The Ferrier lecture, 1986. The actions of parasympathetic and sympathetic nerves in human micturition, erection and seminal emission, and their restoration in paraplegic patients by implanted electrical stimulators.

Implants that stimulate the S2, S3 and S4 anterior roots improve micturition, defaecation and penile erection in many patients with spinal-cord injuries. The posterior rhizotomy that is commonly done at the same time usually cures their urinary incontinence, and may greatly improve bladder compliance. Implants that stimulate the hypogastric plexus allow semen to be obtained easily from some men with spinal injuries who cannot ejaculate, and may allow an implant-driven erection. A little new knowledge about the neurophysiology of the pelvic organs has come from studying the performance of these implants.