, aneurysm treatment, initial systolic and diastolic blood pressure, Hunt Hess grade, modified Fisher score, time to blood pressure control (defined as time in minutes from first blood pressure measurement to the first of three consecutive systolic blood pressure measurements under 140mmHg), hospital length of stay, and final discharge disposition.

RESULTS

194 patients met inclusion criteria; 140 (72%) White and 54 (28%) Black. While White patients were more likely than Black patients to be privately insured (62.1% versus 33.3%, p < 0.001), Black patients were more likely than White patients to have Medicaid (55.6% versus 15.0%, p < 0.001). Compared to White patients, Black patients presented with a higher median systolic (165 mmHg versus 148 mmHg, p = 0.004) and diastolic (93 mmHg versus 84 mmHg, p = 0.02) blood pressure. Black patients had a longer median time to blood pressure control than White patients (200 minutes versus 90 minutes, p = 0.001). Black patients had a shorter median hospital length of stay than White patients (15 days versus 18 days, p < 0.031). There was a small but statistically significant difference in modified Fisher score between black and white patients (3.48 versus 3.17, p = 0.04).There were no significant racial differences present in sex, Hunt Hess grade, discharge disposition, complications, or need for further interventions.

CONCLUSION

Black race was associated with higher blood pressure at presentation, longer time to blood pressure control, but shorter hospital length of stay. No racial differences were present in aneurysmal subarachnoid hemorrhage associated complications or interventions.

An update of predictors of cerebral infarction after aneurysmal subarachnoid hemorrhage: systematic review and meta-analysis

INTRODUCTION

Evidence about predictors of poor outcomes such as cerebral infarction (CI) after aneurysmal subarachnoid hemorrhage (aSAH) has not been fully elucidated.

EVIDENCE ACQUISITION

We performed a systematic review and meta-analysis on studies with adults with aSAH considering RCT and non-RCT, prospective, and retrospective cohort studies describing clinical, imaging as well as angiographic studies in patients with aSAH.

EVIDENCE SYNTHESIS

After reviewing the complete text, 11 studies were considered eligible, out of which four were ruled out. Degree of clinical severity was the most predictive factor with a higher degree at the presentation on different severity scales being associated with a statistically significant increasing the risk of suffering a CI following aSAH (OR 2.49 [95% CI 1.38-4.49] P=0.0003). Aneurysm size increased the risk of CI (OR 1.49 [95% CI 1.20-1.85] P=0.0003; I²=4%). In six studies analyzed, it was found that an important factor for the subsequent development of CI is vasospasm (OR 7.62 [2.19, 26.54], P=0.0001).

CONCLUSIONS

The development of vasospasm is a risk factor for CI development after aSAH. In our review, three factors were associated with an increased risk of CI: clinical severity at presentation, vasospasm, and aneurysm size. The major limitation of this meta-analysis is that included studies were conducted retrospectively or were post hoc analyses of a prospective trial.

Genetic variation in NFE2L2 is associated with outcome following aneurysmal subarachnoid haemorrhage

BACKGROUND AND PURPOSE

Nuclear factor erythroid 2-related factor 2 (NRF2; encoded by the NFE2L2 gene) has been implicated in outcome following aneurysmal subarachnoid haemorrhage (aSAH) through its activity as a regulator of inflammation, oxidative injury and blood breakdown product clearance. The aim of this study was to identify whether genetic variation in NFE2L2 is associated with clinical outcome following aSAH.

METHODS

Ten tagging single nucleotide polymorphisms (SNPs) in NFE2L2 were genotyped and tested for association with dichotomized clinical outcome, assessed by the modified Rankin scale, in both a discovery and a validation cohort. In silico functional analysis was performed using a range of bioinformatic tools.

RESULTS

One SNP, rs10183914, was significantly associated with outcome following aSAH in both the discovery (n = 1007) and validation cohorts (n = 466). The risk of poor outcome was estimated to be 1.33-fold (95% confidence interval 1.12-1.58) higher in individuals with the T allele of rs10183914 (p_{meta-analysis}  = 0.001). In silico functional analysis identified rs10183914 as a potentially regulatory variant with effects on transcription factor binding in addition to alternative splicing with the T allele, associated with a significant reduction in the NFE2L2 intron excision ratio (p_sQTL  = 1.3 × 10^-7 ).

CONCLUSIONS

The NFE2L2 SNP, rs10183914, is significantly associated with outcome following aSAH. This is consistent with a clinically relevant pathophysiological role for oxidative and inflammatory brain injury due to blood and its breakdown products in aSAH. Furthermore, our findings support NRF2 as a potential therapeutic target following aSAH and other forms of intracranial haemorrhage.

Predictive factors for pre-intervention rebleeding in aneurysmal subarachnoid haemorrhage: a systematic review and meta-analysis

Rebleeding before intervention is a devastating complication of aneurysmal subarachnoid haemorrhage (aSAH). It often occurs early and is associated with poor outcomes. We present a systematic review and meta-analysis to identify potential predictors of rebleeding in aSAH. A database search identified studies detailing the occurrence of pre-intervention rebleeding in aSAH, and 809 studies were screened. The association between rebleeding and a variety of demographic, clinical, and radiological factors was examined using random effects meta-analyses. Fifty-six studies totalling 33,268 patients were included. Rebleeding occurred in 3,223/33,268 patients (11.1%, 95%CI 9.4-13), with risk decreasing by approximately 0.2% per year since 1981. Systolic blood pressure (SBP) during admission was higher in patients who rebled compared with those who did not (MD 7.4 mmHg, 95%CI 2.2 - 12.7), with increased risk in cohorts with SBP > 160 mmHg (RR 2.12, 95%CI 1.35-3.34), but not SBP > 140 mmHg. WFNS Grades IV-V (RR 2.05, 95%CI 1.13-3.74) and Hunt-Hess grades III-V (RR 2.12, 95%CI 1.38-3.28) were strongly associated with rebleeding. Fisher grades IV (RR 2.24, 95%CI 1.45-3.49) and III-IV (RR 2.05, 95%CI 1.17-3.6) were also associated with an increased risk. Awareness of potential risk factors for rebleeding is important when assessing patients with aSAH to ensure timely management in high-risk cases. Increased SBP during admission, especially > 160 mmHg, poorer clinical grades, and higher radiological grades are associated with an increased risk. These results may also aid in designing future studies assessing interventions aimed at reducing the risk of rebleeding.

A Review of Genetic Polymorphisms and Susceptibilities to Complications after Aneurysmal Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) and vasospasm are two complications of subarachnoid hemorrhages (SAHs) which entail high risks of morbidity and mortality. However, it is unknown why only some patients who suffer SAHs will experience DCI and vasospasm. The purpose of this review is to describe the main genetic single nucleotide polymorphisms (SNPs) that have demonstrated a relationship with these complications. The SNP of the nitric oxide endothelial synthase (eNOS) has been related to the size and rupture of an aneurysm, as well as to DCI, vasospasm, and poor neurological outcome. The SNPs responsible for the asymmetric dimetilarginine and the high-mobility group box 1 have also been associated with DCI. An association between vasospasm and the SNPs of the eNOS, the haptoglobin, and the endothelin-1 receptor has been found. The SNPs of the angiotensin-converting enzyme have been related to DCI and poor neurological outcome. Studies on the SNPs of the Ryanodine Receptor yielded varying results regarding their association with vasospasm.

Spontaneous subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) is the third most common subtype of stroke. Incidence has decreased over past decades, possibly in part related to lifestyle changes such as smoking cessation and management of hypertension. Approximately a quarter of patients with SAH die before hospital admission; overall outcomes are improved in those admitted to hospital, but with elevated risk of long-term neuropsychiatric sequelae such as depression. The disease continues to have a major public health impact as the mean age of onset is in the mid-fifties, leading to many years of reduced quality of life. The clinical presentation varies, but severe, sudden onset of headache is the most common symptom, variably associated with meningismus, transient or prolonged unconsciousness, and focal neurological deficits including cranial nerve palsies and paresis. Diagnosis is made by CT scan of the head possibly followed by lumbar puncture. Aneurysms are commonly the underlying vascular cause of spontaneous SAH and are diagnosed by angiography. Emergent therapeutic interventions are focused on decreasing the risk of rebleeding (ie, preventing hypertension and correcting coagulopathies) and, most crucially, early aneurysm treatment using coil embolisation or clipping. Management of the disease is best delivered in specialised intensive care units and high-volume centres by a multidisciplinary team. Increasingly, early brain injury presenting as global cerebral oedema is recognised as a potential treatment target but, currently, disease management is largely focused on addressing secondary complications such as hydrocephalus, delayed cerebral ischaemia related to microvascular dysfunction and large vessel vasospasm, and medical complications such as stunned myocardium and hospital acquired infections.

Acute hydrocephalus and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage

BACKGROUND

Delayed cerebral infarction (DCIn) following aneurysmal subarachnoid hemorrhage (aSAH) is a major cause of morbi-mortality; yet, the causes for DCIn remain incompletely understood.

OBJECTIVE

We tested the hypothesis that acute hydrocephalus could be related to the occurrence of DCIn, independently of the occurrence and severity of vasospasm.

METHODS

Radiological and clinical data of patients treated at a single large volume academic center for aSAH between 2017 and 2019 were retrospectively analyzed. DCIn was defined as imaging stigma of cerebral infarction visible on 6-week imaging follow-up after aSAH. Hydrocephalus was defined on baseline imaging as a relative bicaudate index above 1. Cerebral vasospasm was defined by reduction of artery diameter in comparison with initial diameter. We used uni- and multivariable models to test the associations between these variables, hydrocephalus and DCIn.

RESULTS

Of 164 included patients, vasospasm occurred in 58 patients (35.4%), and DCIn in 47 (28.7%). Acute hydrocephalus was present in 85 patients (51.8%) on baseline CT. No relation was found between acute hydrocephalus and delayed cerebral infarction in our multivariate analysis (adjusted OR: 1.20 95% CI [0.43-3.37]; p = 0.732). Only vasospasm occurrence was independently associated with DCIn (adjusted OR: 10.97 95% CI [4.60-26.01]).

CONCLUSION

Our study did not show an association between acute hydrocephalus and DCIn after aSAH, after adjustment for the presence and severity of cerebral vasospasm.

A Quantitative Subarachnoid Hemorrhage Grading System, Including Supratentorial and Infratentorial Cisterns, With Multiplanar Computed Tomography Reformations

Background

Subarachnoid hemorrhage (SAH) grading scales typically evaluate a limited number of cisterns on the axial plane. The goal of our study is to apply a simple quantitative yet comprehensive SAH grading scale to all major intracranial cisterns, including the infratentorial cisterns, with multiplanar computed tomography (CT) reformations.

Methodology

We performed a retrospective review of 94 consecutive cases of spontaneous SAH presenting within 72 hours of onset. SAH was categorized into five grades based on the short-axis thickness of SAH in 20 intracranial cisterns measured on the axial, coronal, and sagittal planes. Statistical analysis was performed for inter-rater agreement with kappa statistics, for inter-plane agreement by Spearman correlation statistics, and for inter-rater and inter-plane agreement by Pearson correlation statistics.

Results

The extended kappa coefficient for the three reviewers across all 20 cisterns varied from 0.38 (0.27, 0.50) to 0.59 (0.52, 0.65) on the axial plane. The kappa coefficient for two reviewers varied from 0.46 (0.33, 0.59) to 0.70 (0.60, 0.80) on the coronal plane and from 0.35 (0.20, 0.49) to 0.87 (0.77, 0.96) on the sagittal plane. The average grade of cisterns per case demonstrated mostly excellent correlation between the imaging planes with Spearman correlation statistics (≥0.70). Pairwise concordance correlation coefficient of the total SAH score revealed agreement ranging from 0.81 to 0.90 in all three planes. Pearson correlation statistics of the average total SAH scores revealed excellent correlation among the three planes (≥0.91).

Conclusion

A simple quantitative SAH grading scale can be successfully applied to the supratentorial and infratentorial cisterns in three standard CT imaging planes.

Scoring system to predict hospital outcome after subarachnoid hemorrhage-incorporating systemic response: The CRIG score

OBJECTIVES

Local and systemic proinflammatory and prothrombotic processes after aneurysmal subarachnoid hemorrhage (aSAH) precipitate delayed cerebral ischemia (DCI) and determine clinical outcome. Recent studies using admission and temporal trends of mean platelet volume to platelet count ratio (MPV:PLT) and neutrophil to lymphocyte ratio (NLR) have identified patients developing DCI. We examine if MPV:PLT and NLR along with admission clinical or radiological features can be used to develop a scoring system to predict DCI and in-hospital clinical outcome.

MATERIALS AND METHODS

A 7-year retrospective cohort of aSAH patients admitted to a tertiary care medical center was used to study and identify clinical, radiological and laboratory parameters to predict DCI and clinical outcome (good: discharge to home or rehabilitation facility; poor: all other discharge destinations). Using regression analyses a scoring system (Clinical, Radiological, Inflammatory, dysGlycemia, CRIG) was developed.

RESULTS

Of 271 patients, admission clinical grade (World Federation of Neurological Surgeons' scale), radiological grade (modified Fisher score), NLR and glycated hemoglobin were identified as contributors for CRIG score. CRIG_DCI score threshold of 112 and CRIG_discharge 109, respectively predicted DCI and adverse clinical outcome in score development cohort. The same threshold predicted DCI and adverse clinical outcome with 78.1 and 100% sensitivity, 44.0 and 52.2% specificity, and 63.2 and 61.4% accuracy, respectively in the score validation cohort.

CONCLUSIONS

CRIG is an easily calculable scoring system that incorporates systemic response of aSAH - thus, alluding to its multisystem nature. It can be used at the time of admission to predict DCI and clinical outcome.

Cerebral Microdialysis-Based Interventions Targeting Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI), a complication of subarachnoid hemorrhage (SAH), is linked to cerebral vasospasm and associated with poor long-term outcome. We implemented a structured cerebral microdialysis (CMD) based protocol using the lactate/pyruvate ratio (LPR) as an indicator of the cerebral energy metabolic status in the neurocritical care decision making, using an LPR ≥ 30 as a cutoff suggesting an energy metabolic disturbance. We hypothesized that CMD monitoring could contribute to active, protocol-driven therapeutic interventions that may lead to the improved management of patients with SAH.

METHODS

Between 2018 and 2020, 49 invasively monitored patients with SAH, median Glasgow Coma Scale 11 (range 3-15), and World Federation of Neurosurgical Societies scale 4 (range 1-5) on admission receiving CMD were included. We defined a major CMD event as an LPR ≥ 40 for ≥ 2 h and a minor CMD event as an LPR ≥ 30 for ≥ 2 h.

RESULTS

We analyzed 7,223 CMD samples over a median of 6 days (5-8). Eight patients had no CMD events. In 41 patients, 113 minor events were recorded, and in 23 patients 42 major events were recorded. Our local protocols were adhered to in 40 major (95%) and 98 minor events (87%), with an active intervention in 32 (76%) and 71 (63%), respectively. Normalization of energy metabolic status (defined as four consecutive samples with LPR < 30 for minor and LPR < 40 for major events) was seen after 69% of major and 59% of minor events. The incidence of DCI-related infarcts was 10% (five patients), with only two observed in a CMD-monitored brain region.

CONCLUSIONS

Active interventions were initiated in a majority of LPR events based on CMD monitoring. A low DCI incidence was observed, which may be associated with the active interventions. The potential aid of CMD in the clinical decision-making targeting DCI needs confirmation in additional SAH studies.

Spreading depolarizations in ischaemia after subarachnoid haemorrhage, a diagnostic phase III study

Focal brain damage after aneurysmal subarachnoid haemorrhage predominantly results from intracerebral haemorrhage, and early and delayed cerebral ischaemia. The prospective, observational, multicentre, cohort, diagnostic phase III trial, DISCHARGE-1, primarily investigated whether the peak total spreading depolarization-induced depression duration of a recording day during delayed neuromonitoring (delayed depression duration) indicates delayed ipsilateral infarction. Consecutive patients (n = 205) who required neurosurgery were enrolled in six university hospitals from September 2009 to April 2018. Subdural electrodes for electrocorticography were implanted. Participants were excluded on the basis of exclusion criteria, technical problems in data quality, missing neuroimages or patient withdrawal (n = 25). Evaluators were blinded to other measures. Longitudinal MRI, and CT studies if clinically indicated, revealed that 162/180 patients developed focal brain damage during the first 2 weeks. During 4.5 years of cumulative recording, 6777 spreading depolarizations occurred in 161/180 patients and 238 electrographic seizures in 14/180. Ten patients died early; 90/170 developed delayed infarction ipsilateral to the electrodes. Primary objective was to investigate whether a 60-min delayed depression duration cut-off in a 24-h window predicts delayed infarction with >0.60 sensitivity and >0.80 specificity, and to estimate a new cut-off. The 60-min cut-off was too short. Sensitivity was sufficient [= 0.76 (95% confidence interval: 0.65-0.84), P = 0.0014] but specificity was 0.59 (0.47-0.70), i.e. <0.80 (P < 0.0001). Nevertheless, the area under the receiver operating characteristic (AUROC) curve of delayed depression duration was 0.76 (0.69-0.83, P < 0.0001) for delayed infarction and 0.88 (0.81-0.94, P < 0.0001) for delayed ischaemia (reversible delayed neurological deficit or infarction). In secondary analysis, a new 180-min cut-off indicated delayed infarction with a targeted 0.62 sensitivity and 0.83 specificity. In awake patients, the AUROC curve of delayed depression duration was 0.84 (0.70-0.97, P = 0.001) and the prespecified 60-min cut-off showed 0.71 sensitivity and 0.82 specificity for reversible neurological deficits. In multivariate analysis, delayed depression duration (β = 0.474, P < 0.001), delayed median Glasgow Coma Score (β = -0.201, P = 0.005) and peak transcranial Doppler (β = 0.169, P = 0.016) explained 35% of variance in delayed infarction. Another key finding was that spreading depolarization-variables were included in every multiple regression model of early, delayed and total brain damage, patient outcome and death, strongly suggesting that they are an independent biomarker of progressive brain injury. While the 60-min cut-off of cumulative depression in a 24-h window indicated reversible delayed neurological deficit, only a 180-min cut-off indicated new infarction with >0.60 sensitivity and >0.80 specificity. Although spontaneous resolution of the neurological deficit is still possible, we recommend initiating rescue treatment at the 60-min rather than the 180-min cut-off if progression of injury to infarction is to be prevented.

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

Background

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

Methods

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

Results

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

Conclusion

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

ABO blood group in aneurysmal subarachnoid haemorrhage-a pilot study

PURPOSE

To evaluate the distribution and impact of ABO blood group on the baseline characteristics and clinical outcomes of patients presenting with aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

Retrospective, single-centre study of patients admitted to a neurosurgical department in the UK, with a diagnosis of spontaneous subarachnoid haemorrhage between May 2014 and January 2020. Patients were categorised by ABO blood type and by Rhesus status. Clinical outcomes such as initial bleeding, rebleeding, delayed cerebral ischaemia (DIND) and venous thromboembolism were analysed in relation to the size of their association with ABO blood type. Hospital mortality rate, Glasgow Outcome Score (GOS) - at discharge and 3 months post-ictus, requirement for ventriculoperitoneal shunt insertion, discharge destination and inpatient length of stay were also considered.

RESULTS

Four-hundred twelve adult patients admitted with aSAH were included in our analysis. The distribution of ABO group or Rhesus status in our cohort did not differ significantly from the general population in the UK. Blood group A patients had a significantly increased risk of developing DIND, compared with non-blood group A patients (OR, 1.88 [95% CI: 1.10-3.21]).

CONCLUSIONS

ABO blood type appears to influence aSAH sequelae. Blood group A patients are at highest risk of DIND following aSAH.

Combining Transcranial Doppler and EEG Data to Predict Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

BACKGROUND AND OBJECTIVES

Delayed cerebral ischemia (DCI) is the leading complication of subarachnoid hemorrhage (SAH). Because DCI was traditionally thought to be caused by large vessel vasospasm, transcranial Doppler ultrasounds (TCDs) have been the standard of care. Continuous EEG has emerged as a promising complementary monitoring modality and predicts increased DCI risk. Our objective was to determine whether combining EEG and TCD data improves prediction of DCI after SAH. We hypothesize that integrating these diagnostic modalities improves DCI prediction.

METHODS

We retrospectively assessed patients with moderate to severe SAH (2011-2015; Fisher 3-4 or Hunt-Hess 4-5) who had both prospective TCD and EEG acquisition during hospitalization. Middle cerebral artery (MCA) peak systolic velocities (PSVs) and the presence or absence of epileptiform abnormalities (EAs), defined as seizures, epileptiform discharges, and rhythmic/periodic activity, were recorded daily. Logistic regressions were used to identify significant covariates of EAs and TCD to predict DCI. Group-based trajectory modeling (GBTM) was used to account for changes over time by identifying distinct group trajectories of MCA PSV and EAs associated with DCI risk.

RESULTS

We assessed 107 patients; DCI developed in 56 (51.9%). Univariate predictors of DCI are presence of high-MCA velocity (PSV ≥200 cm/s, sensitivity 27%, specificity 89%) and EAs (sensitivity 66%, specificity 62%) on or before day 3. Two univariate GBTM trajectories of EAs predicted DCI (sensitivity 64%, specificity 62.75%). Logistic regression and GBTM models using both TCD and EEG monitoring performed better. The best logistic regression and GBTM models used both TCD and EEG data, Hunt-Hess score at admission, and aneurysm treatment as predictors of DCI (logistic regression: sensitivity 90%, specificity 70%; GBTM: sensitivity 89%, specificity 67%).

DISCUSSION

EEG and TCD biomarkers combined provide the best prediction of DCI. The conjunction of clinical variables with the timing of EAs and high MCA velocities improved model performance. These results suggest that TCD and cEEG are promising complementary monitoring modalities for DCI prediction. Our model has potential to serve as a decision support tool in SAH management.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that combined TCD and EEG monitoring can identify delayed cerebral ischemia after SAH.

Prediction and Risk Assessment Models for Subarachnoid Hemorrhage: A Systematic Review on Case Studies

Subarachnoid hemorrhage (SAH) is one of the major health issues known to society and has a higher mortality rate. The clinical factors with computed tomography (CT), magnetic resonance image (MRI), and electroencephalography (EEG) data were used to evaluate the performance of the developed method. In this paper, various methods such as statistical analysis, logistic regression, machine learning, and deep learning methods were used in the prediction and detection of SAH which are reviewed. The advantages and limitations of SAH prediction and risk assessment methods are also being reviewed. Most of the existing methods were evaluated on the collected dataset for the SAH prediction. In some researches, deep learning methods were applied, which resulted in higher performance in the prediction process. EEG data were applied in the existing methods for the prediction process, and these methods demonstrated higher performance. However, the existing methods have the limitations of overfitting problems, imbalance data problems, and lower efficiency in feature analysis. The artificial neural network (ANN) and support vector machine (SVM) methods have been applied for the prediction process, and considerably higher performance is achieved by using this method.

Neurologic Outcome Prediction in the Intensive Care Unit

PURPOSE OF REVIEW

The burden of severe and disabling neurologic injury on survivors, families, and society can be profound. Neurologic outcome prediction, or neuroprognostication, is a complex undertaking with many important ramifications. It allows patients with good prognoses to be supported aggressively, survive, and recover; conversely, it avoids inappropriate prolonged and costly care in those with devastating injuries.

RECENT FINDINGS

Striving to maintain a high prediction performance during prognostic assessments encompasses acknowledging the shortcomings of this task and the challenges created by advances in medicine, which constantly shift the natural history of neurologic conditions. Embracing the unknowns of outcome prediction and the boundaries of knowledge surrounding neurologic recovery and plasticity is a necessary step toward refining neuroprognostication practices and improving the accuracy of prognostic impressions. The pillars of modern neuroprognostication include comprehensive characterization of neurologic injury burden (primary and secondary injuries), gauging cerebral resilience and estimated neurologic reserve, and tying it all together with individual values surrounding the acceptable extent of disability and the difficulties of an arduous convalescence journey.

SUMMARY

Comprehensive multimodal frameworks of neuroprognostication using different prognostic tools to portray the burden of neurologic injury coupled with the characterization of individual values and the degree of cerebral reserve and resilience are the cornerstone of modern outcome prediction.

When the Blood Hits Your Brain: The Neurotoxicity of Extravasated Blood

Hemorrhage in the central nervous system (CNS), including intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and aneurysmal subarachnoid hemorrhage (aSAH), remains highly morbid. Trials of medical management for these conditions over recent decades have been largely unsuccessful in improving outcome and reducing mortality. Beyond its role in creating mass effect, the presence of extravasated blood in patients with CNS hemorrhage is generally overlooked. Since trials of surgical intervention to remove CNS hemorrhage have been generally unsuccessful, the potent neurotoxicity of blood is generally viewed as a basic scientific curiosity rather than a clinically meaningful factor. In this review, we evaluate the direct role of blood as a neurotoxin and its subsequent clinical relevance. We first describe the molecular mechanisms of blood neurotoxicity. We then evaluate the clinical literature that directly relates to the evacuation of CNS hemorrhage. We posit that the efficacy of clot removal is a critical factor in outcome following surgical intervention. Future interventions for CNS hemorrhage should be guided by the principle that blood is exquisitely toxic to the brain.

Relationship of the vascular territory affected by delayed cerebral ischemia and the location of the ruptured aneurysm in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

To determine the area most at risk of delayed cerebral ischemia (DCI) in relation to the location of the ruptured aneurysm in patients with aneurysmal subarachnoid hemorrhage (aSAH) and, therefore, help to choose the site for focal multimodal neuromonitoring.

METHODS

We retrospectively analyzed angiographic findings, CCT scans, and patient charts of patients who were admitted with aSAH to our neurosurgical intensive care unit between 2009 and 2017. DCI was defined as infarction on CCT 2-6 weeks after aSAH.

RESULTS

DCI occurred in 17.9% out of 357 included patients. A DCI occurring in the vascular territory of the artery carrying the ruptured aneurysm was found in 81.0% of patients with anterior circulation aneurysms but only in 16.7% with posterior circulation aneurysms (Fisher's exact, p=0.003). The vascular territory most frequently showing a DCI was the ipsilateral MCA territory (86.7%) in ICA aneurysms, the contra- (71.4%) and the ipsilateral (64.3%) ACA territory in ACA aneurysms, the right (93.8%) and the left (81.3%) ACA territory in AcomA aneurysms, and the ipsilateral MCA territory in MCA aneurysms (69.2%) as well as in VA/PICA/SCA aneurysms (100.0%). DCI after the rupture of a BA aneurysm occurred with 33.3% in 6 out of 8 vascular territories, respectively. DCI of multiple vascular territories occurred in 100.0% of BA aneurysms, 87.5% of AcomA aneurysms, 71.4% of ACA aneurysms, 40.0% of ICA aneurysms, 38.5% of MCA aneurysms, and 33.3% of VA/PICA/SCA aneurysms.

DISCUSSION

Few studies exist that could determine the area most at risk of a DCI after an aSAH. Our data could identify the territory most at risk for DCI with a probability of > 60% except for BA aneurysms, which showed DCI in various areas and patients suffering from multiple DCIs. Either the ipsilateral ACA or MCA were affected by the DCI in about 80% of ACA and more than 90% of AcomA, ICA, MCA, and VA/PICA/SCA aneurysms. Therefore, local intraparenchymal neuromonitoring in the ACA/MCA watershed area might detect the vast majority of DCIs for all aneurysm locations, except for BA aneurysms. In ACA and AcomA aneurysms, bilateral DCI of the ACA territory was common, and bilateral probe positioning might be considered for monitoring high-risk patients. Non-focal monitoring methods might be preferably used after BA aneurysm rupture.

Amount of blood during the subacute phase and clot clearance rate as prognostic factors for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) is a poorly predictable complication occurring after aneurysmal subarachnoid hemorrhage (SAH) that can have dramatic functional consequences. Identifying the patients with the highest risk of DCI may help to institute more suitable monitoring and therapy. Early brain injuries and aneurysm-securing procedure complications could be regarded as confounding factors leading to severity misjudgment. After an early resuscitation phase, a subacute assessment may be more relevant to integrate the intrinsic SAH severity. A retrospective analysis was performed upon patients prospectively included in the registry of SAH patients between July 2015 to April 2020. The amount of cisternal and intraventricular blood were assessed semi-quantitatively on acute and subacute CT scans performed after early resuscitation. A clot clearance rate was calculated from their comparison. The primary endpoint was the occurrence of a DCI. A total of 349 patients were included in the study; 80 (22.9%) experienced DCI. In those patients, higher Fisher grades were observed on acute (p = 0.026) and subacute (p = 0.003) CT scans. On the subacute CT scan, patients who experienced DCI had a higher amount of blood, either at the cisternal (median Hijdra sum score: 11 vs 5, p < 0.001) or intraventricular (median Graeb score: 4 vs 2, p < 0.001) level. There was a negative linear relationship between the cisternal clot clearance rate and the risk of DCI. The assessment of the amount of subarachnoid blood and clot clearance following resuscitation after aneurysmal SAH can be useful for the prediction of neurological outcome.

Treatment of Delayed Cerebral Ischemia in Good-Grade Subarachnoid Hemorrhage: Any Role for Invasive Neuromonitoring?

Background

Good-grade aneurysmal subarachnoid hemorrhage (Hunt and Hess 1–2) is generally associated with a favorable prognosis. Nonetheless, patients may still experience secondary deterioration due to delayed cerebral ischemia (DCI), contributing to poor outcome. In those patients, neurological assessment is challenging and invasive neuromonitoring (INM) may help guide DCI treatment.

Methods

An observational analysis of 135 good-grade SAH patients referred to a single tertiary care center between 2010 and 2018 was performed. In total, 54 good-grade SAH patients with secondary deterioration evading further neurological assessment, were prospectively enrolled for this analysis. The cohort was separated into two groups: before and after introduction of INM in 2014 (pre-INM_SecD: n = 28; post-INM_SecD: n = 26). INM included either parenchymal oxygen saturation measurement (p_tiO₂), cerebral microdialysis or both. Episodes of DCI (p_tiO₂ < 10 mmHg or lactate/pyruvate > 40) were treated via induced hypertension or in refractory cases by endovascular means. The primary outcome was defined as the extended Glasgow outcome scale after 12 months. In addition, we recorded the amount of imaging studies performed and the occurrence of silent and overall DCI-related infarction.

Results

Secondary deterioration, impeding neurological assessment, occurred in 54 (40.0%) of all good-grade SAH patients. In those patients, a comparable rate of favorable outcome at 12 months was observed before and after the introduction of INM (pre-INM_SecD 14 (50.0%) vs. post-INM_SecD 16, (61.6%); p = 0.253). A significant increase in good recovery (pre-INM_SecD 6 (50.0%) vs. post-INM_SecD 14, (61.6%); p = 0.014) was observed alongside a reduction in the incidence of silent infarctions (pre-INM_SecD 8 (28.6%) vs. post-INM_SecD 2 (7.7%); p = 0.048) and of overall DCI-related infarction (pre-INM_SecD 12 (42.8%) vs. post-INM_SecD 4 (23.1%); p = 0.027). The number of CT investigations performed during the DCI time frame decreased from 9.8 ± 5.2 scans in the pre-INM_SecD group to 6.1 ± 4.0 (p = 0.003) in the post-INM_SecD group.

Conclusions

A considerable number of patients with good-grade SAH experiences secondary deterioration rendering them neurologically not assessable. In our cohort, the introduction of INM to guide DCI treatment in patients with secondary deterioration increased the rate of good recovery after 12 months. Additionally, a significant reduction of CT scans and infarction load was recorded, which may have an underestimated impact on quality of life and more subtle neuropsychological deficits common after SAH.

Electronic supplementary material

The online version of this article (10.1007/s12028-020-01169-x) contains supplementary material, which is available to authorized users.

Prognostic value of the 2010 consensus definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Delayed cerebral ischemia (DCI) complicates the recovery of approximately 30% of patients with aneurysmal subarachnoid hemorrhage (aSAH). The definition of DCI widely varies, even though a consensus definition has been recommended since 2010. This study aimed to evaluate the prognostic value of the 2010 consensus definition of DCI in a cohort of patients with aSAH.

METHODS

We conducted a single-center, retrospective, observational study that included consecutive adult patients with aSAH who were admitted to the intensive care unit from January 2010 to December 2014. DCI was evaluated 48 h to 14 days after onset of aSAH symptoms using the 2010 consensus criteria and outcome was assessed by the Glasgow Outcome Scale (GOS) at discharge from hospital.

RESULTS

A total of 340 patients were analyzed and the incidence of DCI was 37.1%. The median time from primary hemorrhage to the occurrence of DCI was 97 h. Neurological deterioration was observed in most (89.7%) of the patients who fulfilled the DCI criteria. The occurrence of DCI was strongly associated with an unfavorable outcome (GOS 1-3) at hospital discharge (OR 2.65, 95% CI 1.69-4.22, p < 0.001).

CONCLUSIONS

The incidence of DCI after aSAH is high and its occurrence is strongly associated with an unfavorable neurological outcome. This finding adds to the previous literature, which has shown that DCI appears to be a major contributor affecting the functional ability of survivors of aSAH. To further advance reliable knowledge of DCI, future studies should adhere to the consensus definition of DCI.

The Modified Fisher Scale Lacks Interrater Reliability

BACKGROUND

The modified Fisher scale (mFS) is a critical clinical and research tool for risk stratification of cerebral vasospasm. As such, the mFS is included as a common data element by the National Institute of Neurological Disorders and Stroke SAH Working Group. There are few studies assessing the interrater reliability of the mFS.

METHODS

We distributed a survey to a convenience sample with snowball sampling of practicing neurointensivists and through the research survey portion of the Neurocritical Care Society Web site. The survey consisted of 15 scrollable CT scans of patients with SAH for mFS grading, two questions regarding the definitions of the scale criteria and demographics of the responding physician. Kendall's coefficient of concordance was used to determine the interrater reliability of mFS grading.

RESULTS

Forty-six participants (97.8% neurocritical care fellowship trained, 78% UCNS-certified in neurocritical care, median 5 years (IQR 3-6.3) in practice, treating median of 80 patients (IQR 50-100) with SAH annually from 32 institutions) completed the survey. By mFS criteria, 30% correctly identified that there is no clear measurement of thin versus thick blood, and 42% correctly identified that blood in any ventricle is scored as "intraventricular blood." The overall interrater reliability by Kendall's coefficient of concordance for the mFS was moderate (W = 0.586, p < 0.0005).

CONCLUSIONS

Agreement among raters in grading the mFS is only moderate. Online training tools could be developed to improve mFS reliability and standardize research in SAH.

Hyperoxemia and Cerebral Vasospasm in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Cerebral vasospasm is a major contributor to disability and mortality after aneurysmal subarachnoid hemorrhage. Oxidation of cell-free hemoglobin plays an integral role in neuroinflammation and is a suggested source of tissue injury after aneurysm rupture. This study sought to determine whether patients with subarachnoid hemorrhage and cerebral vasospasm were more likely to have been exposed to early hyperoxemia than those without vasospasm.

METHODS

This single-center retrospective cohort study included adult patients presenting with aneurysmal subarachnoid hemorrhage to Vanderbilt University Medical Center between January 2007 and December 2017. Patients with an ICD-9/10 diagnosis of aneurysmal subarachnoid hemorrhage were initially identified (N = 441) and subsequently excluded if they did not have intracranial imaging, arterial PaO₂ values or died within 96 h post-rupture (N = 96). The final cohort was 345 subjects. The degree of hyperoxemia was defined by the highest PaO₂ measured within 72 h after aneurysmal rupture. The primary outcome was development of cerebral vasospasm, which included asymptomatic vasospasm and delayed cerebral ischemia (DCI). Secondary outcomes were mortality and modified Rankin Scale.

RESULTS

Three hundred and forty five patients met inclusion criteria; 218 patients (63%) developed vasospasm. Of those that developed vasospasm, 85 were diagnosed with delayed cerebral ischemia (DCI, 39%). The average patient age of the cohort was 55 ± 13 years, and 68% were female. Ninety percent presented with Fisher grade 3 or 4 hemorrhage (N = 310), while 42% presented as Hunt-Hess grade 4 or 5 (N = 146). In univariable analysis, patients exposed to higher levels of PaO₂ by quintile of exposure had a higher mortality rate and were more likely to develop vasospasm in a dose-dependent fashion (P = 0.015 and P = 0.019, respectively). There were no statistically significant predictors that differentiated asymptomatic vasospasm from DCI and no significant difference in maximum PaO₂ between these two groups. In multivariable analysis, early hyperoxemia was independently associated with vasospasm (OR = 1.15 per 50 mmHg increase in PaO2 [1.03, 1.28]; P = 0.013), but not mortality (OR = 1.10 [0.97, 1.25]; P = 0.147) following subarachnoid hemorrhage.

CONCLUSIONS

Hyperoxemia within 72 h post-aneurysmal rupture is an independent predictor of cerebral vasospasm, but not mortality in subarachnoid hemorrhage. Hyperoxemia is a variable that can be readily controlled by adjusting the delivered FiO₂ and may represent a modifiable risk factor for vasospasm.

Aneurysmal Subarachnoid Hemorrhage: the Last Decade

Aneurysmal subarachnoid hemorrhage (SAH) affects six to nine people per 100,000 per year, has a 35% mortality, and leaves many with lasting disabilities, often related to cognitive dysfunction. Clinical decision rules and more sensitive computed tomography (CT) have made the diagnosis of SAH easier, but physicians must maintain a high index of suspicion. The management of these patients is based on a limited number of randomized clinical trials (RCTs). Early repair of the ruptured aneurysm by endovascular coiling or neurosurgical clipping is essential, and coiling is superior to clipping in cases amenable to both treatments. Aneurysm repair prevents rebleeding, leaving the most important prognostic factors for outcome early brain injury from the hemorrhage, which is reflected in the neurologic condition of the patient, and delayed cerebral ischemia (DCI). Observational studies suggest outcomes are better when patients are managed in specialized neurologic intensive care units with inter- or multidisciplinary clinical groups. Medical management aims to minimize early brain injury, cerebral edema, hydrocephalus, increased intracranial pressure (ICP), and medical complications. Management then focuses on preventing, detecting, and treating DCI. Nimodipine is the only pharmacologic treatment that is approved for SAH in most countries, as no other intervention has demonstrated efficacy. In fact, much of SAH management is derived from studies in other patient populations. Therefore, further study of complications, including DCI and other medical complications, is needed to optimize outcomes for this fragile patient population.

Nomogram for predicting delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage in the Chinese population

BACKGROUND

Delayed cerebral ischemia is a serious complication of aneurysmal subarachnoid hemorrhage with debilitating and fatal consequences. Lack of well-established risk factors impedes early identification of high-risk patients with delayed cerebral ischemia. A nomogram provides personalized, evidence-based, and accurate risk estimation. To offset the lack of a predictive tool, we developed a nomogram to predict delayed cerebral ischemia before performing surgical interventions for aneurysmal subarachnoid hemorrhage to aid surgical decision-making.

METHODS

We retrospectively collected data from 887 consecutive eligible Chinese patients who underwent surgical clipping or endovascular coiling for aneurysmal subarachnoid hemorrhage. Patients who previously underwent surgery formed the training cohort (n = 621) for nomogram development; those who underwent surgery later formed the validation cohort (n = 266) to confirm the performance of the model. A multivariate logistic regression analysis identified the independent risk factors associated with delayed cerebral ischemia, which were then incorporated into the nomogram.

RESULTS

Delayed cerebral ischemia was identified in 158/621 patients (25.4%) in the training cohort and in 66/266 patients (24.8%) in the validation cohort. Preoperative factors associated with delayed cerebral ischemia were age > 65 years, modified Fisher grade of 3-4, ruptured aneurysm in the anterior circulation, Hunt-Hess grade of 4-5, high blood pressure on admission, and plasma homocysteine level ≥ 10 μmol/L. Incorporating these six factors in the nomogram achieved efficient concordance indices of 0.73 (95% confidence interval, 0.68-0.77) and 0.65 (95% confidence interval, 0.57-0.72) in predicting delayed cerebral ischemia in the training and validation cohorts, respectively.

CONCLUSIONS

Our model can help determine an individual's risk of developing delayed cerebral ischemia in the Chinese population, and thereby, facilitate reasonable treatment-related decision-making.

Appropriate Blood Pressure in Cerebral Aneurysm Clipping for Prevention of Delayed Ischemic Neurologic Deficits

Background

Delayed ischemic neurologic deficit (DNID) is a problem after cerebral aneurysm clipping. Intraoperative hypotension seems to be indicated as a risk factor, but it remains a controversial issue with varying low-blood pressure levels accepted.

Methods

A retrospective, hospital-based, case-control study was performed with patients who received general anesthesia for cerebral aneurysm clipping. 42 medical record charts were randomly selected and matched 1 : 2 (1 case with DNID : 2 controls without DNID) based on the type of general anesthetic techniques and severity of subarachnoid hemorrhage. The optimal cutoff points of hemodynamic response were calculated by the area under the curve.

Results

Data suggested that the optimal cutoff points for lowest blood pressure for prevention of DNID should be systolic blood pressure (SBP) of 95 mmHg (sensitivity of 78.6%; specificity of 53.6%), diastolic blood pressure (DBP) of 50 mmHg (sensitivity of 71.4%; specificity of 67.9%), and mean arterial pressure (MAP) of 61.7 mmHg (sensitivity of 85.7%; specificity of 35.7%). Furthermore, the optimal cutoff point mean difference baseline blood pressure was recommended as Δ SBP of 36 mmHg (sensitivity of 85.7%; specificity of 60.7%), Δ DBP of 27 mmHg (sensitivity of 92.9%; specificity of 71.4%), and Δ MAP of 32 mmHg (sensitivity of 92.9%; specificity of 85.7%). No significant difference between DNID and non-DNID groups was found for end-tidal carbon dioxide (ETCO₂) and has poor diagnostic value for predicting DNID.

Conclusion

To prevent DNID, we recommend that optimal blood pressure should not be lower than 95 for SBP, 50 for DBP, and 61.7 mmHg for MAP. Additionally, we suggest that Δ SBP, Δ DBP, and Δ MAP should be less than 36, 27, and 32 mmHg, respectively.

Magnesium and Hemorrhage Volume in Patients With Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES

We tested the hypothesis that admission serum magnesium levels are associated with extent of hemorrhage in patients with aneurysmal subarachnoid hemorrhage.

DESIGN

Single-center prospective observational study.

SETTING

Tertiary hospital neurologic ICU.

PATIENTS

Patients with aneurysmal subarachnoid hemorrhage.

INTERVENTIONS

Clinically indicated CT scans and serum laboratory studies.

MEASUREMENTS AND MAIN RESULTS

Demographic, clinical, laboratory, and radiographic data were analyzed. Extent of initial hemorrhage was graded semi-quantitatively on admission CT scans using the modified Fisher scale (grades: 0, no radiographic hemorrhage; 1, thin [< 1 mm in depth] subarachnoid hemorrhage; 2, thin subarachnoid hemorrhage with intraventricular hemorrhage; 3, thick [≥ 1 mm] subarachnoid hemorrhage; 4, thick subarachnoid hemorrhage with intraventricular hemorrhage). We used both ordinal (modified Fisher scale) and dichotomized (thick vs thin subarachnoid hemorrhage) univariate and adjusted logistic regression models to assess associations between serum magnesium and radiographic subarachnoid hemorrhage severity. Data from 354 patients (mean age 55 ± 14 yr, 28.5% male, median admission Glasgow Coma Scale 14 [10-15]) were analyzed. Mean magnesium was lower in patients with thick versus thin subarachnoid hemorrhage (1.92 vs 1.99 mg/dL; p = 0.022). A monotonic trend across categories of modified Fisher scale was found using analysis of variance and Spearman rank correlation (p = 0.015 and p = 0.008, respectively). In adjusted ordinal and binary regression models, lower magnesium levels were associated with higher modified Fisher scale (odds ratio 0.33 per 1 mg/dL increase; 95% CI, 0.14-0.77; p = 0.011) and with thick subarachnoid hemorrhage (odds ratio 0.29 per 1 mg/dL increase; 95% CI, 0.10-0.78; p = 0.015).

CONCLUSIONS

These data support the hypothesis that magnesium influences hemorrhage severity in patients with aneurysmal subarachnoid hemorrhage, potentially through a hemostatic mechanism.