Sleep investigations in erectile dysfunction.

Regarding the aetiology of erectile dysfunction, beside numerous organic causes in many cases psychological factors play an important role. The pathophysiological mechanisms underlying the so-called psychogenic erectile dysfunction are not yet understood. Based on a neurobiological approach to psychogenic erectile dysfunction, polysomnographic investigations were carried out with the aim of identifying possible alterations of the sleep EEG. 24 male patients with psychogenic erectile dysfunction without detectable organic factors or other mental disorders were studied in the sleep laboratory, as well as an age-matched control group without sexual dysfunctions. Beside a reduction of sleep efficacy, the most prominent finding was a shortening of REM latency in the patients compared to the controls. Moreover, spectral analysis revealed a reduced theta power for all sleep stages and a reduced delta power for stage II and slow wave sleep in the patients. The findings support the point of view that psychogenic erectile dysfunction is an organic disorder of the brain. The sleep EEG abnormalities may reflect dysregulations in limbic structures which are suggested to be involved in the pathophysiology of sexual dysfunctions. As these alterations had also been reported for other mental disorders, particularly depression, they appear to be non-specific biological abnormalities for different psychiatric syndromes, including psychogenic erectile dysfunction.

Temporal relationship between nocturnal erections and rapid eye movement episodes in healthy men.

The exact temporal relationship between spontaneous nocturnal erections and rapid eye movement (REM) sleep was studied in healthy men with the aim of creating a basis for a more sophisticated analysis of nocturnal erection measurements in physiological research and clinical applications. The vast majority of erectile events was coupled to REM episodes, where the latency between the beginning of erections and REM episodes showed a large variability. Moreover, a correlation analysis revealed a highly significant decrease of the latency over the course of the night. The time variant properties of the coupling between erections and REM sleep point to more complex dynamics of the central control of erections with regard to sleep regulation, indicating that REM sleep and REM-related erections are not completely interdependent. Beside the possibility of obtaining further insight into the physiological mechanisms underlying erectile function, the consideration of dynamic aspects in the assessment of nocturnal erection measurements might have potential clinical implications regarding both the diagnosis and the evaluation of therapies for erectile dysfunction.