Low sodium levels (hyponatremia) are a frequent occurrence in medically ill patients, and in particular those with neurological injury. Hyponatremia has been associated with worse outcome, problems with memory and concentration and impaired balance. Standard treatment for low sodium (salt) levels is to give the patient a salt containing solution thru a catheter (small flexible tube) in a vein in the arm or leg. One of the major complications of this treatment is excess body fluid which may cause heart problems or accumulation of fluid in the lungs and may require additional medications to remove extra water from the body.