Urethral hypotonicity after suprasacral spinal cord injury.

Established suprasacral spinal cord injuries usually are associated with detrusor hyperreflexia and varying degrees of detrusor-sphincter dyssynergia. Occasionally, such injuries result in detrusor areflexia or urethral hypotonicity or both. The results of the urodynamic evaluation of 4 patients with suprasacral spinal cord injuries are described. Detrusor areflexia and urethral hypotonicity were demonstrated in 3 cases and urethral smooth muscular hypotonia but preserved reflex detrusor function in 1. It is shown that destruction of the thoracolumbar sympathetic outflow can cause the complete loss of urethral smooth muscular closing function and that resting urethral closure is totally independent of preganglionic cholinergic influences.