Handbook of clinical neurology
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Traumatic brain injury, a leading cause of mortality and morbidity, is divided into three grades of severity: mild, moderate, and severe, based on the Glasgow Coma Scale, the loss of consciousness, and the development of post-traumatic amnesia. Although mild traumatic brain injury, including concussion and subconcussion, is by far the most common, it is also the most difficult to diagnose and the least well understood. Proper recognition, management, and treatment of acute concussion and mild traumatic brain injury are the fundamentals of an emerging clinical discipline. ⋯ The incidence and prevalence of chronic traumatic encephalopathy and the genetic risk factors critical to its development are currently unknown. Chronic traumatic encephalopathy frequently occurs as a sole diagnosis, but may be associated with other neurodegenerative disorders, including Alzheimer's disease, Lewy body disease, and motor neuron disease. Currently, chronic traumatic encephalopathy can be diagnosed only at autopsy; however, promising efforts to develop imaging, spinal fluid, and peripheral blood biomarkers are underway to diagnose and monitor the course of disease in living subjects.
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Mild traumatic brain injury (TBI) is common but accurate diagnosis and defining criteria for mild TBI and its clinical consequences have been problematic. Mild TBI causes transient neurophysiologic brain dysfunction, sometimes with structural axonal and neuronal damage. Biomarkers, such as newer imaging technologies and protein markers, are promising indicators of brain injury but are not ready for clinical use. ⋯ Effective early phase management may prevent or limit the later phase disorder and should include education about symptoms and expectations for recovery, as well as recommendations for activity modifications. Later phase treatment should be informed by thoughtful differential diagnosis and the multiplicity of premorbid and comorbid conditions that may influence symptoms. Treatment should incorporate a hierarchical, sequential approach to symptom management, prioritizing problems with significant functional impact and effective, available interventions (e.g., headache, depression, anxiety, insomnia, vertigo).
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Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Despite extensive preclinical research supporting the effectiveness of neuroprotective therapies for brain trauma, there have been no successful randomized controlled clinical trials to date. TBI results in delayed secondary tissue injury due to neurochemical, metabolic and cellular changes; modulating such effects has provided the basis for neuroprotective interventions. ⋯ We discuss the concept of utilizing multipotential drugs that target multiple secondary injury pathways, rather than more specific "laser"-targeted strategies that have uniformly failed in clinical trials. Moreover, we assess data supporting use of neuroprotective drugs that are currently being evaluated in human clinical trials for TBI, as well as promising emerging experimental multipotential drug treatment strategies. Finally, we describe key challenges and provide suggestions to improve the likelihood of successful clinical translation.
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Traumatic brain injury (TBI) is an important cause of death and disability, particularly in younger populations. The prehospital evaluation and management of TBI is a vital link between insult and definitive care and can have dramatic implications for subsequent morbidity. Following a TBI the brain is at high risk for further ischemic injury, with prehospital interventions targeted at reducing this secondary injury while optimizing cerebral physiology. ⋯ We evaluate patient management strategies including indications for advanced airway management, oxygenation, ventilation, and fluid resuscitation, as well as prehospital strategies for the management of suspected or impending cerebral herniation including hyperventilation and brain-directed hyperosmolar therapy. Transport decisions including the role of triage models and trauma centers are discussed. Finally, future directions in the prehospital management of traumatic brain injury are explored.
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Over the past 20 years or so, functional magnetic resonance imaging (fMRI) has proven to be an influential tool for measuring perceptual and cognitive processing non-invasively in the human brain. This article provides a brief yet comprehensive overview of this dominant method for human auditory neuroscience, providing the reader with knowledge about the practicalities of using this technique to assess central auditory coding. ⋯ The future utility of fMRI and anticipated technical developments is also briefly evaluated. Throughout the review, key concepts are illustrated using specific author examples, with particular emphasis on fMRI findings that address questions pertaining to basic sound coding (such as frequency and pitch).