Background and ObjectivesScreening for unruptured intracranial aneurysms (UIAs) is effective for first-degree relatives(FDRs) of patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether... Show moreBackground and ObjectivesScreening for unruptured intracranial aneurysms (UIAs) is effective for first-degree relatives(FDRs) of patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether screening isalso effective for FDRs of patients with UIA is unknown. We determined the yield of screening insuch FDRs, assessed rupture risk and treatment decisions of aneurysms that were found, iden-tified potential high-risk subgroups, and studied the effects of screening on quality of life (QoL).MethodsIn this prospective cohort study, we included FDRs, aged 20–70 years, of patients with UIAwithout a family history of aSAH who visited the Neurology outpatient clinic in 1 of 3 partici-pating tertiary referral centers in the Netherlands. FDRs were screened for UIA with magneticresonance angiography between 2017 and 2021. We determined UIA prevalence and developed aprediction model for UIA risk at screening using multivariable logistic regression. QoL wasevaluated with questionnaires 6 times during the first year after screening and assessed with alinear mixed-effects model.ResultsWe detected 24 UIAs in 23 of 461 screened FDRs, resulting in a 5.0% prevalence (95% CI3.2–7.4). The median aneurysm size was 3 mm (interquartile range [IQR] 2–4 mm), and themedian 5-year rupture risk assessed with the PHASES score was 0.7% (IQR 0.4%–0.9%). AllUIAs received follow-up imaging, and none were treated preventively. After a median follow-up of24 months (IQR 13–38 months), no UIA had changed. Predicted UIA risk at screening rangedbetween 2.3% and 14.7% with the highest risk in FDRs who smoke and have excessive alcoholconsumption (c-statistic: 0.76; 95% CI 0.65–0.88). At all survey moments, health-related QoLand emotional functioning were comparable with those in a reference group from the generalpopulation. One FDR with a positive screening result expressed regret about screening.DiscussionBased on the current data, we do not advise screening FDRs of patients with UIA becauseall identified UIAs had a low rupture risk. We observed no negative effect of screening on QoL. Alonger follow-up should determine the risk of aneurysm growth requiring preventive treatment. Show less
Background Prediction models for risk of cardiovascular events generally do not include young adults, and cardiovascular risk factors differ between women and men. Therefore, this study aimed to... Show moreBackground Prediction models for risk of cardiovascular events generally do not include young adults, and cardiovascular risk factors differ between women and men. Therefore, this study aimed to develop prediction models for first-ever cardiovascular event risk in men and women aged 30 to 49 years.Methods and Results We included patients aged 30 to 49 years without cardiovascular disease from a Dutch routine care database. Outcome was defined as first-ever cardiovascular event. Our reference models were sex-specific Cox proportional hazards models based on traditional cardiovascular predictors, which we compared with models using 2 predictor subsets with the 20 or 50 most important predictors based on the Cox elastic net model regularization coefficients. We assessed the C-index and calibration curve slopes at 10 years of follow-up. We stratified our analyses based on 30- to 39-year and 40- to 49-year age groups at baseline. We included 542 141 patients (mean age 39.7, 51% women). During follow-up, 10 767 cardiovascular events occurred. Discrimination of reference models including traditional cardiovascular predictors was moderate (women: C-index, 0.648 [95% CI, 0.645-0.652]; men: C-index, 0.661 [95%CI, 0.658-0.664]). In women and men, the Cox proportional hazard models including 50 most important predictors resulted in an increase in C-index (0.030 and 0.012, respectively), and a net correct reclassification of 3.7% of the events in women and 1.2% in men compared with the reference model.Conclusions Sex-specific electronic health record-derived prediction models for first-ever cardiovascular events in the general population aged <50 years have moderate discriminatory performance. Data-driven predictor selection leads to identification of nontraditional cardiovascular predictors, which modestly increase performance of models. Show less
BackgroundPrediction models for risk of cardiovascular events generally do not include young adults, and cardiovascular risk factors differ between women and men. Therefore, this study aimed to... Show moreBackgroundPrediction models for risk of cardiovascular events generally do not include young adults, and cardiovascular risk factors differ between women and men. Therefore, this study aimed to develop prediction models for first‐ever cardiovascular event risk in men and women aged 30 to 49 years.Methods and ResultsWe included patients aged 30 to 49 years without cardiovascular disease from a Dutch routine care database. Outcome was defined as first‐ever cardiovascular event. Our reference models were sex‐specific Cox proportional hazards models based on traditional cardiovascular predictors, which we compared with models using 2 predictor subsets with the 20 or 50 most important predictors based on the Cox elastic net model regularization coefficients. We assessed the C‐index and calibration curve slopes at 10 years of follow‐up. We stratified our analyses based on 30‐ to 39‐year and 40‐ to 49‐year age groups at baseline. We included 542 141 patients (mean age 39.7, 51% women). During follow‐up, 10 767 cardiovascular events occurred. Discrimination of reference models including traditional cardiovascular predictors was moderate (women: C‐index, 0.648 [95% CI, 0.645–0.652]; men: C‐index, 0.661 [95%CI, 0.658–0.664]). In women and men, the Cox proportional hazard models including 50 most important predictors resulted in an increase in C‐index (0.030 and 0.012, respectively), and a net correct reclassification of 3.7% of the events in women and 1.2% in men compared with the reference model.ConclusionsSex‐specific electronic health record‐derived prediction models for first‐ever cardiovascular events in the general population aged <50 years have moderate discriminatory performance. Data‐driven predictor selection leads to identification of nontraditional cardiovascular predictors, which modestly increase performance of models. Show less
Background:Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and... Show moreBackground:Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and therefore have potential to be used for genetic risk prediction. We constructed a genetic risk score to (1) predict ASAH incidence and IA presence (combined set of unruptured IA and ASAH) and (2) assess its association with patient characteristics. Methods:A genetic risk score incorporating genetic association data for IA and 17 traits related to IA (so-called metaGRS) was created using 1161 IA cases and 407 392 controls from the UK Biobank population study. The metaGRS was validated in combination with risk factors blood pressure, sex, and smoking in 828 IA cases and 68 568 controls from the Nordic HUNT population study. Furthermore, we assessed association between the metaGRS and patient characteristics in a cohort of 5560 IA patients. Results:Per SD increase of metaGRS, the hazard ratio for ASAH incidence was 1.34 (95% CI, 1.20-1.51) and the odds ratio for IA presence 1.09 (95% CI, 1.01-1.18). Upon including the metaGRS on top of clinical risk factors, the concordance index to predict ASAH hazard increased from 0.63 (95% CI, 0.59-0.67) to 0.65 (95% CI, 0.62-0.69), while prediction of IA presence did not improve. The metaGRS was statistically significantly associated with age at ASAH (beta=-4.82x10(-3) per year [95% CI, -6.49x10(-3) to -3.14x10(-3)]; P=1.82x10(-8)), and location of IA at the internal carotid artery (odds ratio=0.92 [95% CI, 0.86-0.98]; P=0.0041). Conclusions:The metaGRS was predictive of ASAH incidence, although with limited added value over clinical risk factors. The metaGRS was not predictive of IA presence. Therefore, we do not recommend using this metaGRS in daily clinical care. Genetic risk does partly explain the clinical heterogeneity of IA warranting prioritization of clinical heterogeneity in future genetic prediction studies of IA and ASAH. Show less
Background: Young patients with aneurysmal subarachnoid hemorrhage (aSAH) and a history of migraine may have an increased risk of delayed cerebral ischemia. We investigated this potential... Show moreBackground: Young patients with aneurysmal subarachnoid hemorrhage (aSAH) and a history of migraine may have an increased risk of delayed cerebral ischemia. We investigated this potential association in a prospective cohort of aSAH patients under 50 years of age. Methods: In our prospective cohort study, we included patients with aSAH under 50 years of age from 3 hospitals in the Netherlands. We assessed lifetime migraine history with a short screener. Delayed cerebral ischemia was defined as neurological deterioration lasting >1 hour not attributable to other causes by diagnostic workup. Adjustments were made for possible confounders in multivariable Cox regression analyses, and adjusted hazard ratios were calculated. Results: We included 236 young aSAH patients (mean age, 41 years; 64% women) of whom 44 (19%) had a history of migraine (16 with aura). Patients with aSAH and a history of migraine were not at increased risk of developing delayed cerebral ischemia compared with patients without migraine (25% versus 20%; adjusted hazard ratio, 1.16 [95% CI, 0.57-2.35]). Additionally, no increased risk was found in migraine patients with aura (adjusted hazard ratio, 0.85 [95% CI, 0.30-2.44]) or in women (adjusted hazard ratio, 1.24 [95% CI, 0.58-2.68]). Conclusions: Patients with aSAH under the age of 50 years with a history of migraine are not at increased risk of delayed cerebral ischemia. Show less
Background and Purpose: In previous studies, women had a higher risk of rupture of intracranial aneurysms than men, but female sex was not an independent risk factor. This may be explained by a... Show moreBackground and Purpose: In previous studies, women had a higher risk of rupture of intracranial aneurysms than men, but female sex was not an independent risk factor. This may be explained by a higher prevalence of patient- or aneurysm-related risk factors for rupture in women than in men or by insufficient power of previous studies. We assessed sex differences in rupture rate taking into account other patient- and aneurysm-related risk factors for aneurysmal rupture. Methods: We searched Embase and Pubmed for articles published until December 1, 2020. Cohorts with available individual patient data were included in our meta-analysis. We compared rupture rates of women versus men using a Cox proportional hazard regression model adjusted for the PHASES score (Population, Hypertension, Age, Size of Aneurysm, Earlier Subarachnoid Hemorrhage From Another Aneurysm, Site of Aneurysm), smoking, and a positive family history of aneurysmal subarachnoid hemorrhage. Results: We pooled individual patient data from 9 cohorts totaling 9940 patients (6555 women, 66%) with 12 193 unruptured intracranial aneurysms, and 24 357 person-years follow-up. Rupture occurred in 163 women (rupture rate 1.04%/person-years [95% CI, 0.89-1.21]) and 63 men (rupture rate 0.74%/person-years [95% CI, 0.58-0.94]). Women were older (61.9 versus 59.5 years), were less often smokers (20% versus 44%), more often had internal carotid artery aneurysms (24% versus 17%), and larger sized aneurysms (>= 7 mm, 24% versus 23%) than men. The unadjusted women-to-men hazard ratio was 1.43 (95% CI, 1.07-1.93) and the adjusted women/men ratio was 1.39 (95% CI, 1.02-1.90). Conclusions: Women have a higher risk of aneurysmal rupture than men and this sex difference is not explained by differences in patient- and aneurysm-related risk factors for aneurysmal rupture. Future studies should focus on the factors explaining the higher risk of aneurysmal rupture in women. Show less
Background and Purpose:In previous studies, women had a higher risk of rupture of intracranial aneurysms than men, but female sex was not an independent risk factor. This may be explained by a... Show moreBackground and Purpose:In previous studies, women had a higher risk of rupture of intracranial aneurysms than men, but female sex was not an independent risk factor. This may be explained by a higher prevalence of patient- or aneurysm-related risk factors for rupture in women than in men or by insufficient power of previous studies. We assessed sex differences in rupture rate taking into account other patient- and aneurysm-related risk factors for aneurysmal rupture.Methods:We searched Embase and Pubmed for articles published until December 1, 2020. Cohorts with available individual patient data were included in our meta-analysis. We compared rupture rates of women versus men using a Cox proportional hazard regression model adjusted for the PHASES score (Population, Hypertension, Age, Size of Aneurysm, Earlier Subarachnoid Hemorrhage From Another Aneurysm, Site of Aneurysm), smoking, and a positive family history of aneurysmal subarachnoid hemorrhage.Results:We pooled individual patient data from 9 cohorts totaling 9940 patients (6555 women, 66%) with 12 193 unruptured intracranial aneurysms, and 24 357 person-years follow-up. Rupture occurred in 163 women (rupture rate 1.04%/person-years [95% CI, 0.89–1.21]) and 63 men (rupture rate 0.74%/person-years [95% CI, 0.58–0.94]). Women were older (61.9 versus 59.5 years), were less often smokers (20% versus 44%), more often had internal carotid artery aneurysms (24% versus 17%), and larger sized aneurysms (≥7 mm, 24% versus 23%) than men. The unadjusted women-to-men hazard ratio was 1.43 (95% CI, 1.07–1.93) and the adjusted women/men ratio was 1.39 (95% CI, 1.02–1.90).Conclusions:Women have a higher risk of aneurysmal rupture than men and this sex difference is not explained by differences in patient- and aneurysm-related risk factors for aneurysmal rupture. Future studies should focus on the factors explaining the higher risk of aneurysmal rupture in women. Show less
Ocak, G.; Khairoun, M.; Khairoun, O.; Bos, W.J.W.; Fu, E.L.; Cramer, M.J.; ... ; UCC-SMART Study Grp 2022
Background: Chronic kidney disease (CKD) and atrial fibrillation (AF) are both risk factors for bleeding, stroke and mortality. The aim of our study was to investigate the interaction between CKD... Show moreBackground: Chronic kidney disease (CKD) and atrial fibrillation (AF) are both risk factors for bleeding, stroke and mortality. The aim of our study was to investigate the interaction between CKD and atrial fibrillation and outcomes. Methods: We included 12,394 subjects referred to the University Medical Center Utrecht (the Netherlands) from September 1996 to February 2018 for an out-patient visit (Utrecht Cardiovascular Cohort Second Manifestation of Arterial disease cohort). Hazard ratios (HRs) with 95% confidence intervals (CIs) for bleeding, ischemic stroke or mortality were calculated with Cox proportional hazard analyses. Presence of interaction between AF and CKD was examined by calculating the relative excess risk due to interaction (RERI), the attributable proportion (AP) due to interaction and the synergy index (S). Results: Of the 12,394 patients, 699 patients had AF, 2,752 patients had CKD and 325 patients had both AF and CKD. Patients with both CKD and AF had a 3.0-fold (95% CI 2.0-4.4) increased risk for bleeding, a 4.2-fold (95% CI 3.0-6.0) increased ischemic stroke risk and a 2.2-fold (95% CI 1.9-2.6) increased mortality risk after adjustment as compared with subjects without atrial fibrillation and CKD. We did not find interaction between AF and CKD for bleeding and mortality. However, we found interaction between AF and CKD for ischemic stroke risk (RERI 1.88 (95% CI 0.31-3.46), AP 0.45 (95% CI 0.17-0.72) and S 2.40 (95% CI 1.08-5.32)). Conclusion: AF and CKD are both associated with bleeding, ischemic stroke and mortality. There is a positive interaction between AF and CKD for ischemic stroke risk, but not for bleeding or mortality. Show less
Background and Objectives We combined individual patient data (IPD) from prospective cohorts of patients with unruptured intracranial aneurysms (UIAs) to assess to what extent patients with... Show moreBackground and Objectives We combined individual patient data (IPD) from prospective cohorts of patients with unruptured intracranial aneurysms (UIAs) to assess to what extent patients with familial UIA have a higher rupture risk than those with sporadic UIA. Methods For this IPD meta-analysis, we performed an Embase and PubMed search for studies published up to December 1, 2020. We included studies that (1) had a prospective study design; (2) included 50 or more patients with UIA; (3) studied the natural course of UIA and risk factors for aneurysm rupture including family history for aneurysmal subarachnoid haemorrhage and UIA; and (4) had aneurysm rupture as an outcome. Cohorts with available IPD were included. All studies included patients with newly diagnosed UIA visiting one of the study centers. The primary outcome was aneurysmal rupture. Patients with polycystic kidney disease and moyamoya disease were excluded. We compared rupture rates of familial vs sporadic UIA using a Cox proportional hazard regression model adjusted for PHASES score and smoking. We performed 2 analyses: (1) only studies defining first-degree relatives as parents, children, and siblings and (2) all studies, including those in which first-degree relatives are defined as only parents and children, but not siblings. Results We pooled IPD from 8 cohorts with a low and moderate risk of bias. First-degree relatives were defined as parents, siblings, and children in 6 cohorts (29% Dutch, 55% Finnish, 15% Japanese), totaling 2,297 patients (17% familial, 399 patients) with 3,089 UIAs and 7,301 person-years follow-up. Rupture occurred in 10 familial cases (rupture rate: 0.89%/person-year; 95% confidence interval [CI] 0.45-1.59) and 41 sporadic cases (0.66%/person-year; 95% CI 0.48-0.89); adjusted hazard ratio (HR) for familial cases 2.56 (95% CI 1.18-5.56). After adding the 2 cohorts excluding siblings as first-degree relatives, resulting in 9,511 patients, the adjusted HR was 1.44 (95% CI 0.86-2.40). Discussion The risk of rupture of UIA is 2.5 times higher, with a range from a 1.2 to 5 times higher risk, in familial than in sporadic UIA. When assessing the risk of rupture in UIA, family history should be taken into account. Show less
Background: An increased risk of stroke in patients with migraine has been primarily found for women. The sex-dependent mechanisms underlying the migraine-stroke association, however, remain... Show moreBackground: An increased risk of stroke in patients with migraine has been primarily found for women. The sex-dependent mechanisms underlying the migraine-stroke association, however, remain unknown. This study aims to explore these sex differences to improve our understanding of pathophysiological mechanisms behind the migraine-stroke association.Methods: We included 2,492 patients with ischemic stroke from the prospective multicenter Dutch Parelsnoer Institute Initiative study, 425 (17%) of whom had a history of migraine. Cardiovascular risk profile, stroke cause (TOAST classification), and outcome [modified Rankin scale (mRS) at 3 months] were compared with both sexes between patients with and without migraine.Results: A history of migraine was not associated with sex differences in the prevalence of conventional cardiovascular risk factors. Women with migraine had an increased risk of stroke at young age (onset < 50 years) compared with women without migraine (RR: 1.7; 95% CI: 1.3-2.3). Men with migraine tended to have more often stroke in the TOAST category other determined etiology (RR: 1.7; 95% CI: 1.0-2.7) in comparison with men without migraine, whereas this increase was not found in women with migraine. Stroke outcome was similar for women with or without migraine (mRS >= 3 RR 1.1; 95% CI 0.7-1.5), whereas men seemed to have a higher risk of poor outcome compared with their counterparts without migraine (mRS >= 3 RR: 1.5; 95% CI: 1.0-2.1).Conclusion: Our results indicate possible sex differences in the pathophysiology underlying the migraine-stroke association, which are unrelated to conventional cardiovascular risk factors. Further research in larger cohorts is needed to validate these findings. Show less
Background and Purpose: Delayed cerebral ischemia (DCI) is a major contributor to the high morbidity in patients with aneurysmal subarachnoid hemorrhage (aSAH). Spreading depolarizations may play a... Show moreBackground and Purpose: Delayed cerebral ischemia (DCI) is a major contributor to the high morbidity in patients with aneurysmal subarachnoid hemorrhage (aSAH). Spreading depolarizations may play a role in DCI pathophysiology. Because patients with migraine are probably more susceptible to spreading depolarizations, we investigated whether patients with aneurysmal subarachnoid hemorrhage with migraine are at increased risk for DCI. Methods: We included patients with aneurysmal subarachnoid hemorrhage from 3 hospitals in the Netherlands. We assessed lifetime migraine history with a short screener. DCI was defined as neurological deterioration lasting >1 hour not attributable to other causes by diagnostic work-up. Adjustments were made for possible confounders in multivariable Cox regression analyses and adjusted hazard ratios (aHR) were calculated. We assessed the interaction effects of age and sex. Results: We included 582 patients (mean age 57 years, 71% women) mostly with mild to moderate aneurysmal subarachnoid hemorrhage of whom 108 (19%) had a history of migraine (57 with aura). Patients with migraine were not at increased risk of developing DCI compared with patients without migraine (22% versus 24%, aHR, 0.89 [95% CI, 0.56-1.43]). Additionally, no increased risk was found in patients with migraine with possible aura (aHR, 0.74 [95% CI, 0.39-1.43]), in women (aHR, 0.88 [95% CI, 0.53-1.45],P-interaction=0.859), or in young patients aged <50 years (aHR, 1.59 [95% CI, 0.72-3.49]), although numbers in these subgroups were limited. We found an interaction between migraine and age with an increased risk of DCI among young patients with migraine (P-interaction=0.075). Conclusions: Patients with migraine are in general not at increased risk of DCI. Future studies should focus in particular on young SAH patients, in whom there might be an association between migraine history and development of DCI. Show less
Background: A cardiac origin in ischemic stroke is more frequent than previously assumed, but it is not clear which patients benefit from cardiac work-up if obvious cardiac pathology is absent. We... Show moreBackground: A cardiac origin in ischemic stroke is more frequent than previously assumed, but it is not clear which patients benefit from cardiac work-up if obvious cardiac pathology is absent. We hypothesized that thromboembolic stroke with a cardiac source occurs more frequently in the posterior circulation compared with thromboembolic stroke of another etiology. Methods: We performed a multicenter observational study in 3,311 consecutive patients with ischemic stroke who were enrolled in an ongoing prospective stroke registry of 8 University hospitals between September 2009 and November 2014 in The Netherlands. In this initiative, the so-called Parelsnoer Institute-Cerebrovascular Accident Study Group, clinical data, imaging, and biomaterials of patients with stroke are prospectively and uniformly collected. We compared the proportions of posterior stroke location in patients with a cardiac stroke source with those with another stroke etiology and calculated risk ratios (RR) with corresponding 95% CI with Poisson regression analyses. To assess which patient or disease characteristics were most strongly associated with a cardiac etiology in patients with ischemic stroke, we performed a stepwise backward regression analysis. Results: For the primary aim, 1,428 patients were eligible for analyses. The proportion of patients with a posterior stroke location among patients with a cardiac origin of their stroke (28%) did not differ statistically significant to those with another origin (25%), age and sex adjusted RR 1.16; 95% CI 0.96-1.41. For the secondary aim, 1,955 patients were eligible for analyses. No recent history of smoking, no hyperlipidemia, coronary artery disease, a higher age, and a higher National Institutes of Health Stroke Scale (NIHSS) score were associated with a cardiac etiology of ischemic stroke. Conclusions: We could not confirm our hypothesis that thromboembolic stroke localized in the posterior circulation is associated with a cardioembolic source of ischemic stroke, and therefore posterior stroke localization on itself does not necessitate additional cardiac examination. The lack of determinants of atherosclerosis, for example, no recent history of smoking and no hyperlipidemia, coronary artery disease, a higher age, and a higher NIHSS score are stronger risk factors for a cardiac source of ischemic stroke. Show less
We investigated whether genes influencing coagulation are associated with the occurrence of aneurysmal subarachnoid hemorrhage (SAH) and with secondary cerebral ischemia and rebleeding in patients... Show moreWe investigated whether genes influencing coagulation are associated with the occurrence of aneurysmal subarachnoid hemorrhage (SAH) and with secondary cerebral ischemia and rebleeding in patients with aneurysmal SAH. Genotyping for factor V Leiden (G1691A), prothrombin G20210A, methylenetetetrahydrofolate reductase (MTHFR) C677T, factor XIII subunit A Val34Leu, Tyr204Phe and Pro564Leu, and factor XIII subunit B His95Arg was performed in 208 patients with aneurysmal SAH and in 925 controls. Secondary cerebral ischemia occurred in 49 (24%) patients and rebleeding in 28 (14%) during their clinical course of 3 months after the aneurysmal SAH. The risk of aneurysmal SAH was assessed as odds ratio (OR) with 95% confidence interval (95% CI). The risk of secondary cerebral ischemia and rebleeding was assessed as hazard ratio (HR) with 95% CI using Cox regression. Carriers of the subunit B His95Arg factor XIII polymorphism had an increased risk of aneurysmal SAH with 23% of the patients homozygous or heterozygous for the variant allele compared to 17% of control subjects (OR 1.5, 95% CI 1.0-2.2). For the remaining genetic variants no effect on the risk of aneurysmal SAH could be demonstrated. A clear relation with the risk of secondary cerebral ischemia and of rebleeding could not be established for any of the genetic variants. We found that aneurysmal SAH patients are more often carriers of the subunit B His95Arg factor XIII polymorphism compared to controls. This suggests that carriers of the subunit B His95Arg factor XIII polymorphism have an increased risk of aneurysmal SAH. Larger studies should confirm our results. As aneurysmal SAH patients who died soon after admission could not be included in the present study, our results only apply to a population of patients who survived the initial hours after the hemorrhage. For the other studied genetic factors involved in coagulation, no association with the occurrence of aneurysmal SAH or with the occurrence of secondary cerebral ischemia or rebleeding after aneurysmal SAH could be demonstrated. Show less
