Cerebral arterial spasm--a controlled trial of nimodipine in patients with subarachnoid hemorrhage

Therapeutic potential of stem cells in subarachnoid hemorrhage

Aneurysm rupture can result in subarachnoid hemorrhage, a condition with potentially severe consequences, such as disability and death. In the acute stage, early brain injury manifests as intracranial pressure elevation, global cerebral ischemia, acute hydrocephalus, and direct blood-brain contact due to aneurysm rupture. This may subsequently cause delayed cerebral infarction, often with cerebral vasospasm, significantly affecting patient outcomes. Chronic complications such as brain volume loss and chronic hydrocephalus can further impact outcomes. Investigating the mechanisms of subarachnoid hemorrhage-induced brain injury is paramount for identifying effective treatments. Stem cell therapy, with its multipotent differentiation capacity and anti-inflammatory effects, has emerged as a promising approach for treating previously deemed incurable conditions. This review focuses on the potential application of stem cells in subarachnoid hemorrhage pathology and explores their role in neurogenesis and as a therapeutic intervention in preclinical and clinical subarachnoid hemorrhage studies.

When transfusion causes a splitting headache: A case report and rapid review of transfusion-associated reversible cerebral vasoconstriction syndrome

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare and understudied transfusion reaction most commonly seen in adult females after correction of chronic, severe anemia. Transfusion-associated RCVS (TA-RCVS) typically presents with thunderclap headaches and one or more systemic (hypertension, nausea/vomiting) or neurologic (seizure, stroke, visual changes) symptoms within a week after red blood cell transfusion. Treatment of RCVS is based on blood pressure control; a recent study suggested that early use of nimodipine could shorten the disease course.

Flow diversion with hydrophilic polymer coating with prasugrel as single antiplatelet therapy in the treatment of acutely ruptured intracranial aneurysms: a multicenter case series, complication and occlusion rates

BACKGROUND

This study reports a multicenter experience of using hydrophilic polymer-coated (HPC) flow diverters with prasugrel single antiplatelet therapy to treat ruptured aneurysms with subarachnoid hemorrhage (SAH).

METHODS

Patients treated for intracranial aneurysms within 30 days after SAH with a p64/p48 MW HPC flow diverter were prospectively identified. Clinical presentation and outcomes, periprocedural and postprocedural complications, and degree of occlusion at follow-up were evaluated.

RESULTS

A total of 84 patients were treated in 88 sessions (54.5% women; mean age 53.3 years). Four patients (4.7%) experienced flow diverter-dependent complications. No cases of aneurysm re-rupture or hemorrhagic complications related to antiplatelet therapy were recorded. Immediate complete occlusion was achieved in 27.4% of cases (23/84). The rate of complete occlusion among survivors was 83% in early follow-up, 90.2% in mid-term follow-up, and 92.3% in the latest possible follow-up.

CONCLUSION

p64/p48 MW HPC flow diverters with prasugrel single antiplatelet therapy were associated with safety from aneurysm re-rupture and high occlusion rates at medium- and long-term follow-up in managing ruptured aneurysms. Adequate management of single antiplatelet therapy with prasugrel is crucial, particularly with higher doses than usual, to avoid both ischemic and hemorrhagic complications.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

Nimodipine-associated standard dose reductions and neurologic outcomes after aneurysmal subarachnoid hemorrhage: the era of pharmacogenomics

Nimodipine, an L-type cerebroselective calcium channel antagonist, is the only drug approved by the US Food and Drug Administration for the neuroprotection of patients with aneurysmal subarachnoid hemorrhage (aSAH). Four randomized, placebo-controlled trials of nimodipine demonstrated clinical improvement over placebo; however, these occurred before precision medicine with pharmacogenomics was readily available. The standard enteral dose of nimodipine recommended after aSAH is 60 mg every 4 h. However, up to 78% of patients with aSAH develop systemic arterial hypotension after taking the drug at the recommended dose, which could theoretically limit its neuroprotective role and worsen cerebral perfusion pressure and cerebral blood flow, particularly when concomitant vasospasm is present. We investigated the association between nimodipine dose changes and clinical outcomes in a consecutive series of 150 patients (mean age, 56 years; 70.7% women) with acute aSAH. We describe the pharmacogenomic relationship of nimodipine dose reduction with clinical outcomes. These results have major implications for future individualized dosing of nimodipine in the era of precision medicine.

Emergent Management of Spontaneous Subarachnoid Hemorrhage

OBJECTIVE

Spontaneous subarachnoid hemorrhage (SAH) carries high morbidity and mortality rates, and the emergent management of this disease can make a large impact on patient outcome. The purpose of this article is to provide a pragmatic overview of the emergent management of SAH.

LATEST DEVELOPMENTS

Recent trials have influenced practice around the use of antifibrinolytics, the timing of aneurysm securement, the recognition of cerebral edema and focus on avoiding a lower limit of perfusion, and the detection and prevention of delayed cerebral ischemia. Much of the acute management of SAH can be protocolized, as demonstrated by two updated guidelines published by the American Heart Association/American Stroke Association and the Neurocritical Care Society in 2023. However, the gaps in evidence lead to clinical equipoise in some aspects of critical care management.

ESSENTIAL POINTS

In acute management, there is an urgency to differentiate the etiology of SAH and take key emergent actions including blood pressure management and coagulopathy reversal. The critical care management of SAH is similar to that of other acute brain injuries, with the addition of detecting and treating delayed cerebral ischemia. Strategies for the detection and treatment of delayed cerebral ischemia are limited by disordered consciousness and may be augmented by monitoring and imaging technology.

Utility of Surveillance Angiography in Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study of 223 Consecutive Patients

BACKGROUND

Patients with aneurysmal subarachnoid hemorrhage (aSAH) who survive the rupture are at risk for delayed neurologic deficits and cerebral infarction. The ideal method(s) of surveillance for cerebral vasospasm, and the link between radiographic vasospasm and delayed neurologic deficits, remain controversial. We instituted a postbleed day 7 angiography protocol with the stated goals of identification of vasospasm, improving neurologic outcomes, and possibly lowering cost of care.

METHODS

We conducted a quality improvement project in which we retrospectively analyzed consecutive cases of aSAH from a single institution over a 5-year period. Patients were excluded if they did not receive treatment for their aneurysm or were < 18 years of age. We analyzed demographic and outcome information for patients managed by protocolled angiography versus those who were managed by as-needed endovascular rescue therapy. Statistical tests were performed comparing means and proportions in both cohorts, as appropriate.

RESULTS

In total, 223 patients were identified who met inclusion criteria. In total, 157 patients were identified in the protocolled day 7 angiography group, and 66 were in the nonprotocolled angiography group. Demographics were similar between the day 7 angiogram and medical management cohorts, except for a higher mean age among the latter group (p = 0.016). The protocolled angiography group underwent a significantly greater number of angiograms (p < 0.001) and had a significantly higher cost of hospitalization ($240,327 vs. $205,719, p = 0.03), with no significant difference in rate of cerebral infarction, length of intensive care unit stay, length of hospital stay, discharge location, or discharge modified Rankin Score.

CONCLUSIONS

This cohort comparison analysis draws into question the practice of protocolized cerebral angiography in patients with aSAH.

Nimodipine prophylaxis in aneurysmal subarachnoid hemorrhage, a question of tradition or evidence: A scoping review

BACKGROUND

The prophylactic use of nimodipine following subarachnoid hemorrhage is a practice established four decades ago when clinical management differed from current and the concept of Delayed Cerebral Ischemia (DCI) was not established. The applicability of the original studies is limited by the fact of not reflecting current practice; by utilising a dichotomised outcome measure such as good neurological outcome versus death and vegetative state; by applying variable dosing regimens and including all causes of poor neurological outcome different than DCI. This study aims to review the available evidence to discuss the ongoing role of nimodipine in contemporaneous clinical practice.

METHODS

PRISMA guidelines based review, evaluated the evidence on the prophylactic use of nimodipine. The following search engines: Medline, Embase, Cochrane, Web of Science and PubMed, identified Randomized Control Trials (RCTs) with neurological benefit as outcome measure and the impact of fixed versus weight-based nimodipine dosing regimens.

RESULTS

Eight RCT were selected. Three of those trials with a total of 349 patients, showed a reduction on death and vegetative state (pooled RR: 0.62; 95 % confidence interval-CI: 0.45, 0.86) related to DCI. Amongst all studies, all cause death (pooled RR = 0.73, [95 % CI: 0.56, 0.97]) favoured a fixed-dose regimen (pooled RR: 0.60; [95 % CI: 0.43, 0.85]).

CONCLUSION

Available evidence demonstrates that nimodipine only reduces the risk for DCI-related death or vegetative state and that fixed-dose regimens favour all cause infarct and death independent of DCI. Contemporaneous studies assessing the benefit of nimodipine beyond death or vegetative states and applying individualized dosing are warranted.

Is Stent Retraction to ReLieve Arterial Cerebral VaSospasm Caused by SAH (Stent-ReLACSS) Using PRELAX the Long-awaited Solution for Treatment of Posthemorrhagic Cerebral Vasospasm? : Treatment of Posthemorrhagic Cerebral Vasospasm with PRESET and PRELAX: Technical Aspects, Efficacy, and Safety Margins in a Case Series

PURPOSE

Recent observational studies have indicated the efficacy of stent retriever devices for the treatment of posthemorrhagic cerebral vasospasm (CVS), both by deployment and on-site withdrawal into the microcatheter (stent angioplasty, SA) and deployment followed by retraction through the target vessel similar to thrombectomy (Stent Retraction to reLieve Arterial Cerebral vaSospasm caused by SAH, Stent-ReLACSS). This article reports the findings with each application of pRESET and pRELAX in the treatment of CVS.

METHODS

We retrospectively enrolled 25 patients with severe CVS following aneurysmal subarachnoid hemorrhage. For the SA group, a stent retriever or a pRELAX was temporarily deployed into a narrow vessel segment and retrieved into the microcatheter after 3 min. For the Stent-ReLACSS group, a pRELAX was temporarily deployed into a narrow vessel and pulled back unfolded into the internal carotid artery. If intra-arterial vasodilators were administered, they were given exclusively after mechanical vasospasmolysis to maximize the effectiveness of the stent treatment.

RESULTS

In this study fifteen patients and 49 vessels were treated with SA. All were technically successful without periprocedural complications; however, 8/15 patients (53.3%) required additional treatment of the CVS. A total of 10 patients and 23 vessel segments were treated with Stent-ReLACSS. All maneuvers were technically successful without periprocedural complications and all vessels showed significant angiographic improvement. No recurrent CVS requiring further endovascular treatment occurred in-hospital, and neither territorial ischemia in the treated vessels nor vascular injury were observed in follow-up angiography.

CONCLUSION

Based on the presented data it appears that Stent-ReLACSS with pRELAX does not pose any additional risks when used to treat CVS and might be superior to SA, especially concerning mid-term and long-term efficacy. The mechanism of action may be an effect on the endothelium rather than mechanical vasodilation. As many patients with CVS are diagnosed too late, prophylactic treatment of high-risk patients (e.g., poor grade, young, female) is potentially viable.

Three Pillars of Recovery After Aneurysmal Subarachnoid Hemorrhage: A Narrative Review

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating neurologic disease with high mortality and disability. There have been global improvements in survival, which has contributed to the prevalence of patients living with long-term sequelae related to this disease. The focus of active research has traditionally centered on acute treatment to reduce mortality, but now there is a great need to study the course of short- and long-term recovery in these patients. In this narrative review, we aim to describe the core pillars in the preservation of cerebral function, prevention of complications, the recent literature studying neuroplasticity, and future directions for research to enhance recovery outcomes following aSAH.

The Impact of Enteral Nimodipine on Endothelial Cell Apoptosis in an Animal Subarachnoid Hemorrhage Model

BACKGROUND

Enteral nimodipine is the most evidence-based and widely used drug for the treatment of delayed cerebral ischemia and is known to have various neuroprotective functions. However, the neuroprotective mechanism of nimodipine still remains unclear, and the effects of nimodipine remain ambiguous. Herein, we studied the effect of enteral nimodipine on endothelial apoptosis after subarachnoid hemorrhage (SAH).

METHODS

SAH was experimentally introduced in white rabbits (n = 42) that were grouped as follows: enteral nimodipine (SAH-nimodipine group, n = 14), a control that received normal saline (SAH-saline group, n = 13), and a control without hemorrhage (control group, n = 15). On the third day after SAH induction, the brain stem, including the vertebrobasilar vascular system, was extracted. The effects of enteral nimodipine were analyzed by group using histopathologic analysis, including immunohistochemical staining of apoptosis-related proteins (Bcl2 [anti-apoptotic] and Bax [pro-apoptotic]).

RESULTS

Cytoplasmic vacuolation of smooth muscle cells was observed in two SAH hemorrhagic groups and was more prominent in the SAH-saline group. Endothelial desquamation was observed only in the SAH-saline group. For the basilar artery, expression of Bcl2 and Bax in the SAH-nimodipine group was lower than that in the SAH-saline group, but significant differences were not observed (pBcl2 = 0.311 and pBax = 0.720, respectively). In penetrated arterioles, the expression of Bax in the SAH-nimodipine group was significantly lower than that of the SAH-saline group (p < 0.001). The thickness of the tunica media in the basilar artery was thinner in the SAH-nimodipine group than in the SAH-saline group (p < 0.001).

CONCLUSIONS

This study suggests that enteral nimodipine may have a neuroprotective function by inhibiting endothelial apoptosis in small arterioles and preventing smooth muscle cell proliferation in large arteries.

Catheter-associated urinary tract infection (CAUTI) reduction in a neuroscience intensive care unit: A multidisciplinary approach

Utilizing a multidisciplinary approach to identify catheter-associated urinary tract infection (CAUTI) risks in Neuroscience intensive care patients admitted for aneurysmal subarachnoid hemorrhage, our CAUTI rate decreased from 5.903 per 1,000 catheter days (June 2020-June 2021) to 0.371 per 1,000 catheter days in our postintervention time period (July 2021-March 2023). A review of our clinical treatment guideline to optimize the timing of indwelling urinary catheters and medication management related to bowel regimens has resulted in a sustained CAUTI reduction, particularly in postaneurysmal subarachnoid hemorrhage patients in the Neuroscience intensive care unit.

Effectiveness of Cerebrospinal Fluid Lumbar Drainage Among Patients with Aneurysmal Subarachnoid Hemorrhage: An Updated Systematic Review and Meta-Analysis

INTRODUCTION

Cerebral vasospasm in patients after aneurysmal subarachnoid hemorrhage (aSAH) continues to be a major source of morbidity despite significant clinical and basic science research. The removal of blood and its degradation products from the subarachnoid space through prophylactic lumbar drainage (LD) is a favorable option. However, several studies have delivered conflicting conclusions on its efficacy after aSAH.

METHODS

Systematic searches of Medline, Embase, and Cochrane Central Register of Controlled Trials were performed. The primary outcome was a good functional outcome (modified Rankin scale score, 0-2). Secondary outcomes included symptomatic vasospasm, secondary cerebral infarction, and mortality.

RESULTS

A total of 14 studies reporting on 2473 patients with aSAH were included in the meta-analysis. Compared with the non-LD group, no significant differences were found in the rates of good functional outcomes in the LD group at discharge to 1 month (risk ratio [RR], 1.28; 95% confidence interval [CI], 0.64-2.58) or at 6 months (RR, 1.12; 95% CI, 0.97-1.41). These findings were consistent in the subgroup analyses of only randomized controlled trials or observational studies. LD was associated with lower rates of symptomatic vasospasm (RR, 0.61; 95% CI, 0.48-0.77), secondary cerebral infarction (RR, 0.59; 95% CI, 0.45-0.79), and mortality at discharge to 1 month (RR, 0.58; 95% CI, 0.41-0.82). The effect on mortality diminished at 6 months (RR, 0.70; 95% CI, 0.34-1.45). However, when analyzing only randomized controlled trials, the benefit of LD on lower rates of mortality continued even at 6 months (RR, 0.75; 95% CI, 0.58-0.99).

CONCLUSIONS

For aSAH patients, the use of LD is associated with benefits in the rates of vasospasm, secondary cerebral infarctions, and mortality, without an increased risk of adverse events.

Diagnosis and management of subarachnoid haemorrhage

Aneurysmal subarachnoid haemorrhage (aSAH) presents a challenge to clinicians because of its multisystem effects. Advancements in computed tomography (CT), endovascular treatments, and neurocritical care have contributed to declining mortality rates. The critical care of aSAH prioritises cerebral perfusion, early aneurysm securement, and the prevention of secondary brain injury and systemic complications. Early interventions to mitigate cardiopulmonary complications, dyselectrolytemia and treatment of culprit aneurysm require a multidisciplinary approach. Standardised neurological assessments, transcranial doppler (TCD), and advanced imaging, along with hypertensive and invasive therapies, are vital in reducing delayed cerebral ischemia and poor outcomes. Health care disparities, particularly in the resource allocation for SAH treatment, affect outcomes significantly, with telemedicine and novel technologies proposed to address this health inequalities. This article underscores the necessity for comprehensive multidisciplinary care and the urgent need for large-scale studies to validate standardised treatment protocols for improved SAH outcomes.

Intra-arterial nimodipine for the treatment of refractory delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is one of the main contributors to poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH). Endovascular spasmolysis with intra-arterial nimodipine (IAN) may resolve angiographic vasospasm, but its effect on infarct prevention and clinical outcome is still unclear. We report the effect of IAN on infarction rates and functional outcome in a consecutive series of SAH patients.

METHODS

To assess the effectiveness of IAN, we collected functional outcome data of all SAH patients referred to a single tertiary center since its availability (2011-2020). IAN was primarily reserved as a last tier option for DCI refractory to induced hypertension (iHTN). Functional outcome was assessed after 12 months according to the Glasgow Outcome Scale (GOS, favorable outcome = GOS4-5).

RESULTS

Out of 376 consecutive SAH patients, 186 (49.5%) developed DCI. Thereof, a total of 96 (25.5%) patients remained unresponsive to iHTN and received IAN. DCI-related infarction was observed in 44 (45.8%) of IAN-treated patients with a median infarct volume of 111.6 mL (Q1: 51.6 to Q3: 245.7). Clinical outcome was available for 84 IAN-treated patients. Of those, a total of 40 (47.6%) patients reached a favorable outcome after 1 year. Interventional complications were observed in 9 (9.4%) of the IAN-treated patients.

CONCLUSION

Intra-arterial spasmolysis using nimodipine infusion was associated with low treatment specific complications. Despite presenting a subgroup of severely affected SAH patients, almost half of IAN-treated patients were able to lead an independent life after 1 year of follow-up.

TRIAL REGISTRATION NUMBER

German Clinical Trial Register DRKS00030505.

Switching Off Vascular MAPK Signaling: A Novel Strategy to Prevent Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage

Patients who initially survive the rupture and repair of a brain aneurysm often take a devastating turn for the worse some days later and die or suffer permanent neurologic deficits. This catastrophic sequela is attributed to a delayed phase of global cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH), but we lack effective treatment. Here we present our view, based on 20 years of research, that the initial drop in blood flow at the time of rupture triggers genomic responses throughout the brain vasculature that manifest days later as increased vasoconstriction and decreased cerebral blood flow. We propose a novel treatment strategy to prevent DCI by early inhibition of the vascular mitogen-activated protein kinase (MAPK) pathway that triggers expression of vasoconstrictor and inflammatory mediators. We summarize evidence from experimental SAH models showing early treatment with MAPK inhibitors "switches off" these detrimental responses, maintains flow, and improves neurological outcome. This promising therapy is currently being evaluated in clinical trials.

Twelve controversial questions in aneurysmal subarachnoid hemorrhage

Critical care management of aneurysmal subarachnoid hemorrhage (aSAH) remains a major challenge. Despite the recent publication of guidelines from the American Heart Association/American Stroke Association and the Neurocritical Care Society, there are many controversial questions in the intensive care unit (ICU) management of this population. The authors provide an analysis of common issues in the ICU and provide guidance on the daily management of this specific population of neurocritical care patients.

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.

The Cell Permeant Phosphopetpide mimetic of VASP Alleviates Motor Function Deficits After Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) due to the rupture of an intracranial aneurysm leads to delayed vasospasm and neuroischemia, which can result in profound neurologic deficit and death. Therapeutic options after SAH are currently limited to hemodynamic optimization and nimodipine, which have limited clinical efficacy. Experimental SAH results in cerebral vasospasm have demonstrated the downregulation of nitric oxide (NO)-protein kinase G (PKG) signaling elements. VP3 is a novel cell permeant phosphopeptide mimetic of VASP, a substrate of PKG and an actin-associated protein that modulates vasorelaxation in vascular smooth muscle cells. In this study, we determined that intravenous administration of high doses of VP3 did not induce systemic hypotension in rats except at the maximal soluble dose, implying that VP3 is well-tolerated and has a wide therapeutic window. Using a single cisterna magna injection rat model of SAH, we demonstrated that intravenous administration of low-dose VP3 after SAH improved neurologic deficits for up to 14 days as determined by the rotarod test. These findings suggest that strategies aimed at targeting the cerebral vasculature with VP3 may improve neurologic deficits associated with SAH.

Advances in targeting Phosphodiesterase 1: From mechanisms to potential therapeutics

Phosphodiesterase 1 (PDE1) is an enzyme entrusted with the hydrolysis of the second messengers cAMP and cGMP, thereby governing a plethora of metabolic processes, encompassing ion channel modulation and cellular apoptosis. Recent advancements in the realm of small molecule structural variations have greatly facilitated the exploration of innovative applications for PDE1. Remarkably, a recent series of PDE1 inhibitors (PDE1i) have been meticulously formulated and devised, showcasing enhanced selectivity and potency. Among them, ITI-214 has entered Phase II clinical trials, holding promise for the treatment of Parkinson's disease and heart failure. Nevertheless, the majority of current PDE1 inhibitors have encountered substantial side effects in clinical trials attributable to their limited selectivity, this predicament presents a formidable obstacle in the development of specific small molecule inhibitors targeting PDE1. This Perspective endeavors to illuminate the potential design approaches, structure-activity relationships, and biological activities of current PDE1i, aiming to offer support and insights for clinical practice and the development of novel PDE1i.

Nimodipine systemic exposure and outcomes following aneurysmal subarachnoid hemorrhage: a pilot prospective observational study (ASH-1 study)

Background

Nimodipine improves outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Guidelines recommend that all patients should receive a fixed-dose nimodipine for 21 days. However, studies reported variability of nimodipine concentrations in aSAH. It is not clear if reduced systemic exposure contributes to worsening outcomes. The aim of this study was to compare nimodipine systemic exposure in those who experienced poor outcomes to those who experienced favorable outcomes.

Methods

This was a pilot prospective observational study in 30 adult patients admitted to the University of Alberta Hospital with aSAH. Data were collected from the electronic health records following enrollment. Blood samples were collected around one nimodipine 60 mg dose at a steady state, and nimodipine [total, (+)-R and (-)-S enantiomers] plasma concentrations were determined. The poor outcome was defined as a modified Rankin Scale (mRS) score at 90 days of 3-6, while the favorable outcome was an mRS score of 0-2. The correlation between nimodipine concentrations and percent changes in mean arterial pressure (MAP) before and after nimodipine administration was also determined. Furthermore, covariates potentially associated with nimodipine exposure were explored.

Results

In total, 20 (69%) participants had favorable outcomes and 9 (31%) had poor outcomes. Following the exclusion of those with delayed presentation (>96 h from aSAH onset), among those presented with the World Federation of Neurological Surgeons (WFNS) grade 3-5, nimodipine median (interquartile range) area under the concentration time curve (AUC0-3h) in those with favorable outcomes were 4-fold higher than in those with poor outcomes [136 (52-192) vs. 33 (23-39) ng.h/mL, respectively, value of p = 0.2]. On the other hand, among those presented with WFNS grade 1-2, nimodipine AUC0-3h in those with favorable outcomes were significantly lower than in those with poor outcomes [30 (28-36) vs. 172 (117-308) ng.h/mL, respectively, value of p = 0.03)]. (+)-R-nimodipine AUC0-3h in those who did not develop vasospasm were 4-fold significantly higher than those who had vasospasm (value of p = 0.047). (-)-S-nimodipine was significantly correlated with percentage MAP reduction. Similar results were obtained when the whole cohort was analyzed.

Conclusion

The study was the first to investigate the potential association between nimodipine exposure following oral dosing and outcomes. In addition, it suggests differential effects of nimodipine enantiomers, shedding light on the potential utility of nimodipine enantiomers. Larger studies are needed.

Effect of Intrathecal Urokinase Infusion on Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Vasospasm following an aneurysmal subarachnoid hemorrhage (SAH) causes serious neurological complications, despite surgical clipping of the aneurysm. Intrathecal urokinase (UK) infusion has been shown to effectively prevent symptomatic vasospasm in patients who have undergone endovascular obliteration of the ruptured aneurysms.

OBJECTIVE

To investigate whether intrathecal UK infusion can prevent symptomatic vasospasm in patients undergoing surgical or endovascular treatment.

METHODS

A total of 90 patients with severe aneurysmal SAH were enrolled and assigned to a surgical neck clipping (n = 56) or an endovascular coil embolization (n = 34) groups. After treatment, UK infusion from the lumbar drain was repeated in 32 patients in the surgical neck clipping group (group B) and all in the endovascular coil embolization group (group C) until complete resolution of the SAH was observed on computed tomography. The remaining 24 of the surgical neck clipping group, without UK infusion, were assigned to group A.

RESULTS

Symptomatic vasospasm occurred in 7 (29.2%) patients in group A, 2 (6.3%) in group B, and none in group C (group A vs. group B [P = 0.02]; group B vs. group C [P = 0.14]). Excellent clinical outcomes (modified Rankin score, 0 or 1) were observed in 37.5%, 59.4%, and 76.5% of patients in group A, B, and C, respectively (group A vs. group B [P = 0.11]).

CONCLUSION

Clearance of SAH via intrathecal UK infusion significantly reduced symptomatic vasospasm in patients in both UK groups, resulting in better clinical outcomes.

Management of neurological complications related to aneurysmal subarachnoid hemorrhage: A comparison of the bedside therapeutic algorithms

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is of the most serious emergencies in neurosurgical practice and continues to be associated with high morbidity and mortality. Beyond securing the ruptured aneurysm to prevent a rebleed, physicians continue to be concerned about potential complications such as cerebral vasospasm-delayed cerebral ischemia (DCI), an area where management remains highly variable. This study aimed at reviewing the most recent literature and assessing any up-to-date schemes for treating the most common aSAH neurological complications in adults that can be applied in daily clinical practice towards optimising outcomes.

METHODS

A systematic review was performed according to PRISMA guidelines on the management of aSAH neurological complications in adults. The literature surveyed was between 2016 and 2022 inclusive, using the Pubmed search engine. Comparisons between the methods suggested by existing therapeutic algorithms were discussed.

RESULTS

Six stepwise algorithms assisting the decision-making for treating cerebral vasospasm-DCI were recognised and compared. No algorithm was found for the management of any other neurological complications of aSAH. Despite differences in the algorithms, induced hypertension and endovascular therapy were common treatments in all approaches. Controversy in the therapeutic process of these complications surrounds not only the variability of methods but also their optimal application towards clinical outcome optimisation.

CONCLUSIONS

A universal approach to managing aSAH complications is lacking. Despite advances in the techniques to secure a ruptured aneurysm, there persist a high rate of neurological deficit and mortality, and several unanswered questions. More research is required towards stratification of current treatment algorithms as per the quality of their evidence.

Animal Welfare Aspects in Planning and Conducting Experiments on Rodent Models of Subarachnoid Hemorrhage

Subarachnoid hemorrhage is an acute life-threatening cerebrovascular disease with high socio-economic impact. The most frequent cause, the rupture of an intracerebral aneurysm, is accompanied by abrupt changes in intracerebral pressure, cerebral perfusion pressure and, consequently, cerebral blood flow. As aneurysms rupture spontaneously, monitoring of these parameters in patients is only possible with a time delay, upon hospitalization. To study alterations in cerebral perfusion immediately upon ictus, animal models are mandatory. This article addresses the points necessarily to be included in an animal project proposal according to EU directive 2010/63/EU for the protection of animals used for scientific purposes and herewith offers an insight into animal welfare aspects of using rodent models for the investigation of cerebral perfusion after subarachnoid hemorrhage. It compares surgeries, model characteristics, advantages, and drawbacks of the most-frequently used rodent models-the endovascular perforation model and the prechiasmatic and single or double cisterna magna injection model. The topics of discussing anesthesia, advice on peri- and postanesthetic handling of animals, assessing the severity of suffering the animals undergo during the procedure according to EU directive 2010/63/EU and weighing the use of these in vivo models for experimental research ethically are also presented. In conclusion, rodent models of subarachnoid hemorrhage display pathophysiological characteristics, including changes of cerebral perfusion similar to the clinical situation, rendering the models suited to study the sequelae of the bleeding. A current problem is low standardization of the models, wherefore reporting according to the ARRIVE guidelines is highly recommended. Animal welfare aspects of rodent models of subarachnoid hemorrhage. Rodent models for investigation of cerebral perfusion after subarachnoid hemorrhage are compared regarding surgeries and model characteristics, and 3R measures are suggested. Anesthesia is discussed, and advice given on peri- and postanesthetic handling. Severity of suffering according to 2010/63/EU is assessed and use of these in vivo models weighed ethically.

The Evolution and Future of Intensive Care Management in the Era of Telecritical Care and Artificial Intelligence

Critical care practice has been embodied in the healthcare system since the institutionalization of intensive care units (ICUs) in the late '50s. Over time, this sector has experienced many changes and improvements in providing immediate and dedicated healthcare as patients requiring intensive care are often frail and critically ill with high mortality and morbidity rates. These changes were aided by innovations in diagnostic, therapeutic, and monitoring technologies, as well as the implementation of evidence-based guidelines and organizational structures within the ICU. In this review, we examine these changes in intensive care management over the past 40 years and their impact on the quality of care available to patients. Moreover, the current state of intensive care management is characterized by a multidisciplinary approach and the use of innovative technologies and research databases. Advancements such as telecritical care and artificial intelligence are being increasingly explored, especially since the COVID-19 pandemic, to reduce the length of hospitalization and ICU mortality. With these advancements in intensive care and ever-changing patient needs, critical care experts, hospital managers, and policymakers must also explore appropriate organizational structures and future enhancements within the ICU.

Management of hypertensive crisis: British and Irish Hypertension Society Position document

Patients with hypertensive emergencies, malignant hypertension and acute severe hypertension are managed heterogeneously in clinical practice. Initiating anti-hypertensive therapy and setting BP goal in acute settings requires important considerations which differ slightly across various diagnoses and clinical contexts. This position paper by British and Irish Hypertension Society, aims to provide clinicians a framework for diagnosing, evaluating, and managing patients with hypertensive crisis, based on the critical appraisal of available evidence and expert opinion.

The efficacy of different nimodipine administration route for treating subarachnoid hemorrhage: A network meta-analysis

BACKGROUND

A systematic review and network meta-analysis (NMA) were conducted to explore the optimal administration route of nimodipine for treatment subarachnoid hemorrhage.

METHODS

Electronic databases (Pubmed, Embase, Web of Science and Cochrane databases) were systematically searched to identify randomized controlled trials evaluating different administration route of nimodipine (intravenous and enteral) versus placebo for treatment subarachnoid hemorrhage. Outcomes included case fatality at 3 months, poor outcome measured at 3 months (defined as death, vegetative state, or severe disability), incidence of delayed cerebral ischemia (DCI), delayed ischemic neurological deficit. A random-effect Bayesian NMA was conducted for outcomes of interest, and results were presented as odds ratios (ORs) and 95% credible intervals. The NMA was performed using R Software with a GeMTC package. A Bayesian NMA was performed and relative ranking of agents was assessed using surface under the cumulative ranking (SUCRA) probabilities.

RESULTS

Nine randomized controlled trials met criteria for inclusion and finally included in this NMA. There was no statistically significant between intravenous and enteral in terms of case fatality, the occurrence of DCI, delayed ischemic neurologic deficit and poor outcomes (P > .05). Both intravenous and enteral could reduce case fatality, the occurrence of DCI, delayed ischemic neurologic deficit and poor outcomes (P < .05). The SUCRA shows that enteral ranked first, intravenous ranked second and placebo ranked the last for case fatality, the occurrence of DCI and poor outcomes. The SUCRA shows that intravenous ranked first, enteral ranked second and placebo ranked the last for delayed ischemic neurologic deficit.

CONCLUSIONS

It is possible that both enteral and intravenous nimodipine have comparable effectiveness in preventing poor outcomes, DCI, and delayed ischemic neurological deficits. However, further investigation may be necessary to determine the exact role of intravenous nimodipine in current clinical practice.

A randomized, single ascending dose safety, tolerability and pharmacokinetics study of NicaPlant® in aneurysmal subarachnoid hemorrhage patients undergoing clipping

Introduction

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality. Post-hemorrhagic vasospasm with neurological deterioration is a major concern in this context. NicaPlant®, a modified release formulation of the calcium channel blocker nicardipine, has shown vasodilator efficacy preclinically and a similar formulation known as NPRI has shown anti-vasospasm activity in aSAH patients under compassionate use.

Research question

The study aimed to assess pharmacokinetics and pharmacodynamics of NicaPlant® pellets to prevent vasospasm after clip ligation in aSAH.

Material and methods

In this multicenter, controlled, randomized, dose escalation trial we assessed the safety and tolerability of NicaPlant®. aSAH patients treated by clipping were randomized to receive up to 13 NicaPlant® implants, similarly to the dose of NPRIs previous used, or standard of care treatment.

Results

Ten patients across four dose groups were treated with NicaPlant® (3-13 implants) while four patients received standard of care. 45 non-serious and 13 serious adverse events were reported, 4 non-serious adverse events and 5 serious adverse events assessed a probable or possible causal relationship to the investigational medical product. Across the NicaPlant® groups there was 1 case of moderate vasospasm, while in the standard of care group there were 2 cases of severe vasospasm.

Discussion and conclusion

The placement of NicaPlant® during clip ligation of a ruptured cerebral aneurysm raised no safety concern. The dose of 10 NicaPlant® implants was selected for further clinical studies.

Antiplatelet therapy in aneurysmal subarachnoid hemorrhage: an updated meta-analysis

Antiplatelet therapy (AT) may serve to reduce the effects of aneurysmal subarachnoid hemorrhage (aSAH)-induced pro-coagulant state in the cerebral circulation. Several studies, however, have delivered conflicting conclusions on the efficacy of AT post aSAH. Systematic searches of Medline, Embase, and Cochrane Central were undertaken on 27th March 2023. The primary outcome was delayed cerebral ischaemia (DCI). Secondary outcomes were symptomatic and angiographic vasospasm, good functional outcome (modified Rankin Scale [mRS] with scores 0-2), hemorrhagic events, and in-hospital mortality. Twenty-two studies reporting 4378 patients with aSAH were included in the meta-analysis. AT was associated with lower rates of DCI (RR=0.62, 95% CI: 0.43; 0.89), symptomatic vasospasm (RR=0.63, 95% CI: 0.46; 0.86), and moderate/severe angiographic vasospasm (RR=0.74, 95% CI: 0.65; 0.84), with no effect on hemorrhagic complications (RR=1.36, 95% CI: 0.77; 2.41). When analyzing only post-ictal use of AT, AT additionally favored rates of good functional outcomes (RR=1.18, 95% CI: 1.10; 1.26) and in-hospital mortality (RR=0.56, 95% CI: 0.39; 0.80). In the subgroup treated with cilostazol, AT was associated with lower rates of DCI (RR=0.40, 95% CI: 0.32), symptomatic vasospasm (RR=0.47, 95% CI: 0.33; 0.65), moderate/severe angiographic vasospasm (RR=0.75, 95% CI: 0.57; 0.98) and good functional outcome (RR=1.24, 95% CI: 1.08; 1.43). In the surgically treated aSAH subgroup, AT favored rates of symptomatic vasospasm (RR=0.55, 95% CI: 0.30; 0.98), moderate/severe angiographic vasospasm (RR=0.70, 95% CI: 0.54; 0.90) and good functional outcome (RR=1.23, 95% CI: 1.09; 1.41). In the endovascularly treated aSAH subgroup, AT was associated with lower rates of in-hospital mortality (RR=0.60, 95% CI: 0.41; 0.88). In aSAH patients, post-ictal AT is associated with benefits in terms of rates of DCI, vasospasm, good functional outcomes, and in-hospital mortality without an increased risk of hemorrhagic events.

COManeci MechANical Dilation for vasospasm (COMMAND): multicenter experience

BACKGROUND

We report the largest multicenter experience to date of utilizing the Comaneci device for endovascular treatment of refractory intracranial vasospasm.

METHODS

Consecutive patients undergoing Comaneci mechanical dilatation for vasospasm were extracted from prospectively maintained registries in 11 North American centers (2020-2022). Intra-arterial vasodilators (IAV) were allowed, with the Comaneci device utilized after absence of vessel dilation post-infusion. Pre- and post-vasospasm treatment scores were recorded for each segment, with primary radiological outcome of score improvement post-treatment. Primary clinical outcome was safety/device-related complications, with secondary endpoints of functional outcomes at last follow-up.

RESULTS

A total of 129 vessels in 40 patients (median age 52 years; 67.5% females) received mechanical dilation, 109 of which (84.5%) exhibited pre-treatment severe-to-critical vasospasm (ie, score 3/4). Aneurysmal subarachnoid hemorrhage was the most common etiology of vasospasm (85%), with 65% of procedures utilizing Comaneci-17 (92.5% of patients received IAV). The most treated segments were anterior cerebral artery (34.9%) and middle cerebral artery (31%). Significant vasospasm drop (pre-treatment score (3-4) to post-treatment (0-2)) was achieved in 89.9% of vessels (96.1% of vessels experienced ≥1-point drop in score post-treatment). There were no major procedural/post-procedural device-related complications. Primary failure (ie, vessel unresponsive) was encountered in one vessel (1 patient) (1/129; 0.8%) while secondary failure (ie, recurrence in previously treated segment requiring retreatment in another procedure) occurred in 16 vessels (7 patients) (16/129; 12.4%), with median time-to-retreatment of 2 days. Favorable clinical outcome (modified Rankin Scale 0-2) was noted in 51.5% of patients (median follow-up 6 months).

CONCLUSIONS

The Comaneci device provides a complementary strategy for treatment of refractory vasospasm with reasonable efficacy/favorable safety. Future prospective trials are warranted.

Synthesis of 4-Alkylated 1,4-Dihydropyridines: Fe(II)-Mediated Oxidative Cascade Cyclization Reaction of Cyclic Ethers with Enaminones

Syntheses of highly functionalized 4-alkylated 1,4-dihydropyridines (1,4-DHPs) from cyclic ethers and enaminones via iron(II)-mediated oxidative free radical cascade C(sp3)-H bond functionalization/C(sp3)-O bond cleavage/cyclization reaction have been first developed. This novel synthetic strategy offers an alternative method for the construction of 1,4-DHPs by using esters as the C4 sources, as well as expands the application of ethers in heterocycle synthesis.

A network meta-analysis of therapeutic and prophylactic management of vasospasm on aneurysmal subarachnoid hemorrhage outcomes

Background

Vasospasm and cerebral ischemia after aneurysmal subarachnoid hemorrhage are associated with mortality and poor neurological outcomes. We studied the efficacy of all available strategies targeting vasospasm and cerebral ischemia on outcomes in a network meta-analysis.

Methods

We searched EMBASE and MEDLINE databases from 1 January 1990 and 28 November 2021 according to PRISMA guidelines. Randomized controlled trials and longitudinal studies were included. All curative or preventive strategies targeting vasospasm and/or cerebral ischemia were eligible. A network meta-analysis was performed to compare all interventions with one another in a primary (randomized controlled trials only) and a secondary analysis (both trials and longitudinal studies). Mortality by 3 months was the primary outcome. Secondary outcomes were vasospasm, neurological outcome by 3 months, and dichotomized as "good" or "poor" recovery according to each study definition.

Results

A total of 2,382 studies were screened which resulted in the selection of 192 clinical trials (92 (47.9%) and 100 cohorts (52.1%) and the inclusion of 41,299 patients. In randomized controlled studies, no strategy decreased mortality by 3 months. Statins (0.79 [0.62-1]), tirilazad (0.82 [0.69-0.97]), CSF drainage (0.47 [0.29-0.77]), and clazosentan (0.51 [0.36-0.71]) significantly decreased the incidence of vasospasm. Cilostazol was the only treatment associated with improved neurological outcomes by 3 months in the primary (OR 1.16, 95% CI [1.05-1.28]) and secondary analyses (OR 2.97, 95% CI [1.39-6.32]).

Discussion

In the modern era of subarachnoid hemorrhage, all strategies targeting vasospasm failed to decrease mortality. Cilostazol should be confirmed as a treatment to improve neurological outcomes. The link between vasospasm and neurological outcome appears questionable.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=116073, identifier: PROSPERO CRD42018116073.

Guidelines for the Neurocritical Care Management of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The neurointensive care management of patients with aneurysmal subarachnoid hemorrhage (aSAH) is one of the most critical components contributing to short-term and long-term patient outcomes. Previous recommendations for the medical management of aSAH comprehensively summarized the evidence based on consensus conference held in 2011. In this report, we provide updated recommendations based on appraisal of the literature using the Grading of Recommendations Assessment, Development, and Evaluation methodology.

METHODS

The Population/Intervention/Comparator/Outcome (PICO) questions relevant to the medical management of aSAH were prioritized by consensus from the panel members. The panel used a custom-designed survey instrument to prioritize clinically relevant outcomes specific to each PICO question. To be included, the study design qualifying criteria were as follows: prospective randomized controlled trials (RCTs), prospective or retrospective observational studies, case-control studies, case series with a sample larger than 20 patients, meta-analyses, restricted to human study participants. Panel members first screened titles and abstracts, and subsequently full text review of selected reports. Data were abstracted in duplicate from reports meeting inclusion criteria. Panelists used the Grading of Recommendations Assessment, Development, and Evaluation Risk of Bias tool for assessment of RCTs and the "Risk of Bias In Nonrandomized Studies - of Interventions" tool for assessment of observational studies. The summary of the evidence for each PICO was presented to the full panel, and then the panel voted on the recommendations.

RESULTS

The initial search retrieved 15,107 unique publications, and 74 were included for data abstraction. Several RCTs were conducted to test pharmacological interventions, and we found that the quality of evidence for nonpharmacological questions was consistently poor. Five PICO questions were supported by strong recommendations, one PICO question was supported by conditional recommendations, and six PICO questions did not have sufficient evidence to provide a recommendation.

CONCLUSIONS

These guidelines provide recommendations for or against interventions proven to be effective, ineffective, or harmful in the medical management of patients with aSAH based on a rigorous review of the available literature. They also serve to highlight gaps in knowledge that should guide future research priorities. Despite improvements in the outcomes of patients with aSAH over time, many important clinical questions remain unanswered.

Blood Pressure Changes in Association with Nimodipine Therapy in Patients with Spontaneous Subarachnoid Hemorrhage

BACKGROUND

Nimodipine is recommended to prevent delayed cerebral ischemia in patients with spontaneous subarachnoid hemorrhage (SAH). Here, we studied hemodynamic side effects of different nimodipine formulations (per os [PO] and intravenous [IV]) in patients with SAH undergoing continuous blood pressure monitoring.

METHODS

This observational cohort study includes consecutive patients with SAH (271 included in the IV group, 49 in the PO group) admitted to a tertiary care center between 2010 and 2021. All patients received prophylactic IV or PO nimodipine. Hemodynamic responses were evaluated based on median values within the first hour after continuous IV nimodipine initiation or PO nimodipine application (601 intakes within 15 days). Significant changes were defined as > 10% drop in systolic blood pressure (SBP) or diastolic blood pressure from baseline (median values 30 min before nimodipine application). With the use of multivariable logistic regression, risk factors associated with SBP drops were identified.

RESULTS

Patients were admitted with a median Hunt & Hess score of 3 (2-5; IV 3 [2-5], PO 1 [1-2], p < 0.001) and were 58 (49-69) years of age. Initiation of IV nimodipine was associated with a > 10% SBP drop in 30% (81/271) of patients, with a maximum effect after 15 min. A start or increase in noradrenaline was necessary in 136/271 (50%) patients, and colloids were administered in 25/271 (9%) patients within 1 h after IV nimodipine initiation. SBP drops > 10% occurred after 53/601 (9%) PO nimodipine intakes, with a maximum effect after 30-45 min in 28/49 (57%) patients. Noradrenaline application was uncommon (3% before and 4% after nimodipine PO intake). Hypotensive episodes to an SBP < 90 mm Hg were not observed after IV or PO nimodipine application. In multivariable analysis, only a higher SBP at baseline was associated with a > 10% drop in SBP after IV (p < 0.001) or PO (p = 0.001) nimodipine application, after adjusting for the Hunt & Hess score on admission, age, sex, mechanical ventilation, days after intensive care unit admission, and delayed cerebral ischemia.

CONCLUSIONS

Significant drops in SBP occur in one third of patients after the start of IV nimodipine and after every tenth PO intake. Early recognition and counteracting with vasopressors or fluids seems necessary to prevent hypotensive episodes.

The Effect of Oral Nimodipine on Cerebral Metabolism and Hemodynamic Parameters in Patients Suffering Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION

Nimodipine is routinely administered to aneurysmal subarachnoid hemorrhage patients to improve functional outcomes. Nimodipine can induce marked systemic hypotension, which might impair cerebral perfusion and brain metabolism.

METHODS

Twenty-seven aneurysmal subarachnoid hemorrhage patients having multimodality neuromonitoring and oral nimodipine treatment as standard of care were included in this retrospective study. Alterations in mean arterial blood pressure (MAP), cerebral perfusion pressure (CPP), brain tissue oxygen tension (pbtO2), and brain metabolism (cerebral microdialysis), were investigated up to 120 minutes after oral administration of nimodipine (60 mg or 30 mg), using mixed linear models.

RESULTS

Three thousand four hundred twenty-five oral nimodipine administrations were investigated (126±59 administrations/patient). After 60 mg of oral nimodipine, there was an immediate statistically significant (but clinically irrelevant) drop in MAP (relative change, 0.97; P<0.001) and CPP (relative change: 0.97; P<0.001) compared with baseline, which lasted for the whole 120 minutes observation period (P<0.001). Subsequently, pbtO2 significantly decreased 50 minutes after administration (P=0.04) for the rest of the observation period; the maximum decrease was -0.6 mmHg after 100 minutes (P<0.001). None of the investigated cerebral metabolites (glucose, lactate, pyruvate, lactate/pyruvate ratio, glutamate, glycerol) changed after 60 mg nimodipine. Compared with 60 mg nimodipine, 30 mg induced a lower reduction in MAP (relative change, 1.01; P=0.02) and CPP (relative change, 1.01; P=0.03) but had similar effects on pbtO2 and cerebral metabolism (P>0.05).

CONCLUSIONS

Oral nimodipine reduced MAP, which translated into a reduction in cerebral perfusion and oxygenation. However, these changes are unlikely to be clinically relevant, as the absolute changes were minimal and did not impact cerebral metabolism.

The efficacy of antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Aim

The efficacy of antifibrinolytics in subarachnoid hemorrhage remains unclear due to conflicting evidence from studies.

Materials & methods

Online databases were queried to include randomized controlled trials and propensity matched observational studies. We used Review Manager for the statistical analysis, presenting results as odds ratios with 95% CI.

Results

The 12 shortlisted studies included 3359 patients, of which 1550 (46%) were in the intervention (tranexamic acid) group and 1809 (54%) in the control group. Antifibrinolytic therapy significantly reduced the risk of rebleeding (OR: 0.55; 95% CI: 0.40-0.75; p = 0.0002) with no significant decrease in poor clinical outcome (OR: 1.02; 95% CI: 0.86-1.20; p = 0.85) and all-cause mortality (OR: 0.92; CI: 0.72-1.17; p = 0.50).

Conclusion

In patients with subarachnoid hemorrhage, antifibrinolytics reduce the risk of rebleeding without significantly affecting mortality or clinical outcomes.

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage" replaces the 2012 "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage." The 2023 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with aneurysmal subarachnoid hemorrhage.

METHODS

A comprehensive search for literature published since the 2012 guideline, derived from research principally involving human subjects, published in English, and indexed in MEDLINE, PubMed, Cochrane Library, and other selected databases relevant to this guideline, was conducted between March 2022 and June 2022. In addition, the guideline writing group reviewed documents on related subject matter previously published by the American Heart Association. Newer studies published between July 2022 and November 2022 that affected recommendation content, Class of Recommendation, or Level of Evidence were included if appropriate. Structure: Aneurysmal subarachnoid hemorrhage is a significant global public health threat and a severely morbid and often deadly condition. The 2023 aneurysmal subarachnoid hemorrhage guideline provides recommendations based on current evidence for the treatment of these patients. The recommendations present an evidence-based approach to preventing, diagnosing, and managing patients with aneurysmal subarachnoid hemorrhage, with the intent to improve quality of care and align with patients' and their families' and caregivers' interests. Many recommendations from the previous aneurysmal subarachnoid hemorrhage guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Unpacking the Role of Extracellular Vesicles in Ischemic and Hemorrhagic Stroke: Pathophysiology and Therapeutic Implications

Stroke is a leading cause of death and disability worldwide. Inflammation and microvascular dysfunction have been associated with brain injury and long-term disability after both ischemic and hemorrhagic stroke. Recent studies have suggested a potential role of extracellular vesicles (EVs) as a link underlying these pathogenic processes. EVs are cell-derived particles enveloped by a lipid bilayer, containing proteins, lipids, and nucleic acids. From a functional standpoint, EVs can facilitate intercellular communication, including across the blood-brain barrier (BBB). Recent advances in EV research have shown a preferential release of EVs from specific cell types in the context of stroke, some of which were associated with increased neuroinflammation, microvascular dysfunction, and neuronal cytotoxicity while others offered a degree of neuroprotection. However, one historic challenge in the studies of EVs in stroke is the lack of consistent definitions and methods to analyze EVs, only recently updated in the MISEV2018 guidelines. Given limitations and complexity in the treatment of stroke, particularly delivery of therapeutics across the BBB, increasing attention has been paid towards manipulating EVs as one vehicle that can permit targeted therapeutic delivery to the central nervous system. These discoveries point towards a future where a better understanding of EVs will advance our knowledge of stroke-associated mechanisms of cerebral and systemic injury and contribute to the development of novel treatments. Here, we review the role that EVs play in ischemic and hemorrhagic stroke.

Impact of the Voltage-Gated Calcium Channel Antagonist Nimodipine on the Development of Oligodendrocyte Precursor Cells

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). While most of the current treatment strategies focus on immune cell regulation, except for the drug siponimod, there is no therapeutic intervention that primarily aims at neuroprotection and remyelination. Recently, nimodipine showed a beneficial and remyelinating effect in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Nimodipine also positively affected astrocytes, neurons, and mature oligodendrocytes. Here we investigated the effects of nimodipine, an L-type voltage-gated calcium channel antagonist, on the expression profile of myelin genes and proteins in the oligodendrocyte precursor cell (OPC) line Oli-Neu and in primary OPCs. Our data indicate that nimodipine does not have any effect on myelin-related gene and protein expression. Furthermore, nimodipine treatment did not result in any morphological changes in these cells. However, RNA sequencing and bioinformatic analyses identified potential micro (mi)RNA that could support myelination after nimodipine treatment compared to a dimethyl sulfoxide (DMSO) control. Additionally, we treated zebrafish with nimodipine and observed a significant increase in the number of mature oligodendrocytes (* p≤ 0.05). Taken together, nimodipine seems to have different positive effects on OPCs and mature oligodendrocytes.

Dyskinesia as a unique presentation of subarachnoid hemorrhage: a case report

BACKGROUND

Subarachnoid hemorrhage (SAH) is a diagnosis that emergency physicians must have a high index of suspicion for. Many common chief complaints such as headache, nausea, altered mental status, and even syncope may alert clinicians to the possibility of a SAH.

CASE PRESENTATION

The authors present an unusual case of SAH in a patient presenting with acute dyskinesia and altered mental status, which has seldom been documented as the presenting feature of SAH, as well as the diagnostic pitfalls encountered in assessing this patient.

CONCLUSION

Emergency physicians should maintain a high index of suspicion for dangerous pathology in cases without a clear etiology; they should also utilize metacognition to assess their own biases and thought patterns so as to avoid missing critical diagnoses.

Less-invasive subdural electrocorticography for investigation of spreading depolarizations in patients with subarachnoid hemorrhage

Introduction

Wyler-strip electrodes for subdural electrocorticography (ECoG) are the gold standard for continuous bed-side monitoring of pathological cortical network events, such as spreading depolarizations (SD) and electrographic seizures. Recently, SD associated parameters were shown to be (1) a marker of early brain damage after aneurysmal subarachnoid hemorrhage (aSAH), (2) the strongest real-time predictor of delayed cerebral ischemia currently known, and (3) the second strongest predictor of patient outcome at 7 months. The strongest predictor of patient outcome at 7 months was focal brain damage segmented on neuroimaging 2 weeks after the initial hemorrhage, whereas the initial focal brain damage was inferior to the SD variables as a predictor for patient outcome. However, the implantation of Wyler-strip electrodes typically requires either a craniotomy or an enlarged burr hole. Neuromonitoring via an enlarged burr hole has been performed in only about 10% of the total patients monitored.

Methods

In the present pilot study, we investigated the feasibility of ECoG monitoring via a less invasive burrhole approach using a Spencer-type electrode array, which was implanted subdurally rather than in the depth of the parenchyma. Seven aSAH patients requiring extraventricular drainage (EVD) were included. For electrode placement, the burr hole over which the EVD was simultaneously placed, was used in all cases. After electrode implantation, continuous, direct current (DC)/alternating current (AC)-ECoG monitoring was performed at bedside in our Neurointensive Care unit. ECoGs were analyzed following the recommendations of the Co-Operative Studies on Brain Injury Depolarizations (COSBID).

Results

Subdural Spencer-type electrode arrays permitted high-quality ECoG recording. During a cumulative monitoring period of 1,194.5 hours and a median monitoring period of 201.3 (interquartile range: 126.1-209.4) hours per patient, 84 SDs were identified. Numbers of SDs, isoelectric SDs and clustered SDs per recording day, and peak total SD-induced depression duration of a recording day were not significantly different from the previously reported results of the prospective, observational, multicenter, cohort, diagnostic phase III trial, DISCHARGE-1. No adverse events related to electrode implantation were noted.

Discussion

In conclusion, our findings support the safety and feasibility of less-invasive subdural electrode implantation for reliable SD-monitoring.

Evaluation of the synergistic effects of epigallocatechin-3-gallate-loaded PEGylated-PLGA nanoparticles with nimodipine against neuronal injury after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating subtype of stroke with high mortality and morbidity. Although serious side effects might occur, nimodipine, a second-generation 1,4-dihydropyridine calcium channel blocker, is clinically used to improve neurological outcomes after SAH. Recently, (-)-epigallocatechin-3-gallate (EGCG) has been reported to inhibit Ca²⁺ overloading-induced mitochondrial dysfunction, oxidative stress, and neuronal cell death after SAH; however, low bioavailability, instability, and cytotoxicity at a high dose limited the clinical application of EGCG. To overcome these limitations, PEGylated-PLGA EGCG nanoparticles (EGCG-NPs) were constructed to enhance the bioavailability by using the double-emulsion method. Antioxidative activity, cytotoxicity, behavioral, and immunohistochemistry studies were carried out to determine the neuroprotective effectiveness after cotreatment with EGCG-NPs (75 mg/kg/d preconditioning for 7 days before SAH) and nimodipine (10 mg/kg/d after 30 min of SAH) by using in vivo SAH models. The optimized EGCG-NPs with a Box-Behnken design showed a small particle size of 167 nm, a zeta potential value of -22.6 mV, an encapsulation efficiency of 86%, and a sustained-release profile up to 8 days in vitro. Furthermore, EGCG-NPs (75 mg/kg/d) had superior antioxidative activity to free EGCG (100 mg/kg/d). EGCG-NPs combined with nimodipine exhibited significant synergistic effects against neuronal cell death by suppressing oxidative stress, Ca²⁺ overloading, mitochondrial dysfunction, and autophagy after SAH. These results suggest that cotreatment with EGCG-NPs and nimodipine may serve as a promising novel strategy for the treatment of SAH.

Clinicians' preferences for managing aneurysmal subarachnoid hemorrhage using endothelin receptor antagonists

Background

The endothelin receptor antagonist (ERA) clazosentan is being investigated for the medical prevention of cerebral vasospasm and associated complications, such as delayed cerebral ischemia (DCI), after aneurysmal subarachnoid hemorrhage (aSAH). This study quantified how clinicians weigh the benefits and risks of ERAs for DCI prevention to better understand their treatment needs and expectations.

Methods

An online choice experiment was conducted to elicit preferences of neurologists, intensivists, and neurosurgeons treating aSAH in the US and UK for the use of ERAs. The design of the choice experiment was informed by a feasibility assessment (N = 100), one-on-one interviews with clinicians (N = 10), a qualitative pilot (N = 13), and a quantitative pilot (N = 50). Selected treatment attributes included in the choice experiment were: one benefit (likelihood of DCI); and three risks (lung complications, hypotension, and anemia). In the choice experiment, clinicians repeatedly chose best and worst treatment options based on a scenario of a patient being treated in the ICU after aneurism repair. A correlated mixed logit model determined the relative attribute importance (RAI) and associated highest density interval (HDI) as well as acceptable benefit-risk trade-offs.

Results

The final choice experiment was completed by 350 clinicians (116 neurologists, 129 intensivists/intensive care clinicians, and 105 neurosurgeons; mean age, 47.4 years). Reducing the likelihood of DCI (RAI = 56.5% [HDI, 53.6-59.5%]) had the largest impact on clinicians' treatment choices, followed by avoiding the risks of lung complications (RAI = 29.6% [HDI, 27.1-32.3%]), hypotension (RAI = 9.2% [HDI, 7.5-10.8%]), and anemia (RAI = 4.7% [HDI, 3.7-5.8%]). Clinicians expected the likelihood of DCI to decrease by ≥8.1% for a 20% increase in the risk of lung complications, ≥2.4% for a 20% increase in the risk of hypotension, and ≥1.2% for a 20% increase in the risk of anemia.

Conclusions

Clinicians were willing to accept certain increased risks of adverse events for a reduced risk of DCI after aSAH. The likelihood of DCI occurring after aSAH can therefore be considered a clinically relevant endpoint in aSAH treatment development. Thus, evaluations of ERAs might focus on whether improvements (i.e., reductions) in the likelihood of DCI justify the risks of adverse events.

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).

A Review of Genetic Polymorphisms and Susceptibilities to Complications after Aneurysmal Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) and vasospasm are two complications of subarachnoid hemorrhages (SAHs) which entail high risks of morbidity and mortality. However, it is unknown why only some patients who suffer SAHs will experience DCI and vasospasm. The purpose of this review is to describe the main genetic single nucleotide polymorphisms (SNPs) that have demonstrated a relationship with these complications. The SNP of the nitric oxide endothelial synthase (eNOS) has been related to the size and rupture of an aneurysm, as well as to DCI, vasospasm, and poor neurological outcome. The SNPs responsible for the asymmetric dimetilarginine and the high-mobility group box 1 have also been associated with DCI. An association between vasospasm and the SNPs of the eNOS, the haptoglobin, and the endothelin-1 receptor has been found. The SNPs of the angiotensin-converting enzyme have been related to DCI and poor neurological outcome. Studies on the SNPs of the Ryanodine Receptor yielded varying results regarding their association with vasospasm.

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.

Serum Levels of Myo-inositol Predicts Clinical Outcome 1 Year After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Early prognostication of long-term outcome in patients suffering from spontaneous subarachnoid hemorrhage (SAH) remains a challenge. No biomarkers are routinely used for prognostication. A previous study has indicated that the metabolite myo-inositol (MI) may be used to predict long-term outcome.

OBJECTIVE

To investigate if MI measured in serum correlates with long-term clinical outcome in patients suffering from SAH.

METHODS

We conducted an observational cohort study including 88 patients treated for SAH at Umeå University Hospital. Serum samples were collected in the hospital, and a gas chromatography/mass spectroscopy method was used to quantitatively measure MI. Patients were assessed after 1 year using the Glasgow Outcome Scale Extended and dichotomized to favorable or unfavorable outcome. Differences in MI levels between the 2 groups were analyzed.

RESULTS

There was no difference in MI levels between the groups upon admission. Myo-inositol levels decreased over time in the entire study population. The decrease was significantly larger in the unfavorable outcome group. A receiver operating characteristics analysis yielded an area under the curve of 0.903 (CI 0.8-1.0, P < .001) for the MI value on day 7 to predict favorable outcome after 1 year.

CONCLUSION

Myo-inositol measured in serum may aid prognostication of outcome in patients with SAH. The mechanism behind this remains unclear, although it can be theorized to reflect processes leading to delayed cerebral ischemia, which affects long-term outcome. This is the first study to quantitively measure MI in serum for prognostication of outcome in patients with SAH.