Cerebral responses evoked by stimulation of vesico-urethral junction in man: methodological evaluation of monopolar...

Cerebral responses after bipolar stimulation (BpS) and monopolar stimulation (MpS) of the vesico-urethral junction (VUJ), as well as skin surface stimulation of various hip and pelvic structures, were recorded in 13 normal control subjects. BpS of VUJ produced cerebral evoked potentials (CEPs) with a negative peak (mean latency 88.69 +/- 13.73 msec) following a smaller positive deflection, while MpS of the same sites with indifferent electrodes placed on various pelvic or hip structures resulted in different response latencies that were all significantly shorter than those of BpS. Shape and latency of responses after MpS of VUJ were similar to those elicited by skin surface stimulation of the abdominal wall and the iliac crest; those elicited by pudendal nerve stimulation at the glans were also similar in shape but significantly greater in latency. Results strongly indicate that during MpS of VUJ the somatic or muscle afferents located in the hip and pelvic region are stimulated; consequently, BpS technique should be considered the preferred technique for investigating the physiological condition of visceral afferents arising from VUJ.