Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases

Erectile Dysfunction

Erectile dysfunction, or impotence, refers to a male's inability to attain or maintain penile erection sufficient to complete intercourse. The patient with primary impotence has never achieved a sufficient erection. Secondary impotence is more common but no less disturbing than the primary form, and implies that the patient has succeeded in completing intercourse in the past.

Transient periods of impotence aren't considered dysfunction and probably occur in half of adult males. The prognosis for erectile dysfunction patients depends on the severity and duration of their impotence and the underlying causes.

Age Alert

Erectile dysfunction affects men of all age groups but increases in frequency with age.

Causes

Psychogenic

·   Personal sexual anxieties that generally involving guilt, fear, depression, or feelings of inadequacy resulting from previous traumatic sexual experience, rejection by parents or peers, exaggerated religious orthodoxy; abnormal mother-son intimacy, or homosexual experiences

·   Disturbed sexual relationship, possibly stemming from differences in sexual preferences between partners, lack of communication, insufficient knowledge of sexual function, or nonsexual personal conflicts

·   Situational impotence, a temporary condition in response to stress

Organic

·   Chronic diseases that cause neurologic and vascular impairment, such as cardiopulmonary disease, diabetes, multiple sclerosis, or renal failure

·   Liver cirrhosis causing increased circulating estrogen due to reduced hepatic inactivation

·   Spinal cord trauma

·   Complications of surgery, particularly radical prostatectomy

·   Drug- or alcohol-induced dysfunction

·   Genital anomalies or central nervous system defects

Pathophysiology

Upon stimulation, chemicals are released in the brain that cause signals to pass down the spinal cord and outward through special nerves into the penis. These nerves release another chemical (nitric oxide) that causes the smooth muscles of the penis to relax and blood to rush into the erectile bodies, causing erection. Neurologic dysfunction results in lack of the autonomic signal and, in combination with vascular disease, interferes with arteriolar dilation. The blood is shunted around the sacs of the corpus cavernosum into medium-sized veins, which prevents the sacs from filling completely. Also, perfusion of the corpus cavernosum is initially compromised because of partial obstruction of small arteries, leading to loss of erection before ejaculation.

Anxiety or fear can prevent the brain signals from reaching the level required to induce erection. Medical conditions can block the erection arteries or cause scarring of the spongy erection tissue and prevent proper blood flow or trapping of blood and, therefore, limit the erection.

Signs and symptoms

·   Inability to achieve or sustain a full erection

·   Anxiety

·   Perspiration

·   Palpitations

·   Loss of interest in sexual activity

·   Depression

Diagnostic test results

·   A detailed sexual history helps differentiate between organic and psychogenic factors and primary and secondary impotence.

·   Fulfilling the diagnostic criteria for the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition, Text Revision by meeting either of two criteria:

§  persistent or recurrent partial or complete failure to attain or maintain erection until completion of sexual activity

§  marked distress or interpersonal difficulty occurs as a result of erectile dysfunction.

Treatment

Psychogenic impotence

·   Sex therapy including both partners (course and content of therapy depend on the specific cause of dysfunction and nature of the partner relationship)

·   Teaching or helping the patient to improve verbal communication skills, eliminate unreasonable guilt, or reevaluate attitudes toward sex and sexual roles

Organic impotence

·   Reversing the cause if possible

·   Psychological counseling to help the couple deal realistically with their situation and explore alternatives for sexual expression if reversing the cause isn't possible

·   Sildenafil, tadalafil, or vardenafil to cause vasodilatation within the penis

·   Adrenergic antagonist, yohimbine, to enhance parasympathetic neurotransmission

·   Testosterone supplementation for hypogonadal men (not for men with prostate cancer)

·   Prostaglandin E injected directly into the corpus cavernosum (may induce an erection for 30 to 60 minutes in some men)

·   Surgically inserted inflatable or noninflatable penile implants

P.319

ERECTILE DYSFUNCTION

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