Plasma SPARC Elevation in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

Matricellular proteins have been implicated in pathologies after subarachnoid hemorrhage (SAH). To find a new therapeutic molecular target, the present study aimed to clarify the relationships between serially measured plasma levels of a matricellular protein, secreted protein acidic and rich in cysteine (SPARC), and delayed cerebral ischemia (DCI) in 117 consecutive aneurysmal SAH patients with admission World Federation of Neurological Surgeons (WFNS) grades I-III. DCI developed in 25 patients with higher incidences of past history of hypertension and dyslipidemia, preoperative WFNS grade III, modified Fisher grade 4, spinal drainage, and angiographic vasospasm. Plasma SPARC levels were increased after SAH, and significantly higher in patients with than without DCI at days 7-9, and in patients with VASOGRADE-Yellow compared with VASOGRADE-Green at days 1-3 and 7-9. However, there were no relationships between plasma SPARC levels and angiographic vasospasm. Receiver-operating characteristic curves differentiating DCI from no DCI determined the cut-off value of plasma SPARC ≥ 82.1 ng/ml at days 7 - 9 (sensitivity, 0.800; specificity, 0.533; and area under the curve, 0.708), which was found to be an independent determinant of DCI development in multivariate analyses. This is the first study to show that SPARC is upregulated in peripheral blood after SAH, and that SPARC may be involved in the development of DCI without angiographic vasospasm in a clinical setting.

External Validation of an Extreme Gradient Boosting Model for Prediction of Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) may significantly worsen the functional status of patients with aneurysmal subarachnoid hemorrhage (aSAH). Several authors have designed predictive models for early identification of patients at risk of post-aSAH DCI. In this study, we externally validate an extreme gradient boosting (EGB) forecasting model for post-aSAH DCI prediction.

METHODS

A 9-year institutional retrospective review of patients with aSAH was performed. Patients were included if they underwent surgical or endovascular treatment and had available follow-up data. DCI was diagnosed as new onset neurological deficits at 4-12 days after aneurysm rupture, defined as worsening GCS for ≥2 points, and new ischemic infarcts at imaging.

RESULTS

267 patients with aSAH were collected. At admission, median Hunt-Hess score was 2 (range, 1-5), median Fisher score 3 (range, 1-4), and median modified Fisher score 3 (range, 1-4). 145 patients underwent EVD placement for hydrocephalus (54.3%). The ruptured aneurysms were treated with clipping (64%), coiling (34.8%), and stent-assisted coiling (1.1%). 58 patients (21.7%) were diagnosed with clinical DCI and 82 (30.7%) with asymptomatic imaging vasospasm. The EGB classifier correctly predicted 19 cases of DCI (7.1%) and 154 cases of no-DCI (57.7%), achieving sensitivity of 32.76% and specificity of 73.68%. The calculated F1-score and accuracy were 0.288 and 64.8%, respectively.

CONCLUSION

We validated the EGB model has a potential assistant tool to predict post-aSAH DCI in clinical practice, finding moderate-high specificity but low sensitivity. Future research should investigate the underlying pathophysiology of DCI to allow the development of high-performing forecasting models.

Different Risk Factors Between Cerebral Infarction and Symptomatic Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Cerebral infarction due to cerebral vasospasm (IVS) after aneurysmal subarachnoid hemorrhage is associated with poor outcomes and symptomatic cerebral vasospasm (SVS). However, the difference of risk factors between SVS and IVS was unclear to date. In this study, we aimed to elucidate the risk factors for SVS and IVS based on the registry study.

METHODS

The modified World Federation of Neurosurgical Societies scale study comprises 1863 cases. Patients with aneurysmal subarachnoid hemorrhage who underwent radical treatment within 72 hours with a premorbid modified Rankin Scale score 0-2 as the inclusion criteria were retrospectively examined. The risk factors for SVS and IVS were analyzed using multivariable logistic regression analysis.

RESULTS

Among them, 1090 patients who met the inclusion criteria were divided into 2 groups according to SVS and IVS; 273 (25%) patients with SVS and 92 (8.4%) with IVS. Age was not a risk factor for SVS, but for IVS, and Fisher scale was a risk factor for SVS, but not for IVS.

CONCLUSIONS

The prevalence of IVS was not associated with the Fisher scale but with older age, suggesting possible factors other than SVS. Different associated factors between SVS and IVS were confirmed in this study.

Volatile Sedation With Isoflurane in Neurocritical Care Patients After Poor-grade Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Volatile sedation after aneurysmal subarachnoid hemorrhage (aSAH) promises several advantages, but there are still concerns regarding intracranial hypertension due to vasodilatory effects. We prospectively analyzed cerebral parameters during the switch from intravenous to volatile sedation with isoflurane in patients with poor-grade (World Federation of Neurosurgical Societies grade 4-5) aSAH.

METHODS

Eleven patients were included in this prospective observational study. Between day 3 and 5 after admission, intravenous sedation was switched to isoflurane using the Sedaconda Anesthetic Conserving Device (Sedana Medical, Danderyd, Sweden). Intracranial pressure (ICP), cerebral perfusion pressure (CPP), brain tissue oxygenation (PBrO₂), cerebral mean flow velocities (MFVs; transcranial Doppler ultrasound) and regional cerebral oxygen saturation (rSO₂, near-infrared spectroscopy monitoring), as well as cardiopulmonary parameters were assessed before and after the sedation switch (-12 to +12 hours). Additionally, perfusion computed tomography data during intravenous and volatile sedation were analyzed retrospectively for changes in cerebral blood flow.

RESULTS

There were no significant changes in mean ICP, CPP, and PBrO₂ after the sedation switch to isoflurane. Mean rSO₂ showed a non-significant trend towards higher values, and mean MFV in the middle cerebral arteries increased significantly after the initiation of volatile sedation. Isoflurane sedation resulted in a significantly increased norepinephrine administration. Despite an increase in mean inspiratory pressure, we observed a significant increase in mean partial arterial pressure of carbon dioxide.

CONCLUSIONS

Isoflurane sedation does not compromise ICP or cerebral oxygenation in poor-grade aSAH patients, but the significant depression of CPP could limit the use of volatiles in case of hemodynamic instability or high vasopressor demand.

Higher Levels of Admission N-Terminal Pro-brain Natriuretic Peptide are Associated with Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) greatly influences the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to determine whether higher levels of admission N-terminal pro-brain natriuretic peptide (NT-pro BNP) were related to neurogenic cardiac injury and predicted DCI occurrence in patients with aSAH.

METHODS

We retrospectively reviewed consecutive patients with aSAH between January 2018 and April 2021 in our department. Patients with admission NT-pro BNP were included for analysis. The associations between admission NT-pro BNP levels and admission cardiac troponin T levels and electrocardiogram characteristics, as well as the incidence of DCI, were investigated.

RESULTS

A total of 415 patients with aSAH were included, among whom DCI occurred in 53 (12.8%). The admission NT-pro BNP levels were positively correlated with the cardiac troponin T levels and were significantly higher in patients with abnormal electrocardiogram characteristics. The admission log NT-pro BNP levels were higher in patients with DCI than in those without DCI. Multivariable analysis revealed that admission log NT-pro BNP levels and modified Fisher scale were independent predictors of the incidence of DCI. Compared with the modified Fisher scale alone (area under the curve = 0.739), combining the modified Fisher scale with admission NT-pro BNP (area under the curve = 0.794) significantly improved the prediction accuracy for DCI (p < 0.001).

CONCLUSIONS

Higher admission levels of NT-pro BNP correlated with neurogenic cardiac injury and predicted the occurrence of DCI in patients with aSAH. A combination of the modified Fisher scale and admission NT-pro BNP significantly improved the prediction accuracy for DCI.

The Role of VASOGRADE as a Simple Grading Scale to Predict Delayed Cerebral Ischemia and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The VASOGRADE is a simple aneurysmal subarachnoid hemorrhage (aSAH) grading scale that combines the modified Fisher scale (mFisher) and the World Federation of Neurological Societies (WFNS) grading system, allowing the stratification of delayed cerebral ischemia (DCI) risk. However, the VASOGRADE accuracy in predicting functional outcomes is still to be determined.

METHODS

We retrospectively evaluated a multiethnic cohort of consecutive patients with aSAH admitted to a high-volume center in Brazil from January 2016 to January 2019. Patients were classified according to the severity of the clinical presentation (WFNS), the amount of blood in the initial head computerized tomography (mFisher) scan, and the VASOGRADE (green, yellow, red). The primary outcome was to detect DCI-related cerebral infarction, and the secondary outcome was the functional outcome at hospital discharge according to the modified Rankin scale (mRs). Univariate and multivariate logistic regression models were employed.

RESULTS

A total of 212 patients (71.7% female, mean age 52.7 ± 12.8) were included. Sixty-nine patients were classified as VASOGRADE-Green (32.5%), 98 patients as VASOGRADE-Yellow (46.9%), and 45 patients as VASOGRADE-Red (20.6%). DCI-related infarction was present in 39 patients (18.9%). The proportions of patients in the VASOGRADE-Green, VASOGRADE-Yellow, and VASOGRADE-Red categories with DCI-related infarction were 7.7, 61.5, and 30.8%, respectively. After a multivariable analysis including age, sex, aneurysm location, and the VASOGRADE classification as variables, both VASOGRADE-Yellow and VASOGRADE-Red were independently associated with DCI-related infarction (odds ratio [OR] 7.69, 95% confidence interval [CI] 2.13-27.8, and OR 8.07, 95% CI 2.03-32.11, respectively) and unfavorable outcome (OR 4.16, 95% CI 1.33-13.03, and OR 25.57, 95% CI 4.45-147.1, respectively). The VASOGRADE discrimination performance for DCI-related infarction (area under the receiver operating characteristic curve) was 0.67 ± 0.04 (95% CI 0.58-0.75; p = 0.001). VASOGRADE-Red had 97.5% specificity for predicting an unfavorable mRs score at discharge (95% CI 92.8-99.5%). Conversely, VASOGRADE-Green had an excellent specificity for predicting favorable outcome at discharge (mRs score 0-2, 95% CI 82.6-95.5%).

CONCLUSIONS

In conclusion, in a multiethnic cohort of patients with aSAH, VASOGRADE-Green predicted the absence of DCI and good clinical outcome at discharge with very high specificity, and patients in this category might be selected for early intensive care unit (ICU) discharge, minimizing costs and medical complications associated with prolonged hospital stay. On the other hand, patients categorized as VASOGRADE-Yellow and VASOGRADE-Red were at the highest risk for DCI. They should, therefore, be selected as a priority for care in high-volume aSAH centers, being aggressively monitored for DCI at the ICU. Such stratification methods are crucial, especially in countries with low financial resources and high health care services demand.

Cerebrospinal Fluid Lactate and Glucose Levels as Predictors of Symptomatic Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a complex neurovascular syndrome with profound systemic effects associated with high rates of disability and mortality. Delayed cerebral ischemia (DCI), which encompasses all neurobiological events occurring in the subacute-late stage after aSAH, has a complex pathogenesis and can occur in the absence of instrumental vasospasm. Our aim was to assess the correlation between cerebrospinal fluid (CSF) lactate and glucose levels measured on the second or third day after aSAH with clinical deterioration caused by DCI and with 3-month functional outcome.

METHODS

This prospective study included all aSAH patients admitted between January 2020 and December 2021 who underwent external ventricular drain placement and CSF lactate and glucose measurement.

RESULTS

Among 133 aSAH patients, 48 had an external ventricular drain placed and early CSF lactate and glucose assessment. Independent predictors of symptomatic DCI were World Federation of Neurosurgical Societies grade IV-V (adjusted odds ratio [aOR] 25.8, 95% confidence interval [CI] 2.9-649.2, P = 0.012), elevated CSF glucose (aOR 28.8, 95% CI 3.3-775.2, P = 0.010), and elevated CSF lactate (aOR 14.7, 95% CI 1.9-205.7, P = 0.018). The only independent predictor of 3-month functional outcome was occurrence of symptomatic DCI (aOR 0.02, 95% CI 0.0-0.2, P = 0.01).

CONCLUSIONS

Elevated CSF lactate and glucose levels in the first 3 days following aSAH were independent predictors of subsequent DCI-related neurological impairment; the presence of instrumental vasospasm was not significantly correlated with DCI after multivariate adjustment. CSF lactate and glucose monitoring may represent a point-of-care test, which could potentially improve prediction of subacute neurological worsening and guide therapeutic choices. Further research with larger prospective cohorts is warranted.

Effect of Surgical Clipping versus Endovascular Coiling on the Incidence of Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage: A Multicenter Observational Cohort Study with Propensity Score Matching

OBJECTIVE

The effect of surgical clipping (SC) and endovascular coiling (EC) on the incidence of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) has always been a controversial topic. Hence, it is necessary to reanalyze the effects of the 2 surgical methods on DCI, which determines the choice of the most favorable method for patients who are suitable for both surgical modalities.

METHODS

A multicenter retrospective observational cohort study was performed to evaluate all consecutive patients with aSAH admitted to 5 medical centers in China between April 2019 and June 2021. Univariable and multivariable analyses were used to confirm risk factors of DCI after aSAH. A 1:1 propensity score matching model was generated in the EC and SC groups to reduce the influence of all confounding factors on DCI.

RESULTS

A total of 412 patients were included, and 115 patients (27.9%) developed DCI. After propensity score matching for controlling demographic information, past medical history, admission clinical status, aneurysm characteristics, and inflammatory factors associated with DCI, 133 patients with SC and 133 patients with EC treatment were matched. The results of the matched cohorts indicate a significantly lower incidence of DCI when patients received EC than SC (31.9% vs. 20%; adjusted odds ratio, 1.87; 95% confidence interval, 1.08-3.29; P = 0.027).

CONCLUSIONS

The study found that the patients who received SC treatment had a higher incidence of DCI than did those who received EC and suggested that ruptured intracerebral aneurysm is preferentially coiled rather than clipped if the aneurysm is suitable for both surgical modalities.

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

INTRODUCTION

Angiographic vasospasm (VSP), the narrowing of intracranial arteries, is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and often results in delayed cerebral ischemia (DCI) and cerebral infarction. The objective of this systematic review was to summarize the clinical burden of angiographic VSP and its related complications (DCI and cerebral infarction) after aSAH.

METHODS

Systematic searches of MEDLINE, Embase, and the Cochrane Library were conducted (in January 2021) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies reporting clinical outcomes of angiographic VSP and its related complications after aSAH. Study outcomes included measures of functional status (modified Rankin Scale [mRS], Glasgow Outcome Scale [GOS], extended Glasgow Outcome Scale [GOS-E], modified Barthel Index, or the modified National Institutes of Health Stroke Scale), cognitive status (Montreal Cognitive Assessment or the Mini Mental State Exam), clinical events (rebleeding), and mortality. Study selection, data extraction, and qualitative analyses were conducted.

RESULTS

Of 5704 abstracts reviewed, 110 studies were selected: 20 comparative and 39 regression-based studies were included in the qualitative synthesis, 51 descriptive studies were excluded. Most studies (51) were observational and conducted in a single country (53). The occurrence of angiographic VSP and its related complications after aSAH resulted in significantly poorer functional outcomes in three of nine comparative and 11 of 13 regression-based studies, measured by the mRS, and in five of six comparative and eight of nine regression-based studies, measured by the GOS and GOS-E. Angiographic VSP and its related complications were significantly associated with poor cognitive status in all five regression-based studies. Numerically or significantly higher mortality rates in patients with versus those without angiographic VSP and its related complications were reported in five of ten comparative studies and in eight of nine regression-based studies. Six studies looked at specific VSP populations (e.g., by severity or timing of VSP).

CONCLUSION

Patients with angiographic VSP and its related complications often had poor functional, neurological, and cognitive outcomes and reduced odds of survival both in hospital and at follow-up. We estimate that angiographic VSP and its related complications, DCI and cerebral infarction, lead to an approximately threefold higher odds of poor functional and cognitive outcomes, and about a twofold increase in the odds of death.

Association of hemoglobin trend and outcomes in aneurysmal subarachnoid hemorrhage: A single center cohort study

BACKGROUND

Anemia has been linked to delayed cerebral ischemia (DCI) and worse outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, the association of hemoglobin (Hb) trend and outcomes is not well studied. We investigated predictors of Hb trend and its association with outcomes in patients with aSAH. Our hypothesis was that a negative Hb trend is associated with poorer outcomes independent of Hb values.

METHODS

We conducted a retrospective study of a prospectively collected cohort of consecutive patients with aSAH who were admitted to an academic center (2016-2021). We tested the association of Hb trend and values with measures including DCI and poor functional outcome defined as modified Rankin scale 4-6 at 3 months after discharge. Multiple linear regression analysis was used to identify factors associated with Hb difference from admission to discharge.

RESULTS

We included 310 patients with confirmed aneurysmal etiology (mean age 57 years, SD13.6; 62 % female). Greater Hb decrement from admission to discharge was independently associated with higher likelihood of both DCI (OR 1.28 per 1 g/dl decrease in Hb, 95 % CI 1.08-1.47; p = 0.003) and poor functional outcome (OR 1.27 per 1 g/dl decrease in Hb, 1.03-1.53; p = 0.026) independent of any absolute Hb values. Predictors of Hb decrement from admission to discharge were hospital length of stay, Hunt and Hess grades, female sex and age.

CONCLUSION

Greater Hb decrement can be associated with higher likelihood of DCI and poor functional outcome in aSAH. More evidence is needed to use Hb trend to guide transfusion threshold in aSAH patients.

A prospective cohort study on serum A20 as a prognostic biomarker of aneurysmal subarachnoid hemorrhage

BACKGROUND

A20 may be a neuroprotective factor. Herein, we aimed to investigate whether serum A20 levels were associated with disease severity, delayed cerebral ischemia (DCI), and outcome after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

In this prospective cohort study containing 112 aSAH patients and 112 controls, serum A20 levels were quantified. At 90 d poststroke, Modified Rankin Scale (MRS) scores ≥3 were defined as a poor outcome. All correlations and associations were assessed using multivariate analysis.

RESULTS

Compared with controls, there was a significant elevation of serum A20 levels in patients (median 123.7 pg/mL vs. 25.8 pg/mL; P<0.001). Serum A20 levels were independently correlated with Hunt-Hess scores (β 9.854; 95% confidence interval [95% CI] 2.481-17.227, P=0.009) and modified Fisher scores (β 10.349, 95% CI 1.273-19.424, P=0.026). Independent associations were found between serum A20 levels and poor outcome (odds ratio [OR] 1.015, 95% CI 1.000-1.031, P=0.047) and DCI (OR 1.018, 95% CI 1.001-1.035, P=0.042). Areas under the curve for predicting poor outcome and DCI were 0.771 (95% CI 0.682-0.845) and 0.777 (95% CI 0.688-0.850), respectively. Serum A20 levels ≥128.15 pg/mL predicted poor outcome, with a sensitivity of 73.9% and specificity of 74.2%, and A20 levels ≥160.55 pg/mL distinguished the risk of DCI with 65.5% sensitivity and 89.2% specificity. Its ability to predict poor outcome and DCI was similar to those of Hunt-Hess scores and modified Fisher scores (both P>0.05).

CONCLUSION

Enhanced serum A20 levels are significantly associated with stroke severity and poor clinical outcome after aSAH, implying that serum A20 may be a potential prognostic biomarker for aSAH.

Hydrocephalus, cerebral vasospasm, and delayed cerebral ischemia following non-aneurysmatic spontaneous subarachnoid hemorrhages: an underestimated problem

Non-aneurysmal subarachnoid hemorrhage (NASAH) is rare and mostly benign. However, complications such as cerebral vasospasm (CV), delayed cerebral ischemia (DCI), or post-hemorrhagic hydrocephalus (HC) may worsen the prognosis. The aim of this study was to evaluate the rate of these complications comparing perimesencephalic (PM) and non-perimesencephalic (NPM) SAH. Monocentric, retrospective analysis of patients diagnosed with NASAH from 01/2010 to 01/2021. Diagnosis was set only if vascular pathologies were excluded in at least one digital subtraction angiography, and NASAH was confirmed by cranial computed tomography (cCT) or lumbar puncture (LP). One hundred patients (62 female) with a mean age of 54.9 years (27-84) were identified. Seventy-three percent had a World Federation of Neurological Surgeons (WFNS) grading scale score I, while 9% were WFNS score IV or V at the time of admission. SAH was diagnosed by cCT in 86%, in 14% by lumbar puncture. Twenty-five percent necessitated short-term CSF diversion by extraventricular drainage or lumbar drainage, whereof 7 suffered from long-term HC treated with ventriculoperitoneal shunting (VPS). One patient without a short-term CSF drainage developed long-term HC. Ten percent developed CV, four of whom received intraarterial spasmolysis. Radiological DCI was diagnosed in 2%; none of these correlated with CV. Despite a mortality of 3% occurring solely in NPM SAH, the analyzed complication rate was comparable in both groups. We observed post-hemorrhagic complications in 35% of cases during the first 3 weeks after bleeding, predominantly in patients with NPM SAH. For this reason, close observation and cranial imaging within this time may be indicated not to overlook these complications.

The REACT study: design of a randomized phase 3 trial to assess the efficacy and safety of clazosentan for preventing deterioration due to delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

For patients presenting with an aneurysmal subarachnoid hemorrhage (aSAH), delayed cerebral ischemia (DCI) is a significant cause of morbidity and mortality. The REACT study is designed to assess the safety and efficacy of clazosentan in preventing clinical deterioration due to DCI in patients with aSAH.

METHODS

REACT is a prospective, multicenter, randomized phase 3 study that is planned to enroll 400 patients with documented aSAH from a ruptured cerebral aneurysm, randomized 1:1 to 15 mg/hour intravenous clazosentan vs. placebo, in approximately 100 sites and 15 countries. Eligible patients are required to present at hospital admission with CT evidence of significant subarachnoid blood, defined as a thick and diffuse clot that is more than 4 mm in thickness and involves 3 or more basal cisterns. The primary efficacy endpoint is the occurrence of clinical deterioration due to DCI up to 14 days post-study drug initiation. The main secondary endpoint is the occurrence of clinically relevant cerebral infarction at Day 16 post-study drug initiation. Other secondary endpoints include the modified Rankin Scale (mRS) and the Glasgow Outcome Scale-Extended (GOSE) score at Week 12 post-aSAH, dichotomized into poor and good outcome. Radiological results and clinical endpoints are centrally evaluated by independent committees, blinded to treatment allocation. Exploratory efficacy endpoints comprise the assessment of cognition status at 12 weeks and quality of life at 12 and 24 weeks post aSAH.

DISCUSSION

In the REACT study, clazosentan is evaluated on top of standard of care to determine if it reduces the risk of clinical deterioration due to DCI after aSAH. The selection of patients with thick and diffuse clots is intended to assess the benefit/risk profile of clazosentan in a population at high risk of vasospasm-related ischemic complications post-aSAH. TRIAL REGISTRATION (ADDITIONAL FILE 1): ClinicalTrials.gov (NCT03585270). EU Clinical Trial Register (EudraCT Number: 2018-000241-39).

Bispectral index monitoring to detect delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

PURPOSE

Evaluate the bispectral index (BIS) monitoring to detect delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH).

MATERIALS AND METHODS

A single-center prospective study in patients with aSAH. BIS monitoring was recorded during 25-120 min in two periods, within the initial 72 h (BIS1) and between days 4 and 6 (BIS2) from admission. The median for each exported BIS parameter was analyzed. Transcranial Doppler (TCD) sonography was simultaneously performed with BIS1 (TCD1) and BIS2 (TCD2) monitoring. A multivariate logistic regression model was built to identify the variables associated with DCI.

RESULTS

Sixty-four patients were included and 16 (25%) developed DCI. During BIS2 monitoring, significant differences were found in BIS value (left, p = 0.01; right, p = 0.009), 95% spectral edge frequency (left and right, p = 0.04), and total power (left and right, p = 0.04). In multivariable analysis, vasospasm on TCD2 (OR 42.8 [95% CI 3.1-573]; p = 0.005), a median BIS2 value <85 in one or both sides (OR 6.2 [95% CI 1.28-30]; p = 0.023), and age (OR 1.08 [95% CI 1.00-1.17]; p = 0.04) were associated with the development of DCI.

CONCLUSIONS

BIS value is the most useful BIS parameter for detecting DCI after aSAH. Pending further validation, BIS monitoring might be even more accurate than TCD.

Blood pressure and the risk of rebleeding and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

INTRODUCTION AND OBJECTIVE

Blood pressure is presumably related to rebleeding and delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (aSAH) and could serve as a target to improve outcome. We assessed the associations between blood pressure and rebleeding or DCI in aSAH-patients.

MATERIALS AND METHODS

In this observational study in 1167 aSAH-patients admitted to the intensive care unit (ICU), adjusted hazard ratio's (aHR) were calculated for the time-dependent association of blood pressure and rebleeding or DCI. The aHRs were presented graphically, relative to a reference mean arterial pressure (MAP) of 100 mmHg and systolic blood pressure (sBP) of 150 mmHg.

RESULTS

A MAP below 100 mmHg in the 6, 3 and 1 h before each moment in time was associated with a decreased risk of rebleeding (e.g. within 6 h preceding rebleeding: MAP = 80 mmHg: aHR 0.30 (95% confidence interval (CI) 0.11-0.80)). A MAP below 60 mmHg in the 24 h before each moment in time was associated with an increased risk of DCI (e.g. MAP = 50 mmHg: aHR 2.59 (95% CI 1.12-5.96)).

CONCLUSIONS

Our results suggest that a MAP below 100 mmHg is associated with decreased risk of rebleeding, and a MAP below 60 mmHg with increased risk of DCI.

Comparative Study of Vasodilatation After Intra-arterial Nicardipine or Dantrolene Infusion in Animal Model of Cerebral Vasospasm

PURPOSE

Intra-arterial (IA) infusion of calcium channel blockers (CCBs) has been widely applied in treating medically refractory vasospasm; however, surprisingly little is known regarding their vasodilatory duration. This study was undertaken to compare attributes of nicardipine and dantrolene, focusing on efficacy and capacity for sustained vasodilation.

METHODS

In New Zealand white rabbits (N = 22), vasospasm was individually provoked through experimentally induced subarachnoid hemorrhage and confirmed via conventional angiography, grouping animals by IA-infused drug (nicardipine vs. dantrolene). Controls received normal saline. After chemoangioplasty, follow-up angiography was performed at intervals of 1-3 h for 6 h to compare vasospastic and dilated (i.e., treated) arterial diameters. Drug efficacy, duration of action, and changes in mean arterial pressure (relative to baseline) were analyzed by group.

RESULTS

Compared with controls, effective vasodilation was evident in both nicardipine and dantrolene test groups after IA infusion. Vasodilatory effects of nicardipine peaked at 1 h, returning to former vasospastic states at 3 h. In dantrolene recipients, vasodilation endured longer, lasting >6 h. Only the nicardipine group showed a significant 3‑h period of lowered blood pressure.

CONCLUSION

Unlike the vasodilatory action of a CCB, sustained for < 3 h after IA infusion, the effect of dantrolene endured for > 6 h. This outcome suggests that IA dantrolene infused alone or together with a conventional CCB infusion may be a new means of prolonging vasodilatory effect. Further research is needed to assess durations of IA-infused vasodilatory drug based on perfusion status.

Emergent Subarachnoid Clot Removal with Aneurysm Repair for Subarachnoid Hemorrhage Might Improves Clinical Outcome

BACKGROUND

The goal in treating patients with subarachnoid hemorrhage (SAH) is shifting to preventing early brain injury. Intracranial pressure must be controlled to manage such an injury. We retrospectively analyzed the impact of aggressive removal of cisternal subarachnoid clots with simultaneous aneurysm repair for all grades of SAH.

METHODS

Our study included 260 consecutive patients with SAH treated through aggressive subarachnoid clot removal with simultaneous aneurysm repair. Baseline patient characteristics, history, radiographic findings, and time of SAH onset to arrival in the operating room were retrospectively collected. Factors related to poor outcome (modified Rankin Scale score >2) were analyzed.

RESULTS

Multivariate analysis revealed several characteristics were significantly associated with poor outcome: advanced age (adjusted odds ratio [aOR] 1.07, 95% confidence interval [CI] 1.04-01.10); time of SAH onset to operating room per 1-hour increments (aOR 1.03, 95% CI 1.01-01.05; postoperative hematoma volume (aOR 1.04, 95% CI 1.01-01.06); and poorer World Federation of Neurosurgical Societies grade (aOR 2.18, 95% CI 1.63-02.92). According to a receiver operating characteristic analysis, the cut-off time of SAH onset to operating room was 6.0 hours (area under the curve 0.61, P = 0.01, 95% CI 0.52-0.69, sensitivity = 0.79, specificity = 0.43) as the threshold between modified Rankin Scale scores of 0-2 and 3-6.

CONCLUSIONS

Prognostic factors of SAH in patients undergoing emergent aneurysm repair with simultaneous removal of a cisternal subarachnoid clot are advanced age, poorer World Federation of Neurosurgical Societies grade, postoperative hematoma volume, and a longer time from SAH onset to operating room. The clinical outcome may improve with emergent reduction of intracranial pressure through removal of the subarachnoid clot as soon as possible.

Automated EEG-based prediction of delayed cerebral ischemia after subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral ischemia (DCI) is a leading complication of aneurysmal subarachnoid hemorrhage (SAH) and electroencephalography (EEG) is increasingly used to evaluate DCI risk. Our goal is to develop an automated DCI prediction algorithm integrating multiple EEG features over time.

METHODS

We assess 113 moderate to severe grade SAH patients to develop a machine learning model that predicts DCI risk using multiple EEG features.

RESULTS

Multiple EEG features discriminate between DCI and non-DCI patients when aligned either to SAH time or to DCI onset. DCI and non-DCI patients have significant differences in alpha-delta ratio (0.08 vs 0.05, p < 0.05) and percent alpha variability (0.06 vs 0.04, p < 0.05), Shannon entropy (p < 0.05) and epileptiform discharge burden (205 vs 91 discharges per hour, p < 0.05) based on whole brain and vascular territory averaging. Our model improves predictions by emphasizing the most informative features at a given time with an area under the receiver-operator curve of 0.73, by day 5 after SAH and good calibration between 48-72 hours (calibration error 0.13).

CONCLUSIONS

Our proposed model obtains good performance in DCI prediction.

SIGNIFICANCE

We leverage machine learning to enable rapid, automated, multi-featured EEG assessment and has the potential to increase the utility of EEG for DCI prediction.

Health Care Expenditures Associated with Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage: A Propensity-Adjusted Analysis

OBJECTIVE

The additional hospital costs associated with delayed cerebral ischemia (DCI) have not been well investigated in prior literature. In this study, the total hospital cost of DCI in aneurysmal subarachnoid hemmorhage (aSAH) patients treated at a single quaternary center was analyzed.

METHODS

All patients in the Post-Barrow Ruptured Aneurysm Trial treated for an aSAH between January 1, 2014, and July 31, 2019, were retrospectively analyzed. DCI was defined as cerebral infarction identified on computed tomography, magnetic resonance imaging, or autopsy after exclusion of procedure-related infarctions. The primary outcome was the difference in total cost (including hospital, discharge facility, and all follow-up) using a propensity-adjusted analysis. Propensity score covariate-adjusted linear regression analysis included age, sex, open versus endovascular treatment, Hunt and Hess score, and Charlson Comorbidity Index score.

RESULTS

Of the 391 patients included, 144 (37%) had DCI. Patients with DCI had a significantly greater cost compared to patients without DCI (mean standard deviation $112,081 [$54,022] vs. $86,159 [$38,817]; P < 0.001) and a significantly greater length of stay (21 days [11] vs. 18 days [8], P = 0.003, respectively). In propensity-adjusted linear regression analysis, both DCI (odds ratio, $13,871; 95% confidence interval, $7558-$20,185; P < 0.001) and length of stay (odds ratio, $3815 per day; 95% confidence interval, $3480-$4149 per day; P < 0.001) were found to significantly increase the cost.

CONCLUSIONS

The significantly higher costs associated with DCI further support the evidence that adverse effects associated with DCI in aSAH pose a significant burden to the health care system.

Angiographic Treatment of Asymptomatic Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage for the Prevention of Delayed Cerebral Ischemia

OBJECTIVE

Angiographic treatment of asymptomatic cerebral vasospasm (CVS) in aneurysmal subarachnoid hemorrhage remains controversial. We sought to investigate its relationship with the development of delayed cerebral ischemia.

METHODS

Consecutive patients admitted between July 2017 and June 2019, with a diagnosis of aneurysmal subarachnoid hemorrhage, were retrospectively analyzed. The rate of development of delayed cerebral ischemia was compared between a group of patients who underwent cerebral angiography for asymptomatic CVS and those who did not. The Mann-Whitney U test or χ² test was used to compare the 2 groups.

RESULTS

Thirty-seven of the 94 patients with aneurysmal subarachnoid hemorrhage were screened for CVS, of whom 16 (43%) had moderate-severe vasospasm. When patients who underwent therapeutic cerebral angiography were compared with those who did not and after adjusting for sex, age, and grade of subarachnoid hemorrhage, treatment was not found to be significantly associated with delayed cerebral ischemia (hazard ratio = 0.82, 95% confidence interval: 0.19-3.52, P = 0.79). We found that the median length of stay in the intensive care unit and hospital increased significantly with the severity of CVS (P < 0.001).

CONCLUSIONS

Cerebral angiography has a low rate of detecting moderate-severe CVS in asymptomatic patients. Moreover, there was no statistically significant difference in the rate of delayed cerebral ischemia between asymptomatic patients treated versus those not treated for CVS. There was significant association between the severity of CVS and the intensive care unit and hospital length of stay. More studies are needed to evaluate the utility of treating asymptomatic CVS in high-grade aneurysmal subarachnoid hemorrhage.

Targeting Hemoglobin to Reduce Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) continues to be a sequela of aneurysmal subarachnoid hemorrhage (aSAH) that carries significant morbidity and mortality. Aside from nimodipine, no therapeutic agents are available to reduce the incidence of DCI. Pathophysiologic mechanisms contributing to DCI are poorly understood, but accumulating evidence over the years implicates several factors. Those have included microvessel vasoconstriction, microthrombosis, oxidative tissue damage, and cortical spreading depolarization as well as large vessel vasospasm. Common to these processes is red blood cell leakage into the cerebrospinal fluids (CSF) and subsequent lysis which releases hemoglobin, a central instigator in these events. This has led to the hypothesis that early blood removal may improve clinical outcome and reduce DCI. This paper will provide a narrative review of the evidence of hemoglobin as an instigator of DCI. It will also elaborate on available human data that discuss blood clearance and CSF drainage as a treatment of DCI. Finally, we will address a recent novel device that is currently being tested, the Neurapheresis CSF Management System™. This is an automated dual-lumen lumbar drainage system that has an option to filter CSF and return it to the patient.

Serum concentrations of NLRP3 in relation to functional outcome and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) participates in neuroinflammation. We endeavored to determine the role of serum NLRP3 as a biomarker of neuroinflammation, severity, delayed cerebral ischemia (DCI) and functional outcome following aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

In this prospective and observational study, a total of 118 aSAH patients and 118 healthy volunteers were enrolled. Serum NLRP3 concentrations, blood glucose concentrations, serum C-reactive protein concentrations, and blood leucocyte counts were quantified. A poor outcome was defined as extended Glasgow outcome scale scores of 1-4 at post-injury 90 days.

RESULTS

As compared to controls, significantly increased serum NLRP3 concentrations after aSAH were intimately correlated with the Glasgow coma scale scores, World Federation of Neurological Surgeons scale scores, Hunt-Hess scores, modified Fisher scores, extended Glasgow outcome scale scores, blood glucose concentrations, serum C-reactive protein concentrations and blood leucocyte counts. Serum NLRP3 emerged as an independent predictor for DCI and poor 90-day outcome. Using receiver operating characteristic curve, serum NLRP3 concentrations were significantly predictive of DCI and poor 90-day outcome. Its prognostic predictive ability was comparable to those of the Glasgow coma scale scores, World Federation of Neurological Surgeons scale scores, Hunt-Hess scores and modified Fisher scores.

CONCLUSIONS

Serum NLRP3 may represent an inflammatory biomarker in relation to the severity, DCI and poor functional outcome after aSAH.

High epileptiform discharge burden predicts delayed cerebral ischemia after subarachnoid hemorrhage

OBJECTIVE

To investigate whether epileptiform discharge burden can identify those at risk for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH).

METHODS

Retrospective analysis of 113 moderate to severe grade SAH patients who had continuous EEG (cEEG) recordings during their hospitalization. We calculated the burden of epileptiform discharges (ED), measured as number of ED per hour.

RESULTS

We find that many SAH patients have an increase in ED burden during the first 3-10 days following rupture, the major risk period for DCI. However, those who develop DCI have a significantly higher hourly burden from days 3.5-6 after SAH vs. those who do not. ED burden is higher in DCI patients when assessed in relation to the onset of DCI (area under the receiver operator curve 0.72). Finally, specific trends of ED burden over time, assessed by group-based trajectory analysis, also help stratify DCI risk.

CONCLUSIONS

These results suggest that ED burden is a useful parameter for identifying those at higher risk of developing DCI after SAH. The higher burden rate associated with DCI supports the theory of metabolic supply-demand mismatch which contributes to this complication.

SIGNIFICANCE

ED burden is a novel biomarker for predicting those at high risk of DCI.

Clinical Outcome and Prognostic Factors of Patients with Perimesencephalic and Nonperimesencephalic Subarachnoid Hemorrhage

OBJECTIVE

To demonstrate the clinical outcome of patients with nonperimesencephalic subarachnoid hemorrhage (npSAH) compared with patients with aneurysmal SAH (aSAH) and perimesencephalic SAH (pSAH) and to evaluate predictive value of various clinical and radiological findings in patients with npSAH.

METHODS

We retrospectively identified patients with SAH who presented at our institution between 2009 and 2018. We analyzed demographic and clinical data and outcomes. Multivariable analysis was performed for outcome parameters.

RESULTS

Of 608 patients with confirmed SAH, 78% had aSAH, and 22% had nonaneurysmal SAH. Nonaneurysmal SAH was perimesencephalic in 30% of cases and nonperimesencephalic in 70%. Initial clinical status (Hunt and Hess score) was significantly worse in patients with aSAH compared with patients with nonaneurysmal SAH. Complications such as delayed cerebral ischemia occurred significantly more often in patients with aSAH. Patients with pSAH had a more favorable clinical course than patients with aSAH or npSAH. There was no significant difference in 30-day mortality between aSAH (29%) and npSAH (28%) patients (P = 0.835). Hunt and Hess score emerged as a strong predictor of unfavorable outcome in both aSAH and npSAH in multivariable regression.

CONCLUSIONS

Patients with npSAH had a similar clinical outcome as patients with aSAH, although there were significantly fewer clinical complications in patients with npSAH. Patients with pSAH demonstrated an overall good clinical course. Our multivariable analysis showed that initial Hunt and Hess score was an important predictor for clinical outcome in aSAH as well as npSAH.

Slow recruitment in the HIMALAIA study: lessons for future clinical trials in patients with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on feasibility data

Background

Our randomized clinical trial on induced hypertension in patients with delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) was halted prematurely due to unexpected slow recruitment rates. This raised new questions regarding recruitment feasibility. As our trial can therefore be seen as a feasibility trial, we assessed the reasons for the slow recruitment, aiming to facilitate the design of future randomized trials in aSAH patients with DCI or other critically ill patient categories.

Methods

Efficiency of recruitment and factors influencing recruitment were evaluated, based on the patient flow in the two centers that admitted most patients during the study period. We collected numbers of patients who were screened for eligibility, provided informed consent, and developed DCI and who eventually were randomized.

Results

Of the 862 aSAH patients admitted in the two centers during the course of the trial, 479 (56%) were eligible for trial participation of whom 404 (84%) were asked for informed consent. Of these, 188 (47%) provided informed consent, of whom 50 (27%) developed DCI. Of these 50 patients, 12 (24%) could not be randomized due to a logistic problem or a contraindication for induced hypertension emerging at the time of randomization, and four (8%) were missed for randomization. Eventually, 34 patients were randomized and received intervention or control treatment.

Conclusions

Enrolling patients in a randomized trial on a treatment strategy for DCI proved unfeasible: only 1 out of 25 admitted and 1 out of 14 eligible patients could eventually be randomized. These rates, caused by a large proportion of ineligible patients, a small proportion of patients providing informed consent, and a large proportion of patients with contraindications for treatment, can be used to make sample size calculations for future randomized trials in DCI or otherwise critically ill patients. Facilitating informed consent through improved provision of information on risks, possible benefits, and study procedures may result in improved enrolment.

Trial registration

The original trial was prospectively registered with ClinicalTrials.gov (NCT01613235), date of registration 07-06-2012.

Microglia and Post-Subarachnoid Hemorrhage Vasospasm: Review of Emerging Mechanisms and Treatment Modalities

Vasospasm is a potentially severe complication of subarachnoid hemorrhage. It can be attributed to neuroinflammation and the robust recruitment of microglia. Emerging evidence has linked this sustained inflammation to the development of delayed cerebral ischemia following subarachnoid hemorrhage. In this focused review, we provide an overview of the historical understanding of vasospasm. We then delve into the role of neuroinflammation and the activation of microglia. These activated microglia releases a host of inflammatory cytokines contributing to an influx of peripheral macrophages. This thereby opens a new and innovative treatment strategy to prevent vasospasm. Pre-clinical work has been promising, and the transition to clinical trials is warranted. Finally, some of the key mechanistic targets are outlined with emphasis on translation. This review will serve as a catalyst for researchers and clinicians alike in the quest to improve treatment options for vasospasm.

The value of early CT perfusion parameters for predicting delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Delayed cerebral ischemia (DCI) is a devastating complication of aneurysmal subarachnoid hemorrhage (aSAH). We aim to investigate the efficacy of early CT perfusion (CTP) parameters for predicting DCI in patients with aSAH. The search was conducted in five databases (PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and China Biology Medicine database). Studies were reviewed by two independent authors, and the included studies were assessed for methodological quality. Fifteen studies with 882 participants were included for the final analysis. The meta-analysis of quantitative parameters showed that mean transit time represented the most valuable predictor when the calculation of the mean value was uniformed (MD 0.30 s, 95% CI: 0.10 to 0.49 s, P = 0.003). Semi-quantitative parameters using relative values or index scores were also widely used to minimize undue variations derived from patients, operators, machines, and software. Studies also demonstrated that these relative parameters had better predictive accuracy than corresponding absolute parameters. Perfusion thresholds in each study were incomparable, and the results warranted further validation. The best threshold for the prediction was 0.9 using the relative cerebral blood flow parameter (sensitivity 97% and specificity 89%). We conclude that CTP in the early phase is a promising tool for predicting DCI in aSAH patients. However, the parameters require standardization. Future studies with prospective, multi-centered design and large sample size are needed to validate the thresholds and optimize the parameters.

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

Introduction

Preclinical studies provided a strong rationale for a pathophysiological link between cell-free hemoglobin in the cerebrospinal fluid (CSF-Hb) and secondary brain injury after subarachnoid hemorrhage (SAH-SBI). In a single-center prospective observational clinical study, external ventricular drain (EVD) based CSF-Hb proved to be a promising biomarker to monitor for SAH-SBI. The primary objective of the HeMoVal study is to prospectively validate the association between EVD based CSF-Hb and SAH-SBI during the first 14 days post-SAH. Secondary objectives include the assessment of the discrimination ability of EVD based CSF-Hb for SAH-SBI and the definition of a clinically relevant range of EVD based CSF-Hb toxicity. In addition, lumbar drain (LD) based CSF-Hb will be assessed for its association with and discrimination ability for SAH-SBI.

Methods

HeMoVal is a prospective international multicenter observational cohort study. Adult patients admitted with aneurysmal subarachnoid hemorrhage (aSAH) are eligible. While all patients with aSAH are included, we target a sample size of 250 patients with EVD within the first 14 day after aSAH. Epidemiologic and disease-specific baseline measures are assessed at the time of study inclusion. In patients with EVD or LD, each day during the first 14 days post-SAH, 2 ml of CSF will be sampled in the morning, followed by assessment of the patients for SAH-SBI, co-interventions, and complications in the afternoon. After 3 months, a clinical follow-up will be performed. For statistical analysis, the cohort will be stratified into an EVD, LD and full cohort. The primary analysis will quantify the strength of association between EVD based CSF-Hb and SAH-SBI in the EVD cohort based on a generalized additive model. Secondary analyses include the strength of association between LD based CSF-Hb and SAH-SBI in the LD cohort based on a generalized additive model, as well as the discrimination ability of CSF-Hb for SAH-SBI based on receiver operating characteristic (ROC) analyses.

Discussion

We hypothesize that this study will validate the value of CSF-Hb as a biomarker to monitor for SAH-SBI. In addition, the results of this study will provide the potential base to define an intervention threshold for future studies targeting CSF-Hb toxicity after aSAH.

Study registration

ClinicalTrials.gov Identifier NCT04998370. Date of registration: August 10, 2021.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Delayed ischemic neurologic deficit with vasospasm in aneurysmal subarachnoid hemorrhage after negative post-bleed day 7 angiography

OBJECTIVE

Routine post-bleed day 7 (PBD7) angiography has been utilized to evaluate for vasospasm in aneurysmal subarachnoid hemorrhage (SAH). We sought to assess the rate of delayed-cerebral ischemia (DCI) associated with angiographic vasospasm following negative PBD7 angiography.

METHODS

Retrospective review of 178 aneurysmal SAH patients was performed. Patients underwent routine angiography on or around 7 days after hemorrhage. Primary variables assessed were the rate of vasospasm detection on PBD7 angiograms and rate of subsequent development of delayed-cerebral ischemia (DCI) associated with angiographic vasospasm in patients without spasm on PBD7. Statistical analysis was carried out for contributing factors.

RESULTS

Eighty-four of 178 patients (47.2 %) developed angiographically proven vasospasm during their hospital course. Seven patients (3.9 %) were clinically suspected to have vasospasm prior to PBD7 with radiographic confirmation. Sixty-nine patients (38.8%) demonstrated novel spasm on routine PBD7 angiogram, with 56.5 % of these patients showing vasospasm on angiography obtained after PBD7 for DCI. One hundred and two patients (57.3 %) had no vasospasm on routine PBD7 angiography. Eight patients in the PBD7 spasm-free subgroup went on to develop DCI with angiographic spasm. These 8 patients represent 4.5 % (8/178) of all patients, 7.8 % (8/102) of the PBD7 negative subgroup, and 9.5 % (8/84) of patients with angiographic spasm during admission.

CONCLUSION

The majority of patients (90.4 %) with angiographic vasospasm manifested on or before PBD7. DCI with angiographically-proven spasm arouse infrequently (7.8 %) after negative PBD7 angiography. Further study of PBD7 angiography may help determine which SAH patients in whom shortened length-of-stay might safely be pursued.

Dynamic Measurements of Cerebral Blood Flow Responses to Cortical Spreading Depolarization in the Murine Endovascular Perforation Subarachnoid Hemorrhage Model

Delayed cerebral ischemia (DCI) is the most severe complication after subarachnoid hemorrhage (SAH), and cortical spreading depolarization (CSD) is believed to play a vital role in it. However, the dynamic changes in cerebral blood flow (CBF) in response to CSD in typical SAH models have not been well investigated. Here, SAH was established in mice with endovascular perforation. Subsequently, the spontaneous CBF dropped instantly and then returned to baseline rapidly. After KCl application to the cortex, subsequent hypoperfusion waves occurred across the groups, while a lower average perfusion level was found in the SAH groups (days 1-7). Moreover, in the SAH groups, the number of CSD decreased within day 7, and the duration and spreading velocity of the CSD increased within day 3 and day 14, respectively. Next, we continuously monitored the local field potential (LFP) in the prefrontal cortex. The results showed that the decrease in the percentage of gamma oscillations lasted throughout the whole process in the SAH group. In the chronic phase after SAH, we found that the mice still had cognitive deficits but experienced no obvious tissue damage. In summary, SAH negatively affects the CBF responses to CSD and the spontaneous LFP activity and causes long-term cognitive deficits in mice. Based on these findings, in the specific phase after SAH, DCI is induced or exacerbated more easily by potential causers of CSD in clinical practice (edema, erythrocytolysis, inflammation), which may lead to neurological deterioration.

Serum Gas6 contributes to clinical outcome after aneurysmal subarachnoid hemorrhage: A prospective cohort study

BACKGROUND

Growth-arrest-specific protein 6 (Gas6) exerts nervous protective effects on acute brain injury. We endeavored to ascertain whether serum Gas6 concentrations are associated with severity, delayed cerebral ischemia (DCI) and prognosis following aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

We measured serum Gas6 concentrations of 124 aSAH patients. The Hunt-Hess scale and modified Fisher grading scale were used to evaluate illness severity. Multivariate analysis was utilized to determine relationships between serum Gas6 concentrations and severity, DCI plus 90-day unfavorable outcome (Glasgow outcome scale score of 1-3).

RESULTS

Patients with unfavorable outcome or DCI had significantly higher serum Gas6 concentrations than other remainders (median, 35.0 vs 23.3 ng/ml; 36.1 vs 25.3 ng/ml; both P < 0.001). Serum Gas6 concentrations displayed independent correlations with Hunt-Hess scores (t = 5.518, P < 0.001) and modified Fisher scores (t = 3.531, P = 0.001). Serum Gas6 concentrations were independently associated with unfavorable outcome (OR: 1.125; 95% CI, 1.063-1.190; P = 0.014) and DCI (OR: 1.104; 95% CI, 1.041-1.170; P = 0.010) as well as exhibited AUCs of 0.786 (95% CI, 0.703-0.854) and 0.753 (95% CI, 0.668-0.826) for predicting unfavorable outcome and DCI respectively. Its discriminatory ability for risk of unfavorable outcome or DCI was similar to those of Hunt-Hess scores and modified Fisher scores (all P > 0.05).

CONCLUSIONS

Serum Gas6 concentrations are independently associated with stroke severity and worse clinical outcome after aSAH, indicating serum Gas6 may be a potential prognostic biomarker for aSAH.

Cortical Spreading Depolarizations and Clinically Measured Scalp EEG Activity After Aneurysmal Subarachnoid Hemorrhage and Traumatic Brain Injury

BACKGROUND

Spreading depolarizations (SDs) are associated with worse outcome following subarachnoid hemorrhage (SAH) and traumatic brain injury (TBI), but gold standard detection requires electrocorticography with a subdural strip electrode. Electroencephalography (EEG) ictal-interictal continuum abnormalities are associated with poor outcomes after TBI and with both delayed cerebral ischemia (DCI) and poor outcomes after SAH. We examined rates of SD detection in patients with SAH and TBI with intraparenchymal and subdural strip electrodes and assessed which continuous EEG (cEEG) measures were associated with intracranially quantified SDs.

METHODS

In this single-center cohort, we included patients with SAH and TBI undergoing ≥ 24 h of interpretable intracranial monitoring via eight-contact intraparenchymal or six-contact subdural strip platinum electrodes or both. SDs were rated according to established consensus criteria and compared with cEEG findings rated according to the American Clinical Neurophysiology Society critical care EEG monitoring consensus criteria: lateralized rhythmic delta activity, generalized rhythmic delta activity, lateralized periodic discharges, generalized periodic discharges, any ictal-interictal continuum, or a composite scalp EEG tool for seizure risk estimation: the 2HELPS2B score. Among patients with SAH, cEEG was assessed for validated DCI biomarkers: new or worsening epileptiform abnormalities and new background deterioration.

RESULTS

Over 6 years, SDs were recorded in 5 (18%) of 28 patients recorded with intraparenchymal electrodes and 4 (40%) of 10 patients recorded with subdural strip electrodes. There was no significant association between occurrence of SDs and day 1 cEEG findings (American Clinical Neurophysiology Society main terms lateralized periodic discharges, generalized periodic discharges, lateralized rhythmic delta activity, or seizures, individually or in combination). After SAH, established cEEG DCI predictors were not associated with SDs.

CONCLUSIONS

Intraparenchymal recordings yielded low rates of SD, and documented SDs were not associated with ictal-interictal continuum abnormalities or other cEEG DCI predictors. Identifying scalp EEG correlates of SD may require training computational EEG analytics and use of gold standard subdural strip electrocorticography recordings.

C-reactive protein elevation predicts in-hospital deterioration after aneurysmal subarachnoid hemorrhage: a retrospective observational study

Background

There is increasing evidence that inflammation plays a role in the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH) and in the development of delayed cerebral ischemia (DCI). However, the assessment and interpretation of classically defined inflammatory parameters is difficult in aSAH patients. The objective of this study was to investigate the relationship between easily assessable findings (hyperventilation, fever, white blood cell count (WBC), and C-reactive protein (CRP)) and the occurrence of DCI and unfavorable neurological outcome at discharge in aSAH patients.

Methods

Retrospective analysis of prospectively collected data from a single center cohort. We evaluated the potential of clinical signs of inflammation (hyperventilation, fever) and simple inflammatory laboratory parameters CRP and WBC to predict unfavorable outcomes at discharge and DCI in a multivariate analysis. A cutoff value for CRP was calculated by Youden’s J statistic. Outcome was measured using the modified Rankin score at discharge, with an unfavorable outcome defined as modified Rankin scale (mRS) > 3.

Results

We included 97 consecutive aSAH patients (63 females, 34 males, mean age 58 years) in the analysis. Twenty-one (22%) had major disability or died by the time of hospital discharge. Among inflammatory parameters, CRP over 100 mg/dl on day 2 was an independent predictor for worse neurological outcome at discharge. The average C-reactive protein level in the first 14 days was higher in patients with a worse neurological outcome (96.6, SD 48.3 vs 56.3 mg/dl, SD 28.6) in the first 14 days after aSAH. C-reactive protein on day 2 was an indicator of worse neurological outcome. No inflammatory parameter was an independent predictor of DCI. After multivariate adjustment, DCI, increased age, and more than 1 day of mechanical ventilation were significant predictors of worse neurological outcome.

Conclusions

Early elevated CRP levels were a significant predictor of worse neurological outcome at hospital discharge and may be a useful marker of later deterioration in aSAH.

Decompressive hemicraniectomy after aneurysmal subarachnoid hemorrhage-justifiable in light of long-term outcome?

Purpose

Decompressive hemicraniectomy (DHC) is a potentially lifesaving procedure in refractory intracranial hypertension, which can prevent death from brainstem herniation but may cause survival in a disabled state. The spectrum of indications is expanding, and we present long-term results in a series of patients suffering from aneurysmal subarachnoid hemorrhage (SAH).

Methods

We performed a retrospective analysis of previously registered data including all patients treated for SAH between 2010 and 2018 in a single institution. Patients treated with decompressive hemicraniectomy due to refractory intracranial hypertension were identified. Clinical outcome was assessed by means of the Glasgow outcome scale after 12 months.

Results

Of all 341 SAH cases, a total of 82 (24.0%) developed intracranial hypertension. Of those, 63 (18.5%) patients progressed into refractory ICP elevation and were treated with DHC. Younger age (OR 0.959, 95% CI 0.933 to 0.984; p = 0.002), anterior aneurysm location (OR 0.253, 95% CI 0.080 to 0.799; 0.019; p = 0.019), larger aneurysm size (OR 1.106, 95% CI 1.025 to 1.194; p = 0.010), and higher Hunt and Hess grading (OR 1.944, 95% CI 1.431 to 2.641; p < 0.001) were independently associated with the need for DHC. After 1 year, 10 (15.9%) patients after DHC were categorized as favorable outcome. Only younger age was independently associated with favorable outcome (OR 0.968 95% CI 0.951 to 0.986; p = 0.001).

Conclusions

Decompressive hemicraniectomy, though lifesaving, has only a limited probability of survival in a clinically favorable condition. We identified young age to be the sole independent predictor of favorable outcome after DHC in SAH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05250-6.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital with neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)-part 2

BACKGROUND

Questions remain on the optimal management of subarachnoid hemorrhage (SAH) patients once they are admitted to the referring center, before and after the aneurysm treatment. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI) to provide clinical guidance regarding this topic. Specifically, in this manuscript (part 2), we aim to provide a list of experts' recommendations regarding the management of SAH patients in a center with neurosurgical/neuroendovascular facilities after aneurysm treatment.

METHODS

A multidisciplinary consensus panel composed by 24 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different specializations (anesthesia/intensive care, neurosurgery, and interventional neuroradiology) was created. A modified Delphi approach was adopted.

RESULTS

A total of 33 statements were discussed, voted, and approved. Consensus was reached on 30 recommendations (28 strong and 2 weak). In 3 cases, where consensus could not be agreed upon, no recommendation was provided.

CONCLUSIONS

This consensus provides practical recommendations (and not mandatory standard of practice) to support clinician's decision-making in the management of SAH patients in centers with neurosurgical/neuroendovascular facilities after aneurysm securing.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Economic and Humanistic Burden of Cerebral Vasospasm and Its Related Complications after Aneurysmal Subarachnoid Hemorrhage: A Systematic Literature Review

Introduction

Cerebral vasospasm (VSP) is the leading risk factor of neurological deterioration (i.e., delayed cerebral ischemia [DCI] and cerebral infarction) after aneurysmal subarachnoid hemorrhage (aSAH) and a cause of morbidity and mortality. The objective of this systematic literature review is to summarize the economic and humanistic burden of VSP and its related complications after aSAH.

Methods

A predefined protocol was designed, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Systematic searches were conducted in MEDLINE, Embase, and Cochrane (in January 2021) to identify studies reporting economic and/or humanistic (i.e., health-related quality of life [HRQoL]) outcomes for patients with asymptomatic and symptomatic VSP after aSAH. Related conferences and additional sources were searched manually. Dual screening, data extraction, and qualitative analysis were conducted.

Results

Of 3818 abstracts identified for review, 43 full-text articles representing 42 single studies met the inclusion criteria and were included. Most studies (33) were observational; nine were randomized clinical trials (RCTs). Economic outcomes were reported in 31 studies, and alongside HRQoL outcomes in 4 studies; 7 studies reported HRQoL outcomes only. Forty studies were conducted in single countries, while only 2 RCTs were conducted in multiple countries. Patients diagnosed with VSP or DCI spent between 2.1 and 7.4 days longer in intensive care and between 4.7 and 17 days longer in hospital (total) compared with patients without VSP or DCI. A significantly higher cost burden of US$33,945 (2021 £26,712) was identified for patients with VSP and £9370 (2021 £13,733) for patients with DCI compared with patients without. Patients with DCI were also disadvantaged by being employed for 62 fewer days (during 24-month follow-up), with an estimated mean cost of £3821 (2021 £5600) for days off work. Poor HRQoL was associated with ≥ 1 days with VSP symptoms (odds ratio [OR]: 2.8, 95% confidence interval [CI]: 1.4–5.3), symptomatic VSP (OR: 1.9, 95% CI: 1.0–3.6), and DCI (OR: 2.3, 95% CI: 1.3–4.2), although this was not consistent across all studies. Symptomatic VSP and DCI were identified as significant risk factors for depressed mood (OR: 2.2, 95% CI: 1.0–4.9) and global cognitive impairment (OR: 2.3) at 12 months, respectively. The severity of VSP was a critical predictor of post-aSAH economic and humanistic burden. Similar trends in economic and humanistic burden were identified in the general aSAH patient population. Study design and patient heterogeneity precluded direct metaanalysis of the results.

Conclusion

A substantial direct and indirect economic burden is linked to VSP and its related complications after aSAH. Although limited evidence was identified for humanistic burden, these patients seem to suffer from poor HRQoL with long-lasting burden. Overall, there is an urgent need to understand better the concept of “burden of illness” of VSP and its related complications after aSAH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00348-6.

Aneurysmal subarachnoid hemorrhage is a sudden, life-threatening emergency caused by bleeding in the subarachnoid space between the brain and skull. Vasospasm of the arteries surrounding the hemorrhage occurs in most patients and may lead to permanent brain damage. This study summarizes the published literature to describe the burden that patients may experience due to vasospasm and its related complications after aneurysmal subarachnoid hemorrhage, focusing on financial and life quality aspects. We show that the burden of vasospasm, and its related complications, is huge. Patients often experience reduced quality of life due to their poor health and are more likely to suffer from depression and intellectual impairment. There is also a substantial financial burden linked to vasospasm and its related complications, driven by the need for more intensive care, hospitalization, and higher investigative costs associated with the treatment and management of these patients. In addition, days off work and unemployment can cause a substantial indirect financial burden. Our study highlights the need for additional research to understand further the “burden of illness” of vasospasm and its related complications after aneurysmal subarachnoid hemorrhage.

Large practice variations in diagnosis and treatment of delayed cerebral ischemia after subarachnoid hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) contributes to poor outcomes after subarachnoid hemorrhage (SAH). The pathophysiology of DCI is not fully understood, which has hindered the adoption of a uniform definition. Furthermore, a reliable diagnostic test and an effective evidence-based treatment are lacking. This could lead to variations in care.

METHODS

A web-based survey on the variations in the definition, diagnosis, and treatment of DCI was designed and sent to 314 intensivists, neurologists, and neurosurgeons of all 9 hospitals in the Netherlands who care for patients with SAH. The responders were categorized into physicians responsible for the coordination of SAH care and those who were not. For questions on the definition and diagnosis, only the responses from the coordinating physicians were evaluated. For the treatment questions, all the responses were evaluated.

RESULTS

The response rate was 34% (106 of 314). All 9 hospitals were represented. Of the responses, 27 did not provide answers for the definition, diagnosis, or treatment questions; 79 responses were used for analysis. Signs of vasospasm were required by 21 of the 47 coordinating physicians (44%) when considering DCI. Of the 47 coordinating physicians, 24 (51%) did not use a diagnostic test results for a positive diagnosis of DCI. When patients were discharged within 21 days, 33 of the 73 responders (45%) did not provide a prescription for nimodipine continuation. Finally, all but one hospital had treated DCI with hypertension induction.

CONCLUSIONS

We found large variations in the definition, diagnosis, and treatment of DCI in the Netherlands. In the absence of evidence-based treatment, standardization of management seems warranted in an effort to optimize DCI care.

Incremental Versus Immediate Induction of Hypertension in the Treatment of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Background

Delayed cerebral ischemia (DCI) is a common complication of aneurysmal subarachnoid hemorrhage and contributes to unfavorable outcome. In patients with deterioration despite prophylactic nimodipine treatment, induced hypertension (iHTN) can be considered, although the safety and efficacy of induction are still a matter of debate. In this study, two iHTN treatment algorithms were compared with different approaches toward setting pressure targets.

Methods

In a cohort of 325 consecutive patients with subarachnoid hemorrhage, 139 patients were treated by induced hypertension as a first tier treatment. On diagnosing DCI, blood pressure was raised via norepinephrine infusion in 20-mm Hg increments in 37 patients (iHTN_incr), whereas 102 patients were treated by immediate elevation to systolic pressure above 180 mm Hg (iHTN_imm). Treatment choice was based on personal preference of the treating physician but with a gradual shift away from incremental elevation. Both groups were evaluated for DCI-caused infarction, the need of additional endovascular rescue treatment, the occurrence of pressor-treatment-related complications, and clinical outcome assessed by the extended Glasgow outcome scale after 12 months.

Results

The rate of refractory DCI requiring additional rescue therapy was comparable in both groups (48.9% in iHTN_incr, 40.0% in iHTN_imm; p = 0.332). The type of induced hypertension was not independently associated with the occurrence of DCI-related infarction in a logistic regression model (odds ratio 1.004; 95% confidence interval 0.329–3.443; p = 0.942). Similar rates of pressor-treatment-related complications were observed in both treatment groups. Favorable outcome was reached in 44 (43.1%) patients in the immediate vs. 10 (27.0%) patients in the incremental treatment group (p = 0.076). However, only Hunt and Hess grading was identified as an independent predictor variable of clinical outcome (odds ratio 0.422; 95% confidence interval 0.216–0.824; p = 0.012).

Conclusions

Immediate induction of hypertension with higher pressure targets did not result in a lower rate of DCI-related infarctions but was not associated with a higher complication rate compared with an incremental approach. Future tailored blood pressure management based on patient- and time-point-specific needs will hopefully better balance the neurological advantages versus the systemic complications of induced hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-022-01466-7.

Higher cystatin C level increases the risk of delayed cerebral ischemia after endovascular treatment of aneurysmal subarachnoid hemorrhage: a case-control study

Cystatin C (CysC) has been found to be associated with hemorrhagic and ischemic stroke in many studies. However, the association between CysC level and the risk of delayed cerebral ischemia after endovascular treatment of aneurysmal subarachnoid hemorrhage has been reported rarely. Our study was proposed to explore this association. Consecutive patients from June 2015 to February 2021 in this single-center retrospective study were selected. Univariate and multivariate analyses were used to identify potential prognostic risk factors for delayed cerebral ischemia, and the stability of the association was demonstrated by several statistical methods, such as subgroup analysis, interaction testing, generalized linear models, and propensity score matching. A total of 424 patients were included in the analysis. Cystatin C was independently associated with delayed cerebral ischemia. The independent effects of CysC on delayed cerebral ischemia were shown in generalized linear models with a logit link, and the results were relatively stable in crude, partial, and full models with ORs (95% CIs) for delayed cerebral ischemia. Subgroup analysis showed no significant subgroup differences in the effect of CysC on delayed cerebral ischemia. There was also no interaction effect between CysC and other confounders. Patients in the high CysC group had a higher risk of delayed cerebral ischemia than those in the low CysC group before and after propensity score matching. CysC level could be an independent predictor for the risk of delayed cerebral ischemia after endovascular treatment of aneurysmal subarachnoid hemorrhage.

Hemodynamic response and clinical outcome following intravenous milrinone plus norepinephrine-based hyperdynamic hypertensive therapy in patients suffering secondary cerebral ischemia after aneurysmal subarachnoid hemorrhage

Purpose

Intravenous and intra-arterial milrinone as a rescue measure for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) has been adopted by several groups, but so far, evidence for the clinical benefit is unclear and effect on brain perfusion is unknown. The aim of the actual analysis was to define cerebral hemodynamic effects and outcome of intravenous milrinone plus norepinephrine supplemented by intra-arterial nimodipine as a rescue strategy for DCI following aneurysmal SAH.

Methods

Of 176 patients with aneurysmal SAH treated at our neurosurgical department between April 2016 and March 2021, 98 suffered from DCI and were submitted to rescue therapy. For the current analysis, characteristics of these patients and clinical response to rescue therapy were correlated with hemodynamic parameters, as assessed by CT angiography (CTA) and perfusion CT. Time to peak (TTP) delay in the ischemic focus and the volume with a TTP delay of more than 4 s (T4 volume) were used as hemodynamic parameters.

Results

The median delay to neurological deterioration following SAH was 5 days. Perfusion CT at that time showed median T4 volumes of 40 cc and mean focal TTP delays of 2.5 ± 2.1 s in these patients. Following rescue therapy, median T4 volume decreased to 10 cc and mean focal TTP delay to 1.7 ± 1.9 s. Seventeen patients (17% of patients with DCI) underwent additional intra-arterial spasmolysis using nimodipine. Visible resolution of macroscopic vasospasm on CTA was observed in 43% patients with DCI and verified vasospasm on CTA, including those managed with additional intra-arterial spasmolysis. Initial WFNS grade, occurrence of secondary infarction, ischemic volumes and TTP delays at the time of decline, the time to clinical decline, and the necessity for additional intra-arterial spasmolysis were identified as the most important features determining neurological outcome at 6 months.

Conclusion

The current analysis shows that cerebral perfusion in the setting of secondary cerebral ischemia following SAH is measurably improved by milrinone and norepinephrine–based hyperdynamic therapy. A long-term clinical benefit by the addition of milrinone appears likely. Separation of the direct effect of milrinone from the effect of induced hypertension is not possible based on the present dataset.

Whole-Brain Permeability Analysis on Admission Improves Prediction of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

PURPOSE

To evaluate the changes of blood-brain barrier permeability (BBBP) after aneurysmal subarachnoid hemorrhage (aSAH) and find out whether BBBP within 24 h after onset can further improve prediction of delayed cerebral ischemia (DCI).

METHODS

CT perfusion (CTP) was performed within 24 h after onset and in the DCI time window (DCITW). Whole brain average values of flow extraction product (mK^trans), qualitative and quantitative CTP parameters, and clinical data were compared between DCI and non-DCI groups. The changes of mK^trans were analysed using a Paired t test. Multivariate logistic regression analysis and ROC analyses were performed to identify predictors of DCI and evaluate the predictive performance.

RESULTS

One hundred and forty of 179 consecutive patients were included, 45 of whom (32%) developed DCI. mK^trans was higher in the DCI group both on admission and in the DCITW (P<0.001). mK^trans decreased significantly in the non-DCI group (P=0.003), but not in DCI group (P=0.285). Multivariate logistic regression analysis showed that mK^trans (OR=1.07, 95%CI: 1.03-1.11, P<0.001), World Federation of Neurosurgery Scale (OR=6.73, 95%CI: 1.09-41.41, P=0.040), Hunt-Hess grade (OR=0.16, 95%CI: 0.02-1.19, P=0.073), modified Fisher Score (OR=3.74, 95%CI: 1.30-10.75, P=0.014), and qualitative CTP (OR=4.31, 95%CI: 1.49-12.47, P=0.007) were independent predictors of DCI. The model with K^trans produced a larger AUC of 0.88 (95%CI: 0.81-0.95), with corresponding sensitivity and specificity of 84% and 86%, respectively.

CONCLUSION

BBBP measurement within 24 h after onset can improve the prediction of DCI. Early moderate BBB disruption may be reversible, whereas severe BBBP disruption indicates the risk of DCI.

Predictive Value of Hematologic Inflammatory Markers in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND OBJECTIVE

Our study aimed to determine the ability of hematologic markers (neutrophil/lymphocyte ratio [NLR], platelet/lymphocyte ratio, and red cell distribution width [RDW]) in predicting delayed cerebral ischemia (DCI), modified Rankin Scale scores, and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A retrospective observational 6-year review of medical records was conducted to identify all consecutive patients with aSAH admitted to the largest training hospital in the Philippines. Univariable and multivariable regression analyses were performed to determine the association of the biomarkers with the respective outcomes. Receiver operating characteristic curves were used to detect overall predictive accuracy.

RESULTS

A total of 222 patients with aSAH were included, of whom 11.71% developed DCI. Most patients with NLR ≥5.9 subsequently died (77 vs. 52%; P = 0.03). DCI was also associated with poor functional outcomes with higher modified Rankin Scale scores (3-6) on discharge (92% vs. 49%; P < 0.01), and longer duration of hospitalization (median, 20 vs. 13 days; P = 0.01). In receiver operating characteristic analyses, the value of RDW was predictive for DCI (area under the curve, 0.70; 95% confidence interval, 0.62-0.79; P < 0.01). The values of NLR (area under the curve, 0.67; 95% CI, 0.59-0.74) potentially predict functional outcome. RDW, NLR, and their combinations were poor discriminators of mortality.

CONCLUSIONS

Our study showed that some hematologic parameters analyzed could be of potential value as prognostic biomarkers in patients with aSAH. Hematologic biomarkers are widely available and practical parameters that may be of considerable clinical value in aSAH management, especially in lower-middle-income countries such as the Philippines.

Cortical Spreading Depolarizations in a Mouse Model of Subarachnoid Hemorrhage

BACKGROUND

Cortical spreading depolarizations (CSDs) are associated with worse outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH). Animal models are required to assess whether CSDs can worsen outcomes or are an epiphenomenon; however, little is known about the presence of CSDs in existing animal models. Therefore, we designed a study to determine whether CSDs occur in a mouse model of SAH.

METHODS

A total of 36 mice were included in the study. We used the anterior prechiasmatic injection model of SAH under isoflurane anesthesia. A needle was inserted through the mouse olfactory bulb with the point terminating at the base of the skull, and arterial blood or saline (100 µl) was injected over 10 s. Changes in cerebral blood volume over the entire dorsal cortical surface were assessed with optical intrinsic signal imaging for 5 min following needle insertion.

RESULTS

CSDs occurred in 100% of mice in the hemisphere ipsilateral to olfactory bulb needle insertion (CSD1). Saline-injected mice had 100% survival (n = 10). Blood-injected mice had 88% survival (n = 23 of 26). A second, delayed, CSD ipsilateral to CSD1 occurred in 31% of blood-injected mice. An increase in the time interval between CSD1 and blood injection was associated with the occurrence of a second CSD in blood-injected mice (mean intervals 26.4 vs. 72.7 s, p < 0.0001, n = 18 and 8). We observed one blood-injected animal with a second CSD in the contralateral hemisphere and observed terminal CSDs in mice that died following SAH injection.

CONCLUSIONS

The prechiasmatic injection model of SAH includes CSDs that occur at the time of needle insertion. The occurrence of subsequent CSDs depends on the timing between CSD1 and blood injection. The mouse prechiasmatic injection model could be considered an SAH plus CSD model of the disease. Further work is needed to determine the effect of multiple CSDs on outcomes following SAH.

Multidisciplinary and standardized management of patients with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

The appropriate management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) remains uncertain. We aimed to evaluate the effect of implementing a standardized protocol for detection and management of DCI after aSAH on cerebral infarction and functional outcome.

METHODS

We studied two cohorts of aSAH patients, one before (pre-implementation cohort: January 2012 to August 2014) and one after (post-implementation cohort: January 2016 to July 2018) implementation of a multidisciplinary approach, with standardized neurological and radiological assessment and risk-based medical treatment of DCI. We assessed the presence of new hypodensities on CT within 6 weeks after aSAH and categorized cerebral infarction into overall and DCI-related infarctions (hypodensities not within 48 h after IA repair and not attributable to aneurysm occlusion or intraparenchymal hematoma). Functional outcome was assessed at 3 months using the extended Glasgow outcome scale (eGOS), dichotomized into unfavorable (eGOS: 1-5) and favorable (eGOS: 6-8). We calculated odds ratios (OR) with corresponding 95% confidence intervals (CI's), and adjusted for age, WFNS grade, Fisher score, and treatment modality (aOR).

RESULTS

In the post-implementation (n = 158) versus the pre-implementation (n = 143) cohort the rates for overall cerebral infarction were 29.1% vs 46.9% (aOR: 0.41 [0.24-0.69]), for DCI-related cerebral infarction 17.7% vs. 31.5% (aOR: 0.41 [0.23-0.76]), and for unfavorable functional outcome at 3 months 37.3% vs. 53.8% (aOR: 0.30 [0.17-0.54]). For patients with DCI, the rates for unfavorable functional outcomes at 3 months in the post-implementation versus the pre-implementation cohort were 42.3% vs. 77.8% (aOR: 0.1 [0.03-0.27]).

CONCLUSIONS

A multidisciplinary approach with more frequent and standardized neurological assessment, standardized CT and CT perfusion monitoring, as well as tailored application of induced hypertension and invasive rescue therapy strategies, is associated with a significant reduction of cerebral infarction and unfavorable functional outcome after aneurysmal aSAH.

Cortical Spreading Depolarizations in Aneurysmal Subarachnoid Hemorrhage: An Overview of Current Knowledge and Future Perspectives

Despite significant advances in the management of aneurysmal subarachnoid hemorrhage (SAH), morbidity and mortality remain devastating particularly for high-grade SAH. Poor functional outcome usually results from delayed cerebral ischemia (DCI). The pathogenesis of DCI during aneurysmal SAH has historically been attributed to cerebral vasospasm, but spreading depolarizations (SDs) are now considered to play a central role in DCI. During SAH, SDs may produce an inverse hemodynamic response leading to spreading ischemia. Several animal models have contributed to a better understanding of the pathogenesis of SDs during aneurysmal SAH and provided new therapeutic approaches including N-methyl-D-aspartate receptor antagonists and phosphodiesterase inhibitors. Herein we review the current knowledge in the field of SDs' pathogenesis and we detail the key experimental and clinical studies that have opened interesting new therapeutic approaches to prevent DCI in aneurysmal SAH.

The management of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a rare event affecting relatively young patients therefore leading to a high social impact. The management of SAH follows a biphasic course with early brain injuries in the first 72 hours followed by a phase at risk of secondary deterioration due to delayed cerebral ischemia (DCI) in 20 to 30% patients. Cerebral infarction from DCI is the most preventable cause of mortality and morbidity after SAH. DCI prevention, early detection and treatment is therefore advocated. Formerly limited to the occurrence of vasospasm, DCI is now associated with multiple pathophysiological processes involving for instance the macrocirculation, the microcirculation, neurovascular units, and inflammation. Therefore, the therapeutic targets and management strategies are also evolving and are not only focused on proximal vasospasm. In this review, we describe the current knowledge of DCI pathophysiology. We then discuss the diagnosis strategies that may guide physicians at the bedside with a multimodal approach in the unconscious patient. We will present the prevention strategies that have proven efficient as well as future targets and present the therapeutic approach that is currently being developed when a DCI occurs.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT03318783.