Advances in the understanding of delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage

Ventriculitis incidence and outcomes in patients with aneurysmal subarachnoid hemorrhage: a prospective observational study

OBJECTIVE

To define the incidence of ventriculostomy-associated infections and their impact on the mortality and functional outcomes of patients with aneurysmal subarachnoid hemorrhage.

METHODS

We prospectively included all consecutive adult aneurysmal subarachnoid hemorrhage patients admitted to the neurological intensive care units of the Instituto Estadual do Cérebro Paulo Niemeyer (Rio de Janeiro, Brazil) and Hospital Cristo Redentor (Rio Grande do Sul, Brazil) who required external ventricular drains from July 2015 to December 2020. Daily clinical and laboratory variables were collected at admission and during the hospital stay. The presence of ventriculostomy-associated infections was evaluated daily, according to the Centers for Disease Control and Prevention and Infectious Diseases Society of America criteria. Hospital and 12-month outcomes were compared between patients with and without ventriculostomy-associated infections via both univariate and multivariate analyses.

RESULTS

Out of the 676 patients screened, 271 received external ventricular drains (40%) and were included in the study. The mean age was 54 years (IQR 46-63), 198 were female (72%), 47% had poor grade status (World Federation of Neurological Surgeons scale 4 and 5), and 75% had modified Fisher 3 or 4. The mean time from admission to external ventricular drain placement was 8.8 days. Ventriculostomy-associated infections developed in 127 patients (47%), and the mean time from external ventricular drain to ventriculostomy-associated infection diagnosis was 4.4 days. Hospital and 12-month mortality rates did not differ between the ventriculostomy-associated infection group and the nonventriculostomy-associated infection group (36% versus 40% and 43% versus 49%, respectively). Poor functional outcomes, defined as modified Rankin scores of 4 to 6, showed no difference between groups at hospital discharge (ventriculostomy-associated infections 75% versus nonventriculostomy-associated infections 73%; p = NS) or at 12 months (ventriculostomy-associated infections 49% versus nonventriculostomy-associated infections 53%; p = NS).

CONCLUSION

Ventriculostomy-associated infections are common complications after aneurysmal subarachnoid hemorrhage. Although it was not associated with hospital mortality or functional outcomes in our cohort, improving diagnostic accuracy and preventive measures is essential for better understanding the long-term impact of one of the most severe infectious complications after aneurysmal subarachnoid hemorrhage.

Inhaled Anesthetics: Beyond the Operating Room

The development of inhaled anesthetics (IAs) has a rich history dating back many centuries. In modern times they have played a pivotal role in anesthesia and critical care by allowing deep sedation during periods of critical illness and surgery. In addition to their sedating effects, they have many systemic effects allowing for therapy beyond surgical anesthesia. In this narrative review we chronicle the evolution of IAs, from early volatile agents such as ether to the contemporary use of halogenated hydrocarbons. This is followed by a discussion of the mechanisms of action of these agents which primarily involve the modulation of lipid membrane properties and ion channel activity. IAs' systemic effects are also examined, including their effects on the cardiovascular, respiratory, hepatic, renal and nervous systems. We discuss of the role of IAs in treating systemic disease processes including ischemic stroke, delayed cerebral ischemia, status epilepticus, status asthmaticus, myocardial ischemia, and intensive care sedation. We conclude with a review of the practical and logistical challenges of utilizing IAs outside the operating room as well as directions for future research. This review highlights the expanding clinical utility of IAs and their evolving role in the management of a diverse range of disease processes, offering new avenues for therapeutic exploration beyond anesthesia.

Intraoperative Hypotension and Postoperative Newly Developed Cerebral Infarction in Patients With Aneurysmal Subarachnoid Hemorrhage: A Retrospective Cohort Study

AIMS

To investigate the association between intraoperative hypotension and newly developed cerebral infarction in patients with aneurysmal subarachnoid hemorrhage (aSAH) undergoing aneurysm clipping or coiling.

METHODS

The patients who had emergent clipping/coiling procedures for aSAH under general anesthesia were included. The major exposure was mean arterial pressure (MAP) below different absolute or relative thresholds characterized by area under curve (AUC), duration, and time-weighted average (TWA) value. The outcome was newly developed cerebral infarction. The associations between MAP and newly developed cerebral infarction were adjusted by other risk factors. Odds ratio and 95% confidence interval were used to present the statistical difference.

RESULTS

A total of 1205 patients were included in the analysis. Of these, 260 patients (21.6%) developed new cerebral infarctions assessed by computed tomography. Patients with newly developed cerebral infarction had higher incidence of modified Fisher Scale (mFS) score 3 to 4 (80.0 vs. 69.1%, p < 0.01) and longer duration of anesthesia (4.3 vs. 3.9 h, p < 0.01). In the multivariate model, the AUC-MAP (adjusted odds ratio: 1.00, 95% CI: 1.000 to 1.000, p = 0.02) and the TWA-MAP (adjusted odds ratio: 1.01, 95% CI: 1.001 to 1.024, p = 0.04) of 20% decrease from baseline were closely associated with the newly developed cerebral infarction.

CONCLUSIONS

Mean arterial pressure decreased 20% from baseline value were independently associated with postoperative newly developed cerebral infarction in patients with aSAH.

Cerebrolysin in Patients Diagnosed with Subarachnoid Hemorrhage-The Results of an Observational Cohort Study

Background: Subarachnoid hemorrhage (SAH) is associated with high mortality and a high level of disability. Progress in surgical and endovascular techniques has lowered the mortality rate in patients with SAH. However, many patients are left with neurological impairment. Objectives: In our study we wanted to examine the impact of Cerebrolysin on treatment results in patients with SAH diagnosis. Methods: The data of 47 patients, divided into Cerebrolysin (26) and non-Cerebrolysin (21) group were included. We examined the correlation between Cerebrolysin administration and additional Amantadine treatment or neuromonitoring, craniectomy, and endovascular treatment and its impact on the Glasgow Outcome Scale (GOS) score, length of stay (LOS), and mortality. Results: Our study shows that Cerebrolysin improves the mortality rate in combination with neuromonitoring in a group of patients with severe SAH. It does not affect the raw values of GOS or LOS in patients with SAH. Conclusions: Further studies with larger patient groups are needed to investigate the role of Cerebrolysin as an additional treatment in SAH.

Trajectory of mean platelet volume changes after aneurysmal subarachnoid hemorrhage in patients with or without delayed cerebral ischemia

The morbidity of aneurysmal subarachnoid hemorrhage (aSAH) remains high, particularly because of secondary cerebral lesions that significantly aggravate the primary lesions. The main type of secondary lesions is delayed cerebral ischemia (DCI), in which platelets (PLT) appear to play a key role. Mean platelet volume (MPV) is an indirect marker of platelet activation. We aimed to determine the individual trajectories of MPV over time in patients with and without DCI during the course of aSAH. This is a single-center, retrospective, longitudinal analysis of individual trajectories of MPV over time, in a cohort of aSAH patients included in the Prospective, Observational Registry of Patient with Subarachnoid Hemorrhage in Neurocritical Care Unit (ProReSHA). A mixed-effects linear regression model was used to compare the trajectories of MPV and MPV/PLT ratio between patients who developed a DCI and those who did not. A total of 3634 MPV values were collected in 587 patients. The analysis of MPV as a function of DCI occurrence showed a significant difference in the trajectory over time between patients with DCI and those without, with an estimate of 0.02 (95%CI 0.01, 0.04, p = 0.009). The analysis of the MPV/PLT ratio as a function of DCI occurrence and other covariates showed a significant difference in the trajectory over time only for patients with a modified Fisher score less than 3, with an estimate of -0.59 (95%CI: -0.94, -0.23, p = 0.001). The individual trajectories of MPV over time differ between patients with DCI and those without. However, MPV values vary greatly over time and between patients. Thus it does not appear as a reliable biomarker for stratifying patients based on their specific risk of developing DCI. ClinicalTrials.gov identifier: (NCT02890004), registered in August 2016.

Ultrasound-Induced Release Profile of Nimodipine from Drug-Loaded Block Copolymers after Singular vs. Repeated Sonication: In Vitro Analysis in Artificial Cerebrospinal Fluid

OBJECTIVE

Nimodipine still represents a unique selling point in the prevention of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). Its intrathecal effect is limited by a low oral bioavailability, leading to the development of nanocarrier systems to overcome this limitation. This study investigated the ultrasound-induced release profile of nimodipine from drug-loaded copolymers in artificial cerebrospinal fluid (CSF) within 72 h after a singular versus repeated sonication.

METHODS

Pluronic® F127 copolymers (Sigma-Aldrich, Taufkirchen, Germany)were loaded with nimodipine by direct dissolution. Spontaneous and on-demand drug release by ultrasound (1 MHz at 1.7 W/cm2) was determined in artificial cerebrospinal fluid using the dialysis bag method. Nimodipine concentrations were measured at predefined time points within 72 h of sonication.

RESULTS

Spontaneous release of nimodipine was enhanced by ultrasound application with significantly increased nimodipine concentrations two hours after a repeated sonication compared to a singular sonication (median 1.62 vs. 17.48 µg/µL, p = 0.04). A further trend was observed after four hours (median 1.82 vs. 22.09 µg/µL, p = 0.06). There was no difference in the overall nimodipine concentrations between the groups with a singular versus repeated sonication (357.2 vs. 540.3 µg/µL, p = 0.60) after 72 h.

CONCLUSIONS

Repeated sonication resulted in an acceleration of nimodipine release from the drug-loaded copolymer in a CSF medium. These findings confirm the proof of principle of an on-demand guidance of nimodipine release from nimodipine-loaded nanodrugs by means of ultrasound, which suggests that evaluating the concept in an animal model may be appropriate.

Cortical Spreading Depolarization and Delayed Cerebral Ischemia; Rethinking Secondary Neurological Injury in Subarachnoid Hemorrhage

Poor outcomes in Subarachnoid Hemorrhage (SAH) are in part due to a unique form of secondary neurological injury known as Delayed Cerebral Ischemia (DCI). DCI is characterized by new neurological insults that continue to occur beyond 72 h after the onset of the hemorrhage. Historically, it was thought to be a consequence of hypoperfusion in the setting of vasospasm. However, DCI was found to occur even in the absence of radiographic evidence of vasospasm. More recent evidence indicates that catastrophic ionic disruptions known as Cortical Spreading Depolarizations (CSD) may be the culprits of DCI. CSDs occur in otherwise healthy brain tissue even without demonstrable vasospasm. Furthermore, CSDs often trigger a complex interplay of neuroinflammation, microthrombi formation, and vasoconstriction. CSDs may therefore represent measurable and modifiable prognostic factors in the prevention and treatment of DCI. Although Ketamine and Nimodipine have shown promise in the treatment and prevention of CSDs in SAH, further research is needed to determine the therapeutic potential of these as well as other agents.

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.

Clinical Characteristics and Outcomes of Patients with Aneurysmal Subarachnoid Hemorrhage: A Prospective Multicenter Study in a Middle-Income Country

BACKGROUND

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality and long-term functional impairment. Data on clinical management and functional outcomes from developing countries are scarce. We aimed to define patient profiles and clinical practices and evaluate long-term outcomes after SAH in a middle-income country.

METHODS

This was a prospective study including consecutive adult patients admitted with SAH to two reference centers in Brazil from January 2016 to February 2020. The primary outcome was functional status at 6 months using the modified Rankin Scale. Mixed multivariable analysis was performed to determine the relationship between clinical variables and functional outcomes.

RESULTS

From 471patients analyzed, the median time from symptom onset to arrival at a study center was 4 days (interquartile range 0-9). Median age was 55 years (interquartile range 46-62) and 353 (75%) patients were women. A total of 426 patients (90%) were transferred from nonspecialized general hospitals, initial computed tomography revealed thick hemorrhage in 73% of patients (modified Fisher score of 3 or 4), and 136 (29%) had poor clinical grade (World Federation of Neurological Surgeons score of 4 or 5). A total of 312 (66%) patients underwent surgical clipping, and 119 (25%) underwent endovascular coiling. Only 34 patients (7%) underwent withdrawal or withholding of life-sustaining therapy during their hospital stay, and in-hospital mortality was 24%. A total of 187 (40%) patients had an unfavorable long-term functional outcome (modified Rankin Scale score of 4 to 6). Factors associated with unfavorable outcome were age (adjusted odds ratio [OR] 1.05, 95% confidence interval [CI] 1.03-1.08), hypertension (adjusted OR 1.81, 95% CI 1.04-3.16), poor clinical grade (adjusted OR 4.92, 95% CI 2.85-8.48), external ventricular drain (adjusted OR 3.8, 95% CI 2.31-6.24), postoperative deterioration (adjusted OR 2.33, 95% CI 1.32-4.13), cerebral infarction (adjusted OR 3.16, 95% CI 1.81-5.52), rebleeding (adjusted OR 2.95, 95% CI 1.13-7.69), and sepsis (adjusted OR 2.68, 95% CI 1.42-5.05).

CONCLUSIONS

Our study demonstrated that SAH management in a middle-income country diverges significantly from published cohorts and current guidelines, despite comparable clinical profiles on presentation and admission to high-volume referral centers. Earlier aneurysm occlusion and increased use of endovascular therapy could potentially reduce modifiable in-hospital complications and improve functional outcomes in Brazil.

MicroRNA cerebrospinal fluid profile during the early brain injury period as a biomarker in subarachnoid hemorrhage patients

Introduction

Delayed cerebral ischemia (DCI) is a dreadful complication present in up to 30% of patients with spontaneous subarachnoid hemorrhage (SAH). Indeed, DCI is one of the main causes of long-term disability in SAH, yet its prediction and prevention are troublesome in poor-grade SAH cases. In this prospective study, we explored the potential role of micro ribonucleic acid (microRNA, abbreviated miRNAs)-small non-coding RNAs involved in clue gene regulation at the post-transcriptional level-as biomarkers of neurological outcomes in SAH patients.

Methods

We analyzed the expression of several miRNAs present in the cerebrospinal fluid (CSF) of SAH patients during the early stage of the disease (third-day post-hemorrhage). NanoString Technologies were used for the characterization of the CSF samples.

Results

We found an overexpression of miRNAs in the acute stage of 57 SAH in comparison with 10 non-SAH controls. Moreover, a differential expression of specific miRNAs was detected according to the severity of clinical onset, but also regarding the development of DCI and the midterm functional outcomes.

Conclusion

These observations reinforce the potential utility of miRNAs as prognostic and diagnostic biomarkers in SAH patients. In addition, the identification of specific miRNAs related to SAH evolution might provide insights into their regulatory functions of pathophysiological pathways, such as the TGF-β inflammatory pathway and blood-brain barrier disruption.

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.

Ultrasound-Induced Release of Nimodipine from Drug-Loaded Block Copolymer Micelles: In Vivo Analysis

Nimodipine prevents cerebral vasospasm and improves functional outcome after aneurysmal subarachnoid hemorrhage (aSAH). The beneficial effect is limited by low oral bioavailability of nimodipine, which resulted in an increasing use of nanocarriers with sustained intrathecal drug release in order to overcome this limitation. However, this approach facilitates only a continuous and not an on-demand nimodipine release during the peak time of vasospasm development. In this study, we aimed to assess the concept of controlled drug release from nimodipine-loaded copolymers by ultrasound application in the chicken chorioallantoic membrane (CAM) model. Nimodipine-loaded copolymers were produced with the direct dissolution method. Vasospasm of the CAM vessels was induced by means of ultrasound (Physiomed, continuous wave, 3 MHz, 1.0 W/cm2). The ultrasound-mediated nimodipine release (Physiomed, continuous wave, 1 MHz, 1.7 W/cm2) and its effect on the CAM vessels were evaluated. Measurements of vessel diameter before and after ultrasound-induced nimodipine release were performed using ImageJ. The CAM model could be successfully carried out in all 25 eggs. After vasospasm induction and before drug release, the mean vessel diameter was at 57% (range 44-61%) compared to the baseline diameter (set at 100%). After ultrasound-induced drug release, the mean vessel diameter of spastic vessels increased again to 89% (range 83-91%) of their baseline diameter, which was significant (p = 0.0002). We were able to provide a proof of concept for in vivo vasospasm induction by ultrasound application in the CAM model and subsequent resolution by ultrasound-mediated nimodipine release from nanocarriers. This concept merits further evaluation in a rat SAH model.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sensorineural hearing loss due to delayed cerebral ischemia in bilateral auditory cortices following aneurysmal subarachnoid hemorrhage: illustrative case

BACKGROUND

Recognizing rare signs of delayed cerebral ischemia (DCI) is crucial to caring for patients with subarachnoid hemorrhage. The authors presented a case of central hearing loss that occurred during the clinical course of a patient treated for aneurysmal subarachnoid hemorrhage.

OBSERVATIONS

The patient had a ruptured right posterior communicating artery aneurysm successfully treated with coil embolization but later developed severe vasospasm and DCI. She developed bilateral hearing loss, and imaging revealed DCI to the left temporal lobe and the right auditory cortex. Computed tomography angiography and digital subtraction angiography demonstrated severe vasospasm of bilateral internal carotid arteries, bilateral middle cerebral arteries, and bilateral anterior cerebral arteries. One month after hospitalization, the patient had recovered fully neurologically intact except for persistent hearing loss.

LESSONS

This case serves to teach important neuroanatomical features and discuss the unique pathophysiology of DCI affecting the auditory cortex.

Outcomes after Flow Diverter Treatment in Subarachnoid Hemorrhage: A Meta-Analysis and Development of a Clinical Prediction Model (OUTFLOW)

Background: patients with a subarachnoid hemorrhage (SAH) might need a flow diverter (FD) placement for complex acutely ruptured intracranial aneurysms (IAs). We conducted a meta-analysis and developed a prediction model to estimate the favorable clinical outcome after the FD treatment in acutely ruptured IAs. Methods: a systematic literature search was performed from 2010 to January 2021 in PubMed and Embase databases. Studies with more than five patients treated with FDs within fifteen days were included. In total, 1157 studies were identified. The primary outcome measure was the favorable clinical outcome (mRS 0–2). Secondary outcome measures were complete occlusion rates, aneurysm rebleeding, permanent neurologic deficit caused by procedure-related complications, and all-cause mortality. A prediction model was constructed using individual patient-level data. Results: 26 retrospective studies with 357 patients and 368 aneurysms were included. The pooled rates of the favorable clinical outcome, mortality, and complete aneurysm occlusion were 73.7% (95% CI 64.7–81.0), 17.1% (95% CI 13.3–21.8), and 85.6% (95% CI 80.4–89.6), respectively. Rebleeding occurred in 3% of aneurysms (11/368). The c-statistic of the final model was 0.83 (95% CI 0.76–0.89). All the studies provided a very low quality of evidence. Conclusions: FD treatment can be considered for complex ruptured IAs. Despite high complication rates, the pooled clinical outcomes seem favorable. The prediction model needs to be validated by larger prospective studies before clinical application.

DCI after Aneurysmal Subarachnoid Hemorrhage Is Related to the Expression of MFG-E8

Objective

To explore the predictive value of milk fat globule epidermal growth factor 8 (MFG-E8) in the occurrence of delayed cerebral ischemia (DCI) after an aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We recruited 32 patients with aSAH as the case group and 24 patients with unruptured aneurysms as the control group. Serum MFG-E8 levels were measured by western blot and enzyme-linked immunosorbent assay. We analyzed the relationship between MFG-E8 levels and the risk of DCI.

Results

The levels of serum MFG-E8 in the case group (mean = 11160.9 pg/mL) were significantly higher than those in the control group (mean = 3081.0 pg/mL, p < 0.001). MFG-E8 levels highly correlated with the World Federation of Neurosurgical Societies (WFNS) and modified Fisher scores (r = -0.691 and - 0.767, respectively, p < 0.001). In addition, MFG-E8 levels in patients with DCI (5882.7 ± 3162.4 pg/mL) were notably higher than those in patients without DCI (15818.2 ± 3771.6 pg/mL, p < 0.001). A receiver operating characteristic curve showed that the occurrence of DCI could effectively be predicted by MFG-E8 (area under the curve = 0.976, 95%CI = 0.850-1.000). Kaplan-Meier survival analysis showed a remarkable decrease in the incidence of DCI in case group individuals with high levels of MFG-E8 (≥11160.9 pg/mL, p < 0.001).

Conclusion

MFG-E8 may be a useful predictive marker for DCI after an aSAH and could be a promising surrogate end point.

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.

Pathophysiology of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage: A Review

Delayed cerebral ischemia is a major predictor of poor outcomes in patients who suffer subarachnoid hemorrhage. Treatment options are limited and often ineffective despite many years of investigation and clinical trials. Modern advances in basic science have produced a much more complex, multifactorial framework in which delayed cerebral ischemia is better understood and novel treatments can be developed. Leveraging this knowledge to improve outcomes, however, depends on a holistic understanding of the disease process. We conducted a review of the literature to analyze the current state of investigation into delayed cerebral ischemia with emphasis on the major themes that have emerged over the past decades. Specifically, we discuss microcirculatory dysfunction, glymphatic impairment, inflammation, and neuroelectric disruption as pathological factors in addition to the canonical focus on cerebral vasospasm. This review intends to give clinicians and researchers a summary of the foundations of delayed cerebral ischemia pathophysiology while also underscoring the interactions and interdependencies between pathological factors. Through this overview, we also highlight the advances in translational studies and potential future therapeutic opportunities.

Compromised regulation of the rat brain parenchymal arterioles in vasopressin-associated acute hyponatremia

OBJECTIVE

In this study, we examined the effect of acute hyponatremia associated with vasopressin (AVP) on the responses of the isolated rat's MCAs and PAs to acidosis, nitric oxide donor (SNAP) and to endothelium-dependent vasodilator ATP.

METHODS

The studies were performed on isolated, perfused and pressurized MCAs and PAs in control conditions and during AVP-associated hyponatremia. Hyponatremia was induced in vitro by lowering Na⁺ concentration from 144 to 121 mmol/L in intra- and extravascular fluid in the presence of AVP.

RESULTS

Parenchymal arterioles showed greater response to an increase in H⁺ and K⁺ ions concentration and to ATP in comparison with MCAs in control normonatremic conditions. Both PAs and MCAs constricted in response to acute hyponatremia associated with AVP. Interestingly, disordered regulation of vascular tone was observed in PAs but not in MCAs. The abnormalities in the regulation comprised a significant reduction of PA response to acidosis and the absence of the response to the administration of SNAP or ATP.

CONCLUSIONS

Arginine vasopressin-associated hyponatremia leads to constriction and dysregulation of PAs which may impair neurovascular coupling.

Clinical usefulness of early serial measurements of C-reactive protein as outcome predictors in patients with subarachnoid hemorrhage

BACKGROUND

The purpose of this study was to evaluate the role of C-reactive protein (CRP) in predicting neurological outcomes of patients with subarachnoid hemorrhage (SAH).

METHODS

In this retrospective, observational study of adult patients with SAH treated between January 2012 and June 2017. Initial CRP levels collected within 24 h from the onset of SAH, the follow-up CRP levels were measured. The primary outcome was neurological status at six-month follow-up assessed with the Glasgow Outcome Scale (GOS, 1 to 5).

RESULTS

Among 156 patients with SAH, 145 (92.9%) survived until discharge. Of these survivors, 109 (69.9%) manifested favorable neurological outcomes (GOS of 4 or 5). Initial CRP levels on admission and maximal CRP levels within four days were significantly higher in the group with poor neurological outcome compared with those manifesting favorable neurological outcomes (P = 0.022, P < 0.001, respectively). However, the clearance of CRPs did not differ significantly between the two groups (P = 0.785). Analysis of the receiver operating characteristic curve for prediction of poor neurological outcome showed that the performance of the maximal CRP was significantly better compared with the initial CRP or the clearance of CRP (P = 0.007, P < 0.001, respectively). In this study, the effect of CRP on neurological outcomes differed according to surgical clipping. The maximal CRP levels within four days facilitate the prediction of neurological outcomes of SAH patients without surgical clipping (C-statistic: 0.856, 95% confidence interval [CI]: 0.767-0.921). However, they were poorly associated with neurological prognoses in SAH patients who underwent surgical clipping (C-statistic: 0.562, 95% CI: 0.399-0.716). Multivariable logistic regression analysis revealed that age (adjusted odds ratio [OR]: 1.10, 95% CI: 1.052-1.158), initial Glasgow Coma Scale (adjusted OR: 0.74, 95% CI: 0.647-0.837), and maximal CRP without surgical clipping (adjusted OR: 1.27, 95% CI: 1.066-1.516) were significantly associated with poor neurological outcomes in SAH patients.

CONCLUSIONS

Early serial measurements of CRP may be used to predict neurological outcomes of SAH patients. Furthermore, maximal CRP levels within four days post-SAH are significantly correlated with poor neurological outcomes.

Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil

Background:

The aim of the study was to characterize the clinical profile of patients with anterior communicating artery (ACoA) aneurysms and examine potential correlations between clinical findings, aneurysm morphology, and outcome.

Methods:

A review of medical records and diagnostic neuroimaging reports of patients treated at a neurosurgical service in Porto Alegre, Brazil, between August 2008 and January 2015 was performed.

Results:

During the period, 100 patients underwent surgery for ACoA aneurysms. Fifteen had unruptured aneurysms and 85 had ruptured aneurysms. Ruptured aneurysms had a higher aspect ratio than unruptured ones (2.37 ± 0.71 vs. 1.93 ± 0.51, P = 0.02). Intraoperative rupture occurred in 3%, and temporary clipping was performed in 15%. Clinical vasospasm occurred in 43 patients with ruptured aneurysms (50.6%). Overall, mortality was 26%; 25 patients in the ruptured group (29.4%) and one in the unruptured group (6%). The Glasgow Outcome Scale (GOS) was favorable (GOS 4 or 5) in 54% of patients, significantly more so in those with unruptured aneurysms (P = 0.01). In patients with ruptured aneurysms, mortality was associated with preoperative Hunt and Hess (HH) score (P < 0.001), hydrocephalus (P < 0.001), and clinical complications (P < 0.001). Unfavorable outcomes were associated with HH score (P < 0.001), Fisher grade (P = 0.015), clinical vasospasm (P = 0.012), external ventricular drain (P = 0.015), hydrocephalus (P < 0.001), and presence of clinical complications (P = 0.001). In patients with unruptured aneurysms, presence of clinical complications was the only factor associated with mortality (P < 0.001).

Conclusion:

Despite advances in the management of subarachnoid hemorrhage and surgical treatment of aneurysms, mortality is still high, especially due to clinical complications.

Incidence and impact of sepsis on long-term outcomes after subarachnoid hemorrhage: a prospective observational study

Background

Aneurysmal subarachnoid hemorrhage (SAH) is an acute cerebrovascular disease associated with high mortality and long-term functional impairment among survivors. Systemic inflammatory responses after acute injury and nosocomial infections are frequent complications, making the management of these patients challenging. Here, we hypothesized that sepsis might be associated with early and long-term mortality and functional outcomes. Our objective was to define the incidence of sepsis, diagnosed prospectively with the Sepsis-3 criteria, and to determine its impact on mortality and functional outcomes of patients with SAH.

Methods

We prospectively included all adult patients with aneurysmal SAH admitted to the intensive care unit (ICU) of a reference center between April 2016 and May 2018. Daily clinical and laboratory follow-up data were analyzed during the first 14 days, with data collected on sepsis according to the Sepsis-3 criteria. The main outcome was the functional outcome using the Modified Rankin Scale (mRS), which was assessed at hospital discharge and 3, 6 and 12 months post-discharge.

Results

In total, 149 patients were enrolled. The incidence of sepsis was 28%. Multivariable logistic regression analysis revealed that death or functional dependence (defined as an mRS score of 4 to 6) at hospital discharge was independently associated with sepsis (OR 3.4, 95% CI 1.16–9.96, p = 0.026) even after controlling for World Federation of Neurological Surgeons (WFNS) Scale (OR 4.66, 95% CI 1.69–12.88, p = 0.003), hydrocephalus (OR 4.55, 95% CI 1.61–12.85, p = 0.004) and DCI (OR 3.86, 95% CI 1.39–10.74, p = 0.01). Long-term follow-up mortality rates were significantly different in the septic and nonseptic groups (log-rank test p < 0.0001). The mortality rate of septic patients was 52.5%, and that of nonseptic patients was 16%.

Conclusion

Sepsis plays a significant role in the outcomes of patients with SAH, affecting both mortality and long-term functional outcomes. Combining high-level neurocritical care management of neurological complications and the optimal diagnosis and management of sepsis may effectively reduce secondary brain injury and improve patients’ outcomes after SAH.

The prognostic value of optic nerve sheath diameter in patients with subarachnoid hemorrhage

BACKGROUND

We evaluated the role of optic nerve sheath diameter (ONSD) using brain computed tomography (CT) in predicting neurological outcomes of patients with subarachnoid hemorrhage (SAH).

METHODS

This was a retrospective, multicenter, observational study of adult patients with SAH admitted between January 2012 and June 2017. Initial brain CT was performed within 12 h from onset of SAH, and follow-up brain CT was performed within 24 h from treatment of a ruptured aneurysm. Primary outcome was neurological status at 6-month follow-up assessed with the Glasgow Outcome Scale (GOS, 1 to 5).

RESULTS

Among 223 SAH patients, 202 (90.6%) survived until discharge. Of these survivors, 186 (83.4%) manifested favorable neurological outcomes (GOS of 3, 4, or 5). In this study, the ONSDs in the group of patients with poor neurological outcome were significantly greater than those in the favorable neurological outcome group (all p < 0.01). Intracranial pressure (ICP) was monitored in 21 (9.4%) patients during the follow-up CT. A linear correlation existed between the average ONSD and ICP in simple correlation analysis (r = 0.525, p = 0.036). Analysis of the receiver  operating characteristic curve for prediction of poor neurological outcome showed that ONSD had considerable predictive value (C-statistics, 0.735 to 0.812). In addition, the performance of a composite of Hunt and Hess grade and ONSD was increasingly associated with poor neurological outcomes than the use of each marker alone.

CONCLUSIONS

ONSD measured with CT may be used in combination with clinical grading scales to improve prognostic accuracy in SAH patients.

Effect of Early Brain Infarction After Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) is an acute cerebrovascular event that leads to devastating consequences. Early brain infarction (EBI) develops very early, within the first 72 hours after bleeding, and may have a significant impact on long-term outcomes. The incidence and impact of EBI in the prognosis of aSAH remain uncertain. We performed a systematic review and meta-analysis to evaluate the incidence of EBI in patients with aSAH and determine its effect on mortality and functional outcomes.

METHODS

We performed a systematic review and meta-analysis. Inclusion criteria were 1) studies that evaluated aSAH within 72 hours after bleeding; 2) performed a brain imaging study up to 72 hours of hemorrhage; 3) used computed tomography or magnetic resonance imaging; and 4) included a description of the findings of the brain imaging study (whether or not an infarct was present).

RESULTS

Ten studies that met the criteria were included. The incidence of EBI was 17%. The risk ratio for 3-month mortality was 2.18 (95% confidence interval 1.48-3.30). The overall risk ratio for poor outcome was 2.26 (95% confidence interval 1.75-2.93).

CONCLUSIONS

EBI plays an important role in the outcome of patients with aSAH. Its significant impact could represent a new therapeutic frontier for improving outcomes of these patients.

Alpha Calcitonin Gene-Related Peptide Increases Cerebral Vessel Diameter in Animal Models of Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis

Delayed cerebral ischemia (DCI) is a life-threatening complication after subarachnoid hemorrhage. There is a strong association between cerebral vessel narrowing and DCI. Alpha calcitonin gene-related peptide (αCGRP) is a potent vasodilator, which may be effective at reducing cerebral vessel narrowing after subarachnoid hemorrhage (SAH). Here, we report a meta-analysis of data from nine in vivo animal studies identified in a systematic review in which αCGRP was administered in SAH models. Our primary outcome was change in cerebral vessel diameter and the secondary outcome was change in neurobehavioral scores. There was a 40.8 ± 8.2% increase in cerebral vessel diameter in those animals treated with αCGRP compared with controls (p < 0.0005, 95% CI 23.7–57.9). Neurobehavioral scores were reported in four publications and showed a standardized mean difference of 1.31 in favor of αCGRP (CI −0.49 to 3.12). We conclude that αCGRP reduces cerebral vessel narrowing seen after SAH in animal studies but note that there is insufficient evidence to determine its effect on functional outcomes.