Chemical angioplasty vs. balloon plus chemical angioplasty for delayed cerebral ischemia: a pilot study of PbtO2 outcomes.

BACKGROUND: Delayed cerebral ischaemia (DCI) is a major cause of morbidity and mortality after aneurysmal subarachnoid haemorrhage (aSAH). Chemical angioplasty (CA) and transluminal balloon angioplasty (TBA) are used to treat patients with refractory vasospasm causing DCI. Multi-modal monitoring including brain tissue oxygenation (PbtO2) is routinely used at this centre for early detection and management of DCI following aSAH. In this single-centre pilot study, we are comparing these two treatment modalities and their effects on PbtO2. METHODS: Retrospective case series of patients with DCI who had PbtO2 monitoring as part of their multimodality monitoring and underwent either CA or TBA combined with CA. PbtO2 values were recorded from intra-parenchymal Raumedic NEUROVENT-PTO® probes. Data were continuously collected and downloaded as second-by-second data. Comparisons were made between pre-angioplasty PbtO2 and post-angioplasty PbtO2 median values (4 h before angioplasty, 4 h after and 12 h after). RESULTS: There were immediate significant improvements in PbtO2 at the start of intervention in both groups. PbtO2 then increased by 13 mmHg in the CA group and 15 mmHg in the TBA plus CA group in the first 4 h post-intervention. This improvement in PbtO2 was sustained for the TBA plus CA group but not the CA group. CONCLUSION: Combined balloon plus chemical angioplasty results in more sustained improvement in brain tissue oxygenation compared with chemical angioplasty alone. Our findings suggest that PbtO2 is a useful tool for monitoring the response to angioplasty in vasospasm.

CT Imaging Computed Tomography/Computed Tomography Angiography/Perfusion in Acute Ischemic Stroke and Vasospasm.

Computed tomography (CT), CT angiography (CTA), and CT perfusion (CTP) play crucial roles in the comprehensive evaluation and management of acute ischemic stroke, aneurysmal subarachnoid hemorrhage (SAH), and vasospasm. CTP provides functional data about cerebral blood flow, allowing radiologists, neurointerventionalists, and stroke neurologists to more accurately delineate the volume of core infarct and ischemic penumbra allowing for patient-specific treatment decisions to be made. CTA and CTP are used in tandem to evaluate for vasospasm associated with aneurysmal SAH and can help provide an insight into the physiologic impact of angiographic vasospasm, better triaging patients for medical and interventional treatment.

Cisternal nicardipine for prevention of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a comparative retrospective cohort study.

PURPOSE: Intrathecal vasoactive drugs have been proposed in patients with aneurysmal subarachnoid hemorrhage (aSAH) to manage cerebral vasospasm (CV). We analyzed the efficacy of intracisternal nicardipine compared to intraventricular administration to a control group (CG) to determine its impact on delayed cerebral ischemia (DCI) and functional outcomes. Secondary outcomes included the need for intra-arterial angioplasties and the safety profile. METHODS: We performed a retrospective analysis of prospectively collected data of all adult patients admitted for a high modified Fisher grade aSAH between January 2015 and April 2022. All patients with significant radiological CV were included. Three groups of patients were defined based on the CV management: cisternal nicardipine (CN), ventricular nicardipine (VN), and no intrathecal nicardipine (control group). RESULTS: Seventy patients met the inclusion criteria. Eleven patients received intracisternal nicardipine, 18 intraventricular nicardipine, and 41 belonged to the control group. No cases of DCI were observed in the CN group (p = 0.02). Patients with intracisternal nicardipine had a reduced number of intra-arterial angioplasties when compared to the control group (p = 0.03). The safety profile analysis showed no difference in complications across the three groups. Intrathecal (ventricular or cisternal) nicardipine therapy improved functional outcomes at 6 months (p = 0.04) when compared to the control group. CONCLUSION: Administration of intrathecal nicardipine for moderate to severe CV reduces the rate of DCI and improved long-term functional outcomes in patients with high modified Fisher grade aSAH. This study also showed a relative benefit of cisternal over intraventricular nicardipine, thereby reducing the number of angioplasties performed in the post-treatment phase. However, these preliminary results should be confirmed with future prospective studies.

Reversible Cerebral Vasoconstriction Syndrome and Female Sex: A Narrative Review.

Reversible cerebral vasoconstriction syndrome (RCVS) refers to segmental, multifocal constriction of intracranial arteries along with acute headache and resolves within weeks. It occurs more commonly in women, and 1 well-known manifestation of RCVS is postpartum angiopathy. Furthermore, the female sex is included in scoring systems designed to assist with diagnosing RCVS. Nonetheless, the literature is mixed regarding the true role of female and pregnancy-related factors in the pathophysiology of RCVS, and it is similarly unclear whether management of this disorder differs by sex. Given the association of RCVS with female sex and the importance of highlighting, recognizing, and managing stroke etiologies in women, herein, the author reviews what is currently known and unknown about the topic of RCVS in women.

Factors Influencing Discontinuation of Clazosentan Therapy in Elderly Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study from a Japanese Single Center.

BACKGROUND Clazosentan is an endothelin receptor antagonist approved in Japan for preventing cerebral vasospasm and vasospasm-associated cerebral ischemia and infarction. This study included elderly patients aged ≥75 years with aneurysmal subarachnoid hemorrhage (SAH) and aimed to evaluate the factors associated with discontinuing anti-vasospasm therapy with clazosentan. MATERIAL AND METHODS In this single-center retrospective observational study, we extracted diagnostic and therapeutic work-up data of consecutive 40 patients with SAH treated with clazosentan infusion (10 mg/h) as first-line anti-vasospasm therapy between May 2022 and August 2023. Patient data were compared between the discontinued and completed groups, and related factors for the discontinuation were further analyzed. RESULTS Clazosentan was discontinued in 22% (n=9) of patients due to intolerable dyspnea accompanied by hypoxemia at 5±3 days after therapy initiation, in which 44% (n=4) were elderly (≥75 years). Patients who discontinued clazosentan therapy showed significantly lower urine volumes compared with those who completed the therapy (P<0.05). Multivariate regression analysis revealed that day-to-day urine volume variance and older age were independent risk factors for drug cessation (P<0.05). The cut-off value for predicting clazosentan discontinuation was -0.7 mL/kg/h with sensitivity of 86% and specificity of 75% (area under the curve: 0.76±0.10; 95% confidence interval: 0.56-0.96; P=0.035). CONCLUSIONS Our results suggest that approximately 20% of SAH patients suffered from intolerable respiratory symptoms attributable to hypoxemia. We found that both reduced day-to-day urine volume variation and older age are independent risk factors for drug discontinuation.

CTA Supplemented by CTP Increases Interrater Reliability and Endovascular Treatment Use in Patients with Aneurysmal SAH.

BACKGROUND AND PURPOSE: Cerebral vasospasm is a common complication of aneurysmal SAH and remains a risk factor for delayed cerebral ischemia and poor outcome. The interrater reliability of CTA in combination with CTP has not been sufficiently studied. We aimed to investigate the reliability of CTA alone and in combination with CTP in the detection of cerebral vasospasm and the decision to initiate endovascular treatment. MATERIALS AND METHODS: This is a retrospective single-center study including patients treated for aneurysmal SAH. Inclusion criteria were a baseline CTA and follow-up imaging including CTP due to suspected vasospasm. Three neuroradiologists were asked to grade 15 intracranial arterial segments in 71 cases using a tripartite scale (no, mild <50%, or severe >50% vasospasm). Raters further evaluated whether endovascular treatment should be indicated. The ratings were performed in 2 stages with a minimum interval of 6 weeks. The first rating included only CTA images, whereas the second rating additionally encompassed CTP images. All raters were blinded to any clinical information of the patients. RESULTS: Interrater reliability for per-segment analysis of vessels was highly variable (κ = 0.16-0.61). We observed a tendency toward higher interrater reliability in proximal vessel segments, except for the ICA. CTP did not improve the reliability for the per-segment analysis. When focusing on senior raters, the addition of CTP images resulted in higher interrater reliability for severe vasospasm (κ = 0.28; 95% CI, 0.10-0.46 versus κ = 0.46; 95% CI, 0.26-0.66) and subsequently higher concordance (κ = 0.23; 95% CI, -0.01-0.46 versus κ = 0.73; 95% CI, 0.55-0.91) for the decision of whether endovascular treatment was indicated. CONCLUSIONS: CTA alone offers only low interrater reliability in the graduation of cerebral vasospasm. However, using CTA in combination with CTP might help, especially senior neuroradiologists, to increase the interrater reliability to identify severe vasospasm following aneurysmal SAH and to increase the reliability regarding endovascular treatment decisions.

Risks of nimodipine dose reduction during the high-risk period for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Nimodipine dose reduction is recommended in case of high vasopressor demand after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess potential adverse effects of nimodipine reduction during the high-risk period for delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) between days 5 and 10 after hemorrhage. Demographic and clinical data as well as daily nimodipine dose of aSAH patients admitted between 2010 and 2019 were retrospectively analyzed. Univariable and multivariable regression analyses were performed to identify factors associated with DCI, angiographic CVS, DCI-related infarction, and unfavorable outcome. A total of 205 patients were included. Nimodipine dose reduction occurred in 108 (53%) patients ('nimodipine reduction group'), while 97 patients (47%) received the full dose ('no nimodipine reduction group'), Patients in the 'nimodipine reduction group' had significant worse WFNS and Fisher grades and developed significantly more often DCI and angiographic CVS. DCI-related infarction and unfavorable outcome were also significantly increased in the 'nimodipine reduction group.' 'Reduced nimodipine dose' was the only independent predictor for the occurrence of DCI and angiographic CVS in multivariable regression analysis. 'Poor WFNS grade' and 'reduced nimodipine dose' were identified as independent risk factors for DCI-related infarction while 'older age,' 'poor WFNS grade,' and 'reduced nimodipine dose' were associated with unfavorable outcome at 3 months after discharge. Nimodipine dose reduction during the high-risk period of DCI and CVS between days 5 and 10 after hemorrhage might abrogate the positive prognostic effects of nimodipine and should be critically evaluated.

Dexamethasone Addition Impairs the Therapeutic Effects of Nimodipine for Subarachnoid Hemorrhage: An Experimental Animal Study.

AIM: To evaluate the effects of the combination of nimodipine and dexamethasone in subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: In this study, 35 female adult Wistar Albino rats were randomly assigned to four groups: Sham (n=8), SAH with no treatment (n=9), SAH with nimodipine (n=9, oral gavage, 12 mg/kg, BID) treatment, and SAH with combined therapy with nimodipine and dexamethasone (n=9, intraperitoneally, 1mg/kg, BID). The "cisterna magna double injection of autologous blood" model was used. The animals were euthanized 5 days after the first injection. RESULTS: Of the total, five rats died before euthanasia. The SAH+Nontreatment group showed the worst score in neurological examinations, and the most severe histopathological findings were noted in terms of vasospasm. The SAH+Nimodipine group showed the best neurological score and the closest histopathological results to those of the Sham group, whereas adding dexamethasone to nimodipine treatment (the SAH+Nimodipine+Dexamethasone group) worsened the neurological and histopathological outcomes. CONCLUSION: We thus concluded that the therapeutic effects of nimodipine were impaired when combined with dexamethasone. We thus hypothesized that dexamethasone possibly induces the CYP3A4-enzyme that metabolizes nimodipine. However, it should be noted that our results are based on laboratory findings obtained on a small sample, therefore further studies with drug-drug interaction on a larger sample size through CYP3A4-enzyme and clinical confirmation are warranted.

"Aneurysmal Subarachnoid Hemorrhage and Cocaine Consumption: A Systematic Review and Metanalysis".

BACKGROUND: The use of cocaine can lead to a variety of neurologic complications, including cerebral vasoconstriction, ischemia, aneurysm formation, and aneurysm rupture. A previous study has shown that cocaine use is associated with an increased risk of subarachnoid hemorrhage (SAH). This study conducted a systematic review and meta-analysis of observational studies to assess the association between cocaine use and the risk of poor neurological outcomes and mortality in patients with SAH. METHODS: A systematic review and meta-analysis were performed following the meta-analysis of observational studies in epidemiology (MOOSE) declaration for systematic reviews and the Cochrane Manual of Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials (RCTs), nonrandomized clinical trials, and prospective and retrospective cohort studies that reported data about adults who suffered Aneurysmal Subarachnoid Hemorrhage (aSAH) after having consumed cocaine recreationally were included. Variables such as mortality, vasospasm, seizures, re-bleeding, and complications were analyzed. RESULTS: After a thorough selection process, 14 studies involving 116,141 patients, of which 2227 had a history of cocaine consumption, were included in the analysis. There was a significant increase in overall unfavorable outcomes in aSAH patients with a history of cocaine use (OR 5.51 CI 95% [4.26-7.13] P = <0.0001; I2 = 78%), with higher mortality and poor neurologic outcomes. There were no significant differences in the risk of hydrocephalus, seizures, or re-bleeding. Cocaine use was found to increase the risk of vasospasm and overall complications. CONCLUSIONS: This study insinuates that cocaine use is associated with worse clinical outcomes in aSAH patients. Despite the cocaine users did not exhibit a higher risk of certain complications such as hydrocephalus and seizures, they had an increased risk of vasospasm and overall complications. These findings highlight the importance of addressing the issue of cocaine consumption as a primary preventive measure to decrease the incidence of aSAH and improve patient outcomes.

Cilostazol May Improve Outcomes Even in Patients with Aneurysmal Subarachnoid Hemorrhage Aged 75 Years and Older: Multicenter Cohort Study and Propensity Score-Matched Analyses.

BACKGROUND: The opportunities to treat elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) are increasing globally, but the outcome remains poor. This study seeks to investigate treatment-related factors that can modify functional outcomes in patients with aSAH aged ≥75 years. METHODS: A total of 202 patients with aSAH aged ≥75 years prospectively enrolled in 9 primary stroke centers from 2013 to 2021 were retrospectively analyzed. Clinical variables including treatments for hydrocephalus, angiographic vasospasm, and delayed cerebral ischemia were compared between patients with good (modified Rankin Scale [mRS] score 0-2) and poor (mRS score 3-6) outcomes at 90 days from onset, followed by multivariate analyses to find independent outcome determinants. A modifiable treatment-related variable was evaluated after propensity score matching with adjustments for age, sex, pre-onset mRS score, aSAH severity, and treatment modality. RESULTS: More than half of patients showed World Federation of Neurological Societies grades IV-V on admission. Univariate analyses showed that advanced age, worse pre-onset mRS score, more severe neurologic status on admission, higher modified Fisher grade on admission computed tomography scans, and acute and chronic hydrocephalus were associated with poor outcomes. In contrast, administration of a phosphodiesterase type III inhibitor, cilostazol, was associated with good outcomes in both univariate (P = 0.036) and multivariate analyses (adjusted odds ratio, 0.305; 95% confidence interval, 0.097-0.955; P = 0.042). Propensity score matching analyses showed that patients treated with cilostazol had better outcomes (P = 0.016) with fewer incidences of delayed cerebral infarction (P = 0.008). CONCLUSIONS: Even in patients with aSAH aged ≥75 years, cilostazol administration may lead to better outcomes by suppressing the development of delayed cerebral infarction.

Changes in Adhesion and the Expression of Adhesion Molecules in PBMCs after Aneurysmal Subarachnoid Hemorrhage: Relation to Cerebral Vasospasm.

Aneurysmal subarachnoid hemorrhage (aSAH) is a neurovascular disease produced by extravasation of blood to the subarachnoid space after rupture of the cerebral vessels. After bleeding, the immune response is activated. The role of peripheral blood mononuclear cells (PBMCs) in this response is a current subject of research. We have analysed the changes in PBMCs of patients with aSAH and their interaction with the endothelium, focusing on their adhesion and the expression of adhesion molecules. Using an in vitro adhesion assay, we observed that the adhesion of PBMCs of patients with aSAH is increased. Flow cytometry analysis shows that monocytes increased significantly in patients, especially in those who developed vasospasm (VSP). In aSAH patients, the expression of CD162, CD49d, CD62L and CD11a in T lymphocytes and of CD62L in monocytes increased. However, the expression of CD162, CD43, and CD11a decreased in monocytes. Furthermore, monocytes from patients who developed arteriographic VSP had lower expression of CD62L. In conclusion, our results confirm that after aSAH, monocyte count and adhesion of PBMCs increase, especially in patients with VSP, and that the expression of several adhesion molecules is altered. These observations can help predict VSP and to improve the treatment of this pathology.

Impact of human serum albumin level on symptomatic cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To investigate the impact of human serum albumin (HSA) levels on symptomatic cerebral vasospasm (SCVS) in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: We retrospectively reviewed the medical records. SCVS was defined as the development of a new neurological deterioration when the cause was considered to be ischemia attributable to vasospasm after other possible causes of worsening had been excluded. The aSAH patients were divided into two groups: those with SCVS (group 1) and those without SCVS (group 2). The HSA level data on the 1st, 2nd, and 3rd day after admission was collected. Multivariate logistical regression and receiver operating characteristic (ROC) analysis were performed to evaluate the ability of HSA level to predict the development of SCVS. RESULTS: A total of 270 patients were included in our study, of which 74 (27.4%) developed SCVS. The average and lowest HSA levels were lower in group 1 (P < 0.001). In univariate logistic regression, white blood cell count, neutrophil count, and average and lowest HSA levels were associated with SCVS. After adjustment for age, CT Fisher grade, Hunt-Hess grade, and WFNS grade, both the average and lowest HSA levels remained independent predictors of SCVS (P < 0.001). The CT Fisher grade was confirmed to be an independent predictor of SCVS across each model. ROC analysis revealed that the lowest HSA level was a better predictor for SCVS than average HSA level and CT Fisher grade. CONCLUSION: Clinicians are encouraged to measure HSA levels for the first 3 days after admission to predict the occurrence of SCVS after aSAH.

Stellate Ganglion Block and Intraarterial Spasmolysis in Patients with Cerebral Vasospasm: A Retrospective Cohort Study.

BACKGROUND: In patients with symptomatic cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage who do not respond to medical therapy, urgent treatment escalation has been suggested to be beneficial for brain tissue at risk. In our routine clinical care setting, we implemented stellate ganglion block (SGB) as a rescue therapy with subsequent escalation to intraarterial spasmolysis (IAS) with milrinone for refractory CV. METHODS: In this retrospective analysis from 2012 to 2021, patients with CV following aneurysmal subarachnoid hemorrhage who received an SGB or IAS were identified. Patients were assessed through neurological examination and transcranial Doppler. Rescue therapy was performed in patients with mean cerebral blood flow velocity (CBFV) ≥ 120 cm/s and persistent neurological deterioration/intubation under induced hypertension. Patients were reassessed after therapy and the following day. The Glasgow Outcome Scale was assessed at discharge and 6-month follow-up. RESULTS: A total of 82 patients (mean age 50.16 years) with 184 areas treated with SGB and/or IAS met the inclusion criteria; 109 nonaffected areas were extracted as controls. The mean CBFV decrease in the middle cerebral artery on the following day was - 30.1 (± 45.2) cm/s with SGB and - 31.5 (± 45.2) cm/s with IAS. Mixed linear regression proved the significance of the treatment categories; other fixed effects (sex, age, aneurysm treatment modality [clipping or coiling], World Federation of Neurological Surgeons score, and Fisher score) were insignificant. In logistic regression, the presence of cerebral infarction on imaging before discharge from the intensive care unit (34/82) was significantly associated with unfavorable outcomes (Glasgow Outcome Scale ≤ 3) at follow-up. CONCLUSIONS: Stellate ganglion block and IAS decreased CBFV the following 24 h in patients with CV. We suggest SGB alone for patients with mild symptomatic CV (CBFV < 180 cm/s), while subsequent escalation to IAS proved to be beneficial in patients with refractory CV and severe CBFV elevation (CBFV ≥ 180 cm/s).

Pharmacological Prevention of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH) include early brain injury and delayed neurologic deterioration, which may result from delayed cerebral ischemia (DCI). Complex pathophysiological mechanisms underlie DCI, which often includes angiographic vasospasm (aVSP) of cerebral arteries. METHODS: Despite the study of many pharmacological therapies for the prevention of DCI in aSAH, nimodipine-a dihydropyridine calcium channel blocker-remains the only drug recommended universally in this patient population. A common theme in the research of preventative therapies is the use of promising drugs that have been shown to reduce the occurrence of aVSP but ultimately did not improve functional outcomes in large, randomized studies. An example of this is the endothelin antagonist clazosentan, although this agent was recently approved in Japan. RESULTS: The use of the only approved drug, nimodipine, is limited in practice by hypotension. The administration of nimodipine and its counterpart nicardipine by alternative routes, such as intrathecally or formulated as prolonged release implants, continues to be a rational area of study. Additional agents approved in other parts of the world include fasudil and tirilazad. CONCLUSIONS: We provide a brief overview of agents currently being studied for prevention of aVSP and DCI after aSAH. Future studies may need to identify subpopulations of patients who can benefit from these drugs and perhaps redefine acceptable outcomes to demonstrate impact.

Feasibility and Reliability of Transcranial POCUS Color-Coded Duplex Sonography Performed by Physicians of Varied Ultrasound Experience in Diagnosing Vasospasm in Aneurysmal Subarachnoid Hemorrhage.

PURPOSE: Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality, which is largely attributable to secondary complications such as vasospasm and subsequent delayed cerebral ischemia. Transcranial Doppler (TCD) is recommended for the screening of vasospasm; however, technicians are not always available. We aimed to see how feasible and reliable bedside transcranial point-of-care ultrasound (POCUS) color-coded duplex sonography was compared with formal non-imaging TCD in measuring velocities and in diagnosing vasospasm. METHODS: This was a prospective observational study that took place in the neuroscience intensive care unit at a single academic medical center. Patients with aSAH who were undergoing formal TCDs were scanned on days 2-10 of their admission by physicians of ranging ultrasound experience. Absolute velocities were compared as well as the diagnosis of vasospasm via POCUS and formal TCDs. RESULTS: A total of 226 bedside ultrasound exams were performed and compared with 126 formal TCD studies. Sonographic windows were obtained in 89.4% of patients. Scans took 6.6 minutes to complete on average by the advanced group versus 14.5 minutes in the beginner. Correlation ranged from .52 in the beginner group to .65 in the advanced. When good quality of images obtained at a depth of 4-5 cm were reviewed, correlation of mean velocities increased to .96. Overall sensitivity for diagnosing vasospasm was 75%, with a specificity of 99% and negative predictive value of 99%. CONCLUSION: Overall, POCUS TCD cannot replace a formal study performed by expert sonographers. An abbreviated POCUS scan can be performed quickly, however, particularly with more experienced operators. POCUS TCD can also feasibly detect vasospasm, and accurate velocities can be obtained by those with all levels of ultrasound experience. Care must be taken on image interpretation that velocities are obtained at an appropriate depth to ensure appropriate insonation of the MCA as well as in optimal alignment with the vessel to obtain the most accurate velocities.

Stellate Ganglion Block in Subarachnoid Hemorrhage: A Promising Protective Measure Against Vasospasm?

BACKGROUND: Stellate ganglion block (SGB) may have protective effects in patients at risk of vasospasm following subarachnoid hemorrhage (SAH) due to reduced sympathetic activity. However, the safety and clinical outcomes of SGB in this scenario are not definitively known. The objective was to evaluate the safety, clinical outcomes, and cerebral blood flow velocity in patients submitted to SGB or cervical sympathectomy with SAH. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review and meta-analysis of studies investigating SGB or cervical sympathectomy use in SAH were conducted. PubMed, Cochrane Library, and Embase were evaluated. Patients with mRS from 0 to 2, GOS from 4 to 5, or symptom resolution were considered favorable clinical outcomes. Related mortality was defined as death by vasospasm or delayed cerebral ischemia. RESULTS: The analysis included 8 studies comprising 182 patients. Only 2 studies employed SGB prophylactically. The results revealed favorable outcomes in 52% of patients (95% CI: 37%-65%). The overall incidence of complications was 2% (95% CI: 0% -26%). The mortality rate was 13% (95% CI: 7%-21%), with a vasospasm-related mortality rate of 11% (95% CI: 2%-20%). A decrease of cerebral blood flow velocity was reported in 4 studies. CONCLUSIONS: The notable reduction in cerebral blood flow velocity following SGB, alongside positive outcomes and a low occurrence of mortality and complications, highlights its significance as a therapeutic intervention for vasospasm following SAH. While the number of studies evaluating SGB as a preventive measure is limited, the promising results emphasize the importance of future research.

Conditioning-based therapeutics for aneurysmal subarachnoid hemorrhage - A critical review.

Aneurysmal subarachnoid hemorrhage (SAH) carries significant mortality and morbidity, with nearly half of SAH survivors having major cognitive dysfunction that impairs their functional status, emotional health, and quality of life. Apart from the initial hemorrhage severity, secondary brain injury due to early brain injury and delayed cerebral ischemia plays a leading role in patient outcome after SAH. While many strategies to combat secondary brain injury have been developed in preclinical studies and tested in late phase clinical trials, only one (nimodipine) has proven efficacious for improving long-term functional outcome. The causes of these failures are likely multitude, but include use of therapies targeting only one element of what has proven to be multifactorial brain injury process. Conditioning is a therapeutic strategy that leverages endogenous protective mechanisms to exert powerful and remarkably pleiotropic protective effects against injury to all major cell types of the CNS. The aim of this article is to review the current body of evidence for the use of conditioning agents in SAH, summarize the underlying neuroprotective mechanisms, and identify gaps in the current literature to guide future investigation with the long-term goal of identifying a conditioning-based therapeutic that significantly improves functional and cognitive outcomes for SAH patients.