Interventional neurophysiology of the sacral nervous system

Clinical neurophysiological tests have been introduced for the sacral neuro muscular system to aid with diagnosis of neurogenic conditions involving th e lower urinary tract, anorectal and sexual dysfunction. The tests have, ho wever, the potential to be of value In different interventions outside of t he neuro physiological laboratory. EMG monitoring can be used for exact app lication of botulinum toxin by the relatively non-invasive transcutaneous a pproach in treatment of male detrusor sphincter dyssynergia. Checking for c ompound muscle action potentials of the external anal sphincter is proposed as the best method for exact placement of wire electrodes close to the 3rd sacral roots in treating lower urinary tract dysfunction by 'neuromodulati on'. Presently the most established use of clinical neurophysiological tech niques - outside the laboratory - as related to the sacral neuromuscular sy stem Is in the operating theatre. These tests have been introduced to ident ify relevant structures, for instance pudendal afferents within dorsal sacr al roots, which should be spared during rhizotomy procedures for treatment of spasticity. Modified techniques are used intraoperatively to monitor the integrity of the lower sacral reflex arc (the bulbocavernosus reflex) or t he lower sacral afferents throughout the spinal cord (pudendal SEP). Clinic al neurophysiological tests are expected to become established in several I nterventions involving the sacral neuromuscular system. (C) 2001 Editions s cientifiques et medicales Elsevier SAS.