Effects of prophylactic intrathecal administrations of nicardipine on vasospasm in patients with severe aneurysmal subarachnoid haemorrhage

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

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.

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 Role of Cisternostomy and Cisternal Drainage in the Treatment of Aneurysmal Subarachnoid Hemorrhage: A Comprehensive Review

Aneurysmal subarachnoid hemorrhage (aSAH) provokes a cascade reaction that is responsible for early and delayed brain injuries mediated by intracranial hypertension, hydrocephalus, cerebral vasospasm (CV), and delayed cerebral ischemia (DCI), which result in increased morbidity and mortality. During open microsurgical repair, cisternal access is achieved essentially to gain proximal vascular control and aneurysm exposition. Cisternostomy also allows brain relaxation, removal of cisternal clots, and restoration of the CSF dynamics through the communication between the anterior and posterior circulation cisterns and the ventricular system, with the opening of the Membrane of Liliequist and lamina terminalis, respectively. Continuous postoperative CSF drainage through a cisternal drain (CD) is a valuable option for treating acute hydrocephalus and intracranial hypertension. Moreover, it efficiently removes the blood and toxic degradation products, with a potential benefit on CV, DCI, and shunt-dependent hydrocephalus. Finally, the CD is an effective pathway to administer vasoactive, fibrinolytic, and anti-oxidant agents and shows promising results in decreasing CV and DCI rates while minimizing systemic effects. We performed a comprehensive review to establish the adjuvant role of cisternostomy and CD performed in cases of direct surgical repair for ruptured intracranial aneurysms and their role in the prevention and treatment of aSAH complications.

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.

Microvascular cerebral blood flow response to intrathecal nicardipine is associated with delayed cerebral ischemia

One of the common complications of non-traumatic subarachnoid hemorrhage (SAH) is delayed cerebral ischemia (DCI). Intrathecal (IT) administration of nicardipine, a calcium channel blocker (CCB), upon detection of large-artery cerebral vasospasm holds promise as a treatment that reduces the incidence of DCI. In this observational study, we prospectively employed a non-invasive optical modality called diffuse correlation spectroscopy (DCS) to quantify the acute microvascular cerebral blood flow (CBF) response to IT nicardipine (up to 90 min) in 20 patients with medium-high grade non-traumatic SAH. On average, CBF increased significantly with time post-administration. However, the CBF response was heterogeneous across subjects. A latent class mixture model was able to classify 19 out of 20 patients into two distinct classes of CBF response: patients in Class 1 (n = 6) showed no significant change in CBF, while patients in Class 2 (n = 13) showed a pronounced increase in CBF in response to nicardipine. The incidence of DCI was 5 out of 6 in Class 1 and 1 out of 13 in Class 2 (p < 0.001). These results suggest that the acute (<90 min) DCS-measured CBF response to IT nicardipine is associated with intermediate-term (up to 3 weeks) development of DCI.

Safety and Tolerability of Concentrated Intraventricular Nicardipine for Poor-Grade Aneurysmal Subarachnoid Hemorrhage–Related Vasospasm

Objective: To report the preliminary safety, tolerability, and cerebral spinal fluid (CSF) sampling utility of serial injections of concentrated intraventricular nicardipine (IVN) in the treatment of aneurysmal subarachnoid hemorrhage (aSAH). Methods: We report the clinical, radiographic, and laboratory safety and tolerability data of a retrospective case series from a single academic medical center. All patients with aSAH developed vasospasm despite enteral nimodipine and received serial injections of concentrated IVN (2.5 mg/mL). CSF injection safety, tolerability, and utility are defined and reported. Results: A total of 59 doses of concentrated IVN were administered to three patients with poor-grade SAH. In Case 1, a 33-year-old man with modified Fisher scale (mFS) grade 4 and Hunt-Hess scale (HH) score 4 received 26 doses; in Case 2, a 36-year-old woman with mFS grade 4 and HH score 5 received 13 doses; and in Case 3, a 70-year-old woman with mFS grade 3 and HH score 4 received 20 doses. No major safety or tolerability events occurred. Two patients were discharged to a rehabilitation facility, and one died after discharge from the hospital. Conclusions: A concentrated 4 mg IVN dose (2.5 mg/mL) in a 1.6 mL injection appears relatively safe and tolerable and potentially offers a second-line strategy for treating refractory vasospasm in poor-grade SAH without compromising intracranial pressure or cerebral perfusion pressure.

Efficacy of combined intravenous plus intrathecal nimodipine administration in patients with severe cerebral vasospasm post‑aneurysmal subarachnoid hemorrhage: A retrospective cohort study

Aneurysmal subarachnoid hemorrhage (aSAH) and the ensuing cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) comprise the main reasons for morbidity and mortality in affected patients. The present study aimed to evaluate the efficacy of the use of combined intravenous (IV) and intrathecal (IT) nimodipine therapy for preventing permanent neurological deterioration and DCI in patients suffering from CV post-hemorrhage. The evaluation was performed using computed tomography perfusion and transcranial doppler ultrasound. The present retrospective cohort study analyzed 14 out of 146 patients diagnosed with vasospasm due to spontaneous or aSAH. These patients were divided into two groups as follows: i) The IV group, which included patients treated with only IV nimodipine; and ii) the IV + IT group, which included patients who received IV nimodipine in combination with IT nimodipine. Of the 14 patients, 7 patients were males (50%), and the mean age was 50.9 years (SD ±19 years). In total, 6 patients [42.8%; 5 (35.7%) from group A and 1 (7.1%) from group B], who experienced clinical symptoms with severe CV, were administered intra-arterial calcium channel therapy or/and IT nimodipine following the early identification of symptomatic vasospasm. The rate of adverse ischemic events was lower with IT nimodipine management during the 1 month of follow-up (6 vs. 2 events; odds ratio, 15.00; 95% confidence interval, 1.03-218.31; P=0.031). On the whole, the findings of the present study suggest that the combined use of IT nimodipine with IV admission for patients post-aSAH who developed severe CV is a safe procedure that may prevent permanent neurological deterioration and delay unfavorable ischemic incidents.

Correlation of intraventricular nicardipine for refractory vasospasm in aneurysmal subarachnoid hemorrhage with improved neurophysiology on intracranial multimodality monitoring: illustrative case

BACKGROUND

Cerebral vasospasm after aneurysmal subarachnoid hemorrhage can lead to considerable mortality and morbidity affecting the intracranial vessels, leading to delayed cerebral ischemia and stroke. Therapeutic options for patients with treatment-refractory vasospasm are limited, particularly in the setting of significant cardiopulmonary disease. Administration of nicardipine, a calcium channel blocker, into the intrathecal space may represent a potential treatment option for this population.

OBSERVATIONS

A 56-year-old woman had treatment-refractory vasospasm, severe acute respiratory distress syndrome, and Takotsubo cardiomyopathy. As an adjunct to vasopressor administration and endovascular intraarterial calcium channel blocker administration, the patient received intraventricular nicardipine. The patient demonstrated improved neurophysiology on invasive multimodality neuromonitoring, with increased cerebral blood flow and oxygenation as a result of intraventricular nicardipine administration.

LESSONS

Intraventricular nicardipine can be used as rescue therapy for patients with treatment-refractory cerebral vasospasm. This case demonstrates that intrathecal nicardipine may prevent delayed ischemic neurological deficits and improve outcomes.

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.

An overview of pharmacotherapy for cerebral vasospasm and delayed cerebral ischemia after subarachnoid hemorrhage

Introduction: Survival from aneurysmal subarachnoid hemorrhage has increased in the past few decades. However, functional outcome after subarachnoid hemorrhage is still suboptimal. Delayed cerebral ischemia (DCI) is one of the major causes of morbidity.Areas covered: Mechanisms underlying vasospasm and DCI after aneurysmal subarachnoid hemorrhage and pharmacological treatment are summarized in this review.Expert opinion: Oral nimodine, an L-type dihydropyridine calcium channel blocker, is the only FDA-approved drug for the prevention and treatment of neurological deficits after aneurysmal subarachnoid hemorrhage. Fasudil, a potent Rho-kinase inhibitor, has also been shown to improve the clinical outcome and has been approved in some countries for use in patients with aneurysmal subarachnoid hemorrhage. Although other drugs, including nicardipine, cilostazol, statins, clazosentan, magnesium and heparin, have been expected to have beneficial effects on DCI, there has been no convincing evidence supporting the routine use of those drugs in patients with aneurysmal subarachnoid hemorrhage in clinical practice. Further elucidation of the mechanisms underlying DCI and the development of effective therapeutic strategies for DCI, including combination therapy, are necessary to further improve the functional outcome and mortality after subarachnoid hemorrhage.

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.

Nimodipine pharmacokinetics after intraventricular injection of sustained-release nimodipine for subarachnoid hemorrhage

OBJECTIVE

The objective of this study was to measure the concentration of nimodipine in CSF and plasma after intraventricular injection of a sustained-release formulation of nimodipine (EG-1962) in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Patients with SAH repaired by clip placement or coil embolization were randomized to EG-1962 or oral nimodipine. Patients were classified as grade 2-4 on the World Federation of Neurosurgical Societies grading scale for SAH and had an external ventricular drain inserted as part of their standard of care. Cohorts of 12 patients received 100-1200 mg of EG-1962 as a single intraventricular injection (9 per cohort) or they remained on oral nimodipine (3 per cohort). Plasma and CSF were collected from each patient for measurement of nimodipine concentrations and calculation of maximum plasma and CSF concentration, area under the concentration-time curve from day 0 to 14, and steady-state concentration.

RESULTS

Fifty-four patients in North America were randomized to EG-1962 and 18 to oral nimodipine. Plasma concentrations increased with escalating doses of EG-1962, remained stable for 14 to 21 days, and were detectable at day 30. Plasma concentrations in the oral nimodipine group were more variable than for EG-1962 and were approximately equal to those occurring at the EG-1962 800-mg dose. CSF concentrations of nimodipine in the EG-1962 groups were 2-3 orders of magnitude higher than in the oral nimodipine group, in which nimodipine was only detected at low concentrations in 10% (21/213) of samples. In the EG-1962 groups, CSF nimodipine concentrations were 1000 times higher than plasma concentrations.

CONCLUSIONS

Plasma concentrations of nimodipine similar to those achieved with oral nimodipine and lasting for 21 days could be achieved after a single intraventricular injection of EG-1962. The CSF concentrations from EG-1962, however, were at least 2 orders of magnitude higher than those with oral nimodipine. These results supported a phase 3 study that demonstrated a favorable safety profile for EG-1962 but yielded inconclusive efficacy results due to notable differences in clinical outcome based on baseline disease severity.Clinical trial registration no.: NCT01893190 (ClinicalTrials.gov).

Systematic Review of Intrathecal Nicardipine for the Treatment of Cerebral Vasospasm in Aneurysmal Subarachnoid Hemorrhage

Intrathecal nicardipine has been shown to have some efficacy for the treatment of symptomatic cerebral vasospasm in aneurysmal subarachnoid hemorrhage (aSAH). We performed a PRISMA-based systematic review of intrathecal nicardipine for the treatment of cerebral vasospasm in aneurysmal subarachnoid hemorrhage. A total of 825 articles were reviewed. After duplicates were removed and the search criteria was applied, 9 articles remained that were eligible for inclusion and analysis. 377 patients received a total of 6,596 injections of intrathecal nicardipine for aSAH-related cerebral vasospasm. The cumulative ventriculostomy-associated infection risk was 6%. Intrathecal nicardipine injections for aSAH-related cerebral vasospasm appears efficacious and safe. Administration of 4 mg of nicardipine every 12 hours was the most commonly reported dosing regimen. Intrathecal nicardipine decreases mean flow velocities on transcranial Doppler and reduces angiographic and clinical vasospasm. The infection risk appears to be in-line with studies in which rates of EVD-related infections have been reported.

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.

Protective effect of unilateral vasospasm in the setting of HHH-associated posterior reversible encephalopathy syndrome: case report, review of the literature, and treatment considerations

Background

Hyperdynamic therapy, also called triple-H therapy, is the standard treatment and prophylaxis for aneurysmal-associated vasospasm. In patients who are able to tolerate cardiopulmonary stressors induced by this therapy, it is of benefit as a modality for prevention and treatment of delayed ischemic neurologic deficit. However, it can be a cause of significant cardiopulmonary or neurologic sequelae. In rare cases, it can be associated with posterior reversible encephalopathy syndrome (PRES), secondary to prolonged vasopressor and hypertensive therapies.

Case presentation

We present the case of a patient with right-sided aneurysmal-associated vasospasm who, after 10 days of triple-H therapy, experienced a seizure and was found to have left-sided PRES. Right-sided vasospasm served as a protective mechanism from triple-H therapy-associated PRES. It presented a treatment conundrum due to contradictory perfusion requirements. Hypertensive therapy was curtailed and in efforts to preserve local cerebral perfusion and vasodilation, local therapy with intrathecal nicardipine was initiated. We present our case, a review of the literature, and management considerations.

Conclusions

Therapies that have conventionally functioned as second line treatments for aneurysmal subarachnoid hemorrhage (intra-arterial vasodilators and intrathecal vasodilators) may be beneficial as earlier treatments in the setting of vasospasm given the systemic difficulties and complications associated with HHH therapy in patients with PRES.

Prolonged Intracisternal Papaverine Toxicity: Index Case Description and Proposed Mechanism of Action

BACKGROUND

Intracisternal papaverine (iPPV) is a vasodilator used for prophylaxis of intraoperative vasospasm during aneurysmal clipping. Postoperative side effects of iPPV include transient cranial nerve palsies, most commonly mydriasis owing to oculomotor nerve involvement, with rapid resolution.

METHODS

We critically reviewed current literature on the adverse effects of iPPV in aneurysmal surgery with a focus on oculomotor nerve involvement. We also present the index case of prolonged bilateral mydriasis secondary to iPPV irrigation toxicity and its putative underlying mechanism.

RESULTS

Papaverine toxicity occurs in the setting of its antimuscarinic action and blood-cerebrospinal fluid and blood-brain barrier compromise owing to acute subarachnoid hemorrhage and direct effect of papaverine. Our patient also experienced severe vasospasm and a minor stroke, both contributing to further blood-brain barrier disruption, and relatively acidic pH of the subarachnoid hemorrhage milieu.

CONCLUSIONS

We propose that these factors perpetuate phase dynamics of papaverine crystals and facilitate a sustained slow release of papaverine within the cisternal system. Were it indicated, 0.3% iPPV would reasonably diminish the risk for neurotoxicity.

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.

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

Delayed cerebral ischaemia has been described as the single most important cause of morbidity and mortality in patients who survive the initial aneurysmal subarachnoid haemorrhage. Our understanding of the pathophysiology of delayed cerebral ischaemia is meagre at best and the calcium channel blocker nimodipine remains the only intervention to consistently improve functional outcome after aneurysmal subarachnoid haemorrhage. There is substantial evidence to support cerebral vessel narrowing as a causative factor in delayed cerebral ischaemia, but contemporary research demonstrating improvements in vessel narrowing has failed to show improved functional outcomes. This has encouraged researchers to investigate other potential causes of delayed cerebral ischaemia, such as early brain injury, microthrombosis, and cortical spreading depolarisation. Adherence to a common definition of delayed cerebral ischaemia is needed in order to allow easier assessment of studies using multiple different terms. Furthermore, improved recognition of delayed cerebral ischaemia would not only allow for faster treatment but also better assessment of interventions. Finally, understanding nimodipine's mechanism of action may allow us to develop similar agents with improved efficacy.

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.

Current options for the management of aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm: a comprehensive review of the literature

OBJECTIVES

Cerebral vasospasm is one of the leading causes of morbi-mortality following aneurysmal subarachnoid hemorrhage. The aim of this article is to discuss the current status of vasospasm therapy with emphasis on endovascular treatment.

METHODS

A comprehensive review of the literature obtained by a PubMed search. The most relevant articles related to medical, endovascular and alternative therapies were selected for discussion.

RESULTS

Current accepted medical options include the oral nimodipine and 'triple-H' therapy (hypertension, hypervolemia and hemodilution). Nimodipine remains the only modality proven to reduce the incidence of infarction. Although widely used, 'triple-H' therapy has not been demonstrated to significantly change overall outcome after cerebral vasospasm. Indeed, both induced hypervolemia and hemodilution may have deleterious effects, and more recent physiologic data favor normovolemia with induced hypertension or optimization of cardiac output. Endovascular options include percutaneous transluminal balloon angioplasty (PTA) and intra-arterial (IA) infusion of vasodilators. Multiple case reports and case series have been encountered in the literature using different drug regimens with diverse mechanisms of action. Compared with PTA, IA drug infusion has the advantages of distal penetration and a better safety profile. Its main disadvantages are the more frequent need for repeat treatments and its systemic hemodynamic repercussions. Alternative options using intraventricular/cisternal drug therapy and flow augmentation strategies have also shown possible benefits; however, their use is not yet as well established.

CONCLUSION

Blood pressure or cardiac output optimization should be the mainstay of hyperdynamic therapy. Endovascular treatment appears to have a positive impact on neurological outcome compared with the natural history of the disease. The role of intraventricular therapy and flow augmentation strategies in association with medical and endovascular treatment may, in the future, play a growing role in the management of patients with severe refractory vasospasm.

Subarachnoid hemorrhage and the distribution of drugs delivered into the cerebrospinal fluid. Laboratory investigation

OBJECT

Investigators in experimental and clinical studies have used the intrathecal route to deliver drugs to prevent or treat vasospasm. However, a clot near an artery or arteries after subarachnoid hemorrhage (SAH) may hamper distribution and limit the effects of intrathecally delivered compounds. In a primate model of right middle cerebral artery (MCA) SAH, the authors examined the distribution of Isovue-M 300 and 3% Evans blue after infusion into the cisterna magna CSF.

METHODS

Ten cynomolgus monkeys were assigned to SAH and sham SAH surgery groups (5 in each group). Monkeys received CSF injections as long as 28 days after SAH and were killed 3 hours after the contrast/Evans blue injection. The authors assessed the distribution of contrast material on serial CT within 2 hours after contrast injection and during autopsy within 3 hours after Evans blue staining.

RESULTS

Computed tomography cisternographies showed no contrast in the vicinity of the right MCA (p < 0.05 compared with left); the distribution of contrast surrounding the entire right cerebral hemisphere was substantially reduced. Postmortem analysis demonstrated much less Evans blue staining of the right hemisphere surface compared with the left. Furthermore, the Evans blue dye did not penetrate into the right sylvian fissure, which occurred surrounding the left MCA. The authors observed the same pattern of changes and differences in contrast distribution between SAH and sham SAH animals and between the right and the left hemispheres on Days 1, 3, 7, 14, 21, and 28 after SAH.

CONCLUSIONS

Intrathecal drug distribution is substantially limited by SAH. Thus, when using intrathecal drug delivery after SAH, vasoactive drugs are unlikely to reach the arteries that are at the highest risk of delayed cerebral vasospasm.

Use of intrathecal nicardipine for aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm

BACKGROUND

Cerebral vasospasm leading to delayed ischemia is a common and serious complication of aneurysmal subarachnoid hemorrhage that often results in increased morbidity and mortality. Treatments for cerebral vasospasm, including triple-H therapy (therapeutic hypervolemia, hypertension, and hemodilution), nimodipine, balloon angioplasty, and intra-arterial vasodilators have limitations in their efficacy and safety profiles. Nicardipine, a calcium channel blocker, is available for intravenous administration for blood pressure reduction. A recent study reported its efficacy in the treatment of cerebral vasospasm when given intrathecally (IT). We present our experiences with IT nicardipine for treatment of cerebral vasospasm.

METHODS

IT nicardipine was administered to six patients with aneurysmal subarachnoid hemorrhage after prophylactic and aggressive therapeutic management for vasospasm failed.

RESULTS

In these patients, IT nicardipine treatment was followed within 8 hours by a 43.1 +/- 31.0 cm/s decrease in middle cerebral arterial flow velocity, as measured by transcranial Doppler ultrasound.

CONCLUSIONS

Based on these positive results, we believe that larger scale studies evaluating the safety and efficacy of IT nicardipine for the management of cerebral vasospasm are warranted.

Clinical review: Prevention and therapy of vasospasm in subarachnoid hemorrhage

Vasospasm is one of the leading causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Radiographic vasospasm usually develops between 5 and 15 days after the initial hemorrhage, and is associated with clinically apparent delayed ischemic neurological deficits (DID) in one-third of patients. The pathophysiology of this reversible vasculopathy is not fully understood but appears to involve structural changes and biochemical alterations at the levels of the vascular endothelium and smooth muscle cells. Blood in the subarachnoid space is believed to trigger these changes. In addition, cerebral perfusion may be concurrently impaired by hypovolemia and impaired cerebral autoregulatory function. The combined effects of these processes can lead to reduction in cerebral blood flow so severe as to cause ischemia leading to infarction. Diagnosis is made by some combination of clinical, cerebral angiographic, and transcranial doppler ultrasonographic factors. Nimodipine, a calcium channel antagonist, is so far the only available therapy with proven benefit for reducing the impact of DID. Aggressive therapy combining hemodynamic augmentation, transluminal balloon angioplasty, and intra-arterial infusion of vasodilator drugs is, to varying degrees, usually implemented. A panoply of drugs, with different mechanisms of action, has been studied in SAH related vasospasm. Currently, the most promising are magnesium sulfate, 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, nitric oxide donors and endothelin-1 antagonists. This paper reviews established and emerging therapies for vasospasm.

Effect of nicardipine prolonged-release implants on cerebral vasospasm and clinical outcome after severe aneurysmal subarachnoid hemorrhage: a prospective, randomized, double-blind phase IIa study

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the effect of nicardipine prolonged-release implants (NPRIs) on cerebral vasospasm and clinical outcome after severe subarachnoid hemorrhage.

METHODS

Thirty-two patients with severe subarachnoid hemorrhage and undergoing aneurysm clipping were included into this single center, randomized, double-blind trial. Sixteen patients received NPRIs implanted into the basal cisterns in direct contact to the exposed proximal blood vessels; in 16 control patients, the basal cisterns were opened and washed out only without leaving implants. Angiography was performed preoperatively and at day 8+/-1. Computed tomography imaging was analyzed for the incidence of territorial infarcts unrelated to surgery. Patient outcome was assessed using the modified Rankin and National Institute of Health Stroke scales.

RESULTS

The incidence of angiographic vasospasm in proximal vessel segments was significantly reduced after implantation of NPRIs (73% control versus 7% NPRIs). Significant differences occurred also for the majority of distal vessel segments. Computed tomography scans revealed a lower incidence of delayed ischemic lesions (47% control versus 14% NPRIs). The NPRI group demonstrated more favorable modified Rankin and National Institute of Health Stroke scales as well as a significantly lower incidence of deaths (38% control versus 6% NPRIs).

CONCLUSIONS

Implantation of NPRIs reduces the incidence of cerebral vasospasm and delayed ischemic deficits and improves clinical outcome after severe subarachnoid hemorrhage.

Racial differences in cerebral vasospasm: a systematic review of the literature

OBJECTIVE

Despite a significant body of clinical research and the widespread use of early intervention with aggressive postoperative management, cerebral vasospasm (CV) continues to contribute significantly to the morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH). Many studies have evaluated predictive factors, although none to date has investigated a possible difference in the incidence of CV between Asian and white patients. We present a review of the modern aSAH literature to examine the incidence of CV in Japan and Europe, two highly researched populations.

METHODS

A literature search was performed using the Medline and PubMed databases. Studies conducted in Japan or Europe published between 1990 and 2004 that reported an incidence of CV after aSAH were subjected to a thorough review. Data from included studies were categorized by origin (Japan or Europe) and method of CV diagnosis (angiography, delayed ischemic neurological deficit, or new infarct attributable to CV), and then were combined. Recorded incidences then were compared using a chi test, and estimates of the relative risk of vasospasm were computed.

RESULTS

The initial literature search identified 102 studies, and 32 studies met all inclusion criteria. The incidence of vasospasm diagnosed by angiography, delayed ischemic neurological deficit, and computed tomography was significantly greater in Japanese studies (all P < 0.001). The relative risks for Japanese patients as compared with European patients were 2.04, 2.07, and 1.53 for angiographic CV, delayed ischemic neurological deficit, and new infarct, respectively.

CONCLUSION

Patients in Japanese studies were more likely to experience CV after aSAH across diagnostic methods. This may be a manifestation of genetic differences between Japanese and European populations. Clinicians should consider possible patient differences when interpreting CV research conducted in these populations.

Development of Drug Delivery System for Intrathecal Administration and Its Therapeutic Effect on Cerebral Vasospasm and Ischemia

To date, the pharmacologic approach to cerebral vasospasm and ischemia has been hampered in part by an inability to attain sufficiently high concentrations of drugs in the cerebrospinal fluid (CSF). To overcome this limitation of current drug therapy, we have developed a sustained-release preparation of the protein kinase inhibitor fasudil. Experimental cerebral vasospasm in rats and dogs was induced by double injection of autologous arterial blood into the cisterna magna. Focal cerebral ischemia in rats was induced by middle cerebral artery occlusion using an intraluminal suture technique. A single intrathecal injection of liposomal fasudil can maintain a therapeutic the drug concentration in the CSF due to the sustained-release property of liposomes, significantly decreasing intact size of acute ischemia and decreasing vasoconstriction of the basilar artery in cerebral vasospasm. This novel approach for the treatment of cerebral vasospasm and ischemia may have significant potential for use in the clinical setting.

Efficacy and safety of nicardipine prolonged-release implants for preventing vasospasm in humans

BACKGROUND AND PURPOSE

Despite extensive investigative efforts, there are few treatments that can prevent vasospasm after subarachnoid hemorrhage. This study was conducted to examine the efficacy and safety of nicardipine prolonged-release implants (NPRI) for humans, which have already been proven in dogs.

METHODS

Twenty consecutive subarachnoid hemorrhage patients with thick subarachnoid clot were treated with NPRI (a pellet of diameter 2 mm, length 10 mm, containing 4 mg of nicardipine) during surgery after clipping of their aneurysm. The number and location of pellets depended on the amount and site of subarachnoid clot on preoperative CT and on craniotomy.

RESULTS

Two to 10 pellets were implanted in the cistern of the internal carotid, middle cerebral, and/or anterior cerebral artery, where thick clots existed and therefore vasospasm related to delayed ischemic neurological deficits was highly likely. Delayed ischemic neurological deficits and cerebral infarctions were seen in 1 patient. Angiography performed on days 7 to 12 revealed no vasospasm in any arteries near which NPRI were placed. No complications were experienced.

CONCLUSIONS

Vasospasm was completely prevented for the arteries in thick clot cisterns, when NPRI were placed adjacent to the arteries during surgery. This drug-delivery system offers a promising approach for preventing vasospasm.

Efficacy of controlled-release papaverine pellets in preventing symptomatic cerebral vasospasm

OBJECT

Vasospasm as a complication of subarachnoid hemorrhage is a major concern in clinical practice. The systemic drugs in current use are of limited value. Topical, intrathecal, or intraarterial papaverine administered during surgical or angiographic procedures is a potent vasodilating drug; however, hypotension limits its systemic application. Local application of papaverine in a biodegradable controlled- or sustained-release matrix is proposed for vasospasm prophylaxis to be used in patients scheduled for aneurysm surgery.

METHODS

Controlled-release papaverine (PapaCR) drug pellets were prepared using the biodegradable aliphatic polyester poly(DL-lactide-co-glycolide) as the carrier matrix. In vitro tests were performed to determine drug kinetics. One hundred seventeen patients, 73 assigned to the control group and 44 assigned to the PapaCR-treated group, participated in this study. Patients who were deemed to be at high risk for the development of vasospasm were selected to participate in the study. During aneurysm surgery, drug pellets were placed in cisterns over arterial segments. In two patients, cerebrospinal fluid was sampled every 6 hours for the first 5 days through a lumbar catheter that had been inserted at the beginning of aneurysm surgery. The incidence of clinical vasospasm and Glasgow Outcome Scale scores in the patients were evaluated statistically. The results of in vitro studies showed that effective local concentrations of papaverine could be maintained for more than 10 days. The first-degree drug-release profile was demonstrated using this design. In clinical studies no adverse effects due to the drug were seen. The PapaCR effectively prevented development of clinical vasospasm. and outcome scores were significantly better in patients in the treated group.

CONCLUSIONS

Local application of controlled- or sustained-release papaverine can be safely used in preventing vasospasm.