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Concept: Subarachnoid hemorrhage

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Background Stroke is common during the first few weeks after a transient ischemic attack (TIA) or minor ischemic stroke. Combination therapy with clopidogrel and aspirin may provide greater protection against subsequent stroke than aspirin alone. Methods In a randomized, double-blind, placebo-controlled trial conducted at 114 centers in China, we randomly assigned 5170 patients within 24 hours after the onset of minor ischemic stroke or high-risk TIA to combination therapy with clopidogrel and aspirin (clopidogrel at an initial dose of 300 mg, followed by 75 mg per day for 90 days, plus aspirin at a dose of 75 mg per day for the first 21 days) or to placebo plus aspirin (75 mg per day for 90 days). All participants received open-label aspirin at a clinician-determined dose of 75 to 300 mg on day 1. The primary outcome was stroke (ischemic or hemorrhagic) during 90 days of follow-up in an intention-to-treat analysis. Treatment differences were assessed with the use of a Cox proportional-hazards model, with study center as a random effect. Results Stroke occurred in 8.2% of patients in the clopidogrel-aspirin group, as compared with 11.7% of those in the aspirin group (hazard ratio, 0.68; 95% confidence interval, 0.57 to 0.81; P<0.001). Moderate or severe hemorrhage occurred in seven patients (0.3%) in the clopidogrel-aspirin group and in eight (0.3%) in the aspirin group (P=0.73); the rate of hemorrhagic stroke was 0.3% in each group. Conclusions Among patients with TIA or minor stroke who can be treated within 24 hours after the onset of symptoms, the combination of clopidogrel and aspirin is superior to aspirin alone for reducing the risk of stroke in the first 90 days and does not increase the risk of hemorrhage. (Funded by the Ministry of Science and Technology of the People's Republic of China; CHANCE ClinicalTrials.gov number, NCT00979589 .).

Concepts: Blood, Stroke, Transient ischemic attack, People's Republic of China, Subarachnoid hemorrhage, Aspirin, Randomness, People's Republic

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The mortality after aneurysmal subarachnoid hemorrhage (SAH) is 50%, and most survivors suffer severe functional and cognitive deficits. Half of SAH patients deteriorate 5 to 14 days after the initial bleeding, so-called delayed cerebral ischemia (DCI). Although often attributed to vasospasms, DCI may develop in the absence of angiographic vasospasms, and therapeutic reversal of angiographic vasospasms fails to improve patient outcome. The etiology of chronic neurodegenerative changes after SAH remains poorly understood. Brain oxygenation depends on both cerebral blood flow (CBF) and its microscopic distribution, the so-called capillary transit time heterogeneity (CTH). In theory, increased CTH can therefore lead to tissue hypoxia in the absence of severe CBF reductions, whereas reductions in CBF, paradoxically, improve brain oxygenation if CTH is critically elevated. We review potential sources of elevated CTH after SAH. Pericyte constrictions in relation to the initial ischemic episode and subsequent oxidative stress, nitric oxide depletion during the pericapillary clearance of oxyhemoglobin, vasogenic edema, leukocytosis, and astrocytic endfeet swelling are identified as potential sources of elevated CTH, and hence of metabolic derangement, after SAH. Irreversible changes in capillary morphology and function are predicted to contribute to long-term relative tissue hypoxia, inflammation, and neurodegeneration. We discuss diagnostic and therapeutic implications of these predictions.Journal of Cerebral Blood Flow & Metabolism advance online publication, 25 September 2013; doi:10.1038/jcbfm.2013.173.

Concepts: Blood, Blood vessel, Stroke, Traumatic brain injury, Ischemia, Reperfusion injury, Subarachnoid hemorrhage, Hypoxia

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Aneurysmal subarachnoid hemorrhage (SAH) carries high early patient mortality. More women than men suffer from SAH and the average age of female SAH survivors is greater than that of male survivors; however, the overall mortality and neurological outcomes are not better in males despite their younger age. This pattern suggests the possibility of gender differences in the severity of initial impact and/or in subsequent pathophysiology. We explored gender differences in survival and pathophysiology following subarachnoid hemorrhage induced in age-matched male and female rats by endovascular puncture. Intracranial pressure (ICP), cerebral blood flow (CBF), blood pressure (BP) and cerebral perfusion pressure (CPP) were recorded at and after induction of SAH. Animals were sacrificed 3 hours after lesion and studied for subarachnoid hematoma size, vascular pathology (collagen and endothelium immunostaining), inflammation (platelet and neutrophil immunostaining), and cell death (TUNEL assay). In a second cohort, 24-hour survival was determined. Subarachnoid hematoma, post-hemorrhage ICP peak, BP elevation, reduction in CPP, intraluminal platelet aggregation and neutrophil accumulation, loss of vascular collagen, and neuronal and non-neuronal cell death were greater in male than in female rats. Hematoma size did not correlate with the number of apoptotic cells, platelet aggregates or neutrophil. The ICP peak correlated with hematoma size and with number of apoptotic cells but not with platelet aggregates and neutrophil number. This suggests that the intensity of ICP rise at SAH influences the severity of apoptosis but not of inflammation. Mortality was markedly greater in males than females. Our data demonstrate that in rats gender influences the initial impact of SAH causing greater bleed and early injury in males as compared to females.

Concepts: Male, Blood, Female, Traumatic brain injury, Intracranial pressure, Gender, Sex, Subarachnoid hemorrhage

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To determine the nationwide incidence of subarachnoid hemorrhage (SAH) and report nationwide changes in smoking rates between 1998 and 2012 in Finland.

Concepts: Subarachnoid hemorrhage, Nationwide Building Society, Building society, Cheshire Building Society, Nationwide

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BACKGROUND:Hospital mortality has decreased over time for critically ill patients with various forms of brain injury. We hypothesized that the proportion of patients who progress to neurologic death may have also decreased. METHODS:We performed a prospective cohort study involving consecutive adult patients with traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage or anoxic brain injury admitted to regional intensive care units in southern Alberta over a 10.5-year period. We used multivariable logistic regression to adjust for patient age and score on the Glasgow Coma Scale at admission, and to assess whether the proportion of patients who progress to neurologic death has changed over time. RESULTS:WeThe cohort consisted of 2788 patients. The proportion of patients who progressed to neurologic death was 8.1% at the start of the study period, and the adjusted odds of progressing to neurologic death decreased over the study period (odds ratio [OR] per yr 0.92, 95% confidence interval [CI] 0.87-0.98, p = 0.006). This change was most pronounced among patients with traumatic brain injury (OR per yr 0.87, 95% CI 0.78-0.96, p = 0.005); there was no change among patients with anoxic injury (OR per yr 0.96, 95% CI 0.85-1.09, p = 0.6). A review of the medical records suggests that missed cases of neurologic death were rare (≤ 0.5% of deaths). INTERPRETATION:The proportion of patients with brain injury who progress to neurologic death has decreased over time, especially among those with head trauma. This finding may reflect positive developments in the prevention and care of brain injury. However, organ donation after neurologic death represents the major source of organs for transplantation. Thus, these findings may help explain the relatively stagnant rates of deceased organ donation in some regions of Canada, which in turn has important implications for the care of patients with end-stage organ failure.

Concepts: Epidemiology, Death, Stroke, Traumatic brain injury, Intensive care medicine, Subarachnoid hemorrhage, Glasgow Coma Scale, Coma

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Background-Large-scale prospective epidemiological data testing the association between physical activity (PA) and cerebrovascular diseases (CVDs) are scarce, particularly in Europe. The objective was to assess the risk of CVD according to PA levels in adults. METHODS: We included a total of 13 576 men and 19 416 women aged 29 to 69 years and participating in the European Prospective Investigation into Cancer and Nutrition cohort in Spain, recruited between 1992 and 1996 and followed-up until 2006 to ascertain incident CVD events. The validated European Prospective Investigation into Cancer and Nutrition PA questionnaire was used to assess metabolic equivalent × hours per week dedicated to different types of PA. Hazard ratios of CVD by PA levels were estimated using multivariate Cox regression. Extensive baseline data collected on diet, lifestyle habits, medical history, and anthropometry were available to adjust for. RESULTS: A total of 210 transient ischemic attacks and 442 stroke cases (80% ischemic, 10% hemorrhagic, 7% subarachnoid hemorrhage, and 3% mixed or unspecified) were registered after 12.3 years of mean follow-up. Recreational activity was inversely associated with risk of CVD in women but not in men. Women walking for ≥3.5 hours per week were at lower risk of stroke than those who did not engage in regular walking. No significant associations were found for other leisure time activities or vigorous PA with CVD in either sex. CONCLUSIONS: Recreational PA of moderate intensity was inversely associated with stroke incidence in women, whereas PA showed no effect on CVD risk in men. Increasing time dedicated to activities such as walking would be expected to help to reduce the stroke burden in women.

Concepts: Epidemiology, Nutrition, Obesity, Stroke, Subarachnoid hemorrhage, Cardiovascular system, Cerebral hemorrhage, Leisure

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Rates of acute intracerebral hemorrhage (ICH) increase in winter months but the magnitude of risk is unknown. We aimed to quantify the association of ambient temperature with the risk of ICH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT2) participants on an hourly timescale.

Concepts: Blood, Stroke, Bleeding, The Association, Subarachnoid hemorrhage, Cerebral hemorrhage, Winter, Coagulopathy

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Nicardipine and labetalol are two commonly used antihypertensives for treating elevated blood pressures in the setting of intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). There are no studies comparing these two agents as continuous infusions.

Concepts: Blood, Hypertension, Stroke, Blood pressure, Artery, Subarachnoid hemorrhage, Cerebral hemorrhage, Orthostatic hypotension

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Cerebral vasospasm (CV) and the resulting delayed cerebral ischemia (DCI) significantly contribute to poor outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Free hemoglobin (Hb) within the subarachnoid space has been implicated in the pathogenesis of CV. Haptoglobin (Hp) binds free pro-oxidant Hb, thereby modulating its harmful effects. Humans can be of three Hp phenotypes: Hp1-1, Hp2-1, or Hp2-2. In several disease states, the Hp2-2 protein has been associated with reduced ability to protect against toxic free Hb. We hypothesized that individuals with the Hp2-2 phenotype would have more CV, DCI, mortality, and worse functional outcomes after aSAH. In a sample of 74 aSAH patients, Hp2-2 phenotype was significantly associated with increased focal moderate (P = 0.014) and severe (P = 0.008) CV and more global CV (P = 0.014) after controlling for covariates. Strong trends toward increased mortality (P = 0.079) and worse functional outcomes were seen for the Hp2-2 patients with modified Rankin scale at 6 wk (P = 0.076) and at 1 y (P = 0.051) and with Glasgow Outcome Scale Extended at discharge (P = 0.091) and at 1 y (P = 0.055). In conclusion, Hp2-2 phenotype is an independent risk factor for the development of both focal and global CV and also predicts poor functional outcomes and mortality after aSAH. Hp phenotyping may serve as a clinically useful tool in the critical care management of aSAH patients by allowing for early prediction of those patients who require increased vigilance due to their inherent genetic risk for the development of CV and resulting DCI and poor outcomes.

Concepts: Gene, Modified Rankin Scale, Phenotype, Subarachnoid hemorrhage, Cerebrospinal fluid, Wilhelm Johannsen, Vasospasm, Subarachnoid space