A randomized controlled trial of high-dose intravenous nicardipine in aneurysmal subarachnoid hemorrhage. A report of the Cooperative Aneurysm Study

Intra-arterial nicardipine infusion improves CT perfusion-measured cerebral blood flow in patients with subarachnoid hemorrhage-induced vasospasm

BACKGROUND AND PURPOSE

Our aim was to determine the effects of intra-arterial (IA) nicardipine infusion on the cerebral hemodynamics of patients with aneurysmal subarachnoid hemorrhage (aSAH)-induced vasospasm by using first-pass quantitative cine CT perfusion (CTP).

MATERIALS AND METHODS

Six patients post-aSAH with clinical and transcranial Doppler findings suggestive of vasospasm were evaluated by CT angiography and CTP immediately before angiography for possible vasospasm treatment. CTP was repeated immediately following IA nicardipine infusion. Maps of mean transit time (MTT), cerebral blood volume (CBV), and cerebral blood flow (CBF) were constructed and analyzed in a blinded manner. Corresponding regions of interest on these maps from the bilateral middle cerebral artery territories and, when appropriate, the bilateral anterior or posterior cerebral artery territories, were selected from the pre- and posttreatment scans. Normalized values were compared by repeated measures analysis of variance.

RESULTS

Angiographic vasospasm was confirmed in all patients. In 5 of the 6 patients, both CBF and MTT improved significantly in affected regions in response to nicardipine therapy (mean increase in CBF, 41 +/- 43%; range, -9%-162%, P = .0004; mean decrease in MTT, 26 +/- 24%; range, 0%-70%, P = .0002). In 1 patient, we were unable to quantify improvement in flow parameters due to section-selection differences between the pre- and posttreatment examinations.

CONCLUSIONS

IA nicardipine improves CBF and MTT in ischemic regions in patients with aSAH-induced vasospasm. Our data provide a tissue-level complement to the favorable effects of IA nicardipine reported on prior angiographic studies. CTP may provide a surrogate marker for monitoring the success of treatment strategies in patients with aSAH-induced vasospasm.

[Ischemic complications in neurosurgery: use of calcium antagonists]

Dysregulation of the intracellular calcium concentration is thought to play a key role in the so-called ischemic cascade, as well as for the development of cerebral vasospasm after subarachnoid haemorrhaging (SAH). Therefore, the prophylactic/therapeutic administration of cerebral calcium channel blockers for neurosurgical patients appears to be a compelling idea to prevent ischemic complications. There are abundant data on the efficacy of cerebral calcium antagonists in various animal models of central nervous system pathologies, however, very little clinical evidence exists to justify their use in humans in respective situations. So far there is only evidence for a long-term treatment effect of oral nimodipine in patients suffering from SAH, and this is based essentially on one large controlled clinical trial. Experimental results suggest that blockers of other calcium channel subtypes may be promising for future clinical roles in primary or secondary ischemic brain injury. However, it is also possible that calcium-independent mechanisms play a more important role during the development of the ischemic damage than previously assumed. Currently, there is no clinical evidence to support the prophylactic use of calcium antagonists to prevent ischemic complications in neurosurgical patients without SAH.

CONTROVERSIES IN THE ENDOVASCULAR MANAGEMENT OF CEREBRAL VASOSPASM AFTER INTRACRANIAL ANEURYSM RUPTURE AND FUTURE DIRECTIONS FOR THERAPEUTIC APPROACHES

CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage. Despite maximal medical therapy, however, up to 15% of patients surviving the ictus of subarachnoid hemorrhage experience stroke or death from vasospasm. For those cases of vasospasm that are refractory to medical treatment, endovascular techniques are frequently used, including balloon angioplasty with or without intra-arterial infusion of vasodilators, combined endovascular modalities, and aortic balloon devices. In this article, we review each of these therapies and their expanding role in the management of this condition. Moving forward, rigorous prospective outcome assessments after endovascular treatment of cerebral vasospasm are necessary to clearly delineate the efficacy and indications for these techniques.

New insights into the causes and therapy of cerebral vasospasm following subarachnoid hemorrhage

Cerebral vasospasm lingers as the leading preventable cause of death and disability in patients who experience aneurysmal subarachnoid hemorrhage. Despite the potentially devastating consequences of cerebral vasospasm, the mechanisms behind it are incompletely understood. Nitric oxide, endothelin-1, bilirubin oxidation products and inflammation appear to figure prominently in its pathogenesis. Therapies directed at many of these mechanisms are currently under investigation and hold significant promise for an ultimate solution to this substantial problem.

ADMISSION ANGIOGRAPHIC CEREBRAL CIRCULATION TIME MAY PREDICT SUBSEQUENT ANGIOGRAPHIC VASOSPASM AFTER ANEURYSMAL SUBARACHNOID HEMORRHAGE

OBJECTIVE

Angiographic cerebral vasospasm occurs in approximately 70% of patients hospitalized after aneurysmal subarachnoid hemorrhage (SAH) and is associated with poor outcome. In this study, we examined whether or not cerebral circulation time (CCT) measured with digital subtraction angiography was associated with angiographic vasospasm.

METHODS

Patients who underwent cerebral angiography within 24 hours of SAH were analyzed. Contrast dye transit time from the arterial to the venous phase was measured to obtain CCT (supraclinoid internal carotid artery to parietal cortical veins) and microvascular CCT (cortical middle cerebral artery to parietal cortical veins). Patients with ruptured anterior circulation aneurysms and vasospasm on follow-up angiography (Group A) were compared with patients with SAH without vasospasm (Group B) and with normal control subjects (Group C).

RESULTS

There were 20 patients in Group A (mean age, 51 ± 13 yr), 17 patients in Group B (56 ± 12 yr), and 98 patients in Group C (52 ± 12 yr). CCT in patients in Group A (7.7 ± 1.9 s) was significantly longer than those in Groups B (6.6 ± 1.2 s; P = 0.005) and C (5.9 ± 1 s; P < 0.001). Microvascular CCT in patients in Group A (7.1 ± 1.8 s) was significantly longer than those in Groups B (6.1 ± 1.2 s; P = 0.003) and C (5.4 ± 0.9 s; P < 0.001).

CONCLUSION

Prolonged CCT, a measurement of increased small vessel resistance, can be identified within 24 hours after SAH and is associated with subsequent angiographic vasospasm. These results suggest that microcirculation changes may be involved in vasospasm.

Early ischemic lesion on computed tomography: predictor of poor outcome among survivors of aneurysmal subarachnoid hemorrhage

Object

Identifying ischemic lesions after subarachnoid hemorrhage (SAH) is important because the appearance of these lesions on follow-up imaging correlates with a poor outcome. The effect of ischemic lesions seen on computed tomography (CT) scans during the first days of treatment remains unknown, however.

Methods

In 156 patients with SAH, clinical course and outcome, as well as the appearance of ischemic lesions on serial CT scans, were prospectively monitored for 3 months. At 3 months after SAH, magnetic resonance imaging was performed to detect permanent lesions that had not been visible on CT.

Results

Of the 53 patients with no lesions on any of the follow-up CT scans, four (8%) had a poor outcome. Of the 52 patients with a new hypodense lesion on the first postoperative day CT, 23 (44%) had a poor outcome. Among the remaining 51 patients with a lesion appearing later than the first postoperative morning, 10 (20%) had a poor outcome (p < 0.001). After adjusting for patient age; clinical condition on admission; amounts of subarachnoid, intracerebral, and intraventricular blood; and plasma glucose and D-dimer levels, a hypodense lesion on CT on the first postoperative morning was an independent predictor of poor outcome after SAH (odds ratio 7.27, 95% confidence interval 1.54–34.37, p < 0.05).

Conclusions

A new hypodense lesion on early postoperative CT seems to be an independent risk factor for poor outcome after SAH, and this early lesion development may be more detrimental to clinical outcome than a later lesion occurrence.

Erythropoietin in patients with aneurysmal subarachnoid haemorrhage: a double blind randomised clinical trial

BACKGROUND

Erythropoietin (EPO) is neuroprotective in experimental models of stroke and subarachnoid haemorrhage (SAH) and possibly in patients with thromboembolic stroke. We studied the efficacy and safety of EPO in patients with SAH.

METHODS

A larger scale clinical trial was planned but preliminarily terminated because of a lower than expected inclusion rate. However, 73 patients were randomised to treatment with EPO (500 IU/kg/day for three days) or placebo. The primary endpoint was Glasgow Outcome Score at six months. We further studied surrogate measures of secondary ischaemia, i.e. transcranial Doppler (TCD) flow velocity, symptomatic vasospasm, cerebral metabolism (microdialysis) and jugular venous oximetry, biochemical markers of brain damage (S-100beta and neuron specific enolase) and blood-brain barrier integrity.

FINDINGS

The limited sample size precluded our primary hypotheses being verified and refuted. However, data from this study are important for any other study of SAH and as much raw data as possible are presented and can be included in future meta analyses. On admission the proportion of patients in a poor condition was higher in the EPO group compared with the placebo group but the difference was statistically insignificant. In the EPO-treated patients the CSF concentration of EPO increased 600-fold. Except for a higher extracelullar concentration of glycerol in the EPO group probably caused by the poorer clinical condition of these patients, there were no statistically significant group differences in the primary or secondary outcome measures. EPO was well tolerated.

CONCLUSIONS

Beneficial effects of EPO in patients with SAH cannot be excluded or concluded on the basis of this study and larger scale trials are warranted.

Advances in vasospasm treatment and prevention

Outcome after aSAH depends on several factors, including the severity of the initial event, perioperative medical management, surgical variables, and the incidence of complications. Cerebral vasospasm (CV) is ure to consistently respond to treatment, emphasizing the need for further research into the underlying mechanisms of SAH-induced cerebrovascular dysfunction. To this end, our paper reviews the relevant literature on the main therapies employed for CV after aSAH and discusses possible avenues for future investigations. Current management of this condition consists of maximal medical therapy, including triple H regimen and oral administration of calcium antagonists, followed by endovascular balloon angioplasty and/or injection of vasodilatory agents for refractory cases. As the precise pathophysiology of CV is further elucidated, the development of promising investigational therapies will follow.

A Randomized Controlled Trial of Hydrocortisone Against Hyponatremia in Patients With Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Hyponatremia is common after aneurysmal subarachnoid hemorrhage (SAH). It is caused by natriuresis, which induces osmotic diuresis and decreases blood volume, contributing to symptomatic cerebral vasospasm (SCV). Hypervolemic therapy to prevent SCV will not be efficient under this condition. We conducted a randomized controlled trial to assess the efficacy of hydrocortisone, which promotes sodium retention in the kidneys.

METHODS

Seventy-one SAH patients were randomly assigned after surgery to treatment with either a placebo (n=36) or 1200 mg/d of hydrocortisone (n=35) for 10 days and tapered thereafter. Both groups underwent hypervolemic therapy. The primary end point was the prevention of hyponatremia.

RESULTS

Hydrocortisone prevented excess sodium excretion (P=0.04) and urine volume (P=0.04). Hydrocortisone maintained the targeted serum sodium level throughout the 14 days (P<0.001), and achieved the management protocol with lower sodium and fluid (P=0.007) supplementation. Hydrocortisone kept the normal plasma osmolarity (P<0.001). SCV occurred in 9 patients (25%) in the placebo group and in 5 (14%) in the hydrocortisone group. No significant difference in the overall outcome was observed between the 2 groups.

CONCLUSIONS

Hydrocortisone overcame excess natriuresis and prevented hyponatremia. Although there was no difference in outcome, hydrocortisone supported efficient hypervolemic therapy.

Outcome in patients with subarachnoid hemorrhage treated with antiepileptic drugs

Object

Prophylactic use of antiepileptic drugs (AEDs) in patients admitted with aneurysmal subarachnoid hemorrhage (SAH) is common practice; however, the impact of this treatment strategy on in-hospital complications and outcome has not been systematically studied. The goal in this study was twofold: first, to describe the prescribing pattern for AEDs in an international study population; and second, to delineate the impact of AEDs on in-hospital complications and outcome in patients with SAH.

Methods

The authors examined data collected in 3552 patients with SAH who were entered into four prospective, randomized, double-blind, placebo-controlled trials conducted in 162 neurosurgical centers and 21 countries between 1991 and 1997. The prevalence of AED use was assessed by study country and center. The impact of AEDs on in-hospital complications and outcome was evaluated using conditional logistic regressions comparing treated and untreated patients within the same study center.

Results

Antiepileptic drugs were used in 65.1% of patients and the prescribing pattern was mainly dependent on the treating physicians: the prevalence of AED use varied dramatically across study country and center (intraclass correlation coefficients 0.22 and 0.66, respectively [p < 0.001]). Other predictors included younger age, worse neurological grade, and lower systolic blood pressure on admission. After adjustment, patients treated with AEDs had odds ratios of 1.56 (95% confidence interval [CI] 1.16–2.10; p = 0.003) for worse outcome based on the Glasgow Outcome Scale; 1.87 (95% CI 1.43–2.44; p < 0.001) for cerebral vasospasm; 1.61 (95% CI 1.25–2.06; p < 0.001) for neurological deterioration; 1.33 (95% CI 1.01–1.74; p = 0.04) for cerebral infarction; and 1.36 (95% CI 1.03–1.80; p = 0.03) for elevated temperature during hospitalization.

Conclusions

Prophylactic AED treatment in patients with aneurysmal SAH is common, follows an arbitrary prescribing pattern, and is associated with increased in-hospital complications and worse outcome.

Calcium antagonists for aneurysmal subarachnoid haemorrhage

BACKGROUND

Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has been incompletely elucidated, but vasospasm probably is a contributing factor. Experimental studies have suggested that calcium antagonists can prevent or reverse vasospasm and have neuroprotective properties.

OBJECTIVES

To determine whether calcium antagonists improve outcome in patients with aneurysmal SAH.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched April 2006), MEDLINE (1966 to March 2006) and EMBASE (1980 to March 2006). We handsearched two Russian journals (1990 to 2003), and contacted trialists and pharmaceutical companies in 1995 and 1996.

SELECTION CRITERIA

Randomised controlled trials comparing calcium antagonists with control, or a second calcium antagonist (magnesium sulphate) versus control in addition to another calcium antagonist (nimodipine) in both the intervention and control groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality. Trialists were contacted to obtain missing information.

MAIN RESULTS

Sixteen trials, involving 3361 patients, were included in the review; three of the studies were of magnesium sulphate in addition to nimodipine. Overall, calcium antagonists reduced the risk of poor outcome: the relative risk (RR) was 0.81 (95% confidence interval (CI) 0.72 to 0.92); the corresponding number of patients needed to treat was 19 (95% CI 1 to 51). For oral nimodipine alone the RR was 0.67 (95% CI 0.55 to 0.81), for other calcium antagonists or intravenous administration of nimodipine the results were not statistically significant. Calcium antagonists reduced the occurrence of secondary ischaemia and showed a favourable trend for case fatality. For magnesium in addition to standard treatment with nimodipine, the RR was 0.75 (95% CI 0.57 to 1.00) for a poor outcome and 0.66 (95% CI 0.45 to 0.96) for clinical signs of secondary ischaemia.

AUTHORS' CONCLUSIONS

Calcium antagonists reduce the risk of poor outcome and secondary ischaemia after aneurysmal SAH. The results for 'poor outcome' depend largely on a single large trial of oral nimodipine; the evidence for other calcium antagonists is inconclusive. The evidence for nimodipine is not beyond all doubt, but given the potential benefits and modest risks of this treatment, oral nimodipine is currently indicated in patients with aneurysmal SAH. Intravenous administration of calcium antagonists cannot be recommended for routine practice on the basis of the present evidence. Magnesium sulphate is a promising agent but more evidence is needed before definite conclusions can be drawn.

Predictors of cerebral infarction in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

Cerebral infarction would be expected to be associated with poor outcome after aneurysmal subarachnoid hemorrhage (SAH), although there are few data on which to base this assumption. The goals of this study were to determine the impact of cerebral infarction on outcome and to examine predictors of infarction in these patients.

METHODS

Univariate and multivariable statistical methods were used to examine the impact of cerebral infarction on the Glasgow Outcome Scale score 3 months after SAH among 3567 patients entered into four prospective, randomized, double-blind, placebo-controlled trials of tirilazad conducted in neurosurgical centers around the world between 1991 and 1997. Patient demographics, clinical variables, radiographic characteristics, and treatment variables associated with cerebral infarction were also determined by the same methods.

RESULTS

Seven hundred and seven (26%) out of 2741 patients with complete data had cerebral infarction on computed tomographic scans 6 weeks after SAH. Multivariable logistic regression showed that cerebral infarction increased the odds of unfavorable outcome by a factor of 5.4 (adjusted odds ratio, 5.4; 95% confidence interval, 4.2-6.8; P < 0.0001), which was a higher odds ratio than all other factors associated with outcome. The proportion of explained variance in outcome was also highest for cerebral infarction and accounted for 39% of the explained variance. Multivariable analysis found that cerebral infarction was significantly associated with increasing patient age, worse neurological grade on admission, history of hypertension or diabetes mellitus, larger aneurysm, use of prophylactically or therapeutically induced hypertension, temperature more than 38 degrees C 8 days after SAH, and symptomatic vasospasm.

CONCLUSION

Cerebral infarction was strongly associated with poor outcome after aneurysmal SAH. The most important potentially treatable factor associated with infarction was symptomatic vasospasm.

Preliminary experience with intra-arterial nicardipine in patients with acute ischemic stroke

OBJECTIVE

To report experience with intra-arterial (IA) calcium channel blocker (nicardipine) in patients with acute ischemic stroke with and without reteplase, mechanical thrombectomy (snare), and primary angioplasty to achieve maximal recanalization. Selective delivery of calcium channel blocker may improve perfusion and possibly provide neuroprotection in cerebral ischemia.

METHODS

We performed a retrospective study to determine the angiographic and clinical outcomes among patients treated with IA nicardipine administered as 2.5-5 mg dose either alone or adjunct to intra-arterial thrombolysis. Mean arterial pressure and heart rate were recorded throughout the injection. Angiographic severity of initial occlusion and recanalization was assessed using the Qureshi grading scheme. Neurological examinations and computed tomographic scans were performed prior to, immediately, and 24 h after thrombolysis for each patient, to assess the neurological improvement and symptomatic or asymptomatic intracranial hemorrhages.

RESULTS

Ten patients median age of 60 years (age range: 35-93 years) were administered IA nicardipine. The median admission National Institutes of Health Stroke Scale (NIHSS) score was 14 (range 6-19). All patients received IA nicardipine either in combination with thrombolytics (n = 6) or as monotherapy (n = 4). The average decrease in mean arterial pressure (MAP) was 10 mmHg; except one patient who had an asymptomatic decline of 34 mm Hg, which responded to fluid resuscitation. None of the patients suffered any procedural and post-procedural complication. Overall recanalization (improvement in one grade or greater) was observed in 2 of 10 patients with IA nicardipine with or without thrombolytic treatment. Other angiographic changes observed included improvement in collateral flow (n = 2), increase in transit time (n = 1), and vasodilation of distal arteries and branches (n = 4). No patient demonstrated any worsening from the baseline grade in response to IA nicardipine. Of the two patients who underwent serial magnetic resonance imaging (MRI) and one patient demonstrated reversal of pretreatment restricted diffusion. Neurological improvement defined by a decrease of four points or greater was observed in four patients at 24 h following treatment.

CONCLUSION

Intra-arterial delivery of nicardipine in doses up to 5 mg is well tolerated among patients with acute ischemic stroke. Further studies are required to determine the potential efficacy of this approach with or without thrombolytics.

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.

The challenge of blood pressure management in neurologic emergencies

Hypertensive crises are commonly seen in the emergency department, and acute stroke is often the inciting etiology of a hypertensive crisis. Cerebral autoregulation is disrupted in acute stroke, and efforts to lower blood pressure may reduce cerebral perfusion and worsen outcomes. Although most patients with stroke have elevated blood pressure, evidence from clinical trials to guide therapy are scarce. Current national guidelines recommend lowering blood pressure after stroke only if end-organ damage is present or if systolic/diastolic blood pressures exceed 220/120 or 185/110 mm Hg in patients ineligible and in those eligible to receive thrombolytic drug therapy, respectively. Recommended pharmacologic interventions for elevated blood pressure after acute ischemic stroke include labetalol, nicardipine, or nitroprusside, depending on the severity of the elevation. Similar recommendations have been made for intracerebral hemorrhage. Subarachnoid hemorrhage is managed with nimodipine and other calcium channel blockers to prevent vasospasm and improve clinical outcomes. Data from ongoing clinical trials may improve guidance about the management of elevated blood pressure after acute stroke.

Management of arterial hypertension in patients with acute stroke

Management of arterial hypertension in the hyperacute period immediately after stroke ictus remains controversial. Extremes of blood pressure (BP) are associated with poor outcomes in all stroke subtypes. Severely hypertensive patients likely benefit from modest BP reductions, but aggressive BP reduction may worsen outcome. Although little evidence is currently available to definitively establish guideline recommendations for optimal BP goals at stroke presentation, recently published research is shedding some light on how to approach management of BP after stroke. Antihypertensive treatment should probably be deferred in ischemic stroke patients except in cases of severe hypertension or when thrombolytic therapy is warranted and the patient's BP is above acceptable levels. Hypertensive hemorrhagic stroke patients may benefit from modest BP reductions. Relative hypotension causing regional hypoperfusion is an increasingly understood concept immediately following ischemic or hemorrhagic stroke, emphasizing the need for careful titration of appropriate medications to minimize fluctuations in BP for treated patients. Ongoing trials will improve our current knowledge regarding BP management after ischemic and hemorrhagic stroke.

Effects of intraoperative hypothermia on neuropsychological outcomes after intracranial aneurysm surgery

OBJECTIVE

Subarachnoid hemorrhage and surgical obliteration of ruptured intracranial aneurysms are frequently associated with neurological and neuropsychological abnormalities. We reported that intraoperative cooling did not improve neurological outcome in good-grade surgical subarachnoid hemorrhage patients, as assessed by the Glasgow Outcome Scale score or other neurological and functional measures (National Institutes of Health Stroke Scale, Rankin Disability Scale, Barthel Activities of Daily Living). We now report the results of neuropsychological testing in these patients.

METHODS

A total of 1,001 patients who bled < or = 14 days before surgery were randomly assigned to intraoperative hypothermia (t = 33 degrees C) or normothermia (37 degrees C). Outcome was assessed approximately 3 months after surgery. Patients underwent the Benton Visual Retention, Controlled Oral Word Association, Rey-Osterrieth Complex Figure, Grooved Pegboard, and the Trail Making tests. T-scores for each test were calculated from normative data. T-scores were averaged to calculate a Composite Score. A test result (or the Composite Score) was considered "impaired" if the T-score was two or more standard deviations below the norm. A Mini-Mental State Examination was also performed.

RESULTS

Neurological outcome data were available in 1,000 patients. Sixty-one patients died. Of the 939 survivors, 873 completed 3 or more tests (exclusive of the Mini-Mental State Examination). Patients with poor neurological outcomes were less likely to complete testing; only 3.9% of Good Outcome (Glasgow Outcome Scale score = 1) patients were untested, compared with 38.6% of patients with Glasgow Outcome Scale scores of 3 and 4. There were no prerandomization demographic differences between the two treatment groups. For hypothermic patients, 16.8% were impaired from their Composite Score versus 20.0% of patients in the normothermic group (p = 0.317). For patients in the hypothermic group, 54.5% were impaired on at least one test, compared with 55.5% of patients in the normothermic group (p = 0.865). Similar results were seen in patients with baseline WFNS scores = I. Mini-Mental State Examination scores in the hypothermic and normothermic groups were 27.4 +/- 3.8 and 26.8 +/- 4.5, respectively.

INTERPRETATION

This is the largest prospective evaluation of neuropsychological function after subarachnoid hemorrhage to date. Testing was completed in a high fraction of patients, demonstrating the feasibility of such testing in a large trial. However, the frequent inability to complete testing in poor-outcome patients suggests that testing may be best used to refine outcome assessments in good-grade patients. Many patients showed impairment on at least one test, with global impairment present in 17 to 20% of patients (18-21% of survivors). This was true even among the patients with the best preoperative condition (WFNS = 1). There was no difference in the incidence of impairment between hypothermic and normothermic groups.

Update on endovascular therapies for cerebral vasospasm induced by aneurysmal subarachnoid hemorrhage

Cerebral vasospasm remains a major source of morbidity and death in patients with aneurysmal subarachnoid hemorrhage (SAH). When vasospasm becomes refractory to maximal medical management consisting of induced hypertension and hypervolemia and administration of calcium channel antagonists, endovascular therapies should be considered. The primary goal of endovascular treatment is to increase cerebral blood flow to prevent cerebral infarction. Two of the more frequently studied endovascular treatments are transluminal balloon angioplasty and intraarterial papaverine infusion. These two have been used either alone or in combination for the treatment of vasospasm. Other pharmacological vasodilating agents currently being investigated are intraarterial nimodipine, nicardipine, verapamil, and milrinone. Newer intraarterial agents, such as fasudil and colforsin daropate, have also been investigated. In this article the authors review the current options in terms of endovascular therapies for treatment of cerebral vasospasm. The mechanism of action, technique of administration, clinical effect and outcomes, and complications of each modality are discussed.

Evidence-based cerebral vasospasm management

Cerebral vasospasm and delayed cerebral ischemia remain common complications of aneurysmal subarachnoid hemorrhage (SAH), and yet therapies for cerebral vasospasm are limited. Despite a large number of clinical trials, only calcium antagonists have strong evidence supporting their effectiveness. The purpose of this work was to perform a systematic review of the literature on the treatment of cerebral vasospasm. A literature search for randomized controlled trials of therapies used for prevention or treatment of cerebral vasospasm and/or delayed cerebral ischemia was conducted, and 41 articles meeting the review criteria were found. Study characteristics and primary results of these articles are reviewed. Key indicators of quality were poor when averaged across all studies, but have improved greatly over time. The only proven therapy for vasospasm is nimodipine. Tirilazad is not effective, and studies of hemodynamic maneuvers, magnesium, statin medications, endothelin antagonists, steroid drugs, anticoagulant/antiplatelet agents, and intrathecal fibrinolytic drugs have yielded inconclusive results. The following conclusions were made: nimodipine is indicated after SAH and tirilazad is not effective. More study of hemodynamic maneuvers, the effectiveness of other calcium channel antagonists such as nicardipine delivered by other routes (for example intrathecally), magnesium, statin drugs, endothelin antagonists, and intrathecal fibrinolytic therapy is warranted. There is less enthusiasm for the study of steroid drugs and anticoagulant/antiplatelet agents because they entail more risks and investigations so far have shown little evidence of efficacy. The study of rescue therapy such as balloon angioplasty and intraarterial vasodilating agents will be difficult. The quality of clinical trials should be improved.

Dissociation between vasospasm and functional improvement in a murine model of subarachnoid hemorrhage

OBJECT

The efficacy of nimodipine was examined in a murine model of subarachnoid hemorrhage (SAH). End points included the diameter of the lumen of the middle cerebral artery (MCA) and behavioral outcome. An apolipoprotein E (apoE)-mimetic peptide, acetyl-AS-Aib-LRKL-Aib-KRLL-amide, previously shown to have promise in this model was tested both alone and in combination with nimodipine. The effects of carboxyamidotriazole (CAI), a non-voltage-gated calcium channel blocker, were explored using the same animal paradigm.

METHODS

Experimental SAH was induced in male C57B1/6J mice. For 3 days postoperatively, behavioral analyses were performed. In the first experiment, the mice were treated with vehicle or with low- or high-dose CAI for 3 days. In the second experiment, the mice were treated with vehicle, high- and low-dose nimodipine, and/or the apoE-mimetic peptide. On postoperative Day 3 each mouse was killed and perfused. Following this, the right MCA was removed and its lumen measured. Mice that received nimodipine demonstrated significant behavioral improvements when compared with vehicle-treated mice, but there was no clear dose-dependent effect on MCA diameter. Administration of the apoE-mimetic peptide was associated with improved functional performance and a significant reduction in vasospasm. Mice that received high-dose CAI performed worse on functional tests, despite a significant increase in the diameters of their MCA lumina.

CONCLUSIONS

These results demonstrate a dissociation between vasospasm and neurological outcomes that is consistent with findings of previous clinical trials.

Can angiographic vasospasm be used as a surrogate marker in evaluating therapeutic interventions for cerebral vasospasm?

✓ The authors tested the null hypothesis that published literature with a high level of evidence does not support the assertion that subarachnoid hemorrhage (SAH) causes cerebral vasospasm, which in turn causes cerebral infarction and poor outcome after aneurysmal SAH. The medical literature on SAH was searched in MEDLINE. The author's personal files of all published literature on SAH were reviewed. References cited in Cochrane reviews as well as the published papers that were reviewed were also retrieved.

There is no question that SAH causes what the authors have chosen to call “angiographic vasospasm.” However, the incidence and severity of vasospasm in recent series of patients is not well defined. There is reasonable evidence that vasospasm causes infarction, but again, accurate data on how severe and how diffuse vasospasm has to be to cause infarction and how often vasospasm is the primary cause of infarction are not available. There are good data on the incidence of cerebral infarction after SAH, and these data indicate that it is highly associated with poor outcome. The link between angiographic vasospasm and poor outcome is particularly poorly described in terms of what would be considered data of a high level of evidence.

The question as to whether there is a clear pathway from SAH to vasospasm to cerebral infarction to poor outcome seems so obvious to neurosurgeons as to make it one not worth asking. Nevertheless, the obvious is not always true or accurate, so it is important to note that published literature only weakly supports the causative association of vasospasm with infarction and poor outcome after SAH. It behooves neurosurgeons to document this seemingly straightforward pathway with high-quality evidence acceptable to the proponents of evidence-based medicine.

A review of current and future medical therapies for cerebral vasospasm following aneurysmal subarachnoid hemorrhage

✓In an effort to help clarify the current state of medical therapy for cerebral vasospasm, the authors reviewed the relevant literature on the established medical therapies used for cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH), and they discuss burgeoning areas of investigation. Despite advances in the treatment of aneurysmal SAH, cerebral vasospasm remains a common complication and has been correlated with a 1.5- to threefold increase in death during the first 2 weeks after hemorrhage. A number of medical, pharmacological, and surgical therapies are currently in use or being investigated in an attempt to reverse cerebral vasospasm, but only a few have proven to be useful. Although much has been elucidated regarding its pathophysiology, the treatment of cerebral vasospasm remains a dilemma. Although a poor understanding of SAH-induced cerebral vasospasm pathophysiology has, to date, hampered the development of therapeutic interventions, current research efforts promise the eventual production of new medical therapies.

Current Indications for Aneurysm Surgery

Treatment of cerebral aneurysm has changed greatly over the last several years. Although surgery was the treatment of choice for decades, coiling is coming into more prevalent use now. This article highlights when each modality should be used.

PREDICTION OF SYMPTOMATIC VASOSPASMAFTER SUBARACHNOID HEMORRHAGE

OBJECTIVE

We developed a modification of the Fisher computed tomographic rating scale and compared it with the original Fisher scale to determine which scale best predicts symptomatic vasospasm after subarachnoid hemorrhage.

METHODS

We analyzed data from 1355 subarachnoid hemorrhage patients in the placebo arm of four randomized, double-blind, placebo-controlled studies of tirilazad. Modified Fisher computed tomographic grades were calculated on the basis of the presence of cisternal blood and intraventricular hemorrhage. Crude odds ratios (OR) reflecting the risk of developing symptomatic vasospasm were calculated for each scale level, and adjusted ORs expressing the incremental risk were calculated after controlling for known predictors of vasospasm.

RESULTS

Of 1355 patients, 451 (33%) developed symptomatic vasospasm. For the modified Fisher scale, compared with Grade 0 to 1 patients, the crude OR for vasospasm was 1.6 (95% confidence interval [CI], 1.0-2.5) for Grade 2, 1.6 (95% CI, 1.1-2.2) for Grade 3, and 2.2 (95% CI, 1.6-3.1) for Grade 4. For the original Fisher scale, referenced to Grade 1, the OR for vasospasm was 1.3 (95% CI, 0.7-2.2) for Grade 2, 2.2 (95% CI, 1.4-3.5) for Grade 3, and 1.7 (95% CI, 1.0-3.0) for Grade 4. Early angiographic vasospasm, history of hypertension, neurological grade, and elevated admission mean arterial pressure were identified as risk factors for symptomatic vasospasm. After adjusting for these variables, the modified Fisher scale remained a significant predictor of vasospasm (adjusted OR, 1.28; 95% CI, 1.06-1.54), whereas the original Fisher scale was not.

CONCLUSION

The modified Fisher scale, which accounts for thick cisternal and ventricular blood, predicts symptomatic vasospasm after subarachnoid hemorrhage more accurately than original Fisher scale.

Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage: An Overview of Pharmacologic Management

Cerebral vasospasm remains one of the leading causes of mortality in patients who experience a subarachnoid hemorrhage but survive the initial 24 hours. Vasospasm generally occurs 3-4 days after the initial subarachnoid hemorrhage and peaks at 5-7 days. The pathophysiology of vasospasm is poorly understood, which directly contributes to the inconsistency of management and creates a formidable challenge in clinical practice. Traditionally, hemodilution, hypervolemia, and induced hypertension (so-called triple H therapy); calcium channel blockers; and endovascular therapy have been used as either prophylactic therapy or treatment. However, management of vasospasm varies among physicians and institutions mainly because of a lack of large clinical trials and inconsistent results. Practice has been based primarily on case reports and the preference of each practitioner. Several experimental therapies have been explored; however, large, prospective, randomized controlled trials are needed to elucidate the role of these therapies.

Blood pressure management during acute ischaemic stroke

Control of hypertension is a well-established goal of primary stroke prevention. Management of blood pressure in patients during acute ischaemic stroke, however, is complicated by the need to maintain brain perfusion. Lowering blood pressure in the acute setting may avoid the deleterious effects of high blood pressure but may also lead to cerebral hypoperfusion and worsening of the ischaemic stroke. Little information is available from clinical trials concerning optimal blood pressure management in acute stroke. Current protocols of thrombolytic therapy require strict blood pressure control below certain prescribed limits; however, in most acute stroke patients not treated with thrombolysis, blood pressure reduction is not routinely recommended and guidelines for target blood pressures are difficult to justify. Preliminary studies, in fact, suggest that there may be a role for blood pressure elevation in the treatment of some patients with acute ischaemic stroke.

Intravenous Nicardipine

Nicardipine is a water soluble calcium channel antagonist, with predominantly vasodilatory actions. Intravenous (IV) nicardipine (Cardene IV), which demonstrates a relatively rapid onset/offset of action, is used in situations requiring the rapid control of blood pressure (BP). IV nicardipine was as effective as IV nitroprusside in the short-term reduction of BP in patients with severe or postoperative hypertension. A potential role for IV nicardipine in the intraoperative acute control of BP in patients undergoing various surgical procedures (including cardiovascular, neurovascular and abdominal surgery), and in the deliberate induction of reduced BP in surgical procedures in which haemostasis may be difficult (e.g. surgery involving the hip or spine) was demonstrated in preliminary studies. Preliminary studies also indicated the ability of a bolus dose of IV nicardipine to attenuate the hypertensive response, but not the increase in tachycardia, after laryngoscopy and tracheal intubation in anaesthetised patients. In large, well designed studies, IV nicardipine prevented cerebral vasospasm in patients with recent aneurysmal subarachnoid haemorrhage; however, overall clinical outcomes at 3 months were similar to those in patients who received standard management. Small preliminary studies have investigated the use of IV nicardipine in a variety of other settings, including acute intracerebral haemorrhage, acute ischaemic stroke, pre-eclampsia, acute aortic dissection, premature labour and electroconvulsive therapy.In conclusion, the efficacy of IV nicardipine in the short-term treatment of hypertension in settings for which oral therapy is not feasible or not desirable is well established. The ability to titrate IV nicardipine to the tolerance levels of individual patients makes this agent an attractive option, especially in critically ill patients or those undergoing surgery. Potential exists for further investigation of the use of this agent in clinical settings where a vasodilatory agent with minimal inotropic effects is appropriate.

Endovascular treatment of cerebral vasospasm: transluminal balloon angioplasty, intra-arterial papaverine, and intra-arterial nicardipine

Cerebral vasospasm is still one of the leading causes of morbidity and mortality from subarachnoid hemorrhage. Vasospasm refractory to medical management can be treated with endovascular therapies, such as transluminal balloon angioplasty or infusion of intra-arterial vasodilating agents. In our review of clinical series reported in the English language literature, transluminal balloon angioplasty produced clinical improvement in 62% of patients, significantly improved mean transcranial Doppler (TCD) velocities(P <.05), significantly improved cerebral blood flow (CBF) in 85% of patients as studied by (133)Xenon techniques and serial single photon emission computerized tomography,and was associated with 5.0% complications and 1.1% vessel rupture. Intra-arterial papaverine therapy produced clinical improvement in 43% of patients but only transiently,requiring multiple treatment sessions (1.7 treatments per patient); significantly improved mean TCD velocities (P <.01) but only for less than 48 hours; improved CBF in 60% of patients but only for less than 12 hours; and was associated with increases in intracranial pressure and 9.9% complications. Intra-arterial nicardipine therapy produced clinical improvement in 42% of patients, significantly improved mean TCD velocities (P <.001) for 4 days, and was associated with no complications in our small series. We have adopted a treatment protocol at our institution of transluminal balloon angioplasty and intra-arterial nicardipine therapy as the endovascular treatments for medically refractory cerebral vasospasm.

Serum magnesium levels as related to symptomatic vasospasm and outcome following aneurysmal subarachnoid hemorrhage

INTRODUCTION

Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH.

METHODS

We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none.

RESULTS

There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels.

CONCLUSION

We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

Racial differences in demographics, acute complications, and outcomes in patients with subarachnoid hemorrhage: a large patient series

OBJECT

Few studies have focused on the impact of racial differences in demographics, clinical characteristics, acute complications, and outcomes of patients with aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to examine this issue.

METHODS

The authors evaluated prospectively collected data on 1711 adult patients with aneurysmal SAH who were entered into two randomized, double-blind, placebo-controlled trials conducted at neurosurgical centers in North America between 1991 and 1997. Admission characteristics, treatment modalities, in-hospital complications, and 3-month outcomes assessed by application of the Glasgow Outcome Scale were compared using the chi-square test, a t-test, the Wilcoxon rank-sum test, and multiple logistic regressions based on a significance level of 0.05 in 241 African-American, 1342 Caucasian, and 128 other racial minority patients. Caucasian patients were significantly older than patients of other races (p < 0.0001). African-American patients more frequently had a history of hypertension (p < 0.0001) and an elevated blood pressure at the time of admission (p < 0.0001). African-Americans and other racial minorities were more likely to have internal carotid artery aneurysms and Caucasians were more likely to have posterior circulation aneurysms (p = 0.0002). Rates of in-hospital complications were not significantly different except that pulmonary edema occurred more commonly in Caucasians (p = 0.036). After an adjustment was made for significant admission characteristics, the 3-month outcome was not significantly different among the races.

CONCLUSIONS

Race was not found to be a prognostic factor for outcome after aneurysmal SAH. The higher SAH mortality rate previously observed in African-American patients is likely a result of a higher incidence of SAH in this group. These findings highlight the importance of primary prevention programs aimed at modifying risk factors for SAH.

Risk factors for ischemic lesions following aneurysmal subarachnoid hemorrhage

Object. The aim of this study was to test whether enoxaparin treatment (40 mg subcutaneously once daily) reduces the risk of cerebral infarction after subarachnoid hemorrhage (SAH) and to investigate predictive risk factors for permanent ischemic lesions visible on follow-up computerized tomography (CT) scans obtained 3 months after SAH.

Methods. After undergoing surgery for a ruptured aneurysm, 170 patients were randomized in a prospective, double-blind, placebo-controlled trial to test the effect of enoxaparin on the occurrence of ischemic lesions, which were demonstrated on follow-up CT scans available for 156 patients. The presence of lesions correlated highly with an impaired outcome, as assessed using both the Glasgow Outcome and modified Rankin Scales (p < 0.01). Lesions occurred in 101 (65%) of the 156 patients. In half of the patients (51 patients) no lesion was visible on the CT scan obtained on the 1st postoperative day in 51 patients. On univariate analysis, the presence of lesions at 3 months post-SAH was not associated with enoxaparin treatment but did correlate with several clinical, radiological, and prehemorrhage variables. Significant independent risk factors for lesions consisted of an impaired initial clinical condition (odds ratio [OR] 2.63, 95% confidence interval [CI] 1.03–6.73), amount of subarachnoid blood (OR 6.51, 95% CI 2.27–18.65), nocturnal occurrence of SAH (that is, between 12:01 a.m. and 8:00 a.m.; OR 4.32, 95% CI 1.28–14.52), fixed symptoms of delayed ischemia (OR 5.21, 95% CI 1.02–26.49), duration of temporary artery occlusion during surgery (OR 1.66 per minute, 95% CI 1.20–2.31), and body mass index (OR 1.13/kg/m2, 95% CI 1.01–1.28).

Conclusions The presence of ischemic lesions can be predicted by the severity of bleeding, delayed cerebral ischemia, excess weight, duration of temporary artery occlusion, and occurrence of nocturnal aneurysm rupture.

Calcium antagonists for aneurysmal subarachnoid haemorrhage

BACKGROUND

Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has not been elucidated yet, but may be related to vasospasm. Experimental studies have indicated that calcium antagonists can prevent or reverse vasospasm and have neuroprotective properties. Several types of calcium antagonists have been studied in several clinical trials.

OBJECTIVES

To determine whether calcium antagonists improve outcome in patients with aneurysmal SAH.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (September 2003). In addition, we searched MEDLINE (1966 to October 2003) and EMBASE (1980 to October 2003), handsearched two Russian journals (1990 to 2003) and contacted trialists and pharmaceutical companies (in 1995 and 1996) to identify further studies.

SELECTION CRITERIA

All unconfounded, truly randomised controlled trials comparing any calcium antagonist with control.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted the data and assessed trial quality. Trialists were contacted to obtain missing information.

MAIN RESULTS

We analysed 12 trials totalling 2844 patients with SAH (1396 in the treatment group and 1448 in the control group). The drugs analysed were: nimodipine (eight trials, 1574 patients), nicardipine (two trials, 954 patients), AT877 (one trial, 276 patients) and magnesium (one trial, 40 patients). Overall, calcium antagonists reduced the risk of poor outcome: relative risk (RR) 0.82 (95% confidence interval (CI) 0.72 to 0.93); the absolute risk reduction was 5.1%, the corresponding number of patients needed to treat to prevent a single poor outcome event was 20. For oral nimodipine alone the RR was 0.70 (0.58 to 0.84). The RR of death on treatment with calcium antagonists was 0.90 (95% CI 0.76 to 1.07), that of clinical signs of secondary ischaemia 0.67 (95% CI 0.60 to 0.76), and that of CT or MR confirmed infarction 0.80 (95% CI 0.71 to 0.89).

AUTHORS' CONCLUSIONS

Calcium antagonists reduce the risk of poor outcome and secondary ischaemia after aneurysmal SAH. The results for 'poor outcome' depend largely on a single large trial with oral nimodipine; the evidence for nicardipine, AT877 and magnesium is inconclusive. The evidence for nimodipine is not beyond every doubt, but given the potential benefits and modest risks of this treatment, against the background of a devastating natural history, oral nimodipine (60 mg every 4 hours) is currently indicated in patients with aneurysmal SAH. Intravenous administration of calcium antagonists cannot be recommended for routine practice on the basis of the present evidence.

Early vasospasm on admission angiography in patients with aneurysmal subarachnoid hemorrhage is a predictor for in-hospital complications and poor outcome

BACKGROUND AND PURPOSE

Early vasospasm (EVSP), defined here as arterial narrowing seen on diagnostic angiography within the first 48 hours of aneurysmal rupture, is a rarely reported and poorly defined phenomenon in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to characterize EVSP in a large database of such patients.

METHODS

We analyzed the relationship of EVSP to clinical characteristics, in-hospital complications, and outcome at 3 months among 3478 patients entered into 4 prospective, randomized, double-blind, placebo-controlled trials of tirilazad conducted in neurosurgical centers around the world between 1991 and 1997.

RESULTS

Three hundred thirty-nine (10%) of 3478 patients had EVSP. EVSP was significantly more likely in patients with poor neurological grade on admission, history of SAH, intracerebral hematoma, larger aneurysm, thick SAH on cranial computed tomography, and intraventricular hemorrhage. EVSP was not associated with delayed cerebral vasospasm. After adjustment for differences in admission characteristics, EVSP was associated with cerebral infarction (adjusted odds ratios [OR]=1.51; 95% CI, 1.18 to 1.94; P=0.001), neurological worsening (OR=1.41; 95% CI, 1.10 to 1.81; P=0.007), and unfavorable outcome (OR=1.51; 95% CI, 1.15 to 2.00; P=0.003). In addition, there was a trend for patients with increasingly severe EVSP to have unfavorable outcome (OR=1.84 for mild and OR=2.66 for moderate/severe EVSP).

CONCLUSIONS

EVSP was seen in 10% of SAH patients and was predictive of cerebral infarction and neurological worsening as well as unfavorable outcome at 3 months. EVSP was not associated with late vasospasm. EVSP may be as important as delayed vasospasm in predicting complications and long-term morbidity in SAH patients.

The effect of nimodipine on cerebral oxygenation in patients with poor-grade subarachnoid hemorrhage

Object. Nimodipine has been shown to improve neurological outcome after subarachnoid hemorrhage (SAH); the mechanism of this improvement, however, is uncertain. In addition, adverse systemic effects such as hypotension have been described. The authors investigated the effect of nimodipine on brain tissue PO2.

Methods. Patients in whom Hunt and Hess Grade IV or V SAH had occurred who underwent aneurysm occlusion and had stable blood pressure were prospectively evaluated using continuous brain tissue PO2 monitoring. Nimodipine (60 mg) was delivered through a nasogastric or Dobhoff tube every 4 hours. Data were obtained from 11 patients and measurements of brain tissue PO2, intracranial pressure (ICP), mean arterial blood pressure (MABP), and cerebral perfusion pressure (CPP) were recorded every 15 minutes.

Nimodipine resulted in a significant reduction in brain tissue PO2 in seven (64%) of 11 patients. The baseline PO2 before nimodipine administration was 38.4 ± 10.9 mm Hg. The baseline MABP and CPP were 90 ± 20 and 84 ± 19 mm Hg, respectively. The greatest reduction in brain tissue PO2 occurred 15 minutes after administration, when the mean pressure was 26.9 ± 7.7 mm Hg (p < 0.05). The PO2 remained suppressed at 30 minutes (27.5 ± 7.7 mm Hg [p < 0.05]) and at 60 minutes (29.7 ± 11.1 mm Hg [p < 0.05]) after nimodipine administration but returned to baseline levels 2 hours later. In the seven patients in whom brain tissue PO2 decreased, other physiological variables such as arterial saturation, end-tidal CO2, heart rate, MABP, ICP, and CPP did not demonstrate any association with the nimodipine-induced reduction in PO2. In four patients PO2 remained stable and none of these patients had a significant increase in brain tissue PO2.

Conclusions. Although nimodipine use is associated with improved outcome following SAH, in some patients it can temporarily reduce brain tissue PO2.

Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage

OBJECT

This study was conducted for two purposes. The first was to determine whether a combination of measurements of subarachnoid clot volume, clearance rate, and density could improve prediction of which patients experience vasospasm. The second was to determine if each of these three measures could be used independently to predict vasospasm.

METHODS

Digital files of the cranial computerized tomography (CT) scans obtained in 75 consecutive patients admitted within 24 hours of subarachnoid hemorrhage (SAH) were analyzed in a blinded fashion by an observer who used quantitative imaging software to measure the volume of SAH and its density. Clot clearance rates were measured by quantifying SAH volume on subsequent CT scans. Vasospasm was defined as new onset of a focal neurological deficit or altered consciousness 5 to 12 days after SAH in the absence of other causes of deterioration, diagnosed with the aid of or exclusively by confirmatory transcranial Doppler ultrasonography and/or cerebral angiography. Univariate analysis showed that vasospasm was significantly associated with the SAH grade as classified on the Fisher scale, the initial clot volume, initial clot density, and percentage of clot cleared per day (p < 0.05). In multivariate analysis, initial clot volume and percentage of clot cleared per day were significant predictors of vasospasm (p < 0.05), whereas Fisher grade and initial clot density were not.

CONCLUSIONS

Quantitative analysis of subarachnoid clot shows that vasospasm is best predicted by initial subarachnoid clot volume and the percentage of clot cleared per day.

Pharmacologic Agents in Stroke Prevention, Acute Stroke Therapy, and Interventional Procedures

Pharmaceutical agents have moved far beyond just the aspirin and heparin that were the mainstays of stroke and interventional therapy as recently as 10 to 15 years ago. Our understanding of the mechanisms of thrombus formation and vascular response to damage as well as our armamentarium has tremendously improved in the past decade. Direct thrombin inhibitors, powerful antiplatelet agents, new fibrinolytic agents, and statins now allow far greater manipulation of the intraprocedural and postprocedural clot cascade and atherogenesis. It is mandatory that current-day interventionists understand the correct and appropriate use of these agents to achieve the desired outcomes of therapy.

Factors associated with the development of vasospasm after planned surgical treatment of aneurysmal subarachnoid hemorrhage

OBJECT

The goal of this study was to determine factors associated with the development of symptomatic vasospasm among patients with aneurysmal subarachnoid hemorrhage (SAH) who participated in the randomized, double-blind, placebo-controlled trials of tirilazad between 1991 and 1997.

METHODS

Data obtained from 3567 patients entered into trials of tirilazad were analyzed using uni- and multivariate logistic regression to determine factors that predict the development of symptomatic vasospasm. Symptomatic vasospasm was defined by clinical criteria accompanied by laboratory- and radiologically determined exclusion of other causes of neurological deterioration. Transcranial Doppler ultrasonographic and/or angiographic confirmation was not required. In these patients, the aneurysms were scheduled to be treated surgically, and no patient undergoing endovascular treatment was included. A multivariate analysis showed that factors significantly associated with vasospasm were age 40 to 59 years, history of hypertension, worse neurological grade, thicker blood clot on the cranial computerized tomography (CT) scan obtained on hospital admission, larger aneurysm size, presence of intraventricular hemorrhage (IVH), prophylactic use of induced hypertension, and not participating in the first European tirilazad study.

CONCLUSIONS

Symptomatic vasospasm was associated with the amount of SAH on the CT scan, the presence of IVH, and the patient's neurological grade. The association with patient age may reflect alterations in vessel reactivity associated with age. A history of hypertension may render the brain more susceptible to symptoms from vasospasm. The explanation for the relationships with aneurysm size, use of prophylactic induced hypertension, and the particular study is unclear.

Intraoperative Cerebral Angiography: Superficial Temporal Artery Method and Results

OBJECTIVE

To report the method for and results of intraoperative cerebral angiography performed via the superficial temporal artery, for assessment of cerebral aneurysm surgery.

METHODS

All patients undergoing craniotomies for treatment of intracranial aneurysms were prospectively entered into a database. A policy of performing angiography via the superficial temporal artery in appropriate cases was instituted. This procedure was performed with retrograde catheterization of the superficial temporal artery, as it coursed over the zygomatic arch, with an 18-gauge, 1.88-inch, intravenous catheter and hand injection of contrast material, with intraoperative digital subtraction fluoroscopic guidance.

RESULTS

Thirty-six patients who underwent 38 craniotomies for clipping of 43 aneurysms underwent intraoperative angiography via the superficial temporal artery. There were six unexpected findings (14%), including four unexpected arterial occlusions and two unexpected residual aneurysms. One aneurysm was observed to be patent when it was punctured, after intraoperative angiography had indicated no filling of the aneurysm. Additional clips were placed. Three patients (8%) developed multiple arterial infarctions in the territory of the injected carotid artery, for which multiple causes were possible. Adequate angiographic images could usually be obtained with this method.

CONCLUSION

Intraoperative angiography via the superficial temporal artery is simple and is not associated with substantial complications. It is a reasonable alternative to transfemoral angiography for detection of adverse consequences of intracranial aneurysm clipping.

The effect of short-term antifibrinolytic therapy on experimental vasospasm

BACKGROUND

Antifibrinolytic therapy is effective in preventing rebleeding in cases of aneurysmal subarachnoid hemorrhage (SAH). The major disadvantage of this therapy is the increase in ischemic complications, which is supposed to be due to cerebral vasospasm. In this study the effect of short-term antifibrinolytic therapy on arterial vessel narrowing after SAH was investigated utilizing the rat femoral artery vasospasm model.

METHODS

Twenty-four rats were divided into four groups of six animals each. Autologous blood (0.1 mL) was applied to the 1-cm segment of right femoral artery wrapped with a silicone cuff. In Group 1 the animals did not receive any treatment. In Groups 2, 3, and 4 150 mg/kg tranexamic acid (AMCA) was given orally for 3, 5, or 7 days respectively, starting from postoperative day 1. A 1 cm segment of each femoral artery was harvested on the 8(th) postoperative day. Morphologic analyses were performed using the parameters, radial wall thickness and cross luminal area under the light microscope. In addition, two samples from each group were examined by transmission electron microscope (TEM) to confirm the morphologic changes.

RESULTS

There was a gradual decrease in cross luminal area and gradual increase in vessel wall thickness directly proportional with time. However, the vasospastic changes that occurred in Group 2 (received AMCA for 3 days) were not significantly different from those of Group 1 (nontreated).

CONCLUSION

It was concluded that antifibrinolytic treatment for the first 3 days may prove useful in cases of clinical aneurysmal SAH. However, if this treatment is used for more than 3 days, arterial vessel narrowing is significantly increased.

Indications for endovascular therapy for refractory vasospasm after aneurysmal subarachnoid hemorrhage: experience at the University of Cincinnati

BACKGROUND

Transluminal balloon angioplasty (TBA) and intra-arterial papaverine (IAP) appear to be valuable alternatives for the treatment of aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm refractory to maximal medical therapy. Although widely used, guiding principles for the implementation of TBA and IAP are not yet established. Based on our retrospective analysis, we define guidelines for endovascular therapy for refractory vasospasm based on our clinical results, adverse effects, and pattern of vasospasm.

METHODS

Medical records of 62 patients who experienced aneurysmal SAH-induced vasospasm refractory to hypervolemic, hypertensive, hyperdynamic therapy, and who were treated with IAP or TBA were reviewed. Fifty patients met the inclusion criteria for analysis. After careful scrutiny, two types of responses to endovascular treatment were identified. On the basis of that grouping, patients were divided into two groups according to the number of arterial segments involved, that is, monoterritorial and multiterritorial vasospasm. Multiple variables were analyzed.

RESULTS

Patients undergoing multiple endovascular procedures exhibited the worst outcomes. Patients in the monoterritorial group experienced a higher incidence of clinical improvement and better outcomes after endovascular treatment. Elevated intracranial pressure (ICP) and ICP-related deaths were more prominent in the multiterritorial group of patients. Sustained ICP elevation after administration of IAP was strongly associated with poor outcome in the multiterritorial group.

CONCLUSIONS

IAP is indicated as an early potential single-dose infusion in distal monoterritorial vasospasm, if angioplasty is impossible or unsafe. The use of IAP in bilateral diffuse vasospasm is discouraged because of the high susceptibility of these patients to develop elevated ICP. Multiple IAP infusions seem to have no significant impact on patient outcome. Balloon angioplasty seems to be indicated at an early juncture in patients with multiterritorial proximal vasospasm.

Resolution of cerebral vasospasm with trapidil; an animal model

Cerebral vasospasm and rebleeding are important clinical phenomena associated with a high mortality rate. Therefore, any promising finding in the laboratory deserves assessment in clinical practice. The present study was designed to examine the possible effects of trapidil on the basilar artery of the rabbit through a cerebral vasospasm model. This experimental study was carried out on 26 adult New Zealand albino rabbits of both sexes weighing 2.5-3.0 kg. A transclival exposure was performed. Vasospasm was produced by an intracisternal injection of autologous blood. After observation of the vasospasm, trapidil was locally applied in increasing concentrations (10(-5)-10(-4) M). The effect of each concentration was measured independently after 10 minutes for each application and was extended to three hours. Trapidil was shown to have a clear spasmolytic effect on the rabbit's basilar artery. These data suggest that trapidil can have a potential use in the treatment of patients suffering from cerebral vasospasm.

Symptomatic vasospasm diagnosis after subarachnoid hemorrhage: evaluation of transcranial Doppler ultrasound and cerebral angiography as related to compromised vascular distribution

OBJECTIVE

To evaluate the reliability of transcranial Doppler ultrasound in detecting symptomatic vasospasm in patients after aneurysmal subarachnoid hemorrhage and monitoring response after hypertensive and endovascular treatments.

DESIGN

Retrospective chart review.

SETTING

Neurosciences critical care unit in a tertiary-care university hospital.

PATIENTS

All patients admitted to a neurosciences critical care unit with the diagnosis of subarachnoid hemorrhage between January 1990 and June 1997.

INTERVENTIONS

None

MEASUREMENTS AND MAIN RESULTS

We reviewed transcranial Doppler ultrasound data of 199 patients; 55 had symptomatic vasospasm. Clinical symptoms and corresponding vascular distributions were identified, as was angiographic vasospasm (n = 35). The sensitivity and specificity of transcranial Doppler ultrasound for anterior circulation vessels were calculated by using a mean cerebral blood flow velocity criterion of >120 cm/sec. Clinical diagnosis of symptomatic vasospasm was used as the standard to determine sensitivity and specificity of transcranial Doppler ultrasound and cerebral angiography. The sensitivity of transcranial Doppler ultrasound for anterior circulation in patients with symptomatic vasospasm was 73% with a specificity of 80%. The sensitivity of cerebral angiography was 80%. For individual vessels, the sensitivity and specificity of transcranial Doppler ultrasound were middle cerebral artery, 64% and 78%; anterior cerebral artery, 45% and 84%; and internal carotid artery, 80% and 77%, respectively. The mean times for symptomatic and transcranial Doppler ultrasound signs of vasospasm presentation were 6.4 +/- 2 and 6.1 +/- 3 days, respectively. In patients without symptomatic vasospasm, the mean time for mean cerebral blood flow velocities >120 cm/sec was 7.0 +/- 3 days (p <.05). Symptomatic vasospasm also was associated with thickness of clot on head computed tomography scan and rapidly increasing mean cerebral blood flow velocities. Transcranial Doppler ultrasound signs of vasospasm improved after endovascular treatment in 30 patients.

CONCLUSIONS

The reliability of transcranial Doppler ultrasound was better at detecting high mean cerebral blood flow velocities in patients with symptomatic vasospasm related to middle cerebral and internal carotid artery distributions than for anterior cerebral artery distribution. Transcranial Doppler ultrasound was as sensitive as cerebral angiography at detecting symptomatic vasospasm. High mean cerebral blood flow velocities can be apparent before the presence of symptomatic vasospasm. Daily transcranial Doppler ultrasound monitoring could provide early identification of patients with aneurysmal subarachnoid hemorrhage who are at high risk for symptomatic vasospasm and may be helpful at following success of endovascular treatment.