Feasibility of intraventricular nicardipine prolonged release implants in patients following aneurysmal subarachnoid haemorrhage

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.

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.

Update on intrathecal management of cerebral vasospasm: a systematic review and meta-analysis

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) accounts for a relatively small portion of strokes but has the potential to cause permanent neurological deficits. Vasospasm with delayed ischemic neurological deficit is thought to be responsible for much of the morbidity associated with aSAH. This has illuminated some treatment options that have the potential to target specific components of the vasospasm cascade. Intrathecal management via lumbar drain (LD) or external ventricular drain (EVD) offers unique advantages in this patient population. The aim of this review was to provide an update on intrathecal vasospasm treatments, emphasizing the need for larger-scale trials and updated protocols using data-driven evidence.

METHODS

A search of PubMed, Ovid MEDLINE, and Cochrane databases included the search terms (subarachnoid hemorrhage) AND (vasospasm OR delayed cerebral ischemia) AND (intrathecal OR intraventricular OR lumbar drain OR lumbar catheter) for 2010 to the present. Next, a meta-analysis was performed of select therapeutic regimens. The primary endpoints of analysis were vasospasm, delayed cerebral ischemia (DCI), cerebral infarction, and functional outcome.

RESULTS

Twenty-nine studies were included in the analysis. There were 10 studies in which CSF drainage was the primary experimental group. Calcium channel antagonists were the focus of 7 studies. Fibrinolytics and other vasodilators were each examined in 6 studies. The meta-analysis included studies examining CSF drainage via LD (n = 4), tissue plasminogen activator in addition to EVD (n = 3), intraventricular nimodipine (n = 2), and cisternal magnesium (n = 2). Results showed that intraventricular nimodipine decreased vasospasm (OR 0.59, 95% CI 0.37-0.94; p = 0.03). Therapies that significantly reduced DCI were CSF drainage via LD (OR 0.47, 95% CI 0.25-0.88; p = 0.02) and cisternal magnesium (OR 0.27, 95% CI 0.07-1.02; p = 0.05). CSF drainage via LD was also found to significantly reduce the incidence of cerebral infarction (OR 0.35, 95% 0.24-0.51; p < 0.001). Lastly, functional outcome was significantly better in patients who received CSF drainage via LD (OR 2.42, 95% CI 1.39-4.21; p = 0.002).

CONCLUSIONS

The authors' results showed that intrathecal therapy is a safe and feasible option following aSAH. It has been shown to attenuate cerebral vasospasm, reduce the incidence of DCI, and improve clinical outcome. The authors support the use of intrathecal management in the prevention and rescue management of cerebral vasospasm. More randomized controlled trials are warranted to determine the best combination of pharmaceutical agents and administration route in order to formulate a standardized treatment approach.

Nicardipine Prolonged Release Implants for Prevention of Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis

OBJECTIVES

A paucity of treatments to prevent delayed cerebral ischemia (DCI) has stymied recovery after aneurysmal subarachnoid hemorrhage (aSAH). Nicardipine has long been recognized as a potent cerebrovascular vasodilator with a history off-label use to prevent vasospasm and DCI. Multiple centers have developed nicardipine prolonged release implants (NPRI) that are directly applied during clip ligation to locally deliver nicardipine throughout the vasospasm window. Here we perform a systematic review and meta-analysis to assess whether NPRI confers protection against DCI and improves functional outcomes after aSAH.

MATERIALS AND METHODS

A systematic search of PubMed, Ovid Embase, and Cochrane databases was performed for studies reporting the use of NPRI after aSAH published after January 1, 1980. We included all studies assessing the association of NPRI with DCI and or functional outcomes. Findings from studies with control arms were analyzed using a random effects model. A separate network meta-analysis was performed, including controlled NPRI studies, single-arm NPRI reports, and the control-arms of modern aSAH randomized clinical trials as additional comparators.

RESULTS

The search identified 214 unique citations. Three studies with 284 patients met criteria for the random effects model. The pooled summary odds ratio for the association of NPRI and DCI was 0.21 (95% CI 0.09-0.49, p = 0.0002) with no difference in functional outcomes (OR 1.80, 95% CI 0.63 - 5.16, p = 0.28). 10 studies of 866 patients met criteria for the network meta-analysis. The pooled summary odds ratio for the association of NPRI and DCI was 0.30 (95% CI 0.13-0.89,p = 0.017) with a trend towards improved functional outcomes (OR 1.68, 0.63 - 4.13 95% CI, p = 0.101).

CONCLUSIONS

In these meta-analyses, NPRI decreases the incidence of DCI with a non-significant trend towards improvement in functional outcomes. Randomized trials on the role of intrathecal calcium channel blockers are warranted to evaluate these observations in a prospective manner.

Does intrathecal nicardipine for cerebral vasospasm following subarachnoid hemorrhage correlate with reduced delayed cerebral ischemia? A retrospective propensity score-based analysis

OBJECTIVE

Cerebral vasospasm and delayed cerebral ischemia (DCI) contribute to poor outcome following subarachnoid hemorrhage (SAH). With the paucity of effective treatments, the authors describe their experience with intrathecal (IT) nicardipine for this indication.

METHODS

Patients admitted to the Emory University Hospital neuroscience ICU between 2012 and 2017 with nontraumatic SAH, either aneurysmal or idiopathic, were included in the analysis. Using a propensity-score model, this patient cohort was compared to patients in the Subarachnoid Hemorrhage International Trialists (SAHIT) repository who did not receive IT nicardipine. The primary outcome was DCI. Secondary outcomes were long-term functional outcome and adverse events.

RESULTS

The analysis included 1351 patients, 422 of whom were diagnosed with cerebral vasospasm and treated with IT nicardipine. When compared with patients with no vasospasm (n = 859), the treated group was significantly younger (mean age 51.1 ± 12.4 years vs 56.7 ± 14.1 years, p < 0.001), had a higher World Federation of Neurosurgical Societies score and modified Fisher grade, and were more likely to undergo clipping of the ruptured aneurysm as compared to endovascular treatment (30.3% vs 11.3%, p < 0.001). Treatment with IT nicardipine decreased the daily mean transcranial Doppler velocities in 77.3% of the treated patients. When compared to patients not receiving IT nicardipine, treatment was not associated with an increased rate of bacterial ventriculitis (3.1% vs 2.7%, p > 0.1), yet higher rates of ventriculoperitoneal shunting were noted (19.9% vs 8.8%, p < 0.01). In a propensity score comparison to the SAHIT database, the odds ratio (OR) to develop DCI with IT nicardipine treatment was 0.61 (95% confidence interval [CI] 0.44-0.84), and the OR to have a favorable functional outcome (modified Rankin Scale score ≤ 2) was 2.17 (95% CI 1.61-2.91).

CONCLUSIONS

IT nicardipine was associated with improved outcome and reduced DCI compared with propensity-matched controls. There was an increased need for permanent CSF diversion but no other safety issues. These data should be considered when selecting medications and treatments to study in future randomized controlled clinical trials for SAH.

NEWTON-2 Cisternal (Nimodipine Microparticles to Enhance Recovery While Reducing Toxicity After Subarachnoid Hemorrhage): A Phase 2, Multicenter, Randomized, Open-Label Safety Study of Intracisternal EG-1962 in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

A sustained release microparticle formulation of nimodipine (EG-1962) was developed for treatment of patients with aneurysmal subarachnoid hemorrhage (aSAH).

OBJECTIVE

To assess safety, tolerability, and pharmacokinetics of intracisternal EG-1962 in an open-label, randomized, phase 2 study of up to 12 subjects.

METHODS

Subjects were World Federation of Neurological Surgeons grades 1 to 2, modified Fisher grades 2 to 4, and underwent aneurysm clipping within 48 h of aSAH. EG-1962, containing 600 mg nimodipine, was administered into the basal cisterns. Outcome on the extended Glasgow Outcome Scale (eGOS), pharmacokinetics, delayed cerebral ischemia and infarction, rescue therapy, and safety were evaluated.

RESULTS

The study was halted when a phase 3 study of intraventricular EG-1962 stopped because that study was unlikely to meet its primary endpoint. Six subjects were randomized (5 EG-1962 and 1 oral nimodipine). After 90-d follow-up, favorable outcome on the eGOS occurred in 1 of 5 EG-1962 and in the single oral nimodipine patient. Four EG-1962 and the oral nimodipine subject had angiographic vasospasm. One EG-1962 subject had delayed cerebral ischemia, and all subjects with angiographic vasospasm received rescue therapy except 1 EG-1962 patient. One subject treated with EG-1962 developed right internal carotid and middle cerebral artery narrowing 5 mo after placement of EG-1962, leading to occlusion and cerebral infarction. Pharmacokinetics showed similar plasma concentrations of nimodipine in both groups.

CONCLUSION

Angiographic vasospasm and unfavorable clinical outcome still occurred after placement of EG-1962. Internal carotid artery narrowing and occlusion after placement of EG-1962 in the basal cisterns has not been reported.

Clinical Pharmacology of Clazosentan, a Selective Endothelin A Receptor Antagonist for the Prevention and Treatment of aSAH-Related Cerebral Vasospasm

Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm and is associated with significant morbidity and mortality. It represents a major unmet medical need due to few treatment options with limited efficacy. The role of endothelin-1 (ET-1) and its receptor ET_A in the pathogenesis of aSAH-induced vasospasm suggests antagonism of this receptor as promising asset for pharmacological treatment. Clazosentan is a potent ET_A receptor antagonist for intravenous use currently under development for the prevention of aSAH-induced cerebral vasospasm. The pharmacokinetics of clazosentan are characterized by an intermediate clearance, a volume of distribution similar to that of the extracellular fluid volume, dose-proportional exposure, an elimination independent of drug-metabolizing enzymes, and a disposition mainly dependent on the hepatic uptake transporter organic anion transport polypeptide 1B1/1B3. In healthy subjects, clazosentan leads to an increase in ET-1 concentration and prevents the cardiac and renal effects mediated by infusion of ET-1. In patients, it significantly reduced the incidence of moderate or severe vasospasm as well as post-aSAH vasospasm-related morbidity and mortality. Clazosentan is well tolerated up to the expected therapeutic dose of 15 mg/h and, in aSAH patients, lung complications, hypotension, and anemia were adverse events more commonly reported following clazosentan than placebo. In summary, clazosentan has a pharmacokinetic, pharmacodynamic, and safety profile suitable to become a valuable asset in the armamentarium of therapeutic modalities to prevent aSAH-induced cerebral vasospasm.

Nimodipine Reappraised: An Old Drug With a Future

Nimodipine is a dihydropyridine calcium channel antagonist that blocks the flux of extracellular calcium through L-type, voltage-gated calcium channels. While nimodipine is FDAapproved for the prevention and treatment of neurological deficits in patients with aneurysmal subarachnoid hemorrhage (aSAH), it affects myriad cell types throughout the body, and thus, likely has more complex mechanisms of action than simple inhibition of cerebral vasoconstriction. Newer understanding of the pathophysiology of delayed ischemic injury after a variety of acute neurologic injuries including aSAH, traumatic brain injury (TBI) and ischemic stroke, coupled with advances in the drug delivery method for nimodipine, have reignited interest in refining its potential therapeutic use. In this context, this review seeks to establish a firm understanding of current data on nimodipine's role in the mechanisms of delayed injury in aSAH, TBI, and ischemic stroke, and assess the extensive clinical data evaluating its use in these conditions. In addition, we will review pivotal trials using locally administered, sustained release nimodipine and discuss why such an approach has evaded demonstration of efficacy, while seemingly having the potential to significantly improve clinical care.

Effectiveness of intrathecal nicardipine on cerebral vasospasm in non-traumatic subarachnoid hemorrhage: a systematic review

OBJECTIVE

The objective of this review was to determine the effectiveness of intrathecal nicardipine compared to usual care on cerebral vasospasm and its impact on the following outcome measures: mean flow velocities, angiographic and/or clinical vasospasm, and infection rates.

INTRODUCTION

The results of non-traumatic (aneurysmal) subarachnoid hemorrhage can have devastating effects on patients in terms of functional outcomes. Although other medications have been and continue to be used, Nimodipine is the only Food and Drug Administration-approved medication for treating and improving outcomes following non-traumatic subarachnoid hemorrhage, which may be caused by aneurysmal rupture or arteriovenous malformation. Cerebral vasospasm after non-traumatic subarachnoid hemorrhage is a major concern; cerebral vasospasm refers to the narrowing of the cerebral vessels, which can lead to stroke. Delayed ischemic neurological deficit, as a result of cerebral vasospasm, is the number one reason for death and disability following subarachnoid hemorrhage. This review will determine the effects that intrathecal nicardipine has on cerebral vasospam following non-traumatic subarachnoid hemorrhage.

INCLUSION CRITERIA

The participants of this review included adult patients (18 years and over) in intensive care units. The patients must have had a subarachnoid hemorrhage without history of trauma as cause of subarachnoid hemorrhage, along with the presence of an external ventricular drain. The intervention was administration of intrathecal nicardipine in patients with cerebral vasospasm as a result of non-traumatic subarachnoid hemorrhage. The comparator was usual care, which does not include use of intrathecal nicardipine as part of the treatment regimen. The current review considered both experimental and quasi-experimental study designs. The primary outcomes measured included presence of cerebral vasospasm (identified by mean flow velocities measured by transcranial Doppler and the presence of angiographic vasospasm identified on angiogram) and clinical/symptomatic vasospasm. Secondarily, infection rates as a result of intrathecal nicardipine administration were evaluated.

METHODS

The search strategy aimed to find both published and unpublished studies. Seven databases were searched with no date limitations due to the limited amount of research on this topic.Two independent reviewers assessed the methodological validity of the papers prior to inclusion in the review using the standardized critical appraisal instruments from Joanna Briggs Institute System for the Unified Management, Assessment and Review of Information (JBI SUMARI).Quantitative data was extracted from included studies using the standardized data extraction tool from JBI SUMARI.Statistical pooling was not possible; therefore findings were presented in a narrative form.

RESULTS

Two studies examined the effect that intrathecal nicardipine has on cerebral vasospasm, clinical/symptomatic vasospasm and safety concerns (i.e. infection). The studies indicate that intrathecal nicardipine has shown potential benefits and safety in the treatment of cerebral vasospasm.

CONCLUSIONS

Although intrathecal nicardipine has shown potential to be effective in treating cerebral vasospasm, variance existed among those who received intrathecal nicardipine. In terms of safety, one study had no occurrences of associated bacterial meningitis and the other study had two reported cases of bacterial meningitis out of 50 among those who received intrathecal nicardipine. Limited studies on the use of intrathecal nicardipine following non-traumatic subarachnoid hemorrhage and lack of pooling of results for this review demonstrate the need for more research in this field.

Outcome of Oral and Intra-arterial Nimodipine Administration After Aneurysmal Subarachnoid Haemorrhage - A Single-centre Study

BACKGROUND

Oral nimodipine is administered to improve clinical outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). In this study, clinical outcome in patients with and without oral nimodipine administration was assessed.

MATERIALS AND METHODS

A total of 105 patients did not receive oral nimodipine but did receive intra-arterial nimodipine in the occurrence of hemodynamically relevant vasospasm after aSAH, whereas 74 patients received applications of both. Demographic/radiological details and clinical presentation were abstracted from the case records.

RESULTS

Patient baseline characteristics were comparable, a predominance of endovascular coiling was shown in cohort 2 (p=0.0135). Severity of initial aSAH and clinical status at admission (Hunt and Hess) was significantly higher in those receiving oral nimodipine. Incidence of angiographic vasospasm was significantly higher in patients not treated with oral nimodipine (p=0.0305); a significantly better outcome measured by the National Institute of Health Stroke Scale (p=0.0213), was noted in those receiving oral nimodipine.

CONCLUSION

Oral nimodipine administration improved clinical outcome of patients after aSAH and should be administered routinely for such patients.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

NEWTON: Nimodipine Microparticles to Enhance Recovery While Reducing Toxicity After Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality. EG-1962 is a sustained-release microparticle formulation of nimodipine that has shown preclinical efficacy when administered intraventricularly or intracisternally to dogs with SAH, without evidence of toxicity at doses in the anticipated therapeutic range. Thus, we propose to administer EG-1962 to humans in order to assess safety and tolerability and determine a dose to investigate efficacy in subsequent clinical studies.

METHODS

We describe a Phase 1/2a multicenter, controlled, randomized, open-label, dose escalation study to determine the maximum tolerated dose (MTD) and assess the safety and tolerability of EG-1962 in patients with aSAH. The study will comprise two parts: a dose escalation period (Part 1) to determine the MTD of EG-1962 and a treatment period (Part 2) to assess the safety and tolerability of the selected dose of EG-1962. Patients with a ruptured saccular aneurysm treated by neurosurgical clipping or endovascular coiling will be considered for enrollment. Patients will be randomized to receive either EG-1962 (study drug: nimodipine microparticles) or oral nimodipine in the approved dose regimen (active control) within 60 h of aSAH.

RESULTS

Primary objectives are to determine the MTD and the safety and tolerability of the selected dose of intraventricular EG-1962 as compared to enteral nimodipine. The secondary objective is to determine release and distribution by measuring plasma and CSF concentrations of nimodipine. Exploratory objectives are to determine the incidence of delayed cerebral infarction on computed tomography, clinical features of delayed cerebral ischemia, angiographic vasospasm, and incidence of rescue therapy and clinical outcome. Clinical outcome will be determined at 90 days after aSAH using the extended Glasgow outcome scale, modified Rankin scale, Montreal cognitive assessment, telephone interview of cognitive status, and Barthel index.

CONCLUSION

Here, we describe a Phase 1/2a multicenter, controlled, randomized, open-label, dose escalation study to determine the MTD and assess the safety and tolerability of EG-1962 in patients with aSAH.

Pharmacological agents in aneurysmal subarachnoid hemorrhage: successes and failures

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating condition with high mortality. Proper management of this complex disease requires early surgical intervention followed by medical therapy. Pharmacological agents that unequivocally improve outcomes in aSAH are scarce.

METHODS

The authors performed an exhaustive query of several databases including MEDLINE, the CENTRAL Register of Controlled Trials, and the Cochrane Database of Systematic Reviews for specific evidence on key medications that have been used in the treatment of aSAH.

RESULTS

The bulk of the data available pertained to the following medications: calcium channel blockers, magnesium, statins, antifibrinolytics, aspirin, glucocorticoids, clazosentan, and tirilazad. Except for calcium channel blockers, the authors could not find any hard evidence that any of these agents affected outcome to a tangible degree. Aspirin may have some promise in prevention of aneurysm rupture and incidence of aSAH, but more substantive data are needed to conclusively corroborate this.

CONCLUSIONS

Investigational efforts to attain outcome-modifying agents have had dubious results, but the inquest for discovery should not discontinue.

Aneurysmal subarachnoid hemorrhage: pathobiology, current treatment and future directions

Aneurysmal subarachnoid hemorrhage is the most devastating form of stroke. Many pathological mechanisms ensue after cerebral aneurysm rupture, including hydrocephalus, apoptosis of endothelial cells and neurons, cerebral edema, loss of blood-brain barrier, abnormal cerebral autoregulation, microthrombosis, cortical spreading depolarization and macrovascular vasospasm. Although studied extensively through experimental and clinical trials, current treatment guidelines to prevent delayed cerebral ischemia is limited to oral nimodipine, maintenance of euvolemia, induction of hypertension if ischemic signs occur and endovascular therapy for patients with continued ischemia after induced hypertension. Future investigations will involve agents targeting vasodilation, anticoagulation, inhibition of apoptosis pathways, free radical neutralization, suppression of cortical spreading depolarization and attenuation of inflammation.

Absorption, elimination and cerebrospinal fluid concentrations of nimodipine in healthy beagle dogs receiving human intravenous and oral formulation

Nimodipine is an L-type calcium channel blocker and is used to treat vasospasm in patients with subarachnoid hemorrhage. Its putative mechanism of action is relaxation of smooth muscle cells in cerebral arteries. In addition, nimodipine may have pleiotropic effects against vasospasm. Systemic hypotension is an adverse effect when patients are treated with oral or intravenous nimodipine. Intracranial administration of nimodipine formulations may produce higher concentration of nimodipine in the cerebrospinal fluid (CSF) than is possible to achieve orally or intravenously, while resulting in lower incidence of systemic hypotension. The aim of this study was to provide information on plasma and CSF levels of nimodipine in beagle dogs as a comparative data for development of experimental intracranial treatment modalities. Plasma levels of nimodipine were measured after current 30 and 60 mg single oral dose of nimodipine (Nimotop(®) 30 mg tablets), a single intravenous bolus 0.72 mg/dog of nimodipine (Nimotop(®) 0.2 mg/ml infusion solution) and CSF levels after 60 mg single oral dose of nimodipine. CSF/Plasma concentration ratio of nimodipine after oral administration of 60 mg at 1 h was 0.013 ± 0.0005. The mean terminal elimination half-life of nimodipine after i.v. bolus dose 0.72 mg was 1.8 h and mean plasma clearance was 40.3 and 3.4 l/h/kg. Absolute bioavailability was 22 %. Maximum plasma concentration and area under the plasma concentration-time curve from time of administration until the last measurable plasma concentration increased in a dose-proportional manner comparing the exposure parameters at oral doses of 30 and 60 mg. Individual variation in the kinetic profile of nimodipine was measured.

Intracranial biodegradable silica-based nimodipine drug release implant for treating vasospasm in subarachnoid hemorrhage in an experimental healthy pig and dog model

Nimodipine is a widely used medication for treating delayed cerebral ischemia (DCI) after subarachnoid hemorrhage. When administrated orally or intravenously, systemic hypotension is an undesirable side effect. Intracranial subarachnoid delivery of nimodipine during aneurysm clipping may be more efficient way of preventing vasospasm and DCI due to higher concentration of nimodipine in cerebrospinal fluid (CSF). The risk of systemic hypotension may also be decreased with intracranial delivery. We used animal models to evaluate the feasibility of surgically implanting a silica-based nimodipine releasing implant into the subarachnoid space through a frontotemporal craniotomy. Concentrations of released nimodipine were measured from plasma samples and CSF samples. Implant degradation was followed using CT imaging. After completing the recovery period, full histological examination was performed on the brain and meninges. The in vitro characteristics of the implant were determined. Our results show that the biodegradable silica-based implant can be used for an intracranial drug delivery system and no major histopathological foreign body reactions were observed. CT imaging is a feasible method for determining the degradation of silica implants in vivo. The sustained release profiles of nimodipine in CSF were achieved. Compared to a traditional treatment, higher nimodipine CSF/plasma ratios can be obtained with the implant.

Intrathecal application of the nimodipine slow-release microparticle system eg-1962 for prevention of delayed cerebral ischemia and improvement of outcome after aneurysmal subarachnoid hemorrhage

The effective reduction of delayed cerebral ischemia (DCI), a main contributor for poor outcome following aneurysmal subarachnoid hemorrhage (SAH), remains challenging. Previous clinical trials on systemic pharmaceutical treatment of SAH mostly failed to improve outcome, probably because of insensitive pharmaceutical targets and outcome measures, small sample size, insufficient subarachnoid drug concentrations and also detrimental, systemic effects of the experimental treatment per se. Interestingly, in studies that are more recent, intrathecal administration of nicardipine pellets following surgical aneurysm repair was suggested to have a beneficial effect on DCI and neurological outcome. However, this positive effect remained restricted to patients who were treated surgically for a ruptured aneurysm. Because of the favorable results of the preclinical data on DCI and neurological outcome in the absence of neurotoxicity or systemic side effects, we are initiating clinical trials. The PROMISE (Prolonged Release nimOdipine MIcro particles after Subarachnoid hemorrhage) trial is designed as an unblinded, nonrandomized, single-center, single-dose, dose-escalation safety and tolerability phase 1 study in patients surgically treated for aSAH and will investigate the effect of intracisternal EG-1962 administration. The NEWTON (Nimodipine microparticles to Enhance recovery While reducing TOxicity after subarachNoid hemorrhage) trial is a phase 1/2a multicenter, controlled, randomized, open-label, dose-escalation, safety, tolerability, and pharmacokinetic study comparing EG-1962 and nimodipine in patients with aneurysmal SAH.

Cerebral vasospasm pharmacological treatment: an update

Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th-7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasospasm. Triple "H" therapy, balloon and chemical angioplasty with superselective intra-arterial injection of vasodilators, administration of substances like magnesium sulfate, statins, fasudil hydrochloride, erythropoietin, endothelin-1 antagonists, nitric oxide progenitors, and sildenafil, are some of the therapeutic protocols, which are currently employed for managing patients with aSAH. Intense pathophysiological mechanism research has led to the identification of various mediators of cerebral vasospasm, such as endothelium-derived, vascular smooth muscle-derived, proinflammatory mediators, cytokines and adhesion molecules, stress-induced gene activation, and platelet-derived growth factors. Oral, intravenous, or intra-arterial administration of antagonists of these mediators has been suggested for treating patients suffering a-SAH vasospam. In our current study, we attempt to summate all the available pharmacological treatment modalities for managing vasospasm.

Novel treatments for vasospasm after subarachnoid hemorrhage

PURPOSE OF REVIEW

Cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage remains a considerable challenge in neurocritical care medicine. This review aims to cover the recent novel aspects and results in CVS treatment.

RECENT FINDINGS

On the basis of the recent literature, treatment focusing on CVS alone is outdated. A considerable amount of evidence suggests CVS not to be the sole cause of delayed cerebral ischemia (DCI) and poor outcome. Early brain injury, cortical spreading depolarization, inflammation and microthrombosis have recently been discussed as additional factors. The results of a well designed phase III trial, using an endothelin-1 antagonist, indicated a decrease in the occurrence of CVS but did not change the clinical outcome significantly. Induced hypertension is currently recommended for treating suspected DCI, whereas hemodilution and hypervolemia are not. Endovascular intervention is only recommended in case of refractory symptomatic CVS. A couple of newer treatment strategies are under evaluation. Phase III trials are underway for magnesium sulfate and statins. Clinical trials aiming specifically at recently discussed factors other than CVS have not been reported.

SUMMARY

Reviewing the recent literature, there have been some updates on recommendations and newer treatment modalities are under evaluation. However, a novel treatment with convincing evidence has not been reported so far.

The use of nicardipine prolonged release implants (NPRI) in microsurgical clipping after aneurysmal subarachnoid haemorrhage: comparison with endovascular treatment

BACKGROUND

Nicardipine prolonged release implants (NPRI) have been shown to decrease the incidence of cerebral vasospasm and infarcts significantly in patients after aneurysmal subarachnoid haemorrhage (SAH) following microsurgical clipping. Yet, the comparison with results after endovascular coiling is lacking. This study was conducted to determine the differences in the incidence of cerebral vasospasm and infarctions between those two treatment modalities

METHODS

The design of this investigation reflects a case-control study; 27 patients suffering from acute SAH were treated by microsurgical clipping and received an intracisternal implantation of NPRI. Twenty-seven matching consecutive patients after microsurgical treatment without implantation of NPRI or endovascular treatment, respectively, served as controls. The incidence of angiographic vasospasm and cerebral infarctions were documented.

RESULTS

All groups were comparable concerning demographics and severity of SAH. Twenty-four of 81 patients developed angiographic vasospasm (>33% constriction). The incidence of vasospasm was 48%, 44% and 11% for patients after endovascular treatment, microsurgical clipping without NPRI and microsurgical clipping with NPRI, respectively. New cerebral infarctions occurred in 28%, 22% and 7% of the treated patients, respectively. A good clinical recovery 1 year after the initial bleeding (modified Rankin scale 0-2) was seen in 48%, 50% and 77% of the treated patients, respectively.

CONCLUSION

The use of NPRI during microsurgical clipping was confirmed to be safe and effective. Patients who received intracisternally implanted NPRI during clipping after aneurysmal SAH yielded significantly lower vasospasm and infarction rates, and showed a better clinical outcome when compared with clipping without NPRI and also when compared with endovascular coiling.