Seminars in neurology
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Seminars in neurology · Sep 2006
ReviewEthical issues in critical care and cardiac arrest: clinical research, brain death, and organ donation.
Cardiac arrest results in global hypoxic-ischemic brain injury from which there is a range of possible neurological outcomes. In most cases, patients may require a surrogate to make decisions regarding end-of-life care, including the withdrawal of life-sustaining therapies. This article reviews ethical considerations that arise in the clinical care of patients following cardiac arrest, including decisions to continue or withdraw life-sustaining therapies; brain death determination; and organ donation in the context of brain death and cardiac death (so-called non-heart-beating donation). This article also discusses ethical concerns pertaining to the design and conduct of resuscitation research that is necessary for the development of effective therapies to prevent anoxic brain injury or promote neurological recovery.
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Beyond the cerebral impact of cardiac arrest, recent research indicates a high prevalence of neurological disturbances such as delirium and coma among patients admitted to the intensive care unit (ICU). These disturbances, grouped here under the term "encephalopathy," may be overlooked while attention is devoted to reversing life-threatening imbalances in cardiac and pulmonary function. Nevertheless, there is ample evidence that encephalopathy is an independent predictor of mortality. ⋯ Although encephalopathy may resolve with treatment of the underlying disorder, there is mounting evidence that cerebral dysfunction persists beyond the acute phase of critical illness. ICU survivors often suffer chronic impairments in cognitive ability, suggesting occult brain injury. The pathogenesis and natural history of encephalopathy, still poorly understood, need further clarification to spur the development of effective preventive and therapeutic interventions.
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Seminars in neurology · Sep 2006
ReviewMechanisms of injury in hypoxic-ischemic encephalopathy: implications to therapy.
Cardiac arrest survivors commonly suffer ischemic brain injury, and understanding the mechanisms of injury is essential to providing insight for effective therapies for brain protection. Injury can occur at the time of the cardiac arrest and is dependent not only on the duration but also the degree of impaired circulation. ⋯ This section will review the molecular basis of injury with cardiac arrest and will elucidate the different mechanisms of injury between cardiac arrest, pure respiratory arrest, and arrest secondary to toxins (e.g., carbon monoxide). The rationale for multiple postarrest therapies, such as hypothermia and induced hypertension, will also be reviewed.
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Seminars in neurology · Apr 2006
Review Historical ArticleParoxysmal hemicrania, SUNCT, and hemicrania continua.
The trigeminal autonomic cephalalgias (TACs) are a group of primary headache disorders characterized by unilateral pain in the somatic distribution of the trigeminal nerve and ipsilateral autonomic signs, which reflect activation of the cranial parasympathetic pathway. The group includes cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing. Hemicrania continua was previously classified as one of the TACs. Despite their common elements, individually these headaches differ with respect to attack duration, frequency, and response to indomethacin.