Intracarotid slow bolus injection of nimodipine during angiography for treatment of cerebral vasospasm after SAH. A preliminary report

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

German Clinical Trial Register DRKS00030505.

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

Introduction

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

Research question

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

Material and methods

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

Results

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

Discussion and conclusion

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of Cilostazol on Delayed Cerebral Infarction in Aneurysmal Subarachnoid Hemorrhage Using Explainable Predictive Modeling

The studies interpreting DCI, a complication of SAH, and identifying correlations are very limited. This study aimed to investigate the effect of cilostazol on ACV and DCI after coil embolization for ruptured aneurysms (n = 432). A multivariate analysis was performed and explainable artificial intelligence approaches were used to analyze the contribution of cilostazol as a risk factor on the development of ACV and DCI with respect to global and local interpretation. The cilonimo group was significantly lower than the nimo group in ACV (13.5% vs. 29.3; p = 0.003) and DCI (7.9% vs. 20.7%; p = 0.006), respectively. In a multivariate logistic regression, the odds ratio for DCI for the cilonimo group, female sex, and aneurysm size was 0.556 (95% confidence interval (CI), 0.351-0.879; p = 0.012), 3.713 (95% CI, 1.683-8.191; p = 0.001), and 1.106 (95% CI, 1.008-1.214; p = 0.034). The risk of a DCI occurrence was significantly increased with an aneurysm size greater than 10 mm (max 80%). The mean AUC of the XGBoost and logistic regression models was 0.94 ± 0.03 and 0.95 ± 0.04, respectively. Cilostazol treatment combined with nimodipine could decrease the prevalence of ACV (13.5%) and DCI (7.9%) in patients with aSAH.

Calcium Antagonists in the Management of Patients with Aneurysmal Subarachnoid Hemorrhage: A Review

Cerebral arterial vasospasm and infarction is the leading cause of death and disability among patients who reach a major medical center after aneurysmal subarachnoid hemorrhage (SAH). Recent evidence suggests that two calcium antagonists, nimodipine or nicardipine, may be useful in preventing this important complication of SAH. This paper reviews the current status of these two calcium antagonists in the management of SAH.

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.

Aneurysmal Subarachnoid Hemorrhage and Vasospasm

Aneurysmal subarachnoid hemorrhage is potentially fatal and is associated with poor outcomes in many patients. Advances in neurosurgical and medical management of ruptured aneurysms have improved mortality rates in patients with aneurysmal subarachnoid hemorrhage. Surgical and endovascular interventions, such as external ventricular drain placement, aneurysm clipping, and endovascular coiling, have been developed over the past few decades. Patients with aneurysmal subarachnoid hemorrhage are also at risk for cerebral vasospasm and delayed cerebral ischemia. This article describes the diagnosis and treatment of aneurysmal subarachnoid hemorrhage, vasospasm, and cerebral ischemia. Concurrent medical considerations and ideas for future neuroinflammatory vasospasm research are also discussed.

Intra-arterial nimodipine for cerebral vasospasm after subarachnoid haemorrhage: Influence on clinical course and predictors of clinical outcome

Intra-arterial nimodipine (IAN) has shown a promising effect on cerebral vasospasm (CV) after aneurysmal subarachnoid haemorrhage. At our institution, Rigshospitalet, IAN treatment has been used since 2009, but the short- and long-term clinical efficacy of IAN has not yet been assessed. The purpose was to evaluate the efficacy and clinical outcome of IAN treatment of symptomatic CV, and to assess the predictors of clinical outcome. Medical records of 25 patients undergoing a total of 41 IAN treatment sessions were retrospectively reviewed. Data on angiographic results, blood-flow velocities and the clinical condition before and after the IAN treatment were recorded. Predictors of the clinical outcome were assessed with a linear regression model. Positive angiographic response was achieved in 95.1% of 41 IAN treatment sessions. Flow-velocity measurements showed no relationship with angiographic responses of IAN. The immediate clinical improvement was observed in three patients (12%). Five patients (20%) had a favourable outcome at discharge and at three-month follow-up; 10 patients (40%) had a moderate to poor outcome; and the rest (40%) died. Increased number of affected vessels and number of procedures carried out per patient, and a trend toward an increased delay time from symptomatic CV to confirming angiographic CV and thus instituting IAN treatment predicted the poor clinical outcome. IAN treatment appears to be effective in reversing angiographic CV. However, it is not always effective in reversing clinical deterioration, as several other factors including treatment delay affect the clinical course.

Continuous intra-arterial nimodipine infusion in patients with severe refractory cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a feasibility study and outcome results

BACKGROUND

Severe cerebral vasospasm is a major cause of death and disability in patients with aneurysmal subarachnoid hemorrhage. No causative treatment is yet available and hypertensive hypervolemic therapy (HHT) is often insufficient to avoid delayed cerebral ischemia and neurological deficits. We compared patients receiving continuous intra-arterial infusion of the calcium-antagonist nimodipine with a historical group treated with HHT and oral nimodipine alone.

METHODS

Between 0.5 and 1.2 mg/h of nimodipine were continuously administered by intra-arterial infusion via microcatheters either into the internal carotid or vertebral artery or both, depending on the areas of vasospasm. The effect was controlled via multimodal neuromonitoring and transcranial Doppler sonography. Outcome was determined by means of the Glasgow Outcome Scale at discharge and 6 months after the hemorrhage and compared to a historical control group.

RESULTS

Twenty-one patients received 28 intra-arterial nimodipine infusions. Six months after discharge, the occurrence of cerebral infarctions was significantly lower (42.6 %) in the nimodipine group than in the control group (75.0 %). This result was reflected by a significantly higher proportion (76.0 %) of patients with good outcome in the nimodipine-treated group, when compared to 10.0 % good outcome in the control group. Median GOS was 4 in the nimodipine group and 2 in the control group (p = 0.001).

CONCLUSIONS

Continuous intra-arterial nimodipine infusion is an effective treatment for patients with severe cerebral vasospasm who fail to respond to HHT and oral nimodipine alone. Key to the effective administration of continuous intra-arterial nimodipine is multimodal neuromonitoring and the individual adaptation of dosage and time of infusion for each patient.

Effects of intrathecal administration of nicardipine and nifedipine on chronic cerebral vasospasm in dogs

Chronic cerebral vasospasm after subarachnoid haemorrhage (SAH) responds poorly to systemic administration of dihydropyridine calcium antagonists. However, the spastic arteries can be dilated by the topical (intrathecal) administration of the drugs. We examined by angiography the spasmolytic effects of intrathecal (cisternal) administration of nicardipine (0.1 mg 1 ml ) or nifedipine (0.1 mg 1 ml ) on day 7 of SAH made by the two-haemorrhage model in dogs. Both drugs dilated the spastic basilar artery from 15 min till 4 hours after the drug administration. The increase in the diameter of the basilar artery between 1 and 3 hours was statistically significant in both groups. Intrathecal administration of nicardipine which is water soluble, may be useful in the treatment of chronic cerebral vasospasm in patients.

Nimodipine attenuation of early brain dysfunctions is partially related to its inverting acute vasospasm in a cisterna magna subarachnoid hemorrhage (SAH) model in rats

Subarachnoid hemorrhage (SAH)-induced brain injury is highly related to neurological deficits and mortality. Regional cerebral blood flow (rCBF) changes and vasoconstriction are two complications that occur soon after SAH experimentally. In this study we investigated the changes in rCBF and vertebro-basilar arterial diameter in a cisterna megna SAH model in Sprague-Dawley rats and intended to explore whether improving early rCBF reduction and cerebral vasospasm could contribute to alleviating blood-brain barrier (BBB) dysfunction. In rats for rCBF, vasospasm and BBB permeability assessments, nimodipine (NDP) or saline was administered intravenously 5 minutes after SAH. rCBF within the first 60 minutes after SAH was measured by laser Doppler flowmetry. BBB permeability indexed by Evans Blue extravasation was assessed 4 hours after SAH. Angiography for the caliber changes of the vertebro-basilar artery were conducted 30 minutes post SAH. Pronounced rCBF reduction and vasospasm were observed soon after SAH, followed by BBB permeability increment. NDP administration could improve rCBF and attenuate vasospasm, followed by the alleviation of BBB permeability. Our results demonstrate that early improvement of cerebral circulation by NDP may contribute to the reduction in brain injury indexed by BBB disruption.

Angiographic features and clinical outcomes of intra-arterial nimodipine injection in patients with subarachnoid hemorrhage-induced vasospasm

OBJECTIVE

The aim of this study was to determine the role of intra-arterial (IA) nimodipine injections for cerebral vasospasm secondary to ruptured subarachnoid hemorrhage (SAH) and to investigate the factors that influence vasodilation and clinical outcomes.

METHODS

We enrolled 29 patients who underwent aneurysm clipping for ruptured cerebral aneurysms between 2009 and 2011, and who received IA nimodipine after subsequently presenting with symptomatic vasospasm. The degree of vasodilation shown in angiography was measured, and the correlation between the degree of vasodilation and both the interval from SAH to cerebral vasospasm and the interval from clipping to cerebral vasospasm was determined. The change in blood flow rate after IA injection was assessed by transcranial Doppler ultrasound. Multiple clinical parameters were completed before and after IA nimodipine injection to evaluate any improvements in clinical symptoms.

RESULTS

For eight patients, Glasgow Coma Scale (GCS) scores increased by two or more points. The regression analysis demonstrated a positive correlation between the change in GCS scores after IA nimodipine injection and the change in blood vessel diameter (p=0.025). A positive correlation was also observed between the interval from SAH to vasospasm and the change in diameter (p=0.040); and the interval from clipping to vasospasm and the change in diameter (p=0.022).

CONCLUSION

IA nimodipine injection for SAH-induced vasospasm led to significant vasodilation in angiography and improvement in clinical symptoms without significant complications. Our findings suggest that IA nimodipine injection should be utilized when intractable vasospasm develops despite rigorous conservative management.

Continuous Local Intra-arterial Nimodipine Administration in Severe Symptomatic Vasospasm After Subarachnoid Hemorrhage

BACKGROUND:

Cerebral vasospasm (CV) is a potentially disastrous consequence of subarachnoid hemorrhage despite medical treatment. Nimodipine is a potent drug for vessel relaxation, but side effects may preclude a sufficient dose.

OBJECTIVE:

To explore whether continuous local intra-arterial nimodipine administration (CLINA) can reverse vasospasm and prevent delayed ischemic neurological deficit.

METHODS:

Six consecutive subarachnoid hemorrhage patients (5 women; mean age, 47.2 years) with severe CV despite maximum medical therapy underwent CLINA within 2 hours after the onset of clinical symptoms. After anticoagulation, microcatheters were inserted distally in the concerning supra-aortic vessels. Glyceryl trinitrate injection (2 mg) was followed by CLINA (nimodipine 0.4 mg/h for 70-147 hours). Duration of CLINA was determined by neurological status, transcranial Doppler sonography, and partial tissue oxygen pressure values.

RESULTS:

In all patients, neurological deficits improved or partial tissue oxygen pressure values returned to normal and transcranial Doppler sonography confirmed a reduced blood flow velocity within 12 hours. Magnetic resonance imaging showed no ischemic lesion caused by CV. Neurological outcome was good (modified Rankin Scale score, 0–2) in 3 patients, whereas 1 patient had a moderate clinical outcome (modified Rankin Scale score, 3–4) and 2 patients had a poor outcome (modified Rankin Scale score, 5) because of the SAH.

CONCLUSION:

Preliminary data show that CLINA is a straightforward, effective, and safe option for patients with severe CV refractory to medical therapy. Dilation of spastic arteries starts within a few hours and is lasting. Indication for CLINA is peripheral and diffuse CV at any location.

Safety and efficacy of transluminal balloon angioplasty using a compliant balloon for severe cerebral vasospasm after an aneurysmal subarachnoid hemorrhage

OBJECTIVE

Vasospasm of cerebral vessels remains a major source of morbidity and mortality after an aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to evaluate the safety and efficacy of transluminal balloon angioplasty (TBA) for SAH-induced vasospasm.

METHODS

Eleven patients with an angiographically confirmed significant vasospasm (>50% vessel narrowing and clinical deterioration) were studied. A total of 54 vessel segments with significant vasospasm were treated by TBA. Digital subtraction angiography was used to confirm the presence of vasospasm, and TBA was performed to dilate vasospastic arteries. Medical and angiographic reports were reviewed to determine technical efficacy and for procedural complications.

RESULTS

TBA using Hyper-Glide or Hyper-Form balloons (MicroTherapeutics, Irvine, CA) was successfully accomplished in 88.9% vasospastic segments (48 of 54), namely, in the distal internal carotid artery (100%, n=7), the middle cerebral artery (100%), including the M1 (n=10), M2 (n=10), and M3 segments (n=4), in the vertebral artery (100%, n=2), basilar artery (100%, n=1), and in the anterior cerebral artery (ACA), including the A1 (66%), A2 (66%), and A3 segments (100%). Vessel diameters significantly increased after TBA. There were no cases of vessel rupture or thromboembolic complications. GCS at one day after TBA showed an improvement in all patients except one.

CONCLUSION

This study suggests that TBA using Hyper-Glide or Hyper-Form balloons is a safe and effective treatment for subarachnoid hemorrhage-induced cerebral vasospasm.

Intraarterial nimodipine infusion to treat symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Cerebral vasospasm leading to cerebral ischemic infarction is a major cause of morbidity and mortality in the patients who suffer with aneurysmal subarachnoid hemorrhage. Despite adequate treatment, some patients deteriorate and they develop symptomatic vasospasm. The objective of the present study was to investigate the efficacy and clinical outcome of intraarterial nimodipine infusion on symptomatic vasospasm that is refractory to hemodynamic therapy.

METHODS

We retrospectively reviewed the procedure reports, the clinical charts and the transcranial doppler, computed tomography and digital subtraction angiography results for the patients who underwent endovascular treatment for symptomatic cerebral vasospasm due to aneurysmal SAH. During the 36 months between Jan. 2005 and Dec. 2007, 19 patients were identified who had undergone a total of 53 procedures. We assessed the difference in the arterial vessel diameter, the blood flow velocity and the clinical outcome before and after these procedures.

RESULTS

Vascular dilatation was observed in 42 of 53 procedures. The velocities of the affected vessels before and after procedures were available in 33 of 53 procedures. Twenty-nine procedures exhibited a mean decrease of 84.1 cm/s. We observed clinical improvement and an improved level of consciousness with an improved GCS score after 23 procedures.

CONCLUSION

Based on our results, the use of intraarterial nimodipine is effective and safe in selected cases of vasospasm following aneurysmal SAH. Prospective, randomized studies are needed to confirm these results.

ANGIOGRAPHIC AND HEMODYNAMIC EFFECT OF HIGH CONCENTRATION OF INTRA-ARTERIAL NICARDIPINE IN CEREBRAL VASOSPASM

OBJECTIVE

Nicardipine has been used to treat cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. Intra-arterial (IA) infusion of high concentrations of nicardipine decreases procedure time, but it may affect hemodynamic parameters. In addition, a quantitative measurement of improvement of vessel diameter on the angiograms has not been performed.

METHODS

We conducted a single-center, retrospective database analysis of consecutive patients with symptomatic vasospasm after aneurysmal subarachnoid hemorrhage who failed medical management and received IA nicardipine between September 2005 and June 2006. Nicardipine (1 mg/mL/min) was infused intra-arterially by microcatheter. Blood pressure, heart rate, and intracranial pressure were recorded during the infusion. The effect of IA nicardipine on the vessel's diameter was measured on angiography by two blinded investigators.

RESULTS

Forty-six treatment sessions were performed in 22 consecutive patients (13 women; age, 56.4 ±13 years). Fourteen patients received IA nicardipine alone, and 8 patients had additional angioplasty. The average nicardipine dose was 12 ± 10 mg (range, 2–25 mg). The mean decrease of systolic, diastolic, and mean blood pressure was 17.4 ± 18.3 mm Hg, 7.7 ± 10.4 mm Hg, and 10.9 ± 11.6 mm Hg, respectively. There was no change in intracranial pressure. Measurement of 49 vessels in the 14 patients treated with nicardipine alone showed a significant increase in arterial diameters (range, 1–74%; P &lt; 0.0001). At the time of discharge, 11 patients (50%) were functionally independent (modified Rankin Scale score, 0–2).

CONCLUSION

High concentrations of IA nicardipine infusion have a reversible effect on blood pressure and heart rate. IA nicardipine results also in a significant improvement in vessel diameter in patients with vasospasm after aneurysmal subarachnoid hemorrhage.

Intra-arterial nimodipine to treat symptomatic cerebral vasospasm following traumatic subarachnoid haemorrhage. Technical case report

Intra-arterial Nimodipine administration can be an effective alternative to papaverine or balloon angioplasty for the treatment of cerebral vasospasm refractory to medical therapy. It has been used for intractable vasospasm due to aneurysmal subarachnoid haemorrhage (SAH) with convincing results and no significant complications in small case series. This report describes of a patient with symptomatic and angiographically documented vasospasm following traumatic SAH which was refractory to maximal medical therapy and successfully treated with intra-arterial infusion of Nimodipine. This first reported technical note is with special reference to the nimodipine administration modalities, clinical and neuroradiological criteria of selection as well as the follow up of the patient.

Intra-arterial nimodipine for severe cerebral vasospasm after aneurysmal subarachnoid hemorrhage: influence on clinical course and cerebral perfusion

BACKGROUND AND PURPOSE

The efficacy of intra-arterial administration of nimodipine (IAN) in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (SAH) remains unproved. The goal of the present study was to investigate the clinical effect and cerebral perfusion after IAN in patients with severe vasospasm refractory to hemodynamic treatment.

MATERIALS AND METHODS

Twenty-six of 214 patients with aneurysmal SAH were included in the prospective study, approved by the local ethics committee. All patients met the criteria of medically refractory cerebral vasospasm. Effectiveness was monitored angiographically by digital subtraction angiography and by transcranial Doppler (TCD), perfusion CT (PCT), and neurologic examination during treatment course and follow-up.

RESULTS

No angiographic effect was observed in 8 patients. The pooled PCT values revealed a reduction of time to peak (P = .03) and mean transit time (P = .17) 1 day after intervention. This effect did not persist during the following days. The pooled TCD analysis demonstrated a transient increase in flow 1 day after intervention (P = .03). No trend was evident during the next 7 days after intervention. Additional infarction was experienced by 61.1% of patients.

CONCLUSIONS

IAN in a selective patient group resulted in a positive response with reduction of angiographic vasospasm and increase in cerebral perfusion as detected by PCT after 24 hours. Therefore, IAN appears more effective than intra-arterial papaverine. Nevertheless the efficacy of IAN is temporary. Therefore, the search for more effective treatment strategies to reduce critical vasospasm and to improve cerebral perfusion must be continued.

Blood blister-like aneurysms of the internal carotid artery trunk causing subarachnoid hemorrhage: treatment and outcome

OBJECT

The object of this study was to evaluate cases of subarachnoid hemorrhage (SAH) from ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA) trunk.

METHODS

The authors performed a single-center, retrospective study. Data analyzed were patient age, sex, Hunt and Hess grade, Fisher grade, time from SAH to hospitalization, aneurysm size and location, collateral capacity of the circle of Willis, time from hospitalization to aneurysm repair, type of aneurysm repair, complications, and Glasgow Outcome Scale (GOS) score at follow-up.

RESULTS

A total of 211 patients suffered SAH from ICA aneurysms. Of these, 14 patients (6.6%) had ICA trunk BBAs; 6 men and 8 women. The median age was 47.8 years (range 29.9-67.7 years). The Hunt and Hess grade was IV or V in 7 cases, and SAH was Fisher Grade 3 + 4 in 6. All aneurysms were small (< 1 cm), without relation to vessel bifurcations, and usually located anteromedially on the ICA trunk. Three patients were treated with coil placement and 11 with clip placement. Of the 7 patients in whom the ICA was preserved, only 1 had poor outcome (GOS Score 2). In contrast, cerebral infarcts developed in all patients treated with ICA sacrifice, directly postoperatively in 2 and after delay in 5. Six patients died, 1 survived in poor condition (GOS Score 3; p < 0.001).

CONCLUSIONS

Internal carotid BBAs are rare, small, and difficult to treat endovascularly, with only 2 of 14 patients successfully treated with coil placement. The BBAs rupture easily during surgery (ruptured in 6 of 11 surgical cases). Intraoperative aneurysm rupture invariably led to ICA trap ligation. Sacrifice of the ICA within 48 hours of an SAH led to very poor outcome, even in patients with adequate collateral capacity on preoperative angiograms, probably because of vasospasm-induced compromise of the cerebral collaterals.

Intravenous magnesium versus nimodipine in the treatment of patients with aneurysmal subarachnoid hemorrhage: a randomized study

OBJECTIVE

The prophylactic use of nimodipine in patients with aneurysmal subarachnoid hemorrhage reduces the risk of ischemic brain damage. However, its efficacy seems to be rather moderate. The question arises whether other types of calcium antagonists offer better protection. Magnesium, nature's physiological calcium antagonist, is neuroprotective in animal models, promotes dilatation of cerebral arteries, and has an established safety profile. The aim of the current pilot study is to evaluate the efficacy of magnesium versus nimodipine to prevent delayed ischemic deficits after aneurysmal subarachnoid hemorrhage.

METHODS

One hundred and thirteen patients with aneurysmal subarachnoid hemorrhage were enrolled in the study and were randomized to receive either magnesium sulfate (loading 10 mg/kg followed by 30 mg/kg daily) or nimodipine (48 mg/d) intravenously until at least postoperative Day 7. Primary outcome parameters were incidence of clinical vasospasm and infarction. Secondary outcome measures were the incidence of transcranial Doppler/angiographic vasospasm, the neuronal markers (neuron-specific enolase, S-100), and the patients' Glasgow Outcome Scale scores at discharge and after 1 year.

RESULTS

One hundred and four patients met the study requirements. In the magnesium group (n = 53), eight patients (15%) experienced clinical vasospasm and 20 (38%) experienced transcranial Doppler/angiographic vasospasm compared with 14 (27%) and 17 (33%) patients in the nimodipine group (n = 51). If clinical vasospasm occurred, 75% of the magnesium-treated versus 50% of the nimodipine-treated patients experienced cerebral infarction resulting in fatal outcome in 37 and 14%, respectively. Overall, the rate of infarction attributable to vasospasm was virtually the same (19 versus 22%). There was no difference in outcome between groups.

CONCLUSION

The efficacy of magnesium in preventing delayed ischemic neurological deficits in patients with aneurysmal subarachnoid hemorrhage seems to be comparable with that of nimodipine. The difference in their pharmacological properties makes studies on the combined administration of magnesium and nimodipine seem promising.

The prophylactic use of transluminal balloon angioplasty in patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study

OBJECT

Recent advances in neuroradiology have made it possible to dilate vasospastic human cerebral arteries after aneurysmal subarachnoid hemorrhage (SAH), but the time window is short and the success rate for reversal of delayed ischemic neurological deficits (DINDs) varies between 31% and 77%. In a dog model of vasospasm, transluminal balloon angioplasty (TBA) performed on Day 0 totally prevented the development of angiographically demonstrated narrowing on Day 7. Because the effect of preventive TBA in this animal model was better than any pharmacological treatment described previously for experimental vasospasm, the authors conducted a pilot trial in humans to assess the safety and efficacy of TBA performed within 3 days of SAH.

METHODS

The study group consisted of 13 patients with Fisher Grade 3 SAH who had a very high probability of developing vasospasm. In all patients, regardless of the site of the ruptured aneurysm, target vessels for prophylactic TBA were as follows: the internal carotid artery, A1 segment, M1 segment, and P1 segment bilaterally; the basilar artery; and one vertebral artery. Prophylactic TBA was considered satisfactory when it could be performed in at least two of the three parts of the intracranial circulation (right and/or left carotid system and/or vertebrobasilar system), and included the aneurysm-bearing part of the circulation. Of the 13 patients, none developed a DIND or more than mild vasospasm according to transcranial Doppler ultrasonography criteria. At 3 months posttreatment eight patients had made a good recovery, two were moderately disabled, and three had died; one patient died because of a vessel rupture during TBA and two elderly individuals died of medical complications associated with poor clinical condition on admission.

CONCLUSIONS

Compared with large series of patients with aneurysmal SAH reported in the literature, the results of this pilot study indicate an extremely low incidence of vasospasm and DIND after treatment with prophylactic TBA. A larger randomized study is required to determine whether prophylactic TBA is efficacious enough to justify the risks, and which vessels need to be dilated prophylactically.

Safety and efficacy of transluminal balloon angioplasty in the prevention of vasospasm in patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study

Recent advances in neuroradiology have made it possible to dilate human cerebral arteries that show vasospasm following aneurysmal subarachnoid hemorrhage (SAH), but the time window is short and the success rate for reversal of delayed ischemic neurological deficit (DIND) varies between 31% and 77%. In a canine model of vasospasm, transluminal balloon angioplasty (TBA) performed on Day 0 (the day of aneurysm rupture) has been shown to completely prevent the development of angiographically demonstrated narrowing by Day 7; this effect is better than any pharmacological treatment for vasospasm thus far described.

The authors conducted a pilot trial to assess the safety and efficacy of TBA performed within 3 days post-SAH. Twelve patients with a very high probability of developing vasospasm (Fisher Grade 3) were included. Target vessels for prophylactic TBA were the internal carotid artery, A1 segment, M1 segment, and P1 segment bilaterally, the basilar artery, and the vertebral artery.

No patient developed DIND or more than mild vasospasm, according to transcranial Doppler criteria. At 3 months, seven patients made a good recovery, two patients were moderately disabled, and three patients died; one patient died because of a vessel rupture during TBA and two older patients died of medical complications associated with an already poor clinical condition at admission.

Compared with the results of large series reported in literature of patients with aneurysmal SAH, the results of this pilot study indicate an extremely low incidence of vasospasm and DIND after patients underwent prophylactic TBA. A larger, randomized study, however, is required to determine whether prophylactic TBA is efficacious enough to justify the risks.

Does nimodipine influence sex difference in outcome after aneurysmal subarachnoid haemorrhage?

Before nimodipine was introduced as a standard treatment in patients with aneurysmal subarachnoid haemorrhage (SAH) females had a significantly poorer outcome which might be due to a higher frequency of delayed cerebral ischaemia (DCI). We evaluated the overall outcome with regard to gender in 188 consecutive patients with a verified ruptured intracranial aneurysm treated with nimodipine. The only significant differences concerning prognostic factors between the sexes were a higher frequency of SAH at the primary CT in female (p < 0.05) and a higher frequency of middle cerebral artery aneurysms in females (p < 0.01). These factors affect the outcome in females unfavourably. However, contrary to previous studies, we found no difference in overall outcome after three months between the sexes in this clinical material. Our observation can be explained by a positive effect of nimodipine on DCI.

Effects of a hydroxyl radical scavenger on delayed ischemic neurological deficits following aneurysmal subarachnoid hemorrhage: results of a multicenter, placebo-controlled double-blind trial

A water-soluble, novel synthetic compound, AVS ((+/-)-N, N'-propylenedinicotinamide; nicaraven) has no demonstrable vasoactive properties but scavenges hydroxyl radicals in aqueous environmental conditions at neutral pH. Based on the results of preceding experimental and clinical studies showing marked ameliorative effects of AVS on cerebral vasospasm and ischemic brain damage, a multicenter, placebo-controlled double-blind clinical trial was undertaken to verify its beneficial effects on delayed ischemic neurological deficits (DINDs) due to vasospasm and on the overall outcome of patients with subarachnoid hemorrhage (SAH). A total of 162 patients with SAH who had Glasgow Coma Scale scores between 7 and 15 on admission were enrolled in the trial. Drug administration (4 g AVS or 4 g glucose as placebo; infused intravenously for 6-8 hours once a day) was begun within 5 days post-SAH and continued for 10 to 14 days. Intent-to-treat analysis of these patients revealed that the overall incidence of DINDs, which was defined as an exacerbation of impaired consciousness and/or focal neurological deficits, was significantly reduced, by 34.5% (placebo 54.2%, AVS 35.5%; p < 0.05, Mann-Whitney U-test). The Glasgow Outcome Scale (GOS) score at 1 month was significantly improved by AVS (p < 0.05, U-test). At 3 months, the difference in the GOS scores between the groups became marginal on U-tests (p < 0.10), but the percentage of good outcome tended to increase, with a relative increase of 20.3% (AVS 76.3%, placebo 63.4%; p < 0.10, chi-square test), and the cumulative incidence of death was significantly reduced (p < 0.05, log-rank test). No significant adverse reaction attributable to treatment was observed. the usefulness of AVS in therapy for SAH is strongly indicated by the fact that the agent significantly ameliorated DINDs, leading to a marked improvement in the GOS scores at 1 month, as well as a reduction in the cumulative incidence of death by 3 months.

The effect of nimodipine on autoregulation of cerebral blood flow after subarachnoid haemorrhage in rat

Disturbance of the autoregulation of the cerebral blood flow (CBF) is frequently seen following subarachnoid haemorrhage (SAH) and is possibly partly caused by cerebral ischaemia. It is well-known, that the calcium channel blocker nimodipine reduces the incidence of cerebral infarction and ischaemic dysfunction after SAH. The aim of the present study was to investigate the effect of nimodipine on autoregulation of CBF in an experimental model of SAH. The autoregulation was investigated in 10 control rats with SAH and in 10 nimodipine treated rats with SAH by serial measurements of CBF using a 133Xenon intracarotid injection method during controlled blood pressure manipulations. In the control rats the autoregulation was severely disturbed, no plateau was found where CBF was independent of changes in the arterial blood pressure (MABP). In rats treated with intravenous nimodipine (0.03 mg/kg body weight/h), CBF was 33.0% higher and MABP 5.3% higher compared with the controls. CBF was found constant in the MABP interval between 60 and 100 mmHg which indicates, that nimodipine improves the autoregulation of CBF after SAH.

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

Calcium antagonists are currently most widely used for chronic cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH). However, the vasodilatory effects of systemically administered calcium antagonists can be limited secondary to hypotension. We previously compared intrathecal and intravenous routes of administration of nicardipine. Intrathecal administration of nicardipine significantly dilated spastic basilar arteries on day 7 in a two-haemorrhage canine model of vasospasm. In the present communication, the effects of prophylactic, serial administration of intrathecal nicardipine on vasospasm was examined in 50 patients. Patients were classified as Fisher SAH group 3 and all had their aneurysms clipped within 3 days of SAH. Following placement of a cisternal drain, 2 mg of nicardipine was injected, three times each day for an average of 10 days. The control group consisted of 91 similar patients with cisternal drainage not treated with nicardipine. Intrathecal administration of nicardipine decreased the incidence of symptomatic vasospasm by 26%, angiographic vasospasm by 20% and increased good clinical outcome at one month after the haemorrhage by 15%. Postoperative angiograms revealed that patients in the nicardipine group showed less vasospasm of major cerebral arteries, near the tip of a drain in the basal cistern, but vasospasm in the A2 and M2 segments was not decreased. Radio-isotope cisternography suggested that nicardipine might not reach the subarachnoid space around A2 and M2 segments. Nine patients complained of headache probably secondary to nicardipine induced vasodilation. Two patients suffered from meningitis, both were successfully treated. Intrathecal administration nicardipine appears to be effective in the treatment of vasospasm, but side effects were significant.

Effects of HA1077, an intracellular calcium antagonist, on neurotransmitter metabolism in rat brain in vivo

The effect of HA1077, an intracellular calcium antagonist, on neurotransmitter metabolism in rat brain was investigated in vivo. After administration of HA1077, at doses of 0.1, 0.3, and 3 mg/kg, 5-hydroxyindoleacetic acid (5-HIAA) levels increased in most regions except midbrain. In the striatum, parallel increases of both serotonin (5-HT) and 5-HIAA levels were observed at 0.3 mg/kg, but only the 5-HT level increased at 0.1 mg/kg. These results suggest that HA1077 may activate the turnover or synthesis of 5-HT. After administration of HA1077 at 0.3, 1, and 3 mg/kg, the dopamine (DA) level was increased in the striatum, but 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid levels were unchanged. After HA1077 administration at 1 mg/kg, both DA and DOPAC levels increased in the hypothalamus and only DA level increased in the cerebral cortex. By contrast, DOPAC level decreased in the midbrain after HA1077 treatment at 0.1 and 0.3 mg/kg, and in the brainstem at 0.1 and 10 mg/kg. The ratio of [3H]-N-methylspiperone accumulation relative to that in the cerebellum did not change after HA1077 treatment at any of the doses employed. Thus, the effects of HA1077 on neurotransmitter metabolism are complex and vary depending on the dosage and sites of the brain. Although the dose-dependent effects of HA1077 on neurotransmitter metabolism are similar to those of calcium entry blockers, HA1077 can facilitate DA synthesis in the hypothalamus and striatum, unlike the calcium entry blockers.

Possible role of protein kinase C-dependent smooth muscle contraction in the pathogenesis of chronic cerebral vasospasm

In the present study, we investigate the possible role of protein kinase C (PKC)-dependent smooth muscle contraction in cerebral vasospasm following subarachnoid hemorrhage (SAH), employing the beagle "two-hemorrhage" model. The occurrence of chronic vasospasm was angiographically confirmed on day 7 in the basilar artery, which was exposed via the transclival approach. The artery was superfused with aerated Krebs-Henseleit solution containing various agents, and the subsequent changes in the basilar artery diameter were recorded by successive angiography. The preexisting spasm was not ameliorated by local application of neurotransmitter antagonists (atropine, methysergide, phentolamine, and diphenhydramine), calmodulin inhibitors (R24571 and W-7), or a calcium antagonist, nicardipine. However, the application of PKC inhibitors such as H-7 and staurosporine induced significant dilation of the artery. In another experiment, an intrinsic PKC activator, 1,2-diacylglycerol (DAG), in the basilar artery, the CSF, and the cisternal clot of beagles exposed to two hemorrhages was measured on days 1, 2, 4, 7, and 14 using the DAG kinase method. On days 2, 4, and 7, the DAG content of the basilar artery showed a significant and prolonged increase (150-190% of control), whereas it was unchanged on days 1 and 14. Throughout the experimental period, there was a significant linear correlation between the DAG content and the angiographical diameter of the basilar artery. The above results indicate that SAH leads to an increase in the DAG level within the cerebral artery through an as yet unknown mechanism and that subsequent activation of the PKC-dependent contractile system participates in the occurrence of chronic vasospasm.

Effect of nimodipine on platelet function in patients with subarachnoid hemorrhage

We studied platelet function in 41 patients with subarachnoid hemorrhage who were randomized to receive either nimodipine or placebo in a double-blind fashion. Nimodipine was given to 21 patients, intravenously for 7-10 days and then orally until 21 days after the subarachnoid hemorrhage. The other 20 patients received placebo in a similar manner. Nimodipine did not significantly influence platelet aggregability. For the first 1-5 days after the subarachnoid hemorrhage, nimodipine treatment did not have any notable effect on adenosine diphosphate-induced platelet thromboxane B2 release, but a significant (p less than 0.05) inhibitory effect was observed thereafter. During intravenous administration, nimodipine prevented the increase in thromboxane release otherwise observed after subarachnoid hemorrhage. Concomitant with the decrease in thromboxane release, nimodipine increased the platelet count both before and after surgery so that the capacity for thromboxane formation per liter of blood decreased less than expected on the basis of thromboxane release per 10(7) platelets. Our study suggests that nimodipine might diminish the chance of cerebral ischemia by inhibiting platelet thromboxane release.

Nimodipine has no effect on the cerebral circulation in conscious pigs, despite an increase in cardiac output

1. We studied the effects of four doses of nimodipine (0.5, 1, 2 and 4 micrograms kg-1 min-1) on systemic haemodynamics and on regional vascular beds, in particular the cerebral circulation, in conscious pigs. 2. Nimodipine caused dose-dependent, probably reflex-mediated, increases in heart rate (42% with the highest dose) and cardiac output (54%), while arterial blood pressure was only minimally affected. Left ventricular end-diastolic pressure and systemic vascular resistance decreased dose-dependently (35-40% at the highest dose) while stroke volume remained unchanged. 3. Total brain blood flow was not affected by the drug. Furthermore, we could not demonstrate any regional cerebral differences, as blood flows to both cerebral hemispheres as well as the diencephalon, cerebellum and brain stem remained unchanged. 4. Blood flow to the kidneys, liver, small intestine and skin also did not change. Nimodipine caused dose-dependent increases in blood flow to the stomach (95%), myocardium (97%) and adrenal glands (102%), while blood flow to skeletal muscles (267%) increased most. 5. It is concluded that in the conscious pig, nimodipine is an arterial vasodilator which shows some selectivity for the skeletal muscle vasculature but does not increase total or regional cerebral blood flow.

Nimodipine in the treatment of subarachnoid hemorrhage

Nimodipine, a calcium-channel antagonist with a relatively selective vasodilatory effect on cerebral blood vessels, has recently been approved for improvement of neurologic deficits due to spasm following subarachnoid hemorrhage. Nimodipine has low oral bioavailability (2.7-27.9 percent), a short half-life (2 h), is highly protein bound (98-99 percent), and is hepatically metabolized. Clinical studies have evaluated topical, intravenous, and oral administration of nimodipine for the treatment of cerebral artery spasm associated with subarachnoid hemorrhage. These studies document some benefit of the drug in reducing the occurrence of severe neurologic deficit, although this effect is not universal. Few adverse effects have been noted. Further studies are necessary to evaluate the pharmacologic and pharmacokinetic characteristics, the appropriate dose and route of administration, adverse effects, drug interactions, and the therapeutic efficacy of nimodipine before routine use can be recommended.

Effect of oral nimodipine on cerebral infarction and outcome after subarachnoid haemorrhage: British aneurysm nimodipine trial

OBJECTIVE

To determine the efficacy of oral nimodipine in reducing cerebral infarction and poor outcomes (death and severe disability) after subarachnoid haemorrhage.

DESIGN

Double blind, placebo controlled, randomised trial with three months of follow up and intention to treat analysis. To have an 80% chance with a significance level of 0.05 of detecting a 50% reduction in an incidence of cerebral infarction of 15% a minimum of 540 patients was required.

SETTING

Four regional neurosurgical units in the United Kingdom.

PATIENTS

In all 554 patients were recruited between June 1985 and September 1987 out of a population of 1115 patients admitted with subarachnoid haemorrhage proved by the results of lumbar puncture or computed tomography, or both. The main exclusion criterion was admission to the neurosurgical units more than 96 hours after subarachnoid haemorrhage. There were four breaks of code and no exclusions after entry. One patient was withdrawn and in 130 treatment was discontinued early. All patients were followed up for three months and were included in the analysis, except the patient who had been withdrawn.

INTERVENTIONS

Placebo or nimodipine 60 mg was given orally every four hours for 21 days to 276 and 278 patients, respectively. Treatment was started within 96 hours after subarachnoid haemorrhage.

END POINTS

Incidence of cerebral infarction and ischaemic neurological deficits and outcome three months after entry.

MEASUREMENTS

Demographic and clinical data, including age, sex, history of hypertension and subarachnoid haemorrhage, severity of haemorrhage according to an adaptation of the Glasgow coma scale, number and site of aneurysms on angiography, and initial findings on computed tomography were measured at entry. Deterioration, defined as development of a focal sign or fall of more than one point on the Glasgow coma scale for more than six hours, was investigated by using clinical criteria and by computed tomography, by lumbar puncture, or at necropsy when appropriate. All episodes of deterioration and all patients with a three month outcome other than a good recovery were assessed by a review committee.

MAIN RESULTS

Demographic and clinical data at entry were similar in the two groups. In patients given nimodipine the incidence of cerebral infarction was 22% (61/278) compared with 33% (92/276) in those given placebo, a significant reduction of 34% (95% confidence interval 13 to 50%). Poor outcomes were also significantly reduced by 40% (95% confidence interval 20 to 55%) with nimodipine (20% (55/278) in patients given nimodipine v 33% (91/278) in those given placebo).

CONCLUSIONS

Oral nimodipine 60 mg four hourly is well tolerated and reduces cerebral infarction snd improves outcome after subarachnoid haemorrhage.

Nimodipine treatment in poor-grade aneurysm patients. Results of a multicenter double-blind placebo-controlled trial

A multicenter, randomized placebo-controlled double-blind trial of nimodipine in poor-grade aneurysm patients was carried out in 17 Canadian hospitals. Of 188 patients enrolled in the trial, 32 were excluded for protocol violations and two were excluded due to statistical considerations, leaving 154 patients for valid outcome analysis. Nimodipine treatment was associated with a significantly better outcome (p less than 0.001): 21 (29.2%) of 72 nimodipine-treated patients had a good outcome at 3 months after subarachnoid hemorrhage (SAH) compared to eight (9.8%) of 82 placebo-treated patients. Delayed ischemic deficits from vasospasm alone were significantly less frequent in the nimodipine group (p less than 0.05) with permanent deficits occurring in five nimodipine-treated patients (6.9%) and in 22 placebo-treated patients (26.8%). Improvement in the good outcome rate and reduction in delayed ischemic deficits from vasospasm alone occurred in both Grade 3 and 4 patients, with no difference between nimodipine- and placebo-treated patients being found in Grade 5 patients. Repeat angiography after Day 4 was carried out in 124 patients. There was no significant difference in the incidence of moderate or severe diffuse spasm, which was seen in 64.3% of nimodipine-treated patients and 66.2% of placebo-treated patients. The authors conclude that nimodipine treatment in poor-grade patients with SAH results in an increase in the number of good outcomes and a reduction in the incidence of delayed neurological deterioration due to vasospasm. This effect occurs by a mechanism other than prevention of large-vessel spasm as visualized on angiography.

The effects of an intracellular calcium antagonist HA 1077 on delayed cerebral vasospasm in dogs

The effectiveness of calcium antagonists on a chronic cerebral vasospasm after an SAH is still under debate. Calcium channel blockers such as nimodipine, nifedipine etc. can dilate spastic arteries by intrathecal administration, but not by systemic (iv or po) use. HA 1077 is a novel and potent calcium antagonist vasodilator which is considered to act by employing different mechanisms from the usual calcium channel blockers since it inhibits 1. calcium ionophore A 23187 induced contraction in arterial strips and 2. phenylephrine induced contraction in calcium free media, suggesting that its site of action is in the intracellular space. HA 1077 is water soluble and relatively stable in light. In the present study, the efficacy of HA 1077 was evaluated on dogs by using the spiral arterial strips in vitro and by angiography in vivo. In the arterial strips from the control dogs, a 50% relaxation of KCl (15 mM) induced contraction was obtained by a 10(-6) M HA 1077 for the "intracranial" basilar and middle cerebral arteries, while a 10(-5) M was needed to obtain the same effect for the "extracranial" common carotid and vertebral arteries, indicating that HA 1077 is more effective for the intracranial arteries. A vasospasm was produced by the "two haemorrhage" model of Varsos et al. The average angiographic diameter of the basilar artery was reduced to 60% of the control on SAH day 7. Intravenous infusion of HA 1077 (0.5-3 mg/kg/30 min) significantly dilated the spastic basilar artery (up to 20-30%), for over 2 hours. A fall in the systemic BP remained less than 20% during this time.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of the calcium antagonist NB-818 on cerebral blood flow

The effects of intravenous injection of NB-818, isopropyl methyl 2-carbamoyloxymethyl-6-methyl-4-(2,3-dichlorophenyl)-1,4-dihydropyridine-3,5- dicarboxylate, on regional cerebral blood flow were studied in rabbits and Rhesus monkeys, using the hydrogen clearance technique. The above effects were compared with those of nicardipine and nimodipine. In rabbits, NB-818 (10 micrograms/kg i.v.) increased both cerebral cortical blood flow (rCBF) and cerebellar cortical blood flow by about 80% of the predrug level with a moderate decrease in mean arterial blood pressure, and no increase in skeletal muscle blood flow. The increase in cerebral blood flow with NB-818 was as great as that with nicardipine or nimodipine. In Rhesus monkeys, NB-818 (10-20 micrograms/kg i.v.) increased rCBF by about 30% of the predrug level, and its effect continued 30-60 min after dosing. The increase in rCBF with NB-818 was greater than that with nicardipine. The results from the present study indicate that NB-818 predominantly increases rCBF with a concomitant moderate hypotension, and its action is greater than that of nicardipine or nimodipine.

Effect of hypoxia on the contractile response to KCl, prostaglandin F2 alpha, and hemoglobin

The purpose of this experiment was to evaluate the effect of hypoxia on the in vitro contractile responses of canine basilar artery to KCl, prostaglandin (PG) F2 alpha, and hemoglobin. Hypoxia was induced by changing the bubbling gas mixture in the chamber from 95% O2/5% CO2 to 95% N2/5% CO2. Hypoxia augmented the contractile response developed at 95% O2 to 25 mM and 50 mM KCl, 3 X 10(-7) M and 10(-5) M PGF2 alpha, and 10(-6) M hemoglobin. No significant alteration of the hypoxic augmentation in any preparation exposed to 25 mM KCl, 3 X 10(-7) M PGF2 alpha, or 10(-6) M hemoglobin was observed with guanethidine (10(-5) M), prazosin (10(-5) M), methysergide (10(-5) M), or diphenhydramine (10(-5) M). Endothelial denudation did not affect hypoxic augmentation. Hypoxia did not cause any alteration of the contractile response to 10(-6) M PGF2 alpha in Ca++-free media. Pretreatment with a calcium channel blocker, nicardipine, significantly inhibited the hypoxic potentiation of the contractile response to 25 mM KCl, 3 X 10(-7) M PGF2 alpha, and 10(-6) M hemoglobin. These results suggest that hypoxia augments the contractile response to these agonists by a direct action on the smooth-muscle cells, facilitating the transmembrane influx of extracellular calcium. Hypoxia of smooth-muscle cells in the major cerebral arteries might be involved in the pathogenesis of vasospasm.

Cerebral vasospasm

Cerebral vasospasm is an important component of pathological entities such as migraine, subarachnoid hemorrhage (SAH), head trauma, post cerebral ischemia and/or hypoxia. The mechanisms underlying cerebral vasospasm in these diseases are not completely understood. Neurochemical and morphological factors involved in the cerebral circulation control are reviewed in this article. The circulatory changes observed after subarachnoid hemorrhage are taken as a model. It is concluded that multiple biochemical, physiological and morphological factors are involved in the cerebral vascular responses after SAH. Possible treatment alternatives for cerebral vasospasm based on its etiology are discussed.

Survey of clinical experience with nimodipine in patients with subarachnoid hemorrhage

The present studies show that nimodipine prevents and/or improves permanent ischemic neurological deficits in patients with subarachnoid hemorrhage. This was particularly marked in four double-blind, placebo-controlled studies in which statistically significant reductions in mortality and morbidity as consequence of cerebral vasospasm were found. The drug has been shown to increase cerebral blood flow, to reduce vasoconstriction, although not to fully prevent angiographic vasospasm, and to improve central conduction time. Nimodipine did not increase the rate of rebleeding. Its administration during anesthesia does not result in management problems. In general, nimodipine was well tolerated. Side effects were recorded mainly in open studies using the intravenous formulation and consisted mainly of decreases in blood pressure and headaches. Transient increases in liver enzymes may be due to the organic solvent. Hence, all results indicate that patients with subarachnoid hemorrhage will benefit from preventive or therapeutic nimodipine treatment.

Oral nimodipine reduces prostaglandin and thromboxane production by arteries chronically exposed to a periarterial haematoma and the antifibrinolytic agent tranexamic acid

The calcium antagonist nimodipine blocks the effects of many vasoconstrictors of cerebrovascular smooth muscle and may reduce the incidence of delayed cerebral ischaemia following subarachnoid haemorrhage though not necessarily by inhibiting the development of angiographic cerebral vasospasm. Post-haemorrhagic CSF contains abnormally large quantities of various eicosanoids that partly reflect enhanced production by cerebral arteries. Does nimodipine affect this process? The extra-arterial and intra-arterial production of PG6 keto-F1 alpha, PGE2, PGF2 alpha and TXB2 were measured in perfused common carotid arteries taken from rabbits in which the arteries had been ensheathed by blood clot in vivo for 7 days. All rabbits were given the antifibrinolytic agent tranexamic acid to retard resolution of the clot, and half were given oral nimodipine (2 mg/kg/day) for 10 days. Nimodipine significantly reduced the extra-arterial production of TXB2 during the third and fourth hours of perfusion and, less consistently, the production of PGF2 alpha, PGE2 and PG6 keto-F1 alpha. Lutrol, the solvent for nimodipine, had no such effect.

Cerebrovascular and metabolic changes during the delayed vasospasm following experimental subarachnoid hemorrhage in baboons, and treatment with a calcium antagonist

A model has been designed in baboons for simulating the clinical situation during the late phase of vasospasm in patients with subarachnoid hemorrhage (SAH). A total amount of 14-33 ml autologous blood was injected into the cisternal system on 3 occasions in the course of 4 days. Neurological symptoms were seen, and the mortality rate was 29%. Angiography 3 days after the last injection showed arterial vasoconstriction amounting to 23% in the vertebro-basilar system, and 11% (right) and 18% (left) in the carotid system. Cerebral blood flow (CBF) measured by the intra-arterial 133Xe technique and the cerebral metabolic rate of oxygen (CMRO2) were reduced by 18% and 11%, respectively. The hypercapnic CBF response was significantly impaired, from a mean of 3.90 ml/100 g/min to 1.72 ml/100 g/min of flow increase for each mm Hg elevation of paCO2. Autoregulation, tested by administration of angiotensin II, was also significantly affected as evidenced by a pressure-dependent increment of CBF during hypertension in 5 out of 7 animals tested. The impaired autoregulation was reflected in the autoregulatory index, which in the whole group increased from 0.06 ml/100 g/min for each mm Hg increase in MABP in the pre-SAH animals to 0.29 ml/100 g/min per mm Hg post-SAH. Treatment with the calcium antagonist, nimodipine (0.5 microgram/kg/min i.v. during 45 min), enhanced CBF significantly by 17% before experimental SAH, whereas after SAH the effect was slight and did not reach statistical significance; CMRO2 was not significantly affected in either group. Intravenous nimodipine combined with hypertension resulted in a marked increase in the autoregulatory index to 1.58 ml/100 g/min per mm Hg in pre-SAH animals and a less pronounced increment to 0.58 ml/100 g/min per mm Hg following experimental SAH. The beneficial effect of nimodipine reported in SAH patients is therefore, in view of our findings, more likely due primarily to a protective mechanism at the cellular level than to an influence on the vascular bed.

Subarachnoid hemorrhage: a review

Subarachnoid hemorrhage from the rupture of a saccular aneurysm remains a major neurosurgical problem that affects 25,000 to 28,000 people yearly. Unfortunately, the mortality from this devastating disease process has not changed significantly in the last 30 years. For emergency physicians, the early detection and diagnosis of subarachnoid hemorrhage is critical to the potential of reducing the mortality from such an event. This article reviews and updates the natural history of subarachnoid hemorrhage, its incidence, presentation, diagnosis, and management from the standpoint of the emergency physician. It does not explore all controversial areas in exhaustive depth, but rather summarizes material that is of importance to emergency physicians in their approach to the problem.

Nimodipine-induced changes in the distribution of carotid blood flow and cardiac output in pentobarbitone-anaesthetized pigs

In view of the claimed effectiveness of nimodipine in migraine and its possible selectivity for cerebral vessels, we investigated the effects of nimodipine in anaesthetized pigs on the fractionation of carotid arterial blood flow into non-nutrient (arteriovenous anastomoses; AVAs) and nutrient (capillary) parts, and on regional tissue blood flows and vascular conductances. Intracarotid infusions of nimodipine (0.05-1.25 microgram kg-1 min-1) redistributed carotid blood flow in favour of its nutrient compartment, particularly to the skeletal muscles and tongue. Vascular conductance in the non-nutrient (AVAs) compartment decreased (40%), most likely, as a result of 'steal' following profound (5.5 fold) arteriolar dilatation. Intravenous infusions of nimodipine (0.05-6.25 micrograms kg-1 min-1) caused hypotension, bradycardia, a decrease in conduction in the non-nutrient fraction, and an increase in conduction in the nutrient fraction (mostly in the skeletal muscles, but also in the gastrointestinal tract, cerebral hemispheres, heart and adrenals). Probably due to the hypotensive effect, only skeletal muscle blood flow increased. The nimodipine-induced increase in vascular conductance in the skeletal muscles showed regional variation; the effect was most pronounced in the cheek muscles, followed by the muscles of the chest, abdominal, trunk and gluteal regions. We conclude that: AVA flow seems to represent a 'reserve' perfusion which can be readily diverted to tissues in the case of increased metabolism and/or vasodilatation, though the overall response to nimodipine of carotid blood flow distribution qualitatively resembles that to some antimigraine drugs, the relevance of such acute effects in the prophylactic usefulness of nimodipine in migraine remains to be ascertained, and nimodipine lacks a selective cerebral vasodilator action in the anaesthetized pig.

The effects of HA compound calcium antagonists on delayed cerebral vasospasm in dogs

The authors have examined the effects of the HA compounds HA1004(N-(2-guanidinoethyl)-5-isoquinolinesulfonamide) and HA 1077(1-(5-isoquinolinesulfonyl)homopiperazine), which are intracellular calcium antagonists, on delayed cerebral vasospasm from subarachnoid hemorrhage (SAH). The modes of action of these compounds were compared with those of the more commonly used calcium entry blockers. Calcium ionophore A23187 (4.8 X 10(-6) M)-induced contraction of a canine basilar artery strip was completely antagonized by the HA compounds (10(-5) M) but not by the entry-blocking calcium antagonists nicardipine, diltiazem, and verapamil (10(-5) M), suggesting that the HA compounds act differently. Delayed cerebral vasospasm was induced by a "two-hemorrhage" canine model. The magnitude of the vasospasm and the effects of the HA compounds were determined angiographically. On SAH Day 7, a significant vasospasm was observed in every dog. The diameter of the basilar artery had diminished to 59% +/- 2% (mean +/- standard error) of the control value obtained before SAH (on Day 1). The intravenous administration of HA 1004 caused a mild dilation of the basilar artery of 10% and 11% at doses of 3 and 10 mg/kg, respectively; however, HA 1077 produced a more marked dilation of 19% and 27%, respectively, at the same doses. Both of these drugs lowered mean arterial blood pressure to about 80% and 50% at doses of 3 and 10 mg/kg, respectively. Intracisternal administration of the HA compounds (6 mg) completely reversed cerebral vasospasm without much effect on the blood pressure. The intracellular calcium antagonists of the HA compound group appear to be promising agents for the treatment of intractable cerebral vasospasm.

Changes in cerebral blood flow and metabolism following intraarterial or local administration of nimodipine, before and after experimental subarachnoid hemorrhage in baboons

Experimental subarachnoid hemorrhage (SAH) was induced in baboons by repeated injections of autologous blood into cisterna chiasmatis and cisterna magna, a total of 14-33 ml being injected over 3-4 days. Cerebral blood flow (CBF; 133xenon clearance) and cerebral metabolic rate of oxygen (CMRO2) were measured before, and 7 days after, the first blood injection. The effect of the calcium channel blocker, nimodipine, used in a commercially available form for clinical application, was studied following continuous i.a. infusion (0.1 microgram X kg-1 X min-1) for an interval of 45 min, and also 20 and 60 min after intrathecal administration of 1 microgram X kg-1. During the infusion experiments, CBF was increased by 25-30% both before and after the cisternal blood injection. CMRO2 was also enhanced, but much less. Nimodipine in doses given did not alter systemic blood pressure. Following intrathecal application, CBF and CMRO2 slightly increased at 20 min only before experimental SAH.