This is a request for funding of a feasibility study for head injury, to provide for programmatic development leading to the creation of a head injury clinical research center. Four research projects and a core facility are proposed. Project 1: Will establish and develop animal models of traumatic brain injury. The aim is to utilize these models to study the role of ion dynamics, particularly their role in secondary injury. The relevance of ionic shifts to the development of management strategies will be emphasized. These studies will fill a major gap in this field and the characterization of the models developed serve as a basis for the development of new and hopefully clinically relevant therapeutic interventions. Project 2: Will develop methods and measures of cognitive and behavioral interventions. The long term goal will be to establish a program of neurobehavioral interventions leading to improvement in the major causes of long term disability in the head injured population. Project 3: Will assess the role of early administration of high dose methylprednisolone on the outcome of patients with moderate and severe traumatic brain injury. Outcome will be assessed by quantitative measures of cognitive and behavioral function developed by investigators in the Core Facility of this program. Project 4: Will test the feasibility of electrical stimulation of deep brain structures to modify the neurobehavioral status of patients with post-traumatic coma - persistent vegetative state. Electrophysiologic, behavioral and cognitive methods will be developed and tested as measures of outcome in this project. The Core Facility will support all projects in this proposal. This facility will be responsible for the establishment of methods of tracking patients admitted to the Institution with traumatic brain injury. The long term goals are to characterize the patient population served by the institution; to define the neurologic, cognitive and behavioral outcome of this population; and to develop biostatistical methods to address the effects of acute, subacute and chronic interventions on the long term functional status of the traumatic brain injured patient population.