Early vasospasm on admission angiography in patients with aneurysmal subarachnoid hemorrhage is a predictor for in-hospital complications and poor outcome

Elevated cortical blood flow insufficiency volume as a predictor of adverse outcomes in aneurysmal subarachnoid hemorrhage: a large prospective quantitative computed tomography perfusion study

PURPOSE

Early hypoperfusion changes exist in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to investigate a readily obtainable quantitative computed tomography perfusion (CTP) parameter that could assist in quickly identifying patients at risk of delayed cerebral ischemia (DCI) and poor 90-day functional outcomes on admission.

METHODS

We prospectively collected data between 2021.04 and 2022.12. Preoperative CTP data were post-processed using RAPID software. The cortical blood flow insufficiency (CBFI) was defined as Time-to-maximum > 4.0 s. Patients were categorized into four groups according to CBFI volume distribution. To minimize differences among the groups, we employed stabilized inverse probability of treatment weighting (sIPTW). The primary outcome was DCI and poor 90-day functional outcomes (modified Rankin Scale, 3-6) was the secondary outcome. Multivariable Cox or Logistic analysis were performed to estimate the association between CBFI volume and the study outcomes, both before and after sIPTW.

RESULTS

At baseline, the mean (SD) age of the 493 participants was 55.0 (11.8) years, and 299 (60.6%) were female. One hundred and seven participants with DCI and eighty-six participants with poor 90-day functional outcomes were identified. After sIPTW, CBFI volume demonstrated a significant association with DCI (Cox regression: Group 4 versus Group 1, HR 3.69, 95% CI 1.84-7.01) and poor 90-day functional outcomes (Logistic regression: Group 4 versus Group 1, OR 4.61, 95% CI 2.01-12.50).

CONCLUSION

In this study, an elevated preoperative CBFI volume was associated with adverse outcomes in aSAH patients. More well-designed studies are needed to confirm this association.

Clinical Impact and Predictors of Aneurysmal Rebleeding in Poor-Grade Subarachnoid Hemorrhage: Results From the National POGASH Registry

BACKGROUND

Scarce data are available regarding rebleeding predictors in poor-grade aneurysmal subarachnoid hemorrhage (aSAH).

OBJECTIVES

To investigate predictors and clinical impact of rebleeding in a national multicentric poor-grade aSAH.

METHODS

Retrospective analysis of prospectively collected data from the multicentric Poor Grade Aneurysmal Subarachnoid Hemorrhage Study Group (POGASH) registry of consecutive patients treated from January 1, 2015, to June 30th, 2021. Grading was defined as pretreatment World Federation of Neurological Surgeons grading scale IV-V. Ultra-early vasospasm (UEV) was defined as luminal narrowing of intracranial arteries not due to intrinsic disease. Rebleeding was defined as clinical deterioration with evidence of increased hemorrhage on subsequent computed tomography scans, fresh blood from the external ventricular drain, or deterioration before neuroradiological evaluation. Outcome was assessed by the modified Rankin Scale.

RESULTS

Among 443 consecutive World Federation of Neurological Surgeons grades IV-V patients with aSAH treated within a median of 5 (IQR 4-9) hours since onset, rebleeding occurred in 78 (17.6%). UEV (adjusted odds ratio [OR] 6.8, 95% CI 3.2-14.4; P < .001) and presence of dissecting aneurysm (adjusted OR 3.5, 95% CI 1.3-9.3; P = .011) independently predicted rebleeding while history of hypertension (adjusted OR 0.4, 95% CI 0.2-0.8; P = .011) independently reduced its chances. 143 (32.3) patients died during hospitalization. Rebleeding emerged, among others, as an independent predictor of intrahospital mortality (adjusted OR 2.2, 95% CI 1.2-4.1; P = .009).

CONCLUSION

UEV and presence of dissecting aneurysms are the strongest predictors of aneurysmal rebleeding. Their presence should be carefully evaluated in the acute management of poor-grade aSAH.

Treatment of aneurysmal subarachnoid hemorrhage in subacute phase; retrospective comparison of treatment in sub- and hyper-acute phases

OBJECTIVE

As soon as possible treatment initiation for aneurysmal subarachnoid hemorrhage (aSAH) is recommended. However, some patients require treatment in "subacute" phase of aSAH, defined in this study as "more than one day after the onset". To establish an optimal treatment strategy for these patients, we retrospectively analyzed the clinical experience of treating ruptured aneurysm with either clipping or coiling in subacute phase.

METHODS

Patients treated for aSAH between 2015 and 2021were analyzed. Patients were divided into the hyperacute phase (within 24 h) and subacute phase (later than 24 h) groups. The subacute group was analyzed to determine whether the selected procedure and its timing affected postoperative course and clinical outcomes. In addition, we conducted a multivariate logistic regression analysis to determine the independent factors that affect clinical outcomes.

RESULTS

Of 215 patients, 31 were treated in the subacute phase. While cerebral vasospasm at initial imaging was more frequently observed in subacute group, there was no difference in incidence of postoperative vasospasms. Patients in subacute group seemed to have better clinical outcomes due to the milder severity at the time of treatment initiation. Risk of angiographic vasospasm seemed to be higher in patients treated with clipping than coiling, while no difference was seen in clinical outcomes. Multivariate logistic regression analysis showed that the timing and selected treatment did not significantly affect the clinical outcome or the occurrence of delayed vasospasm.

CONCLUSIONS

Treatment of aSAH in the subacute phase may also result in favorable clinical outcomes, similar to patients treated in the hyperacute phase with mild presentation. However, further investigations are required to establish the optimal treatment strategies for such patients.

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.

In-hospital complication-related risk factors for discharge and 90-day outcomes in patients with aneurysmal subarachnoid hemorrhage after surgical clipping and endovascular coiling: a propensity score-matched analysis

OBJECTIVE

More than 10 years have passed since the two best-known clinical trials of ruptured aneurysms (International Subarachnoid Aneurysm Trial [ISAT] and Barrow Ruptured Aneurysm Trial [BRAT]) indicated that endovascular coiling (EC) was superior to surgical clipping (SC). However, in recent years, the development of surgical techniques has greatly improved; thus, it is necessary to reanalyze the impact of the differences in treatment modalities on the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

The authors retrospectively reviewed all aSAH patients admitted to their institution between January 2015 and December 2020. The functional outcomes at discharge and 90 days after discharge were assessed using the modified Rankin Scale (mRS). In-hospital complications, hospital charges, and risk factors derived from multivariate logistic regression were analyzed in the SC and EC groups after 1:1 propensity score matching (PSM). The area under the receiver operating characteristic curve was used to calculate each independent predictor's prediction ability between treatment groups.

RESULTS

A total of 844 aSAH patients were included. After PSM to control for sex, aneurysm location, Hunt and Hess grade, World Federation of Neurosurgical Societies (WFNS) grade, modified Fisher Scale grade, and current smoking and alcohol abuse status, 329 patients who underwent SC were compared with 329 patients who underwent EC. Patients who underwent SC had higher incidences of unfavorable discharge and 90-day outcomes (46.5% vs 33.1%, p < 0.001; and 19.6% vs 13.8%, p = 0.046, respectively), delayed cerebral ischemia (DCI) (31.3% vs 20.1%, p = 0.001), intracranial infection (20.1% vs 1.2%, p < 0.001), anemia (42.2% vs 17.6%, p < 0.001), hypoproteinemia (46.2% vs 21.6%, p < 0.001), and pneumonia (33.4% vs 24.9%, p = 0.016); but a lower incidence of urinary tract infection (1.2% vs 5.2%, p = 0.004) and lower median hospital charges ($12,285 [IQR $10,399-$15,569] vs $23,656 [IQR $18,816-$30,025], p < 0.001). A positive correlation between the number of in-hospital complications and total hospital charges was indicated in the SC (r = 0.498, p < 0.001) and EC (r = 0.411, p < 0.001) groups. The occurrence of pneumonia and DCI, WFNS grade IV or V, and age were common independent risk factors for unfavorable outcomes at discharge and 90 days after discharge in both treatment modalities.

CONCLUSIONS

EC shows advantages in discharge and 90-day outcomes, in-hospital complications, and the number of risk factors but increases the economic cost on patients during their hospital stay. Severe in-hospital complications such as pneumonia and DCI may have a long-lasting impact on the prognosis of patients.

Risk of Re-Rupture, Vasospasm, or Re-Stroke after Clipping or Coiling of Ruptured Intracranial Aneurysms: Long-Term Follow-Up with a Propensity Score-Matched, Population-Based Cohort Study

Scarce evidence is available in Asia for estimating the long-term risk and prognostic factors of major complications such as re-rupture, vasospasm, or re-stroke for patients with aneurysmal subarachnoid hemorrhage (SAH) undergoing endovascular coil embolization or surgical clipping. This is the first head-to-head propensity score-matched study in an Asian population to demonstrate that endovascular coil embolization for aneurysmal SAH treatment is riskier than surgical clipping in terms of re-rupture, vasospasm, or re-stroke. In addition, the independent poor prognostic factors of vasospasm or re-stroke were endovascular coil embolization, male sex, older age (≥65 years; the risk of vasospasm increases with age), hypertension, congestive heart failure, diabetes, previous transient ischemic attack, or stroke in aneurysmal SAH treatment. Background: To estimate the long-term complications and prognostic factors of endovascular coil embolization or surgical clipping for patients with ruptured aneurysmal subarachnoid hemorrhage (SAH). Methods: We selected patients diagnosed with aneurysmal SAH between 1 January 2011 and 31 December 2017. Propensity score matching was performed, and Cox proportional hazards model curves were used to analyze the risk of re-rupture, vasospasm, and re-stroke in patients undergoing the different treatments. Findings: Multivariate Cox regression analysis revealed that the adjusted hazard ratio (aHR) of re-rupture for endovascular coil embolization compared with surgical clipping was 1.36 (95% confidence interval [CI]: 1.17–1.57; p < 0.0001). The aHRs of the secondary endpoints of vasospasm and re-stroke (delayed cerebral ischemia) for endovascular coil embolization compared with surgical clipping were 1.14 (1.02–1.27; p = 0.0214) and 2.04 (1.83–2.29; p < 0.0001), respectively. The independent poor prognostic factors for vasospasm and re-stroke were endovascular coil embolization, male sex, older age (≥65 years; risk increases with age), hypertension, congestive heart failure, diabetes, and previous transient ischemic attack or stroke. Interpretation: Endovascular coil embolization for aneurysmal SAH carries a higher risk than surgical clipping of both short- and long-term complications including re-rupture, vasospasm, and re-stroke.

Nitric Oxide-Based Treatment of Poor-Grade Patients After Severe Aneurysmal Subarachnoid Hemorrhage

Background

Patients with aneurysmal subarachnoid hemorrhage (aSAH) require close treatment in neuro intensive care units (NICUs). The treatments available to counteract secondary deterioration and delayed ischemic events remain restricted; moreover, available neuro-monitoring of comatose patients is undependable. In comatose patients, clinical signs are hidden, and timing interventions to prevent the evolution of a perfusion disorder in response to fixed ischemic brain damage remain a challenge for NICU teams. Consequently, comatose patients often suffer secondary brain infarctions. The outcomes for long-term intubated patients w/wo pupil dilatation are the worst, with only 10% surviving. We previously added two nitroxide (NO) donors to the standard treatment: continuous intravenous administration of Molsidomine in patients with mild-to-moderate aSAH and, if required as a supplement, intraventricular boluses of sodium nitroprusside (SNP) in high-risk patients to overcome the so-called NO-sink effect, which leads to vasospasm and perfusion disorders. NO boluses were guided by clinical status and promptly reversed recurrent episodes of delayed ischemic neurological deficit. In this study, we tried to translate this concept, the initiation of intraventricular NO application on top of continuous Molsidomine infusion, from awake to comatose patients who lack neurological–clinical monitoring but are primarily monitored using frequently applied transcranial Doppler (TCD).

Methods

In this observational, retrospective, nonrandomized feasibility study, 18 consecutive aSAH comatose/intubated patients (Hunt and Hess IV/V with/without pupil dilatation) whose poor clinical status precluded clinical monitoring received standard neuro-intensive care, frequent TCD monitoring, continuous intravenous Molsidomine plus intraventricular SNP boluses after TCD-confirmed macrospasm during the daytime and on a fixed nighttime schedule.

Results

Very likely associated with the application of SNP, which is a matter of further investigation, vasospasm-related TCD findings promptly and reliably reversed or substantially weakened (p < 0.0001) afterward. Delayed cerebral ischemia (DCI) occurred only during loose, low-dose or interrupted treatment (17% vs. an estimated 65% with secondary infarctions) in 17 responders. However, despite their worse initial condition, 29.4% of the responders survived (expected 10%) and four achieved Glasgow Outcome Scale Extended (GOSE) 8–6, modified Rankin Scale (mRS) 0–1 or National Institutes of Health Stroke Scale (NIHSS) 0–2.

Conclusions

Even in comatose/intubated patients, TCD-guided dual-compartment administration of NO donors probably could reverse macrospasm and seems to be feasible. The number of DCI was much lower than expected in this specific subgroup, indicating that this treatment possibly provides a positive impact on outcomes. A randomized trial should verify or falsify our results.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Plasma brain natriuretic peptide level on admission predicts long-term outcome in patients with non-traumatic subarachnoid hemorrhage

INTRODUCTION

Non-traumatic subarachnoid hemorrhage (SAH) is a type of stroke that still has a high mortality rate. Some patients with SAH have electrocardiography (ECG) abnormalities or asymptomatic left ventricular apical ballooning, and requires intervention by cardiologists. However, the impact of cardiac abnormalities after SAH onset remains unclear. We investigated whether ECG abnormalities, myocardial damage, sympathetic nervous activity or echocardiographic left ventricular wall motion abnormalities (WMA) could provide additional risk stratification in patients with SAH.

METHODS

We studied 118 SAH patients (78 women, age 63 ± 15) without a history of heart disease. Neurological grade (Hunt and Kosnik Grade) and clinical factors were evaluated. A standard 12-lead ECG, echocardiography and blood samples were obtained within 48 h after SAH onset. ECG abnormalities were defined as abnormal Q wave, ST elevation, giant T-wave inversion or QT prolongation.

RESULTS

Twenty of 118 patients (17%) died during the follow-up (35 ± 31 months). Death was significantly associated with higher age (p < 0.0001), neurological grade (p < 0.0001), elevated BNP level (p < 0.0001), increased plasma norepinephrine levels (p < 0.0001) and WMA (p = 0.0070), while ECG abnormalities were not significantly associated. Neurological grade (p < 0.0001), age (p = 0.0047) and BNP (p = 0.0014, hazard ratio 1.0255 for each 1 pg/mL increase in BNP, 95%CI 1.0088 to 1.0499) were independently associated with death. Patients with BNP ≥ 96.6 had a higher risk of death (log- rank p < 0.0001).

CONCLUSION

Plasma BNP might provide an additional risk stratification in patients with non-traumatic SAH that requires intervention by cardiologists for both its prevention management after onset.

Temporal evolution of cerebral computed tomography perfusion after acute subarachnoid hemorrhage: a prospective cohort study

Background

Changes in cerebral perfusion occur in subarachnoid hemorrhage that possibly relate to clinical presentation and complications.

Purpose

To evaluate changes in computed tomography perfusion (CTP) parameters between the acute and subacute stage of subarachnoid hemorrhage. To analyze correlation of these parameters to SAH severity and delayed cerebral ischemia.

Material and Methods

Cerebral CT perfusion was assessed in a prospective cohort of 44 patients with acute subarachnoid hemorrhage at < 72 h (CTP1) and 8–10 days (CTP2), using the mean of all regions of interest. Regions of interest were located at arterial territories of the anterior, middle, and posterior cerebral artery and basal ganglia and midpons cerebellar hemispheres. Linear regression models (univariable and multivariable) were used to explore the association between changes in perfusion parameters (absolute and relative differences) and relevant clinical data.

Results

Worse perfusion parameters on the first 72 h were correlated with poor admission clinical scores: cerebral blood flow positively correlated with Glasgow Coma Scale (rS = 0.398, P = 0.008), and negatively correlated with Hunt & Hess scale (rS = −0.348, P = 0.020) and World Federation of Neurosurgeons scale (rS = −0.384, P = 0.010). Cerebral blood volume positively correlated with Glasgow Coma Scale (rS = 0.332, P = 0.028) and negatively correlated with World Federation of Neurosurgeons scale (rS = −0.353, P = 0.019). Mean transit time negatively correlated with Glasgow Coma Scale (rS = −0.415, P = 0.005) and positively correlated with Hunt & Hess scale (rS = 0.471, P = 0.001) and World Federation of Neurosurgeons scale (rS = 0.386, P = 0.010) scores. There were no differences between absolute CTP1/CTP2 parameters. Patients with delayed cerebral ischemia had ΔTmax mean decrease of 2.08 s (95% CI = −4.04–−0.12; P = 0.038).

Conclusion

Early cerebral hypoperfusion correlates with poor clinical grade at admission in subarachnoid hemorrhage and with higher amounts of blood. Tmax was decreased at 8–10 days, in patients with delayed cerebral ischemia, which may favor the application value of Tmax in signaling delayed cerebral ischemia.

Results of a Preventive Rebleeding Protocol in Patients with Ruptured Cerebral Aneurysm: A Retrospective Cohort Study

Objective:

In 2015, a protocol to prevent rebleeding was implemented to improve the outcome of patients with ruptured intracranial aneurysm. We performed a single-center retrospective analysis to compare the outcomes of pre/post using protocol.

Methodology:

Over a 3-year period, 208 patients with ruptured cerebral aneurysm were treated at our institution. The protocol for preventing rebleeding was initiated in 2015. We compared the two cohorts between the group of patients before initiating the protocol (n = 104) and after initiating the protocol (n = 104). We analyzed the protocol for preventing rebleeding which consisted of absolute bed rest, adequate pain control, avoiding stimuli (R), keeping euvolemia (E), preoperative systolic blood pressure <160 mmHg and within 140–180 mmHg after definite treatment (S), a short course (<72 h) of intravenous transaminic acid, and aneurysm treatment as early as possible (T). Outcomes are presented as in-hospital rebleeding, delayed cerebral ischemia (DCI), and proportion of unfavorable outcomes (score of 4–6 on a modified Rankin scale at 6 and 12 months).

Results:

Postprotocol, there was a reduction in the incidence of in-hospital rebleeding from 6.7% to 2.8% (P = 0.20, odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.10–1.63) and in the proportion of patients who presented with good WFNS grades (1–3) with unfavorable clinical outcomes at 12 months from 27.0% to 12.8% (P = 0.03, OR = 0.40, 95% CI = 0.17–0.95). The DCI experienced a significant reduction from 44.2% to 7.7% (P < 0.001, OR = 0.10, 95% CI = 0.04–0.23), and their 180-day mortality rate in good WFNS grades patients decreased from 16.3% to 8.8% (hazard ratio 0.80, 95% CI = 0.28–2.28).

Conclusion:

Ruptured cerebral aneurysm patients benefit from this protocol due to its ability to reduce the incidence of DCI and reduce unfavorable outcome on good WFNS grade patients.

Vessel wall MRI characteristics of endovascularly treated aneurysms: association with angiographic vasospasm

OBJECTIVE

The aim of this paper was to evaluate the association between intracranial vessel wall MRI enhancement characteristics and the development of angiographic vasospasm in endovascularly treated aneurysm patients.

METHODS

Consecutive cases of both ruptured and unruptured intracranial aneurysms that were treated endovascularly, followed by intracranial vessel wall MRI in the immediate postoperative period, were included. Two raters blinded to clinical data and follow-up imaging independently evaluated for the presence, pattern, and intensity of wall enhancement. Development of angiographic vasospasm was independently evaluated. Delayed cerebral ischemia; cerebral infarct; procedural details; and presence and grade of subarachnoid, parenchymal, and intraventricular hemorrhage were evaluated. Statistical associations were determined on a per-vessel segment and per-patient basis.

RESULTS

Twenty-nine patients with 30 treated aneurysms (8 unruptured and 22 ruptured) were included in this study. Interobserver agreement was substantial for the presence of enhancement (κ = 0.67) and nearly perfect for distribution (κ = 0.87) and intensity (κ = 0.84) of wall enhancement. Patients with ruptured aneurysms had a significantly greater number of enhancing segments than those with unruptured aneurysms (29.9% vs 7.2%; OR 5.5, 95% CI 2.2-13.7). For ruptured cases, wall enhancement was significantly associated with subsequent angiographic vasospasm while controlling for grade of hemorrhage (adjusted OR 3.9, 95% CI 1.7-9.4). Vessel segments affected by balloon, stent, or flow-diverter use demonstrated greater enhancement than those not affected (OR 22.7, 95% CI 5.3-97.2 for ruptured; and OR 12.9, 95% CI 3.3-49.8 for unruptured).

CONCLUSIONS

Vessel wall enhancement after endovascular treatment of ruptured aneurysms is associated with subsequent angiographic vasospasm.

Computed tomography perfusion as a predictor of delayed cerebral ischemia and functional outcome in spontaneous subarachnoid hemorrhage: A single center experience

BACKGROUND

Computed tomography (CT) perfusion has been studied as a tool to predict delayed cerebral ischemia (DCI) and clinical outcome in spontaneous subarachnoid hemorrhage (SAH). The purpose of the study was to determine whether quantitative CT perfusion performed within 72 hours after admission can predict the occurrence of DCI and clinical outcome as measured with a modified Rankin scale (mRS) at 3 months after ictus.

METHODS

Cerebral perfusion was assessed in a prospective cohort of patients with acute SAH. CT perfusion parameters at <72 h post SAH were quantitatively measured in the main vascular territories and represented as whole-brain means. Spearman rank correlation coefficient and generalized additive regression models for binary outcome were used.

RESULTS

A total of 66 patients underwent CT perfusion at <72 h. Poor clinical grade on admission was correlated with worse cerebral perfusion in all parameters. Multivariable analysis yielded an association of time to peak (TTP; odds ratio (OR) = 0.89; 95% confidence interval (CI): 0.77, 1.02; p = 0.083) with the occurrence of DCI. We also found an association of TTP values with poor outcome, with an 8% increase in the odds of mRS > 3 for each one second increase in TTP at admission (OR = 1.08; 95% CI: 1.00, 1.17; p = 0.061).

CONCLUSIONS

We identified an association of early TTP changes with DCI and poor clinical outcome. However, there were no associations with cerebral blood flow or mean transit time and DCI/clinical outcome. CT perfusion still remains to be validated as a tool in predicting outcome in SAH.

CT perfusion imaging of cerebral microcirculatory changes following subarachnoid hemorrhage in rabbits: Specific role of endothelin-1 receptor antagonist

BACKGROUND

Cerebral vasospasm may lead to delayed ischemic neurological deficits following subarachnoid hemorrhage (SAH). Endothelin (ET-1) is an important factor participating in cerebral vasospasm underlying SAH. We used a specific endothelin receptor antagonist, BQ123 to assess the specific role of endothelin-1 receptor antagonist in cerebral vasospasm in a rabbit model of SAH by examining plasma ET-1 levels and the principal CT perfusion (CTP) parameters pertinent to the hemodynamic status of microcirculation following SAH.

METHODS

102 male New Zealand white rabbits were divided into control, SAH and SAH + BQ123 intervention group (BQ123 group). Rabbit SAH model was established by double hemorrhage injection of autologous blood into the cisterna magna; Aquilion ONE was used to collect cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) which were used to evaluate cerebral microcirculation hemodynamics; Elisa was used to assess plasma ET-1 levels. Data were collected on days 1, 4, 7 and 14 following SAH, respectively.

RESULTS

Compared with the control group, the CBF in the SAH group was significantly lower, while the MTT was significantly higher. The CBF decreased on the 4th day and reached the lowest on the 7th day. The MTT began to rise on the 4th day and peaked on the 7th day. While in the BQ123 intervention group, the CBF significantly increased while the MTT significantly decreased on the 1st and the 4th days, respectively. Compared with SAH group, plasma ET-1 levels in BQ123 group significantly increased on the earlier (1st and 4th days) but not later days (between the 7th and 14th days). In addition, the inflammatory infiltration of brain tissues in rabbits treated with BQ123 post-SAH was significantly reduced compared with SAH group.

CONCLUSION

CTP can quantify the therapeutic effect of BQ123 after SAH; Selective blockade of ET-1 endothelin receptor, BQ123 significantly improved microcirculatory perfusion along with a reduction in resultant vasogenic inflammatory responses. The effect of BQ123 on the cerebral microcirculation was lobe dependent.

Hemiparesis without Responsible Hematomas in Patients with Subarachnoid Hemorrhage Undergoing Early Aneurysmal Repair

OBJECTIVE

The presence of hemiparesis on arrival in patients with subarachnoid hemorrhage (SAH) is presumed to affect prognosis; intracranial hematomas with mass effect responsible for hemiparesis are frequently observed in these patients. The aim of this study was to clarify characteristics and outcomes of patients who presented with hemiparesis on arrival with no responsible hematomas (hemiparesis without hematoma) having mass effect demonstrated on computed tomography.

METHODS

Consecutive patients with SAH treated with surgery for ruptured cerebral aneurysms within 5 days of onset between 2003 and 2015 were retrospectively reviewed.

RESULTS

Hemiparesis without hematoma was present in 25 of 858 surgically treated patients (2.9%). Internal carotid artery aneurysms were significantly more common in patients with hemiparesis without hematoma than in the other patients (P < 0.05). In 19 of 21 surviving patients (90.5%) with hemiparesis without hematoma on arrival, the hemiparesis improved at discharge. Favorable outcomes were achieved in 16 of 25 patients with hemiparesis without hematoma (64%) and in 13 of 59 patients with hemiparesis with hematomas (22.0%); this difference was significant (P < 0.05).

CONCLUSIONS

Hemiparesis can be expected to improve in patients with SAH with hemiparesis without hematoma, and such patients appear to have a better prognosis than patients with SAH with hemiparesis and responsible hematomas. A possible major mechanism of hemiparesis without hematoma based on the characteristics identified is a combination of transient ipsilateral hemispheric functional failure caused by the impact of aneurysmal rupture and transient ischemia of the perforators originating from the internal carotid artery.

The impact of temporary clipping during aneurysm surgery on the incidence of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE Clipping of a ruptured intracranial aneurysm requires some degree of vessel manipulation, which in turn is believed to contribute to vasoconstriction. One of the techniques used during surgery is temporary clipping of the parent vessel. Temporary clipping may either be mandatory in cases of premature rupture (rescue) or represent a precautionary or facilitating surgical step (elective). The aim of this study was to study the association between temporary clipping during aneurysm surgery and the incidence of vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (aSAH) in a large clinical series. METHODS Seven hundred seventy-eight patients who underwent surgical aneurysm treatment after aSAH were retrospectively included in the study. In addition to surgical parameters, the authors recorded transcranial Doppler (TCD) sonography-documented vasospasm (TCD-vasospasm, blood flow acceleration > 120 cm/sec), delayed ischemic neurological deficits (DINDs), and delayed cerebral infarction (DCI). Multivariate binary logistic regression analysis was applied to assess the association between temporary clipping, vasospasm, DIND, and DCI. RESULTS Temporary clipping was performed in 338 (43.4%) of 778 patients during aneurysm surgery. TCD sonographic flow acceleration developed in 370 (47.6%), DINDs in 123 (15.8%), and DCI in 97 (12.5%). Patients with temporary clipping showed no significant increase in the incidence of TCD-vasospasm compared with patients without temporary clipping (49% vs 48%, respectively; p = 0.60). DINDs developed in 12% of patients with temporary clipping and 18% of those without temporary clipping (p = 0.01). DCI occurred in 9% of patients with temporary clipping and 15% of those without temporary clipping (p = 0.02). The need for rescue temporary clipping was a predictor for DCI; 19.5% of patients in the rescue temporary clipping group but only 11.3% in the elective temporary clipping group had infarcts (p = 0.02). Elective temporary clipping was not associated with TCD-vasospasm (p = 0.31), DIND (p = 0.18), or DCI (p = 0.06). CONCLUSIONS Temporary clipping did not contribute to a higher rate of TCD-vasospasm, DIND, or DCI in comparison with rates in patients without temporary clipping. In contrast, there was an association between temporary clipping and a lower incidence of DINDs and DCI. There is no reason to be hesitant in using elective temporary clipping if deemed appropriate.

Applications of Transcranial Color-Coded Sonography in the Emergency Department

Transcranial color-coded Doppler sonography is a noninvasive bedside ultrasound application that combines both imaging of parenchymal structures and Doppler assessment of intracranial vessels. It may aid in rapid diagnoses and treatment decision making of patients with intracranial emergencies in point-of-care settings. This pictorial essay illustrates the technical aspects and emergency department applications of transcranial color-coded Doppler sonography, and provides some rationale for implementation of this technique into the emergency department practice.

Ultra-Early Angiographic Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

OBJECTIVE

After aneurysmal subarachnoid hemorrhage (aSAH), prognosis is affected heavily by the presence of delayed cerebral ischemia (DCI). There is growing recognition of ultra-early angiographic vasospasm (UEAV) occurring within 48 hours of aSAH; however, its relationship with DCI and ultimately prognosis remains unclear.

METHODS

Various databases limited to the English language through September 2016 were searched systematically. Eligible studies were those comparing UEAV with control non-UEAV outcomes and follow-up. Two independent reviewers evaluated the quality of studies and abstracted the data, with discrepancies resolved by a third. We calculated odds ratios (ORs) and 95% confidence intervals for all outcomes by using random-effects meta-analyses and performed a heterogeneity analysis.

RESULTS

Four comparative studies were selected for analysis. Pooled analysis demonstrated that UEAV compared with no-UEAV was associated with greater proportion of rupture aneurysms sized greater than 12 mm (38.3% vs. 24.3%, P < 0.00001). A significantly greater number of patients with UEAV had ruptured MCA aneurysms compared with patients without UEAV (29.7% vs. 19.9%, P = 0.005). Compared with no-UEAV, patients with UEAV were significantly associated with symptomatic cerebral vasospasm (OR 2.07, P = 0.05) and DCI/infarction (OR 2.52, P = 0.02). A significant association also was found between UEAV and an unfavorable outcome at follow-up (OR 1.64, P = 0.03) and greater mortality (OR 2.65, P < 0.00001).

CONCLUSIONS

UEAV was significantly associated with symptomatic cerebral vasospasm, DCI/infarction, unfavorable outcome at follow-up, and greater mortality. Patients with intracerebral hematoma, intraventricular hemorrhage (Fisher Grade IV), larger ruptured aneurysms >12 mm, and an MCA location were more likely to have UEAV.

Aneurysmal Surgery in the Presence of Angiographic Vasospasm: An Outcome Assessment

Background and Purpose:

The timing of aneurysmal surgery for patients presenting within the period at risk for vasospasm (VS) is controversial. The goal of this study is to review our experience of surgically treated patients in the presence of angiographic VS.

Materials and Methods:

From 1990-2004, 894 consecutive patients presented with an aneurysmal subarachnoid hemorrhage (SAH) and were treated with a policy of early surgery. We retrospectively analyzed the patients that had pre-operative angiographic VS. In this study, symptomatic VS was diagnosed when a decreased level of consciousness and/or focal deficit occurred after SAH in the presence of angiographic VS without confounding factors. Functional outcome was assessed three months after SAH using the Glasgow Outcome Scale.

Results:

Of the 40 patients studied, 62.5% were in good clinical grade Hunt & Hess (H&H 1-2) on admission; 25%, intermediate grade (H&H 3); 12.5%, poor grade (H&H 4-5). Surgery was performed 24 hours or less after initial angiography in 87.5% of patients and less than 48 hours in 97.5%. Pre-operative symptomatic VS was diagnosed in 25%. Postoperatively, angiographic VS was documented in 87.2%. Of the 30% of patients that presented post-operative symptomatic VS, 66.7% also demonstrated pre-operative symptomatic VS. The functional outcome was favorable in 92.5% of the studied patients. Two deaths occurred in patients presenting pre-operative early radiological and symptomatic VS.

Conclusion:

Aneurysmal surgery, especially between 3-12 days following SAH, in the presence of asymptomatic pre-operative angiographic VS can be associated with a good outcome. Early surgery is not contra-indicated and might enable optimal treatment of VS.

Dissociation of Early and Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Background and Purpose—

Cerebral infarction after aneurysmal subarachnoid hemorrhage is a significant cause of substantial morbidity and mortality. Because early and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage may be mediated by different processes, we evaluated whether aneurysm-securing methods contributed to infarcts and whether long-term outcomes differ between early and delayed infarcts.

Methods—

A post hoc analysis of the CONSCIOUS-1 study (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage) was performed. Using multivariate logistic regression analysis and propensity matching, independent clinical risk factors associated with infarctions were identified, and the contribution of cerebral infarcts to long-term outcomes was evaluated.

Results—

Within the cohort of 413 subjects, early infarcts were present in 76 subjects (18%), whereas delayed infarcts occurred in 79 subjects (19%), and 36 subjects (9%) had new infarctions that were present on both early and delayed imaging. Propensity score matching revealed a significantly higher proportion of early infarcts after clipping (odds ratio, 4.62; 95% confidence interval, 1.99–11.57; P =0.00012). Multivariate logistic regressions identified clipping as an independent risk factor for early cerebral infarction (odds ratio, 0.26; 95% confidence interval, 0.15–0.48; P <0.001), and angiographic vasospasm was an independent risk factor for delayed cerebral infarction (odds ratio, 1.79; 95% confidence interval, 1.03–3.13; P =0.039). Early infarcts were a significant independent risk factor for poor long-term outcomes at 3 months (odds ratio, 2.34; 95% confidence interval, 1.18–4.67; P =0.015).

Conclusions—

Clipping is an independent risk factor for the development of early cerebral infarcts, whereas delayed cerebral infarcts are associated with angiographic vasospasm. Early cerebral infarcts are stronger predictors of worse outcome than delayed infarction.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00111085.

Predictors of Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage with Asymptomatic Angiographic Vasospasm on Admission

BACKGROUND

Risk of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) with asymptomatic angiographic vasospasm on admission is unclear in the literature. The goal of this study is to identify predictors of clinical DCI in this group of patients.

METHODS

An exploratory subgroup analysis was conducted in the SAHIT (Subarachnoid Hemorrhage International Trialists) data repository to identify predictors of clinical DCI in patients with good-grade aSAH (World Federation of Neurological Surgeons grade I and II) with angiographic vasospasm on admission. Predictors considered include age, sex, systolic blood pressure at presentation, World Federation of Neurological Surgeon grade, Fisher grade, aneurysm size and location, treatment modality, hydrocephalus requiring external ventricular drain insertion, and severity of vasospasm. The predictors were ranked based on dominance analysis with R² as fit statistics and assessed in a set of logistic regression analysis models.

RESULTS

Four data sets out of 16 studies in the SAHIT database were analyzed, with a total of 4125 patients. One hundred and ninety-one patients (4.6%) had asymptomatic angiographic vasospasm at admission. Of those, 78 patients (40.8%) developed clinical DCI. Univariate analysis showed significant associations between severe vasospasm on admission and development of clinical DCI (odds ratio, 9.5, 95% confidence interval, 2.07-43.50; P = 0.004). None of the studied predictors was associated with the development of clinical DCI on multivariate analysis.

CONCLUSIONS

Asymptomatic angiographic vasospasm in patients with good-grade aSAH on admission is uncommon. Further studies are needed to identify high-risk patients for the development of DCI in the context of asymptomatic early vasospasm.

Failure of Induced Hypertension for Symptomatic Vasospasm in the Setting of Clozapine Therapy

BACKGROUND

Hemodynamic augmentation is utilized as a treatment in the setting of symptomatic cerebral vasospasm. This approach includes the use of vasopressors to induce hypertension with the aim of improved cerebral blood flow. Agents with potent alpha-1 antagonism properties, including clozapine, can inhibit or blunt the response of several vasopressor agents.

METHODS

Case report.

RESULTS

A 54-year-old schizophrenic male with an aneurysmal subarachnoid hemorrhage required hemodynamic augmentation in which several vasopressor trials resulted in no or poor response. The addition of epinephrine resulted in a decrease of mean arterial pressure. Vasopressin initiation demonstrated an immediate vasopressor effect.

CONCLUSIONS

Vasopressors are an important treatment modality in symptomatic cerebral vasospasm. This case highlights the potential for clozapine to blunt the effects of vasopressors; or in the case of epinephrine, it causes a reversal effect. Vasopressin may be considered an agent of choice in patients who have recently taken clozapine and require hemodynamic augmentation.

Focal Neurological Deficit at Onset of Aneurysmal Subarachnoid Hemorrhage: Frequency and Causes

BACKGROUND AND AIM

Focal neurological deficit (FND) is a recognized presenting symptom of aneurysmal subarachnoid hemorrhage (SAH). However, little is known on how often aneurysmal SAH patients present with FND and what the responsible mechanisms are. The aim of this study was to examine the frequency and causes of FND at onset in aneurysmal SAH.

METHODS

We reviewed the records of consecutive aneurysmal SAH patients over 5 years and identified those who presented with FND. We developed several potential mechanisms for FND based on consensus between 2 separate evaluating neurologists. We then compared the characteristics of aneurysmal SAH patients who presented with and without FND. Logistic regression models were used to assess for association of FND with poor outcome.

RESULTS

Of a total of 213 patients, 10.3% presented with FND. The junction of the internal carotid and posterior communicating arteries was the most common aneurysm location in patients with FND (36.4%). Causes of FND at presentation were intraparenchymal hematoma in 45.5%, early cerebral infarction in 22.7%, parenchymal compression by subarachnoid thrombus in 18.2%, and seizure with Todd's paralysis in 13.6%. Patients with FND were older (P = .001) and had higher rates of in-hospital death and severe disability at discharge (P < .0001), compared to those without focal deficit. FND was independently associated with poor outcome (odds ratio: 4.62, confidence interval: 1.41-15.14; P = .01).

CONCLUSION

One in every 10 aneurysmal SAH patients presents with FND. FND at presentation has diverse mechanisms, is not associated with a specific aneurysm location, and is independently associated with poor outcome.

Ultra-early angiographic vasospasm associated with delayed cerebral ischemia and infarction following aneurysmal subarachnoid hemorrhage

OBJECTIVE The clinical significance of cerebral ultra-early angiographic vasospasm (UEAV), defined as cerebral arterial narrowing within the first 48 hours of aneurysmal subarachnoid hemorrhage (aSAH), remains poorly characterized. The authors sought to determine its frequency, predictors, and impact on functional outcome. METHODS The authors prospectively studied UEAV in a cohort of 1286 consecutively admitted patients with aSAH between August 1996 and June 2013. Admission clinical, radiographic, and acute clinical course information was documented during patient hospitalization. Functional outcome was assessed at 3 months using the modified Rankin Scale. Logistic regression and Cox proportional hazards models were generated to assess predictors of UEAV and its relationship to delayed cerebral ischemia (DCI) and outcome. Multiple imputation methods were used to address data lost to follow-up. RESULTS The cohort incidence rate of UEAV was 4.6%. Multivariable logistic regression analysis revealed that younger age, sentinel bleed, and poor admission clinical grade were significantly associated with UEAV. Patients with UEAV had a 2-fold increased risk of DCI (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.4-3.9, p = 0.002) and cerebral infarction (OR 2.0, 95% CI 1.0-3.9, p = 0.04), after adjusting for known predictors. Excluding patients who experienced sentinel bleeding did not change this effect. Patients with UEAV also had a significantly higher hazard for DCI in a multivariable model. UEAV was not found to be significantly associated with poor functional outcome (OR 0.8, 95% CI 0.4-1.6, p = 0.5). CONCLUSIONS UEAV may be less frequent than has been reported previously. Patients who exhibit UEAV are at higher risk for refractory DCI that results in cerebral infarction. These patients may benefit from earlier monitoring for signs of DCI and more aggressive treatment. Further study is needed to determine the long-term functional significance of UEAV.

A Case of Hyperacute Onset of Vasospasm After Aneurysmal Subarachnoid Hemorrhage and Refractory Vasospasm Treated with Intravenous and Intraventricular Nitric Oxide: A Mini Review

BACKGROUND

A case of hyperacute vasospasm, indicating a poor prognosis after aneurysmal subarachnoid hemorrhage (SAH), is reported, and a review is presented of the literature addressing use of nitric oxide (NO) donors in cases of refractory vasospasm and recurrent delayed cortical ischemias (DCI).

CASE DESCRIPTION

A 65-year-old woman was admitted within 1 hour after aneurysmal SAH (Hunt and Hess grade III, Fisher modified by Frontera grade IV). A hyperacute vasospasm had been confirmed arteriographically, the right middle cerebral artery (MCA) aneurysm was immediately coiled and a standard antivasospastic therapy was started. Within 48 hours, the patient developed cerebral vasospasm with DCI. Because the standard therapy failed to control clinical symptoms and to address severe vasospasm, an individualized rescue treatment with NO donors was initiated. A continuous intravenous molsidomine infusion was started and clinical stabilization was achieved for a week (Hunt and Hess grade I; World Federation of Neurological Surgeons grade I; Glasgow Coma Scale score, 15) after which vasospasm and DCI recurred. During a subsequent DCI, we escalated NO donor therapy by adding intraventricular boluses of sodium nitroprusside (SNP). Over the course of the following 22 days, 7 transient DCIs (Glasgow Coma Scale score, 8) were treated with boluses of SNP during continued molsidomine therapy and each time vasospasm and DCI were completely reversed. Despite initial poor prognosis, the clinical outcome was excellent; at 3, 6, and 12 months follow-up the patient's modified National Institutes of Health-Stroke Scale and modified Rankin Scale scores were 0, with no cognitive deficits.

CONCLUSIONS

The review of the literature suggested that combined intravenous molsidomine with intraventricular SNP treatment reversed refractory, recurrent vasospasm and DCIs probably by addressing the hemoglobin NO sink effect, NO depletion, and decreased NO availability after aneurysmal SAH.

Early Vasospasm after Aneurysmal Subarachnoid Hemorrhage Predicts the Occurrence and Severity of Symptomatic Vasospasm and Delayed Cerebral Ischemia

Background: Cerebral vasospasm usually develops several days after subarachnoid hemorrhage (SAH) and is generally acknowledged as a strong outcome predictor. In contrast, much less is known about the nature and eventual consequences of early angiographic vasospasm (EAVS) seen on admission digital subtraction angiography (DSA). Therefore, we aimed at identifying the risk factors and clinical impact of EAVS after SAH. Methods: Five hundred and thirty-one SAH patients with admission DSA performed within 72 h after the bleeding event were selected from a comprehensive database containing all consecutive SAH patients treated at our institution between January 2005 and December 2012. Predictors of EAVS, as well as associations between EAVS and delayed vasospasm-related complications, and unfavorable outcome (defined as modified Rankin scale >3) were evaluated in univariate and multivariate analyses. Results: EAVS was seen on 60 DSAs (11.3%) and was independently correlated with delayed symptomatic vasospasm requiring intra-arterial spasmolysis (OR 5.24, p < 0.0001), angioplasty (OR 2.56, p = 0.015) and repetitive endovascular treatment (OR 4.71, p < 0.0001). EAVS also increased the risk for multiple versus single territorial infarction on the follow-up CT scan(s) (OR 2.04, p = 0.047) and independently predicted unfavorable outcome (OR 2.93, p = 0.008). The presence of radiographic signs suspicious for fibromuscular dysplasia were independently associated with the occurrence of EAVS (OR 2.98, p = 0.026) and the need for repetitive endovascular vasospasm treatment (OR 3.95, p = 0.019). Conclusions: In view of the strong correlation with delayed symptomatic vasospasm and its ischemic complications, EAVS can be considered an alerting signal for severe symptomatic vasospasm. Therefore, more attention should be paid to the presence of EAVS on admission DSA.

Early identification of individuals at high risk for cerebral infarction after aneurysmal subarachnoid hemorrhage: the BEHAVIOR score

Cerebral infarction (CI) is a crucial complication of aneurysmal subarachnoid hemorrhage (SAH) associated with poor clinical outcome. We aimed at developing an early risk score for CI based on clinical characteristics available at the onset of SAH. Out of a database containing 632 consecutive patients with SAH admitted to our institution from January 2005 to December 2012, computed tomography (CT) scans up to day 42 after ictus were evaluated for CIs. Different parameters from admission up to aneurysm treatment were collected with subsequent construction of a risk score. Seven clinical characteristics were independently associated with CI and included in the Risk score (BEHAVIOR Score, 0 to 11 points): Blood on CT scan according to Fisher grade ⩾3 (1 point), Elderly patients (age ⩾55 years, 1 point), Hunt&Hess grade ⩾4 (1 point), Acute hydrocephalus requiring external liquor drainage (1 point), Vasospasm on initial angiogram (3 points), Intracranial pressure elevation >20 mm Hg (3 points), and treatment of multiple aneurysms ('Overtreatment', 1 point). The BEHAVIOR score showed high diagnostic accuracy with respect to the absolute risk for CI (area under curve=0.806, P<0.0001) and prediction of poor clinical outcome at discharge (P<0.0001) and after 6 months (P=0.0002). Further validation in other SAH cohorts is recommended.

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.

Hydrogen-Rich Saline Attenuated Subarachnoid Hemorrhage-Induced Early Brain Injury in Rats by Suppressing Inflammatory Response: Possible Involvement of NF-κB Pathway and NLRP3 Inflammasome

Early brain injury (EBI), highlighted with inflammation and apoptosis, occurring within 72 h after subarachnoid hemorrhage (SAH), is associated with the prognosis of SAH. Recent studies have revealed that hydrogen-rich saline (HS) exerted multiple neuroprotective properties in many neurological diseases including SAH, involved to anti-oxidative and anti-apoptotic effect. We have previously reported that HS could attenuate neuronal apoptosis as well as vasospasm. However, the underlying mechanism of HS on inflammation in SAH-induced EBI remains unclear. In this study, we explored the influence of HS on nuclear factor-κB (NF-κB) pathway and nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome at early stage after SAH, by injecting HS intraperitoneally to SAH rats. One hundred and twenty-nine SD rats were randomly divided into four groups: sham group, SAH group, SAH+vehicle group, and SAH+HS group. SAH model was conducted using endovascular perforation method; all rats were sacrificed at 24 h after SAH. Protein level of pIκBα, cytosolic and nuclear p65, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, interleukin-1β (IL-1β), and cleaved caspase-3 were measured by western blot. mRNA level of IL-1β, interleukin-6 (IL-6), tumor necrosis factor-c (TNF-α) were evaluated by RT-PCR. Cellular injury and death was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Nissl staining, respectively. Our results showed that pIκBα, nuclear p65, NLRP3, ASC, caspase-1, IL-1β, cleaved caspase-3 proteins, as well as the mRNA of IL-1β, IL-6, and TNF-ɑ increased at 24 h after SAH, while cytosolic p65 decreased. TUNEL and Nissl staining presented severe cellular injury at 24 h post-SAH. However, after HS administration, the changes mentioned above were reversed. In conclusion, HS may inhibit inflammation in EBI and improve neurobehavioral outcome after SAH, partially via inactivation of NF-κB pathway and NLRP3 inflammasome. Graphical Abstract Schematic representation of the mechanism of HS-mediated anti-inflammatory effect in EBI after SAH. The NF-κB inflammatory pathway and NLRP3 inflammasome are involved in the anti-neuroinflammatory effect of HS post-SAH. SAH-induced oxidative stress enhances the activation of NF-κB, thus promoting the translocation of p65 subunit into nucleus and increasing the mRNA level of its downstream proinflammatory cytokines (IL-1β, IN-6, TNF-α) and NLRP3. Elevated expression of NLRP3 mRNA increases the assembly of NLRP3 inflammasome. In addition, oxidative stress after SAH stimulates the activation of NLRP3 inflammasome, therefore, promoting caspase-1 activation and the cleavage of pro-IL-1β into mature IL-1β. Finally, activation of NF-κB pathway and NLRP3 inflammasome contribute to the inflammation response and cellular injury in EBI after SAH. HS treatment reversed the detrimental effect mentioned above via inactivation of NF-κB pathway and NLRP3 inflammasome. NF-κB nuclear factor-κB, IκB inhibitor of NF-κB, IKK Iκ kinase, NLRP3 nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3, ASC apoptosis-associated speck-like protein containing a caspase recruitment domain.

Cerebral vasospasm

Cerebral vasospasm causes delayed ischemic neurologic deficits after aneurysmal subarachnoid hemorrhage. This is a well-established clinical entity with significant associated morbidity and mortality. The underlying patholphysiology is highly complex and poorly understood. Large-vessel vasospasm, autoregulatory dysfunction, inflammation, genetic predispositions, microcirculatory failure, and spreading cortical depolarization are aspects of delayed neurologic deterioration that have been described in the literature. This article presents a perspective on cerebral vasospasm, as guided by the literature to date, specifically examining the mechanism, diagnosis, and treatment of cerebral vasospasm.

Cerebral vasospasm and delayed cerebral ischemia in intraventricular hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) with intraventricular extension (IVH) is a devastating disease with a particular high mortality. In some aspects, IVH may resemble subarachnoid hemorrhage. The incidence and role of cerebral vasospasm in ICH with IVH are poorly understood. Here, we aimed to analyze the incidence and relationship of cerebral vasospasm to clinical characteristics, in-hospital mortality, and functional outcome at 3 months in patients suffering ICH with IVH.

METHODS

Patients with ICH and IVH treated on a neurological intensive care unit were prospectively enrolled in a single-center observational study. Vasospasm was defined using established ultrasound criteria. Delayed cerebral ischemia (DCI) was defined as a new hypodensity on follow-up cranial CT. Functional outcome at 3 months was assessed using the modified Rankin Scale.

RESULTS

129 patients with ICH and IVH were screened for the study. 62 patients entered the final analysis. The incidence of significant vasospasm was 37 %. A strong trend was found for the association between all cerebral vasospasm and DCI (P = 0.046). Early (up to 48 h) vasospasm was significantly associated with a DCI (P = 0.033). Overall mortality and outcome after 3 months did not differ between the groups.

CONCLUSION

Cerebral vasospasm seems to be a frequent complication after ICH with IVH and might be associated with DCI. Larger studies are warranted to confirm this hypothesis.

Redefining secondary injury after subarachnoid hemorrhage in light of multimodal advanced neuroimaging, intracranial and transcranial neuromonitoring: beyond vasospasm

The classic idea that arterial narrowing, called vasospasm (VSP), represents the hallmark of secondary injury after subarachnoid hemorrhage, has been challenged. The more complex and pleiotropic pathophysiological repercussions from the irruption of arterial blood into the subarachnoid layers go beyond the ascribed VSP. Putting adjectives in front of this term, such as "symptomatic," "microdialytic," or "angiographic" VSP, is misleading. Delayed cerebral ischemia (DCI) is a better term but remains restrictive to severe hypoperfusive injury and neglects oligemia, edema, and metabolic nonischemic injuries. In recognition of these issues, the international conference on VSP integrated "neurovascular events" into its name ( www.vasospasm2013.com ) and a multidisciplinary research group was formed in 2010 to study subgroups of DCI/VSP and their respective significance.In three parts, this tiered article provides a broader definitional envelope for DCI and secondary neurovascular insults after SAH, with a rubric for each subtype of delayed neuronal dysfunction. First, it pinpoints the need for nosologic precision and covers current terminological inconsistency. Then, it highlights the input of neuroimaging and neuromonitoring in defining secondary injurious processes. Finally, a new categorization of deteriorating patients is proposed, going beyond a hierarchical or dichotomized definition of VSP/DCI, and common data elements are suggested for future trials.

Acute angiographic vasospasm and the incidence of delayed cerebral vasospasm: preliminary results

BACKGROUND

More than half of subarachnoid hemorrhage (SAH) patients develop angiographically detectable delayed cerebral vasospasm (dCVS). It mostly occurs between days 4 and 15 after ictus and can be associated with neurological deficits that contribute to increased morbidity and mortality after SAH. Although dCVS is well studied, there are only a handful of reports on the acute phase of vasospasm (APV) occurring after treatment of intracranial aneurysms, whether ruptured or not. The aim of the current study is to elucidate the association of intraoperative cerebral vasospasm (iCVS) with the incidence of dCVS.

METHOD

We retrospectively reviewed consecutive patients who were treated for aneurysmal SAH or incidental aneurysms during the study period. Angiograms of patients undergoing aneurysm treatment were reviewed. Spasm severity was classified with respect to reduction in the transverse diameter. Mild vasospasm was defined as a reduction in vessel diameter of 10-30 %; moderate, 30-50 %; and severe vasospasm, >50 %. Statistical significance was tested using the Χ² test with p < 0.05. Correlations between iCVS and other factors were investigated.

RESULTS

Of 109 patients, 77 patients (33 men and 44 women) presented with acute SAH and 32 patients (9 men and 23 women) were treated for incidental aneurysms. Seventeen (22 %) of 77 patients presenting with acute SAH had evidence of acute (within 72 h after SAH ictus) CVS. In 16 of 17 (94.1 %) patients, this vasospasm was observed immediately after treatment and was therefore termed iCVS. Eleven (30 %) of 36 patients undergoing clipping and 5 (14 %) of 36 patients with endovascular aneurysm occlusion had iCVS (p = 0.07). Patients presenting with acute SAH had a higher incidence of iCVS than patients undergoing elective aneurysm treatment (p = 0.02). Only one patient (3 %) had iCVS in the elective treatment group whereas 16 (20 %) had iCVS after SAH. The incidence of dCVS, delayed ischemic neurological deficits (DNDs), and poor outcome in patients presenting with iCVS during surgical treatment of ruptured aneurysms was 56 % (p = 0.001), 63 % (p = 0.02), and 38 % (p = 0.14), respectively.

CONCLUSION

APV exists and is a common finding in patients with SAH. Further studies are warranted to correlate the presence of APV with postoperative ischemia, dCVS, and outcome.

Current options for the management of aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm: a comprehensive review of the literature

OBJECTIVES

Cerebral vasospasm is one of the leading causes of morbi-mortality following aneurysmal subarachnoid hemorrhage. The aim of this article is to discuss the current status of vasospasm therapy with emphasis on endovascular treatment.

METHODS

A comprehensive review of the literature obtained by a PubMed search. The most relevant articles related to medical, endovascular and alternative therapies were selected for discussion.

RESULTS

Current accepted medical options include the oral nimodipine and 'triple-H' therapy (hypertension, hypervolemia and hemodilution). Nimodipine remains the only modality proven to reduce the incidence of infarction. Although widely used, 'triple-H' therapy has not been demonstrated to significantly change overall outcome after cerebral vasospasm. Indeed, both induced hypervolemia and hemodilution may have deleterious effects, and more recent physiologic data favor normovolemia with induced hypertension or optimization of cardiac output. Endovascular options include percutaneous transluminal balloon angioplasty (PTA) and intra-arterial (IA) infusion of vasodilators. Multiple case reports and case series have been encountered in the literature using different drug regimens with diverse mechanisms of action. Compared with PTA, IA drug infusion has the advantages of distal penetration and a better safety profile. Its main disadvantages are the more frequent need for repeat treatments and its systemic hemodynamic repercussions. Alternative options using intraventricular/cisternal drug therapy and flow augmentation strategies have also shown possible benefits; however, their use is not yet as well established.

CONCLUSION

Blood pressure or cardiac output optimization should be the mainstay of hyperdynamic therapy. Endovascular treatment appears to have a positive impact on neurological outcome compared with the natural history of the disease. The role of intraventricular therapy and flow augmentation strategies in association with medical and endovascular treatment may, in the future, play a growing role in the management of patients with severe refractory vasospasm.

The role of arterioles and the microcirculation in the development of vasospasm after aneurysmal SAH

Cerebral vasospasm of the major cerebral arteries, which is characterized by angiographic narrowing of those vessels, had been recognized as a main contributor to delayed cerebral ischemia (DCI) in subarachnoid hemorrhage (SAH) patients. However, the CONSCIOUS-1 trial revealed that clazosentan could not improve mortality or clinical outcome in spite of successful reduction of relative risk in angiographic vasospasm. This result indicates that the pathophysiology underlying DCI is multifactorial and that other pathophysiological factors, which are independent of angiographic vasospasm, can contribute to the outcome. Recent studies have focused on microcirculatory disturbance, such as microthrombosis and arteriolar constriction, as a factor affecting cerebral ischemia after SAH. Reports detecting microthrombosis and arteriolar constriction will be reviewed, and the role of the microcirculation on cerebral ischemia during vasospasm after SAH will be discussed.

The role of microglia and the TLR4 pathway in neuronal apoptosis and vasospasm after subarachnoid hemorrhage

BACKGROUND

Although microglia and the Toll-like receptor (TLR) pathway have long been thought to play a role in the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH), thus far only correlations have been made. In this study, we attempted to solidify the relationship between microglia and the TLR pathway using depletion and genetic knockouts, respectively.

METHODS

Subarachnoid hemorrhage was induced in TLR4-/-, TRIF-/-, MyD88-/- and wild type C57BL/6 mice by injecting 60 μl of autologous blood near the mesencephalon; animals were euthanized 1 to 15 days after SAH for immunohistochemical analysis to detect microglia or apoptotic cells. Lastly, microglial depletion was performed by intracerebroventricular injection of clodronate liposomes.

RESULTS

On post operative day (POD) 7 (early phase SAH), neuronal apoptosis was largely TLR4-MyD88-dependent and microglial-dependent. By POD 15 (late phase SAH), neuronal apoptosis was characterized by TLR4- toll receptor associated activator of interferon (TRIF)-dependence and microglial-independence. Similarly, vasospasm was also characterized by an early and late phase with MyD88 and TRIF dependence, respectively. Lastly, microglia seem to be both necessary and sufficient to cause vasospasm in both the early and late phases of SAH in our model.

CONCLUSION

Our results suggest that SAH pathology could have different phases. These results could explain why therapies tailored to aSAH patients have failed for the most part. Perhaps a novel strategy utilizing immunotherapies that target Toll like receptor signaling and microglia at different points in the patient's hospital course could improve outcomes.