Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Nov 2014
ReviewDeath and consciousness--an overview of the mental and cognitive experience of death.
Advances in resuscitation science have indicated that, contrary to perception, death by cardiorespiratory criteria can no longer be considered a specific moment but rather a potentially reversible process that occurs after any severe illness or accident causes the heart, lungs, and brain to stop functioning. The resultant loss of vital signs of life (and life processes) is used to declare a specific time of death by physicians globally. When medical attempts are made to reverse this process, it is commonly referred to as cardiac arrest; however, when these attempts do not succeed or when attempts are not made, it is called death by cardiorespiratory criteria. ⋯ Recollections reported by millions of people in relation to death, so-called out-of-body experiences (OBEs) or near-death experiences (NDEs), are often-discussed phenomena that are frequently considered hallucinatory or illusory in nature; however, objective studies on these experiences are limited. To date, many consistent themes corresponding to the likely experience of death have emerged, and studies have indicated that the scientifically imprecise terms of NDE and OBE may not be sufficient to describe the actual experience of death. While much remains to be discovered, the recalled experience surrounding death merits a genuine scientific investigation without prejudice.
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Ann. N. Y. Acad. Sci. · Sep 2012
ReviewHow baseline severity affects efficacy and safety outcomes in acute ischemic stroke intervention trials.
Baseline severity of stroke may be an important predictor of efficacy and safety outcomes in acute stroke intervention trials. This summary explores definitions of baseline variables and outcomes used to measure stroke severity, efficacy, and safety. In addition, the discussion here reviews select acute ischemic stroke intravenous thrombolytic studies, such as the National Institute of Neurological Disorders and Stroke rt-PA Stroke Study and European Cooperative Acute Stroke Studies, select neuroprotectant and endovascular clot retrieval device studies, and large cooperative databases, such as the Virtual International Stroke Trials Archive and Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry, to explore relationships between baseline stroke severity and other possible factors associated with efficacy and safety outcomes. The NIH Stroke Scale and modified Rankin scale will be featured as major stroke outcome measures, based on frequency of use and reliability, familiarity, adaptability, and comparability.
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Although the precise mechanisms for control of consciousness are not fully understood, emerging data show that conscious information processing depends on the activation of certain networks in the brain and that the impairment of consciousness is related to abnormal activity in these systems. Epilepsy can lead to transient impairment of consciousness, providing a window into the mechanisms necessary for normal consciousness. ⋯ We discuss a "network inhibition hypothesis" in which focal temporal lobe seizure activity disrupts normal cortical-subcortical interactions, leading to depressed neocortical function and impaired consciousness. This review of the major prior theories of impaired consciousness in epilepsy allows us to put more recent data into context and to reach a better understanding of the mechanisms important for normal consciousness.
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Ann. N. Y. Acad. Sci. · Nov 2014
ReviewDevelopment of the Trevo ProVue Retriever for intracranial clot removal in acute ischemic stroke.
It is estimated that 15 million people worldwide have a stroke each year. Of the estimated 795,000 strokes that occur in the United States annually, the majority are ischemic strokes resulting from an obstruction within a vessel supplying blood to the brain. The treatment goal for these patients is to restore blood flow as quickly as possible. ⋯ Food and Drug Administration clearance in 2012, the Trevo® Retriever is a stent-like structure to be deployed at the site of an occlusion to allow the occluding thrombus to integrate into the device for subsequent removal and restoration of blood flow. The subsequent generation of the device, the ProVue Retriever, is fully radiopaque and designed to provide physicians with maximal information about the interaction of the device with the clot, providing enhanced feedback during the procedure. In this brief historical review, the development pathway, clinical experience, and future directions of the Trevo devices are summarized.
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Hemorrhagic transformation (HT) associated with recombinant tissue plasminogen activator (rt-PA) complicates and limits its use in stroke. Here, we provide a focused review on the involvement of matrix metalloproteinase 9 (MMP-9) in rt-PA-associated HT in cerebral ischemia, and we review emerging evidence that the selective inhibitor of the sulfonylurea receptor 1 (Sur1), glibenclamide (U. ⋯ A retrospective clinical study comparing outcomes in diabetic patients with stroke treated with rt-PA showed that those who were previously on and were maintained on a sulfonylurea fared significantly better than those whose diabetes was managed without sulfonylureas. Inhibition of Sur1 with injectable glyburide holds promise for ameliorating rt-PA-associated HT in stroke.