Attributable risk of common and rare determinants of subarachnoid hemorrhage

Prediction of aneurysmal subarachnoid hemorrhage in comparison with other stroke types using routine care data

Aneurysmal subarachnoid hemorrhage (aSAH) can be prevented by early detection and treatment of intracranial aneurysms in high-risk individuals. We investigated whether individuals at high risk of aSAH in the general population can be identified by developing an aSAH prediction model with electronic health records (EHR) data. To assess the aSAH model's relative performance, we additionally developed prediction models for acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) and compared the discriminative performance of the models. We included individuals aged ≥35 years without history of stroke from a Dutch routine care database (years 2007-2020) and defined outcomes aSAH, AIS and ICH using International Classification of Diseases (ICD) codes. Potential predictors included sociodemographic data, diagnoses, medications, and blood measurements. We cross-validated a Cox proportional hazards model with an elastic net penalty on derivation cohorts and reported the c-statistic and 10-year calibration on validation cohorts. We examined 1,040,855 individuals (mean age 54.6 years, 50.9% women) for a total of 10,173,170 person-years (median 11 years). 17,465 stroke events occurred during follow-up: 723 aSAH, 14,659 AIS, and 2,083 ICH. The aSAH model's c-statistic was 0.61 (95%CI 0.57-0.65), which was lower than the c-statistic of the AIS (0.77, 95%CI 0.77-0.78) and ICH models (0.77, 95%CI 0.75-0.78). All models were well-calibrated. The aSAH model identified 19 predictors, of which the 10 strongest included age, female sex, population density, socioeconomic status, oral contraceptive use, gastroenterological complaints, obstructive airway medication, epilepsy, childbirth complications, and smoking. Discriminative performance of the aSAH prediction model was moderate, while it was good for the AIS and ICH models. We conclude that it is currently not feasible to accurately identify individuals at increased risk for aSAH using EHR data.

Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Management of Hypertension and Associated Cardiovascular Disease in Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease is the most commonly inherited disease of the kidneys affecting an estimated 12,000,000 people in the world. Autosomal dominant polycystic kidney disease is a systemic disease, with a wide range of associated features that includes hypertension, valvular heart diseases, cerebral aneurysms, aortic aneurysms, liver cysts, abdominal hernias, diverticulosis, gross hematuria, urinary tract infections, nephrolithiasis, pancreatic cysts, and seminal vesicle cysts. The cardiovascular anomalies are somewhat different than in the general population and also chronic kidney disease population, with higher morbidity and mortality rates. This review will focus on cardiovascular diseases associated with autosomal dominant polycystic kidney disease and their management.

Sex differences and risk factors for bleeding in Alagille syndrome

Spontaneous bleeds are a leading cause of death in the pediatric JAG1-related liver disease Alagille syndrome (ALGS). We asked whether there are sex differences in bleeding events in patients, whether Jag1^Ndr/Ndr mice display bleeds or vascular defects, and whether discovered vascular pathology can be confirmed in patients non-invasively. We performed a systematic review of patients with ALGS and vascular events following PRISMA guidelines, in the context of patient sex, and found significantly more girls than boys reported with spontaneous intracranial hemorrhage. We investigated vascular development, homeostasis, and bleeding in Jag1^Ndr/Ndr mice, using retina as a model. Jag1^Ndr/Ndr mice displayed sporadic brain bleeds, a thin skull, tortuous blood vessels, sparse arterial smooth muscle cell coverage in multiple organs, which could be aggravated by hypertension, and sex-specific venous defects. Importantly, we demonstrated that retinographs from patients display similar characteristics with significantly increased vascular tortuosity. In conclusion, there are clinically important sex differences in vascular disease in ALGS, and retinography allows non-invasive vascular analysis in patients. Finally, Jag1^Ndr/Ndr mice represent a new model for vascular compromise in ALGS.

Spontaneous subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) is the third most common subtype of stroke. Incidence has decreased over past decades, possibly in part related to lifestyle changes such as smoking cessation and management of hypertension. Approximately a quarter of patients with SAH die before hospital admission; overall outcomes are improved in those admitted to hospital, but with elevated risk of long-term neuropsychiatric sequelae such as depression. The disease continues to have a major public health impact as the mean age of onset is in the mid-fifties, leading to many years of reduced quality of life. The clinical presentation varies, but severe, sudden onset of headache is the most common symptom, variably associated with meningismus, transient or prolonged unconsciousness, and focal neurological deficits including cranial nerve palsies and paresis. Diagnosis is made by CT scan of the head possibly followed by lumbar puncture. Aneurysms are commonly the underlying vascular cause of spontaneous SAH and are diagnosed by angiography. Emergent therapeutic interventions are focused on decreasing the risk of rebleeding (ie, preventing hypertension and correcting coagulopathies) and, most crucially, early aneurysm treatment using coil embolisation or clipping. Management of the disease is best delivered in specialised intensive care units and high-volume centres by a multidisciplinary team. Increasingly, early brain injury presenting as global cerebral oedema is recognised as a potential treatment target but, currently, disease management is largely focused on addressing secondary complications such as hydrocephalus, delayed cerebral ischaemia related to microvascular dysfunction and large vessel vasospasm, and medical complications such as stunned myocardium and hospital acquired infections.

Aneurysmal subarachnoid hemorrhage in Germany between 2005 and 2018: a nationwide observational study

BACKGROUND

In recent decades, the global incidence of aneurysmal subarachnoid hemorrhage (aSAH) has declined. However, significant regional differences exist. We present the first comprehensive analysis of time trends in the incidence of aSAH and case fatality in Germany.

METHODS

All patients hospitalized with aSAH in Germany between 2005 and 2018 were identified using International classification of disease (ICD10) codes I60.0 to I60.7.

RESULTS

A total of 101,105 cases were included. The incidence of aSAH in Germany decreased at a mean annual rate of 0.5 % (p=0.003) from 8.9 per 100,000 population in 2005 to 8.2 in 2018. Over time, incidences of aSAH declined among patients younger than 55 years and patients aged 70-79 years, increased among ages 60-64 years and remained stable in age groups 65-69 and 85-89 years. This corresponded to an increase in the mean age of aSAH onset from 55.6 (±14.3) to 59.0 (±14.0) years. Throughout the study period, the mean age of aSAH onset was higher in women compared to men (58.3 ±14.4 years vs. 56.1 ±14.1 years). There were no changes in in-hospital case fatality (16.2 vs. 16.6%, p=0.18), but the duration of hospital stay increased significantly from 19.7 to 24.8 days (p<0.001). The most frequent aSAH associated aneurysm location was the anterior circulation throughout the entire study period.

CONCLUSIONS

In Germany, the incidence of aSAH decreased between 2005 and 2018, especially in younger parts of the population. This may reflect effects of lifestyle adjustments most pronounced in younger age groups.

Subarachnoid Hemorrhage

PURPOSE OF REVIEW

Subarachnoid hemorrhage (SAH) remains an important cause of mortality and long-term morbidity. This article uses a case-based approach to guide readers through the fundamental epidemiology and pathogenesis of SAH, the approach to diagnosis and management, the results of clinical trials and evidence to date, prognostic considerations, controversies, recent developments, and future directions in SAH.

RECENT FINDINGS

Historically, management of SAH focused on prevention and treatment of subsequent cerebral vasospasm, which was thought to be the primary cause of delayed cerebral ischemia. Clinical and translational studies over the past decade, including several therapeutic phase 3 randomized clinical trials, suggest that the pathophysiology of SAH-associated brain injury is multiphasic and multifactorial beyond large vessel cerebral vasospasm. The quest to reduce SAH-associated brain injury and improve outcomes is shifting away from large vessel cerebral vasospasm to a new paradigm targeting multiple brain injury mechanisms, including early brain injury, delayed cerebral ischemia, microcirculatory dysfunction, spreading cortical depolarization, inflammation, and the brain-body interaction in vascular brain injury with critical illness.Despite multiple negative randomized clinical trials in search of potential therapeutic agents ameliorating the downstream effects after SAH, the overall outcome of SAH has improved over recent decades, likely related to improvements in interventional options for ruptured cerebral aneurysms and in critical care management. Emerging clinical evidence also suggests potential harmful impact of historic empiric treatments for SAH-associated vasospasm, such as prophylactic induction of hypertension, hypervolemia, and hemodilution (triple H therapy).With decreasing mortality, long-term SAH survivorship and efforts to reduce chronic morbidity and to improve quality of life and patient-centered outcome are growing areas of unmet need. Despite existing guidelines, significant variabilities in local and regional practices and in scientific terminologies have historically limited advancement in SAH care and therapeutic development. Large global collaborative efforts developed harmonized SAH common data elements in 2019, and studies are under way to examine how existing variabilities in SAH care impact long-term SAH outcomes.

SUMMARY

Although the overall incidence and mortality of SAH is decreasing with advances in preventive and acute care, SAH remains a major cause of long-term morbidity in survivors. Significant variabilities in care settings and empiric treatment protocols and inconsistent scientific terminologies have limited advancement in patient care and therapeutic clinical studies. Large consensus efforts are under way to introduce clinical guidelines and common data elements to advance therapeutic approaches and improve patient outcome.

Dyslipidemia and rupture risk of intracranial aneurysms-a systematic review

Dyslipidemia is a well-established risk factor for coronary artery disease. However, the effect on cerebral artery disease, and more specifically the rupture risk of intracranial aneurysms, is unclear and has not yet been reviewed. We therefore performed a systematic review to investigate associations between different types of dyslipidemia and incidence of aneurysmal subarachnoid hemorrhage (aSAH). We used the MEDLINE, Embase, and Web of Science databases to identify clinical trials that compared the rupture risk among SAH patients with or without dyslipidemia. The risk of bias in each included study was evaluated using the Critical Appraisal Skills Program (CASP). Of 149 unique citations from the initial literature search, five clinical trials with a case-control design met our eligibility criteria. These studies compared aSAH patients to patients with unruptured aneurysms and found an overall inverse relationship between hypercholesterolemia and rupture risk of intracranial aneurysms. The quality assessment classified all included studies as high risk of bias. The evidence indicates that hypercholesterolemia is associated with a reduced rupture risk of intracranial aneurysms. However, it is not clear whether this relation is due to the dyslipidemic condition itself or the use of antihyperlipidemic medication.

Volumes, outcomes, and complications after surgical versus endovascular treatment of aneurysms in the United States (1993–2015): continued evolution versus steady-state after more than 2 decades of practice

OBJECTIVE

Adoption of endovascular treatment (EVT) and other advances in aneurysm care have shifted practice patterns of cerebral aneurysm treatment over the past 2 decades in the US. The objective of this study was to determine whether resulting trends in volumes, outcomes, and complications have matured in general practice or continue to evolve.

METHODS

Data were obtained from the National Inpatient Sample from 1993 to 2015. ICD-9 codes were used to estimate annual volumes, outcomes, and complications following treatment of ruptured and unruptured aneurysms. Univariate and multivariate analyses were used to estimate risk ratios for complications and outcomes. Trends in time were assessed utilizing annual percentage change (APC).

RESULTS

The authors found a nearly 5-fold increase in annual admissions with diagnoses of unruptured aneurysms, whereas SAH volume increased less than 50%. Clipping ruptured aneurysms steadily declined (APC −0.86%, p = 0.69 until 1999, then −6.22%, p < 0.001 thereafter), whereas clipping unruptured aneurysms slightly increased (APC 2.02%, p < 0.001). EVT tripled in 2002–2004 and steadily increased thereafter (APC 7.22%, p < 0.001 and 5.85%, p = 0.01 for unruptured and ruptured aneurysms, respectively). Despite a 3-fold increase in both diagnosis and treatment of unruptured aneurysms, the incidence of SAH remained steady at 12 per 100,000 persons per year (APC 0.04%, p = 0.83). In contrast, SAH severity increased over time, as did patient age and comorbidities (all p < 0.001). SAH led to nonroutine discharge more frequently over time after both EVT and clipping (APC 1.24% and 1.10%, respectively), although mortality decreased during the same time (APC −2.48% and −1.44%, respectively). Complications were more frequent after clipping than EVT, but this differential risk diminished during the study period and was less perceptible in ruptured aneurysms. The proportion of patients discharged home after treatment of unruptured aneurysms was significantly lower (p < 0.001) after clipping (69.3%–79.5%) than EVT (88.3%–93.3%); both proportions changed minimally since 1998 (APC −0.39%, p = 0.02, and APC −0.11%, p = 0.14, respectively).

CONCLUSIONS

EVT volume markedly increased for ruptured and unruptured aneurysms from 1993 to 2015, whereas clipping decreased for ruptured and slightly increased for unruptured aneurysms. The incidence of SAH remained unchanged despite increased diagnosis and treatment of unruptured aneurysms. In ruptured aneurysms, SAH severity has increased over time, as have age, comorbidities, and nonroutine discharges. In contrast, routine discharge after treatment of unruptured aneurysms remains largely unchanged since 1998 and remains lower with clipping.

Heritability of territory of ruptured and unruptured intracranial aneurysms in families

BACKGROUND

A previous study suggested that intracranial aneurysms are more likely to occur in the same arterial territory within families. We aimed to replicate this analysis in independent families and in a sample limited to intracranial aneurysms that ruptured.

METHODS

Among families with ≥2 first-degree relatives with intracranial aneurysms, we randomly matched index families to comparison families, and compared concordance in intracranial aneurysm territory between index and comparison families using a conditional logistic events/trials model. We analyzed three European cohorts separately, and pooled the results with those of the Familial Intracranial Aneurysm study by performing an inverse variance fixed effects meta-analysis. The main analysis included both unruptured and ruptured intracranial aneurysms, and a secondary analysis only ruptured intracranial aneurysms.

RESULTS

Among 70 Dutch, 142 Finnish, and 34 French families, concordance regarding intracranial aneurysm territory was higher within families than between families, although not statistically significant. Meta-analysis revealed higher concordance in territory within families overall (odds ratio [OR] 1.7, 95%CI 1.3-2.2) and for each separate territory except the anterior cerebral artery. In the analysis of ruptured intracranial aneurysms, overall territory concordance was higher within families than between families (OR 1.8; 95%CI 1.1-2.7) but the territory-specific analysis showed statistical significance only for the internal carotid artery territory.

CONCLUSIONS

We confirmed that familial intracranial aneurysms are more likely to occur in the same arterial territory within families. Moreover, we found that ruptured aneurysms were also more likely to occur in the same arterial territory within families.

Unilateral absence of the internal carotid artery associated with anterior communicating artery aneurysms: Systematic review and a proposed management algorithm

Background:

Absence or hypoplasia of the internal carotid artery (ICA) is a rare congenital anomaly that is mostly unilateral and highly associated with other intracranial vascular anomalies, of which saccular aneurysm is the most common. Blood flow to the circulation of the affected side is maintained by collateral pathways, some of which include the anterior communicating artery (Acom) as part of their anatomy. Therefore, temporary clipping during microsurgery on Acom aneurysms in patients with unilateral ICA anomalies could jeopardize these collaterals and place the patient at risk of ischemic damage. In this paper, we review the literature on cases with a unilaterally absent ICA associated with Acom aneurysms and provide an illustrative case.

Methods:

We combined our experience of one case of a unilaterally absent ICA associated with an Acom aneurysm with the 33 existing publications on the same subject in the literature, for a total of 40 cases. We provide a detailed systematic literature review of this association of vascular anomalies, exploring different aspects regarding the collateral pathways and how they impact management strategies and propose a management algorithm to deal with such association.

Results:

The mean age was 48.2 ± 16.5 years. The aneurysmal rupture was the most common presentation (75%). Agenesis was observed in 70% of patients, followed by hypoplasia (20%) and, finally, aplasia (10%). Lie Type A was the most common pattern of collaterals (50%), with Types B and D being of almost equal proportions. Most aneurysms were located at the A1-Acom junction contralateral to the anomalous side (Fisher’s Exact test; P = 0.03). One case of temporary clipping was reported in the literature.

Conclusion:

Acom aneurysms in patients with unilateral ICA anomalies, given they are more commonly present contralaterally, could be of acquired etiology, warranting periodic screening in asymptomatic patients. Temporary clipping might be safe in patients with Type D collateral pattern, while those with Types A or B may require intraoperative rupture risk assessment and a tailored management plan to avoid disrupting collateral flow and causing ischemia.

A Direct Correlation between Red Blood Cell Indices and Cognitive Impairment After Aneurysmal Subarachnoid Hemorrhage (aSAH)

BACKGROUND

Cognitive impairment can occur after aneurysmal subarachnoid hemorrhage (aSAH) though it commonly tends to be neglected. Red blood cell (RBC) indices are associated with long-term functional outcomes, while it is unclear whether RBC indices could be a potential predictor of cognitive decline after aSAH. We aimed to investigate the association between RBC indices and post-aSAH cognitive impairment at 1 year.

METHODS

Patients with aSAH received neuropsychological test by the Montreal Cognitive Assessment (MoCA) and underwent serum and cerebrospinal fluid (CSF) samples test. To determine the association between RBC indices and cognitive impairment after acute aSAH, we adjusted for demographic and vascular risk factors using multivariate logistic regression analysis.

RESULTS

Of the 126 patients included in this study, 33% (42/126) of them were diagnosed with cognitive impairment (MoCA＜26). After adjustment for potential confounders, increased mean corpuscular volume (MCV) (OR: 1.36, 95%CI: 1.19-1.55) and mean corpuscular hemoglobin (MCH) (OR: 1.61, 95%CI: 1.25-2.08), reflecting systemic iron status, are more likely to be associated with cognitive impairment after aSAH.

CONCLUSION

In this aSAH population, our data shows the positive association between MCH and MCV and cognitive impairment at 1 year.

Population-based stroke surveillance using big data: state-wide epidemiological trends in admissions and mortality in New South Wales, Australia

OBJECTIVES

Epidemiological trends for major causes of death and disability, such as stroke, may be monitored using administrative data to guide public health initiatives and service delivery.

METHODS

We calculated admissions rates for ischaemic stroke, intracerebral haemorrhage and subarachnoid haemorrhage between 1 January 2005 and December 31^st, 2013 and rates of 30-day mortality and 365-day mortality in 30-day survivors to 31 December 2014 for patients aged 15 years or older from New South Wales, Australia. Annual Average Percentage Change in rates was estimated using negative binomial regression.

RESULTS

Of 81,703 eligible admissions, 64,047 (78.4%) were ischaemic strokes and 13,302 (16.3%) and 4,778 (5.8%) were intracerebral and subarachnoid haemorrhages, respectively. Intracerebral haemorrhage admissions significantly declined by an average of 2.2% annually (95% Confidence Interval = -3.5% to -0.9%) (p < 0.001). Thirty-day mortality rates significantly declined for ischaemic stroke (Average Percentage Change -2.9%, 95% Confidence Interval = -5.2% to -1.0%) (p = 0.004) and subarachnoid haemorrhage (Average Percentage Change = -2.6%, 95% Confidence Interval = -4.8% to -0.2%) (p = 0.04). Mortality at 365-days amongst 30-day survivors of ischaemic stroke and intracerebral haemorrhage was stable over time and increased in subarachnoid haemorrhage (Annual Percentage Change 6.2%, 95% Confidence Interval = -0.1% to 12.8%), although not significantly (p = 0.05).

DISCUSSION

Improved prevention may have underpinned declining intracerebral haemorrhage rates while survival gains suggest that innovations in care are being successfully translated. Mortality in patients surviving the acute period is unchanged and may be increasing for subarachnoid haemorrhage warranting investment in post-discharge care and secondary prevention.

Exome sequencing reveals a novel variant in NFX1 causing intracranial aneurysm in a Chinese family

BACKGROUND

Genetic risk factors play an important role in the pathogenesis of familial intracranial aneurysms (FIAs); however, the molecular mechanisms remain largely unknown.

OBJECTIVE

To investigate potential FIA-causing genetic variants by rare variant interrogation and a family-based genomics approach in a large family with an extensive multigenerational pedigree with FIAs.

METHOD

Exome sequencing (ES) was performed in a dominant likely family with intracranial aneurysms (IAs). Variants were analyzed by an in-house developed pipeline and prioritized using various filtering strategies, including population frequency, variant type, and predicted variant pathogenicity. Sanger sequencing was also performed to evaluate the segregation of the variants with the phenotype.

RESULTS

Based on the ES data obtained from five individuals from a family with 7/21 living members affected with IAs, a total of 14 variants were prioritized as candidate variants. Familial segregation analysis revealed that NFX1 c.2519T>C (p.Leu840Pro) segregated in accordance with Mendelian expectations with the phenotype within the family-that is, present in all IA-affected cases and absent from all unaffected members of the second generation. This missense variant is absent from public databases (1000genome, ExAC, gnomAD, ESP5400), and has damaging predictions by bioinformatics tools (Gerp ++ score = 5.88, CADD score = 16.43, MutationTaster score = 1, LRT score = 0). In addition, 840Leu in NFX1 is robustly conserved in mammals and maps in a region before the RING-type zinc finger domain.

CONCLUSION

NFX1 c.2519T>C (p.Leu840Pro) may contribute to the pathogenetics of a subset of FIAs.

Common Data Elements for Subarachnoid Hemorrhage and Unruptured Intracranial Aneurysms: Recommendations from the Working Group on Subject Characteristics

BACKGROUND

The National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDEs) have been generated to standardize and define terms used by the scientific community. The widespread use of these CDEs promotes harmonized data collection in clinical research. The aim of the NINDS Unruptured Intracranial Aneurysms (UIA) and Subarachnoid Hemorrhage (SAH), and Subject Characteristics working group (WG) was to identify, define, and classify CDEs describing the characteristics of patients diagnosed with an UIA and SAH. Thus, "Participant/Subject characteristics" is a set of factors defining a population of selected individuals and allowing comparisons with a reference population and overtime.

METHODS

Based on standard terms defined by the United States' Census Bureau, CDEs previously defined by several (Stroke, Epilepsy and Traumatic Brain Injury) NINDS CDE working groups literature and expert opinion of the WG, the "Participant/Subject characteristics" domain has been defined.

RESULTS

A set of 192 CDEs divided in 7 subsections: demographics (8 CDEs), social status (8 CDEs), behavioral status (22 CDEs), family and medical history (144 CDEs), pregnancy and perinatal history (8 CDEs), history data source reliability (3 CDEs), and prior functional status (3 CDEs) was defined. SAH is characterized by 6 core elements, all classified in the "Participant/Subject characteristics" domain. Four exploratory elements out of the 39 for SAH overall are in the "Participant/Subject characteristics" domain, and all remaining 182 CDEs in the "Participant/Subject characteristics" domain are classified as Supplemental-Highly Recommended elements.

CONCLUSIONS

These CDEs would allow the development of best practice guidelines to standardize the assessment and reporting of observations concerning UIA and SAH.

Determining rural risk for aneurysmal subarachnoid hemorrhages: A structural equation modeling approach

An aneurysmal subarachnoid hemorrhage (aSAH) carries a high disability burden. The true impact of rurality as a predictor of outcome severity is unknown. Our aim is to clarify the relationship between the proposed explanations of regional and rural health disparities linked to severity of outcome following an aSAH. An initial literature search identified limited data directly linking geographical location, rurality, rural vulnerability, and aSAH. A further search noting parallels with ischemic stroke and acute myocardial infarct literature presented a number of diverse and interrelated predictors. This a priori knowledge informed the development of a conceptual framework that proposes the relationship between rurality and severity of outcome following an aSAH utilizing structural equation modeling. The presented conceptual framework explores a number of system, environmental, and modifiable risk factors. Socioeconomic characteristics, modifiable risk factors, and timely treatment that were identified as predictors of severity of outcome following an aSAH and within each of these defined predictors a number of contributing specific individual predictors are proposed. There are considerable gaps in the current knowledge pertaining to the impact of rurality on the severity of outcome following an aSAH. Absent from the literature is any investigation of the cumulative impact and multiplicity of risk factors associated with rurality. The proposed conceptual framework hypothesizes a number of relationships between both individual level and system level predictors, acknowledging that intervening predictors may mediate the effect of one variable on another.

Inflammatory changes in the aneurysm wall: a review

Rupture of a saccular intracranial artery aneurysm (IA) causes subarachnoid hemorrhage, a significant cause of stroke and death. The current treatment options, endovascular coiling and clipping, are invasive and somewhat risky. Since only some IAs rupture, those IAs at risk for rupture should be identified. However, to improve the imaging of rupture-prone IAs and improve IA treatment, IA wall pathobiology requires more thorough knowledge. Chronic inflammation has become understood as an important phenomenon in IA wall pathobiology, featuring inflammatory cell infiltration as well as proliferative and fibrotic remodulatory responses. We review the literature on what is known about inflammation in the IA wall and also review the probable mechanisms of how inflammation would result in the degenerative changes that ultimately lead to IA wall rupture. We also discuss current options in imaging inflammation and how knowledge of inflammation in IA walls may improve IA treatment.

Cardiac events within one year after a subarachnoid haemorrhage: The predictive value of troponin elevation after aneurysm occlusion

BACKGROUND

Patients who survive after an aneurysmal subarachnoid haemorrhage (ASAH) have an increased incidence of cardiovascular events compared with the general population. We assessed whether troponin elevation after aneurysm occlusion, as marker of myocardial injury, can predict long-term cardiac events.

METHODS

We analysed a prospectively collected cohort of 159 patients with ASAH and early aneurysm occlusion, in whom routine post-intervention troponin I (TnI) measurements were performed. With competing risk regression modelling we estimated the association between TnI elevation after aneurysm occlusion and major adverse cardiac events within one year. Secondary outcome measures were all-cause mortality and neurological condition within one year. The predictive value of post-intervention TnI was compared with the predictive value of pre-intervention characteristics using c-statistics and the integrated discrimination improvement index.

RESULTS

Subdistribution hazard ratios for TnI elevation and major adverse cardiac events at one year were 1.05 (95% confidence interval (CI) 1.03-1.07) per 10 ng/l increase in TnI and 7.91 (95% CI 1.46-43.0) for any TnI elevation. After adjustment for pre-intervention variables, the subdistribution hazard ratios were 1.47 (95% CI 0.81-2.67) per 10 ng/l and 9.00 (95% CI 1.62-50.1) for any elevation. The c-statistic was 0.71 for TnI elevation as a continuous measure and 0.69 for any TnI elevation. The integrated discrimination improvement index showed a minimum improvement in prediction of 0.08 (interquartile range 0.06 to 0.09) for TnI as a continuous measure and 0.003 (interquartile range -0.004 to 0.01) for any TnI elevation, when compared with pre-intervention characteristics.

CONCLUSION

TnI elevation after occlusion of a ruptured intracranial aneurysm predicts the occurrence of a major adverse cardiac event within one year after ASAH.

PHASES score applied to a prospective cohort of aneurysmal subarachnoid hemorrhage patients

The treatment of unruptured intracranial aneurysms remains controversial. The PHASES score was developed to predict the 5-year risk of aneurysm rupture. We have assigned PHASES scores to a cohort of aneurysmal subarachnoid hemorrhage (aSAH) patients to assess the distribution of scores and its ability to predict outcome. In this study, the PHASES score was applied to a prospective cohort of aSAH patients that were enrolled in the Cerebral Aneurysm Renin Angiotensin System (CARAS) study. The CARAS study enrolled patients from two academic institutions in the United States from 2012 to 2015. Univariable and multivariable analyses were performed to identify factors predictive of outcome at last follow up. One hundred and forty-nine aSAH patients were included with a mean age of 54.9 ± 12.5 years. Most ruptured aneurysms were <7 mm (62.4%) and located in the anterior circulation (80.5%). Favorable functional outcome (mRS 0-2) at last follow up was achieved in 61.7% of patients. PHASES scores ranged from 0 to 16 with a median of 5; the majority of patients had a score of 4 (20.1%) or 5 (32.2%). Multivariable modeling identified higher PHASES scores (OR 1.235, CI 1.016-1.501, p = 0.034) and higher Hunt and Hess grades (OR 2.224, CI 1.353-3.655, p = 0.002) as independent predictors of poor functional outcome (mRS 3-6) at last follow up. The majority of aSAH patients present with low (≤5) PHASES scores. Elevated PHASES scores are independently associated with poor functional outcome in patients with aSAH.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Age-Specific Vascular Risk Factor Profiles According to Stroke Subtype

BACKGROUND

Ischemic and hemorrhagic stroke are increasingly recognized as heterogeneous diseases with distinct subtypes and etiologies. Information on variation in distribution of vascular risk factors according to age in stroke subtypes is limited. We investigated the prevalence of vascular risk factors in stroke subtypes in relation to age.

METHODS AND RESULTS

We studied a prospective multicenter university hospital-based cohort of 4033 patients. For patients with ischemic stroke caused by large artery atherosclerosis, small vessel disease, or cardioembolism and for patients with spontaneous intracerebral hemorrhage or aneurysmal subarachnoid hemorrhage, we calculated prevalences of vascular risk factors in 4 age groups: <55, 55 to 65, 65 to 75, and ≥75 years, and mean differences with 95% CIs in relation to the reference age group. Patients aged <55 years were significantly more often of non-white origin (in particular in spontaneous intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage patients) and most often smoked (most prominent for aneurysmal subarachnoid hemorrhage patients). Patients aged <55 years with ischemic stroke caused by large artery atherosclerosis or small vessel disease more often had hypertension, hyperlipidemia, and diabetes mellitus than patients with ischemic stroke of cardiac origin. Overall, the frequency of hypertension, hyperlipidemia, and diabetes mellitus increased with age among all stroke subtypes, whereas smoking decreased with age. Regardless of age, accumulation of potentially modifiable risk factors was most pronounced in patients with ischemic stroke caused by large artery atherosclerosis or small vessel disease.

CONCLUSIONS

The prevalence of common cardiovascular risk factors shows different age-specific patterns among various stroke subtypes. Recognition of these patterns may guide tailored stroke prevention efforts aimed at specific risk groups.

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.

A 54-year-old man with 12 intracranial aneurysms and familial subarachnoid hemorrhage: case report

Unruptured intracranial aneurysms occur in 1-3 % of the general population, and the risk of rupture is generally considered to be low. However, patients with multiple aneurysms and familial predisposition carry a particular risk of subarachnoid hemorrhage (SAH). A 54-year-old hypertensive man underwent screening with a head CT angiography (CTA) because of his comorbidities. CTA revealed multiple bilateral aneurysms around the circle of Willis. At first surgery, seven aneurysms were clipped (BA, ACOM, ICA ×2, and MCA ×3), two of which were detected intraoperatively only. During the second surgery, another three aneurysms were surgically clipped (PCOM and MCA ×2), one of which was detected intraoperatively. Follow-up angiography revealed another two aneurysms. A PCOM aneurysm was treated by coil embolization and a VA aneurysm clipped surgically during a third admission. The patient made an uneventful recovery. However, 4 months after his second surgery, his daughter underwent surgical clipping of a right-sided ICA aneurysm. This case report highlights both the importance of screening of high risk patients with family history of SAH, as well as its limitations, as our patient developed two de novo aneurysms during 6-month follow-up and CTA preoperatively missed three small aneurysms.

Incidence and Mortality of Spontaneous Subarachnoid Hemorrhage in Martinique

BACKGROUND

Incidence of spontaneous subarachnoid hemorrhages (SAH) varies wildly across the world and seems to be low in Central and South America (4.2 per 100 000 person-years; CI 95%; 3.1-5.7). The objective of our study was to describe the characteristics of SAH and to estimate its incidence and severity in Martinique, a small French island located in the Caribbean Sea.

METHODS

Due to its insular nature and small captive population, Martinique is ideal for the setting up of population-based epidemiological studies with good exhaustiveness. Our study, spanning a 7 year period (2007-2013), consisted of retrospective case ascertainment with multiple overlapping methods. Crude incidence and 30 day case-fatality rates for SAH among the Martinican population were computed for the study period. Incidence and disease severity was also analyzed according to age, gender and aneurysm presence. World age-standardized incidence rates were also calculated.

RESULTS

A total of 121 patients had a SAH during the study period, with a higher frequency of female cases (71.1% versus 28.9%, p<0.001). Patient mean age was 57.1 years (median = 55 [46-66]). An aneurysmal origin was found in 96 SAH cases (79.3%). Crude annual incidence was 4.36 per 100 000 person-years (CI 95% 2.30-6.42). World age-standardized incidence was 3.29 per 100 000 person-years (CI 95% 1.74-4.84). During the 30 days following SAH diagnosis, 29 patients died (case fatality rate: 24% (CI 95% 16.4-31.6)).

CONCLUSIONS

The incidence of spontaneous subarachnoid hemorrhage in Martinique is much lower than in other parts of the world and similar to countries in Central and South America. These results are possibly related to environmental factors and most particularly to a low rate of smoking in the Martinican population. Thirty-day case-fatality rate is similar to what is observed in developed countries.

Adenosine-induced transient asystole

Cerebral aneurysms are an important health issue in the United States, and the mortality rate following aneurysm rupture, or SAH, remains high. The treatment of these aneurysms uses endovascular options which include coil placement, stent assistant coiling and, recently, flow diversion. However, microsurgical clipping remains an option in those aneurysms not suited for endovascular therapy. These are often the more complicated aneurysms such as in large, giant aneurysms or deep-seated aneurysms. Circumferential visualization of the aneurysm, parent vessels, branches, perforators, and other neurovascular structures is important to prevent residual aneurysms or strokes from vessel or perforator occlusion. Decompression of the aneurysm sac is often required and we believe that adenosine-induced transient asystole should be an important option for clipping of complex cerebral aneurysms.

Improved survival after non-traumatic subarachnoid haemorrhage with structured care pathways and modern intensive care

OBJECTIVE

Patients with subarachnoid haemorrhage (SAH) often require multidisciplinary management and their treatment is difficult to standardize. The aim was to describe baseline characteristics, care pathways and discharge status in an unselected group of patients with first ever non-traumatic SAH, and to examine whether their care pathways and outcomes vary.

METHODS

Patients admitted with first ever non-traumatic SAH to a neurosurgical unit (NSU) in Sweden during a period of 18 months in 2009-2010 were included. The data was retrospectively collected from patient charts.

RESULTS

A total of 131 patients were admitted with first ever non-traumatic SAH. Forty-nine (37%) patients initially sought medical care nearby the NSU and 82 (63%) in other parts of the catchment area. The average age was 55.5 years and 79 (60%) were female. In 98 (75%) cases, a ruptured aneurysm was found to be the cause of SAH. There was a significant correlation between poor clinical grade at admission and poor patient outcome (p<0.0005). No significant correlation between early aneurysm treatment and improved clinical outcome were seen. No significant differences in outcome were seen between patients who initially sought medical care nearby the NSU and those in other parts of the catchment area. There was no difference seen in the number of patients who had follow-up at the NSU depending on where they initially sought help.

CONCLUSION

This study shows an improvement in survival after SAH compared to earlier studies in Sweden. The results are indicative of effective management of all patients with SAH in the catchment area that are treated at the NSU. A nationwide registry to assess the overall management of patients treated for SAH would be useful to further investigate patients with SAH.

Smoking is a negative predictor of arteriovenous malformation posttreatment obliteration: analysis of vascular risk factors in 774 patients

OBJECT

Cigarette smoking has been well established as a risk factor in vascular pathology, such as cerebral aneurysms. However, tobacco's implications for patients with cerebral arteriovenous malformations (AVMs) are controversial. The object of this study was to identify predictors of AVM obliteration and risk factors for complications.

METHODS

The authors conducted a retrospective analysis of a prospectively maintained database for all patients with AVMs treated using surgical excision, staged endovascular embolization (with N-butyl-cyanoacrylate or Onyx), stereotactic radiosurgery (Gamma Knife or Linear Accelerator), or a combination thereof between 1994 and 2010. Medical risk factors, such as smoking, abuse of alcohol or intravenous recreational drugs, hypercholesterolemia, diabetes mellitus, hypertension, and coronary artery disease, were documented. A multivariate logistic regression analysis was conducted to detect predictors of periprocedural complications, obliteration, and posttreatment hemorrhage.

RESULTS

Of 774 patients treated at a single tertiary care cerebrovascular center, 35% initially presented with symptomatic hemorrhage and 57.6% achieved complete obliteration according to digital subtraction angiography (DSA) or MRI. In a multivariate analysis a negative smoking history (OR 1.9, p = 0.006) was a strong independent predictor of AVM obliteration. Of the patients with obliterated AVMs, 31.9% were smokers, whereas 45% were not (p = 0.05). Multivariate analysis of obliteration, after controlling for AVM size and location (eloquent vs noneloquent tissue), revealed that nonsmokers were more likely (0.082) to have obliterated AVMs through radiosurgery. Smoking was not predictive of treatment complications or posttreatment hemorrhage. Abuse of alcohol or intravenous recreational drugs, hypercholesterolemia, diabetes mellitus, and coronary artery disease had no discernible effect on AVM obliteration, periprocedural complications, or posttreatment hemorrhage.

CONCLUSIONS

Cerebral AVM patients with a history of smoking are significantly less likely than those without a smoking history to have complete AVM obliteration on follow-up DSA or MRI. Therefore, patients with AVMs should be strongly advised to quit smoking.

High risk population isolate reveals low frequency variants predisposing to intracranial aneurysms

3% of the population develops saccular intracranial aneurysms (sIAs), a complex trait, with a sporadic and a familial form. Subarachnoid hemorrhage from sIA (sIA-SAH) is a devastating form of stroke. Certain rare genetic variants are enriched in the Finns, a population isolate with a small founder population and bottleneck events. As the sIA-SAH incidence in Finland is >2× increased, such variants may associate with sIA in the Finnish population. We tested 9.4 million variants for association in 760 Finnish sIA patients (enriched for familial sIA), and in 2,513 matched controls with case-control status and with the number of sIAs. The most promising loci (p<5E-6) were replicated in 858 Finnish sIA patients and 4,048 controls. The frequencies and effect sizes of the replicated variants were compared to a continental European population using 717 Dutch cases and 3,004 controls. We discovered four new high-risk loci with low frequency lead variants. Three were associated with the case-control status: 2q23.3 (MAF 2.1%, OR 1.89, p 1.42×10-9); 5q31.3 (MAF 2.7%, OR 1.66, p 3.17×10-8); 6q24.2 (MAF 2.6%, OR 1.87, p 1.87×10-11) and one with the number of sIAs: 7p22.1 (MAF 3.3%, RR 1.59, p 6.08×-9). Two of the associations (5q31.3, 6q24.2) replicated in the Dutch sample. The 7p22.1 locus was strongly differentiated; the lead variant was more frequent in Finland (4.6%) than in the Netherlands (0.3%). Additionally, we replicated a previously inconclusive locus on 2q33.1 in all samples tested (OR 1.27, p 1.87×10-12). The five loci explain 2.1% of the sIA heritability in Finland, and may relate to, but not explain, the increased incidence of sIA-SAH in Finland. This study illustrates the utility of population isolates, familial enrichment, dense genotype imputation and alternate phenotyping in search for variants associated with complex diseases.

European Stroke Organization guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage

BACKGROUND

Intracranial aneurysm with and without subarachnoid haemorrhage (SAH) is a relevant health problem: The overall incidence is about 9 per 100,000 with a wide range, in some countries up to 20 per 100,000. Mortality rate with conservative treatment within the first months is 50-60%. About one third of patients left with an untreated aneurysm will die from recurrent bleeding within 6 months after recovering from the first bleeding. The prognosis is further influenced by vasospasm, hydrocephalus, delayed ischaemic deficit and other complications. The aim of these guidelines is to provide comprehensive recommendations on the management of SAH with and without aneurysm as well as on unruptured intracranial aneurysm.

METHODS

We performed an extensive literature search from 1960 to 2011 using Medline and Embase. Members of the writing group met in person and by teleconferences to discuss recommendations. Search results were graded according to the criteria of the European Federation of Neurological Societies. Members of the Guidelines Committee of the European Stroke Organization reviewed the guidelines.

RESULTS

These guidelines provide evidence-based information on epidemiology, risk factors and prognosis of SAH and recommendations on diagnostic and therapeutic methods of both ruptured and unruptured intracranial aneurysms. Several risk factors of aneurysm growth and rupture have been identified. We provide recommendations on diagnostic work up, monitoring and general management (blood pressure, blood glucose, temperature, thromboprophylaxis, antiepileptic treatment, use of steroids). Specific therapeutic interventions consider timing of procedures, clipping and coiling. Complications such as hydrocephalus, vasospasm and delayed ischaemic deficit were covered. We also thought to add recommendations on SAH without aneurysm and on unruptured aneurysms.

CONCLUSION

Ruptured intracranial aneurysm with a high rate of subsequent complications is a serious disease needing prompt treatment in centres having high quality of experience of treatment for these patients. These guidelines provide practical, evidence-based advice for the management of patients with intracranial aneurysm with or without rupture. Applying these measures can improve the prognosis of SAH.

Subarachnoid hemorrhage in Kashmir: Causes, risk factors, and outcome

Context:

Kashmir, a snow bound and mountain locked valley, is populated by about 7 million ethnic and non-migratory Kashmiris who have specific dietary and social habits than rest of the world. The neurological disorders are common in Kashmiri population.

Aims:

To study the prevalence and outcome of spontaneous intracranial subarachnoid hemorrhage (SAH) in Kashmir compared withother parts of the world.

Settings and Design:

A retrospective and hospital based study from 1982 to 2010 in the single and only Neurosurgical Centre of the State of Jammu and Kashmir.

Materials and Methods:

A hospital based study, in which, information concerning all Kashmiri patients was collected from the case sheets, patient files, discharge certificates, death certificates, and telephonic conversations with the help of Medical Records Department and Central Admission Register of Sher–i-Kashmir Institute of Medical Sciences, Kashmir India.

Statistical Analysis:

Analysis of variance and students T-test were used at occasions.

Results:

Incidence of SAH in Kashmiris is about 13/100,000 persons per year. SAH comprises 31.02% of total strokes and aneurysmal ruptures are cause of 54.35% SAHs. The female suffers 1.78 times more than the male. Total mortality of 36.60% was recorded against a good recovery of 14.99%. The familial SAHs and multiple aneurysms were also common. Intra-operative finding of larger aneurysmal size than recorded on pre-operative computed tomography (CT) angiogram of same patients was noteworthy. In 493 patients of SAH, the angiography revealed 705 aneurysms.

Conclusion:

Spontaneous intracranial subarachnoid hemorrhage, due to aneurysmal rupture, is common in Kashmir, with worst outcome. Food habits like “salt-tea twice a day”, group-smoking of wet tobacco like “Jejeer”, winter season, female gender, hypertension, and inhalation of “Kangri” smoke are special risk factorsof SAH, in Kashmiris. The plain CT brain and CT angiography are best diagnostic tools. The preventive measures for aneurysmal formation and rupture seems most promising management of future. The detachable endovascular aneurysmal occupying video assisted micro-camera capsules or plugs may be future treatment.

Risk of cardiovascular events and death in the life after aneurysmal subarachnoid haemorrhage: a nationwide study

BACKGROUND AND AIM

The increased mortality rates of survivors of aneurysmal subarachnoid haemorrhage have been attributed to an increased risk of cardiovascular events in a registry study in Sweden. Swedish registries have however not been validated for subarachnoid haemorrhage and Scandinavian incidences of cardiovascular disease differ from that in Western European countries. We assessed risks of vascular disease and death in subarachnoid haemorrhage survivors in the Netherlands.

METHODS

From the Dutch hospital discharge register, we identified all patients with subarachnoid haemorrhage admission between 1997 and 2008. We determined the accuracy of coding of the diagnosis subarachnoid haemorrhage for patients admitted to our centre. Conditional on survival of three-months after the subarachnoid haemorrhage, we calculated standardized incidence and mortality ratios for fatal or nonfatal vascular diseases, vascular death, and all-cause death. Cumulative risks were estimated with survival analysis.

RESULTS

The diagnosis of nontraumatic subarachnoid haemorrhage was correct in 95·4% of 1472 patients. Of 11,263 admitted subarachnoid haemorrhage patients, 6999 survived more than three-months. During follow-up (mean 5·1 years), 874 (12·5%) died. The risks of death were 3·3% within one-year, 11·3% within five-years, and 21·5% within 10 years. The standardized mortality ratio was 3·4 (95% confidence interval: 3·1 to 3·7) for vascular death and 2·2 (95% confidence interval: 2·1 to 2·3) for all-cause death. The standardized incidence ratio for fatal or nonfatal vascular diseases was 2·7 (95% confidence interval: 2·6 to 2·8).

CONCLUSIONS

Dutch hospital discharge and cause of death registries are a valid source of data for subarachnoid haemorrhage, and show that the increased mortality rate in subarachnoid haemorrhage survivors is explained by increased risks for vascular diseases and death.

Risk factors for aneurysmal subarachnoid hemorrhage - BMI and serum lipids: 11-year follow-up of the HUNT and the Tromsø Study in Norway

OBJECTIVES

Life-style factors have been associated with the risk for aneurysmal subarachnoid hemorrhage (aSAH), but it is not clear whether body mass index (BMI) and serum lipids are associated with risk. We prospectively assessed these associations in two large population studies.

METHODS

A total of 65,526 participants in the Nord-Trøndelag Health Study (1995-1997) and 26,882 participants in the Tromsø Study (1994-1995) were included. Studies included measurements of body weight and height, serum lipids, and self-administered questionnaires. Participants who experienced aSAH were identified, and hazard ratios (HRs) were estimated using Cox regression analysis.

RESULTS

During 11 years of follow-up, aSAH was diagnosed in 122 participants. Overweight (BMI 25-29.9) was negatively associated with the risk of aSAH (HR 0.7, 95% CI 0.4-1.0). There was no over all association of total serum cholesterol, HDL cholesterol, or triglycerides with the risk of aSAH, but in participants younger than 50 years, HDL cholesterol was inversely associated with the risk (HR per standard deviation increase 0.6, 95% CI 0.4-0.9).

CONCLUSIONS

Overweight may be associated with reduced risk of aSAH, but there was no over all association of total serum cholesterol, HDL cholesterol, or triglycerides with the risk of aSAH in this prospective study.

Osteogenesis imperfecta, multiple intra-abdominal arterial dissections and a ruptured dissecting-type intracranial aneurysm

We describe an adult patient with a ruptured dissecting-type superior cerebellar artery aneurysm and known osteogenesis imperfecta. He was successfully treated with coil embolization and intentional parent vessel sacrifice. During his hospital admission, he also suffered from abdominal distension. An incidental note was made of multiple intra-abdominal arterial dissections. These were managed conservatively. We review the rare association of osteogenesis imperfecta and intracranial aneurysms, as well as discuss management implications.

[Unruptured intracranial aneurysms]

The incidental discovery of an asymptomatic intracranial arterial aneurysm is no longer uncommon. It can change a person's life. Decision-making should be guided by a thorough comparison of the risks associated with the natural course and with microsurgical or endovascular intervention. At present this comparison will favor a conservative approach in the majority of patients, especially in those with small aneurysms or who are over 50 years old.

Trends in incidence and in short term survival following a subarachnoid haemorrhage in Scotland, 1986-2005: a retrospective cohort study

Background

To examine age and sex specific incidence and 30 day case fatality for subarachnoid haemorrhage (SAH) in Scotland over a 20 year period.

Methods

A retrospective cohort study using routine hospital discharge data linked to death records.

Results

Between 1986 and 2005, 12,056 individuals experienced an incident SAH. Of these 10,113 (84%) survived to reach hospital. Overall age-standardised incidence rates were greater in women than men and remained relatively stable over the study period. In 2005, incidence in women was 12.8 (95% CI 11.5 to 14.2) and in men 7.9 (95% CI 6.9 to 9.1). 30 day case fatality in individuals hospitalised with SAH declined substantially, falling from 30.0% in men and 33.9% in women in 1986-1990 to 24.5% in men and 29.1% in women in 2001-2005. For both men and women, the largest reductions were observed in those aged between 40 to 59 years. After adjustment for age, socio-economic status and co-morbidity, the odds of death at 30 days in 2005 compared to odds of death in 1986 was 0.64 (0.54 to 0.76), p < 0.001 for those below 70 years, and 1.14 (0.83 to 1.56), p = 0.4 in those 70 years and above.

Conclusions

Incidence rates for SAH remained stable between 1986 and 2005 suggesting that a better understanding of SAH risk factors and their reduction is needed. 30 day case fatality rates have declined substantially, particularly in middle-age. However, they remain high and it is important to ensure that this is not due to under-diagnosis or under-treatment.

Design of the China Epidemiology Research in Subarachnoid Haemorrhage (CHERISH) Study

Rationale

Limited epidemiological data exist on subarachnoid haemorrhage (SAH) in China. Effective prevention requires knowledge of the rates and risk factors for SAH the most lethal type of stroke that most often affects younger adults. We report the methods and the initial experience of a new study to address this deficiency.

Aims

To determine the incidence, risk factors, management and outcomes of SAH.

Design

The CHina Epidemiology Research In Subarachnoid Haemorrhage (CHERISH) is a prospective, population-based, case–control study in a defined region (study population 1.7 million) of the city of Baotou in Inner Mongolia, China.

Methods

Cases of spontaneous SAH are identified using standard definitions through prospective surveillance of all major acute care hospitals with neurology/neurosurgery facilities, small hospitals/clinics, and the single city crematorium over a 2-year period. Verbal autopsy procedures are used to ascertain the probable causes of deaths outside of hospital. For each case, two nonrelative controls without SAH are matched by age (5-year strata), gender, and district of residence. Data are collected on socio-demography, lifestyle factors, and medical history, and blood is taken for the extraction and storage of DNA. Details of the clinical features, presentation, and management of SAH are obtained from cases, and survivors provide details on health care utilisation, physical function, health-related quality of life, and complications, at 6-months.

Study outcomes

The primary outcomes are overall, age- and gender-specific incidence, relative (odds ratios) and population-attributable risks for defined exposures, and 28-day and 6-month case fatality ratios and other outcomes.

Conclusions

Preliminary experience confirms the completeness of the surveillance methods, with no clear missed out-of-hospital cases of SAH with sudden death, and of high participation and reliable data collection procedures. CHERISH is well placed to provide reliable estimates of the burden of SAH in China.

Genome-wide association analysis of copy number variations in subarachnoid aneurysmal hemorrhage

Subarachnoid aneurysmal hemorrhage (SAH) due to cerebral aneurysm rupture is a very serious disease resulting in high mortality rate. It has been known that genetic factors are involved in the risk of SAH. A recent breakthrough in genomic variation called copy number variation (CNV) has been revealed to be involved in risks of human diseases. In this study, we hypothesized that CNVs can predict the risk of SAH. We used the Illumina HumanHap300 BeadChip (317 503 markers) to genotype 497 individuals in a Japanese population. Furthermore, individual CNVs were identified using signal and allelic intensities. The genetic effect of CNV on the risk of SAH was evaluated using multivariate logistic regression controlling for age and gender in 187 common CNV regions (frequency >1%). From a total of 4574 individual CNVs identified in this study (9.7 CNVs per individual), we were able to discover 1644 unique CNV regions containing 1232 genes. The identified variations were validated using visual examination of the genoplot image, overlapping analysis with the Database of Genomic Variants (73.2%), CNVpartition (72.4%) and quantitative PCR. Interestingly, two CNV regions, chr4:153210505-153212191 (deletion, 4q31.3, P=0.0005, P(corr) (corrected P-value)=0.04) and chr10:6265006-6267388 (duplication, 10p15.1, P=0.0006, P(corr)=0.05), were significantly associated with the risk of SAH after multiple testing corrections. Our results suggest that the newly identified CNV regions may contribute to SAH disease susceptibility.