Volumetric quantification of Fisher Grade 3 aneurysmal subarachnoid hemorrhage: a novel method to predict symptomatic vasospasm on admission computerized tomography scans

Machine learning predicts cerebral vasospasm in patients with subarachnoid haemorrhage

BACKGROUND

Cerebral vasospasm (CV) is a feared complication which occurs after 20-40% of subarachnoid haemorrhage (SAH). It is standard practice to admit patients with SAH to intensive care for an extended period of resource-intensive monitoring. We used machine learning to predict CV requiring verapamil (CVRV) in the largest and only multi-center study to date.

METHODS

Patients with SAH admitted to UCLA from 2013 to 2022 and a validation cohort from VUMC from 2018 to 2023 were included. For each patient, 172 unique intensive care unit (ICU) variables were extracted through the primary endpoint, namely first verapamil administration or no verapamil. At each institution, a light gradient boosting machine (LightGBM) was trained using five-fold cross validation to predict the primary endpoint at various hospitalization timepoints.

FINDINGS

A total of 1750 patients were included from UCLA, 125 receiving verapamil. LightGBM achieved an area under the ROC (AUC) of 0.88 > 1 week in advance and ruled out 8% of non-verapamil patients with zero false negatives. Our models predicted "no CVRV" vs "CVRV within three days" vs "CVRV after three days" with AUCs = 0.88, 0.83, and 0.88, respectively. From VUMC, 1654 patients were included, 75 receiving verapamil. VUMC predictions averaged within 0.01 AUC points of UCLA predictions.

INTERPRETATION

We present an accurate and early predictor of CVRV using machine learning with multi-center validation. This represents a significant step towards optimized clinical management and resource allocation in patients with SAH.

FUNDING

Robert E. Freundlich is supported by National Center for Advancing Translational Sciences federal grant UL1TR002243 and National Heart, Lung, and Blood Institute federal grant K23HL148640; these funders did not play any role in this study. The National Institutes of Health supports Vanderbilt University Medical Center which indirectly supported these research efforts. Neither this study nor any other authors personally received financial support for the research presented in this manuscript. No support from pharmaceutical companies was received.

Aneurysmal subarachnoid haemorrhage: Volumetric quantification of the blood distribution pattern to accurately predict the ruptured aneurysm location

BACKGROUND

In spontaneous subarachnoid haemorrhage (SAH) accurate determination of the bleeding source is paramount to guide treatment. Traditionally, the bleeding pattern has been used to predict the aneurysm location. Here, we have tested a software-based tool, which quantifies the volume of intracranial blood and stratifies it according to the regional distribution, to predict the location of the ruptured aneurysm.

METHODS

A consecutive series of SAH patients admitted to a single tertiary centre between 2012-2018, within 72 h of onset, harbouring a single intracranial aneurysm. A semi-automatized method of blood quantification, based on the relative density increase, was applied to initial non-contrast CTs. Five regions were used to define the bleeding patterns and to correlate them with aneurysm location: perimesencephalic, interhemispheric, right/left hemisphere and intraventricular.

RESULTS

68 patients were included for analysis. There was a strong association between the distribution of blood and the aneurysm location (p < 0.001). In particular: ACom and interhemispheric fissure (p < 0.001), MCA and ipsilateral hemisphere (p < 0.001), ICA and ipsilateral hemisphere and perimesencephalic cisterns (p < 0.001), PCom and hemispheric, perimesencephalic and intraventricular (p = 0.019), and PICA and perimesencephalic and intraventricular (p < 0.001). The internal diagnostic value was high (AUROC ≥ 0.900) for these locations.

CONCLUSION

Regional automatised volumetry seems a reliable and objective tool to quantify and describe the distribution of blood within the subarachnoid spaces. This tool accurately predicts the location of the ruptured aneurysm; its use may be prospectively considered in the emergency setting when speed and simplicity are attained.

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.

Red Blood Cells in the Cerebrospinal Fluid Compartment After Subarachnoid Haemorrhage: Significance and Emerging Therapeutic Strategies

Subarachnoid haemorrhage (SAH) is a subtype of stroke that predominantly impacts younger individuals. It is associated with high mortality rates and can cause long-term disabilities. This review examines the contribution of the initial blood load and the dynamics of clot clearance to the pathophysiology of SAH and the risk of adverse outcomes. These outcomes include hydrocephalus and delayed cerebral ischaemia (DCI), with a particular focus on the impact of blood located in the cisternal spaces, as opposed to ventricular blood, in the development of DCI. The literature described underscores the prognostic value of haematoma characteristics, such as volume, density, and anatomical location. The limitations of traditional radiographic grading systems are discussed, compared with the more accurate volumetric quantification techniques for predicting patient prognosis. Further, the significance of red blood cells (RBCs) and their breakdown products in secondary brain injury after SAH is explored. The review presents novel interventions designed to accelerate clot clearance or mitigate the effects of toxic byproducts released from erythrolysis in the cerebrospinal fluid following SAH. In conclusion, this review offers deeper insights into the complex dynamics of SAH and discusses the potential pathways available for advancing its management.

Machine Learning Predicts Cerebral Vasospasm in Subarachnoid Hemorrhage Patients

Background

Cerebral vasospasm (CV) is a feared complication occurring in 20-40% of patients following subarachnoid hemorrhage (SAH) and is known to contribute to delayed cerebral ischemia. It is standard practice to admit SAH patients to intensive care for an extended period of vigilant, resource-intensive, clinical monitoring. We used machine learning to predict CV requiring verapamil (CVRV) in the largest and only multi-center study to date.

Methods

SAH patients admitted to UCLA from 2013-2022 and a validation cohort from VUMC from 2018-2023 were included. For each patient, 172 unique intensive care unit (ICU) variables were extracted through the primary endpoint, namely first verapamil administration or ICU downgrade. At each institution, a light gradient boosting machine (LightGBM) was trained using five- fold cross validation to predict the primary endpoint at various timepoints during hospital admission. Receiver-operator curves (ROC) and precision-recall (PR) curves were generated.

Results

A total of 1,750 patients were included from UCLA, 125 receiving verapamil. LightGBM achieved an area under the ROC (AUC) of 0.88 an average of over one week in advance, and successfully ruled out 8% of non-verapamil patients with zero false negatives. Minimum leukocyte count, maximum platelet count, and maximum intracranial pressure were the variables with highest predictive accuracy. Our models predicted "no CVRV" vs "CVRV within three days" vs "CVRV after three days" with AUCs=0.88, 0.83, and 0.88, respectively. For external validation at VUMC, 1,654 patients were included, 75 receiving verapamil. Predictive models at VUMC performed very similarly to those at UCLA, averaging 0.01 AUC points lower.

Conclusions

We present an accurate (AUC=0.88) and early (>1 week prior) predictor of CVRV using machine learning over two large cohorts of subarachnoid hemorrhage patients at separate institutions. This represents a significant step towards optimized clinical management and improved resource allocation in the intensive care setting of subarachnoid hemorrhage patients.

Subarachnoid Blood Clearance and Aneurysmal Subarachnoid Hemorrhage Outcomes: A Retrospective Review

BACKGROUND

Delayed cerebral ischemia (DCI) continues to be a significant contributor to morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH). Subarachnoid blood and its degradation products have been implicated in DCI, and faster blood clearance has been hypothesized to confer better outcomes. This study evaluates the relationship between blood volume and its clearance on DCI (primary outcome) and location at 30 days (secondary outcome) after aSAH.

METHODS

This is a retrospective review of adult patients presenting with aSAH. Hijdra sum scores (HSS) were assessed independently for each computed tomography (CT) scan of patients with available scans on post-bleed days 0-1 and 2-10. This cohort was used to evaluate the course of subarachnoid blood clearance (group 1). A subset of patients in the first cohort with available CT scans on both post-bleed days 0-1 and post-bleed days 3-4 composed the second cohort (group 2). This group was used to evaluate the association between initial subarachnoid blood (measured via HSS post-bleed days 0-1) and its clearance (measured via percentage reduction [HSS %Reduction] and absolute reduction [HSS-Abs-Reduction] in HSS between days 0-1 and 3-4) on outcomes. Univariable and multivariable logistic regression models were used to identify outcome predictors.

RESULTS

One hundred fifty-six patients were in group 1, and 72 patients were in group 2. In this cohort, HSS %Reduction was associated with decreased risk of DCI in univariate (odds ratio [OR] = 0.700 [0.527-0.923], p = 0.011) and multivariable (OR = 0.700 [0.527-0.923], p = 0.012) analyses. Higher HSS %Reduction was significantly more likely to have better outcomes at 30 days in the multivariable analysis (OR = 0.703 [0.507-0.980], p = 0.036). Initial subarachnoid blood volume was associated with outcome location at 30 days (OR = 1.331 [1.040-1.701], p = 0.023) but not DCI (OR = 0.945 [0.780-1.145], p = 0.567).

CONCLUSIONS

Early blood clearance after aSAH was associated with DCI (univariable and multivariable analyses) and outcome location at 30 days (multivariable analysis). Methods facilitating subarachnoid blood clearance warrant further investigation.

Marked Reduction of Cerebral Vasospasm with Intrathecal Urokinase Infusion Therapy after Endovascular Coil Embolization of the Aneurysmal Subarachnoid Hemorrhage: A Case Series

Delayed cerebral vasospasms after subarachnoid hemorrhage (SAH) are a risk factor for poor prognosis after successful treatment of ruptured intracranial aneurysms. Different strategies to remove clots from the subarachnoid space and prevent vasospasms have different outcomes. Intrathecal urokinase infusion therapy combined with endovascular treatment (EVT) can reduce the incidence of symptomatic vasospasms. To analyze the relationship between symptomatic vasospasms and residual SAHs after urokinase infusion therapy, we retrospectively reviewed the records of 348 consecutive patients managed with EVT and intrathecal urokinase infusion therapy for aneurysmal SAH at our institution between 2010 and 2021. Among them, 163 patients met the study criteria and were classified into two groups according to the presence of residual SAH in the cisterns, Sylvian fissures, and frontal interhemispheric fissure. The incidence of symptomatic vasospasms and the clinical outcomes were assessed. In total, eight (5.0%) patients developed symptomatic vasospasms. Patients with symptomatic vasospasms had a significantly higher incidence of residual SAH in the Sylvian or frontal interhemispheric fissures than those without (P <.0001). No patient with SAHs resolved by urokinase infusion therapy developed symptomatic vasospasms. However, the two groups did not differ significantly in terms of modified Rankin scale scores at discharge. Treatment with intrathecal urokinase infusion after EVT for aneurysmal SAH can substantially reduce the risk of clinically evident vasospasms.

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.

Clinical Outcomes of Primary Subarachnoid Hemorrhage: An Exploratory Cohort Study from Sudan

Background

Although Subarachnoid Hemorrhage (SAH) is an emergency condition, its epidemiology and prognosis remain poorly understood in Africa. We aim to explore the clinical presentations, outcomes, and potential mortality predictors of primary SAH patients within 3 weeks of hospitalization in a tertiary hospital in Sudan.

Methods

We prospectively studied 40 SAH patients over 5 months, with 3 weeks of follow-up for the symptomatology, signs, Glasgow coma scale (GCS), CT scan findings, and outcomes. The fatal outcome group was defined as dying within 3 weeks.

Results

The mean age was 53.5 years (SD, 6.9; range, 41–65), and 62.5% were women. One-third (30.0%) were smokers, 37.5% were hypertensive, two-thirds (62.5%) had elevated blood pressure on admission, 37.5% had >24 hours delayed presentation, and 15% had missed SAH diagnosis. The most common presenting symptoms were headache and neck pain/stiffness, while seizures were reported in 12.5%. Approximately one-quarter of patients (22.5%) had large-sized Computed Tomography scan hemorrhage, and 40.0% had moderate size. In-hospital mortality rate was 40.0% (16/40); and 87.5% of them passed away within the first week. Compared to survivors, fatal outcome patients had significantly higher rates of smoking (50.0%), hypertension (68.8%), elevated presenting blood pressure (93.8%), delayed diagnosis (56.2%), large hemorrhage (56.2%), lower GCS scores at presentation, and cerebral rebleeding ( P < 0.05 for each). The primary causes of death were the direct effect of the primary hemorrhage (43.8%), rebleeding (31.3%), and delayed cerebral infarction (12.5%).

Conclusions

SAH is associated with a high in-hospital mortality rate in this cohort of Sudanese SAH patients due to modifiable factors such as delayed diagnosis, hypertension, and smoking. Strategies toward minimizing these factors are recommended.

Predictive effects of admission white blood cell counts and hounsfield unit values on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Neuroinflammatory response is deemed the primary pathogenesis of delayed cerebral ischemia (DCI) caused by aneurysmal subarachnoid hemorrhage (aSAH). Both white blood cell (WBC) count and Hounsfield Unit (HU) are gradually considered can reflect inflammation in DCI. This study aims to identify the relationship between WBC count and HU value and investigate the effects of both indicators in predicting DCI after aSAH.

METHODS

We enrolled 109 patients with aSAH admitted within 24 h of onset in our study. A multivariate logistic regression analysis was used to evaluate the admission WBC count, HU value, and combined WBC-HU associated with DCI. The receiver operating characteristic curve and area under the curve (AUC) were used to determine thresholds and detect the predictive ability of these predictors. These indicators were also compared with the established inflammation markers.

RESULTS

Thirty-six (33%) patients developed DCI. Both WBC count and HU value were strongly associated with the admission glucose level (ρ = .303, p = .001; ρ = .273, p = .004), World Federation of Neurosurgical Societies grade (ρ = .452, p < .001; ρ = .578; p < .001), Hunt-Hess grade (ρ = .450, p < .001; ρ = .510, p < .001), and modified Fisher scale score (ρ = .357, p < .001; ρ = .330, p < .001). After controlling these public variables, WBC count (ρ = .300, p = .002) positively correlated with HU value. An early elevated WBC (odds ratio [OR] 1.449, 95% confidence interval [CI]: 1.183-1.774, p < .001) count and HU value (OR 1.304, 95%CI: 1.149-1.479, p < .001) could independently predict the occurrence of DCI. However, only these patients with both WBC count and HU value exceeding the cut-off points (OR 36.89, 95%CI: 5.606-242.78, p < .001) were strongly correlated with DCI. Compared with a single WBC count (AUC 0.811, 95%CI: 0.729-0.892, p < .001) or HU value (AUC 0.869, 95%CI: 0.803-0.936, p < .001), the combined WBC-HU (AUC 0.898, 95%CI: 0.839-0.957, p < .001) demonstrated a better ability to predict the occurrence of DCI. Inspiringly, the prediction performance of these indicators outperformed the established inflammatory markers.

CONCLUSION

An early elevated WBC count and HU value could independently predict DCI occurrence between 4 and 30 days after aSAH. Furthermore, WBC count was positively correlated with HU value, and the combined WBC-HU demonstrated a superior prediction ability for DCI development compared with the individual indicator.

Volumetric quantification of aneurysmal subarachnoid hemorrhage independently predicts hydrocephalus and seizures

OBJECTIVE

Hydrocephalus and seizures greatly impact outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH); however, reliable tools to predict these outcomes are lacking. The authors used a volumetric quantitative analysis tool to evaluate the association of total aSAH volume with the outcomes of shunt-dependent hydrocephalus and seizures.

METHODS

Total hemorrhage volume following aneurysm rupture was retrospectively analyzed on presentation CT imaging using a custom semiautomated computer program developed in MATLAB that employs intensity-based k-means clustering to automatically separate blood voxels from other tissues. Volume data were added to a prospectively maintained aSAH database. The association of hemorrhage volume with shunted hydrocephalus and seizures was evaluated through logistic regression analysis and the diagnostic accuracy through analysis of the area under the receiver operating characteristic curve (AUC).

RESULTS

The study population comprised 288 consecutive patients with aSAH. The mean total hemorrhage volume was 74.9 ml. Thirty-eight patients (13.2%) developed seizures. The mean hemorrhage volume in patients who developed seizures was significantly higher than that in patients with no seizures (mean difference 17.3 ml, p = 0.01). In multivariate analysis, larger hemorrhage volume on initial CT scan and hemorrhage volume > 50 ml (OR 2.81, p = 0.047, 95% CI 1.03-7.80) were predictive of seizures. Forty-eight patients (17%) developed shunt-dependent hydrocephalus. The mean hemorrhage volume in patients who developed shunt-dependent hydrocephalus was significantly higher than that in patients who did not (mean difference 17.2 ml, p = 0.006). Larger hemorrhage volume and hemorrhage volume > 50 ml (OR 2.45, p = 0.03, 95% CI 1.08-5.54) were predictive of shunt-dependent hydrocephalus. Hemorrhage volume had adequate discrimination for the development of seizures (AUC 0.635) and shunted hydrocephalus (AUC 0.629).

CONCLUSIONS

Hemorrhage volume is an independent predictor of seizures and shunt-dependent hydrocephalus in patients with aSAH. Further evaluation of aSAH quantitative volumetric analysis may complement existing scales used in clinical practice and assist in patient prognostication and management.

Can admission lipoprotein-associated phospholipase A2 predict the symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage?

Background

Inflammation has been believed to be related to the development of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (aSAH). A potential biomarker for vascular inflammation that is well recognized is the lipoprotein-associated phospholipase A2 (Lp-PLA2). However, whether Lp-PLA2 can predict the occurrence of symptomatic cerebral vasospasm (SCV) in aSAH patients is still unknown. Thus, this study aimed to assess the value of Lp-PLA2 for predicting SCV in patients with aSAH.

Methods

Between March 2017 and April 2018, we evaluated 128 consecutive aSAH patients who were admitted in the First Affiliated Hospital of Fujian Medical University. Their Lp-PLA2 level was obtained within 24 h of the initial bleeding. Factors might be related to SCV were analyzed.

Results

Compared to patients without SCV, those with SCV (9.4%, 12/128) had significantly higher Lp-PLA2 level. Multivariate logistic analysis revealed that worse modified Fisher grade (OR = 10.08, 95% CI = 2.04-49.86, P = 0.005) and higher Lp-PLA2 level (OR = 6.66, 95% CI = 1.33-3.30, P = 0.021) were significantly associated with SCV, even after adjustment for confounders. Based on the best threshold, Lp-PLA2 had a sensitivity of 83.3% and a specificity of 51.7% for predicting SCV, as shown by the receiver operating characteristic curve analysis. In the poor World Federation of Neurosurgical Societies grade patient sub-group, patients with Lp-PLA2 > 200 μg/L had significantly higher SCV rate than that of patients having Lp-PLA2 ≤ 200 μg/L.

Conclusion

The admission Lp-PLA2 level might be a helpful predictor for SCV in aSAH.

Impact of Postoperative Infarcts in Determining Outcome after Clipping of Anterior Communicating Artery Aneurysms

Background

Development of cerebral infarcts following clipping of ruptured intracranial aneurysm is one of the major determinants of functional outcome in patients with subarachnoid hemorrhage (SAH). The aim of this study is to evaluate the factors affecting development of postoperative infarcts, its incidence, pattern, and functional outcome.

Material and Methods

This study includes 118 patients of spontaneous SAH because of ruptured anterior communicating artery aneurysm, who underwent clipping. Relevant points in history, preoperative and intraoperative findings, and postoperative outcome are evaluated.

Results

29 of 118 (24.5%) patients developed postoperative radiological infarcts. Approximately 37.9%, 17.2%, and 3.4% patients developed isolated infarcts, respectively, in anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territory. About 20.7% patients developed infarcts in deep perforator territory. Nine of 29 (31.3%) patients developed multiple-vessel territory infarcts. Patients with poor preoperative neurologic status, prior history of seizure, and history of intraoperative rupture had higher chances of development of infarcts. Development of infarct was irrespective of temporary clipping (TC), duration of clipping, and elective versus rescue clipping. Development of infarcts adversely affected the outcome in significant proportions. Among patients with infarcts, unilateral ACA territory infarcts showed best prognosis, whereas all patients with multiple territory infarcts and PCA territory infarcts died. Age or sex of the patients did not affect the functional outcome. Timing of development of infarcts has no influence on functional recovery.

Conclusion

Development of symptomatic infarct is the sole important predictor of functional outcome. A crowded neurovascular neighborhood and complex variations in local angioarchitecture make anterior communication (ACOM) territory predisposed to operative insults. Elective TC and aggressive management of cerebral vasospasm are recommended to prevent development of infarcts.

Association of Cerebrospinal Fluid Volume with Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Retrospective Volumetric Analysis

BACKGROUND

In aneurysmal subarachnoid hemorrhage (SAH), clot volume has been shown to correlate with the development of radiographic vasospasm (VS), while the role of cerebrospinal fluid (CSF) volume remains largely elusive in the literature. We evaluated CSF volume as a potential surrogate for VS in addition to SAH volume in this retrospective series.

PATIENTS AND METHODS

From a consecutive cohort of aneurysmal SAH (n= 320), cases were included when angiographic evaluation for VS was performed (n= 125). SAH and CSF volumes were volumetrically quantified using an algorithm-assisted segmentation approach on initial computed tomography after ictus. Association with VS was analyzed using regression analysis. Receiver operating characteristic (ROC) curves were used to evaluate predictive accuracy of volumetric measures for VS and to identify cutoffs for risk stratification.

RESULTS

Among 125 included cases, angiography showed VS in 101 (VS+), while no VS was observed in 24 (VS-) cases. In volumetric analysis, mean SAH volume was significantly larger (26.8 ± 21.1 ml vs. 12.6 ± 12.2 ml, p= 0.001), while mean CSF volume was significantly smaller (63.0 ± 31.2 ml vs. 85.7 ± 62.8, p= 0.03) in VS+ compared to VS- cases, respectively. The absence of correlation for SAH and CSF volumes (Pearson R - 0.05, p= 0.58) indicated independence of both measures of the subarachnoid compartment, which was a prerequisite for CSF to act as a new surrogate for VS not related to SAH. Regression analysis confirmed an increased risk of VS with increasing SAH (OR 1.06, 95% CI 1.02-1.11, p= 0.006), while CSF had a protective effect toward VS (OR 0.99, 95% CI 0.98-0.99, p= 0.02). SAH/CSF ratio was also associated with VS (OR 1.03, 95% CI 1.01-1.05, p= 0.015). ROC curves suggested cutoffs at 120 ml CSF and 20 ml SAH for VS stratification. Combination of variables improved stratification accuracy compared to use of SAH alone.

CONCLUSION

This study provides a proof of concept for CSF correlating with angiographic VS after aneurysmal SAH. Quantification of CSF in conjunction with SAH might enhance risk stratification and exhibit advantages over traditional scores. The association of CSF has to be corroborated for delayed cerebral ischemia to further establish CSF as a surrogate parameter.

Hounsfield Unit Value of Interpeduncular Cistern Hematomas Can Predict Symptomatic Vasospasm

Background and Purpose- Symptomatic vasospasm is an important factor that affects the outcomes of aneurysmal subarachnoid hemorrhage. Subarachnoid blood volume can predict symptomatic vasospasm, and we postulated that the blood clot density would also be an important factor involved in such events. The present study aimed to determine the relationship between the incidence of symptomatic vasospasm and the Hounsfield unit (HU) value of the interpeduncular cistern that reflects the density of hematomas. Methods- Data from 323 patients admitted and treated at a single center between 2008 and 2017 within 24 hours of subarachnoid hemorrhage onset were retrospectively analyzed. Initial HU values of the interpeduncular cistern were measured using CT, then correlations with the incidence of symptomatic vasospasm and HU values as well as other variables were assessed. Results- Symptomatic vasospasm developed in 54 (16.7%) of the 323 patients. The incidence of symptomatic vasospasm was low (1.8%, 2/166) for HU <50, but this incidence increased greatly when the HU value exceeded 50 (23.7%, 22/93 for HU >50 to ≤60, and 45.3%, 29/64 for HU >60). The odds ratio for symptomatic vasospasm was 2.0 (95% CI, 1.6-2.4) per 5 HU increase. Symptomatic vasospasm correlated significantly with intraventricular hemorrhage (P=0.05) and with intracerebral hematoma (P=0.046) but even more significantly with the HU value of the interpeduncular cistern (P<0.0001). Conclusions- The HU value of the interpeduncular cistern on initial CT is an accurate and reliable predictor of symptomatic vasospasm.

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

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

Hemorrhagic burden in poor-grade aneurysmal subarachnoid hemorrhage: a volumetric analysis of different bleeding distributions

BACKGROUND

Volumetric assessment of aneurysmal bleeding has been evaluated in few studies and emerged as a promising outcome predictor. There is a lack of studies evaluating its impact in the poor-grade population.

METHODS

Retrospective review of 63 consecutive poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients, defined as grade IV and V according to the World Federation of Neurological Surgeons (WFNS) classifications. Global intracranial bleeding volume was calculated with its subarachnoid, intracerebral (ICH), and intraventricular (IVH) portions by means of analytical software. Univariate and multivariate analyses were performed in order to identify independent predictors of outcome. Good outcome was defined as modified Rankin Scale (mRS) 0-2 and mortality as mRS 6. The cutoff values of bleeding volumes were derived by receiver operating curve (ROC) analysis.

RESULTS

Mean follow-up was of 12.5 (± 1.5) months. Thirty (47.7%) patients achieved good outcome, whereas 19 (30.2) patients out of 63 died. Global intracranial bleeding resulted as an independent predictor of good outcome (cutoff 24 mL). Furthermore, ICH relative percentage of global volume (10% of total) and pure SAH (64% of total) emerged respectively as independent predictors of worsened and improved outcome. Global bleeding volume (cutoff 51 mL) along with global cerebral edema showed to independently predict mortality in the examined poor-grade aSAH population.

CONCLUSIONS

Volumetric assessment of aneurysmal bleeding has the potential for identifying cutoff values that independently predict outcome. Further insights into the relative importance of different bleeding volumes may be implicated in better tailoring the management of this dismal aSAH population.

Association of Quantified Location-Specific Blood Volumes with Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Delayed cerebral ischemia is a severe complication of aneurysmal SAH and is associated with a high case morbidity and fatality. The total blood volume and the presence of intraventricular blood on CT after aneurysmal SAH are associated with delayed cerebral ischemia. Whether quantified location-specific (cisternal, intraventricular, parenchymal, and subdural) blood volumes are associated with delayed cerebral ischemia has been infrequently researched. This study aimed to associate quantified location-specific blood volumes with delayed cerebral ischemia.

MATERIALS AND METHODS

Clinical and radiologic data were collected retrospectively from consecutive patients with aneurysmal SAH with available CT scans within 24 hours after ictus admitted to 2 academic centers between January 2009 and December 2011. Total blood volume was quantified using an automatic hemorrhage-segmentation algorithm. Segmented blood was manually classified as cisternal, intraventricular, intraparenchymal, or subdural. Adjusted ORs with 95% confidence intervals for delayed cerebral ischemia per milliliter of location-specific blood were calculated using multivariable logistic regression analysis.

RESULTS

We included 282 patients. Per milliliter increase in blood volume, the adjusted OR for delayed cerebral ischemia was 1.02 (95% CI, 1.01-1.04) for cisternal, 1.02 (95% CI, 1.00-1.04) for intraventricular, 0.99 (95% CI, 0.97-1.02) for intraparenchymal, and 0.96 (95% CI, 0.86-1.07) for subdural blood.

CONCLUSIONS

Our findings suggest that in patients with aneurysmal subarachnoid hemorrhage, the cisternal blood volume has a stronger relation with delayed cerebral ischemia than the blood volumes at other locations in the brain.

Bilateral Infarction of the Recurrent Arteries of Heubner Following Clipping of an Anterior Communicating Artery Aneurysm

A 50-year-old woman reported to the emergency department with thunderclap headache and vomiting. Non-enhanced brain computed tomography (CT) showed a subarachnoid hemorrhage of Hunt-Hess Grade II and Fisher Grade III. Brain angiography CT and transfemoral cerebral angiography (TFCA) revealed an aneurysm of the anterior communicating artery. A direct neck clipping was performed using the pterional approach. The post-operation CT was uneventful. Six days postoperatively, the patient became lethargic. The mean velocity (cm/s) of the middle cerebral artery peaked at 173 cm/s on the right side and 167 cm/s on the left. A TFCA revealed decreased perfusion in both recurrent arteries of Heubner (RAH), but no occlusion in either. Intra-arterial nimodipine injection was administered. On the 7th postoperative day, CT demonstrated a newly developed low-density lesion in the RAH territory bilaterally. The cause of the infarction was attributed to decreased perfusion caused by cerebral vasospasm. The patient was discharged with no definite neurologic deficit except for mild cognitive disorder.

A Comparison of Computed Tomography-Based Scales with and without Consideration of the Presence or Absence of Intraventricular Hemorrhage in Patients with Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

There has been controversy as to whether intraventricular hemorrhage (IVH) after aneurysmal subarachnoid hemorrhage (SAH) contributes to angiographic cerebral vasospasm (aCV) and delayed cerebral ischemia (DCI). Computed tomography-based SAH scales that did and did not consider IVH were compared in terms of ability to predict aCV, DCI, and outcome.

METHODS

We reviewed 390 patients with ruptured aneurysms who had been treated surgically by day 3 by the same surgeon (T.I.). aCV was graded as 0-4. Outcome at 6 months was classified using the Glasgow Outcome Scale. Inagawa SAH grades and scores, for which only SAH was evaluated, were compared with scales that evaluated both SAH and IVH (Fisher, Claassen, and Frontera grades, and Hijdra score). The area under the receiver operating characteristic curve was calculated to compare severe aCV (grade 3-4), DCI, or poor outcome (Glasgow Outcome Scale score 1-3).

RESULTS

The Inagawa grade showed constant and significant intergrade differences in both aCV and DCI. The Inagawa grade area under the receiver operating characteristic curve values were highest among the scales examined. In the Fisher, Claassen, and Frontera grades, IVH was unlikely to be related to aCV and DCI. There was no significant difference in aCV grade or DCI occurrence between the Inagawa and Hijdra scores. In contrast, the presence of IVH was significantly associated with poor outcome.

CONCLUSIONS

In patients with aneurysmal SAH, IVH is an important factor affecting patient outcome, whereas computed tomography-based SAH scales that do not consider IVH are superior to scales that do consider it for prediction of aCV or DCI.

Application of actuator-driven pulsed water jet in aneurysmal subarachnoid hemorrhage surgery: its effectiveness for dissection around ruptured aneurysmal walls and subarachnoid clot removal

In clipping surgery for aneurysmal subarachnoid hemorrhage (aSAH), critical steps include clot removal and dissection of aneurysms without premature rupture or brain injuries. To pursue this goal, a piezo actuator-driven pulsed water jet (ADPJ) system was introduced in this study. This study included 42 patients, who suffered aSAH and underwent clipping surgery. Eleven patients underwent surgery with the assistance of the ADPJ system (ADPJ group). In the other 31 patients, surgery was performed without the ADPJ system (Control group). The ADPJ system was used for clot removal and aneurysmal dissection. The clinical impact of the ADPJ system was judged by comparing the rate of premature rupture, degree of clot removal, and clinical outcomes. Intraoperatively, a premature rupture was encountered in 18.2 and 25.8% of cases in the ADPJ and control groups, respectively. Although the differences were not statistically significant, intraoperative observation suggested that the ADPJ system was effective in clot removal and dissection of aneurysms in a safe manner. Computed tomography scans indicated the achievement of higher degrees of clot removal, especially when the ADPJ system was used for cases with preoperative clot volumes of more than 25 ml (p = 0.047, Mann-Whitney U test). Clinical outcomes, including incidence of postoperative brain injury or symptomatic vasospasm, were similar in both groups. We described our preliminary surgical results using the ADPJ system for aSAH. Although further study is needed, the ADPJ system was considered a safe and effective tool for clot removal and dissection of aneurysms.

The Hijdra scale has significant prognostic value for the functional outcome of Fisher grade 3 patients with subarachnoid hemorrhage

PURPOSE

Despite its high prevalence among patients with aneurysmal subarachnoid hemorrhage (aSAH) and high risk of delayed cerebral ischemia (DCI), the Fisher grade 3 category remains a poorly studied subgroup. The aim of this cohort study has been to investigate the prognostic value of the Hijdra sum scoring system for the functional outcome in patients with Fisher grade 3 aSAH, in order to improve the risk stratification within this Fisher category.

METHODS

Initial CT scans of 72 prospectively enrolled patients with Fisher grade 3 aSAH were analyzed, and cisternal, ventricular, and total amount of blood were graded according to the Hijdra scale. Additionally, space-occupying subarachnoid blood clots were assessed. Outcome was evaluated after 6 months.

RESULTS

Within the subgroup of Fisher grade 3, aSAH patients with an unfavorable outcome showed a significantly larger cisternal Hijdra sum score (HSS: 21.1 ± 5.2) than patients with a favorable outcome (HSS: 17.6 ± 5.9; p = 0.009). However, both the amount of ventricular blood (p = 0.165) and space-occupying blood clots (p = 0.206) appeared to have no prognostic relevance. After adjusting for the patient's age, gender, tobacco use, clinical status at admission, and presence of intracerebral hemorrhage, the cisternal and total HSS remained the only independent parameters included in multivariate logistic regression models to predict functional outcome (p < 0.01).

CONCLUSION

The cisternal Hijdra score is fairly easy to perform and the present study indicates that it has an additional predictive value for the functional outcome within the Fisher 3 category. We suggest that the Hijdra scale is a practically useful prognostic instrument for the risk evaluation after aSAH and should be applied more often in the clinical setting.

Association of Automatically Quantified Total Blood Volume after Aneurysmal Subarachnoid Hemorrhage with Delayed Cerebral Ischemia

BACKGROUND AND PURPOSE

The total amount of extravasated blood after aneurysmal subarachnoid hemorrhage, assessed with semiquantitative methods such as the modified Fisher and Hijdra scales, is known to be a predictor of delayed cerebral ischemia. However, prediction rates of delayed cerebral ischemia are moderate, which may be caused by the rough and observer-dependent blood volume estimation used in the prediction models. We therefore assessed the association between automatically quantified total blood volume on NCCT and delayed cerebral ischemia.

MATERIALS AND METHODS

We retrospectively studied clinical and radiologic data of consecutive patients with aneurysmal SAH admitted to 2 academic hospitals between January 2009 and December 2011. Adjusted ORs with associated 95% confidence intervals were calculated for the association between automatically quantified total blood volume on NCCT and delayed cerebral ischemia (clinical, radiologic, and both). The calculations were also performed for the presence of an intraparenchymal hematoma and/or an intraventricular hematoma and clinical delayed cerebral ischemia.

RESULTS

We included 333 patients. The adjusted OR of total blood volume for delayed cerebral ischemia (clinical, radiologic, and both) was 1.02 (95% CI, 1.01-1.03) per milliliter of blood. The adjusted OR for the presence of an intraparenchymal hematoma for clinical delayed cerebral ischemia was 0.47 (95% CI, 0.24-0.95) and of the presence of an intraventricular hematoma, 2.66 (95% CI, 1.37-5.17).

CONCLUSIONS

A higher total blood volume measured with our automated quantification method is significantly associated with delayed cerebral ischemia. The results of this study encourage the use of rater-independent quantification methods in future multicenter studies on delayed cerebral ischemia prevention and prediction.

Increased risk of delayed cerebral ischemia in subarachnoid hemorrhage patients with additional intracerebral hematoma

OBJECTIVE Delayed cerebral ischemia (DCI) has a major impact on the outcome of patients suffering from aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to assess the influence of an additional intracerebral hematoma (ICH) on the occurrence of DCI. METHODS The authors conducted a single-center retrospective analysis of cases of SAH involving patients treated between 2006 and 2011. Patients who died or were transferred to another institution within 10 days after SAH without the occurrence of DCI were excluded from the analysis. RESULTS Additional ICH was present in 123 (24.4%) of 504 included patients (66.7% female). ICH was classified as frontal in 72 patients, temporal in 24, and perisylvian in 27. DCI occurred in 183 patients (36.3%). A total of 59 (32.2%) of these 183 patients presented with additional ICH, compared with 64 (19.9%) of the 321 without DCI (p = 0.002). In addition, DCI was detected significantly more frequently in patients with higher World Federation of Neurosurgical Societies (WFNS) grades. The authors compared the original and modified Fisher Scales with respect to the occurrence of DCI. The modified Fisher Scale (mFS) was superior to the original Fisher Scale (oFS) in predicting DCI. Furthermore, they suggest a new classification based on the mFS, which demonstrates the impact of additional ICH on the occurrence of DCI. After the different scales were corrected for age, sex, WFNS score, and aneurysm site, the oFS no longer was predictive for the occurrence of DCI, while the new scale demonstrated a superior capacity for prediction as compared with the mFS. CONCLUSIONS Additional ICH was associated with an increased risk of DCI in this study. Furthermore, adding the presence or absence of ICH to the mFS improved the identification of patients at the highest risk for the development of DCI. Thus, a simple adjustment of the mFS might help to identify patients at high risk for DCI.

Risk Factors for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature

OBJECTIVE

To examine the literature on risk factors for cerebral vasospasm (CV), one of the most serious complications following aneurysmal subarachnoid hemorrhage (SAH), with special reference to the definition of CV.

METHODS

Using standard search engines, including PubMed, the medical literature on risk factors for CV after SAH was reviewed, and the best definition representative of CV was searched.

RESULTS

Severe SAH evident on computed tomography scan was the only consistent risk factor for CV after SAH. Effects of risk factors on CV, including age, clinical grade, rebleeding, intraventricular or intracerebral hemorrhage on computed tomography scan, acute hydrocephalus, aneurysm site and size, leukocytosis, interleukin-6 level, and cardiac abnormalities, appeared to be associated with the severity of SAH rather than each having a direct effect. Cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram were associated with CV without any relationship to SAH severity. With regard to parameters representative of CV, the grade of angiographic vasospasm (i.e., the degree of arterial narrowing evident on angiography) was the most adequate. Nevertheless, few reports on the risk factors associated with angiographic vasospasm grade have been reported to date.

CONCLUSIONS

Severe SAH evident on computed tomography scan appears to be a definite risk factor for CV after SAH, followed by cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram. To understand the pathogenesis of CV, further studies on the relationships between risk factors, especially factors not related to the severity of SAH, and angiographic vasospasm grade are necessary.

Cerebral Vasospasm: A Review

Cerebral vasospasm is a prolonged but reversible narrowing of cerebral arteries beginning days after subarachnoid hemorrhage. Progression to cerebral ischemia is tied mostly to vasospasm severity, and its pathogenesis lies in artery encasement by blood clot, although the complex interactions between hematoma and surrounding structures are not fully understood. The delayed onset of vasospasm provides a potential opportunity for its prevention. It is disappointing that recent randomized, controlled trials did not demonstrate that the endothelin antagonist clazosentan, the cholesterol-lowering agent simvastatin, and the vasodilator magnesium sulfate improve patient outcome. Minimizing ischemia by avoiding inadequate blood volume and pressure, administering the calcium antagonist nimodipine, and intervention with balloon angioplasty, when necessary, constitutes current best management. Over the past two decades, our ability to manage vasospasm has led to a significant decline in patient morbidity and mortality from vasospasm, yet it still remains an important determinant of outcome after aneurysm rupture.

Quantitative analysis of hemorrhage clearance and delayed cerebral ischemia after subarachnoid hemorrhage

OBJECTIVE

Initial hemorrhage burden is an independent predictor for delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, the association between clot clearance and DCI still remains to be elucidated.

METHODS

Quantitative analysis of hemorrhage volume and clot clearance was made in 116 consecutive patients who were scanned within 24 h from onset. Cisternal plus intraventricular hemorrhage volume (CIHV) was calculated as clot volume from the initial scans and scans performed up to 7 days after onset. Clot clearance was calculated as a percentage of residual clot volume compared with the clot volume on the initial scan. Initial clot volume and clot clearance were dichotomized to evaluate the association with DCI.

RESULTS

Included patients were aged 55.5±15.2 years with a female preponderance (65.5%, (76/116)). The group with higher initial clot volume (≥17.2 mL) had higher odds for DCI (OR 4.3, 95% CI 1.3 to 14.0, p=0.015). However, the rate of DCI was not different between high and low clot clearance groups (26.7% vs 31.0%, p=0.66). Clot clearance rate was similar in patients with and without DCI up to day 7 after onset.

CONCLUSIONS

The quantitative clot clearance rate is not an independent predictor for DCI.

Prognostic Value of the Amount of Bleeding After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND:

Quantitative estimation of the hemorrhage volume associated with aneurysm rupture is a new tool of assessing prognosis.

OBJECTIVE:

To determine the prognostic value of the quantitative estimation of the amount of bleeding after aneurysmal subarachnoid hemorrhage, as well the relative importance of this factor related to other prognostic indicators, and to establish a possible cut-off value of volume of bleeding related to poor outcome.

METHODS:

A prospective cohort of 206 patients consecutively admitted with the diagnosis of aneurysmal subarachnoid hemorrhage to Hospital 12 de Octubre were included in the study. Subarachnoid, intraventricular, intracerebral, and total bleeding volumes were calculated using analytic software. For assessing factors related to prognosis, univariate and multivariate analysis (logistic regression) were performed. The relative importance of factors in determining prognosis was established by calculating their proportion of explained variation. Maximum Youden index was calculated to determine the optimal cut point for subarachnoid and total bleeding volume.

RESULTS:

Variables independently related to prognosis were clinical grade at admission, age, and the different bleeding volumes. The proportion of variance explained is higher for subarachnoid bleeding. The optimal cut point related to poor prognosis is a volume of 20 mL both for subarachnoid and total bleeding.

CONCLUSION:

Volumetric measurement of subarachnoid or total bleeding volume are both independent prognostic factors in patients with aneurysmal subarachnoid hemorrhage. A volume of more than 20 mL of blood in the initial noncontrast computed tomography is related to a clear increase in poor outcome risk.

Clot-clearance rate in the sylvian cistern is associated with the severity of cerebral vasospasm after subarachnoid hemorrhage

Rapid clot removal and clearance has been proposed as an effective tool for preventing cerebral vasospasm after subarachnoid hemorrhage (SAH). We examined the relationship between clot-clearance rate and the severity of cerebral vasospasm in 110 consecutive patients with aneurysmal SAH. We measured clot-clearance rates per day in the basal and Sylvian cisterns, and evaluated the presence of symptomatic vasospasm based on changes in clinical symptoms and the appearance of a new low-density area on a computed tomography (CT) scan. The severity of symptomatic cerebral vasospasm was associated with age and the SAH grade on admission; however, we observed no significant difference between these variables in patients with urokinase irrigation or fasudil hydrochloride treatment. The mean clot-clearance rates per day for patients with asymptomatic and permanent delayed ischemic neurological deficit were 41.9 and 41.5 %, respectively, in the basal cistern (P = 0.7358) and 37.7 and 23.9 %, respectively, in the Sylvian cistern (P = 0.0021). The reduced clot-clearance rate in the Sylvian cistern increased the risk of vasospasm-related infarction (P = 0.0093) and markedly reduced unfavorable outcomes (P = 0.0115).

Impaired cerebral autoregulation is associated with vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Cerebral autoregulation may be impaired in the early days after subarachnoid hemorrhage (SAH). The purpose of this study was to examine the relationship between cerebral autoregulation and angiographic vasospasm (aVSP) and radiographic delayed cerebral ischemia (DCI) in patients with SAH.

METHODS

Sixty-eight patients (54±13 years) with a diagnosis of nontraumatic SAH were studied. Dynamic cerebral autoregulation was assessed using transfer function analysis (phase and gain) of the spontaneous blood pressure and blood flow velocity oscillations on days 2 to 4 post-SAH. aVSP was diagnosed using a 4-vessel conventional angiogram. DCI was diagnosed from CT. Decision tree models were used to identify optimal cut-off points for clinical and physiological predictors of aVSP and DCI. Multivariate logistic regression models were used to develop and validate a risk scoring tool for each outcome.

RESULTS

Sixty-two percent of patients developed aVSP, and 19% developed DCI. Patients with aVSP had higher transfer function gain (1.06±0.33 versus 0.89±0.30; P=0.04) and patients with DCI had lower transfer function phase (17.5±39.6 versus 38.3±18.2; P=0.03) compared with those who did not develop either. Multivariable scoring tools using transfer function gain>0.98 and phase<12.5 were strongly predictive of aVSP (92% positive predictive value; 77% negative predictive value; area under the receiver operating characteristic curve, 0.92) and DCI (80% positive predictive value; 91% negative predictive value; area under the curve, 0.94), respectively.

CONCLUSIONS

Dynamic cerebral autoregulation is impaired in the early days after SAH. Including autoregulation as part of the initial clinical and radiographic assessment may enhance our ability to identify patients at a high risk for developing secondary complications after SAH.

Cerebral vasospasm after aneurysmal subarachnoid hemorrhage and traumatic brain injury

OPINION STATEMENT

Cerebral vasospasm (cVSP) consists of the vasoconstriction of large and small intracranial vessels which can lead to cerebral hypoperfusion, and in extreme cases, delayed ischemic deficits with stroke. While most commonly observed after aneurysmal subarachnoid hemorrhage (aSAH), cVSP can also occur after traumatic brain injury (TBI) as we have described in detail in this review. For the past decades, the research attention has focused on cVSP because of its association with delayed cerebral ischemia, which is the largest contributor of morbidity and mortality after aSAH. New discoveries in the cVSP pathophysiology involving multifactorial complex cascades and pathways pose new targets for therapeutic interventions in the prevention and treatment of cVSP. The goal of this review is to demonstrate the commonalities and differences in epidemiology and pathophysiology of both aSAH and TBI-associated cVSP, and highlight the more recently discovered pathways of cVSP. Finally, the latest cVSP surveillance methods and treatment options are illustrated.

Clearing bloody cerebrospinal fluid: clot lysis, neuroendoscopy and lumbar drainage

PURPOSE OF REVIEW

Bloody cerebrospinal fluid (CSF) is a major cause of morbidity and mortality in intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Different treatment strategies aiming at faster clearance of bloody CSF have emerged. The present review focuses on recent developments in the investigation of those treatments.

RECENT FINDINGS

Intraventricular fibrinolysis (IVF) for accelerated IVH-resolution has been clinically tested since the early 1990s. The lately summarized evidence from smaller studies indicates that IVF may result in a benefit in mortality and outcome. Recent investigations have elucidated different aspects of IVF, mainly related to safety. Neuroendoscopy has also emerged as a minimally invasive technique allowing fast removal of IVH. The capability of lumbar drainage to reduce vasospasm after SAH has been tested in a large trial.

SUMMARY

IVF is relatively well tolerated and accelerates clot clearance after IVH. The effect of IVF on clinical outcome and mortality is currently being investigated in a large-scale phase III clinical trial. Neuroendoscopy is feasible for the treatment of IVH, however, larger trials are lacking. Lumbar drainage reduces the incidence of vasospasm after SAH. An ongoing phase III trial has been designed to test its influence on outcome. Lumbar drainage may also reduce shunt-dependency after IVH.

Vasospasm after SAH due to aneurysm rupture of the anterior circle of Willis: value of TCD monitoring

OBJECTIVE

The aim of this study was to verify the presence of angiographic vasospasm in patients with transcranial Doppler (TCD) of high velocities after subarachnoid hemorrhage (SAH).

METHODS

Seven hundred and eighty-six cases admitted within 48 hours after SAH due to the rupture of anterior circulation aneurysm, were prospectively studied with TCD. In cases of TCD velocities higher than 120 cm/s (TCD vasospasm), the patient underwent a control angiography. Hunt-Hess and Fisher's grade on admission CT and location of the aneurysm were related to occurrence of TCD vasospasm. The increase in TCD velocities within 24 hours was calculated and related to the presence of cerebral ischemia on discharge CT, considering three groups of patients: Group A with an increase in velocities higher than 60%, Group B with an increase in velocities between 30 and 60%, and Group C with an increase in velocities lower than 30%.

RESULTS

TCD vasospasm was observed in 216 patients (27%). In 97% of patients with TCD vasospasm on middle cerebral artery (MCA) and in 71% with TCD vasospasm on anterior cerebral artery (ACA), control angiography confirmed the vasospasm, with a significant lower diagnostic TCD predictivity of ACA spasm (chi2=28.204, p=0.000). The overall positive predictive value of TCD was 89%. There was no significant correlation of TCD vasospasm with clinical status on admission and location of the aneurysm, but a significant correlation between occurrence of TCD vasospasm and Fisher's grade (chi2=15.470, p=0.002) and between the increase rate in TCD velocities and cerebral ischemia (chi2=56.564, p=0.000).

CONCLUSION

Our study shows a good correlation between TCD and angiography to detect vasospasm on MCA, but the correlation is low for ACA. TCD alone cannot discriminate different hemodynamic pathways after SAH.

Usefulness of three-dimensional computed tomography to quantify the subarachnoid hemorrhage volume: prediction of symptomatic vasospasm

We quantified the subarachnoid hemorrhage (SAH) volume in 64 patients on three-dimensional computed tomography (3D-CT) scans and studied the correlation between the SAH volume and the occurrence of symptomatic vasospasm (SVS). We studied 64 patients with SAH onset (day 0) and on days 1, 4, 7, and 14. We compared the hematoma volume by 3D-CT with 2D-CT on day 0 and examined the correlation between the hematoma volume and the occurrence of SVS. The hematoma volume, including the volume of normal structures, was automatically calculated (V1). The volume of normal structures manifesting identical CT numbers was previously calculated in patients without intracranial lesions (V2). The total hematoma volume was defined as V1 minus mean value of V2 (= 12 ml). The mean hematoma volume by 3D-CT was 48 ± 12 ml and by 2D-CT was 31 ± 45 ml (mean ± SD, n = 64). The hematoma volume was significantly larger by 3D-CT than by 2D-CT (p < 0.05). At all time points, the hematoma volumes were significantly larger in patients with than without SVS. We developed a new method for the quantitative determination of the SAH volume by 3D-CT. This method may allow us to quantify the volume of SAH in clinical studies of cerebral vasospasm.

Comparison of lumbar drainage and external ventricular drainage for clearance of subarachnoid clots after Guglielmi detachable coil embolization for aneurysmal subarachnoid hemorrhage

OBJECTIVE

Subarachnoid clots play an important role in development of delayed vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to compare clearance of subarachnoid clots using external ventricular drainage (EVD) or lumbar drainage (LD) after Guglielmi detachable coil (GDC) embolization for aneurysmal SAH.

METHODS

The subjects were 51 treated with GDC coil embolization for aneurysmal Fisher group 3 SAH within 72 h of ictus. Software-based volumetric quantification of the subarachnoid clots was performed on CT scans and the hemoglobin (Hb) level was measured in CSF drained from each catheter.

RESULTS

Clearance of subarachnoid clots was more rapid in patients treated with LD (n=34) compared to those treated with EVD (n=17). The Hb level in CSF was significantly higher in the LD group on Days 4-5 after onset of SAH (P<0.05), but was higher in the EVD group on Days 8-9. The incidence of symptomatic vasospasm did not differ between the two groups. The rate of occurrence of a new low density area on CT scans was higher in patients treated with EVD, but not significantly higher than the rate in the LD group.

CONCLUSION

GDC embolization followed by lumbar drainage accelerates the reduction of subarachnoid clots, but EVD may contribute to stasis of hemorrhage within subarachnoid spaces.

The relationship between subarachnoid hemorrhage volume and development of cerebral vasospasm

Objective

The objective of this study is to verify the relationship between subarachnoid hemorrhage (SAH) volume (not Fisher grade) and development of cerebral vasospasm prospectively.

Methods

Patients who visited our hospital with a diffuse or localized thick subarachnoid blood clot seen on computed tomography (CT), taken within 48 hours after SAH and the aneurysm was confirmed by CT Angiogram (CTA) from March 2010 to July 2011 were enrolled in this study. CTA was checked at least twice after admission. Angiographic vasospasm (AVS) on CTA was defined as irregularity or narrowing of intracranial vessels on follow up CTA compared with initial CTA. Total intracranial hemorrhage (ICH) volume (subdural, SAH, intracerebral and intraventricular) was calculated and SAH volume (all supratentorial and infratentorial cisterns) was also calculated using the MIPAV software package.

Results

A total of 55 patients were included in our study. Thirty six patients did not show AVS on CTA or clinical deterioration (non vasospasm group: NVS). AVS without ischemic neurologic symptoms was observed in four patients and development of symptomatic vasospasm (SVS), defined as AVS with ischemic symptoms, was observed in 15 patients. SAH volume in SVS patients was statistically larger than that in NVS patients (p < 0.05). Total ICH volume in SVS patients was larger than that in NVS patients. However, the difference was not statistically significant.

Conclusion

Results of this study indicate an association of development of vasospasm with the SAH volume, not intracranial hemorrhage.

Volumetric analysis of subarachnoid hemorrhage: assessment of the reliability of two computerized methods and their comparison with other radiographic scales

OBJECT

There were two main purposes to this study: first, to assess the feasibility and reliability of 2 quantitative methods to assess bleeding volume in patients who suffered spontaneous subarachnoid hemorrhage (SAH), and second, to compare these methods to other qualitative and semiquantitative scales in terms of reliability and accuracy in predicting delayed cerebral ischemia (DCI) and outcome.

METHODS

A prospective series of 150 patients consecutively admitted to the Hospital 12 de Octubre over a 4-year period were included in the study. All of these patients had a diagnosis of SAH, and diagnostic CT was able to be performed in the first 24 hours after the onset of the symptoms. All CT scans were evaluated by 2 independent observers in a blinded fashion, using 2 different quantitative methods to estimate the aneurysmal bleeding volume: region of interest (ROI) volume and the Cavalieri method. The images were also graded using the Fisher scale, modified Fisher scale, Claasen scale, and the semiquantitative Hijdra scale. Weighted κ coefficients were calculated for assessing the interobserver reliability of qualitative scales and the Hijdra scores. For assessing the intermethod and interrater reliability of volumetric measurements, intraclass correlation coefficients (ICCs) were used as well as the methodology proposed by Bland and Altman. Finally, weighted κ coefficients were calculated for the different quartiles of the volumetric measurements to make comparison with qualitative scales easier. Patients surviving more than 48 hours were included in the analysis of DCI predisposing factors and analyzed using the chi-square or the Mann-Whitney U-tests. Logistic regression analysis was used for predicting DCI and outcome in the different quartiles of bleeding volume to obtain adjusted ORs. The diagnostic accuracy of each scale was obtained by calculating the area under the receiver operating characteristic curve (AUC).

RESULTS

Qualitative scores showed a moderate interobserver reproducibility (weighted κ indexes were always < 0.65), whereas the semiquantitative and quantitative scores had a very strong interobserver reproducibility. Reliability was very high for all quantitative measures as expressed by the ICCs for intermethod and interobserver agreement. Poor outcome and DCI occurred in 49% and 31% of patients, respectively. Larger bleeding volumes were related to a poorer outcome and a higher risk of developing DCI, and the proportion of patients suffering DCI or a poor outcome increased with each quartile, maintaining this relationship after adjusting for the main clinical factors related to outcome. Quantitative analysis of total bleeding volume achieved the highest AUC, and had a greater discriminative ability than the qualitative scales for predicting the development of DCI and outcome.

CONCLUSIONS

The use of quantitative measures may reduce interobserver variability in comparison with categorical scales. These measures are feasible using dedicated software and show a better prognostic capability in relation to outcome and DCI than conventional categorical scales.

In vitro study of cerebrospinal fluid dynamics in a shaken basal cistern after experimental subarachnoid hemorrhage

Background

Cerebral arterial vasospasm leads to delayed cerebral ischemia and constitutes the major delayed complication following aneurysmal subarachnoid hemorrhage. Cerebral vasospasm can be reduced by increased blood clearance from the subarachnoid space. Clinical pilot studies allow the hypothesis that the clearance of subarachnoid blood is facilitated by means of head shaking. A major obstacle for meaningful clinical studies is the lack of data on appropriate parameters of head shaking. Our in vitro study aims to provide these essential parameters.

Methodology/Principal Findings

A model of the basal cerebral cistern was derived from human magnetic resonance imaging data. Subarachnoid hemorrhage was simulated by addition of dyed experimental blood to transparent experimental cerebrospinal fluid (CSF) filling the model of the basal cerebral cistern. Effects of various head positions and head motion settings (shaking angle amplitudes and shaking frequencies) on blood clearance were investigated using the quantitative dye washout method. Blood washout can be divided into two phases: Blood/CSF mixing and clearance. The major effect of shaking consists in better mixing of blood and CSF thereby increasing clearance rate. Without shaking, blood/CSF mixing and blood clearance in the basal cerebral cistern are hampered by differences in density and viscosity of blood and CSF. Blood clearance increases with decreased shaking frequency and with increased shaking angle amplitude. Head shaking facilitates clearance by varying the direction of gravitational force.

Conclusions/Significance

From this in vitro study can be inferred that patient or head shaking with large shaking angles at low frequency is a promising therapeutic strategy to increase blood clearance from the subarachnoid space.

Fate of clots in patients with subarachnoid hemorrhage after different surgical treatment modality: a comparison between surgical clipping and Guglielmi detachable coil embolization

BACKGROUND

Subarachnoid clot is important in the development of delayed vasospasm after subarachnoid hemorrhage (SAH).

OBJECTIVE

To compare the clearance of subarachnoid clot and the incidence of symptomatic vasospasm in surgical clipping and embolization with Guglielmi detachable coils for aneurysmal SAH.

METHODS

The subjects were 115 patients with Fisher group 3 aneurysmal SAH on computed tomography scan at admission whose aneurysm was treated by surgical clipping (clip group; n = 86) or Guglielmi detachable coil embolization (coil group; n = 29) within 72 hours of ictus. Software-based volumetric quantification of the subarachnoid clot was performed, and the amount of hemoglobin in drained cerebrospinal fluid was measured.

RESULTS

Clearance of the subarachnoid clot on the computed tomography scan was rapid in the clip group until the day after the operation but slow in the coil group (58.9% removed vs 27.8% removed; P = .008). However, postoperative clearance of the clot occurred more rapidly in the coil group. Reduction of the clot until days 3 through 5 did not differ significantly between the 2 groups (72.9% removed vs 75.2% removed). The amount of hemoglobin in the clip group was > 0.8 g/d until day 3 and then gradually decreased (n = 15), but hemoglobin in the coil group remained at > 0.8 g/d until day 5 (n = 17). The incidence of symptomatic vasospasm did not differ between the groups.

CONCLUSION

Subarachnoid clot can be removed directly during surgical clipping, which is not possible with endovascular treatment. However, the percentage reduction of the clot on days 3 through 5 did not differ between the 2 groups.

Endovascular treatment of severe vasospasm in nonaneurysmal perimesencephalic subarachnoid hemorrhage

BACKGROUND

Nonaneurysmal perimesencephalic subarachnoid hemorrhage (SAH) has usually a benign prognosis and uneventful course; however, recent reports suggest that these patients may develop severe symptomatic vasospasm.

METHODS

Description of the clinical course of one patient with nonaneurysmal perimesencephalic SAH who required intraarterial infusion of calcium antagonists and transluminal balloon angioplasty for treatment of symptomatic vasospasm. The perimesencephalic clot burden was quantified to determine if there is a relationship with the development of symptomatic vasospasm.

RESULTS

Despite maximized clinical management, the patient described in this report developed vasospasm and delayed cerebral ischemia (DCI), requiring multiple endovascular interventions. The volumetric quantification of subarachnoid blood was 15.4 ml, and was mostly localized in the cisternal space.

CONCLUSIONS

Nonaneurysmal perimesencephalic SAH may have a "malignant" course requiring close neurocritical care monitoring and multiple clinical and endovascular interventions. Moreover, large cisternal hemorrhage was correlated with the development of DCI in this patient with non-aneurysmal SAH.

Perivascular and perineural extension of formed and soluble blood elements in an intracerebral hemorrhage rat model

The perivascular and perineural extension of hematoma has recently been observed in the brain after intracerebral hemorrhage (ICH), which is formed by the leakage of hematoma via the Virchow-Robin spaces (VRS) and the spaces around the nerve fibers (perineurium). The present study investigated the perivascular and perineural extension of a hematoma by studying the distribution of the formed and soluble blood elements labeled with different fluorescein dyes at different times after ICH in a rat model. The ICH rat model was prepared using a modified double injection method. Autologous blood, which contained fluorescein isothiocyanate (FITC)-labeled RBCs or carboxytetramethylrhodamine (TAMRA)-labeled BSA, was injected into the center of the left caudate nucleus. Brain sections were prepared and observed by overlaying fluorescence and hematoxylin and eosin stained images. The formed blood elements extended mainly into the VRS and perineurium in the perihematomal tissue and ipsilateral brain regions near the hematoma. The soluble blood elements extended more extensively to almost all regions of the brain, including some remote brain areas, such as the contralateral cerebral hemisphere and brainstem. Moreover, the fluorescein dyes were observed in lymph sinuses in the bilateral deep cervical lymph nodes as early as 1 hour after ICH. Lymphostasis, which peaked three days after ICH, was observed in the brain tissues around hematoma. The current findings suggest that the perivascular and perineural extension of hematomas widespread distributes in the central nervous system, and is involved in a series of pathologic processes in ICH, such as the remote effects of a hematoma and lymphatic encephalopathy.

Subarachnoid hemorrhage: the first 24 hours. A surgeon's perspective

BACKGROUND

The first 24 h in the management of aneurysmal subarachnoid hemorrhage (SAH) represent a critical time period for medical intervention.

METHODS

We review the current literature and discuss our current clinical practices related to management of acute SAH.

RESULTS

A brief objective review of the current evidence along with a subjective overview of the authors practices in the management of aneurysmal subarachnoid hemorrhage in the first 24 h is outlined.

CONCLUSIONS

The first 24 h following aneurysmal subarachnoid hemorrhage is a critical time period in which medical and interventional management paradigms continue to evolve.