Summary

Background:

Erectile dysfunction (ED), a common problem in males of all ages, can be of organic, psychogenic or combined etiology. Organic ED is mainly caused by vascular and neurological disorders. One of the available tests for differentiating organic from inorganic ED is measuring penile tumescence and rigidity during the REM phase of sleep. However, this test lacks the ability to differentiate between a vascular and non-vascular cause of organic ED. 

Objectives:

To compare the results of the EndoPAT test and the nocturnal penile tumescence (NPT) test in patients with erectile dysfunction.

Methods:

Twenty patients with ED were recruited for the study. Each participant was evaluated by the SHIM score, RigiScan during polysomnography, and two EndoPAT tests (at the beginning and end of the study).

Results:

Seventeen patients had SHIM score ≤ 21; 4 of them had organic ED with a mean EndoPAT score of 1.49, significantly lower than the 1.93 mean EndoPAT score of the 11 patients in the psychogenic ED group (P = 0.047). Two participants had a neurological impairment (spinal trauma and herniated disk). The average SHIM score in the vascular organic group was 6.25 points as compared to 11.69 for the psychogenic group (P = 0.027). The positive predictive value was 43% and the negative predictive value 90%.

Conclusions:

EndoPAT could be helpful in excluding organic ED.