impotence In sexual problem clinics, men tend to present with problems about actually ‘doing it’ rather than failing to enjoy it. Impotence in the male is not simply the inability to achieve and retain
erection of the penis (erectile dysfunction): under this heading are commonly subsumed premature
ejaculation (precipitate emission of semen before the sexual act is fully completed), and retarded ejaculation, in which the man is either unable to achieve
orgasm and ejaculation, or else finds that this takes an exceedingly long time. The same individual may well experience different forms of sexual dysfunction at different times and on different occasions.
Erections of the penis occur for sexual purposes and also during the night during REM (rapid eye movement) sleep. Impotence is usually understood to mean a lack of sufficient firmness and stiffness of the penis at the time of sexual intercourse. For a normal sexual erection the following events must occur: (i) There needs to be sufficient sexual stimulus. This can be sexy mind pictures, seeing one's partner naked, the smell of one's partner or the touch of one's partner, and these stimuli are particularly intense with a new partner. Impotence often occurs at a time of life when these various stimuli are less attractive than before.(ii) As the penis starts to become erect there is a relaxation of muscle fibres in the walls of the penile arteries, and as a result there is increased blood flow into the penis. In older men with high blood pressure and hardening of the arteries this increased blood flow occurs less readily.(iii) At the same time as more blood enters the penis there is relaxation of muscle fibres inside the twin erectile bodies (corpora cavernosa) in response to nitric oxide released from nerve endings within them. As a result of the increased blood flow and relaxation of corpora cavernosal muscle there is an increased pressure within the erectile bodies, and this shuts off exit veins from the penis, thus the erect penis is firm and warm. We now know that the health of the erectile muscle is maintained by periodic perfusion with warm arterial blood. When the penis is soft and cold and containing only a little venous blood the oxygen tension within the corpora cavernosa is very low. If periodic erections do not occur there is progressive damage to the erectile muscle which is gradually replaced by fibrous tissue and becomes less responsive to nitric oxide. Thus, there is truth in the saying ‘Use it or lose it’.
There are a number of physical causes for erectile failure. Damage to the local peripheral nerves or blood vessels, injury or disease of the spinal cord, ageing, conditions causing narrowing or obstruction of the blood vessels, neurological disorders, hormonal deficiencies, diabetes, and some drugs can all have this effect. Local conditions leading to impotence include
priapism — a persistent and painful erection, which may result for reasons not fully understood in permanent erectile failure — and Peyronie's disease, which causes the penis to bend to one side during erection. However, although it is now recognized that physical factors may contribute to a far greater number of cases of impotence than previously supposed, in many cases the aetiology is psychological. Like other apparently reflex physical actions, erection can be affected by the state of mind of the individual. Given that sexual interaction is an emotionally-laden area of life, impotence may occur especially in situations which are felt to be particularly stressful and in which there is considerable pressure on the male to ‘perform’, for example on the first occasion with a new partner. A considerable percentage of men experience intermittent and situational impotence.
Failure of sexual power is still regarded as a slur on the manhood of an individual and is very seldom admitted to, in spite of being perhaps one of the most common of sexual difficulties. So sensitive a subject is it that men tend not to take the problem to their general practitioners but seek out various forms of private assistance. The aid to failing manhood once offered by dubious quacks in newspaper small advertisements is now offered by ‘Well Man’ clinics and similar institutions via explicit advertisements in the quality papers covering several column inches, and indeed on World Wide Web pages.
There are a number of procedures which the physician can deploy to assess erectile function and to determine whether the failure is psychological in origin or whether there is some organic cause. Simple measures are ascertaining whether erections take place during sleep (using a mercury-in-rubber strain gauge) or in response to erotic materials, though the first is not always practicable and the second may not be personally or culturally acceptable. If erection occurs, this does not totally exclude physical causes, but strongly suggests psychological causation. Other means of investigation are seldom as non-invasive. Moreover, investigations into penile blood flow during erection and other vascular phenomena, and on the nerve system of the penis, show rather contradictory results, which limit their usefulness as tests.
Injections into the corpora cavernosa may be used as a diagnostic procedure to assess erectile response, and have been enthusiastically taken up by some practitioners as a treatment. This appears to be effective in cases where there is a neurological reason for erectile failure, and some cases of psychological origin also respond to this treatment, but there are problems in cases with severe damage to the blood supply.
For psychogenic impotence, or when there are contributing psychological factors, the central problem is usually to overcome the negative pattern established by performance anxiety. Use of ‘sensate focus’ techniques may be advised, encouraging the man to engage in various forms of pleasurable touching and stimulation without obligation to attain an erection and attempt penetrative intercourse. For premature ejaculation, the use of ‘stop-start’ (reaching a state of high arousal, ceasing stimulation, and then resuming) and ‘squeeze’ techniques (firmly squeezing the tip of the penis to prevent ejaculation), though requiring much repetition in order to break the old habit and establish the new, has been shown to be of some benefit. Sometimes the impotence is due to deeper and more longstanding problems for which psychotherapy may be advised.
Recently, various medicines have been found to exaggerate the nitric oxide stimulus that relaxes the corpora cavernosal muscle. The medicine in most general use in the UK in the 1990s was self-injection of
prostaglandin or alternatively a urethral prostaglandin pellet. However, oral tablets containing a phospho-diesterase inhibitor, sildenifil, (trade name
Viagra) are nearly as effective and have become the first line treatment throughout the world. An interesting side-effect, experienced by 5–10% of men is an alteration in the perception of light and this is explained by sildenifil inhibiting also phosphdiesterase-6, which is found in cells in the retina of the eye. When men experience this side effect, light may appear brighter or objects may appear with a blueish tinge. In general, however, sildenifil has been shown to be very safe and although there has been a scare about heart attacks the numbers reported are no different from the numbers that would have been expected in a population of similar age who have not taken the drug. Another new tablet that is now available contains apomorphine, and in contrast to sildenifil works by influencing chemical pathways in the hypothalamus in the brain, again, like sildenifil, only in the context of sexual stimulation. There are several sildenifil-like and other tablets being developed and these and other so-called Quality-of-life drugs are causing major funding problems for health care systems.
If all else fails, there is the possibility of implanting a penile prosthesis — a simple plastic splint, or an inflatable implant, — but there is rarely a good case for this, certainly in no more than 1% of patients, and most of them would be paraplegic.
The problem of impotence is best — and most often — addressed in a multidisciplinary clinic, including psycho–sexual counsellors, psychologists, endocrinologists, and urogenital surgeons.
Impotence is often considered to be one of the prices paid for leading a modern, urbanized, and ‘unnatural’ life, and to bear some causal relation to the changing social role of women. Anxiety about the ability to manifest manhood by sustaining an erection, however, appears to have been prevalent throughout history, during which few women enjoyed anything like the social and economic power now delineated as so threatening. Accusations of manhood stolen by witchcraft and charms for its restoration suggest that in apparently ‘simpler’ societies erection was not necessarily a reliable biological reflex, and that impotence should, perhaps, be seen as one of the prices humanity has paid for becoming self-conscious — indeed, human.
Lesley A. Hall, and Tim Hargreave
See
urogenital system.See also
coitus;
ejaculation;
penis.
