What constitutes an abnormal erection history and how does it differ from nocturnal penile tumescence (NPT)?

From the Guidelines

Abnormal erection history is characterized by a persistent penile erection that continues hours beyond, or is unrelated to, sexual stimulation, with a duration of greater than 4 hours, as defined by the American Urological Association guideline on the management of priapism 1. This condition differs significantly from nocturnal tumescence, which refers to normal erections that occur during sleep, particularly during REM sleep phases. While a man with erectile dysfunction may struggle during sexual encounters, he may still experience normal nocturnal erections. This distinction is clinically important because preserved nocturnal erections in a patient with daytime erectile difficulties often suggests a psychological rather than physiological cause. Physicians evaluate this through medical history, physical examination, and sometimes specialized testing like nocturnal penile tumescence monitoring (NPT), which measures nighttime erections using strain gauges. The presence of normal nocturnal erections (typically 3-5 per night, lasting 25-35 minutes) in a man reporting erectile dysfunction during sexual activity helps clinicians differentiate between organic causes (vascular, neurological, hormonal) and psychological factors (anxiety, depression, relationship issues). According to the most recent guideline on the diagnosis and management of recurrent ischemic priapism, priapism in sickle cell patients, and non-ischemic priapism, published in 2022, the management of abnormal erection history requires prompt evaluation and may require emergency management, with intracavernosal phenylephrine being a recommended initial treatment option for prolonged erections of four hours or less following intracavernosal injection pharmacotherapy for erectile dysfunction 1. This guideline also emphasizes the importance of differentiating between ischemic and non-ischemic priapism, as well as the need for clinician judgment in managing patients with recurrent ischemic priapism. Key points to consider in the management of abnormal erection history include:

• Differentiating between ischemic and non-ischemic priapism
• Evaluating the patient's medical history and performing a physical examination
• Using specialized testing like NPT to measure nighttime erections
• Considering intracavernosal phenylephrine as an initial treatment option for prolonged erections
• Providing patient education on the management of abnormal erection history and the importance of seeking medical attention if symptoms persist or worsen. It is essential to prioritize the patient's morbidity, mortality, and quality of life when managing abnormal erection history, and to consider the most recent and highest-quality evidence when making treatment decisions, such as the 2022 guideline on the diagnosis and management of recurrent ischemic priapism, priapism in sickle cell patients, and non-ischemic priapism 1.

From the Research

Abnormal Erection History

• Abnormal erection history can be characterized by the inability to achieve or maintain an erection sufficient for satisfactory sexual performance, also known as erectile dysfunction (ED) 2, 3, 4.
• ED can be caused by various factors, including vascular, neurologic, psychological, and hormonal factors, as well as certain medical conditions such as diabetes mellitus, hypertension, and prostate cancer treatment 2, 3.
• The diagnosis of ED involves a full medical and sexual history, a focused clinical examination, and laboratory tests such as fasting glucose levels and lipid profiles 3.

Nocturnal Tumescence

• Nocturnal tumescence refers to the spontaneous erections that occur during sleep, typically during the rapid eye movement (REM) stage 5, 6.
• These erections are a normal part of male physiology and are thought to be related to the release of nitric oxide and other neurotransmitters during sleep 5.
• Nocturnal tumescence can be affected by various factors, including age, sleep quality, and certain medical conditions such as erectile dysfunction 5, 6.
• Sildenafil, a phosphodiesterase type 5 inhibitor, has been shown to improve nocturnal penile tumescence and rigidity in normal men and in men with psychogenic erectile dysfunction 5, 6.

Difference between Abnormal Erection History and Nocturnal Tumescence

• Abnormal erection history refers to the inability to achieve or maintain an erection sufficient for satisfactory sexual performance, whereas nocturnal tumescence refers to the spontaneous erections that occur during sleep 2, 5.
• While ED can affect nocturnal tumescence, the two conditions are distinct and require different diagnostic and treatment approaches 3, 6.
• The evaluation of men with ED requires a comprehensive medical and sexual history, a focused clinical examination, and laboratory tests, whereas the evaluation of nocturnal tumescence typically involves the use of devices such as the RigiScan Plus to monitor erections during sleep 3, 6.