Cavernous Electrical Activity Research Articles

Corpus Cavernosum Electromyography Revisited: Defining the Origin of the Signal

We performed this study to identify the source of complexes recorded during corpus cavernosum electromyography. A total of 10 healthy male volunteers 19 to 54 years old (mean age 36) with normal erectile function, participated in the study. A Porti electrodiagnostic system (TMS International, Enschede, The Netherlands) connected to a notebook computer recorded low frequency corpus cavernosum electromyography complexes via penile surface electrodes in 3 phases. In phase 1 baseline corpus cavernosum electromyography was recorded for 30 minutes. In phase 2 penile skin block was performed followed by 30 minutes of corpus cavernosum electromyography recording. Phase 3 consisted of intracavernous block followed by corpus cavernosum electromyography recording for 30 minutes. During all 3 phases startling auditory stimuli and median nerve stimulation were used at random intervals to evoke a sympathetic nervous system response. A suprapubic electrode was used as a control to record sympathetic electrodermal activity. In phase 1 all subjects had spontaneous and evoked corpus cavernosum complexes. The penile skin block used in phase 2 did not affect the presence of these complexes, which remained present in all subjects. During phase 3 no spontaneous or evoked corpus cavernosum complexes were recorded in any subjects, indicating that the intracavernous block eliminated the corporally generated signal. All subjects in all 3 phases demonstrated a sympathetic electrodermal response in the suprapubic electrode in response to evoking stimuli. This study confirms the penile cavernous tissue, and not the penile skin or surrounding tissue, as the origin of the corpus cavernosum electromyography complex. Further refinement of this technique may render it useful in the evaluation of neurogenic and myogenic erectile dysfunction.

Relaxation degree of cavernous smooth muscle: a novel parameter to predict postoperative success in penile revascularization

To investigate the role of a new preoperative parameter, relaxation degree (RD), in the prediction of postoperative success after deep dorsal vein arterialization operations. Chart reviews and electromyographic recordings were evaluated in 52 patients on whom deep dorsal vein arterialization was carried out for pure caverno-occlusive dysfunction. The efficiacy of the operation was assessed as improvement or failure according to the five-item version of international index of erectile function (IIEF). RD was defined as the percentage decrease in cavernous electrical activity (CEA) after intracavernous papaverine injection. Preoperative RD measurements were statistically compared between the improvement and the failure groups. The mean age of patients was 34.2 +/- 8.1 years (range 25-49) with a mean follow-up of 32 +/- 8 months. Improvement was observed in 39 (75%) and failure in 13 (25%) patients. The mean RD values were 60% and 32% for surgical improvement and failure groups respectively (P < 0.01). In patients with mild ED, the mean RD value was 70.3% whereas it was 28.7% in patients with severe ED. The RD value of greater than 40% predicts surgical success with a specifity of 75% and a sensitivity of 90%. The RD value of cavernous muscle seems to decrease as the severity of ED increases. In addition, RD may predict the outcome of penile revascularization operations and it may be a useful preoperative indicator for surgical success.

Effects of transanal pelvic plexus stimulation on penile erection: clinical implications

To determine the ability of transanal pelvic plexus stimulation (TPPS) in inducing penile tumescence in patients with non-neurogenic erectile dysfunction (ED) and to compare the erection degree with papaverine-induced erection. The cavernous electrical activity (CEA) in 21 men with non-neurogenic erectile dysfunction was measured during TPPS by electromyography of corpus cavernosum and the erection degree of penis (flaccid, semi-rigid, rigid) was noted. The stimulation amplitude was increased from 20 to 100 mA. All patients also underwent intracavernous papaverine injection and further CEA recordings were obtained. Twelve and nine patients were diagnosed with vasculogenic (VED) and non-vasculogenic ED (NVED), respectively. TPSS led to a penile erectile response in 12 patients (57%), whereas papaverine injection caused erection in 16 (76.2%) patients. The mean baseline CEA (16.9 +/- 9.1 mV) did not change with TPPS, but papaverine significantly decreased the mean CEA to 12.3 +/- 4.9 mV (P < 0.001). CEA recordings of 16 (76.2%) patients revealed a significant decrease after papaverine injection, however seven (33.3%) patients showed significant CEA decrease in response to TPPS. Both TPPS and papaverine were observed to have a higher effect in patients with NVED in terms of inducing penile erection and decreasing CEA compared to their effects in patients with VED. TPPS induces penile erection and decreases CEA for some extent, but to a lesser degree compared to papaverine. As further improvements are achieved in the methodology of TPPS, it may be a valuable method in the evaluation patients with erectile dysfunction.

Caverno-Occlusive and Autonomic Dysfunction: A New Concept in Young Patients

We attempted to identify the etiology of erectile dysfunction in 50 male patients with a mean age of 31.4 (25–42) years. The physical and neurological examinations, history, biochemistry and serum testosterone and prolactin levels were within normal limits. Pharmacopenile duplex ultrasonography, corpus cavernosum electromyography (CC-EMG) and cavernosometry were performed. Smooth muscle tone and the relaxation response after intracavernous papaverine and sodium nitroprusside injections were evaluated by CC-EMG. Autonomic dysfunction has been defined as increased electrical activities after visual sexual stimulation and lowered amplitudes despite normal smooth muscle content. Our definition is similar to this: paradoxically increased electrical activities after intracavernous injection. Caverno-occlusive dysfunction (COD) and accompanying pathologies were found in 38 patients (76%) with pure COD in 26 (52%), COD and arterial pathology in 2 (4%) and COD + autonomic dysfunction in 10 patients (20%). Amplitudes of cavernous electrical activity were low in 32 of 38 patients with COD. These high COD and autonomic dysfunction rates led us to examine these pathologies on molecular and electrophysiological bases.

Progress in corpus cavernosum electromyography (CC-EMG)-third international workshop on corpus cavernosum electromyography (CC-EMG).

Corpus cavernosum electromyography (CC-EMG) is currently used in most European centres dealing with erectile dysfunction, both on account of experimental applications and the early findings of clinical results. In this particular field, experimental research and clinical practice, on selected patients, have been elaborated in parallel, revealing the relationships between cavernous electrical activity and the integrity of autonomic ortho- and parasympathetic nervous systems of the genital organs. A relationship has also been demonstrated between the functional status of the cavernous smooth muscle and cavernopathies, which, at present, cannot be evaluated with the other diagnostic methods currently available. The first Workshop on CC-EMG was held in Mannheim, Germany, in 1993 and this represents a true milestone in this particular field. It was on that occasion that the denomination (CC-EMG) and the standardization of the technique were decided upon by the pioneers of electromyographic studies 1 .I n fact, during the consensus meeting, the main technical and clinical parameters were established in order to obtain homogeneous recordings and comparable results between different Centres. During the second Workshop, held in Hannover, Germany in 1994, the range of electrical recordings from homogeneous series of normal patients have been established on the basis of analogic methods of tracing and interpretation. Moreover, the early recordings employing conversion and digital analy

Corpus cavernosum electromyography (CC-EMG): a new technique in the diagnostic work-up of impotence.

We have studied cavernous electrical activity in 42 subjects, healthy volunteer controls and groups of impotent patients using a nonspecific electromyographic device (PICO-MENFIS) and a specific one, the SPACE-recorder 7500 designed to achieve electric recordings from the corpora cavernosa. In all of the patients, we detected under basal conditions a mean amplitude of 583 +/- 323 microV, a mean duration of 4.9 +/- 7 s, a mean polyphasicity of 3.5 +/- 1.4. It should be emphasized that a significant reduction of potential amplitudes was recorded after pharmacological stimulation in both the controls and the impotent patients. The healthy controls showed amplitudes significantly higher than the impotent patients after radical cystectomy (715 +/- 141 microV versus 381 +/- 227 microV, p < 0.01). The patients after a "nerve-sparing" radical cystectomy with a mean amplitude similar to the controls (500-700 microV) reacted well to the intracavernous drugs in a high percentage of cases. In our experience, CC-EMG seems to be a reliable method which can pinpoint directly lesions to the cavernous smooth muscle and penile autonomic nerves. It has also been able to assess the effects of stress, anxiety and pain on the erectile mechanisms.

Early experience of corpora cavernosa electromyography in impotent patients after radical cystoprostatectomy.

To assess the effects of autonomic nerve damage on the basis of cavernous electrical changes. A study was carried out on the cavernous electrical activity in healthy volunteers (controls) and impotent patients after radical cystoprostatectomy using a specific electromyographical device, the 'SPACE-recorder 7500'. A significant reduction in the amplitude of potentials was recorded after pharmacological stimulation in both the controls and impotent patients. The healthy controls showed amplitude values which were significantly higher than the impotent patients after radical cystectomy (715 +/- 141 vs. 381 +/- 227 microV, p < 0.01). After 'nerve-sparing' radical cystectomy with a mean amplitude similar to controls (500-700 microV), the patients showed rigid erections after injection of intracavernous drugs in a high percentage of cases. In our experience, corpora cavernosa electromyography seems a reliable method which can directly point out damage in the cavernous smooth muscle and the penile autonomic nerves.

Prognostic Factors for the Postoperative Outcome of Penile Venous Surgery for Venogenic Erectile Dysfunction

Since penile venous surgery is usually associated with a poor postoperative outcome, a study was done to evaluate possible prognostic factors for this procedure. A total of 77 patients with erectile dysfunction underwent ligation of all dorsal penile veins and resection of the deep dorsal penile vein for venous incompetence. In all patients a comprehensive evaluation was done preoperatively. All patients did not respond to pharmacotherapy and had a venous leak. After a followup of 6 months, patients were classified as having full spontaneous erections, failure and response to pharmacotherapy. Of the 77 patients 31 (40.3%) had full spontaneous erections, 8 (10.3%) were currently responding to pharmacotherapy and 38 (49.4%) failed. The maintenance flow was 75 ± 45ml. per minute in the group with spontaneous erections and 103 ± 60ml. per minute in the failure group (p = 0.20). Mean patient age was 49.8 ± 11.7 and 49.1 ± 10.2 years, respectively (p = 0.23). Of the 41 patients with normal single potential analysis of cavernous electrical activity 28 had full erections postoperatively, 5 responded to pharmacotherapy and 8 failed, compared to 3, 3 and 30, respectively, of the 36 patients with abnormal single potential analysis of cavernous electrical activity. After a mean followup of 21 months (range 6 to 47 months), 4 patients with full erections at 6 months postoperatively currently require intracavernous pharmacotherapy. Our results indicate that single potential analysis of cavernous electrical activity seems to be an important prognostic factor for the postoperative outcome of penile venous surgery for venogenic impotence.

Single Potential Analysis of Cavernous Electrical Activity in Spinal Cord Injury patients

Introduced in 1988, cavernous electromyography and its evolution, single potential analysis of cavernous electrical activity (SPACE), seem to be promising diagnostic methods in the evaluation of erectile dysfunction. The aim of our study was to determine the influence of a centrally disturbed autonomic supply on SPACE recordings. SPACE was performed in 35 male patients with complete and 2 with incomplete spinal cord lesions at a cervical or thoracic level. Simultaneous recording was done with concentric needle electrodes in both cavernous bodies with a frequency range of 0.5 to 100Hz. All patients underwent a full neurological and urological evaluation, including cystometry. The lesion was cervical in 12 patients and thoracic in 22. Three patients underwent sacral deafferentation and bladder pacemaker implantation. One of 12 patients with cervical and 10 of 22 with thoracic lesions reported full rigid reflexogenic erections, while 3 of 12 patients with cervical lesions were not evaluable due to grounding failure.Of these patients 31 were eligible for our study. No patient had an entirely normal SPACE. Four of 9 patients with cervical and 19 of 22 with thoracic lesions had a normal, silent basic electric (less than 5 μν.) oscillation, while the remainder had a baseline oscillation of up to 100 μν. Normal potentials were found in 2 of 9 and 10 of 22 patients, respectively. Low frequency, high amplitude potentials were found in 6 of 9 and 21 of 22 patients, respectively, while low frequency, low amplitude potentials occurred in 8 and 8, respectively, and high frequency potentials occurred in 5 and 1, respectively. Our results show that abnormal autonomic input induces abnormal SPACE findings in patients with (presumably) normal cavernous tissue.

Letter to the Editor. Re: single potential analysis of cavernous electrical activity in spinal cord injury patients.

Letter to the Editor. Re: single potential analysis of cavernous electrical activity in spinal cord injury patients.

Predictive Value of Real-Time Rigiscan Monitoring for the Etiology of Organogenic Impotence

We performed routine diagnostic evaluations in 160 consecutive patients from our impotence clinic. After the diagnostic studies were completed, the results of RigiScan**Dacomed, Minneapolis, Minnesota. monitoring during visual sexual stimulation before and after intracavernous injection of vasoactive drugs were compared to the results of standardized pharmacological testing, single potential analysis of cavernous electrical activity and pharmacocavernosometry. The results suggest RigiScan monitoring to be a highly accurate method to evaluate and document objectively the erectile response after intracavernous injection of vasoactive drugs. Although pathological monitoring after intracavernous injection is significantly associated with pathological findings in the specific evaluation, the predictive value of RigiScan monitoring for specific organogenic etiologies is not satisfactory, since normal monitoring showed no convincing correlation to single potential analysis of cavernous electrical activity or cavernosometry.

Single Potential Analysis of Cavernous Electrical Activity

Since the recent introduction of cavernous electromyography by Gerstenberg and Wagner, a new too for the study of erectile dysfunction in man is available. The refinement of this method, single potential analysis of cavernous electrical activity (SPACE), offers a straightforward approach to the diagnosis of cavernous autonomic neuropathy and smooth muscle myopathy by minimal invasive means. SPACE was done in more than 500 consecutive patients with erectile dysfunction and in 85 normal control subjects. With increasing experience the methodology was refined with respect to the used hardware as well as cut-off frequencies. In normal control subjects, SPACE showed a reproducible regular activity with potentials of low frequency and electrical silence inbetween. The potentials were synchronous throughout the cavernous bodies. In patients with peripheral autonomic denervation, asynchronous potentials with higher frequencies and irregular shape were found. Normal and abnormal potentials were found in patients with upper spinal cord lesions. Recordings obtained with surface electrodes showed similar characteristics when compared with recordings obtained with needle electrodes. Recent studies show that SPACE provides independent information about the autonomic and myogenic intactness of the cavernous tissue. Currently, a computerized expert system and a graded classification for easier interpretation is being developed with first results. We conclude that cavernous electrical activity can be recorded. SPACE is a reproducible diagnostic tool for erectile dysfunction.

The Influence of Anterior Root Stimulation (S2) in Deafferented Spinal Cord Injury Men on Cavernous Electrical Activity

Registration of cavernous electrical activity (single potential analysis of cavernous electrical activity) was recently suggested for the diagnosis of autonomic cavernous dysfunction. For validation of this method the effect of sacral neurostimulation on cavernous electrical activity was examined. In 3 male patients with a complete spinal cord lesion (T3, T4 and T12, respectively), deafferentation was done at the S2 to S5 levels. Around the anterior roots of S2 to S5 electrodes for neurostimulation were placed. Cavernous electrical activity was recorded with an intracavernous needle electrode and with surface electrodes in the flaccid as well as in the erect states induced by neurostimulation (at 7, 8, 12, 18, 20, 30 and 45Hz., 30v. and 0.4msec.). In all patients similar potentials compared to the normal values, as well as additional pathological potentials were recorded during flaccidity. During neurostimulation all patients achieved full erection with no or markedly decreased cavernous electrical activity to frequencies of 12, 18, 20 and 30Hz., while to 7, 8 and, more pronounced, 45Hz. only partial erection with ongoing cavernous electrical activity was found. Our study strongly suggests that cavernous electrical activity and, subsequently, the cavernous smooth muscle tone are dependent on autonomic input. This finding supports the hypothesis that single potential analysis of cavernous electrical activity may be valid in the diagnosis of cavernous autonomic dysfunction. Furthermore, our results suggest a possible role for single potential analysis of cavernous electrical activity in the fine tuning of erection inducing neurostimulators.

Transcutaneous Registration of Cavernous Smooth Muscle Electrical Activity: Noninvasive Diagnosis of Neurogenic Autonomic Impotence

Registration of cavernous electrical activity was shown to be a possible method for the evaluation of cavernous autonomic innervation. Recent studies in patients with normal erectile function showed that cavernous electrical activity is synchronous throughout the entire cavernous bodies. Therefore, we examined the feasibility of transcutaneous registration of cavernous electrical activity in 8 normal and 62 impotent patients. In the sitting patient cavernous electrical activity was recorded with a 2-channel electrophysiological unit. Recording was done with a coaxial needle electrode in the proximal left cavernous body and with surface electrodes bilaterally on the penile shaft. In 7 of 8 normal patients swelling of the penile shaft after circumcision resulted in a dramatically decreased amplitude of the potentials. In 41 of 62 impotent patients recordings were similar. In 10 of 62 patients no recording or markedly decreased amplitudes were noted with the surface electrodes and in these patients a small penis or penile retraction with consecutive electrode displacement was found. Careful repositioning of the surface electrodes with the patient in the supine position resulted in similar recordings in 9 (inconsistently in 4). In 11 of the 62 patients more information was obtained with the surface than with the needle electrode. Our results show that recording of cavernous electrical activity can be done in a completely noninvasive manner using surface electrodes with similar or even better information obtained than with needle electrodes.

Calcitonin-Gene-Related Peptide: A Possible Role in Human Penile Erection and its Therapeutic Application in Impotent Patients

A functional study was done to examine a possible role of calcitonin-gene-related peptide in human penile erection and its possible therapeutic applications for patients with erectile dysfunction. In the determination of an effective dosage, 5ng. (2 patients), 50ng. (2 patients), 500ng. (4 patients), 5μg. (4 patients) and 25μg. (7 patients) were injected intracavernously, and pulse and blood pressure were monitored. Arterial inflow was measured by Doppler sonography, smooth muscle relaxation was determined by the analysis of cavernous electrical activity and cavernous outflow occlusion was recorded by cavernosometry. In 12 patients the erectile response of prostaglandin E1 was compared to the response of an equal (6 patients) or decreased dose of prostaglandin E1 combined with an equal weight of calcitonin-gene-related peptide. In 14 patients the erectile response to the combination of calcitonin-gene-related peptide and prostaglandin E1 was compared to the response of prostaglandin E1 alone, and with a combination of 15mg./ml. papaverine and 0.5mg./ml. phentolamine.Calcitonin-gene-related peptide induced an increase in the penile arterial inflow, cavernous smooth muscle relaxation and cavernous outflow occlusion. Histochemical results indicated nerve fibers positive for calcitonin-gene-related peptide within the cavernous bodies. A dose-dependent erectile response to calcitonin-gene-related peptide was observed at doses of 500ng. to 25μg. Systemic side effects were first observed at a dose of 25μg. in 2 of 7 patients. The combination of calcitonin-gene-related peptide and prostaglandin E1 was more effective in inducing a full erection than either prostaglandin E1 alone or the combination of papaverine and phentolamine. Pain was reported in 4% of the patients who received the combination of calcitonin-gene-related peptide and prostaglandin E1, whereas 42% of those who received prostaglandin E1 alone reported pain. Our results suggest that calcitonin-gene-related peptide may be a possible neurotransmitter for penile erection. A combination of calcitonin-gene-related peptide and prostaglandin E1 seems to be an effective alternative combination in the treatment of impotence.

Single Potential Analysis of Cavernous Electrical Activity in Impotent Patients: A Possible Diagnostic Method for Autonomic Cavernous Dysfunction and Cavernous Smooth Muscle Degeneration

Cavernous electrical activity was recorded in 214 patients with erectile dysfunction and in 39 normal patients. In 34 of the 39 normal patients potentials of a uniform shape were recorded during flaccidity. At cutoff frequencies of 0.5 to 500Hz. the duration was 8 to 18 seconds (mean 12.8 ± 2.8, seconds, standard deviation), the amplitude was 250 to 750 μv. (mean 444 ± 109 μv.) and the polyphasity was 8 to 22 (mean 13.8 ± 3.3). With increasing tumescence and rigidity during audiovisual sexual stimulation, high frequency potentials of low amplitude and short duration were found in the normal patients. In impotent patients with an upper motor neuron or peripheral lesion specific types of potentials were observed. In 11 of 14 impotent patients with insulin-dependent diabetes for more than 20 years and with clinical findings of cavernous myopathy the potentials showed low amplitude, irregular shape and slow depolarizations. Abnormal findings of cavernous electrical activity were recorded in 51.6% of the consecutive impotent patients. Our clinical study suggests that single potential analysis of cavernous electrical activity may be useful in the diagnosis of cavernous autonomic neuropathy and cavernous smooth muscle myopathy.

Single potential analysis of cavernous electrical activity

Recording of cavernous electric activity was performed in 178 patients with erectile dysfunction and in 37 normal patients. In 34/37 normal patients, potentials of a uniform shape were recorded during flaccidity: At cut-off frequencies of 0.5-500 Hz, the length was 8-18 (mean 12.8, SD 2.8), the amplitude 250-750 (mean 444, SD 109) microV, and the polyphasity 8-22 (mean 13.8, SD 3.3). In impotent patients with upper motor neuron lesions or peripheral lesions, specific types of potentials were observed. In 11/14 impotent patients with insulin-dependent diabetes for over 20 years and clinical findings of cavernous myopathy, potentials showed low amplitude, irregular shape, and slow depolarizations. In 51% of the consecutive impotent patients, abnormal findings of cavernous electric activity were recorded. Our clinical study suggests that single potential analysis of cavernous electric activity (SPACE) may be useful in the diagnosis of cavernous autonomic neuropathy and cavernous smooth muscle myopathy.

Standardized Evaluation of Erectile Dysfunction in 95 Consecutive Patients

We investigated 95 patients referred for erectile dysfunction by penile blood pressure measurement, the intracavernous papaverine test and Doppler investigation of the penile arteries. Furthermore, penile cutaneous perception threshold, bulbocavernosus reflex latency and somatosensory cortical evoked potentials of the pudendal nerve were measured. In selected cases cavernosometry, cavernosography and corpus cavernosum electromyography were performed. Doppler investigation of the cavernous arteries after papaverine injection was more reliable than penile blood pressure measurement in the diagnosis of arteriogenic erectile dysfunction. Decreased sensibility of the penis may be the sole factor responsible for inability to sustain an erection. Erectile dysfunction may be provoked by impaired function of the pudendal nerve. Penile cutaneous perception threshold measurement and corpus cavernosum electromyography are mandatory in the evaluation of neurogenic etiology. Cavernosometry and cavernosography are reliable methods in the determination of abnormal drainage from the corpus cavernosum.