Clinical, laboratory, and radiographic predictors of the occurrence of seizures following aneurysmal subarachnoid hemorrhage

Effect of plasma transfusion on in-hospital mortality and morbidities in patients with spontaneous subarachnoid hemorrhage

OBJECTIVE

Spontaneous subarachnoid hemorrhage (SAH) is a critical condition in which patients may require plasma transfusion during hospitalization. However, it remains unknown whether plasma administration has detrimental effects on the prognosis of SAH beyond the correction of coagulopathy or hypovolemia. This study aimed to analyze the association of plasma transfusion with in-hospital mortality and morbidities in patients with SAH.

METHODS

We retrospectively analyzed the data of 1689 adult patients with a primary diagnosis of spontaneous SAH. Differences in the clinical parameters were evaluated between patients who received plasma transfusion and those who did not.

RESULTS

Of 1689 patients, 158 (9.4%) received plasma transfusion. Statistical analysis revealed significant differences in pre-existing comorbidity prevalence between the two study groups. The post-SAH morbidities, including cerebral ischemic events (13.3% vs. 6.4%; p = 0.01), were more common in the plasma transfusion group, whereas the mortality rate was not different between the two study groups (p = 0.166). The mean duration of hospital stay was 19.3 ± 14.4 days and 15.1 ± 15.2 days for patients with and without plasma transfusion, respectively (p = 0.001).

CONCLUSION

Plasma transfusion following spontaneous SAH is not uncommon. Although the in-hospital mortality rate does not increase following plasma transfusion, cerebral ischemic events as well as other morbidities are more frequent in patients receiving plasma transfusion. Therefore, the indication for plasma transfusion following SAH needs careful weighing and should be further defined by well-controlled studies.

Long-term Risk of Epilepsy in Subarachnoid Hemorrhage Survivors With Positive Family History: A Population-Based Follow-up Study

BACKGROUND AND OBJECTIVES

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating form of stroke affecting the working-age population, where epilepsy is a common complication and major prognostic factor for increased morbidity in aSAH survivors. The objective of this analysis was to assess whether epilepsy in first-degree relatives is a risk of developing epilepsy after aSAH.

METHODS

We used a region-specific database that includes all cases of unruptured and ruptured saccular intracranial aneurysm admitted to Kuopio University Hospital from its defined Eastern Finnish catchment population. We also retrieved data from Finnish national health registries for prescription drug purchases and reimbursement, hospital discharge, and cause of death and linked them to patients with aSAH, their first-degree relatives, and population controls matched 3:1 by age, sex, and birth municipality. Cox regression modeling and Kaplan-Meier survival curves were used for analysis.

RESULTS

We examined data for 760 consecutive 12-month survivors of aSAH, born in 1950 or after, with a first aSAH from January 1, 1995, to December 31, 2018. Of the 760 patients (median age, 47 years; 53% female; median follow-up, 11 years), 111 (15%) developed epilepsy at a median of 7 months (interquartile range, 2-14 months) after admission for aSAH. Of the 2,240 population controls and 4,653 first-degree relatives of patients with aSAH, 23 (0.9%) and 80 (1.7%), respectively, developed epilepsy during the follow-up period. Among 79 patients with epilepsy in first-degree relatives, 22 (28%) developed epilepsy after aSAH; by contrast, among 683 patients with no epilepsy in first-degree relatives, 89 (13%) developed epilepsy after aSAH. Having at least 1 relative with epilepsy was an independent risk factor of epilepsy after aSAH (hazard ratio, 2.44; 95% CI 1.51-3.95). Cumulative 1-year rates by first-degree relationship were 40% with 1 or more children with epilepsy, 38% with 1 or more affected parents, 5% with 1 or more affected siblings, and 10% with no relatives with epilepsy.

DISCUSSION

Patients who developed epilepsy after aSAH were significantly more likely to have first-degree relatives with epilepsy than those who did not develop epilepsy after the aSAH.

Volumetric quantification of aneurysmal subarachnoid hemorrhage independently predicts hydrocephalus and seizures

OBJECTIVE

Hydrocephalus and seizures greatly impact outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH); however, reliable tools to predict these outcomes are lacking. The authors used a volumetric quantitative analysis tool to evaluate the association of total aSAH volume with the outcomes of shunt-dependent hydrocephalus and seizures.

METHODS

Total hemorrhage volume following aneurysm rupture was retrospectively analyzed on presentation CT imaging using a custom semiautomated computer program developed in MATLAB that employs intensity-based k-means clustering to automatically separate blood voxels from other tissues. Volume data were added to a prospectively maintained aSAH database. The association of hemorrhage volume with shunted hydrocephalus and seizures was evaluated through logistic regression analysis and the diagnostic accuracy through analysis of the area under the receiver operating characteristic curve (AUC).

RESULTS

The study population comprised 288 consecutive patients with aSAH. The mean total hemorrhage volume was 74.9 ml. Thirty-eight patients (13.2%) developed seizures. The mean hemorrhage volume in patients who developed seizures was significantly higher than that in patients with no seizures (mean difference 17.3 ml, p = 0.01). In multivariate analysis, larger hemorrhage volume on initial CT scan and hemorrhage volume > 50 ml (OR 2.81, p = 0.047, 95% CI 1.03-7.80) were predictive of seizures. Forty-eight patients (17%) developed shunt-dependent hydrocephalus. The mean hemorrhage volume in patients who developed shunt-dependent hydrocephalus was significantly higher than that in patients who did not (mean difference 17.2 ml, p = 0.006). Larger hemorrhage volume and hemorrhage volume > 50 ml (OR 2.45, p = 0.03, 95% CI 1.08-5.54) were predictive of shunt-dependent hydrocephalus. Hemorrhage volume had adequate discrimination for the development of seizures (AUC 0.635) and shunted hydrocephalus (AUC 0.629).

CONCLUSIONS

Hemorrhage volume is an independent predictor of seizures and shunt-dependent hydrocephalus in patients with aSAH. Further evaluation of aSAH quantitative volumetric analysis may complement existing scales used in clinical practice and assist in patient prognostication and management.

Emerging Role of Microglia-Mediated Neuroinflammation in Epilepsy after Subarachnoid Hemorrhage

Epilepsy is a common and serious complication of subarachnoid hemorrhage (SAH), giving rise to increased morbidity and mortality. It's difficult to identify patients at high risk of epilepsy and the application of anti-epileptic drugs (AEDs) following SAH is a controversial topic. Therefore, it's pressingly needed to gain a better understanding of the risk factors, underlying mechanisms and the optimization of therapeutic strategies for epilepsy after SAH. Neuroinflammation, characterized by microglial activation and the release of inflammatory cytokines, has drawn growing attention due to its influence on patients with epilepsy after SAH. In this review, we discuss the risk factors for epilepsy after SAH and emphasize the critical role of microglia. Then we discuss how various molecules arising from pathophysiological changes after SAH activate specific receptors such as TLR4, NLRP3, RAGE, P2X7R and initiate the downstream inflammatory pathways. Additionally, we focus on the significant responses implicated in epilepsy including neuronal excitotoxicity, the disruption of blood-brain barrier (BBB) and the change of immune responses. As the application of AEDs for seizure prophylaxis after SAH remains controversial, the regulation of neuroinflammation targeting the key pathological molecules could be a promising therapeutic method. While neuroinflammation appears to contribute to epilepsy after SAH, more comprehensive experiments on their relationships are needed.

Neurovascular disease, diagnosis, and therapy: Subarachnoid hemorrhage and cerebral vasospasm

The worldwide incidence of spontaneous subarachnoid hemorrhage is about 6.1 per 100,000 cases per year (Etminan et al., 2019). Eighty-five percent of cases are due to intracranial aneurysms. The mean age of those affected is 55 years, and two-thirds of the patients are female. The prognosis is related mainly to the neurologic condition after the subarachnoid hemorrhage and the age of the patient. Overall, 15% of patients die before reaching the hospital, another 20% die within 30 days, and overall 75% are dead or remain disabled. Case fatality has declined by 17% over the last 3 decades. Despite the improvement in outcome probably due to improved diagnosis, early aneurysm repair, administration of nimodipine, and advanced intensive care support, the outcome is not very good. Even among survivors, 75% have permanent cognitive deficits, mood disorders, fatigue, inability to return to work, and executive dysfunction and are often unable to return to their premorbid level of functioning. The key diagnostic test is computed tomography, and the treatments that are most strongly supported by scientific evidence are to undertake aneurysm repair in a timely fashion by endovascular coiling rather than neurosurgical clipping when feasible and to administer enteral nimodipine. The most common complications are aneurysm rebleeding, hydrocephalus, delayed cerebral ischemia, and medical complications (fever, anemia, and hyperglycemia). Management also probably is optimized by neurologic intensive care units and multidisciplinary teams.

Perioperative Management of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is an acute neurologic emergency. Prompt definitive treatment of the aneurysm by craniotomy and clipping or endovascular intervention with coils and/or stents is needed to prevent rebleeding. Extracranial manifestations of aneurysmal subarachnoid hemorrhage include cardiac dysfunction, neurogenic pulmonary edema, fluid and electrolyte imbalances, and hyperglycemia. Data on the impact of anesthesia on long-term neurologic outcomes of aneurysmal subarachnoid hemorrhage do not exist. Perioperative management should therefore focus on optimizing systemic physiology, facilitating timely definitive treatment, and selecting an anesthetic technique based on patient characteristics, severity of aneurysmal subarachnoid hemorrhage, and the planned intervention and monitoring. Anesthesiologists should be familiar with evoked potential monitoring, electroencephalographic burst suppression, temporary clipping, management of external ventricular drains, adenosine-induced cardiac standstill, and rapid ventricular pacing to effectively care for these patients.

Lessons from the CONSCIOUS-1 Study

After years of research on treatment of aneurysmal subarachnoid hemorrhage (aSAH), including randomized clinical trials, few treatments have been shown to be efficacious. Nevertheless, reductions in morbidity and mortality have occurred over the last decades. Reasons for the improved outcomes remain unclear. One randomized clinical trial that has been examined in detail with these questions in mind is Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1). This was a phase-2 trial testing the effect of clazosentan on angiographic vasospasm (aVSP) in patients with aSAH. Clazosentan decreased moderate to severe aVSP. There was no statistically significant effect on the extended Glasgow outcome score (GOS), although the study was not powered for this endpoint. Data from the approximately 400 patients in the study were detailed, rigorously collected and documented and were generously made available to one investigator. Post-hoc analyses were conducted which have expanded our knowledge of the management of aSAH. We review those analyses here.

Lower Serum Iron and Hemoglobin Levels are Associated with Acute Seizures in Patients with Ruptured Cerebral Aneurysms

BACKGROUND AND OBJECTIVE

The aim of the study is to investigate the value of serum iron and hemoglobin levels for predicting acute seizures following aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Clinical and laboratorial data from patients with ruptured intracranial aneurysms were collected in the retrospective study. Age, sex, symptom onset, history of diabetes and hypertension, history of coronary artery disease, temperature, Hunt-Hess grade, Fisher grade, aneurysm location, hemoglobin, serum potassium, sodium, calcium, phosphorus, and iron were collected. Acute seizures were determined as seizures within 1 week following aSAH. Propensity score matching (PSM) analyses were performed to correct imbalances in patient characteristics between seizure and non-seizure groups.

RESULTS

A total of 760 patients were included. Incidence of acute seizures following aSAH was 6.4%. In the univariate analysis, significant differences were detected in age, admission Hunt-Hess grade, Fisher grade, hemoglobin, serum sodium, and serum iron between seizure and non-seizure groups. In multivariate logistic regression model, lower serum iron was considered as a risk factor for acute seizures (OR 0.182, 95% CI 0.084-0.393, p = 0.000), as well as lower hemoglobin (OR 0.977, 95% CI 0.962-0.993, p = 0.004) and higher serum sodium (OR 1.072, 95% CI 1.003-1.145, p = 0.039). After PSM, there were no significant differences in age, admission Hunt-Hess grade, Fisher grade, and serum sodium between seizure and non-seizure groups. The matched seizure group had lower serum iron and hemoglobin levels compared with the matched non-seizure group (p < 0.05). The optimal cutoff value for serum iron and hemoglobin levels as a predictor of acute seizure after aSAH was determined as 9.9 mmol/L (sensitivity was 81.63% and the specificity was 65.40%) and 119 g/L (sensitivity was 63.27% and the specificity was 70.18%), respectively.

CONCLUSIONS

Serum iron and hemoglobin levels were inversely associated with a high risk of acute seizures following aSAH.

Association between weekend admissions and mortality after aneurysmal subarachnoid hemorrhage: the "weekend effect" revisited

OBJECTIVE

Higher mortality has been reported with weekend or after-hours patient admission across a wide range of surgical and medical specialties, a phenomenon termed the "weekend effect." The authors evaluated whether weekend admission contributed to death and long-term neurological outcome in patients following aneurysmal subarachnoid hemorrhage.

METHODS

A post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) study was conducted. Univariable and stepwise multivariable logistic regression analyses were performed to assess the associations between weekend admission and mortality and long-term neurological outcome.

RESULTS

Of 413 subjects included in the CONSCIOUS-1 study, 140 patients had been admitted during the weekend. A significant interaction was identified between weekend admission and neurological grade on presentation, suggesting that the outcomes of patients who had initially presented with a poor grade were disproportionately influenced by the weekend admission. On stepwise multivariable logistic regression in the subgroup of patients who had presented with a poor neurological grade (29 of 100 patients), admission on the weekend was found to be independently associated with death (OR 6.59, 95% CI 1.62-26.88, p = 0.009). Weekend admission was not associated with long-term neurological outcome.

CONCLUSIONS

Weekend admission was an independent risk factor for death within 12 weeks following aneurysmal subarachnoid hemorrhage in patients presenting with a poor neurological grade. Further work is required to identify and mitigate any mediating factors.

Anemia After Aneurysmal Subarachnoid Hemorrhage Is Associated With Poor Outcome and Death

Background and Purpose- Anemia after aneurysmal subarachnoid hemorrhage is common and potentially modifiable. Here, we first evaluate the effect of anemia on neurological outcome and death and second, study the effects of packed red blood cell transfusion on outcome. Methods- A secondary analysis on 413 subjects in the CONSCIOUS-1 study (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage). Multivariable logistic regression identified independent risk factors for anemia and determined the effect of anemia on neurological outcome and death, while adjusting for selected covariates. Optimal predictive thresholds for hemoglobin levels were determined using receiver operating characteristic curve analysis. Finally, patients were pseudorandomized to transfusion using propensity score matching to study the effect of transfusions on outcome. Results- Anemia, defined as hemoglobin <10 g/dL, was present in 5% of patients at presentation, in 29% of patients after aneurysm securing (days 1-3), and in 32% of patients during the peak delayed cerebral ischemia risk period (days 5-9). Anemia after aneurysm securing (odds ratio, 1.96; 95% confidence interval, 1.07-3.59; P=0.03) and during the delayed cerebral ischemia window (odds ratio, 2.63; 95% confidence interval, 1.46-4.76; P=0.0014) was independently associated with poor neurological outcome. Anemia postaneurysm securing (odds ratio, 3.50; 95% confidence interval, 1.15-10.62; P=0.027) but not during the delayed cerebral ischemia window was associated with death. Using propensity score-matched cohorts, we found that transfusion of anemic patients did not improve long-term outcome (P=0.8) or mortality rates (P=0.9). Transfusion of patients with a hemoglobin concentration >10 g/dL was associated with improved neurological outcomes (odds ratio, 0.09; 95% confidence interval, 0.002-0.72; P=0.015), with no differences in mortality. Conclusions- Anemia after aneurysmal subarachnoid hemorrhage is associated with poor long-term neurological outcome and death. Transfusion of packed red blood cells is beneficial for patients who are not considerably anemic beforehand, suggesting further work needs to define the threshold but also the time period of anemia that is sufficient and necessary to contribute to poor outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00111085.

Use of Antiepileptic Drugs in Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION

Controversy exists in antiepileptic drug (AED) prophylaxis prescribing in patients with aneurysmal subarachnoid hemorrhage (SAH). We undertook the Use of Antiepileptic Drugs in Aneurysmal Subarachnoid Hemorrhage (ALIBI) study to identify factors associated with prescribing practices.

METHODS

A retrospective chart review of all consecutive patients requiring Level 1 care with aneurysmal SAH admitted between 2012 and 2014 to the intensive care unit at Toronto Western Hospital, Ontario, Canada, was conducted. Data were collected on clinical and imaging characteristics. Primary and secondary outcomes were AED prophylaxis and clinical seizure activity during hospitalization. Data were compared using chi-square or Mann-Whitney U-tests. Those variables found to be significant, or trending toward significance, on univariate analysis were fitted to multivariate regression.

RESULTS

Sixty-eight patients were included. Mean age was 62 ± 12.2, and 42.6% of patients were male. Of these, 21 patients (30.9%) received AED prophylactically, while 18 (26.5%) had reported seizures at some point during hospitalization. Female gender and presence of midline shift (MLS) were significantly associated or approached significance with AED prophylaxis in univariate analysis (p = 0.036 and p = 0.062, respectively). In multivariate analysis, only MLS was an independent predictor (odds ratio 5.09, p = 0.04).

CONCLUSION

The presence of MLS was an independent predictor of seizure activity in patients with aneurysmal SAH. AED prophylaxis prescribing patterns seemed arbitrary and was not informed by identifiable clinical factors or true risk factors for seizure. A current lack of evidence guiding AED prescribing practice highlights the need for larger studies in this patient population.

The Extracranial Consequences of Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is managed across the full spectrum of healthcare, from clinical diagnosis to management of the hemorrhage and associated complications. Knowledge of the pathogenesis and pathophysiology of SAH is widely known; however, a full understanding of the underlying molecular, cellular, and circulatory dynamics has still to be achieved. Intracranial complications including delayed ischemic neurologic deficit (vasospasm), rebleed, and hydrocephalus form the targets for initial management. However, the extracranial consequences including hypertension, hyponatremia, and cardiopulmonary abnormalities can frequently arise during the management phase and have shown to directly affect clinical outcome. This review will provide an update on the pathophysiology of SAH, including the intra- and extracranial consequences, with a particular focus on the extracranial consequences of SAH.

METHODS

We review the literature and provide a comprehensive update on the extracranial consequences of SAH that we hope will help the management of these cohort of patients.

RESULTS

In addition to the pathophysiology of SAH, the following complications were examined and discussed: vasospasm, seizures, rebleed, hydrocephalus, fever, anemia, hypertension, hypotension, hyperglycemia, hyponatremia, hypernatremia, cardiac abnormalities, pulmonary edema, venous thromboembolism, gastric ulceration, nosocomial infection, bloodstream infection/sepsis, and iatrogenic complications.

CONCLUSIONS

Although the intracranial complications of SAH can take priority in the initial management, the extracranial complications should be monitored for and recognized as early as possible because these complications can develop at varying times throughout the course of the condition. Therefore, a variety of investigations, as described by this article, should be undertaken on admission to maximize early recognition of any of the extracranial consequences. Furthermore, because the extracranial complications have a direct effect on clinical outcome and can lead to and exacerbate the intracranial complications, monitoring, recognizing, and managing these complications in parallel with the intracranial complications is important and would allow optimization of the patient's management and thus help improve their overall outcome.

Seizures and Choice of Antiepileptic Drugs Following Subarachnoid Hemorrhage: A Review

Seizures are important complications following a subarachnoid hemorrhage (SAH). The evidence for the use of antiepileptic drugs (AEDs) in treatment and prevention of those seizures is conflicting. The purpose of this review is to provide an up-to-date evidence summary of the incidence and outcomes of seizures following an SAH as well as the use of different AEDs post-SAH in order to evaluate the need for seizure prophylaxis, the choice of AEDs, and their dosing considerations in SAH patients. A literature search of PubMed, Medline, Embase, and the Cochrane Library was performed. A total of 37 studies were reviewed, mostly observational. Definitions of seizures in temporal relation to initial hemorrhage were variable. Similarly, the rates of seizures varied in the literature, ranging from 0 to 31%. Given the reported adverse outcomes associated with AED usage, seizure prophylaxis is not warranted. Levetiracetam appears to be better tolerated than phenytoin in SAH patients, though further research is needed. Higher initial dosing of levetiracetam might be required due to its enhanced clearance in SAH patients. In conclusion, there is a lack of quality evidence to definitively recommend the use of one AED over another. Further prospective research comparing the use of different AEDs in patients with an SAH is needed.

Neurosurgeon academic impact is associated with clinical outcomes after clipping of ruptured intracranial aneurysms

BACKGROUND

Surgeon-dependent factors such as experience and volume are associated with patient outcomes. However, it is unknown whether a surgeon's research productivity could be related to outcomes. The main aim of this study is to investigate the association between the surgeon's academic productivity and clinical outcomes following neurosurgical clipping of ruptured aneurysms.

METHODS

We performed a post-hoc analysis of 3567 patients who underwent clipping of ruptured intracranial aneurysms in the randomized trials of tirilazad mesylate from 1990 to 1997. These trials included 162 centers and 156 surgeons from 21 countries. Primary and secondary outcomes were: Glasgow outcome scale score and mortality, respectively. Total publications, H-index, and graduate degrees were used as academic indicators for each surgeon. The association between outcomes and academic factors were assessed using a hierarchical logistic regression analysis, adjusting for patient covariates.

RESULTS

Academic profiles were available for 147 surgeons, treating a total of 3307 patients. Most surgeons were from the USA (62, 42%), Canada (18, 12%), and Germany (15, 10%). On univariate analysis, the H-index correlated with better functional outcomes and lower mortality rates. In the multivariate model, patients under the care of surgeons with higher H-indices demonstrated improved neurological outcomes (p = 0.01) compared to surgeons with lower H-indices, without any significant difference in mortality. None of the other academic indicators were significantly associated with outcomes.

CONCLUSION

Although prognostication following surgery for ruptured intracranial aneurysms primarily depends on clinical and radiological factors, the academic impact of the operating neurosurgeon may explain some heterogeneity in surgical outcomes.

Seizures and Epileptiform Patterns in SAH and Their Relation to Outcomes

In subarachnoid hemorrhage (SAH), seizures are frequent and occur at different time points, likely reflecting heterogeneous pathophysiology. Young patients, those with more severe SAH (by clot burden or presence of severe mental status changes at onset or focal neurologic deficits at any time), those with associated increased cortical irritation (by infarction or presence of underlying hematoma), and patients undergoing craniotomy are at higher risk. Advanced neurophysiologic monitoring allows for seizure burden quantification, identification of subclinical seizures, and interictal patterns as well as neurovascular complications that may have an independent impact on the outcome in this population. Practice regarding seizure prophylaxis varies widely; its institution is often guided by the risk-benefit ratio of seizures and medication side effects. Newer anticonvulsants seem to be equally effective and may have a more favorable profile. However, questions regarding the association of seizures and vasospasm, the therapeutic dosing, timing, and duration of antiepileptic treatment and the impact of seizures and antiepileptics on the outcome remain unanswered. In this review, we provide a broad overview of the work in this area and offer a diagnostic and therapeutic approach based on our own expert opinion.

Spontaneous subarachnoid haemorrhage

Subarachnoid haemorrhage is an uncommon and severe subtype of stroke affecting patients at a mean age of 55 years, leading to loss of many years of productive life. The rupture of an intracranial aneurysm is the underlining cause in 85% of cases. Survival from aneurysmal subarachnoid haemorrhage has increased by 17% in the past few decades, probably because of better diagnosis, early aneurysm repair, prescription of nimodipine, and advanced intensive care support. Nevertheless, survivors commonly have cognitive impairments, which in turn affect patients' daily functionality, working capacity, and quality of life. Additionally, those deficits are frequently accompanied by mood disorders, fatigue, and sleep disturbances. Management requires specialised neurological intensive care units and multidisciplinary clinical expertise, which is better provided in high-volume centres. Many clinical trials have been done, but only two interventions are shown to improve outcome. Challenges that remain relate to prevention of subarachnoid haemorrhage by improved screening and development of lower-risk methods to repair or stabilise aneurysms that have not yet ruptured. Multicentre cooperative efforts might increase the knowledge that can be gained from clinical trials, which is often limited by small studies with differing criteria and endpoints that are done in single centres. Outcome assessments that incorporate finer assessment of neurocognitive function and validated surrogate imaging or biomarkers for outcome could also help to advance the specialty.

Dissociation of Early and Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Background and Purpose—

Cerebral infarction after aneurysmal subarachnoid hemorrhage is a significant cause of substantial morbidity and mortality. Because early and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage may be mediated by different processes, we evaluated whether aneurysm-securing methods contributed to infarcts and whether long-term outcomes differ between early and delayed infarcts.

Methods—

A post hoc analysis of the CONSCIOUS-1 study (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage) was performed. Using multivariate logistic regression analysis and propensity matching, independent clinical risk factors associated with infarctions were identified, and the contribution of cerebral infarcts to long-term outcomes was evaluated.

Results—

Within the cohort of 413 subjects, early infarcts were present in 76 subjects (18%), whereas delayed infarcts occurred in 79 subjects (19%), and 36 subjects (9%) had new infarctions that were present on both early and delayed imaging. Propensity score matching revealed a significantly higher proportion of early infarcts after clipping (odds ratio, 4.62; 95% confidence interval, 1.99–11.57; P =0.00012). Multivariate logistic regressions identified clipping as an independent risk factor for early cerebral infarction (odds ratio, 0.26; 95% confidence interval, 0.15–0.48; P <0.001), and angiographic vasospasm was an independent risk factor for delayed cerebral infarction (odds ratio, 1.79; 95% confidence interval, 1.03–3.13; P =0.039). Early infarcts were a significant independent risk factor for poor long-term outcomes at 3 months (odds ratio, 2.34; 95% confidence interval, 1.18–4.67; P =0.015).

Conclusions—

Clipping is an independent risk factor for the development of early cerebral infarcts, whereas delayed cerebral infarcts are associated with angiographic vasospasm. Early cerebral infarcts are stronger predictors of worse outcome than delayed infarction.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00111085.

Operative complications and differences in outcome after clipping and coiling of ruptured intracranial aneurysms

OBJECT

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with substantial morbidity and mortality, with better outcomes reported following endovascular coiling compared with neurosurgical clipping of the aneurysm. The authors evaluated the contribution of perioperative complications and neurological decline to patient outcomes after both aneurysm-securing procedures.

METHODS

A post hoc analysis of perioperative complications from the Clazosentan to Overcome Neurological iSChemia and Infarction Occurring after Subarachnoid hemorrhage (CONSCIOUS-1) study was performed. Glasgow Coma Scale (GCS) scores for patients who underwent neurosurgical clipping and endovascular coiling were analyzed preoperatively and each day following the procedure. Complications associated with a decline in postoperative GCS scores were identified for both cohorts. Because patients were not randomized to the aneurysm-securing procedures, propensity-score matching was performed to balance selected covariates between the 2 cohorts. Using a multivariate logistic regression, the authors evaluated whether a perioperative decline in GCS scores was associated with long-term outcomes on the extended Glasgow Outcome Scale (eGOS).

RESULTS

Among all enrolled subjects, as well as the propensity-matched cohort, patients who underwent clipping had a significantly greater decline in their GCS scores postoperatively than patients who underwent coiling (p = 0.0024). Multivariate analysis revealed that intraoperative hypertension (p = 0.011) and intraoperative induction of hypotension (p = 0.0044) were associated with a decline in GCS scores for patients undergoing clipping. Perioperative thromboembolism was associated with postoperative GCS decline for patients undergoing coiling (p = 0.03). On multivariate logistic regression, postoperative neurological deterioration was strongly associated with a poor eGOS score at 3 months (OR 0.86, 95% CI 0.78-0.95, p = 0.0032).

CONCLUSIONS

Neurosurgical clipping following aSAH is associated with a greater perioperative decline in GCS scores than endovascular coiling, which is in turn associated with poorer long-term outcomes. These findings provide novel insight into putative mechanisms of improved outcomes following coiling, highlighting the potential importance of perioperative factors when comparing outcomes between clipping and coiling and the need to mitigate the morbidity of surgical strategies following aSAH.

Cocaine use as an independent predictor of seizures after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Seizures are relatively common after aneurysmal subarachnoid hemorrhage (aSAH). Seizure prophylaxis is controversial and is often based on risk stratification; middle cerebral artery (MCA) aneurysms, associated intracerebral hemorrhage (ICH), poor neurological grade, increased clot thickness, and cerebral infarction are considered highest risk for seizures. The purpose of this study was to evaluate the impact of recent cocaine use on seizure incidence following aSAH.

METHODS

Prospectively collected data from aSAH patients admitted to 2 institutional neuroscience critical care units between 1991 and 2009 were reviewed. The authors analyzed factors that potentially affected the incidence of seizures, including patient demographic characteristics, poor clinical grade (Hunt and Hess Grade IV or V), medical comorbidities, associated ICH, intraventricular hemorrhage (IVH), hydrocephalus, aneurysm location, surgical clipping and cocaine use. They further studied the impact of these factors on "early" and "late" seizures (defined, respectively, as occurring before and after clipping/coiling).

RESULTS

Of 1134 aSAH patients studied, 182 (16%) had seizures; 81 patients (7.1%) had early and 127 (11.2%) late seizures, with 26 having both. The seizure rate was significantly higher in cocaine users (37 [26%] of 142 patients) than in non-cocaine users (151 [15.2%] of 992 patients, p = 0.001). Eighteen cocaine-positive patients (12.7%) had early seizures compared with 6.6% of cocaine-negative patients (p = 0.003); 27 cocaine users (19%) had late seizures compared with 10.5% non-cocaine users (p = 0.001). Factors that showed a significant association with increased risk for seizure (early or late) on univariate analysis included younger age (< 40 years) (p = 0.009), poor clinical grade (p = 0.029), associated ICH (p = 0.007), and MCA aneurysm location (p < 0.001); surgical clipping was associated with late seizures (p = 0.004). Following multivariate analysis, age < 40 years (OR 2.04, 95% CI 1.355-3.058, p = 0.001), poor clinical grade (OR 1.62, 95% CI 1.124-2.336, p = 0.01), ICH (OR 1.95, 95% CI 1.164-3.273, p = 0.011), MCA aneurysm location (OR 3.3, 95% CI 2.237-4.854, p < 0.001), and cocaine use (OR 2.06, 95% CI 1.330-3.175, p = 0.001) independently predicted seizures.

CONCLUSIONS

Cocaine use confers a higher seizure risk following aSAH and should be considered during risk stratification for seizure prophylaxis and close neuromonitoring.

National socioeconomic indicators are associated with outcomes after aneurysmal subarachnoid hemorrhage: a hierarchical mixed-effects analysis

OBJECT

Although heterogeneity exists in patient outcomes following subarachnoid hemorrhage (SAH) across different centers and countries, it is unclear which factors contribute to such disparities. In this study, the authors performed a post hoc analysis of a large international database to evaluate the association between a country's socioeconomic indicators and patient outcome following aneurysmal SAH.

METHODS

An analysis was performed on a database of 3552 patients enrolled in studies of tirilazad mesylate for aneurysmal SAH from 1991 to 1997, which included 162 neurosurgical centers in North and Central America, Australia, Europe, and Africa. Two primary outcomes were assessed at 3 months after SAH: mortality and Glasgow Outcome Scale (GOS) score. The association between these outcomes, nation-level socioeconomic indicators (percapita gross domestic product [GDP], population-to-neurosurgeon ratio, and health care funding model), and patientlevel covariates were assessed using a hierarchical mixed-effects logistic regression analysis.

RESULTS

Multiple previously identified patient-level covariates were significantly associated with increased mortality and worse neurological outcome, including age, intraventricular hemorrhage, and initial neurological grade. Among national-level covariates, higher per-capita GDP (p < 0.05) was associated with both reduced mortality and improved neurological outcome. A higher population-to-neurosurgeon ratio (p < 0.01), as well as fewer neurosurgical centers per population (p < 0.001), was also associated with better neurological outcome (p < 0.01). Health care funding model was not a significant predictor of either primary outcome.

CONCLUSIONS

Higher per-capita gross GDP and population-to-neurosurgeon ratio were associated with improved outcome after aneurysmal SAH. The former result may speak to the availability of resources, while the latter may be a reflection of better outcomes with centralized care. Although patient clinical and radiographic phenotypes remain the primary predictors of outcome, this study shows that national socioeconomic disparities also explain heterogeneity in outcomes following SAH.

Controversies and evolving new mechanisms in subarachnoid hemorrhage

Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.