ED is when a man cannot develop or maintain an erection during sexual intercourse. This is also referred to as ‘impotence’. Other symptoms of ED include reduced libido or sexual desire. If this condition persists for more than a few weeks or months, your doctor is likely to diagnose it as ED.
An erection basically occurs when there is a hydraulic effect when blood enters, and is retained in sponge like bodies within the penis, resulting from a sexual arousal that transmits signals from the brain to nerves in the penis.
There are two mechanisms that manage a penile erection – the reflex erection, which is achieved by direct contact with the penile shaft; and the psychogenic erection which results from emotional or erotic stimuli. Reflex erection uses the lower portion of the spinal cord and the peripheral nerves. While psychogenic erection uses the limbic system of the brain. But both mechanisms require an intact neural system for a total and successful erection. When the nervous system stimulates the penile shaft, it secretes nitric oxide which relaxes the smooth muscles of the main erectile tissue of the penis (corpora cavernosa) and leads to an erection.
There are two other factors that are very important to develop a healthy penile system – an intact pituitary gland and sufficient levels of testosterone, which is produced by the testes.
Among the more important organic causes for impotence are diabetes, cardiovascular disease, neurological problems, side effects of drugs and hormonal deficiencies. Impotence has also been known to be caused by arsenic contamination of drinking water, potassium deficiency and psychological issues.
There are so many reasons for experiencing erectile dysfunction, or impotence. While some are a result of mental issues, others are medical problems. Quite often, ED itself causes psychological problems as it can affect a man’s image and self-esteem, as well as his relationships. It’s a bit of a vicious cycle, as psychological impotence occurs when erection fails due to one’s negative state of mind rather than a physical drawback. Cause and effect here are highly debatable.
There are many reasons for the occurrence of ED. At a general level it can be attributed to:
- Performance anxiety
- Excessive alcohol consumption
- Relationship problems
However, there are many medical conditions that can cause ED, coupled with the medications prescribed for these conditions. The causes of ED include:
- Heart disease
- Kidney failure
- Cavernosal disorders (Peyronie’s disease)
- Use of tobacco/drugs – nicotine and anti-depressants. Smoking may lead to arterial narrowing
- Multiple Sclerosis
- Enlargement of the prostate gland
- Parkinson’s disease
- Neurogenic disorders
- Psychological causes
- Hormonal deficiency
- Disorders of the neural system
- Spinal cord injuries
- Insufficient penile blood supply
- Aging – men over 60 are four times more likely to suffer from ED than men over 40
- Bicycling – both vascular and neurological problems can be caused by compression
- Regular alcohol use
It has been noted that men who consumed alcohol regularly suffered from ED. Seventy two per cent of men who were dependent on alcohol, were diagnosed with sexual dysfunction which also includes premature ejaculation.
There is no specific formal test for the diagnosis of erectile dysfunction, hence a thorough physical examination is required. Conditions such as obesity, poor dietary habits, poor physical health, and cardiovascular diseases such as peripheral vascular disease and coronary artery disease need to be eliminated as the causes of ED. An undetected groin hernia may also cause sexual dysfunction, however, it is easily curable.
One of the yardsticks to differentiate between physiological and psychological impotence is to identify if a patient has ever had an erection. If the answer is never, then it is likely to be physiological. If the answer is sometimes, then it may well be either physiological or psychological.
Among some of the testing methods used to determine the occurrence of ED, are:
- Penile nerves function
The presence of sufficient nerve sensation in the penis is determined by tests such as the bulbocavernosus reflex test.
- Penile biothesiometry
Nerve function and sensitivity in the shaft and glans of the penis are evaluated using electromagnetic vibrations.
- Duplex Ultrasound
Prostaglandin is a hormone-like stimulator that the body produces. It is injected to induce an erection. An ultrasound is then carried out to evaluate venous leak, blood flow, atherosclerosis, and calcification or scarring of the erectile tissue. Vascular dilation is observed and penile blood pressure is measured.
- Nocturnal penile tumescence (NPT)
Changes in penile rigidity during nocturnal erection are measured by one of two methods: strain gauge and snap gauge. The absence of nocturnal erections may be due to a problem with nerve function or blood supply in the penis.
- Dynamic infusion cavernosometry (DICC)
This measures vascular pressure in the corpus cavernosum during an erection by pumping a fluid into the penis at a specific rate and pressure.
- Magnetic resonance angiography (MRA)
Similar to an MRI, this uses radio waves and magnetic fields for detailed images of the blood vessels. A contrast agent may be injected into the blood steam that makes vascular tissues stand out against other tissues. Hence, enhanced data about the blood supply and other vascular anomalies is provided.
- Corpus cavernosometry
Cavernosography, the process of measuring the vascular pressure in the corpus cavernosum. Saline is infused into the corpus cavernosum under pressure, using a butterfly needle. Then the flow rate that is needed to maintain an erection is studied to identify the degree of venous leakage.
Treatment for ED varies according to the causes. For instance, psychological impotence requires therapy and can also respond to placebo treatment. While first line treatment usually involves a trial of PDE5 inhibitor drugs – earlier versions were sildenafil or Viagra. Treatment can also include prostaglandin tablets in the urethra, a penile prosthesis, injecting into the penis, a penis pump or vascular reconstructive surgery.
Research continues about the efficacy of exercise to treat ED, but it is considered a preventive if taken up during mid-life. Significant improvements have been noted when tobacco smokers gave up nicotine.
The following modes of treatment are used most commonly:
- Oral medication
Phosphodiesterase type 5 inhibitors
A group of enzymes known as the cyclic nucleotide phosphodiesterases help destroy the cyclic nucleotides cyclic adenosine monophosphate (cAMP) and cyclic guanosinemonophosphate (cGMP). Phosphodiesterases are available in different molecular forms and are not evenly distributed through the body. One form of phosphodiesterase is known as PDE5, and when PDE5 is inhibited, there is an increase in the amount of cGMP that is provided in the blood supply to the penis, thereby increasing the flow of blood. The PDE5 inhibitors sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) are prescription drugs and are consumed orally.
- Injected medication
Injection therapy is another mode of treatment, which involves the injecting of drugs into the penis, such as phentolamine, prostaglandin E1 or papaverine.
- Topical medication
A combination of alprostadil and DDAIP (a permeation enhancer) are used in the form of a topical cream as a first line treatment for ED. The brand name is Vitaros and it has been approved for use in Canada.
The FDA has approved several vacuum therapy devices to be sold only with a doctor’s prescription. The device applies negative pressure to help pull blood into the penis. Known as a penis pump, it can be used just before sexual intercourse takes place. It is basically an external vacuum pump that can help attain erection with a separate compression ring fitted to the penis to maintain the erection.
- Extracorporeal shockwave therapy
This is a non-surgical, non-drug fairly recent treatment for ED that has no side-effects. It is the same as the therapy used in cardiology, urology and orthopedics, and when used at higher energies for lithotripsy to break up kidney stones. Although it has still not been approved by the FDA, it has been approved for ED treatment for use in Canada, Europe, South America and some countries in the Middle East.
A German study of 224 groin hernia patients reported 23.2% of patients had preoperative sexual dysfunction. The sexual function of these patients improved after the surgery.
When all other options have failed, prosthetic implants have helped in which artificial rods have been inserted into the penis.