Sexual Response in Women With SCI
While it is true that women with SCI have clinically significant impairment in arousal and orgasm, women with complete SCI have been self-reporting orgasm that seemed physiologically impossible (Richards et al. 1997). Multiple laboratory-based studies have documented the presence of sexual arousal and orgasm in women with SCI (Whipple & Komisaruk 2002; Komisaruk et al. 2004, Sipski et al. 1995, 2000, 2004, 2005). Following SCI, women may attain genital sexual arousal through a psychogenic and/or a reflex pathway. Preservation of T11-L2 sensory dermatomes is associated with psychogenically mediated genital vasocongestion and lubrication (Sipski et al. 1997; Sipski et al. 2001). The ability to achieve reflexogenic genital congestion and orgasm depends on the presence of an intact sacral reflex arc (Sipski et al. 1997; Sipski et al. 2001). The vagus nerve has also been hypothesized to serve as a pathway that bypasses the spinal cord and thereby may facilitate those responses (Komisaruk et al. 2004).
Women with SCI are less likely to achieve orgasm than able-bodied women, and time to orgasm is significantly increased compared to able-bodied controls (Sipski et al. 2001). The ability to achieve orgasm, however, seems unrelated to the pattern or degree of neurological impairment in women with lesions down to T5 level (Sipski et al. 1995). On the other hand, women with LMN lesions affecting S2-S5 segments were less likely to achieve orgasm compared with women who had other types of SCI lesion (Sipski et al. 2001).
Similar cardiovascular responses were found in women with SCI compared to able-bodied controls at time of orgasm (Sipski et al. 1995; Sipski et al. 1996). Another study found only significant increase in blood pressure, but not in heart rate, in women with complete SCI above T10 level in response to self-stimulation, however, not all women stimulated to orgasm (Whipple et al. 1996). Greater knowledge about sexuality seems to be related to sexual responsiveness (Sipski et al. 1995).
A number of treatments to improve sexual responsiveness in women with SCI have been explored over the past decade. Two therapies were based on the assumption that psychogenic genital vasocongestion is under control of the sympathetic nervous system and that sympathetic activation may lead to enhanced sexual arousal (Sipski et al. 2000, 2004). Positive feedback was shown to increase psychogenic arousal in women with SCI, and furthermore, increased genital arousal in those women who had preservation of sensory function in the T11-L2 dermatomes (Sipski et al. 2000). In another study, anxiety-eliciting videos were used to elicit sympathetic activation (Sipski et al. 2004). Anxiety pre-exposure resulted in a small increase in genital responsiveness to erotic stimulation in subjects with impaired, but not absent, ability to achieve psychogenic genital vasocongestion (those with T11-L2 sensory score < 23). While these two studies help to understand the role of the sympathetic nervous system in mediating sexual arousal in women with SCI, clinical application of these two approaches has yet to be determined. Sipski et al. (2005)studied the effect of vibratory stimulation on sexual arousal in women with SCI. Vibratory clitoral stimulation resulted in increased genital responsiveness as compared with manual clitoral stimulation, although the differences were not statistically significant. One randomized controlled trial tested the effect of sildenafil 50mg versus placebo on sexual responsiveness (Sipski et al. 2000). Sildenafil administration improved both subjective and physiologic measures of sexual arousal. The effect was most evident under optimal stimulation conditions (manual combined with visual).
Further studies are required to investigate augmenting sexual arousal responses in women with SCI by combining psychological, physical/physiological and pharmacological approaches.
Discussion
A survey of 105 women with SCI in Iran found that women with SCI reported significantly higher levels of sexual dysfunction compared with normal controls. Of all the participants in this study, 88% of SCI patients reported at least 1 type of sexual dysfunction, whereas only 37% of healthy controls reported sexual dysfunction. Lack of vaginal lubrication was reported more frequent in SCI patients compared with controls. Women with SCI reported a significantly higher level of sexual distress compared with healthy women (Hajiaghababaei et al. 2014). A US interview study with women with SCI reported that the lack of bowel and bladder control was especially problematic for women who were developing new intimate relationships (Fritz et al. 2015).
Vibratory and manual clitoral simulation in women with SCI improved sexual arousal (Sipski et al. 2005). Small studies (Sipski et al. 2000) have evaluated the use of sildenafil (Viagra) 50 mg in women with SCI and reported promising increases in subjective arousal especially when combined with manual and visual stimulation. However, a larger study (Alexander et al. 2011) with a sample size of 126 found that sildenafil lacked clinically meaningful benefits for women with SCI, as found similarly with other populations of women.
Conclusion
There is level 1b (Alexander et al. 2011) evidence that sildenafil does not result in clinically meaningful benefits in women who have sexual arousal disorder as a result of SCI.
There is level 2 evidence (from 1 weak RCT: Sipski et al. 2005) that supports the use of manual and vibratory clitoral stimulation to increase genital responsiveness in women with SCI.
There is level 5 evidence (Moreno-Lozano et al. 2016; Hajiaghababaei et al. 2014; Fritz et al. 2015) that women with SCI reported significantly higher levels of sexual dysfunction and sexual distress compared with able-bodied controls.
