- Clinical science
Erectile dysfunction is the most common presentation of sexual dysfunction in males and is characterized by an inability to maintain an adequate erection for sexual intercourse that lasts at least 6 months. The causes may be psychological, vascular, neurological, or hormonal. Diagnosis is made based on a detailed medical history and physical exam, relevant blood tests (e.g., testosterone, sexual hormone-binding globulin), and objective measurement of the remaining erectile function (nocturnal penile tumescence testing). Treatment includes counseling and, in cases with an organic cause, potentially mechanical vacuum pump therapy, medical therapy with phosphodiesterase-5 inhibitors, or surgery (penile prosthesis implant).
Premature ejaculation is characterized by an inability to delay ejaculation during vaginal penetration and is often accompanied by significant psychological distress. Proposed etiologies include penile hypersensitivity and psychological disorders such as depression and anxiety. The diagnosis is made with a medical history of short intravaginal ejaculation latency time, inability to delay or control ejaculation, and psychological strain. Treatment consists of SSRIs and local topical anesthetics with sex therapy and other psychotherapy as needed.
- Largely precipitated by the cerebral cortex
- Occurs in the following stages: genital stimulation → pudendal nerve afferents → sacral erection center S2–S4 (parasympathetic nervous system) → inferior hypogastric plexus; → efferent signal from the plexus leads to an erection; → relaxation of the cavernous smooth muscle → vasodilation (mediated by nitric oxide) → increased inflow of blood → erection (mainly caused by the corpora cavernosa)
- Cortical stimulation via visual, aural, and sensory stimuli or fantasy → impact on the thoracolumbar erection center T11–L2 (sympathetic nervous system) → inferior mesenteric plexus and superior hypogastric plexus; → acts synergistically with sacral parasympathetic signals to increase blood flow to corpora cavernosa → erection
- Sympathetic innervation to smooth muscle of vas deferens, seminal vesicle, and internal sphincter of bladder
- Erectile dysfunction: (= ): inability to achieve or sustain an erection sufficient in rigidity or duration for sexual intercourse
- See also
- Most common sexual disorder in men
Organic (most common)
- Vascular: hypertension, diabetes mellitus, cardiovascular disease, hyperlipidemia, smoking
- Neurogenic: stroke, brain or spinal cord injury, dementia, Parkinson disease, multiple sclerosis
- Endocrine: hypogonadism, hyperprolactinemia, thyroid disorders
- Antihypertensives (beta-blockers, thiazide diuretics)
- Antidepressants (SSRIs)
- Dopamine antagonists (e.g., antipsychotics); : increased prolactin secretion (anterior pituitary) → decreased GnRH secretion (hypothalamus) → decreased LH secretion (anterior pituitary) → decreased testosterone production (Leydig cells) →
- Iatrogenic: : surgery or radiotherapy (radical prostatectomy; , pelvic radiation)
- Trauma: pelvic fracture and urethral injury
- Alcohol abuse
- Psychogenic: depression, anxiety (performance-related), trauma from prior experiences, relationship issues, stress
- Mixed organic and psychogenic
- Largely a clinical diagnosis
- Detailed patient history and clinical exam
|Diagnostic criteria (according to DSM V)|
- Further tests to exclude organic disorders:
- Endocrinological laboratory analysis; : ↓ testosterone; , ↑ SHBG , ↑ prolactin; , ↓ LH; , ↓ FSH; , ↑ TSH, ↑ fasting glucose or hemoglobin A1C; , abnormal lipid profile
Nocturnal penile tumescence measurement (phallography): measurement of spontaneous nightly erections in erectile dysfunction (primarily performed in a sleep laboratory) to differentiate between organic from psychogenic erectile dysfunction.
- Lack of nocturnal erections suggests an organic etiology (neurogenic or vascular)
- Normal testing suggests a psychogenic etiology
- Duplex Doppler ultrasound or arteriography to identify suspected arterial inflow or venous leaks after injection of vasodilatory agent
- Important to identify the underlying etiology to manage lifestyle risk factors and initiate appropriate therapy
- Sensate focus exercises for performance anxiety
- Group psychotherapy
- Phosphodiesterase-5 inhibitors are considered the only first-line therapy: tadalafil, sildenafil, vardenafil.
- Testosterone replacement if patient's serum testosterone is low (e.g., in hypogonadism)
- Intracavernous injection therapy with papaverine: or prostaglandin E1 (alprostadil) are second-line therapies if PDE-5 inhibitors are ineffective.
Etiology: largely unknown, but the following factors have been proposed:
- Psychogenic factors: depression/anxiety, relationship problems, irregular sexual intercourse
- Organic factors: penile hypersensitivity, hyperexcitability of the reflex arc
|Diagnostic criteria (according to DSM V)|
- The indication primarily depends on the psychological strain on the affected individual.
- Psychotherapy/behavioral therapy
- Medical therapy
- Epidemiology: Incidence increases with age ≥ 50 years.
- Etiology: psychological stress (e.g., childhood abuse, sexual trauma)
|Diagnostic criteria of delayed ejaculation (DSM V)|
- Treatment: ; other types of therapy depending on the underlying cause of psychological stress