Sexual dysfunction after spinal cord injury often occurs, probably because of the national character, most patients will not seek medical attention for this, but it is indeed an important disease, which has a great impact on the patient’s body and mind.
1, the relationship between the plane of injury and the severity of sexual dysfunction
T10 ~ L2 plane above the complete spinal cord injury so that all male and female genital sensation loss. But direct stimulation can make the penis reflexive erection or labia reflexive engorgement, vaginal lubrication, clitoral swelling, the reason for this phenomenon is the presence of sympathetic and parasympathetic reflexes below the plane of injury.
In complete injuries in the S2 to 4 planes, there is a complete loss of genital sensation, the male loses the ability to have an erection and ejaculate, and it is impossible to have orgasm through genital stimulation.
Those with complete injury in the L2 to S1 plane show dissociative responses, meaning that men can have genital touch and psychogenic erection, but they cannot coordinate them. Both men and women are unable to have orgasm by genital stimulation.
Complete injury in the T10 to T12 planes can result in loss of sympathetic nerve activity and therefore loss of the psychogenic male penile erectile response and the female vaginal vascular engorgement response. If the sacral segment of the spinal cord below the plane of injury is unaffected, direct stimulation of the genitalia can produce reflex phenomena.
After a complete injury below the T12 level, psychogenic penile erection can still exist, but the duration of this erection is short and usually not sufficient for sexual intercourse. Psychological stimulation of women below the T12 plane can also cause clitoral engorgement, labial engorgement and vaginal lubrication, and can cause weaker than normal pleasure in the pelvic region. This pelvic reflex disappears in sacral or cauda equina injuries of the spinal cord. The function of motor, sensory and autonomic nerves retained after incomplete spinal cord injury varies, and the prediction of sexual function is less accurate.
2, male sexual dysfunction
①Erection: erection is a vascular phenomenon. The expansion and filling of blood vessels cause erection, and the penis weakens when the blood vessels close. Erection includes reflex erection and psychological (mental) erection. Psychological stimulation can cause both arousal and inhibition. Reflex erections due to touch can be inhibited due to psychological factors. The supraspinal excitatory and inhibitory mechanisms of erection are complex. The limbic system of the brain and the hypothalamus play a key role. Visceral efferent nerve fibers emanate from the brain via the lateral vertebral tracts of the spinal cord and travel down the spinal cord. The erectile center of the spinal cord is associated with the sympathetic preganglionic fibers from T11 to L2 and the parasympathetic nerves from S2 to S4. The parasympathetic nerves work in concert with the sympathetic nerves to produce erections. Nitric oxide is the erectile neurotransmitter. Patients with complete inferior neuronal paraplegia lose the ability to have a reflex erection, but can have a psychogenic erection suggesting a link between sympathetic efference and erection. The reflex sacral segment is parasympathetically mediated and triggered by sensory afferents from the pubic nerve.T10 is the key plane for the presence or absence of genital pain in paraplegic patients.
Overall, 74% to 99% of patients can have an erection and 7% to 8% can ejaculate. The majority of patients with cervical and thoracic marrow injuries can have an erection. Of the patients with the ability to have an erection, 76% recovered within 6 months of the injury and the rest within 1 year. Of these, 23% could have successful intercourse and 10% could ejaculate. 5% were fertile. Ninety-three percent of those with complete upper motor neuron damage and 98% of those with incomplete damage had reflex erection (30% had the ability to ejaculate). The ability to have a psychological erection was found in 26% of patients with complete lower motor neuron damage and 83% of those with incomplete damage had the ability to have a psychological erection.
②Ejaculation: Ejaculation is primarily controlled by sympathetic nerves, including bladder neck closure, somatic reflexes and synergistic contractions of the cavernous muscles, seminal vesicles and vas deferens. Only 4% of those with complete upper motor neuron damage have the ability to ejaculate, and 30% of those with incomplete damage. Complete damage to lower motor neurons was found in 18% and incomplete in up to 70% of cases.
Those with T12 to S2 planes can have mixed erections or ejaculation.
T4-5 plane damage can induce vegetative overreflexes during sexual impulses, and the mechanism is unknown.
③ Intercourse: 80% of those with incomplete lower motor neuron damage who have penile erection can have intercourse, of which 70% can ejaculate, but only 15-25% are satisfied.
④Testicular and hormonal function: the ability of the testes to produce sperm is reduced after injury. Adults can develop sclerosis of the interstitial tissue of the testes, atrophy of the interstitial cells and tubules, and adolescents can develop testicular dysgenesis. About 50% of patients can maintain normal sperm production capacity. Because patients with spinal cord injury often adopt a sitting position (wheelchair), the relatively elevated temperature of the testes may be associated with the above abnormalities in testicular tissue. There is no information to confirm that these abnormalities are intrinsically linked to the level and extent of injury. Neither testosterone levels nor hypothalamic-pituitary-testicular axis hormone levels are significantly impaired, although there may be a decrease in plasma testosterone levels during the acute phase.
3. Techniques to restore erectile capacity
(1) Vasoactive substance penile cavernosal injection: Virag et al. (1982) first reported the use of poppyine injection into the penile cavernosum to restore erectile capacity in patients with spinal cord injury. brindley (1986) reported that seven smooth muscle relaxants could induce some degree of erection, including phentolamine, phenoxybenzamine ( phenoxybenzamine), Verapamil, and thymoxamine. The combination of opiates and phentolamine is most commonly used. The dose is usually 0.1 to 1.0 ml of a mixture of 25 mg/ml of poppyine and 0.83 mg/ml of phentolamine injected into the posterior aspect of the root of the penis, while some people prefer to use only poppyine. The dose used can be up to 10-80mg of poppyine and 2-10mg of phentolamine. the amount of injectable solution can be up to 2ml/time. The dose should be gradually increased from small until a satisfactory effect is achieved. An erection should appear within 3 to 5 minutes of injection and can be maintained for more than 60 minutes. Some advocate the use of a rubber band placed at the root of the penis after injection to block blood return and maintain an erection. In recent years, good results have been reported using prostaglandin injections alone or in combination with poppy bases.
The side effects of drug injections are mild and include: transient pain and loss of sensation at the injection site, bruising, and fibrosis at the injection site. The most serious comorbidity is abnormal penile erection, which is common in patients who are given a combination of poppy bases and phentolamine. Treatment is primarily withdrawal and penile decompression. Adrenergic drugs may also be considered, and surgical decompression may be used in special cases.
②Vacuum technique: Vacuum augmentation and contraction therapy uses a device that generates negative pressure in which the penis is placed, using negative pressure to augment the penis, and then using a contraction band placed at the root of the penis to block blood flow and keep the penis erect for about 30 minutes. Drug injections can be combined with the vacuum technique to enhance the therapeutic effect.
(3) Penile prosthesis: Penile prosthesis includes two categories: semi-rigid and filled. They have been more commonly used since the late 1970s. Semi-rigid prostheses include suspended, moldable and articulated types. Most silicone is used to increase the length, diameter and stiffness of the penis. Depending on the design, the direction of the penis can be changed by means of articulation, and there are also advocates for no adjustment. Filled prostheses include multi-component or implants. These prostheses tend to use a pump mechanism, i.e., a “reservoir” plus a pair of penile prostheses. These prostheses are much more expensive than semi-rigid prostheses. The “reservoir” can be implanted inside the body, which is known as the concealed type. The result is better than semi-rigid.
Most male patients with penile prostheses can achieve a largely satisfactory sexual life for their partners. It is also easier for patients to perform intermittent catheterization themselves. The main side effects are penile erosion, infection and mechanical failure of the prosthesis, with an overall incidence of 10-25%. When considering the use of a penile prosthesis it is necessary to fully consider the patient’s psychotherapy and fully understand the advantages and disadvantages of the chosen prosthesis as well as possible comorbidities.
④Other methods: The presacral nerve stimulator can be used as a treatment for urinary incontinence and can also cause penile erection, so it is possible that stimulating electrodes can be implanted as a treatment to stimulate penile erection.
4. Techniques for obtaining semen
Many male spinal cord injury patients have impaired fertility due to disorders of the ejaculatory process or the occurrence of retrograde ejaculation. In order to solve the problems of some patients, artificial insemination has been used internationally since the 1970s to solve fertility problems. Among the main methods of semen collection are.
(1) Toxic lentil injection: Toxic lentil is a parasympathetic inhibition agent that acts similarly to neostigmine, but with fewer side effects. Using this drug 2 mg subcutaneously and masturbation after 15 minutes, or an additional injection of neostigmine 1 mg after 30 minutes, 27% of paraplegics can obtain semen, inject it into the genitals of their spouse and cause pregnancy. Side effects are postural hypotension, tachycardia, nausea, and vomiting, which can be antagonized with atropine. The indications are that the spinal cord of T11, T12 and L1 must be intact.
② Penile vibrator stimulation: it can cause reflex ejaculation with a vibratory frequency of 60-80 Hz. patients must be after 6 months of injury, while stimulation of the sole of the foot can cause reflex hip flexion movements, and the plane of injury is above T12 to L1. Its semen quality is better than that of the electrospermia method. The main side effect is inducing excessive reflexes of the vegetative nerves.
③Electrical semen evacuation method: rectal electrical stimulation, 45-60mA, 90V, positive glare or induction. Stimulation of the medullary sympathetic efferent fibers of the inferior ventral plexus can be effective within 6 months of injury, and is also effective in patients who have failed the vibroseis method. Weaker electric fields and positive vertigo waves are also used instead of square waves, resulting in a better safety profile. Urethral intubation can also be used to address semen reflux. A small number of patients with injury planes below L2 are unable to tolerate electrical stimulation. This method is generally considered to have the highest success rate at present, but its safety and effectiveness still need further study.
④ Drug ion introduction: drug containing 25% procaine 5ml, 2% thiamine bromide 1ml, 0.05% neostigmine 1ml, placed in the lumbosacral area connected to the anode, 10-15mA, 20-25 minutes, 15 times a course of treatment.
5.Female sexual dysfunction
① Fertility: spinal cord injury has no effect on the fertility of female patients, menstruation generally returns to normal within one year, an average of 5-6 months. However, the injury itself has a significant impact on the psychology of the patient and the psychology of the spouse. Sensory impairment of the genitalia and physical activity disorders can also affect sexual life to a certain extent, requiring the use of some adaptive techniques, but most importantly, psychological counseling and treatment. Since there is no significant impairment of fertility in women with spinal cord injury, patients who need contraception should still take appropriate measures.
② Sexual response: Sexually sensitive organs are not only genitalia, but other parts such as breast, shoulder, neck, or mouth and lips can be sexually sensitive areas. In female patients, after the loss of sensation in the genitalia, the sexually sensitive area tends to shift to other areas, which is still sufficient to stimulate the production of orgasm. The external genitalia can have reflex secretions above the level of T12 and psychogenic secretions below the level of L1. Although the amount of secretion may be reduced, sexual activity is generally not significantly affected.
(iii) Comorbidities: Anemia, fluid retention, and weight gain can all make pressure sores more likely to occur during a woman’s pregnancy. An enlarged uterus may interfere with previous bowel habits. Patients with urinary incontinence may be forced to use indwelling catheters. Weight and shape changes may cause decreased independence in daily living. Be aware of the effects on the fetus when administering medications. Venous congestion in the lower extremities increases the risk of venous thrombosis. If there are recurrent urinary tract infections and residual proteinuria, the risk of pregnancy toxemia is increased. severe hypertension can occur during pregnancy in women with spinal cord injury above T6, and is related to vegetative overreflexes. medication is often ineffective, and continuous epidural anesthesia can be used to block sympathetic reflexes if necessary.
The management of labor must vary according to the level of spinal cord injury; patients with injuries above the T10 level may not be able to feel uterine contractions due to loss of sensation in the lower abdomen, and may deliver prematurely without being detected because the rupture of the amniotic membrane may be confused with urinary incontinence and cannot be distinguished. Therefore, signs of labor need to be monitored from the 28th week onwards. Non-absorbable sutures are recommended when performing perineal incision sutures to avoid infection. Hypertensive episodes can be the first sign of uterine contractions, and overactive autonomic reflexes can lead to serious consequences. Epidural anesthesia or intravenous hypotensive drugs should be considered for injury planes above T6. If the abdominal muscles are paralyzed, forceps may have to be used. If the injury site is at the T10 to 11 level, uterine contractions may be weak and a cesarean section may be necessary. Injury planes below T12 may preserve some sensation of the uterus but paralysis of the perineum. This may result in perineal tearing during delivery. Postpartum, one should also be alert for deep vein thrombosis and urinary tract infection.
6. Psychological and behavioral treatment
Successful treatment needs to include both physical and behavioral aspects. Physical disability and altered sexual function have a significant impact on a person’s sexual identity and self-esteem. Sexual desire, sexual behavior and sexual feelings are inseparable parts of the sexual functioning experience. Sexual desire, a primal desire, can be repressed by physical discomfort, pain, anxiety or the onset of disease or disability. The sexual act requires a variety of mobility and produces a pleasure response. Sexual sensation is a manifestation of sexual desire through the sexual act in a self-perceived situation. This self-perception can be influenced by past knowledge, feelings of self, and relationships with other people. Patients with spinal cord injury develop primary or secondary dysfunction in each of these areas. Primary dysfunction has an organic component such as paralysis, impotence, loss of sensation, or altered hormonal self-regulation. Secondary dysfunction is non-organic. Secondary changes occur when the patient’s attitude and anxiety affect the satisfaction of his or her sexual life.
Spasms and contractures can interfere with sexual activity, and incontinence treatment may impair libido, which can usually be avoided by proper preparation for intercourse. Fear of failure during intercourse or fear of not satisfying the other person may inhibit both partners in intercourse. The physically competent partner may fear harming a sexual partner who has a spinal cord injury. Rehabilitation education and positive encouragement will often motivate the patient to experiment and gain pleasure from sexual activity.