Cerebral responses evoked by stimulation of the vesico-urethral junction in normal subjects.

Following bipolar stimulation of the vesico-urethral junction (VUJ), evoked potentials (EPs) with a late and prominent negativity (mean latency 91.4 +/- 11.0 msec) were recorded from scalp in 22 male subjects. Although remarkable intersubject variations occurred, no peak variation could be seen in any given subject. Maximum amplitude of the EPs was recorded from Cz and CzP points. Stimuli with various frequencies did not lead to any differences in shape and latency of EPs. The differences between the EPs by bipolar stimulation of the VUJ and the responses elicited by distal urethral and pudendal nerve stimulation suggest that, during bipolar stimulation of VUJ, the somatic afferents were not excited. Therefore, these responses were most likely due to the excitement of the visceral afferents arising from the VUJ separately. This method may be a useful technique for evaluating the physiological condition of the afferent nerves arising from VUJ.