Role of penile electrodermal activity in the evaluation of autonomic innervation of corpus cavernosum

Electrophysiological evaluation of alterations in penile sensation due to penile prosthesis implantation in patients with erectile dysfunction

Objective

The present study was aimed to determine the effect of penile prosthesis implantation (PPI) surgery on penile sensation by evaluating the penile electromyography (EMG) variables.

Methods

The research was designed as a prospective study. Thirty patients who were diagnosed with organic erectile dysfunction and had underwent PPI surgery between January 2017 and January 2018 in the Urology Clinic of Antalya Training and Research Hospital were included in this study. Penile sensory EMG was performed on each patient 1 day prior to the surgery by the Physical Therapy and Rehabilitation clinic. Additionally, the control EMG study was also performed in the 3rd and 6th postoperative months.

Results

We included 27 patients in this study who attended regular follow-ups and had complete EMG results. Out of the 27 patients, 23 (85.2%) patients had received malleable (ProMedon) penile prosthesis, one (3.7%) patient had received a two-piece inflatable (Ambicor) penile prosthesis, and three (11.1%) patients had received a three-piece inflatable (AMS 700 CXR) penile prosthesis. The mean nerve conduction value (NCV) of the patients was 29.85 (standard derivation: 22.54; range: 0-78.4) m/s during the preoperative period, whereas it was 27.64 (standard derivation: 24.72; range: 0-83.3) m/s in the 3rd postoperative month and 24.80 (standard derivation: 22.31; range: 0-88.4) m/s in the 6th postoperative month. There was no significant difference between preoperative NCV and 3rd postoperative month NCV (p=0.607). Similarly, no significant difference was observed between preoperative NCV and 6th postoperative month NCV (p=0.276). Additionally, the change between NCV values at postoperative 3rd and 6th months was not statistically significant (p=0.553).

Conclusion

Significant loss of penile sensation does not occur in patients who undergo PPI surgery.

Measurement of electrochemical conductance of penile skin using Sudoscan®: A new tool to assess neurogenic impotence

OBJECTIVES

To investigate the value of electrochemical skin conductance (ESC) measurement at penile level using Sudoscan^® for the diagnosis of neurogenic impotence in diabetics.

METHODS

The following neurophysiological parameters were assessed in 25 male diabetics who complained of impotence and 25 age-matched normal male subjects without erectile dysfunction (age range: 29-70 years): ESC, sympathetic skin responses (SSR), warm detection thresholds (WDT), and cold detection thresholds (CDT) for the penis and the feet, vibration detection thresholds (VDT) for the penis, and sensory nerve conduction study of the dorsal nerve of the penis (DNP) with sensory nerve action potential (SNAP) recording.

RESULTS

Diabetic patients with impotence differed from controls with regard to most neurophysiological results at both penile and foot levels. Among penile innervation variables in the group of impotent diabetics, penile ESC was found to be the most frequently abnormal (80% of patients), followed by penile WDT, CDT, and DNP-SNAP amplitude (52% of patients), and then penile SSR amplitude and VDT (44% of patients). Various combinations of abnormalities were observed: penile ESC was the only abnormal test in 2 patients, while all tests were abnormal in 2 patients and remained normal in only one patient.

CONCLUSION

Erectile dysfunction is common in diabetic men, but the diagnosis of a neurogenic origin is challenging. This study showed that ESC measurement using Sudoscan^® is feasible and more sensitive than SSR recordings to show penile sympathetic innervation impairment. This new test should be further studied to better define its diagnostic accuracy and clinical correlates.

Arousal, working memory capacity, and sexual decision-making in men

This study investigated whether working memory capacity (WMC) moderated the relationship between physiological arousal and sexual decision making. A total of 59 men viewed 20 consensual and 20 non-consensual images of heterosexual interaction while their physiological arousal levels were recorded using skin conductance response. Participants also completed an assessment of WMC and a date-rape analogue task for which they had to identify the point at which an average Australian male would cease all sexual advances in response to verbal and/or physical resistance from a female partner. Participants who were more physiologically aroused by and spent more time viewing the non-consensual sexual imagery nominated significantly later stopping points on the date-rape analogue task. Consistent with our predictions, the relationship between physiological arousal and nominated stopping point was strongest for participants with lower levels of WMC. For participants with high WMC, physiological arousal was unrelated to nominated stopping point. Thus, executive functioning ability (and WMC in particular) appears to play an important role in moderating men's decision making with regard to sexually aggressive behavior.

Clinical autonomic neurophysiology and the male sexual response: an overview

INTRODUCTION

Clinical neurophysiology is the study of the human nervous system through the recording of bioelectrical activity. In the realm of male sexual functioning, this includes using electrophysiologic techniques to study the nerves subserving erection, emission, ejaculation, and orgasm.

AIM

To introduce the reader to the principles of clinical neurophysiology as they relate to the male sexual response, particularly erection.

METHODS

We review the pertinent autonomic neuroanatomy and neurophysiology of reflexes relevant to the male sexual response, as well as summarize the genital electrodiagnostic tests that are being used to interrogate the autonomic innervation pertinent to male sexual functioning.

CONCLUSIONS

The male sexual response is a coordinated series of interactions between the somatic and the autonomic nervous systems. Measurement of the autonomically mediated portions of the sexual reflexes is of great clinical interest, particularly in relation to erection. Advances in clinical electrodiagnostics now allow for consistent recording of evoked and spontaneous intrapenile electrical activity. However, before broad and widespread use of these techniques is possible, more investigations are needed.