Abstract

Objective: Nocturnal penile tumescence (NPT) test is a time-consuming, cumbersome, and relatively expensive method which is used for the diagnosis of erectile dysfunction (ED). The aims of the study were to clarify the relationship between erotic and nocturnal erections and to evaluate the diagnostic efficacy of the audiovisual sexual stimulation (AVSS) test with and without medication. 

Materials and methods: A total of 30 patients with ED were examined. Each patient filled in an International Index of Erectile Function-5 (IIEF-5) questionnaire. AVSS and NPT tests were performed using the RigiScan Plus. AVSS test was performed with and without medication (sildenafil citrate 50 mg). Patients were divided into two groups (psychogenic and organic groups) according to NPT and AVSS test results. 

Results: The mean age of the patients was 46.4 (23-69) years and IIEF-5 score was 10.8±4.5. Positive AVSS test was found in 18 (85.7%) of the 21 patients with positive NPT test. Negative AVSS test was found in 7 (77, 8%) of the 9 patients with negative NPT test. The specificity of AVSS test was 85.7% and sensitivity was 77.8% for the psychogenic groups. The overall accuracy rate was 83.3%. 

Conclusion: The NPT test is more expensive, cumbersome, and discomfortable than the AVSS test. Although efficiency of both tests is similar, the AVSS test seems more advantageous. We suggest that the AVSS test without medication should be performed as the first step in the diagnosis of the patients with ED. In patients with negative test result, the AVSS test with medication should be performed as the second step diagnostic method.