Mictunrition and the sacral reflex arc: lessons from electrophysiological techniques

Electrophysiological techniques applied either for diagnostic or therapeutic reasons have contributed to elucidation of the neurocontrol of micturition. But the ability of electrophysiological diagnostic tests to reveal neurogenic involvement in patients suffering from lower urinary tract dysfunction is limited, and has been overestimated. Furthermore, the correlation between a proven neurogenic deficit and the consecutive dysfunction is complex. The electrophysiological tests, however, may also be applied for testing the central nervous system integrative function, such as in testing reflex thresholds, excitability levels of motor nuclei, etc. The use of electrical stimulation for therapeutic purposes has instigated much physiological research. Insights related to micturition neurocontrol, as for instance that afferent inputs from lumbosacral and vesical sensory fibres modulate the micturition threshold, are being therapeutically exploited. It is expected that further use of electrophysiological techniques, being complementary to functional neuroimaging, will clarify particularly the temporal aspects of neurocontrol mechanisms involved in micturition.