Spinal cord injury causes many bladder complications for life, such as impaired bladder emptying, recurrent urinary tract infection and stones, kidney damage, and incontinence, which impair health and quality of life and result in considerable cost to health care systems, in spite of state of the art management using medications, appliances and surgery. These complications are often due to unco-ordinated and unwanted contractions of the bladder and the external urethral sphincter, the muscle that restricts the flow of urine out of the bladder through the urethra. Contraction of the sphincter has been managed by cutting the sphincter or the nerves to the sphincter, inserting cylindrical metal mesh "stents" to keep it open, and injection of muscle toxins into the sphincter, but none of these is ideal and some have significant complications, and many patients require intermittent or indwelling catheters to remove urine from the bladder, and these too have their complications. Recently a technique has been developed and refined to block conduction in nerves rapidly and reversibly using electrical stimulation, and this has been used in animals with chronic spinal cord injury to prevent contraction in the pudendal nerves to the sphincter and to allow reliable emptying of the bladder. This project proposes to test this technique for the first time in human subjects with chronic spinal cord injury, using electrodes that can be inserted through a needle and left in place for several days and used to apply electrical stimulation while measuring the ability of human subjects to empty the bladder in the laboratory. After making these measurements the electrodes will be removed by pulling gently on them. If this project is successful it will justify the development and testing of a stimulation system that can be fully implanted by surgery to provide long term management of this problem.
This project is directly relevant to the health care needs of veterans with spinal cord injury. Complications of the neurogenic bladder and bowel are common and costly and greatly impair the quality of life of Veterans. Current management using medications, appliances and surgery does not prevent these complications adequately. The VA has invested in previous research into electrical stimulation with some success, although previous attempts to control the bladder electrically often required cutting of nerves. New discoveries based on animal research in the VA Functional Electrical Stimulation Center that promise to make such cutting of nerves unnecessary are now poised to be translated into human application and have the potential not only to improve health and quality of life but also to reduce costs of care to the Department of Veterans Affairs.