Women's Sexual Function and Dysfunction. Irwin Goldstein MD

Spinal cord injury

Marca L Sipski, Craig J Alexander

Our understanding of the impact of spinal cord injury on female sexual response and sexuality is probably greater than that of any other physical problem (see Chapter 16.6 of this book). Despite this fact, our understanding of and ability to document the presence of sexual dysfunction in women with spinal cord injury remain in their infancy. Moreover, our ability to treat sexual dysfunction in this population remains unproven. The goal of this chapter is to review our knowledge of the natural history of spinal cord injury in relation to female sexual response and sexuality, to discuss the diagnosis of sexual dysfunction in the population of women with spinal cord injury, and to discuss potential treatment methods currently being evaluated.

The impact of spinal cord injury on female sexuality

A number of questionnaire studies have addressed the impact of injury on women’s sexuality.1-4 As this population is heterogeneous in their neurologic injuries, these data are mainly useful in issues such as frequency of, patterns of, and satisfaction with sexual activities. The frequency of sexual activity has been shown to decrease in women after spinal cord injury.Additionally, sexual satisfaction has been shown to decrease in women after spinal cord injury.1,4 Women have not demonstrated a significant change in their sexual activities after spinal cord injury;1 however, more recent unpublished data reveal that a surprisingly low percentage of women with spinal cord injuries masturbate. This information should be considered when coming up with a plan for treatment of sexual concerns in women with spinal cord injury.

What is a spinal cord injury?

Before any discussion of the impact of spinal cord injury on female sexual response, one must understand the effects of spinal cord injury (see Chapters 4.1—4.4). Spinal cord injury can occur at any level of the spinal cord and can produce varying degrees of neurologic dysfunction.5 Depending on where the injury occurs, the person will sustain either tetraplegia, which implies some loss of neurologic function in both the arms and legs, or paraplegia, which implies only loss of neurologic function in the legs and potentially torso. Spinal cord injuries are classified according to the International Standards for Spinal Cord Injury (Figure 16.5.1).6 These standards allow us to describe a specific level of neurologic injury, the degree of motor and sensory dysfunction, and the pattern of neurologic dysfunction as determined by physical examination.

Performance of the spinal cord injury examination

A detailed neurologic assessment, using the international stan- dards,6 is of paramount importance in accurately assessing the impact of spinal cord injury on a woman’s sexual response. Specifically, one should document whether the injury is complete or not by determining whether the person has voluntary rectal contraction and/or sensation. Those with incomplete injuries would have one or both of these functions present, while those with complete injuries should have neither. Additionally, one should document whether the ability to perceive pinprick and light touch sensation in the T11—L2 dermatomes has been preserved, and quantify how much function is preserved, utilizing the international standards.6 The score for the remaining sensation in the area is a 2-point score completed for both light touch and pinprick sensation with 0 being no sensation preserved; 1, partial sensation; and 2, normal sensation. Scores are tested on both sides of the body, so that a person could have a score of 0-32 for the combined scores in both dermatomes.

The impact of the spinal cord injury on reflex function in the sacral region is also an important consequence of the injury. Spinal cord injury can result in upper motor neuron (damage to the first neuron coming down from the brain to the cord) or lower motor neuron dysfunction (damage of the second neuron going directly to the muscle) in this area. The type of injury that affects the sacral segments is determined by testing the bulbo- cavernosus reflex; that is, by inserting the finger into the rectum and then pulling on the pubic hairs or stimulating the clitoris.

Figure 16.5.1

Table 16.5.1. Female spinal sexual function classification

Function

Response

Criteria

A: Sexual dysfunction

Present

Desire disorders Arousal disorders Orgasm disorders Pain disorders

 

Absent

 

B: Psychogenic genital arousal

Intact/normal

SS = 32 T11-L2

 

Likely

SS = 16-31 T11-L2

 

Unlikely

SS = 1-15 T11-L2

 

Not possible

SS = 0 T11-L2

C: Reflex genital arousal

Intact

Normal or hyperactive BC and anal wink reflexes

 

Possible

Hypoactive or partially intact BC and/or anal wink reflexes

 

Not possible

Absent BC and anal wink reflexes

D: Orgasm

Not possible

No S2-S5 sensation; absent BC and anal wink reflexes

 

Possible

All other neurologic lesions

Reprinted with permission from Sipski and Alexander.22 (BC = Bulbocavernosus reflex; SS = sensation score)

Women with upper motor neuron injury demonstrate a quick contraction about the finger, women without neurologic injuries also demonstrate a contraction, and women with lower motor neuron complete injuries do not have any reflex contraction around the examiner’s finger. Persons with incomplete injuries should have some voluntary rectal contraction preserved regardless of whether the injury is upper motor neuron or lower motor neuron in nature.

It is important to note that the standards do not contain a description of the effects of the spinal cord injury on autonomic function. Consequently, although persons may have “complete” injuries - defined by the absence of sensory and motor function going to the anal area - they may still perceive internal, auto- nomically driven sensory experiences, such as menstrual cramps, neurogenic pain, and sometimes vague sensation of the need to move their bowels. In addition to damage to external neurologic function, there are various effects on other organ systems as a result of spinal cord injury. For instance, patients with spinal cord injury may suffer from neurogenic bowel and bladder dysfunction, both with characteristics of upper motor neuron or lower motor neuron injuries.

Effect of spinal cord injury on female sexual response

The effect of spinal cord injury on female sexual response has been evaluated in numerous laboratory-based studies.7-10 The neurologic control of sexual response relies on two separate pathways to control genital sexual arousal: a psychogenic pathway and a reflex pathway. Thus, the impact of spinal cord injury on sexual response depends on which of these pathways is affected. In order to understand most clearly and thereby treat the dysfunction, one should consider the individual and the specific pattern of injury.

In women with all levels of spinal cord injury, the control of psychogenic arousal has been studied in a laboratory with vaginal pulse amplitude11 as a means to record genital vasocon- gestion. In women with all levels of injury, the ability to achieve psychogenic genital arousal has been shown to be related to the preservation of the ability to perceive pinprick and light touch sensation in the T11-L2 dermatomes.6 Those women with combined scores of 24-32 in these dermatomes were significantly more likely to demonstrate psychogenic genital vasocongestion than women with scores of 9-23. Moreover, women with scores of 9-23 were significantly more likely to achieve psychogenic vasocongestion than those with scores of 0-8. Practically speaking, these dermatomes include the area between the umbilicus and the middle of the thigh, so that women with spinal cord injury that have better sensation in these areas have a greater likelihood of achieving genital arousal through psychogenic stimulation, such as watching sensual movies, kissing, or hearing or reading erotic passages.

The control of reflex arousal has also been studied in the laboratory. Women with spinal cord injury who were first subjected to psychogenic stimulation and then to manual stimulation were shown to have further increases in their level of genital arousal by manual stimulation regardless of whether they had concomitant increases in their level of subjective arousal.3,5 This is thought to be evidence of the maintenance of reflex genital arousal in women with upper motor neuron injuries affecting their sacral spinal segments. Further research also compared the effect of the addition of manual stimulation to psychogenic stimulation in women with upper motor neuron versus lower motor neuron injuries affecting their sacral segments.10

Results revealed greater increases in vaginal pulse amplitude (see Chapter 10.1) and thus genital vasocongestion in the group with upper motor neuron injuries; however, these findings were not statistically significant. Despite the lack of significance in these results, the overall psychophysiologic data tend to validate the hypothesis that reflex lubrication should be preserved in women with upper motor neuron injuries affecting their sacral segments, and that women with lower motor neuron incomplete injuries should still have partial preservation of reflex lubrication. The only subset of women who should not have the potential for reflex lubrication would be women with complete lower motor neuron injuries.

The ability to achieve orgasm in women with spinal cord injury has also been assessed via questionnaire studies and in the laboratory.12,13 In the largest laboratory-based series to date,6 the ability to achieve orgasm was found to be significantly diminished in women with complete lower motor neuron injuries affecting their sacral spinal cord (see Chapter 6.4). Women with all other levels and degrees of spinal cord injury were significantly less likely than able-bodied control subjects to achieve orgasm. Fifty-five percent of women with spinal cord injury reported the ability to achieve orgasm as opposed to 100% of able-bodied control subjects, and 44% of spinal cord injury subjects were orgasmic in the laboratory as opposed to 100% of able-bodied controls. These results were taken as evidence that the occurrence of orgasm depends on the presence of an intact sacral arc.

The authors also noted that when two of the investigators were masked to the subjects’ descriptions of orgasms they were unable to distinguish whether the women had complete or incomplete spinal cord injury, or were able-bodied control subjects. This finding, in addition to the above, led to the hypothesis that orgasm is a reflex response of the autonomic nervous system that can be either facilitated or inhibited by cerebral input.

Other recent research also points to the fact that orgasm may be associated with a pattern generator in the spinal cord. The suggestion has been made that an ejaculation generator is present in the spinal cord14 of male rats. These researchers also documented activation of a subset of lumbar spinothalamic neurons after copulatory behavior in male, but not in female, rats.15 This finding in male rats is similar to that of the urogenital reflex that is found in spinalized, anesthetized animals above T9. It comprises rhythmic firing of the hypogastric, pelvic, and pudendal motor nerves;16,17 and appears to be similar to the finding of orgasm in women with spinal cord injury. The peripheral activity displayed during the urogenital reflex strongly resembles that seen during human orgasm.18 Vaginal, uterine, and anal sphincter rhythmic contractions are present in both the urogenital reflex and orgasm, and both are relatively insensitive to gonadal hormones.

The characteristics of orgasm in able-bodied versus spinal cord injury subjects were also analyzed. Despite previous reports that nongenital stimulation is often used as a means to achieve orgasm, only one woman in this study10 chose nongenital stimulation in combination with genital stimulation. The average latency to orgasm was significantly greater in spinal cord injury than able-bodied subjects (26 vs 16 min). The heart rate, systolic blood pressure, and respiratory rate at orgasm compared to baseline were significantly greater for both spinal cord injury and able-bodied subjects; however, there were no significant differences between groups at any time period. Diastolic blood pressure was similar in both groups of subjects at orgasm and baseline; moreover, there was no significant increase in diastolic blood pressure at orgasm versus baseline.

The authors hypothesized that if the neurologic potential to achieve orgasm exists in approximately 50% of women with all levels of spinal cord injuries, then those women who did not achieve orgasm must have some intervening variable precluding them from achieving orgasm. Lack of education and interfering psychologic issues were mentioned as possible problems, in addition to the overall negative viewpoint in the medical literature that has previously existed.19,20 Therefore, the authors concluded that women with spinal cord injury should be instructed that a longer and more intense degree of genital stimulation may be necessary to achieve orgasm, and that the development of treatment methods to remediate orgasmic dysfunction is warranted.

Documentation of sexual dysfunction in women with spinal cord injury

The above documentation of the impact of spinal cord injury on sexual response provides a framework for understanding how the injury affects sexual response (see Chapters 10.5 and 10.6). But it does not give us any information about whether a woman with a spinal cord injury has sexual dysfunction. According to the International Consensus Development Conference on Female Sexual Dysfunction,21 in order for patients to have sexual dysfunction they must complain of personal distress. Therefore, a woman with spinal cord injury could have alterations in her sexual response related to her injury but still not complain of distress and therefore not have sexual dysfunction. In addition, a woman with spinal cord injury could have no injury-related alterations in her sexual response but still complain of sexual distress and thus suffer from sexual dysfunction. In order to remedy this lack of a means of documentation, the “female spinal sexual function classification” was proposed.22 This classification system relies on previous research to define four categories of sexual function after spinal cord injury, and document their presence, the associated characteristics, and which aspects of the neurologic examination should be used to determine the likely response (Table 16.5.1). From the neurologic examination and detailed history, one should be able to document the expected effects of the injury on specific components of sexual response and also document whether the subject reports any sexual dysfunction. This latter issue becomes especially important when the issue of clinical trials for remediation of sexual dysfunction after spinal cord injury is addressed. The female spinal sexual function classification is currently being utilized in a study of women with spinal cord injuries and multiple sclerosis in order to assess its utility for documentation of the remaining sexual function and presence or absence of sexual dysfunction in women with spinal cord injury.

Improving sexual responsiveness

The PLISSIT model23 offers specific suggestions for initiating and maintaining discussions for sexual counseling. The PLISSIT model describes the process of permission, limited information, specific suggestions, and intensive therapy/ counseling. This is a useful model for describing how to address the issue of talking about sexuality with women with spinal cord injury, and it underscores the importance of education about changes in sexual response and sexuality that occur after spinal cord injury. Education about the impact of injury on sexual response is the first and probably most important thing that needs to be done to improve the sexual responsiveness of women with spinal cord injury. In light of this need, a consumer-friendly video about the impact of spinal cord injury on female sexual response was recently made available.24

Education alone will probably help a number of women with spinal cord injury to improve their sexual response. However, some women will need more intensive therapy.

A number of studies have begun to develop therapies to improve sexual responsiveness in women with spinal cord injury. The majority of these studies have been based on treatments previously used in able-bodied women, although one drug study was based upon testing the efficacy of medications utilized in men.25

The first series of therapies can be described as psychologic in nature. False-positive feedback was used in a laboratory-based study26 to increase the level of sexual arousal in a sample of women with spinal cord injury. It is unknown whether these women complained of sexual dysfunction or not. In this study, false-positive feedback was shown to increase psychogenic arousal in both complete and incomplete spinal cord injury. However, genital arousal was increased only in women with incomplete injuries who had preservation of sensory function in the T11-L2 dermatomes. This study concluded that psychologically based treatments may help to improve function in this subset of women with spinal cord injury.

In another study, the same authors investigated the impact of an anxiety-provoking video on sexual arousal.27 Subjects viewed two erotic videos, one of which was preceded by exposure to a neutral video, while the other was preceded by exposure to an anxiety-provoking video. In subjects with impaired genital responsiveness to psychogenic erotic stimulation (T11-L2 combined American Spinal Injury Association scores less than 23), anxiety pre-exposure resulted in a small increase in genital responsiveness to erotic stimulation as compared to neutral preexposure. For those subjects who had mostly intact genital responsiveness (spinal cord injury subjects with T11-L2 combined American Spinal Injury Association scores greater than 23) and able-bodied subjects, anxiety pre-exposure resulted in decreased genital responsiveness as compared to neutral preexposure. The authors concluded that these results document the potential usefulness of manipulation of the sympathetic nervous system in subjects with impaired, but not absent, ability to achieve psychogenic genital vasocongestion. In addition, the authors noted that these data are further evidence of the regulatory role of the sympathetic nervous system in psychogenic arousal.

Only one published study has looked at the effects of medications on sexual responsiveness after spinal cord injury in females. In a laboratory-based, double-blind, crossover-design study,17 the effects of sildenafil 50 mg versus placebo were compared on vaginal pulse amplitude, subjective arousal, and autonomic function. Subjects underwent a 78-min protocol in which audiovisual erotic stimulation and audiovisual erotic combined with self-applied manual stimulation were experienced. A statistically significant increase in subjective arousal was noted with the use of the medication in addition to the sexual stimulation conditions. A borderline significant effect of drug administration was noted on vaginal pulse amplitude. Modest increases in heart rate (±5 beats/min) and blood pressure (±4 mmHg) were also documented.

Although the above studies begin to outline some possible methods of treatment for sexual arousal dysfunction in women with spinal cord injury, data are still preliminary and have yet to be translated into clinical utility. Other studies currently in progress will examine the effect of medical sympathetic stimulation on sexual responsiveness. As new medications, such as the testosterone patch, become available, it will be warranted to assess their effects on sexual desire and arousal dysfunction after spinal cord injury.

With regard to orgasmic dysfunction after spinal cord injury, we are unaware of any previous clinical trials designed to treat this problem. If the orgasm is a reflex response of the autonomic nervous system and if a spinal pattern generator exists, it may be possible to train the pattern generator. This concept is similar to work that is being done on ambulation training28,29 and is the foundation for a study to test the efficacy of EROS therapy30 versus vibratory stimulation that is currently underway. Both of these therapies that are designed to stimulate a reflex response should be useful to treat sexual dysfunction in women with spinal cord injury. Until the results of this research are available, either method could be considered potentially useful as a supplement to targeted sexual education in women with spinal cord injury and sexual dysfunction.

As compared to other neurologic injuries, our knowledge of the impact of spinal cord injury on female sexual response is relatively advanced. We have recently begun a study of predominantly women with spinal multiple sclerosis to see whether the impact on sexual response in women with spinal lesions as a result of multiple sclerosis is similar to that of spinal cord injury. It is hoped that our knowledge about the impact of spinal cord injury on female sexual response can serve as a model to study not only multiple sclerosis but also other neurologic disabilities.

Acknowledgment

This work was supported in part by funds from the US National Institutes of Health, R01 HD 30149.

References

1. Sipski ML, Alexander CJ. Sexual activities, response and satisfaction in women pre- and post-spinal cord injury. Arch Phys Med Rehabil 1993; 74: 1025-9.

2. Charlifue SW, Gerhart KA, Menter RR et al. Sexual issues of women with spinal cord injuries. Parapgga 1992; 30: 192-9.

3. Jackson AB, Wadley V. A multicenter study of women’s selfreported reproductive health after spinal cord injury. Arch Phys Med Rehabil 1999; 80: 1420-8.

4. Fisher TL, Laud PW, Byfield MG et al. Sexual health after spinal cord injury: a longitudinal study. Arch Phys Med Rehabil 2002; 83: 1043-51.

5. Staas WE, Formal CS, Freedman MK et al. Spinal Cord Injury and Spinal Cord Injury Medicine in Rehabilitation Medicine: Priniciples and Practice, 3rd edn. Philadelphia: DeLisa & Gans, 1993: 1259-91.

6. American Spinal Injury Association. International Standards for Neurological and Functional Classification of Spinal Cord Injury, revised. Chicago: American Spinal Injury Association, 1992.

7. Sipski ML, Alexander CJ, Rosen RC. Physiologic parameters associated with psychogenic sexual arousal in women with complete spinal cord injuries. AïshPyMedRhüM 1995; 76: 811-18.

8. Sipski ML, Alexander CJ, Rosen RC. Physiologic parameters associated with the performance of a distracting task and genital selfstimulation in women with complete spinal cord injuries. Arch Phys Med Rehabil 1996; 77: 419-24.

9. Sipski ML, Alexander CJ, Rosen RC. Physiologic parameters associated with psychogenic sexual arousal in women with incomplete spinal cord injuries. Arch Phys Med Rehabil 1997; 78: 305-13.

10. Sipski ML, Alexander CJ, Rosen RC. The neurologic basis of sexual arousal and orgasm in women: effects of spinal cord injury. Ann Neurol 2001; 49: 35-44.

11. Lann E, Everaerd W. Physiological measures of vaginal vasocon- gestion. Int J Impot Res 1998; 10: 107-10.

12. Sipski ML, Alexander CJ, Rosen RC. Orgasm in women with spinal cord injuries: a laboratory-based assessment. Arch Phys Med Rehabil 1995; 76: 1097-1102.

13. Whipple B, Gerdes CA, Komisaruk BR. Sexual response to selfstimulation in women with complete spinal cord injury. J Sex Res 1996; 33: 231-40.

14. Truitt WA, Coolen LM. Identification of a potential ejaculation generator in the spinal cord. Science 2002; 297(5586): 1566-9.

15. Truitt WA, Shipley MT, Veening JG et al. Activation of a subset of lumbar spinothalamic neurons after copulator behavior in male but not female rats. J Neurosci 2003; 23: 325-31.

16. Chung SK, McVary KT, McKenna KE. Sexual reflexes in male and female rats. Neurosci Lett 1988; 94: 343-8.

17. McKenna KE, Chung SK, McVary KT. A model for the study of sexual function in anesthetized male and female rats. Am J Physiol 1991; 30: R1276-85.

18. Bohlen JG, Held JP, Sanderson MO et al. The female orgasm: pelvic contractions. ArchA^x^^tav 1982; 11: 367-86.

19. Money J. Phantom orgasm in the dreams of paraplegic men and women. Arch Gen Psychiatry 1960; 3: 373-82.

20. Fitting M, Salisbury S, Davies N et al. Self-concept and sexuality of spinal injured women. Arch Sex Behav 1978; 7: 143-56.

21. Basson R, Berman J, Burnett Aetal. Report of the international consensus development conference on female sexual dysfunction: definitions and classification. J Urol 2000; 163: 888-93.

22. Sipski, ML, Alexander CJ. Documentation of the impact of spinal cord injury on female sexual function: the female spinal sexual function classification. Top Spinal Cord Inj Rehabil 2002; 8: 63-73.

23. Annon J. The Behavioral Treatment of Sexual Problems: Brief Therapy. New York: Harper & Row, 1976.

24. Sipski ML. Women’s Sexuality After SCI: Understanding the Changes and Finding Ways to Respond. Video, 2003.

25. Sipski ML, Rosen RC, Alexander CJ et al. Sildenafil effects on sexual and cardiovascular responses in women with spinal cord injury. Urology 2000; 55: 812-15.

26. Sipski ML, Rosen R, Alexander CJ et al. A controlled trial of positive feedback to increase sexual arousal in women with spinal cord injuries. NeuroRehabilitation 2000; 15: 145-53.

27. Sipski ML, Rosen RC, Alexander CJ et al. Sexual responsiveness in women with spinal cord injuries: differential effects of anxiety- eliciting stimulation. Arch Sex Behav 2004; 33: 295-302.

28. Wernig A, Muller S, Nanassy Aetal. Laufband therapy based on “rules of spinal locomotion” is effective in spinal cord injured persons. EurJNeuoci 1995; 7: 823-9.

29. Wernig A, Nanassy A, Muller S. Maintenance of locomotor abilities following Laufband (treadmill) therapy in para- and tetraplegic persons: follow-up studies. SpmalÇord 1998; 36: 744-9.

30. Billups KL, Berman L, Berman Jetal. A new non-pharmacological vacuum therapy for female sexual dysfunction. J Sex Marital