Experience with electromyography of the external urethral sphincter in spinal cord injury patients.

Simultaneous recordings of electromyography of the external urethral sphincter and bladder pressure during voiding were done for 71 male patients with spinal cord injury. Discordant activities between the anal and the external urethral sphincters were noted in 39 per cent of the patients. The degree of bladder dysfunction was related more to the degree of dyssynergia of the urethral than the anal sphincter. This detrusor-sphincter dyssynergia was found in 67 per cent of our patients regardless of the differences in cystometric patterns and the level of spinal injury. The importance of electromyography of the external urethral sphincter in the diagnosis of neurogenic bladder dysfunction was stressed. The management of detrusor-sphincter dyssynergia is discussed briefly.