Failure of genital response (erectile dysfunction)

• in men, primarily erectile dysfunction
• in women, primarily vaginal dryness

Biology

erection depends on:

• intact arterial supply
• intact venous valves
• vascular changes caused by parasympathetic nervous system
• psychic erections are mediated by thoracic sympathetic outflow
• reflex erections result from sacral parasympathetic outflow
• androgens also influence erection, particularly those during sleep, via the limbic system

Epidemiology

• prevalence of 4-9%
• makes up 50% of male cases presenting to sexual problems service
• incidence rises with age (1.3% at 35 years, to 55% at 75 years)

Aetiology

• organic in 50%

1. Local:

a) Peyronie’s disease – progressive fibrosis in the tunica albuginea, resulting in curvature of the penis upon erection
b) Congenital abnormalities, such as hypospadias, epispadias, absence of suspensory ligaments
c) Priapism – may result in impotence if not properly treated within 24 hours

2. Endocrine:

a) Diabetes – causes a combination of arteriopathy and neuropathy
i) 2/3 of diabetic males are impotent
b) Hypogonadism – nocturnal erections are androgen dependent
c) Hyperprolactinaemia secondary to hypothalamic/ pituitary disease, phenothiazines, sometimes in alcoholics
d) Endorphins – naltrexone can improve impotence

3. Neurological:

a) Peripheral or autonomic neuropathy, e.g. diabetes, alcoholism
b) Radical pelvic surgery causing autonomic disruption
c) Spinal cord lesion, e.g. transection, multiple sclerosis

4. Vascular:

a) arterial disease interfering with blood supply to pelvic organs
b) incompetent venous valves

5. Pharmacological:

a) alcohol
b) antihypertensives – ganglion blockers interfere with both sympathetic and parasympathetic systems and cause both impotence and ejaculatory failure

6. Psychological:

a) classical history of lack of sexual interest, but continued morning erections suggests psychological cause

7. Psychoanalytical:

a) anxiety about the persecutory object
b) unresolved Oedipal conflict
i) in younger men with primary impotence
c) deep ambivalence about the intimate object leading to fear of sexual failure
d) narcissistic crisis
i) in middle-aged men with secondary impotence

8. Cognitive:

a) due to negative self-image within a depressive view of the relationship, and is linked to abandonment fear
b) anxiety plays a key role
c) fear of hurting female/ fear of pregnancy/ distaste for female genitalia/ trying too hard