Abstract:
Electrodiagnostic tests measuring the activities of cavernous smooth muscle and sudomotor
structures of penile skin are used in order to evaluate autonomic innervation of the penis. Owing to
closeness of these tissues, the interference of sympathetic activity during recording is a possibility.
In this study, we investigated this possibility in 10 patients whose cavernosal tissues were destroyed
during penile prosthesis implantation by comparing the pre- and postoperative penile skin
electrodermal activities. Penile electrodermal activities were recorded with surface electrodes
before and after the operation. All of the patients had spontaneous and evoked penile electrodermal
activity (EDA). The mean amplitude of evoked EDA decreased from 21597700 to 14137515 lV
following penile prosthesis surgery (P ¼ 0.017). The decrease in the amplitude of penile-evoked EDA
following penile prosthesis implantation suggests the contribution of cavernous smooth muscle
activity to the sudomotor responses prior to operation. Although corpus cavernosum sympathetic
activity contributes to the penile skin recordings, these recordings are mostly the result of penile
skin sudomotor sympathetic activity. Therefore, surface potentials recorded from penile skin
should not be used for the evaluation of autonomic innervation of corpus cavernosum.
