Stroke; a journal of cerebral circulation
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Xenon provides short-term neuroprotection in neonatal rats when administered after hypoxia-ischemia.
Brain injury after hypoxic-ischemic insults evolves via an apoptotic/necrotic cascade. Glutamate over release and N-methyl-d-aspartate (NMDA) receptor over activation (excitotoxicity) are believed to trigger this process. Xenon is a nontoxic anesthetic gas that reduces neurotransmitter release and functionally antagonizes NMDA receptors. Administering xenon to hypoxic-ischemic newborns might be clinically effective if the neurotoxic processes continue evolving after delivery. We sought to determine whether xenon administration after the initial hypoxic-ischemic insult was neuroprotective. ⋯ Three hours of xenon administration commenced after hypoxia-ischemia in neonatal rats provides short-term neuroprotection. This finding suggests that treatment with xenon after perinatal asphyxia would also be neuroprotective. Because xenon does not cause other neurotoxic effects and has demonstrated minimal side effects in extensive anesthesia studies, it would make an ideal candidate for the treatment after human perinatal hypoxia-ischemia.
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It is still unclear that impaired cerebrovascular reactivity (CVR) to acetazolamide is comparable to elevated oxygen extraction fraction (OEF) on positron emission tomography (PET) in patients with occlusive carotid diseases. Therefore, in this study, the authors aimed to clarify whether OEF is elevated in all patients with reduced cerebral blood flow (CBF) and CVR (type 3) on single photon emission computed tomography (SPECT), and, if not, to specify the underlying pathophysiology of type 3 but normal OEF. ⋯ The results strongly suggest that type 3 patients with reduced CBF and CVR may be divided into 2 pathophysiologically different subgroups: misery perfusion attributable to hemodynamic compromise and matched hypometabolism attributable to incomplete infarction. Type 3 but normal OEF may represent a transition stage from misery perfusion to matched hypometabolism.
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Anticoagulation-related intracerebral hemorrhage (ICH) is often fatal, and rapid reversal of anticoagulation is the most appealing strategy currently available for treatment. We sought to determine whether particular emergency department (ED) interventions are effective in reversing coagulopathy and improving outcome. ⋯ Time to treatment is the most important determinant of 24-hour anticoagulation reversal. Although additional study is required to determine the clinical benefit of rapid reversal of anticoagulation, minimizing delays in FFP administration is a prudent first step in emergency management of warfarin-related ICH.
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Recruitment rate is a major determinant of the duration, cost, and feasibility of acute stroke trials. ⋯ Recruitment rates for acute stroke trials are influenced by organizational structure and study entry criteria. Characterizing predictors of recruitment may help optimize future trial design.