Advances in vasospasm treatment and prevention

Clinical management of contrast-induced neurotoxicity: a systematic review

BACKGROUND

Contrast-induced neurotoxicity (CIN) is an increasingly recognised complication following endovascular procedures utilising contrast. It remains poorly understood with heterogenous clinical management strategies. The aim of this review was to identify commonly employed treatments for CIN to enhance clinical decision making.

METHODS

A systematic search of Embase (1947-2022) and Medline (1946-2022) was conducted. Articles describing (i) patients with a clinical diagnosis of CIN, (ii) with radiological exclusion of other pathologies, (iii) detailed report of treatments, and (iv) discharge outcomes, were included. Data relating to demographics, procedure, symptoms, treatment and outcomes were extracted.

RESULTS

A total of 73 patients were included, with a median age of 64 years. The most common procedures were cerebral angiography (42.5%) and coronary angiography (42.5%), and the median volume of contrast administered was 150 ml. The most common symptoms were cortical blindness (38.4%) and reduced consciousness (28.8%), and 84.9% of patients experienced complete resolution at the time of discharge. Management included intravenous fluids to dilute contrast in the cerebrovasculature (54.8%), corticosteroids to reduce blood-brain barrier damage (47.9%), antiseizure (16.4%) and sedative (16.4%) medications. Mannitol (13.7%) was also utilised to reduce cerebral oedema. Intensive care admission was required for 19.2% of patients. No statistically significant differences were observed between treatment and discharge outcomes.

CONCLUSIONS

The clinical management of CIN should be considered on a patient-by-patient basis, but may consist of aggressive fluid therapy alongside corticosteroids, as well as other supportive therapy as required. Further examination of CIN management is required to define best practice.

Time-Dependent Inhibition of CYP2C19 by Isoquinoline Alkaloids: In Vitro and In Silico Analysis

The cytochrome P450 2C19 (CYP2C19) enzyme plays an important role in the metabolism of many commonly used drugs. Relatively little is known about CYP2C19 inhibitors, including compounds of natural origin, which could inhibit CYP2C19, potentially causing clinically relevant metabolism-based drug interactions. We evaluated a series (N = 49) of structurally related plant isoquinoline alkaloids for their abilities to interact with CYP2C19 enzyme using in vitro and in silico methods. We examined several common active alkaloids found in herbal products such as apomorphine, berberine, noscapine, and papaverine, as well as the previously identified mechanism-based inactivators bulbocapnine, canadine, and protopine. The IC50 values of the alkaloids ranged from 0.11 to 210 µM, and 42 of the alkaloids were confirmed to be time-dependent inhibitors of CYP2C19. Molecular docking and three-dimensional quantitative structure-activity relationship analysis revealed key interactions of the potent inhibitors with the enzyme active site. We constructed a comparative molecular field analysis model that was able to predict the inhibitory potency of a series of independent test molecules. This study revealed that many of these isoquinoline alkaloids do have the potential to cause clinically relevant drug interactions. These results highlight the need for studying more profoundly the potential interactions between drugs and herbal products. When further refined, in silico methods can be useful in the high-throughput prediction of P450 inhibitory potential of pharmaceutical compounds.

Highly flexible and rapidly degradable papaverine-loaded electrospun fibrous membranes for preventing vasospasm and repairing vascular tissue

Vasospasm is a common post-operative complication after vascular anastomosis. Currently, the main treatment is a local injection of antispasmodic drugs. However, this method has a high rate of relapse and is subject to a large degree of individual variation, and repeated injections cause additional pain for patients. In this study, we developed highly flexible and rapidly degradable papaverine-loaded electrospun fibrous membranes to be wrapped around vascular suturing to prevent vasospasm. Poly-l-lactic acid/polyethylene glycol (PLLA/PEG) electrospun fibers containing papaverine maintained a high degree of flexibility and could withstand any folding, and are therefore suitable for wrapping vascular suturing. A rapid release of papaverine, between 2 and 7 days, was achieved by adjusting the proportions of PEG and PLLA. PLLA electrospun fibers containing 40% PEG (PLLA-40%) could control drug release and polymer degradation most effectively during the first 2 weeks post-operation. Testing using an in vivo rabbit model showed that PLLA-40% fibrous membranes produced significant antispasmodic effect without observable inflammation or hyperplasia, and the fibrous membranes were ideally biodegradable, with no impact on regional blood flow, pressure, vessel diameter or surrounding tissue hyperplasia. Therefore, papaverine-loaded electrospun fibrous membranes show the potential to greatly reduce post-operative vasospasm and maintain regular vascular morphology during antispasmodic therapy.

Vasospasm after aneurysmal subarachnoid hemorrhage: recent advances in endovascular management

PURPOSE OF REVIEW

In a rapidly advancing specialty, it is essential to review the recent studies of alternative new treatments and present their efficacy, safety and outcome. We discuss the recent advances in the endovascular treatment of cerebral vasospasm following aneurysmal subarachnoid hemorrhage in the past few years with special focus on the literature regarding this subject in the last 18-24 months.

RECENT FINDINGS

The recent findings are as follows: effect of papaverine on brain oxygen; recent evaluation concerning nimodipine use; combined intraarterial and intravenous use of milrinone; illustration of the numerous recent studies on nicardipine; the safety and efficacy of high-dose intraarterial verapamil; outcome and adverse effects of intraarterial fasudil; transluminal balloon angioplasty; and recent evaluation of its efficacy and evaluation of its prophylactic use.

SUMMARY

Endovascular treatment, including intraarterial vasodilators and transluminal balloon angioplasty, has a very important place in the management of symptomatic vasospasm related to aneurysmal subarachnoid hemorrhage. The efficacy of intraarterial vasodilators has been proven. Numerous studies and analysis of different treatments of cerebrovascular vasospasm took place in the past period. This allowed more understanding and evaluation of their outcome, safety and efficacy helping physicians to choose better treatments to adopt. It emphasizes also the aspects that need more study and research.

Trehalose treatment suppresses inflammation, oxidative stress, and vasospasm induced by experimental subarachnoid hemorrhage

Background

Subarachnoid hemorrhage (SAH) frequently results in several complications, including cerebral vasospasm, associated with high mortality. Although cerebral vasospasm is a major cause of brain damages after SAH, other factors such as inflammatory responses and oxidative stress also contribute to high mortality after SAH. Trehalose is a non-reducing disaccharide in which two glucose units are linked by α,α-1,1-glycosidic bond, and has been shown to induce tolerance to a variety of stressors in numerous organisms. In the present study, we investigated the effect of trehalose on cerebral vasospasm, inflammatory responses, and oxidative stress induced by blood in vitro and in vivo.

Methods

Enzyme immunoassay for eicosanoids, pro-inflammatory cytokines, and endothelin-1, and western blotting analysis for cyclooxygenase-2, inducible nitric oxide synthase, and inhibitor of NF-κB were examined in macrophage-like cells treated with hemolysate. After treatment with hemolysate and hydrogen peroxide, the levels of lipid peroxide and amounts of arachidonic acid release were also analyzed. Three hours after the onset of experimental SAH, 18 Japanese White rabbits received an injection of saline, trehalose, or maltose into the cisterna magna. Angiographic and histological analyses of the basilar arteries were performed. In a separate study, the femoral arteries from 60 rats were exposed to fresh autologous blood. At 1, 3, 5, 7, 10, and 20 days after treatment, cryosections prepared from the femoral arteries were histologically analyzed.

Results

When cells were treated with hemolysate, trehalose inhibited the production of several inflammatory mediators and degradation of the inhibitor of NF-κB and also suppressed the lipid peroxidation, the reactive oxygen species-induced arachidonic acid release in vitro. In the rabbit model, trehalose produced an inhibitory effect on vasospasm after the onset of experimental SAH, while maltose had only a moderate effect. When the rat femoral arteries exposed to blood were investigated for 20 days, histological analysis revealed that trehalose suppressed vasospasm, inflammatory response, and lipid peroxidation.

Conclusions

These data suggest that trehalose has suppressive effects on several pathological events after SAH, including vasospasm, inflammatory responses, and lipid peroxidation. Trehalose may be a new therapeutic approach for treatment of complications after SAH.

From vasospasm to early brain injury: new frontiers in subarachnoid haemorrhage research

INTRODUCTION

Delayed vasospasm has traditionally been considered the most important determinant of poor outcome after subarachnoid haemorrhage (SAH). Consequently, most of the research and therapies are directed towards reducing the incidence of vasospasm (VSP). To date, however, clinical trials based on this strategy have not delivered a definitive treatment for preventing or reducing brain injury after SAH. This fact has caused a paradigm shift in research, which now focuses on early brain injury (EBI) occurring in the first 72 hours after SAH. It has also changed the idea of VSP's role in brain damage, and suggests the need for re-evaluating the pathophysiological process of SAH.

DEVELOPMENT

This review examines the current state of knowledge on the pathophysiological mechanisms associated with EBI and summarises the diagnostic options currently available.

CONCLUSION

It seems that the research approach needs to be changed so that investigators will focus on prevention of EBI, reduction of secondary brain complications and ultimately, the optimisation neurological outcome.

The role of intravenous immunoglobulin in the treatment of cerebral vasospasm induced by subarachnoid haemorrhage: an experimental study

OBJECTIVES

The aim of this study was to determine whether intravenous immunoglobulin (IVIG) prevents cerebral vasospasm in rabbits with induced subarachnoid haemorrhage (SAH). The effect of IVIG on apoptosis in the endothelial cells of the basilar artery was also evaluated.

METHODS

Eighteen New Zealand white rabbits were allocated randomly into three groups. SAH was induced by injecting autologous blood into the cisterna magna. Group 1, the control group, was subjected to sham surgery (no induction of SAH). Group 2 had SAH alone and Group 3 had SAH plus IVIG. Three days after treatment, the animals were sacrificed. The basilar artery tissues were analysed histologically and the malondialdehyde levels in the brain stem tissues were evaluated biochemically.

RESULTS

Differences in the histopathological luminal areas and full wall thicknesses in the SAH plus IVIG group and the SAH group were statically insignificant (p > 0.005). The malondialdehyde level was also found to be lower in the IVIG group than in the SAH group, although this difference was not significant (p > 0.005).

CONCLUSION

Although the IVIG treatment was revealed to have no vasodilator effect on the SAH-induced spastic basilar artery, it was shown to have a beneficial effect on the apoptosis of endothelial cells, probably via anti-inflammatory mechanisms.

[Protective measures against cerebral ischemia following subarachnoid hemorrhage: Part 1]

BACKGROUND AND OBJECTIVES

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage contributes significantly to morbidity and mortality. Many studies on the various treatments aimed at preventing cerebral vasospasm have been carried out, but evidence of efficacy is limited. Our aim was to review the literature on the various therapies for which there is scientific evidence of protection against cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

METHODS

MEDLINE search (1950 to the october 2009) and review of articles found on the prevention of cerebral vasospasm following aneurysmal subarachnoid hemorrhage. The search was restricted to articles in English, French, and Spanish. The keywords were cerebral vasospasm, subarachnoid hemorrhage, therapy, nimodipine, triple H, clazosentan, statins, and magnesium in addition to the word forms derived from them. We also searched manually for references cited in the selected articles. A title was included if it was a randomized controlled trial, meta-analysis, nonrandomized clinical trial, descriptive study, observational study with statistical analysis, opinion article, or expert review.

RESULTS

Part 1 analyzed treatment with calcium antagonists and triple-H therapy (hypertension, hemodilution, and hypervolemia). Part 2 analyzed new therapies such as clazosentan, magnesium, and statins. A total of 597 titles were located; 283 were initially selected. The 61 articles finally selected for review were of the following types: 2 opinion articles, 21 randomized controlled trials, 22 expert review articles, 3 meta-analyses, 4 nonrandomized clinical trials, 1 descriptive study, and 5 observational studies with statistical analysis. Three studies (2 meta-analyses and 1 randomized controlled trial) demonstrated that nimodipine use confers benefits (reduced morbidity and mortality) for patients with aneurysmatic subarachnoid hemorrhage. Statistically significant clinical benefits could not be demonstrated for the other drugs (clazosentan, statins, and magnesium).

CONCLUSIONS

Insufficient evidence is available to support the use of the triple-H therapy, clazosentan, statins, or magnesium sulfate for the prevention of cerebral vasospasm following subarachnoid hemorrhage. Nimodipine is the only preventative treatment that can be recommended.

Intracortical EEG for the detection of vasospasm in patients with poor-grade subarachnoid hemorrhage

BACKGROUND

To study the feasibility of utilizing intracortical electroencephalography (ICE) including quantitative EEG (qEEG) analysis for the detection of vasospasm in five consecutive poor-grade SAH patients.

METHODS

Intracortical electroencephalography (ICE) was obtained via a single miniature parenchymal 8-contact depth electrode placed at the bedside. Quantitative EEG parameters, calculated on surface EEG and ICE, included alpha/delta ratio (ADR), mean amplitude, suppression percent, and total power. Percent changes between averaged values over 4-6 h of baseline EEG and EEG prior to angiography were calculated. The entire continuous qEEG recording for each patient was then reviewed to determine optimal automated alarm criteria.

RESULTS

ICE ADR was the most accurate for predicting angiographic vasospasm (5/5). ICE ADR decreased between baseline and follow-up by 42% (from 0.56 ± 0.07 to 0.32 ± 0.03) for those with vasospasm (N = 3) compared to 17% (0.62 ± 0.06 to 0.51 ± 0.03) for those without (N = 2). A sustained decrease in the ICE ADR from baseline (>25% for ≥ 4 h) occurred in all three patients with angiographically confirmed vasospasm and not in the two without; this decline occurred 1-3 days prior to angiographic confirmation.

CONCLUSIONS

Intracortical EEG is promising for detecting ischemia from vasospasm in poor-grade SAH patients, may be superior to scalp EEG, and allow automated detection, particularly using the ADR. Larger studies are needed to better define the effectiveness of this approach.

High-Dose Intra-arterial Verapamil for the Treatment of Cerebral Vasospasm After Subarachnoid Hemorrhage

BACKGROUND:

Studies attempting to establish the safety and efficacy of standard and high-dose intra-arterial infusions of calcium channel blockers for treatment of cerebral vasospasm have focused on hemodynamic changes during the angiographic procedure.

OBJECTIVE:

To evaluate longer-term drug effects over the hours following infusion and the effects on brain tissue oxygen tension or cerebral metabolism.

METHODS:

We studied 11 patients with poor-grade aneurysmal subarachnoid hemorrhages who underwent multimodality brain monitoring and angiography with infusion of high-dose intra-arterial verapamil (≥15 mg total dose). Hourly intracerebral microdialysis measurements and continuously recorded mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), and Pbto2 were analyzed for 6 hours before and 12 hours following treatment.

RESULTS:

A median dose of 23 mg (range, 15-55 mg) of intra-arterial verapamil was given. Compared with baseline values, reductions in CPP and MAP were maximal at 3 hours postangiography (from 105 ± 13 mm Hg to 95 ± 15 mm Hg and from 116 ± 12 mm Hg to 106 ± 16 mm Hg, P < .01) and persisted for up to 6 hours (P < .04); increases in vasopressor therapy were required in 8 procedures (53%). ICP significantly increased during the first 3 hours post angiography (P < .03). Brain glucose increased by 33% by hour 9 (P < .001). There were no significant changes in Pbto2 or the lactate/pyruvate ratio.

CONCLUSION:

High-dose intra-arterial verapamil causes increases in ICP and reductions in CPP, followed by an increase in brain glucose levels, without altering brain oxygen tension or oxidative metabolism. Patients undergoing high-dose intra-arterial verapamil therapy warrant close hemodynamic and ICP monitoring for at least 12 hours following treatment.

Costs of vasospasm in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

To assess the impact of vasospasm on costs, length of stay, and mortality among inpatients with aneurysmal subarachnoid hemorrhage.

METHODS

We combined hospital accounting and physician billing data for a consecutive cohort of 198 patients who underwent surgical clipping or endovascular coiling for subarachnoid hemorrhage repair. We considered patients with transcranial Doppler (TCD) velocity of 120 cm/s or greater in the middle cerebral artery to have TCD-defined vasospasm and patients with delayed ischemic neurological deficit to have symptomatic vasospasm. We compared outcomes of patients with TCD-defined vasospasm (n = 116) and those without (n = 73) and patients with symptomatic vasospasm (n = 62) and those without (n = 127), adjusting for demographic and clinical characteristics.

RESULTS

In adjusted analyses, the incremental cost attributable to TCD-defined vasospasm was 1.20 times higher (95% confidence interval, 1.06-1.36; P = .004) than for patients without TCD-defined vasospasm. Length of stay was an estimated 1.22 times longer for patients with TCD-defined vasospasm (95% CI, 1.07-1.39; P < .01). For symptomatic vasospasm, adjusted costs were 1.27 times higher (95% CI, 1.12-1.43; P < .001) and length of stay was an estimated 1.24 times longer (95% CI, 1.09-1.40; P < .01) for patients with vasospasm than for those without. There was no significant relationship between either type of vasospasm and in-hospital mortality.

CONCLUSION

Patients with subarachnoid hemorrhage and TCD-defined or symptomatic vasospasm incur higher inpatient costs and longer hospital stays than those without vasospasm.

Comparison of intrathecal cilostazol and nimodipine treatments in subarachnoid hemorrhage: an experimental study in rabbits

OBJECTIVE

intrathecal administration of calcium channel antagonists has been proposed to reduce cerebral vasospasm (CVS) in animal subarachnoid hemorrhage (SAH) models. Also, delayed CVS treatment model with oral administration of cilostazol can be seen in the literature.

METHODS

in this study, 25 male New Zealand white rabbits were randomly assigned to five groups: control, SAH only, SAH/nimodipine, SAH/cilostazol, SAH/vehicle. The animals' basilar arteries were sectioned from four separate zones and four sections were obtained from each rabbit. Basilar artery luminal section areas were measured by using SPOT for windows Version 4.1 computer program.

RESULTS

basilar artery luminal section areas in SAH/ nimodipine and SAH/ cilostazol groups were significantly higher than SAH only group (P < 0.05).

CONCLUSION

phosphodiesterase 3 inhibitor cilostazol has vasodilatory effects without affecting cerebral blood flow. Nimodipine is a calcium channel blocker and is still used in vasospasm therapy either oral or intravenously. This study demonstrates that prophylactic bolus intrathecal administration of either cilostazol or nimodipine equally prevents SAH-associated CVS in an animal model. We therefore propose that cilostazol is a candidate for clinical trials in the treatment of delayed vasospasm.

A review of delayed ischemic neurologic deficit following aneurysmal subarachnoid hemorrhage: historical overview, current treatment, and pathophysiology

Delayed ischemic neurologic deficit (DIND) is a serious and poorly understood complication of aneurysmal subarachnoid hemorrhage. Although advances in treatment have improved prognosis for these patients, long-term clinical outcomes remain disappointing. Historically, angiographic vasospasm was thought to result in a DIND, although an increasing body of evidence suggests that this is an oversimplification, because interventions that have effectively targeted angiographic vasospasm have not improved outcome. Consequently, the relationship between angiographic vasospasm and neurologic outcome may be associative rather than causative. Although our understanding of the underlying molecular processes and pathophysiology is improving, responsible mediators or pathways have yet to be identified. The aim of this review is to summarize the key historical events that have helped shape our understanding of the pathophysiology of this phenomenon (microcirculation, autoregulation, microthrombosis, inflammation, apoptosis, spreading depolarization, oxidative stress) and to present the evidence underlying current treatment strategies (hemodynamic therapy, oral nimodipine, endovascular therapy, statins, cerebrospinal fluid drainage, thrombolysis, magnesium) and the translational and clinical research investigating DIND.

Potential role of CD34 in cerebral vasospasm after experimental subarachnoid hemorrhage in rats

Inflammatory responses have been implicated in the elaboration of several forms of central nervous system injury, including cerebral vasospasm after subarachnoid hemorrhage (SAH). A critical event participating in such responses is the recruitment of circulating leukocytes into the inflammatory site. CD34 is a key adhesion molecule responsible for recruitment of monocytes/macrophages and the attachment of leukocytes to endothelial cells. However, it has not been investigated whether, and to what degree, CD34 is induced by SAH and also the role of CD34 in the pathogenesis of cerebral vasospasm following SAH remains unknown. Experiment 1 aimed to investigate the timecourse of the CD34 expression in the basilar artery after SAH. In experiment 2, we chose the maximum time point of vasospasm (day 3) and assessed the effect of monoclonal antibody against CD34 on regulation of cerebral vasospasm. As a result, the elevated expression of CD34 was detected in the basilar artery after SAH and peaked on day 3. After intracisternal administration of CD34 monoclonal antibody, the vasospasm was markedly attenuated after blood injection on day 3. Our results suggest that CD34 is increasingly expressed in a parallel time course to the development of cerebral vasospasm in a rat experimental model of SAH and administration of the specific CD34 antibody could prevent or reduce cerebral vasospasm caused by SAH.

Platelet-derived growth factor-induced severe and chronic vasoconstriction of cerebral arteries: proposed growth factor explanation of cerebral vasospasm

OBJECTIVE

After subarachnoid hemorrhage (SAH), platelet-derived growth factor-BB (PDGF-BB) is secreted in and around the cerebral arteries. To clarify the role of PDGF-BB in the development of vasospasm after SAH, we determined whether PDGF-BB alone can cause long-lasting vasoconstriction of a severity similar to that of vasospasm. In addition, the anti-vasospastic effect of trapidil, an antagonist of PDGF-BB function, was investigated.

METHODS

We infused recombinant PDGF-BB (10 microg/mL saline as the vehicle) (n = 14) into the subarachnoid space of rabbits and analyzed alterations in the caliber of the basilar artery using repeated angiography. To study the role of PDGF-BB on the development of vasospasm, trapidil was administered continuously starting 1 hour after SAH, on day 0 (0.63-1.25 mg/kg /h or vehicle) for 47 hours (n = 24), or after the full development of cerebral vasospasm on day 2 (3.0 mg/kg/h or vehicle) for 0.5 hours (n = 17), and alterations in the caliber of the basilar artery were monitored.

RESULTS

PDGF-BB caused long-lasting vasoconstriction, with maximum constriction of 56% (P < .001) of the control value (= 100%) on day 2, resembling vasospasm seen after SAH. Prolonged administration of intravenous trapidil, starting soon after SAH, prevented the development of vasospasm in a dose-dependent manner (P < .05, .01, or .001). Intravenous or intra-arterial administration of trapidil significantly dilated vasospasm (P < .01) on day 2, at least transiently.

CONCLUSION

PDGF-BB, a growth factor synthesized in the subarachnoid space after SAH, can cause severe and long-lasting vasoconstriction. Significant prevention and resolution of vasospasm can be achieved by the PDGF-BB antagonist trapidil. We propose that excessive production of PDGF-BB, essentially aiming to repair injured arteries, causes cerebral vasospasm. Although the half-life of trapidil in serum may be shorter than that of PDGFG-BB-derived spasmogenic signaling, trapidil is a candidate drug for constructing a new therapeutic modality for preventing and resolving vasospasm.

Relationship between brain interstitial fluid tumor necrosis factor-α and cerebral vasospasm after aneurysmal subarachnoid hemorrhage

Tumor necrosis factor-alpha (TNF-alpha) has a crucial role in the onset of hemolysis-induced vascular injury and cerebral vasoconstriction. We hypothesized that TNF-alpha measured from brain interstitial fluid would correlate with the severity of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH). From a consecutive series of 10 aSAH patients who underwent cerebral microdialysis (MD) and evaluation of vasospasm by CT angiogram (CTA) or digital subtraction angiography (DSA), TNF-alpha levels from MD were measured at 8-hour intervals from aSAH days 4-6 using enzyme-linked immunosorbent assay. An attending neuroradiologist blinded to the study independently evaluated each CTA and DSA and assigned a vasospasm index (VI). Five patients had a VI<2 and 5 patients had a VI>2, where the median VI was 2 (range 0-13). The median log TNF-alpha area under the curve (AUC) was 1.64pg/mL *day (interquartile range 1.48-1.71) for the VI<2 group, and 2.11pg/mL *day (interquartile range 1.95-2.47) for the VI>2 group (p<0.01). Thus, in this small series of poor-grade aSAH patients, the AUC of TNF-alpha levels from aSAH days 4-6 correlates with the severity of radiographic vasospasm. Further analysis in a larger population is warranted based on our preliminary findings.

Therapeutic approaches to cerebral vasospasm complicating ruptured aneurysm

Cerebral vasospasm is a serious complication of ruptured aneurysm. In order to avoid short- and long-term effects of cerebral vasospasm, and as there is no single or optimal treatment modality employed, we have instituted a protocol for the prevention and treatment of vasospasm in patients suffering aneurysmal sub-arachnoid hemorrhage (SAH). We then reviewed the effectiveness of this protocol in reducing the mortality and morbidity rate in our institution. In this study we present a retrospective analysis of 52 cases. Between March 2004 and December 2008 52 patients were admitted to our service with aneurysmal SAH. All patients commenced nimodipine, magnesium sulphate (MgSO₄) and triple H therapy. Patients with significant reduction in conscious level were intubated, ventilated and sedated. Intracranial pressure (ICP) monitoring was used for intubated patients. Sodium thiopental coma was induced for patients with refractory high ICP; angiography was performed for diagnosis and treatment. Balloon angioplasty was performed if considered necessary. Using this protocol, only 13 patients (25%) developed clinical vasospasm. Ten of them were given barbiturates to induce coma. Three patients underwent transluminal balloon angioplasty. Four out of 52 patients (7.7%) died from severe vasospasm, 3 patients (5.8%) became severely disabled, and 39 patients (75%) were discharged in a condition considered as either normal or near to their pre-hemorrhage status. Our results confirm that the aforementioned protocol for treatment of cerebral vasospasm is effective and can be used safely.

Complement activation and disease: protective effects of hyperbilirubinaemia

Complement, an important effector mechanism of the immune system, is an enzymatic cascade of approx. 30 serum proteins leading to the amplification of a specific humoral response. It can be activated through the classical or alternative pathways, or through the mannose-binding lectin pathway. The activation of the classical pathway is initiated by the binding of the C1 component to antigen-bound antibodies, known as immunocomplexes. C1 is a complex of one molecule of C1q, two molecules of C1r and two molecules of C1s. C1q contains three copies of a Y-shaped fundamental unit with globular heads included in its structure, which play a major role in the interaction with the Fc portion of immunoglobulins. Deficient or exacerbated activation of the complement system leads to diseases of variable severity, and pharmacological inhibition of the complement system is considered as a therapeutic strategy to ameliorate the inflammatory effects of exacerbated complement activation. Bilirubin is a product of haem degradation by the concerted action of haem oxygenase, which converts haem into biliverdin, and biliverdin reductase, which reduces biliverdin to UCB (unconjugated bilirubin). UCB exerts both cytoprotective and cytotoxic effects in a variety of tissues and cells, acting either as an antioxidant at low concentrations or as an oxidant at high concentrations. In the present review, we describe in detail the anti-complement properties of bilirubin, occurring at levels above the UCB concentrations found in normal human serum, as a beneficial effect of potential clinical relevance. We provide evidence that UCB interferes with the interaction between C1q and immunoglobulins, thus inhibiting the initial step in the activation of complement through the classical pathway. A molecular model is proposed for the interaction between UCB and C1q.

Continuous electroencephalogram monitoring in the intensive care unit

Because of recent technical advances, it is now possible to record and monitor the continuous digital electroencephalogram (EEG) of many critically ill patients simultaneously. Continuous EEG monitoring (cEEG) provides dynamic information about brain function that permits early detection of changes in neurologic status, which is especially useful when the clinical examination is limited. Nonconvulsive seizures are common in comatose critically ill patients and can have multiple negative effects on the injured brain. The majority of seizures in these patients cannot be detected without cEEG. cEEG monitoring is most commonly used to detect and guide treatment of nonconvulsive seizures, including after convulsive status epilepticus. In addition, cEEG is used to guide management of pharmacological coma for treatment of increased intracranial pressure. An emerging application for cEEG is to detect new or worsening brain ischemia in patients at high risk, especially those with subarachnoid hemorrhage. Improving quantitative EEG software is helping to make it feasible for cEEG (using full scalp coverage) to provide continuous information about changes in brain function in real time at the bedside and to alert clinicians to any acute brain event, including seizures, ischemia, increasing intracranial pressure, hemorrhage, and even systemic abnormalities affecting the brain, such as hypoxia, hypotension, acidosis, and others. Monitoring using only a few electrodes or using full scalp coverage, but without expert review of the raw EEG, must be done with extreme caution as false positives and false negatives are common. Intracranial EEG recording is being performed in a few centers to better detect seizures, ischemia, and peri-injury depolarizations, all of which may contribute to secondary injury. When cEEG is combined with individualized, physiologically driven decision making via multimodality brain monitoring, intensivists can identify when the brain is at risk for injury or when neuronal injury is already occurring and intervene before there is permanent damage. The exact role and cost-effectiveness of cEEG at the current time remains unclear, but we believe it has significant potential to improve neurologic outcomes in a variety of settings.

Endovascular options in the treatment of delayed ischemic neurological deficits due to cerebral vasospasm

The second leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (SAH) is delayed cerebral ischemia due to vasospasm. Although up to 70% of patients have been shown to have angiographic evidence of vasospasm, only 20-30% will present with clinical changes, including mental status changes and neurological deficits that necessitate acute management. Endovascular capabilities have progressed to become viable options in the treatment of cerebral vasospasm. The rationale for intraarterial therapy includes the fact that morbidity and mortality rates have not changed in recent years despite optimized noninvasive medical care. In this report, the authors discuss the most common endovascular options-namely intraarterial vasodilators and transluminal balloon angioplasty-from the standpoint of mechanism, efficacy, limitations, and complications as well as the treatment algorithms for cerebral vasospasm used at our institution.

Pathogenesis of cerebral vasospasm following aneurysmal subarachnoid hemorrhage: putative mechanisms and novel approaches

Cerebral vasospasm is a potentially incapacitating or lethal complication in patients with aneurysmal subarachnoid hemorrhage (SAH). The development of effective preventative and therapeutic interventions has been largely hindered by the fact that the underlying pathogenic mechanisms of cerebral vasospasm remain poorly understood. However, intensive research during the last 3 decades has identified certain mechanisms that possibly play a role in its development. Experimental data suggest that calcium-dependent and -independent vasoconstriction is taking place during vasospasm. It appears that the breakdown products of blood in the subarachnoid space are involved, through direct and/or indirect pathways, in the development of vasospasm after SAH. Free radicals reactions, an imbalance between vasoconstrictor and vasodilator substances (endothelium derived substances, e.g., nitric oxide, endothelin; arachidonic acid metabolites, e.g., prostaglandins, prostacyclin), inflammatory processes, an upheaval of neuronal mechanisms that regulate vascular tone, endothelial proliferation, and apoptosis have all been put forward as causative and/or pathogenic factors. Translational research in the field of vasospasm has traditionally aimed to identify agents/interventions in order to block the cascades initiated after SAH. The combination of novel approaches such as cerebral microdialysis, magnetic resonance spectroscopy, proteomics, and lipidomics could serve a dual purpose: elucidating the complex pathobiochemistry of vasospasm and providing clinicians with tools for early detection of this feared complication. The purpose of this Mini-Review is to provide an overview of the pathogenesis of cerebral vasospasm and of novel approaches used in basic and translational research.

Intracranial vasospasm with subsequent stroke after traumatic subarachnoid hemorrhage in a 22-month-old child

Clinical and radiographic evidence of subarachnoid hemorrhage (SAH)-related vasospasm is rare in children and has not been reported in infants. In this report the authors present the case of a 22-month-old child who developed clinically symptomatic, radiographically identifiable vasospasm after traumatic SAH. To the authors' knowledge, this is the first report of vasospasm associated with SAH in a child this young. This 22-month-old boy fell and had a dense SAH. He had a history of surgically corrected craniosynostosis and nonsymptomatic ventriculomegaly. The boy was evaluated for occult vascular lesions using imaging; none were found and normal vessel caliber was noted. Ten days later, the child developed left-sided weakness and a right middle cerebral artery infarct was identified. Evaluation disclosed significant intracranial vasospasm. This diagnosis was supported by findings on CT angiography, transcranial Doppler ultrasonography, MR imaging, and conventional angiography. The child was treated using intraarterial verapamil with a good result, as well as with conventional intensive care measures to reduce vasospasm. This report documents the first known case of intracranial vasospasm with stroke after SAH in a patient under the age of 2 years. This finding is important because it demonstrates that the entity of SAH-associated vasospasm can affect the very young, widening the spectrum of ages susceptible to this condition. This case is also important because it demonstrates that even very young children can respond to conventional therapeutic interventions such as intraarterial verapamil. Thus, clinicians need to be alert to the possibility of vasospasm as a potential diagnosis when evaluating young children with SAH.

X pentasomy in an intracytoplasmic sperm injection pregnancy detected by nuchal translucency testing

Althoughmaternally derived X pentasomy following intracytoplasmic sperm injection (ICSI) is rare, prenatal detection of a case offers insight into etiology and diagnosis. A 29-year-old gravida 1 whose pregnancy resulted from ICSI was referred for ultrasound screening at 11 weeks' gestation. Nuchal translucency thickness was 3.2 mm, and the fetal nasal bone was absent. Subsequent evaluation revealed karyotype 49,XXXXX. DNA microsatellite analysis showed the extra X chromosomes were maternal in origin. Termination of pregnancy was performed at 15 weeks. Because of the increased risk of sex chromosomal abnormalities in ICSI pregnancies, patients should be counseled prior to fertilization and standard prenatal care should include nuchal translucency measurement and any other elements necessary for indicated pregnancies to obtain a diagnosis.

Novel treatments for cerebral vasospasm following aneurysmal subarachnoid hemorrhage

Cerebral vasospasm is a major cause of cerebral ischemia and poor outcomes in the setting of aneurysmal subarachnoid hemorrhage (SAH). Despite advances in diagnosis and treatment of SAH, the pathophysiology of vasospasm is still poorly understood and outcomes remain disappointing. Recent advances in understanding the role of hemoglobin in initiating an inflammatory cascade in the subarachnoid space open new avenues for therapy. Preliminary experimental and clinical evidence indicate that targets in the inflammatory and oxidative cascades hold promise in reducing the incidence and impact of cerebral vasospasm.