Electromyelography, a useful test for evaluation of the sacral spinal cord

Bradley was the first to describe an accurate and objective test for the evaluation of the integrity of the sacral spinal cord involved with micturition. Measurements of the latency time from an electrical stimulation of the proximal urethra and its response, the contraction of the anal sphincter, was found to be approximately 70 msec. The neural pathways involved with this reflex include the afferent pelvic nerves and the efferent pudendal nerves. Prolonged latency times signify damage to this sacral arc. This testing, which Bradley termed electromyelography, can help to diagnose, in a more definitive fashion, some abnormalities of micturition. We report on 3 patients with varied lesions of the sacral neural pathways and their urodynamic evaluation, including cystometry, sphincter electromyography and measurements of latency times of evoked responses of the anal sphincter. All 3 cases showed prolonged latency times with 1 reverting to normal after improvement of the underlying disorder. The usefulness of electromyelography and its ease of implementation are stressed. Measurements of evoked response may be an important addiction in the evaluation of complicated neurourological problems.