Erectile Dysfunction: What Tests Confirm my Diagnosis?
ED is the persistent inability to achieve and/or maintain an erection that is satisfactory for sexual intercourse. Affecting as many as 1 million Australians, ED affects self-esteem and quality of life. This under-diagnosed condition affects 25% of men aged 40 – 70 years, with the risk of ED being nearly four times higher for men over 60, when compared to the younger age groups. There are many risk factors for ED development, which makes diagnosing ED difficult for healthcare providers (Cohan & Korenman, 2001).
Initial Diagnosis
Medical practitioners will generally ask numerous questions (some of which may seem very personal or invasive), when diagnosing ED. They will also assess health status and may check for other health problems such as high blood pressure or diabetes, as these are linked with ED. A doctor may also carry out a physical examination, sometimes in the form of a digital rectal exam or DRE as this allows them to rule out certain physical causes for ED. They may also take blood tests.
The IIEF Questionnaire
Scientists Rosen and colleagues (1997) sought to find a reliable, self-administered measure of erectile function that is scientifically sound and useful for diagnosis. These researchers also wanted to create a tool for detecting treatment-related changes in patients with ED. They developed the IIEF, a test that analyzed five factors: erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction (Rosen et al, 1997). The International Index of Erectile Function (IIEF) addresses the relevant aspects of male sexual function and is psychometrically sound. Many doctors now use this questionnaire to evaluate for ED.
Dynamic Penile Color-Duplex Ultrasound
The majority of patients will rarely be diagnosed through dynamic penile color-duplex ultrasound (D-PCDU), but it is a valuable diagnostic tool. It involves an injection to the penis, before scanning the penis with an ultrasound scanner to evaluate various parameters such as resistance index, peak flow velocity, and degree or arterial dilation. The information from the scan helps with diagnosing vascular ED.
To evaluate the efficacy and clinical utility of D-PCDU, ED researchers Aversa & Sarteschi (2007) reviewed the extensive, evidence-based literature on the interpretation of D-PCDU criteria and usage. They found that one advantage to this ultrasound method was that it screened patients to identify a normal arterial response of the penile cavernous arteries. The scientists concluded that in the near future, D-PCDU may be used for diagnosis of ED in patients who present with or without vascular risk factors, especially those who do not respond to oral medications. Because men over the age of 55 years, as well as those with complex associated conditions, were likely to have multi-organ dysfunction, D-PCDU could help with accurate diagnosis. The researchers found that others who would benefit included patients with a history of pelvic trauma, those with penile shaft fractures, and men with Peyronie’s disease.
Nocturnal Penile Tumescence Study
A common diagnostic test for ED is nocturnal penile tumescence (NPT). NPT is the name for the spontaneous erections (around three to five a night) that occur during sleep or on waking up in men without ED. NPT can be measured by several methods, including strain gauges, stamp testing, and sleep lab evaluation.
Normal nocturnal penile tumescence and rigidity (NPTR) depends on the integrity of the coricospinal efferents (nerve pathways) to the penis, as well as the vascular responsiveness of the penile tissues to the nerve signals. Although helpful in diagnosing ED, it provides little information about the actual causes of the ED.
Penile Electromyogram
Many doctors find that electromyogram (EMG) testing is a good way to evaluate ED. Penile electromyogram studies evaluate the smooth muscle electrical activity of the penis, and are useful for patients with diabetes, spinal cord injuries, or for those who have undergone radical pelvic or prostate surgery (Broderick, 1998). Researchers Stief and associates (1997) investigated the use of penile EMGs in 31 men and concluded that computerized EMG evaluation was a feasible diagnostic tool.
Other Diagnostic Tests
Other diagnostic tests include selective internal pudendal pharmacoangiography, penile plethysmography, penile blood pressures, penile brachial index, dynamic infusion cavernosometry /cavernosography, and nuclear washout radiography. Because veno-occlusive dysfunction leads to poorly sustained erections, the dynamic infusion cavernosometry and cavernosography tests are often helpful in diagnosing ED. Doctors reserve these invasive tests for those considering vascular reconstructive surgery (Broderick, 1998).
References
- Aversa, A. & Sarteschi, L.M. (2007). The Role of Penile Color-Duplex Ultrasound for the Evaluation of Erectile Dysfunction. The Journal of Sexual Medicine, 4(5): 1437 – 1447. DOI: 10.1111/j.1743-6109.2007.00546
- Broderick, G.A. (1998). Evidence based assessment of erectile dysfunction. International Journal of Impotence Research, 10(Suppl. 2): S64 – S73.
- Cohan, P. & Korenman, S.G. (2001). Erectile dysfunction. The Journal of Clinical Endocrinology and Metabolism 86(6): 2391 – 2394. doi: 10.1210/jc.86.6.2391
- Rosen, R.C., Riley, A., Wagner, G., Osterioh, I.H., Kirkpatrick, J., & Mishra, A. (1997). The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology, 49(6): 822 – 830. DOI: 10.1016/S0090-4295(97)00238-0
- Stief, C.G., Kellner, B., Hartung, C. et al. (1997). Computer-assisted evaluation of the smooth-muscle electromyogram of the corpora cavernosa by fast Fourier transformation. European Urology, 31(3): 329 – 334.
Last reviewed 26/Feb/2014
