Nocturnal penile tumescence (NPT) and rigidity monitoring in neurogenic impotence: Interpretations and limitations

This paper describes the current state of nocturnal penile tumescence (NPT) testing for men with neurogenic impotence. The paper describes the development of the procedure and offers suggestions regarding interpretations of NPT and rigidity findings. In addition, the paper discusses techniques for assessing the neurogenic causes of impotence as well as other polysomnographic findings. Specific attention is given to somatic nerve function tests, autonomic erectile dysfunction and the investigation of cerebral autonomic and somatic projections. The paper concludes by discussing new avenues of study.