Corpus Cavernosum Electromyography with Revised Methodology: An Explorative Study in Patients with Erectile Dysfunction and Men with Reported Normal Erectile Function

Abstract

Introduction A lack of standardization of the recording techniques of corpus cavernosum electromyography (CC-EMG) and objective criteria to characterize the recorded signals (CC-potentials) are the main difficulties hindering the clinical application of this method. These difficulties have been recently overcome by revising the recording and interpretation methodology of CC-EMG Aim To assess if CC-EMG performed with the revised methodology is discriminative for well-defined clinical conditions in patients with erectile dysfunction (ED). Methods Based on blinded clinical diagnosis, ED patients were catalogued into five subgroups: severe penile fibrosis, cavernous arterial insufficiency (CAI), cardio-vascular comorbidity (CVCM) without proven CAI, post-radical retropubic prostatectomy (RRP), and psychogenic ED. With four electrodes placed on the penile shaft bilaterally, CC-EMG was recorded monopolarly for 30 minutes during flaccidity. After evaluation of the recordings by visual inspection, CC-potentials were analyzed using cross- and autocorrelation techniques. The parameters evaluated were amplitude, duration, dominant frequency (DF), and maximum cross-correlation coefficient (Rmax) of CC-potentials recorded from proximal and distal parts of the CC. Main Outcome Measures Comparison of the values of parameters amplitude, duration, DF, and Rmax between patient and control groups. Results A total of 119 patients with ED and 43 men with reported normal erectile function were studied. Thirteen out of 14 patients with severe penile fibrosis did not show any distinguishable CC-potential. Patients with CAI had significantly decreased amplitude compared with the potent controls, as well as the patients with CVCM but without proven CAI. Significantly decreased amplitude and Rmax were detected in ED patients following RRP compared with the controls. Conclusion Corpus cavernosum electromyography performed with the revised methodology is able to discriminate ED patients with conditions that are associated with cavernous smooth muscle degeneration and/or autonomic neuropathy from men with reported normal erectile function.

Voltage-Dependent Ca2+ Currents Contribute to Spontaneous Ca2+ Waves in Rabbit Corpus Cavernosum Myocytes

“…The fact that inhibitors of L-type VDCC inhibit spontaneous contractions in isolated strips of corpus cavernosum is consistent with the idea that Ca 2+ influx via this pathway is important for tone generation [1,2,7,8]. However, the ability of human, rabbit and rat corpus cavernosum to develop phasic contractions and phasic electrical activity (such as bursting activity in electromyography studies, spontaneous depolarizations, and spontaneous Ca 2+ -activated Clcurrents) suggests that the intracellular Ca 2+ levels are oscillatory, rather than constant as described by the "window current" mechanism [1,2,[9][10][11][12][13][14][15]. This was confirmed in a recent study where spontaneous Ca 2+ waves were shown to be generated both in individual smooth muscle cells and across intact slices of corpus cavernosum tissue where bursts of Ca 2+ signals could be seen to trigger both phasic and tonic components of contraction [15].…”

Standard Operating Procedures for Neurophysiologic Assessment of Male Sexual Dysfunction

“…It has recently been proposed after radical prostatectomy that impairment of penile thermal and vibratory sensory thresholds could reflect cavernous nerve damage. Further studies are mandatory to confirm this finding .…”

Electrophysiologic Activity of the Tunica Albuginea and Corpora Cavernosa: Possible Role of Tunica Albuginea in the Erectile Mechanism

“…The recording of the electric activity of the CC, or the electrocavernosogram (ECG), was introduced in the diagnostic evaluation of erectile dysfunction [8][9][10][11][12][13][14][15]. It provides information on the smooth musculature and autonomic innervation of the penis.…”