Comparison of biothesiometry and neuro-urophysiological investigations for the clinical evaluation of patients with erectile dysfunction

In the literature the determination of the vibration sensitivity threshold of the penile glans by means of biothesiometry has been introduced as a cost-effective office test for the evaluation of penile neuropathy in impotent men. At our facility we have gained extensive experience with neuro-urophysiological tests for the evaluation of penile innervation. These neuro-urophysiological tests have the disadvantage of complexity, invasiveness and time consumption. In our study both methods were compared in 31 impotent patients. The results showed that penile glans biothesiometry yields consistent results when measurements are repeated during 1 session. However, no relationship was found between the outcome of penile glans biothesiometry and neuro-urophysiological tests of the dorsal penile nerve, which is probably due to the fact that vibration is not an adequate stimulus to the skin of the penile glans that contains free nerve endings (that is pain receptors) only, and hardly any vibration receptors. We conclude that biothesiometric investigation of penile glans innervation is unsuited for the evaluation of penile innervation and cannot replace neuro-urophysiological tests.