Sleep-Related Painful Erections: A Meta-Analysis on the Pathophysiology and Risks and Benefits of Medical Treatments

Background: Patients with sleep-related painful erections (SRPEs) have frequent awakenings from deep penile pain during nocturnal erections. This results in severe sleep deprivation. Aim: To review the current literature on SRPEs and discuss the pathophysiologic theories and risks and benefits of medical treatments. Methods: PubMed was searched using the terms sleep-related painful erections, nocturnal priapism, treatment, and sleep-related erections. Outcome: Variables included patient demographics, medical history, diagnostics, hypotheses on pathophysiology, and treatment modalities and their effect on SRPE in the short and long term. Results: The search yielded in 66 SRPE cases that were analyzed, including our mono-institutional series of 24 patients. The phenomenon of SRPEs is not well understood. Theories about pathophysiology concerned increased serum testosterone levels, altered autonomic function, compression of the lateral preoptic area, coexistent obstructive sleep apnea syndrome, the existence of a "compartment syndrome," and psychosomatic factors. Except for polysomnographic findings that showed sleep fragmentation and decreased sleep efficiency in all patients, other diagnostic results varied widely. Multiple agents were tried. Baclofen and, to lesser degree, clonazepam showed noticeable results, most likely due to their influence on the g-aminobutyric acid system and, hence, suppression of glutamate release. In addition, baclofen relaxes the ischiocavernosus and bulbospongiosus muscles, which are involved in penile erection. Clinical Implications: By providing a critical analysis and complete overview on the limited literature about this overlooked and undermanaged condition, this review contributes to a better understanding of the pathophysiology and provides directions for future research on the treatment of SRPE. Strengths and Limitations: Because the literature on SRPEs includes only case reports and small case series, the level of evidence of treatment advice is limited. Conclusion: The pathophysiology of SRPEs is not yet clarified. Further diagnostic evaluation, including electromyography of the ischiocavernosus and bulbospongiosus muscles to elucidate the pathophysiology, is recommended. Prospective controlled investigations are warranted to assess the efficacy and safety of long-term use of baclofen and develop evidence-based treatment advice. Copyright (C) 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.