Impact of Ruptured Aneurysm Circulation on Mortality: A Nationwide Inpatient Sample Analysis

ObjectiveThis study investigates the effect of aneurysm circulation on mortality and patient outcomes after aneurysmal subarachnoid hemorrhage (SAH) within the United States.MethodsA retrospective cohort study was conducted using the Nationwide Inpatient Sample (NIS), a part of the Healthcare Cost and Utilization Project (HCUP), with ICD-10 codes for non-traumatic SAH between 2015-2016. Aneurysms were stratified as either anterior or posterior circulation. Multivariate logistic regression was used to find the impact of selected variables on the odds of mortality.ResultsThe NIS reported 1,892 cases of non-traumatic SAH within the study period that were predominantly anterior circulation (82.6%), female (68.6%), white (57.7%), with mean age of 59.07 years, and in-hospital mortality of 21.4%. Anterior circulation aneurysms were associated with lower severity of initial illness (p = 0.014) but higher likelihood of vasospasm (p = 0.0006) than those of the posterior circulation. In a multivariate logistic regression analysis, mortality was associated with posterior circulation aneurysms (OR: 1.42; CI 95% 1.005-20.10, p = 0.047), increasing age (OR: 1.035; 95% CI 1.022-1.049; p < 0.0001), and shorter hospital stays (OR: 0.7838; 95% CI 0.758-0.811; p < 0.0001). Smoking history (OR: 0.825; 95% CI 0.573-1.187, p > 0.05) and vasospasm (OR: 1.005; 95% CI 0.648-1.558; p > 0.05) were not significantly associated with higher odds of mortality.ConclusionsMortality following aneurysmal SAH is associated with posterior circulation aneurysms, and increasing age, but not smoking history or vasospasm. These findings may be useful for prognostication and counseling patients and families.     

颅内动脉瘤破裂风险和动脉瘤形态学参数的关系

目的 探讨颅内动脉瘤破裂风险相关的动脉瘤形态学参数。方法 回顾性分析114例颅内动脉瘤（61例未破裂动脉瘤,53例破裂动脉瘤）的临床资料,采用多因素Logistic回归分析检验7个动脉瘤形态学参数[动脉瘤直径、动脉瘤高度与瘤颈宽度比值、动脉瘤高度与载瘤动脉直径比值（SR）、长宽比、入射角度、载瘤动脉角度和颈体角度）与动脉瘤破裂风险的关系。结果 动脉瘤长度越长,破裂风险越小（OR=0.470;95% CI 0.286~0.771;P=0.003）;SR越大,破裂风险越大（OR=18.998;95% CI 2.851~126.607;P=0.002）;颈体角度越大,破裂风险越大（OR=1.073;95% CI 1.023~1.125;P=0.004）。结论 SR、动脉瘤长度和颈体角度是判断颅内动脉瘤破裂风险的重要指标。     

Risk factors for multiple intracranial aneurysms

BACKGROUND AND PURPOSE: The presence of multiple intracranial aneurysms may be a sign of significant risk factors for aneurysm formation that differ from those factors that increase risk for aneurysm rupture. Only 2 studies concern independent risk factors for multiple aneurysms, and the results are in part controversial. This study was designed to identify independent risk factors for multiple intracranial aneurysms in patients with subarachnoid hemorrhage. METHODS: Of 266 patients with aneurysmal subarachnoid hemorrhage (139 men and 127 women, aged 15 to 60 years), 80 (30%) had multiple intracranial aneurysms. The prevalence of several health-related habits, previous diseases, and medications of these patients were compared by multiple logistic regression between those with single and those with multiple aneurysms. RESULTS: On the basis of multivariate statistics, only regular cigarette smoking at any time was a significant risk factor for the presence of multiple aneurysms. The odds ratio (OR) of smoking for multiple aneurysms was 2.10 (95% CI, 1.06 to 4.13) after adjustment for age and sex. After additional adjustment for hypertension, the risk was 2.06 (95% CI, 1. 04 to 4.07). Of other variables, only age (OR, 1.02 per year; 95% CI, 1.00 to 1.05; P=0.09) and female sex (OR, 1.60; 95% CI, 0.90 to 2. 85; P=0.11) showed a tendency to increase the risk for multiple aneurysms after adjustment for smoking. On the other hand, patients with hypertension had significantly (P=0.029) more aneurysms (1. 61+/-1.04) than did those without (1.37+/-0.68), although they did not more frequently have multiple aneurysms. CONCLUSIONS: Cigarette smoking and possibly also age and female sex seem to be risk factors for multiple intracranial aneurysms in patients of working age who have suffered a subarachnoid hemorrhage. Patients with hypertension seem to have more aneurysms than those without.     

Aneurysmal and clinical characteristics as risk factors for intracerebral haematoma from aneurysmal rupture

Intracerebral haematoma (ICH) occurs in one-third of patients with aneurysmal subarachnoid haemorrhage (SAH) and is associated with poor prognosis. Identification of risk factors for ICH from aneurysmal rupture may help in balancing risks of treatment of unruptured aneurysms. We assessed potential clinical and aneurysmal risk factors for ICH from aneurysmal rupture. In all 310 SAH patients admitted to our service between 2005 and 2007, we compared clinical risk factors (gender, age, smoking, hypertension, history of SAH and family history) of patients with and without an ICH. From the latest admitted, 50 patients with and 50 without ICH, we compared the location, shape and direction of blood flow of the aneurysms on CT-angiography. Relative risks (RRs) of ICH were 1.2 (95% confidence interval, CI):0.7–1.8) for males, 1.0 (95%CI:0.7–1.4) for age ≥55 year, 1.0 (95%CI:0.6–1.6) for smoking, 0.9 (95%CI:0.5–1.5) for hypertension, 0.6 (95%CI:0.1–3.8) for history of SAH and 0.5 (95%CI:0.2–1.3) for family history of SAH. RRs of ICH were 1.8 (95%CI:1.2–2.5) for MCA aneurysms, 0.5 (95%CI:0.3–1.0) for ICA aneurysms, 0.4 (95%CI:0.1–1.3) for posterior circulation aneurysms, and 0.7 (95%CI:0.3–1.3) for multilobed aneurysms. The RRs of other aneurysmal characteristics varied between 0.9 and 1.2. Patients with MCA aneurysms are at a higher risk of developing ICH. The other aneurysmal or clinical factors have no or only minor influence on the risk of ICH after rupture and are, therefore, not helpful in deciding on treatment of unruptured aneurysms.     

Relation between age and number of aneurysms in patients with subarachnoid haemorrhage

BACKGROUND: Because age and the presence of atherosclerosis are risk factors for the presence of aneurysms, the presence of multiple aneurysms may also increase with age. Familial preponderance is another risk factor for the presence of aneurysms. Familial subarachnoid haemorrhage (SAH) occurs at an earlier age than sporadic SAH, and a higher frequency of multiple aneurysms has been suggested in familial SAH. This may imply that the multiplicity of aneurysms is associated with younger age. We studied the relation between age and the number of aneurysms in patients with SAH. METHODS: From our database we selected patients with aneurysmal SAH admitted between 1985 and 1999. Inclusion criteria were: (1) both carotid and vertebral arteries had been visualised; (2) at least one aneurysm was found, and (3) admission within 72 h after onset of symptoms. For the 555 patients included we recorded the age, sex and number of aneurysms. The patients were categorised into patients with a single aneurysm, patients with more than one aneurysm and those with more than two aneurysms. For all categories we calculated the proportion of patients younger than the median age and the differences between these proportions, with corresponding 95% confidence intervals (CI). We also calculated relative risks (RR) of multiple aneurysms for gender and age below the median. RESULTS: 485 patients had a single aneurysm, and 70 patients had more than one aneurysm. The proportion of patients younger than the median age (51 years) with one aneurysm was 47.8%, for more than one aneurysm 61.4% (difference 13.6%; 95% CI 1.4-25.8), and for more than two aneurysms 82.6% (difference 34.8%, 95% CI 18.7-50.9). The RR of women for multiple aneurysms was 1.52 (95% CI 0.61-3.77), and that of age below the median 4.86 (95% CI 1.68-14.1). CONCLUSIONS: Patients with multiple aneurysms are younger than patients with a single aneurysm. This may suggest that atherosclerotic risk factors are less important than genetic factors in the development of multiple aneurysms.     

破裂性颅内动脉瘤介入术中再破裂的危险因素分析及应急处理

目的 探讨破裂性颅内动脉瘤介入术中再破裂的危险因素、应急处理办法及疗效.方法分析自2005年至2009年广东医学院附属医院神经外科收治的236例行介入治疗的破裂性颅内动脉瘤患者的临床资料,应用非条件logistic逐步回归方法分析其介入术中再破裂的危险因素,并总结其中发生再破裂的16例患者(6.78%)的处理措施及疗效. 结果 破裂性颅内动脉瘤介入术中再破裂的危险因素为:微小动脉瘤(OR=6.353,95%CI:1.26～31.894,P=0.025),A1、M1远端动脉瘤(OR=35.449,95%CI:3.053～411.642,P=0.004),动脉粥样硬化(OR=5.961,95%CI:1.215～29.260,P=0.028),轻度脑血管痉挛(OR=13.048,95%CI:1.220～139.574,P=0.034),重度脑血管痉挛(OR=14.826,95%CI:1.871～117.488,P=0.011).16例患者均采用鱼精蛋白快速中和肝素及迅速完成动脉瘤的栓塞,其中12例Hunt-HessⅢ级以上者予急诊行脑室外引流术,结果6例死亡,1例植物生存状态,9例恢复良好. 结论 动脉硬化,脑血管痉挛,微小动脉瘤,A1、M1远端动脉瘤等因素容易导致破裂性颅内动脉瘤介入术中再破裂.快速中和肝素及迅速完成动脉瘤的栓塞,对重症患者行急诊脑室外引流术是应对介入术中动脉瘤再破裂的关键,有利于病死率降低,预后改善.

Abstract：

Objective To study the risk factors of intraprocedural re-rupture (IPR) of ruptured intracranial aneurysms, and the emergency management on this event and its efficacy. Methods The clinical data of 236 patients with ruptured intracranial aneurysms, admitted to our hospital from 2005 to 2009 and treated with embolization, were retrospectively analyzed; non-conditional logistic regression analysis was performed to analyze the risk factors of IPR of ruptured intracranial aneurysms. And the emergency management of IPR and its efficacy were concluded in 16 patients with IPR. Results The risk factors of IPR of ruptured intracranial aneurysms included small aneurysms with a diameter smaller than or equaling to 3.0 mm (OR=6.353, 95% CI: 1.266-31.894, P=0.025), aneurysms at distal part of Al and M1 segment of the anterior cerebral artery or middle cerebral artery (OR=35.449, 95% CI:3.053-411.642, P=0.004), atherosclerosis (OR=5.961, 95% CI: 1.215-29.260, P=0.028), mild vasospasm (OR=13.048, 95% CI: 1.220-139.574, P=0.034) and severe vasospasm (OR=14.826, 95% CI:1.871-117.488, P=0.011). Immediate reversal of heparin anticoagulation with protamine sulfate and rapid completion of coiling were performed in 16 patients (6.78%) occurred IPR. Emergent external ventricular drainage was performed in 12 patients having above Hunt-Hess grade Ⅲ:6 patients died; 1 was under persistent vegetative state and 9 fully recovered. Conclusion Small aneurysms, atherosclerosis,cerebral vasospasm and aneurysms at the distal part of Al or M1 segment may easily lead to IPR of ruptured intracranial aneurysms. Rapid completion of coiling combined with immediate reversal of heparin anticoagulation, and emergent external ventricular drainage performed in severe patients are confirmed to be the keys, which can decrease the death rate and improve the prognosis.     

Risk factors for aneurysmal subarachnoid haemorrhage: the Tromsø study

Methods: The Tromsø health study is a population based survey of risk factors for cardiovascular disease in 27 161 subjects. 26 cases of aneurysmal SAH were identified in which risk factors were registered before the bleeding. Four age and sex matched controls were selected for each case. A backward logistic regression analysis was conducted and odds ratios (ORs) for significant risk factors were calculated. Systolic and diastolic blood pressure, cigarette smoking habits, serum concentrations of lipoproteins, body mass index, and coffee consumption were analysed. Results: The crude annual incidence rate of aneurysmal SAH was 8.84/100 000 population. The proportion of current smokers was significantly (p = 0.003) higher in patients with SAH (73.1%) than in controls (41.3%). Drinking more than five cups of coffee per day was more common among patients (85%) than controls (59%) (p = 0.004). Mean (SD) systolic blood pressure was higher (p = 0.017) in patients (154.0 (32.5)) than in controls (136.3 (23.3)). Regression analysis showed that cigarette smoking (p = 0.04), systolic blood pressure (p < 0.0001), and coffee consumption (p = 0.004) were independent risk factors for SAH. The OR of current smokers versus never smokers was 4.55 (95% confidence interval (CI) 1.08 to 19.30) and the OR of drinking more than five cups of coffee a day was 3.86 (95% CI 1.01 to 14.73). The OR of an increase in systolic blood pressure of 20 mm Hg was 2.46 (95% CI 1.52 to 3.97). Conclusions: Cigarette smoking and hypertension are significant independent risk factors for aneurysmal SAH. A high coffee consumption may also predispose patients to aneurysmal SAH.     

血管内治疗颅内动脉瘤术后发生急性脑积水的危险因素及处理

目的 可能危险因素进行Logistic多元回归分析.结果 Hunt-Hess分级和早期腰池持续置管引流为颅内动脉瘤血管内介入治疗后并发急性脑积水的最重要影响因素.结论 颅内动脉瘤血管内介入治疗后早期选择腰大池蛛网膜下腔持续引流,可预防急性脑积水发生,该方法可避免脑室穿刺,起到治疗急性脑积水的作用.     

动脉瘤性蛛网膜下腔出血后脑血管痉挛的脑血流动力学改变

目的探讨动脉瘤性蛛网膜下腔出血（aSAH）后脑血管痉挛（CVS）的血流动力学改变。方法对337例（382枚动脉瘤）aSAH患者临床资料进行回顾性分析,均经数字减影血管造影（DSA）和／或CT血管造影（CTA）检查证实为动脉瘤（An）,其中动脉瘤颈夹闭术297例,瘤颈夹闭及载瘤动脉塑形术29例,动脉瘤孤立术8例及包裹术3例。术后给予尼莫地平持续泵入扩血管、脑脊液引流、3H疗法等治疗,并于SAH1—3d．4～7d,8～14d、15～20d进行床边经颅超声多普勒（TCD）检测,主要观察MCA平均血流速度（VmMcA）、计算Lindegaard指数,即同侧MCA与颅外段ICAVm之比（LI）,观察CVS及颅内压（ICP）等脑血流动力学变化。结果SAH患者不同程度的存在CVS,25％的患者1—3d就出现CVS,8～14d达高峰;Hunt-Hess分级与CVS的变化成正相关;102例患者（102／337,30．3％）出现不同程度的颅内压增高;17例（17／337,5％）出现延迟性缺血性神经功能障碍（DIND）,颅内压增高且有CVS者预后较差。结论TCD可以床边、动态监测aSAH患者的脑血流动力学改变,具有无创、简单易行的特点。TCD检测的脑血流速度、Lindegaard指数和频谱形态相结合对临床和血管造影诊断CVS有价值。     

High-Dose Simvastatin Is Effective in Preventing Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study in Korean Patients

ObjectiveThe goal of this study was to assess the effect of high-dose simvastatin on cerebral vasospasm and its clinical outcome after aneurysmal subarachnoid hemorrhage (SAH) in Korean patients.MethodsThis study was designed as a prospective observational cohort study. Its subjects were aneurysmal SAH patients who had undergone aneurysm clipping or coiling. They were assigned to 1 of 3 groups : the 20 mg, 40 mg, and 80 mg simvastatin groups. The primary end-point was the occurrence of symptomatic vasospasm. The clinical outcome was assessed with the modified Rankin Scale (mRS) score after 1 month and 3 months. The risk factors of the development of vasospasm were assessed by logistic regression analysis.ResultsNinety nine patients with aneurysmal SAH were treated and screened. They were sequentially assigned to the 20 mg (n=22), 40 mg (n=34), and 80 mg (n=31) simvastatin groups. Symptomatic vasospasm occurred in 36.4% of the 20 mg group, 8.8% of the 40 mg group, and 3.2% of the 80 mg group (p=0.003). The multiple logistic regression analysis showed that poor Hunt-Hess grades (OR=5.4 and 95% CI=1.09-26.62) and high-dose (80 mg) simvastatin (OR=0.09 and 95% CI=0.1-0.85) were independent factors of symptomatic vasospasm. The clinical outcomes did not show a significant difference among the three groups.ConclusionThis study demonstrated that 80 mg simvastatin treatment was effective in preventing cerebral vasospasm after aneurysmal SAH, but did not improve the clinical outcome in Korean patients.     

Aneurysms in relatives of patients with subarachnoid hemorrhage: frequency and risk factors. MARS Study Group. Magnetic Resonance Angiography in Relatives of patients with Subarachnoid hemorrhage.

OBJECTIVE: To evaluate the frequency and identify risk factors of unruptured aneurysms in first-degree relatives of patients with sporadic subarachnoid hemorrhage (SAH). BACKGROUND: First-degree relatives (parents, siblings, and children) of patients with SAH have a three to seven times increased risk of SAH. METHODS: Magnetic resonance angiography (MRA) was performed in 626 first-degree relatives of a consecutive series of 193 index patients with "sporadic" SAH (participation rate, 78% of eligible relatives). The authors recorded demographic and medical data, and performed blood pressure measurements and blood tests (cholesterol, high-density lipid cholesterol, triglycerides, apoprotein A1, lipoprotein a, glucose). RESULTS: Aneurysms were found in 25 of 626 relatives (4.0%; 95% CI, 2.6 to 5.8%), and 6 relatives had multiple aneurysms. Index patients with multiple aneurysms and a younger age had a higher risk of aneurysms in relatives. Siblings of index patients had a four times higher risk than children. In screened relatives female sex, increasing age, polycystic kidney disease, hypertension, and elevated levels of cholesterol and glucose tended to be associated with a higher risk of aneurysms. No increase in risk was conferred by smoking or alcohol use, or by a previous family history of SAH or of atherosclerosis. CONCLUSIONS: First-degree relatives of index patients with sporadic subarachnoid hemorrhage have a 4.0% chance of intracranial aneurysms. Being a sibling of the index patient is the most important risk factor. Risk factors for general atherosclerosis (hypertension, smoking, hypercholesterolemia, high levels of blood triglycerides, lipoprotein a, and apoprotein A1) and use of alcohol do not increase the risk of intracranial aneurysms significantly in these relatives.     

Impact of early surgery after aneurysmal subarachnoid haemorrhage

Objectives – To investigate the effect of early aneurysm surgery (<72 h) on outcome in patients with subarachnoid haemorrhage (SAH). Materials and methods – We studied two consecutive series of patients with aneurysmal SAH [postponed surgery (PS) cohort, n = 118, 1989–1992: surgery was planned on day 12 and early surgery (ES) cohort, n = 85, 1996–1998: ES was performed only in patients with Glasgow Coma Scale (GCS) >13]. We used multivariable logistic regression analysis to assess outcome at 3 months. Results – Favourable outcome (Glasgow Outcome Scale 4 or 5) was similar in both cohorts. Cerebral ischemia occurred significantly more often in the ES cohort. The occurrence of rebleeds was similar in both cohorts. External cerebrospinal fluid (CSF) drainage was performed more often in the ES cohort (51% vs 19%). Patients with cisternal sum score (CSS) of subarachnoid blood <15 on admission [adjusted odds ratio (OR) for favourable outcome: 6.4, 95% confidence interval (CI) 1.0–39.8] and patients with both CSS <15 and GCS > 12 on admission benefited from the strategy including ES (OR 10.5, 95% CI 1.1–99.4). Conclusions – Our results support the widely adopted practice of ES in good‐grade SAH patients.     

Risk factors for re-bleeding of aneurysmal subarachnoid hemorrhage: Meta-analysis of observational studies

ObjectiveThe mortality of re-bleeding following aneurysmal subarachnoid hemorrhage is high, and surviving patients often have poor clinical condition and worse outcome than patients with a single bleed. In this study, we performed an updated systematic review and meta-analysis to determine the most common risk factors for re-bleeding in this patient population, with the goal of providing neurologists, neurosurgeons, neuro-interventionalists with a simple and fast method to evaluate the re-bleeding risk for aneurysmal subarachnoid hemorrhage.MethodWe conducted a thorough meta-analysis of the risk factors associated with re-bleeding or re-rupture of intracranial aneurysms in cases published between 2000 and 2013. Pooled mean difference was calculated for the continuous variables (age), and pooled odds ratio (OR) was calculated for categorical factors. If heterogeneity was significant (p < 0.05), a random effect model was applied; otherwise, a fixed model was used. Testing for pooled effects and statistical significance for each potential risk factor were analyzed using Review Manager software.ResultsOur literature search identified 174 articles. Of these, only seven retrospective studies met the inclusion criteria. These seven studies consisted of 2470 patients, 283 of which had aneurysmal re-bleeding, resulting in a weighted average rate of re-bleeding of 11.3% with 95% confidence interval [CI]: 10.1–12.6. In this population, sex (OR 1.46; 95% CI: 1.11–1.92), high systolic blood pressure [SBP] (OR 2.52; 95% CI: 1.40–4.53), aneurysm size (OR 3.00; 95% CI: 2.06–4.37), clinical condition (Hunt & Hess) (OR 4.94; 95% CI: 2.29,10.68), and Fisher grade (OR 2.29; 95% CI: 1.45, 3.61) were statistically significant risk factors for re-bleeding.ConclusionSex, high SBP, high Fisher grade, aneurysm size larger than 10 mm, and poor clinical condition were independent risk factors for aneurysmal re-bleeding. The importance of early aneurysm intervention and careful consideration of patient risk factors should be emphasized to eliminate the risk of re-bleeding and poor outcome.     

A single centre study of coil embolization of intracranial aneurysms comparing bare platinum and PGLA-coated coils

There is no robust consensus on the efficacy of polyglycolic/polylactic acid (PGLA)-coated coils used in the endovascular embolization of intracranial aneurysms. We present a comparative study of bare platinum coils and PGLA-coated Gugliemi Detachable Coils (GDC) in the treatment of intracranial aneurysms at a single centre, using target aneurysm recurrence and angiographic recanalization as the primary endpoints. We included all patients treated between 1998 and 2009 who had undergone at least one angiographic post-procedural follow-up. Patient demographics, clinical presentation, operative notes, and all relevant imaging were collected. Of the 441 aneurysms with follow-up, 290 were treated with at least one PGLA coil and 151 aneurysms were treated exclusively with bare platinum coils. At follow-up, 26.5% of platinum controls demonstrated angiographic recanalization, compared to 31.4% of PGLA-treated aneurysms (p=0.002). PGLA-treated aneurysms were more likely to have an angiographic remnant at follow-up (odds ratio [OR]=1.96, 95% confidence interval [CI]=1.26-3.04, p=0.003). The post-operative Raymond score was the only predictor of retreatment (OR=1.6, 95% CI=1.08-2.24, p=0.020), and was the second strongest predictor of a complete angiographic result at follow-up (OR=1.67, 95% CI=1.22-2.27, p=0.001). We concluded that PGLA-coated coils demonstrated poorer post-operative and long-term angiographic occlusion in the treatment of intracranial aneurysms, compared to bare platinum coils.     

Initial intracranial pressure is an independent predictor of unfavorable functional outcomes after aneurysmal subarachnoid hemorrhage

The authors sought to evaluate whether initial intracranial pressure was associated with functional outcomes following aneurysmal subarachnoid hemorrhage. This retrospective analysis consisted of 54 consecutive patients with aneurysmal subarachnoid hemorrhage and acute symptomatic hydrocephalus requiring emergent placement of an external ventricular drain. Patient demographics, clinical data, intracranial pressure parameters, and radiographic imaging were collected. Functional outcomes were evaluated at 3 months using the modified Rankin Scale and dichotomized as favorable (modified Rankin Scale 0–2) or unfavorable (modified Rankin Scale 3–6). Univariate and multivariate logistic regression analyses were performed to investigate parameters independently associated with functional outcomes. In an adjusted multivariate logistic regression model, initial intracranial pressure (OR: 1.371, 95% CI: 1.119–1.679; p = 0.002) was found to be an independent predictor of unfavorable functional outcomes at 3 months. Receiver operating characteristic curve analysis for the prediction of unfavorable functional outcomes demonstrated that initial intracranial pressure exhibited an acceptable area under the curve (AUC = 0.901, 95% CI: 0.818–0.985; p < 0.001). The optimal predictive threshold to distinguish between favorable and unfavorable functional outcomes was identified at an initial intracranial pressure of 25 mmHg.     

Trigger factors for rupture of intracranial aneurysms in relation to patient and aneurysm characteristics

Female gender, age above 60 years, and an aneurysm larger than 5 mm or location on the posterior circulation are associated with a higher rupture risk of intracranial aneurysms. We hypothesized that this association is explained by a higher susceptibility to (one of) the eight trigger factors that were recently identified. We included 250 patients with aneurysmal subarachnoid hemorrhage. We calculated relative risks (RR) with 95% confidence intervals (95% CI) of aneurysmal rupture for trigger factors according to sex, age, site, and size of the aneurysms by means of the case-crossover design. None of the triggers except for physical exercise differed according to patient and aneurysm characteristics. In the hour after exposure to physical exercise: (1) patients over the age of 60 have a six-times-higher risk of rupture (RR 13; 95% CI 6.3-26) than those of 60 years of age and under (RR 2.3; 1.3-4.1); (2) aneurysms at the internal carotid artery have a higher risk than those at other locations (RR 17; 7.8-37), but this was only statistically significant when compared to anterior communicating artery aneurysms (RR 3.2; 1.6-6.1); (3) aneurysms 5 mm or smaller had a higher risk of rupture (RR 9.5; 4.6-19) than larger aneurysms (RR 2.4; 1.3-4.3); and (4) women and men had similar risks. A higher susceptibility to exercise might explain part of the higher risk of rupture in older patients. Why women and patients with aneurysms larger than 5 mm or posterior circulation aneurysms have a higher risk of rupture remains to be settled.     

Genes and outcome after aneurysmal subarachnoid haemorrhage

Objectives Initial and secondary ischaemia are important determinants of outcome after subarachnoid haemorrhage (SAH). Cerebral ischaemia is a potent stimulus for expression of genes that may influence recovery.We investigated whether functional polymorphisms in the apolipoprotein E (APOE), insulin–like growth factor-1 (IGF–1), tumor necrosis factor-A (TNF–A), interleukin-1A (IL–1A), interleukin-1B (IL–1B), and interleukin-6 (IL–6) genes are related with outcome after aneurysmal SAH. Methods Genotyping of the polymorphisms was performed in a consecutive series of 167 patients with aneurysmal SAH. The risk of a poor outcome was analysed with logistic regression with adjustment for prognostic factors for outcome after SAH, using the homozygotes for the wild type alleles as a reference. Results Patients carrying any IGF–1 non–wild type allele had a lower risk of a poor outcome (OR 0.4, 95% CI 0.2–1.0), while carriers of the TNF–A non–wild type allele had a higher risk (OR 2.3, 95% CI 1.0–5.4). We could not demonstrate an association with outcome for APOE (APOE4 OR 0.4, 95% CI 0.1–1.2; APOE 2 OR 0.7, 95% CI 0.2–2.4), IL–1A (OR 1.8, 95% CI 0.8–4.0), IL–1B (OR 0.7, 95% CI 0.3–1.5) and IL–6 (OR 0.7, 95% CI 0.3–1.8) polymorphisms. Conclusions Variation in some genes that are expressed after cerebral ischaemia may partly explain the large differences in outcome between patients with aneurysmal SAH. SAH patients homozygote for the IGF–1 wild type allele or carriers of the TNF–A non–wild type allele have a higher risk of poor outcome. Additional studies in other populations are needed to assess the generalisability of our results.     

Chlamydia pneumoniae infection as a risk factor for subarachnoid hemorrhage

Many risk factors for subarachnoid hemorrhage (SAH), such as hypertension and recent infection, have already been established. Chlamydia pneumoniae is a common respiratory pathogen that has been implicated as a potential risk factor for hypertension and atherosclerotic diseases. The purpose of the case-control study presented here was to examine the causative relationship between C. pneumoniae infection and SAH. Serum C. pneumoniae IgG and IgA antibodies were measured using an enzyme-linked immunosorbent assay in 52 patients with SAH and in 104 healthy age-matched control subjects. Multivariate analysis revealed a significant association between SAH and both a strong seropositivity for IgG and/or IgA antibodies against C. pneumoniae (odds ratio, OR, 3.62; 95% confidence intervals, CI, 1.06-12.39; p = 0.040), which indicates the presence of acute C. pneumoniae infection, and hypertension (OR, 2.91; 95% CI, 1.42-5.96; p = 0.0035). These results provide evidence that infection with C. pneumoniae may be a risk factor for SAH from a ruptured intracranial aneurysm.     

Cerebral inflammatory response and predictors of admission clinical grade after aneurysmal subarachnoid hemorrhage

Poor admission clinical grade is the most important determinant of outcome after aneurysmal subarachnoid hemorrhage (aSAH); however, little attention has been focused on independent predictors of poor admission clinical grade. We hypothesized that the cerebral inflammatory response initiated at the time of aneurysm rupture contributes to ultra-early brain injury and poor admission clinical grade. We sought to identify factors known to contribute to cerebral inflammation as well as markers of cerebral dysfunction that were associated with poor admission clinical grade. Between 1997 and 2008, 850 consecutive SAH patients were enrolled in our prospective database. Demographic data, physiological parameters, and location and volume of blood were recorded. After univariate analysis, significant variables were entered into a logistic regression model to identify significant associations with poor admission clinical grade (Hunt–Hess grade 4–5). Independent predictors of poor admission grade included a SAH sum score >15/30 (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.5–3.6), an intraventricular hemorrhage sum score >1/12 (OR 3.1, 95% CI 2.1–4.8), aneurysm size >10 mm (OR 1.7, 95% CI 1.1–2.6), body temperature ?38.3 °C (OR 2.5, 95% CI 1.1–5.4), and hyperglycemia >200 mg/dL (OR 2.7, 95% CI 1.6–4.5). In a large, consecutive series of prospectively enrolled patients with SAH, the inflammatory response at the time of aneurysm rupture, as reflected by the volume and location of the hemoglobin burden, hyperthermia, and perturbed glucose metabolism, independently predicts poor admission Hunt–Hess grade. Strategies for mitigating the inflammatory response to aneurysmal rupture in the hyper-acute setting may improve the admission clinical grade, which may in turn improve outcomes.