Worldwide Incidence of Aneurysmal Subarachnoid Hemorrhage According to Region, Time Period, Blood Pressure, and Smoking Prevalence in the Population: A Systematic Review and Meta-analysis.

Importance: Subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms is a subset of stroke with high fatality and morbidity. Better understanding of a change in incidence over time and of factors associated with this change could facilitate primary prevention. Objective: To assess worldwide SAH incidence according to region, age, sex, time period, blood pressure, and smoking prevalence. Data Sources: We searched PubMed, Web of Science, and Embase for studies on SAH incidence published between January 1960 and March 2017. Worldwide blood pressure and smoking prevalence data were extracted from the Noncommunicable Disease Risk Factor and Global Burden of Disease data sets. Study Selection: Population-based studies with prospective designs representative of the entire study population according to predefined criteria. Data Extraction and Synthesis: Two reviewers independently extracted data according to PRISMA guidelines. Incidence of SAH was calculated per 100 000 person-years, and risk ratios (RRs) including 95% CIs were calculated with multivariable random-effects binomial regression. The association of SAH incidence with blood pressure and smoking prevalence was assessed with linear regression. Main Outcomes and Measures: Incidence of SAH. Results: A total of 75 studies from 32 countries were included. These studies comprised 8176 patients with SAH were studied over 67 746 051 person-years. Overall crude SAH incidence across all midyears was 7.9 (95% CI, 6.9-9.0) per 100 000 person-years; the RR for women was 1.3 (95% CI, 0.98-1.7). Compared with men aged 45 to 54 years, the RR in Japanese women older than 75 years was 2.5 (95% CI, 1.8-3.4) and in European women older than 75 years was 1.5 (95% CI, 0.9-2.5). Global SAH incidence declined from 10.2 (95% CI, 8.4-12.5) per 100 000 person-years in 1980 to 6.1 (95% CI, 4.9-7.5) in 2010 or by 1.7% (95% CI, 0.6-2.8) annually between 1955 and 2014. Incidence of SAH declined between 1980 and 2010 by 40.6% in Europe, 46.2% in Asia, and 14.0% in North America and increased by 59.1% in Japan. The global SAH incidence declined with every millimeter of mercury decrease in systolic blood pressure by 7.1% (95% CI, 5.8-8.4) and with every percentage decrease in smoking prevalence by 2.4% (95% CI, 1.6-3.3). Conclusions and Relevance: Worldwide SAH incidence and its decline show large regional differences and parallel the decrease in blood pressure and smoking prevalence. Understanding determinants for regional differences and further reducing blood pressure and smoking prevalence may yield a diminished SAH burden.

A systematic investigation of navigation impairment in chronic stroke patients: Evidence for three distinct types.

OBJECTIVE: In a recent systematic review, Claessen and van der Ham (2017) have analyzed the types of navigation impairment in the single-case study literature. Three dissociable types related to landmarks, locations, and paths were identified. This recent model as well as previous models of navigation impairment have never been verified in a systematic manner. The aim of the current study was thus to investigate the prevalence of landmark-based, location-based, and path-based navigation impairment in a large sample of stroke patients. METHOD: Navigation ability of 77 stroke patients in the chronic phase and 60 healthy participants was comprehensively evaluated using the Virtual Tübingen test, which contains twelve subtasks addressing various aspects of knowledge about landmarks, locations, and paths based on a newly learned virtual route. Participants also filled out the Wayfinding Questionnaire to allow for making a distinction between stroke patients with and without significant subjective navigation-related complaints. RESULTS: Analysis of responses on the Wayfinding Questionnaire indicated that 33 of the 77 participating stroke patients had significant navigation-related complaints. An examination of their performance on the Virtual Tübingen test established objective evidence for navigation impairment in 27 patients. Both landmark-based and path-based navigation impairment occurred in isolation, while location-based navigation impairment was only found along with the other two types. CONCLUSIONS: The current study provides the first empirical support for the distinction between landmark-based, location-based, and path-based navigation impairment. Future research relying on other assessment instruments of navigation ability might be helpful to further validate this distinction.

The Wayfinding Questionnaire as a Self-report Screening Instrument for Navigation-related Complaints After Stroke: Internal Validity in Healthy Respondents and Chronic Mild Stroke Patients.

OBJECTIVE: In current stroke care, cognitive problems are usually diagnosed in a stepwise manner. More specifically, screening instruments are first applied to support healthcare professionals in deciding whether a second step (an extensive assessment) would be appropriate. None of the existing screening instruments, however, takes navigation ability into account. This is problematic, as navigation impairment after stroke has been shown to be common, more so than previously thought. The Wayfinding Questionnaire (WQ) is therefore presented as a screening instrument for navigation-related complaints after stroke. The internal validity of the WQ was investigated in two samples of participants to establish the final version. METHOD AND RESULTS: In Study 1, the WQ was administered in a representative sample of 356 healthy participants. Its factor structure was investigated using a principal component analysis. This procedure resulted in deletion of four items and revealed a three-factor structure: "Navigation and Orientation," "Spatial Anxiety," and "Distance Estimation". In Study 2, a confirmatory analysis was performed to directly verify the factor structure as obtained in Study 1 based on data of 158 chronic mild stroke patients. Fit indices of the confirmatory analysis indicated acceptable model fit. The reliability of the three subscales was found to be very good in both healthy participants and patients. CONCLUSIONS: These studies allowed us to determine the final version of the WQ. The results indicated that the WQ is an internally valid and reliable instrument that can be interpreted using a three-factor structure in both healthy respondents and chronic mild stroke patients.

A Direct Comparison of Real-World and Virtual Navigation Performance in Chronic Stroke Patients.

OBJECTIVES: An increasing number of studies have presented evidence that various patient groups with acquired brain injury suffer from navigation problems in daily life. This skill is, however, scarcely addressed in current clinical neuropsychological practice and suitable diagnostic instruments are lacking. Real-world navigation tests are limited by geographical location and associated with practical constraints. It was, therefore, investigated whether virtual navigation might serve as a useful alternative. METHODS: To investigate the convergent validity of virtual navigation testing, performance on the Virtual Tubingen test was compared to that on an analogous real-world navigation test in 68 chronic stroke patients. The same eight subtasks, addressing route and survey knowledge aspects, were assessed in both tests. In addition, navigation performance of stroke patients was compared to that of 44 healthy controls. RESULTS: A correlation analysis showed moderate overlap (r = .535) between composite scores of overall real-world and virtual navigation performance in stroke patients. Route knowledge composite scores correlated somewhat stronger (r = .523) than survey knowledge composite scores (r = .442). When comparing group performances, patients obtained lower scores than controls on seven subtasks. Whereas the real-world test was found to be easier than its virtual counterpart, no significant interaction-effects were found between group and environment. CONCLUSIONS: Given moderate overlap of the total scores between the two navigation tests, we conclude that virtual testing of navigation ability is a valid alternative to navigation tests that rely on real-world route exposure.

Early prediction of delayed cerebral ischemia after subarachnoid hemorrhage: development and validation of a practical risk chart.

BACKGROUND AND PURPOSE: To develop and validate a risk chart for prediction of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on admission characteristics. METHODS: For derivation of the risk chart, we studied data from 371 prospectively collected consecutive subarachnoid hemorrhage patients with a confirmed aneurysm admitted between 1999 and 2007. For its validation we similarly studied 255 patients admitted between 2007 and 2009. The predictive value of admission characteristics was tested in logistic regression models with delayed cerebral ischemia-related infarction as primary outcome. Procedure-related infarctions were not included. Performance of the models was tested by discrimination and calibration. On the basis of these models, a risk chart was developed for application in clinical practice. RESULTS: The strongest predictors were clinical condition on admission, amount of blood on computed tomography (both cisternal and intraventricular) and age. A model that combined these 4 predictors had an area under the receiver operating characteristic curve of 0.63 (95% confidence interval, 0.57-0.69). This model improved little by including current smoking and hyperglycemia on admission (area under the receiver operating characteristic curve, 0.65; 95% confidence interval, 0.59-0.71). The risk chart predicted risks of delayed cerebral ischemia-related infarction varying from 12% to 61%. Both low risk (<20% risk) and high risk (>40% risk) were predicted in ≈20% of the patients. Validation confirmed that the discriminative ability was adequate (area under the receiver operating characteristic curve, 0.69; 95% confidence interval, 0.61-0.77). CONCLUSIONS: Absolute risks of delayed cerebral ischemia-related infarction can be reliably estimated by a simple risk chart that includes clinical condition on admission, amount of blood on computed tomography (both cisternal and intraventricular), and age.

Delayed cerebral ischemia after subarachnoid hemorrhage: a systematic review of clinical, laboratory, and radiological predictors.

BACKGROUND AND PURPOSE: Established predictors of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage are large amounts of extravasated blood and poor clinical condition on admission. The predictive value of other factors is uncertain. METHODS: We searched MEDLINE (1960-2012) for clinical, laboratory, and radiological predictors routinely available within 72 hours after subarachnoid hemorrhage. The studies were categorized according to methodological quality. Crude data and effect estimates (odds ratio [OR], hazard ratios, and risk ratio) with 95% CI were extracted, (re-)calculated and pooled if possible. For every potential predictor we assessed all effect estimates on consistency (point estimates in equal direction) and clinical relevance (size and 95% CI). RESULTS: Fifty-two studies on 33 potential predictors were included. There was strong evidence (≥3 high-quality studies) for a higher risk of delayed cerebral ischemia in smokers (pooled OR, 1.2; 95% CI, 1.1-1.4), and moderate evidence (2 high-quality studies) for an increased risk in patients with hyperglycemia (OR, 3.2; 1.8-5.8 and hazard ratios, 1.7; 1.1-2.5), hydrocephalus (OR, 1.3; 1.1-1.5 and OR, 2.6; 1.2-5.5), history of diabetes mellitus (pooled OR, 6.7; 1.7-26), and early systemic inflammatory response syndrome (pooled OR, 2.1; 1.4-3.3). Evidence was limited for increased risk in women (pooled OR, 1.3; 1.1-1.6) and in patients with history of hypertension (pooled OR, 1.5; 1.3-1.7). The evidence on initial loss of consciousness, history of migraine, previous use of selective serotonin reuptake inhibitors, hypomagnesemia, low hemoglobin, or high blood flow on early transcranial Doppler was also limited. CONCLUSIONS: There is strong evidence that smoking is a predictor of delayed cerebral ischemia. For several other potential predictions the evidence is moderate, limited, or inconsistent.

Lupus anticoagulant in patients with subarachnoid haemorrhage.

BACKGROUND: In aneurysmal subarachnoid haemorrhage (SAH), delayed cerebral ischaemia (DCI) is a serious complication that occurs in approximately 30% of patients. Lupus anticoagulant (LAC) is a risk factor for thrombotic events and has been associated with cerebral infarction after SAH. OBJECTIVE: To determine the frequency of LAC in patients with SAH and its association with DCI. METHODS: Patients with aneurysmal SAH from a prospectively collected database between 1998 and 2009 were included. Presence of LAC was detected with dilute Russell's viper venom time reagents. Investigation of the association with DCI was planned in case of an increased prevalence of LAC compared with the general population. RESULTS: Of 511 patients, LAC was detected in only six (1.2%; 95% CI 0.4 to 2.5%). In two of these six patients, DCI was diagnosed. CONCLUSION: No evidence was found that LAC contributes to the development of DCI in patients with aneurysmal SAH.

Diagnosing delayed cerebral ischemia with different CT modalities in patients with subarachnoid hemorrhage with clinical deterioration.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage worsens the prognosis and is difficult to diagnose. We investigated the diagnostic value of noncontrast CT (NCT), CT perfusion (CTP), and CT angiography (CTA) for DCI after clinical deterioration in patients with subarachnoid hemorrhage. METHODS: We prospectively enrolled 42 patients with subarachnoid hemorrhage with clinical deterioration suspect for DCI (new focal deficit or Glasgow Coma Scale decrease >or=2 points) within 21 days after hemorrhage. All patients underwent NCT, CTP, and CTA scans on admission and directly after clinical deterioration. The gold standard was the clinical diagnosis DCI made retrospectively by 2 neurologists who interpreted all clinical data, except CTP and CTA, to rule out other causes for the deterioration. Radiologists interpreted NCT and CTP images for signs of ischemia (NCT) or hypoperfusion (CTP) not localized in the neurosurgical trajectory or around intracerebral hematomas, and CTA images for presence of vasospasm. Diagnostic values for DCI of NCT, CTP, and CTA were assessed by calculating sensitivities, specificities, positive predictive values, and negative predictive values with 95% CIs. RESULTS: In 3 patients with clinical deterioration, imaging failed due to motion artifacts. Of the remaining 39 patients, 25 had DCI and 14 did not. NCT had a sensitivity of 0.56 (95% CI, 0.37 to 0.73), specificity=0.71 (0.57 to 0.77), positive predictive value=0.78 (0.55 to 0.91), negative predictive value=0.48 (0.28 to 0.68); CTP: sensitivity=0.84 (0.65 to 0.94), specificity=0.79 (0.52 to 0.92), positive predictive value=0.88 (0.69 to 0.96), negative predictive value=0.73 (0.48 to 0.89); CTA: sensitivity=0.64 (0.45 to 0.80), specificity=0.50 (0.27 to 0.73), positive predictive value=0.70 (0.49 to 0.84), negative predictive value=0.44 (0.23 to 0.67). CONCLUSIONS: As a diagnostic tool for DCI, qualitative assessment of CTP is overall superior to NCT and CTA and could be useful for fast decision-making and guiding treatment.

Changes in case fatality of aneurysmal subarachnoid haemorrhage over time, according to age, sex, and region: a meta-analysis.

BACKGROUND: In a systematic review, published in 1997, we found that the case fatality of aneurysmal subarachnoid haemorrhage (SAH) decreased during the period 1960-95. Because diagnostic and treatment strategies have improved and new studies from previously non-studied regions have been published since 1995, we did an updated meta-analysis to assess changes in case fatality and morbidity and differences according to age, sex, and region. METHODS: A new search of PubMed with predefined inclusion criteria for case finding and diagnosis identified reports on prospective population-based studies published between January, 1995, and July, 2007. The studies included in the previous systematic review were reassessed with the new inclusion criteria. Changes in case fatality over time and the effect of age and sex were quantified with weighted linear regression. Regional differences were analysed with linear regression analysis, and the regions of interest were subsequently defined as reference regions and compared with the other regions. FINDINGS: 33 studies (23 of which were published in 1995 or later) were included that described 39 study periods. These studies reported on 8739 patients, of whom 7659 [88%] were reported on after 1995. 11 of the studies that were included in the previous review did not meet the current, more stringent, inclusion criteria. The mean age of patients had increased in the period 1973 to 2002 from 52 to 62 years. Case fatality varied from 8.3% to 66.7% between studies and decreased 0.8% per year (95% CI 0.2 to 1.3). The decrease was unchanged after adjustment for sex, but the decrease per year was 0.4% (-0.5 to 1.2) after adjustment for age. Case fatality was 11.8% (3.8 to 19.9) lower in Japan than it was in Europe, the USA, Australia, and New Zealand. The unadjusted decrease in case fatality excluding the data for Japan was 0.6% per year (0.0 to 1.1), a 17% decrease over the three decades. Six studies reported data on case morbidity, but these were insufficient to assess changes over time. INTERPRETATION: Despite an increase in the mean age of patients with SAH, case-fatality rates have decreased by 17% between 1973 and 2002 and show potentially important regional differences. This decrease coincides with the introduction of improved management strategies. FUNDING: Netherlands Organisation for Scientific Research; ZonMw.

Configuration of the circle of Willis, direction of flow, and shape of the aneurysm as risk factors for rupture of intracranial aneurysms.

BACKGROUND: Improved knowledge on risk factors for rupture of intracranial aneurysms may lead to more tailored aneurysm management. We studied whether configuration of the circle of Willis, direction of flow towards the aneurysm, and shape of the aneurysm are risk factors for rupture. METHODS: We reviewed CT angiograms of 126 patients with 75 ruptured and 75 unruptured aneurysms, matched for site of the aneurysm, gender and age of the patient, and year of CT angiogram. For the characteristics studied, we calculated odd ratios (ORs) with corresponding 95% confidence intervals (CIs) for risk of rupture. Configuration of the circle of Willis (incompleteness, asymmetry or dominance) was analyzed on a per site basis. Non-spherical shape was subdivided into elliptical (oval and oblong) and multilobed. In additional analyses, we adjusted for size by means of multivariable logistic regression. RESULTS: Flow straight into the aneurysm (OR 2.0; 95% CI 1.0-4.1) and non-spherical shape (OR 2.8; 95% CI 1.5-5.5) were associated with rupture. Both elliptical shape, with increasing ORs for oval (OR 1.8; 95% CI 0.8-4.0) to oblong shape (OR 6.2; 95% CI 1.9-21), and multilobed shape (OR 4.1; 95% CI 1.2-14) were associated with rupture. These ORs decreased after adjustment for size. Configuration of the circle of Willis was not associated with a strong risk of rupture; moderate risk could not be excluded. CONCLUSION: Direction of flow into the aneurysm and nonspherical (both elliptical and multilobed) shape may contribute to the risk of rupture, but are related to aneurysm size and may warrant more frequent follow-up.