ABSTRACT SUMMARY Kilohertz sacral root block for bladder emptying after spinal cord injury Neurogenic bladder and bowel post-SCI hugely impact quality of life and remains important unmet challenges. Neurogenic bladder and bowel are the result of impaired control/coordination between the bladder and urethral sphincter. In particular, detrusor-sphincter dyssynergia (DSD) results in urethral sphincter activity that obstructs the bladder outlet during bladder emptying. Current treatment approaches, which include such things as timed voiding strategies, catheters, pharmaceuticals, and surgical interventions, do not sufficiently address the problem. Sacral anterior root stimulation (SARS) has been used to provide clinically effective bladd er emptying for individuals with SCI. SARS activates the motor nerves of the bladder to evoke bladder contractions for emptying. For individuals with DSD, reflex urethral sphincter activity can still impede bladder emptying. Therefore, these reflex urethral contractions must be eliminated. Posterior rhizotomy, which is cutting the spinal nerves that carry sensory signals, has been combined with SARS to abolish reflex contractions of the sphincter and facilitate emptying. However, many individuals choose not to undergo the combination of SARS with rhizotomy because the rhizotomy abolishes any remaining pelvic sensation and desirable reflexes, including reflex sexual functions such as penile erection. One promising approach uses high frequency stimulation to b lock the motor efferent neurons that drive urethral sphincter contractions. This technique has been tested via pudendal nerve stimulation to reduce urethral sphincter pressures and promote bladder emptying. The goal of this project is to determine the effect of sacral root stimulation frequency on contractile function of lower urinary tract and bowel organs in order to evaluate the potential for SARS to improve bladder and bowel emptying efficiency for individuals with spinal cord injury. In acute terminal pig experiments, we will measure continuous bladder, urethral sphincter, rectal, and anal sphincter pressures in response to SARS at varying frequencies from 20-10,000 Hz. We will also measure bladder emptying volumes and rates.