The nature of spontaneous cavernosal activity.

Objective: To determine the characteristics of spontaneous cavernosal activity (SCA) and to relate this to previous descriptions of spontaneous potentials from the cavernosum (single potential analysis of cavernosal activity, SPACE).

Subjects And Methods: The SCA was recorded in 31 normal men with no sexual problems; various manipulations were applied using concentric-needle (CN), bipolar needle (BN) and surface electrodes. The electrical activity was compared with the observed slow retractile movements of the flaccid penis and with other assessments of electrical activity from skin.

Results: SCA appeared synchronously from both sides of the cavernosal bodies in all normal subjects when detected by CN electrodes. The synchronous recordings both by CN and BN electrodes, or both by CN and surface electrodes registered similar oscillatory potentials. Slow retractile movements of the penis occurred synchronously with these potentials in all subjects and both were absent during erection.

Conclusion: SCA is apparently related to biomechanical slow movement artefacts of the flaccid penis: it may be a consequence of the summed contractions of smooth muscle groups in the cavernosum. Observing the small retractile slow movements of the flaccid penis and recording the SCA may be a useful indirect method to characterize cavernosal neural innervation and smooth muscle activity.