Human Sexuality

Sexuality encompasses a broad spectrum beyond mere genitality; this includes sex, gender identities, sexual orientation, eroticism, pleasure, intimacy, and reproduction. This multidimensional aspect of the human experience is shaped by a myriad of influences, including biological, psychological, social, economic, political, cultural, legal, historical, religious, and spiritual factors. Individuals navigate their sexuality through a complex interplay of thoughts, fantasies, desires, attitudes, values, behaviors, practices, roles, and relationships, all influenced by diverse contextual factors.

In discussing sexuality, it is essential to grasp critical concepts such as sex, erotism, and gender identity. An individual’s genetic and genital makeup at birth dictates their sex and reproductive functions. Erotism encompasses desires, emotions, behaviors, and interactions expressed with partners or during solitary experiences of sexual fulfillment. Amatory pertains to the physical manifestations of eroticism and its associated elements. Gender identity reflects an individual’s internal sense of their gender, which may or may not align with the sex assigned to them at birth. ^,

Sexuality and Disabilities

The human condition makes us sexual beings, and the exercise of rights related to sexuality acquires essential relevance. Throughout history, the sexuality of people with disabilities has been associated with invisibility, censorship, pathologization, denial, and violation of intimate spaces, and the inability to make autonomous decisions about their bodies. Individuals with disabilities are often viewed as asexual due to predominant heteronormative ideas about sex. Lack of information and education about sexuality and disability contributes to the stigma attached to these 2 entities.

Mechanisms of exclusion and overprotection lead to the categorization of normal and abnormal, which influences the perception of sexuality. When perceived as abnormal, it has historically been associated with people with disabilities, leading to limitations in experiencing pleasure, intimacy, and different approaches to enjoyment for these individuals. Furthermore, the societal construction of bodies deemed “invalid” has perpetuated narrow standards of beauty and normalcy, emphasizing productivity above other qualities. In health care settings, the focus has traditionally centered on addressing sexual dysfunction rather than embracing and supporting the full spectrum of sexuality for people with disabilities.

Sexuality in Individuals with Spinal Cord Injury

Individuals with SCI experience physical and psychological consequences that profoundly affect their sexual health. It is well documented in the literature that there is a high prevalence of sexual difficulties in people with SCI. A link has also been established between the sexual problems of this population and decreased quality of life. Sexuality is a central and fundamental aspect of the lives of people with SCI and their families. Due to all the physical and psychological consequences that an SCI entails, individuals with SCI must adapt to a new way of life, facing losses and challenges. This is particularly relevant, especially in sexuality, where these individuals experience loss of sensation, body image difficulties, sexual dysfunction, changes in sexual responses, and relationship dynamics, among others. Unfortunately, for many years, rehabilitation professionals have not prioritized addressing all these issues in rehabilitating these individuals. Therefore, there is often a significant gap in providing support, education, and resources regarding sexual concerns and needs to help individuals with SCI explore new ways of experiencing intimacy and sexual fulfillment.

Regardless of whether SCI is congenital or acquired, the approach to sexuality should focus not only on medically treating sexual dysfunction but also on educating the individual and their family about sexual health. Factors such as age, gender, level of education, religion, cultural values and beliefs, and level of injury, among others, should be considered during educational and rehabilitation interventions. For instance, an individual who had an SCI at the age of 15 years will not have the exact sexual needs of another who is married and had the SCI when he or she was aged 35 or 65 years. Another example to consider is what happens in cultures where polygamy is practiced and men’s sexuality is valued more than women’s. Therefore, addressing the issue of sexuality in a person with SCI takes on another dimension in these sociocultural contexts.

The effect of SCI on sexual response varies based on its severity and location. In addition, the exploration of sexual response is contingent upon factors such as gender identity and the specific aspect under investigation. Predominantly, insights into male sexual response stem from questionnaire-based studies, whereas our understanding of female sexual response predominantly originates from laboratory research. Moreover, besides alterations in sensitivity in the genital area and issues related to orgasm, men frequently encounter erectile and ejaculatory dysfunctions, while women may experience variations in lubrication. Since sexual responses are organized at the spinal level, people may report different sexual dysfunctions according to the neurologic level of injury. The integrity of 2 spinal segments is essential for sexual function. On the one hand, the T11–L2 sympathetic center is responsible for psychogenic sexual arousal (psychogenic erection in men and genital vasocongestion in women) and emission of semen in men with impulses traveling through the hypogastric nerves. On the other hand, the S2–S4 parasympathetic center mediates reflex sexual arousal through fibers of the pelvic nerve and the S2–S4 somatic center and, along with fibers of the pudendal nerve, supplies the pelvic floor’s striated muscles. This tract is responsible for involuntary rhythmic contractions of perineal muscles, anal sphincter, and reproductive organs during orgasm and projectile ejaculation in men. Sexuality is susceptible to various influences beyond just dysfunction in the sexual organs. Additionally, alterations in body image and the potential for unexpected issues related to SCI, such as incontinence during intercourse, can indirectly impact sexual experiences. Consequently, the repercussions are both physical and psychological.

Sexual Dysfunction in Men with Spinal Cord Injury

The sexual response cycle consists of excitement, plateau, orgasm, and resolution. Penile erection is initiated by visual, olfactory, or imaginative stimuli impinging upon supraspinal centers or by genital stimulation activating spinal reflex mechanisms. Erection involves arteriolar dilatation and increased blood flow to the erectile tissue of the penis.

Men can experience 3 types of erections: Psychogenic erections, reflexogenic erections, and nocturnal erections. Psychogenic erection originates in the brain: a stimulus received through any sense (such as smell, touch, or hearing) is transmitted to the brain, which sends signals through the spinal cord to stimulate a penile erection. A reflexogenic erection is involuntary and can happen due to direct physical contact with the penis or other erogenous zones. A nocturnal erection is an automatic penile erection that occurs during sleep or upon waking, serving as a mechanism to maintain penile function.

Specifically to erections, the pudendal nerve carries sensory information from the genital, perineal, perianal, and scrotal skin to the sacral cord (S2–S3–S4). Embryologically, the testes develop internally at the same level as the kidneys and, therefore, share a common level of innervation (T10–L1) after descending into the scrotal sac (lower temperature required for spermatogenesis); the somatic branches of L1–L2 and S2–S3 innervate the scrotal skin. Ejaculation is the process of external semen expulsion. It is primarily a sympathetic phenomenon (T10–L2) involving specific afferent sensory pathways, cerebral and spinal integrative, autonomic, somatic centers, and efferent pathways.

The majority of male individuals with SCI who experience erectile dysfunction (ED) can be treated based on their medical and sexual history, in addition to a precise physical examination. In this scenario, comprehensive interviews are crucial for each patient: the provider should assess how ED affects the patient’s daily life, the necessity for treatment, and psychosocial factors that could impact ED or be impacted by it. It is also vital to review any other health conditions, current medications, and lifestyle habits such as smoking, diet, and exercise, as these factors could affect sexual function. Even though the majority of men with SCI experience some form of ED, those able to achieve erections note that the quality of their erections is inadequate for intercourse. There are nonpharmacological and pharmacologic treatments for sexual dysfunction in men with SCI. When an erection is not possible, patients are often encouraged to explore sexual practices that are not erection-dependent, such as oral sex and mutual masturbation. The approach to addressing ED involves nonpharmacological aids to regain sexual function. The level of injury, hand function and dressing skills, and potential interactions with various medications need to be considered.

Pharmacologic options can be taken orally, applied through the urethra, or directly into the penis. Oral phosphodiesterase type 5 inhibitors (PDE5Is), such as sildenafil, tadalafil, vardenafil, and avanafil, are currently recommended as the primary treatment of neurogenic ED in men. The efficacy of these medications in managing ED is contingent upon the extent and location of the neurologic injury. These medications can be utilized either on-demand, exemplified by sildenafil at 50 to 100 mg taken 30 to 60 minutes before engaging in sexual activity, or on a chronic basis, as illustrated by tadalafil at 20 mg every 48 hours.

Intracavernosal injections (ICIs) involve using single or multiple specific drugs, such as prostaglandin E1 (also applied intraurethrally), papaverine, and phentolamine. ICIs are considered a viable alternative in cases of PDE5I failure or as a first-line treatment when there are contraindications to PDE5Is (eg, use of nitrate medications). Particularly, patients with SCI at lower lesion levels may respond better to ICI than to oral pharmacotherapy due to the absence of preservation of sacral reflex. However, ICIs are associated with pain, especially in cases of incomplete SCI, hematoma, particularly under antithrombotic therapy, or fibrosis of the corpora cavernosa.

A vacuum erection device (VED) uses negative pressure to distend the corporal sinusoids and to increase blood inflow to the penis. Depending on its intended use, VED may be employed alongside an external constricting ring positioned at the penis base to inhibit blood outflow, thereby sustaining an erection during sexual intercourse. Alternatively, VED can be utilized without a constriction ring solely to enhance blood oxygenation to the corpora cavernosa. The device should not be utilized for more than 30 minutes, as prolonged use may lead to reduced blood flow, potentially resulting in necrosis of the penile skin and other injuries. Additionally, using the device concurrently with anticoagulation medication is contraindicated. Despite these potential adverse effects, over 90% of users reported achieving an erection-like state satisfactory for coitus. Sidi and colleagues found an overall satisfaction rate of 68% with the VED, with pain, inconvenience, and premature loss of rigidity cited as reasons for dissatisfaction. ^,

For those facing challenges with the VED, penile prosthesis (PP) may offer a viable solution. PPs come in 2 types: inflatable and malleable. Malleable prostheses consist of semirigid cylinders that can be bent upward during sexual intercourse. Implantable PPs consist of 2 cylinders, a reservoir balloon, and a pump placed in the scrotum, allowing fluid transfer for an erection. These devices may be recommended for individuals with SCI to address various needs, including keeping an external condom catheter in place, supporting penis positioning during intermittent catheterization for those with impaired hand function, and facilitating erections sufficient for intercourse.

Other nonpharmacological options include sacral neuromodulation, with limited efficacy in erectile function improvement. Sacral deafferentation and anterior root stimulation (SDAF/SARS) shows promise in bladder and bowel management and potential improvement in ED. However, SDAF/SARS is an invasive procedure, and rhizotomy may lead to complete ED, limiting its application in patients with complete SCI. ^,

The authors recommend the early and chronic use of PDE5Is to preserve penile tropism and sexual function. Additionally, VEDs may be used for 5 to 10 minutes daily for 3 months and later in conjunction with a constriction ring. ICIs are effective and should be administered after proper training to minimize the risk of hematoma. However, for young patients desiring an active sexual life, PP implantation may be considered to reduce the risk of hematoma with repeated injections, prevent fibrosis of the corpora cavernosa, and facilitate a more natural sexual experience. The authors advocate using inflatable PP to minimize the risk of extrusion/erosion and urethral damage, especially in intermittent catheterizations.

Orgasm and ejaculation are 2 separate physiologic processes. Orgasm is an intense peak sensation of pleasure associated with altered consciousness, while ejaculation is a complex process involving emission and expulsion phases influenced by neurologic and hormonal pathways. ^, Men with SCI can still achieve orgasm, although the frequency may be lower compared to able-bodied individuals. Research indicates that men with SCI are less likely to achieve orgasm, but the characteristics of orgasm in men with SCI are similar to those in able-bodied subjects. Additionally, men with incomplete SCI are more likely to achieve orgasm than those with complete SCI. It has been found that there is a pattern generator in the spinal cord for ejaculatory function, suggesting the possibility of retraining ejaculatory and orgasmic responses in men with SCI.

Ejaculation in men with SCI can be significantly affected. After an SCI, ejaculation may require more stimuli to trigger sexual reflexes. Penile vibratory stimulation (PVS) is a common first-line treatment that induces strong nerve stimulation and activates the autonomic nervous system. Additionally, oral midodrine can enhance the success rate of PVS as an adjunct treatment. Electroejaculation is successful in cases where PVS fails, but it may result in lower sperm motility rates than PVS. In men with SCI, coordination between external and internal sphincters is crucial for ejaculation, and a supraconal lesion can lead to dyssynergic ejaculation.

Sexual Dysfunction in Women with Spinal Cord Injury

The female sexual response cycle consists of 4 phases: desire, arousal, orgasm, and resolution. Each phase involves physical and emotional changes that occur during sexual activity.

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  Desire phase: This phase involves an increase in heart and breathing rates, nipple erection, clitoral and vaginal swelling, skin flushing, muscle tension, and vaginal lubrication;

  
  
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  Arousal phase: Preceding orgasm, this phase includes continued physical changes from desire, such as increased clitoral sensitivity, muscle tension, vaginal swelling, and color changes in the vagina;

  
  
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  Orgasm phase: The climax of the cycle is characterized by muscle contractions, increased heart rate and blood pressure, release of tension, and the release of endorphins. In women, there are vaginal and uterine muscle contractions;

  
  
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  Resolution phase: The body returns to its unaroused state with decreased heart rate and blood pressure, reduced swelling, relaxed muscles, a sense of well-being, intimacy enhancement, and potential fatigue. Some women can quickly return to orgasm with further stimulation.

Sexual responses such as clitoral and vaginal vasocongestion and sexual climax are organized at the spinal level. ^, The component of the sympathetic nervous system (S2–S4) is crucial for clitoral erection to occur. The spinal systems generating sexual responses can be excited or inhibited by peripheral sensory stimuli. A major afferent pathway travels in the pudendal nerve and is responsible for transmitting sexual stimuli from the external genitals and perineum. The spinal sexual reflex mechanisms are under descending excitatory and inhibitory control from the brainstem and hypothalamic sites, and they are relatively unaffected by gonadal hormones.

When the orgasm happens, the body releases tension, and the perineal muscles, anal sphincter, and reproductive organs rhythmically contract. Even though it is a neurologic phenomenon, the neural circuits are poorly understood.

After SCI, physical aspects such as body image affectivity and intimacy are preponderant to achieve a joyful sexual life. For those women who are able to overcome the physical restrictions and mental obstacles due to an injury, it is possible to regain an active and positive sexual life together with their partner.

As for organic alterations, 1 in 4 women with SCI experiences decreased vaginal lubrication. Nonpetroleum and fragrance-free hydrophilic lubrication gels are essential, along with frequent checks for skin breakdown, as patients may not feel discomfort.

Although, nowadays, we have several treatments for sexual dysfunction, both in men and women, it is important to keep in mind that health professionals must address sexuality as a whole. It is still a critical issue, especially due to the lack of comfort of professionals when talking about the topic, as well as the lack of information and training regarding when to speak about sexuality and how to do it. People with SCI usually report that they are not comfortable initiating discussions about sexuality. An effective therapeutic approach employs the PLISSIT model, emphasizing a structured sequence of approaches, information gathering, therapeutic alliance building, and targeted intervention.

The PLISSIT model was created by Annon, a psychosexual therapist, in 1976, to guide health care providers regarding the most effective strategies to treat sexual aspects and at the same time to facilitate communication when there is a need to refer them to more specialized advice/treatment. ^,

Annon developed a simple model that illustrates the fact that most sexual problems do not need an intensive course of therapy. He used the acronym “PLISSIT” for 4 possible levels of intervention in sexual problems, these being: “permission,” “limited information,” “specific suggestions,” and “intensive therapy.” According to Annon, most people who have sexual problems can resolve them if they are given “permission” to be sexual, desire sexual activity, and discuss sexuality, and if they receive “limited information” about issues related to sexuality and “specific suggestions” on how to address sexuality problems. This model has been recommended for use in different conditions such as myocardial infarction, cancer, and SCI, among others. Later, the EX-PLISSIT model was developed, an extension of the original. It emphasizes the role that permission-giving plays at all stages; therefore, each stage of limited information, specific suggestions, and intensive therapy is underpinned by permission-giving.

Women with SCI may report reduced libido and/or clitoral congestion. In these cases, they may benefit from specific medicines, even if there are less medical treatments for female sexual dysfunctions than in male ones. In clinical practice, the most used drugs are testosterone for restoring physiologic libido and PDE5Is for increasing clitoral congestion and lubrication. These treatments have not been studied in this population, so the authors advocate the design of multicenter randomized controlled trials to define their roles in SCI.