AB132. Nocturnal penile tumescence monitoring: what have we done and what should we do?

Objective: Erectile dysfunction (ED) is a complex disorder caused by multiple etiologies. It has been categorized into psychogenic, organic and mixed. Nocturnal penile tumescence (NPT) is critical to differentiate the organic or psychogenic and to evaluate penile erectile function. This report reviews all NPT measurements published, and presents the characteristics of each method.

Methods: We retrospectively reviewed all available literature focusing on NPT monitoring through a systematic PubMed search using the keywords “nocturnal penile tumescence” and “erectile dysfunction”. The advantages and limitations of each NPT monitoring method were analyzed.

Results: To date, mainly seven methods and their modifications have been reported for NPT measurement: sleep laboratory testing, the mercury strain gauge, the stamp test, the erectometer, the Snap gauge, the RigiScan and nocturnal electrobioimpedance volumetric assessment (NEVA). Compared to direct observation and measurement from sleep laboratory testing, the invention and development of NPT recorders have largely improved the convenience of use; however, a variety of limitations exist for each method.

Conclusions: Though NPT measurements have experienced a long period of evolution and have their particular strengths, none of these measurements are regarded as the “golden standard”. In this review, we described the various types of NPT measurements, the quantitative parameters that they use for evaluating erectile quality and ED treatment effects, their utility in the etiologic diagnosis and differential diagnosis of ED, and the disadvantages associated with each. The ideal NPT test: (I) accurate and comprehensive; II) simple, wearable, convenient and less sleep interference; (III) inexpensive is desperately needed in clinic.

Keywords: Nocturnal penile tumescence (NPT); erectile dysfunction (ED); psychogenic ED; RigiScan