Evaluation of erectile dysfunction with continuous monitoring of penile rigidity

Measurement of nocturnal penile tumescence or circumferential expansion is a valuable method for the diagnosis of erectile impotence. However, only a few investigations have been made of penile rigidity during tumescence with a single isolated measurement. A new method of continuous and simultaneous recording of nocturnal penile rigidity and circumferential expansion (tumescence) was used in 105 patients with erectile impotence. The method provided several findings concerning nocturnal penile erection. Circumferential expansion was not always accompanied by penile rigidity. A dissociation of rigidity between the tip and base of the penis was observed in some patients. Shortened episodes and low amplitude of rigidity also were seen. Of 11 patients with psychogenic impotence diagnosed by conventional methods 3 (27.3 per cent) showed abnormal nocturnal rigidity and 8 of 94 (8.5 per cent) with organic impotence diagnosed by conventional methods showed normal nocturnal rigidity. Because of its ambulatory character the continuous measurement of nocturnal penile rigidity is of value in defining features of nocturnal penile erection and differentiating psychogenic from organic impotence.     

Sildenafil improves nocturnal penile erections in organic impotence.

We studied the effects of sildenafil on nocturnal penile erections. We prospectively evaluated 36 patients with organic or psychogenic impotence and 5 normal, potent men. All patients completed 3 sessions of consecutive nights using the RigiScan Plus device. The first two nights the patients were asked to take placebo before the session and to take 50 mg of sildenafil before the third session. In the organic impotence group the use of sildenafil induced a significant improvement in time of rigidity 60-100%, rigidity and tumescence activity unit values and rigidity and tumescence activity unit values per hour in the tip and base. In the psychogenic impotence group it caused significant improvement only in rigidity activity unit per hour in the tip. In the potent men, changes were statistically insignificant. Sildenafil improves nocturnal penile erectile activity in organic impotence. Our study shows that phosphodiesterase inhibitors can improve penile erections not induced by sexual stimulation.     

Comparison of penile duplex ultrasonography with nocturnal penile tumescence monitoring for the evaluation of erectile impotence

A total of 50 patients with erectile dysfunction underwent comprehensive evaluation, including vascular evaluation with penile duplex ultrasonography and papaverine injection, as well as nocturnal penile tumescence monitoring. The latter was performed in a sleep laboratory setting in all patients. The results of penile duplex ultrasonography with papaverine injection were classified as 18 patients with normal vascular findings, 22 with arterial insufficiency, 3 with the pelvic steal syndrome and 7 with isolated venous leakage. Of the patients 15 had normal ultrasonographic and nocturnal penile tumescence findings, 29 had abnormal ultrasonographic vascular and nocturnal penile tumescence findings, 3 had abnormal ultrasonographic vascular findings and normal nocturnal penile tumescence (including 1 with the pelvic steal syndrome as evidenced by penile brachial index) and 3 had normal ultrasonographic vascular findings and abnormal nocturnal penile tumescence (including 2 with neurogenic erectile dysfunction). Penile duplex ultrasonography with papaverine injection appears to be a useful objective method to evaluate vasculogenic impotence and to correlate favorably with nocturnal penile tumescence monitoring. It also may have a higher yield than nocturnal penile tumescence monitoring in patients with the pelvic steal syndrome. While nocturnal penile tumescence is impaired in patients with neurogenic impotence, penile duplex ultrasonography with papaverine injection reveals, as expected, normal findings in patients with neurogenic impotence and normal vascular systems.     

New concept parameters of RigiScan in differentiation of vascular erectile dysfunction: Is it a useful test?

BACKGROUND: The aim of this study is to investigate the value of new nocturnal penile tumescence recording parameters, such as tumescence activity unit and rigidity activity unit values, total erection number and erection times, in differentiating between psychogenic erectile dysfunction and organic erectile dysfunction. We also aimed to determine the role of these parameters in differentiating arterial erectile dysfunction from veno-occlusive dysfunction. METHODS: Eighty-seven consecutive patients were allocated into three groups as psychogenic, arterial and venous erectile dysfunction after investigations. Nocturnal penile tumescence recording parameters between psychogenic and vascular erectile dysfunction and arterial and veno-occlusive dysfunction were compared. Mann-Whitney U-test, Pearson's chi2 test and correlation coefficient tests were used for statistical analysis. RESULTS: Depending on intracavernous injection, penile Doppler ultrasonography and cavernosometry tests, 37 patients (43%) had psychogenic impotence while 50 (57%) had organic pathologies. Of the 50 patients diagnosed with vascular impotence, 29 (48%) had arterial failure and 21 (42%) had veno-occlusive dysfunction. Nocturnal penile tumescence recording revealed psychogenic erectile dysfunction in 34 patients (39%) and vascular erectile dysfunction in 53 patients (61%). Nocturnal penile tumescence recording has been regarded as the gold standard and, in our series, it showed 90.6% sensitivity and 88.2% specificity in differentiating the cause of erectile dysfunction. Values of rigidity activity unit and tumescence activity unit were significantly higher in patients with psychogenic impotence (P < 0.001), when compared with vascular impotence. In patients with a vascular cause, no difference was found between arterial failure and veno-occlusive dysfunction with regard to tip tumescence activity unit, base tumescence activity unit, tip rigidity activity unit, base rigidity activity unit and erection time (P > 0.001). However, patients with arterial failure had less erection than patients with veno-occlusive dysfunction (P < 0.001). CONCLUSION: New recording parameters of nocturnal penile tumescence can differentiate organic and psychogenic erectile dysfunction more precisely. However, these recording parameters cannot distinguish subgroups with a vascular cause of erectile dysfunction.     

Reproducibility in monitoring nocturnal penile tumescence and rigidity.

The evaluation of sexual dysfunction has improved with the advent of methods to test nocturnal penile tumescence that also monitor penile rigidity. Earlier techniques may not have recorded abnormal rigidity despite normal tumescence. To test the reproducibility of penile tumescence and rigidity, the results of initial and repeat tracings performed a mean of 39 days apart were compared in 17 patients (median age 62 years). Three nocturnal patterns were identified. 1) Among the 17 patients the initial penile tumescence and rigidity pattern was reproduced on repeat testing in 15. 2) Patterns that were not reproduced in the other 2 patients were explained by the ingestion of alcohol or because of a febrile illness during the period monitored. 3) Nocturnal penile rigidity and tumescence tracings from these patients reproduced previous patterns. Monitoring of nocturnal penile tumescence and rigidity is a useful and reproducible tool in the evaluation of male sexual dysfunction.     

New methods in the diagnosis of impotence: RigiScan® penile tumescence and rigidity monitoring and diagnostic papaverine hydrochloride injection

Summary In 26 patients with erectile impotence and 8 healthy volunteers the value of continuous monitoring of penile tumescence and rigidity by means of the RigiScan was tested. Based on history and routine screening tests the patients were divided into 3 groups of preliminary diagnosis: psychogenic (5 patients), organic (10 patients), mixed (11 patients). Real-time measurements of tumescence and rigidity were performed during direct visual stimulation and after intracorporeal injection of 80 mg papaverine hydrochloride according to a specific protocol. A total of 21 patients were monitored during sleep studies for 2 or 3 consecutive nights. The rigidity figures of the volunteers correlated well with their subjective interpretation of the erection. Evaluation of the recordings of the impotent patients enabled reclassification of the mixed group into 3 patients with mainly organic and 8 patients with mainly psychogenic impotence. RigiScan recording of penile tumescence and rigidity appears to be of great value in the diagnosis of impotent patients. Real-time monitoring during direct visual stimulation and after papaverine injection can generally replace nocturnal measurements. If the patient shows a positive response on visual sexual stimulation (VSS) alone, then his impotence is of psychogenic origin. Failing rigidity during VSS after injection indicates vascular impotence. In patients who show negative results during VSS alone, and positive response after injection or during subsequent VSS, nocturnal monitoring will differentiate between psychogenic and neurogenic impotence.     

Environmental agents and erectile dysfunction: a study in a consulting population

We evaluated chemical and physical environmental agents as risk factors for erectile dysfunction among a consulting population. We studied 199 men who sought medical help for erectile disorders between 1996 and 1998 in 3 andrology units in the Litoral Sur region of Argentina. Patients were evaluated by monitoring nocturnal penile tumescence and rigidity, and were classified as having normal (n = 26), irregular (dissociation, short episode or low amplitude, n = 146), or flat erectile pattern (n = 26). Exposure to environmental agents was assessed by a detailed interview, and 4 groups were constituted: nonexposed, pesticide-exposed, solvent-exposed, and heat-exposed. A multivariate polytomous logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for association between quality of nocturnal erections and exposure groups adjusted for confounding factors. Exposure to environmental agents was a risk factor for a flat erectile pattern (OR 7.1, 95% CI 1.5-33.0 for pesticides; OR 12.2, 95% CI 1.2-124.8 for solvents; and OR 1.7, 95% CI 0.3-9.4 for heat). Associations were much weaker for an irregular erectile pattern (OR 1.8, 95% CI 0.5-6.7 for pesticides; OR 2.1, 95% CI 0.3-17.9 for solvents; and OR 1.2, 95% CI 0.4-4.0 for heat). Our results suggest that environmental agents constitute a risk factor for erectile dysfunction by interfering with erectile ability.     

Relationship between perineal muscle contractions, penile tumescence, and penile rigidity during nocturnal erections

The mechanism of penile erection and erectile dysfunction is still unclear and widely debated. The role of the perineal muscles in the erectile process, especially in changes in intracavernous pressure, is increasingly being studied on the hypothesis that perineal muscular contractions are essential to full penile rigidity. In a previous investigation we studied the correlation between voluntary perineal muscle contractions and intracavernous pressure during artificially induced erections. The purpose of the current study was to examine whether under normal conditions of nocturnal erection a similar relationship exists between the electromyographic activities of perineal muscles and changes in penile rigidity. Nocturnal penile recordings were made of seven volunteers with psychogenic erectile dysfunctions. During nocturnal erections simultaneous computerized recordings were made of penile tumescence, penile rigidity, and electromyographic activities of perineal muscles. The peaks for the three variables were reached simultaneously. The results of this study suggest the existence of two different physiologic phases: a vascular phase and a muscular phase. Furthermore, in cases of dysfunctions, specific diagnostic assessment and therapeutic management will be required for both penile tumescence and penile rigidity.     

Nocturnal penile tumescence predicting response to intracorporeal pharmacological erection testing

Although response to intracorporeal pharmacological erection testing has been proposed to determine the etiology of impotence, physiological criteria predicting this response have not been established and the literature includes conflicting results regarding which patients respond to pharmacological erection therapy. In this study 37 impotent patients underwent a diagnostic nocturnal penile tumescence evaluation (including measurements of rigidity, pulsations and bulboischiocavernosus muscle activity) and the results were correlated with subsequent response to intracorporeal pharmacological testing. Most but not all patients with psychogenic impotence and all with neurogenic impotence responded with good erections. For vasculogenic impotence response rate depended upon impairment severity determined from nocturnal penile tumescence measurements; none of the severe cases versus 90 per cent of the milder cases responded. The results indicate that response to intracorporeal pharmacological testing does not accurately distinguish psychogenic from organic impotence, is best for neurogenic impotence and worst for severe vasculogenic impotence, and can be predicted accurately by nocturnal penile tumescence measurements.     

Nocturnal penile tumescence activity unchanged after long-term intracavernous injection therapy

PURPOSE: Anecdotal evidence suggests that some men have restored erectile function after long-term intracavernous injection therapy for erectile dysfunction. We objectively assessed this phenomenon using nocturnal penile tumescence testing. MATERIALS AND METHODS: In our retrospective study 19 men with a mean age of 53.5 years who had organic erectile dysfunction underwent nocturnal penile tumescence testing before and after prostaglandin E1 based intracavernous injection at least 6 months in duration. The nocturnal penile tumescence parameters measured included the number of erectile episodes, base and tip tumescence, and percent of time with rigidity greater than 70% at the penile base and tip. A 5-item questionnaire was given to all patients after the intracavernous injection period to assess subjective changes in erectile quality. RESULTS: Mean time on intracavernous injection was 2.42 years and mean injection frequency was 3.74 times monthly. Prostaglandin E1 only, and combined prostaglandin E1, phentolamine and papaverine were used in 7 and 9 cases, respectively. Nine patients believed that unaided erection improved after intracavernous injection and 6 achieved intercourse without injection who were unable to do so before injection. No statistically significant changes were noted in any of the 5 objectively measured nocturnal penile tumescence parameters. CONCLUSIONS: Long-term prostaglandin E1 based intracavernous injection may provide subjective improvement in erectile function in some men. However, as measured by nocturnal penile tumescence testing, no objective improvement in spontaneous erectile function occurs.     

New method for continuous measurement of nocturnal penile tumescence and rigidity

A new technique for continuous recording of penile rigidity and tumescence has been developed. This methodology has been utilized in initial studies to define erectile function in both normal and impotent males. Accurate recording of tumescence and rigidity have been utilized to document the decline in erectile function associated with organic impotence.     

Quantitative assessment of nocturnal penile tumescence and rigidity in normal men using a home monitor

Current methods now permit the measurement of nocturnal penile tumescence and rigidity (NPTR) in men with erectile dysfunction. But the relationship of rigidity to tumescence and the changes in rigidity with age have not been defined in normal men. Accordingly, the authors assessed NPTR in 47 normal men using a portable, take-home monitor (Rigiscan). Penile tumescence time was found to decrease with advancing age (p less than 0.05), whereas the number of erectile episodes and penile rigidity did not significantly change with age for men in the third through sixth decades (p less than 0.05). Using area-under-the-curve as an integrated measure of amplitude and duration, significant correlations between tumescence and rigidity (p less than 0.001), and between tip and base measurements (p less than 0.001) were found. With these normative data, prospective studies should determine the sensitivity and specificity of various NPTR parameters in the diagnosis of erectile dysfunction.     

Snap-Gauge band versus penile rigidity in impotence assessment

We examined the ability of the Snap-Gauge band to differentiate rigid from nonrigid erections in men complaining of impotence. A total of 80 patients was measured by a Snap-Gauge band and via technician assessment of erectile rigidity while undergoing nocturnal penile tumescence testing. The Snap-Gauge band correctly diagnosed 77.5 per cent of the patients with a sensitivity of 70 per cent and specificity of 80 per cent. The Snap-Gauge band is inexpensive compared to sleep laboratory testing and it is relatively reliable. We conclude that the Snap-Gauge band has a role in impotence assessment and it can function as a screening device in evaluation of this problem.     

The unreliability of nocturnal penile tumescence recording as an outcome measurement in the treatment of organic impotence

We investigated the degree of congruence between outcome measures used to evaluate pharmacological treatment of impotence. After a comprehensive multidisciplinary assessment 17 patients were treated with an adrenergic blocker during an 8-week interval. Nocturnal penile tumescence recordings were made before treatment (as part of the assessment procedure) and at its conclusion. As part of a larger study the use of nocturnal penile tumescence monitoring has been examined as a possible outcome measure. Patient and partner self-reports also were used to evaluate treatment outcome. A comparison of patient and partner self-reports with nocturnal penile tumescence records showed little agreement between the 2 measures. These findings suggest that despite its intuitive appeal as an index of erectile function nocturnal penile tumescence recording is not a reliable index of therapeutic effectiveness. Furthermore, these findings lend support to the hypothesis that nocturnal penile tumescence and sexual erections may be separate phenomena, perhaps under the control of different mechanisms.     

Evaluation of erectile dysfunction in patients with Peyronie's disease

Of 62 hospitalized patients with Peyronie's disease 18 (29 per cent) had abnormal nocturnal penile tumescence studies that were characterized as indicating organic impotence. However, the majority of these patients had some underlying disease or factor other than the plaque itself to explain the altered nocturnal penile tumescence. In only 5 per cent of these patients could the abnormal nocturnal penile tumescence be attributable to the plaque itself. Primary excision of the plaque and dermal grafting improved erectile function in all except a minority of patients who required insertion of a penile prosthesis to alleviate continued erectile impotence. For this reason we do not recommend insertion of a penile prosthesis during plaque excision. The plaque of Peyronie's disease does not appear to impede vascular flow distal to the plaque. However, previous excision may result in altered hemodynamics that can result in erectile impotence.     

NOCTURNAL PENILE TUMESCENCE AND RIGIDITY MONITORING IN YOUNG POTENT VOLUNTEERS: REPRODUCIBILITY, EVALUATION CRITERIA AND THE EFFECT OF SEXUAL INTERCOURSE

Purpose

We studied the reproducibility of nocturnal penile tumescence, rigidity evaluation criteria and the possible effects of sexual intercourse in young, healthy, potent male volunteers.

Materials and Methods

We recruited 12 male medical students 21 to 24 years old into the study. A disorder-free medical history, availability of a sexual partner and normal erectile function were the inclusion criteria. All subjects completed 3 sessions of 3 nights of recording using the RigiScan* device with at least a 3-day interval between recordings. During the last 3-night recording subjects were asked to have sexual intercourse at least once. Analysis of the recordings was focused on the best erectile event as well as on rigidity and tumescence activity units normalized per hour.*UroHealth Systems, Inc., Laguna Niguel, California.

Results

The subjects completed 36, 3-night recordings. Of the total of 108 sessions 18 occurred after sexual intercourse. We analyzed 562 erectile episodes. All 3-night recordings included at least 1 episode of rigidity at the penile tip greater than 60% and more than 10 minutes in duration. Sexual intercourse did not significantly affect nocturnal penile tumescence and rigidity. When rigidity and tumescence activity unit values were normalized by the hour and expressed as mean values of the 3-night sessions, documented values became reproducible.

Conclusions

At least 2 consecutive nights of recording are necessary to evaluate nocturnal penile tumescence and rigidity recordings. Nocturnal penile tumescence and rigidity with at least 1 erectile episode of tip penile rigidity greater than 60% and 10 minutes in duration may be associated with potency. Mean rigidity and tumescence activity unit values per hour of a recording may be used as objective parameters to measure overall erectile activity. In addition, sexual intercourse seems to decrease nocturnal penile tumescence and rigidity measurements, although not statistically significant. We anticipate that application of these criteria for nocturnal penile tumescence and rigidity evaluation will improve the diagnostic validity of the test. Future research will determine whether these criteria are too strict for the evaluation of aging men.     

Intracavernous injections of papaverine and phentolamine: correlation with penile brachial index

Eighty-two patients were evaluated for erectile failure with a comprehensive history, physical examination, hormonal testing, noninvasive Doppler examination (PBI), and nocturnal penile tumescence (NPT). After these studies all patients received intracavernous injection with a combination of papaverine (50 mg) and phentolamine (1.66 mg), and both tumescence and rigidity were monitored. Rigidity response was compared with the PBI. The number of patients with a poor rigidity response in each PBI category were: 3 of 5 with a PBI of less than 0.6 (vasculogenic), 7 of 11 with a PBI of 0.6-0.75 (ambiguous), and 25 of 66 with a PBI of 0.75-1.0 (normal). These results indicate only a marginally significant association between PBI and intracavernous injection. The procedure was safe with no long-term sequelae from injection observed, and no surgical intervention was required. Complications of injections included reversible priapism in 11 patients (13.4%), transient dizziness in 10 patients (12.2%), and hematoma in 5 patients (6.2%). This study suggests that intracavernous injection with a drug combination may be a more sensitive screening test for vasculogenic impotence than noninvasive Doppler studies because it more closely simulates the erectile response.     

Diagnosis of penile erectile dysfunction: simultaneous recording of nocturnal penile rigidity and circumferential expansion]

This paper briefly reviews diagnostic examinations for penile erectile dysfunction and mainly refers to a newly developed ambulatory system of RigiScan which enables simultaneous recording of penile circumferential expansion and rigidity, introducing the latest values of variables of penile tumescence and rigidity in the Japanese without erectile dysfunction.     

Visual sexual stimulation plethysmography: complementary test to nocturnal penile plethysmography

Diurnal penile plethysmography under visual sexual stimulation (VSS) and nocturnal penile tumescence (NPT) plethysmography have been performed in 5 healthy volunteers and 195 consecutive men complaining of impotence. Our study demonstrates that VSS plethysmography may compensate at least partially for the shortcomings of classic NPT plethysmography, by allowing direct clinical estimation of "erectile performance." Twenty percent of the patients had full erection under VSS. These patients do not need further testing. VSS is a noninvasive and useful "first-line" investigation in erectile dysfunction.     

Continuous monitoring of penile rigidity and tumescence in Japanese without erectile dysfunction

Continuous monitoring of penile rigidity and tumescence has been proved to be of use for accurate diagnosis of erectile impotence, since it provides objective recording of penile rigidity as well as circumferential expansion. Prior to clinical use of this procedure in Japan, a study was performed to clarify normal features of nocturnal penile tumescence of Japanese and to ensure safety of this procedure. The subjects consisted of 16 normal volunteers, aged from 24 to 44 years. With fully informed consent of the volunteers, nocturnal penile rigidity and circumferential expansion were simultaneously measured for three consecutive nights by means of RigiScan at the base of the penis (base) and at about five millimeters proximal to the coronary sulcus (tip). The minimum circumference of the penis was 62.7 +/- 4.6 mm (mean +/- SD) at the tip and 65.4 +/- 9.3 mm at the base. The maximum circumference, which meant full erection in the normal volunteers, was 102.5 +/- 14.2 mm at the tip and 108.6 +/- 14.7 mm at the base. The mean duration of tumescence, i.e. circumference expansion more than 10 mm, was 23.0 +/- 6.9 minutes at the tip and 38.3 +/- 12.0 minutes at the base. The mean rate of episodes of circumference expansion more than 10 mm was 0.75 +/- 0.27 per hour at the tip and 0.70 +/- 0.26 per hour at the base. The maximum rigidity lasting more than 10 minutes was 82.9 +/- 10.1% at the tip and 85.4 +/- 8.4% at the base.(ABSTRACT TRUNCATED AT 250 WORDS)