Serial MR imaging with MS-325 for evaluating female sexual arousal response: determination of intrasubject reproducibility

Pleasurable and problematic receptive anal intercourse and diseases of the colon, rectum and anus

The ability to experience pleasurable sexual activity is important for human health. Receptive anal intercourse (RAI) is a common, though frequently stigmatized, pleasurable sexual activity. Little is known about how diseases of the colon, rectum, and anus and their treatments affect RAI. Engaging in RAI with gastrointestinal disease can be difficult due to the unpredictability of symptoms and treatment-related toxic effects. Patients might experience sphincter hypertonicity, gastrointestinal symptom-specific anxiety, altered pelvic blood flow from structural disorders, decreased sensation from cancer-directed therapies or body image issues from stoma creation. These can result in problematic RAI - encompassing anodyspareunia (painful RAI), arousal dysfunction, orgasm dysfunction and decreased sexual desire. Therapeutic strategies for problematic RAI in patients living with gastrointestinal diseases and/or treatment-related dysfunction include pelvic floor muscle strengthening and stretching, psychological interventions, and restorative devices. Providing health-care professionals with a framework to discuss pleasurable RAI and diagnose problematic RAI can help improve patient outcomes. Normalizing RAI, affirming pleasure from RAI and acknowledging that the gastrointestinal system is involved in sexual pleasure, sexual function and sexual health will help transform the scientific paradigm of sexual health to one that is more just and equitable.

The elusive concept of sexual motivation: can it be anchored in the nervous system?

Sexual motivation is an abstract concept referring to the mechanisms determining the responsivity to sexually relevant stimuli. This responsivity determines the likelihood of producing a sexual response and the intensity of that response. Both responsivity to stimuli and the likelihood of making a response as well as the intensity of response are characteristics of an individual. Therefore, we need to assume that the concept of sexual motivation materializes in physiological mechanisms within the individual. The aim of the present communication is to analyze the requisites for the endeavor to materialize sexual motivation. The first requisite is to provide an operational definition, making the concept quantifiable. We show that parameters of copulatory behavior are inappropriate. We argue that the intensity of sexual approach behaviors provides the best estimate of sexual motivation in non-human animals, whereas the magnitude of genital responses is an exquisite indicator of human sexual motivation. Having assured how to quantify sexual motivation, we can then proceed to the search for physiological or neurobiological underpinnings. In fact, sexual motivation only manifests itself in animals exposed to appropriate amounts of gonadal hormones. In female rats, the estrogen receptor α in the ventrolateral part of the ventromedial nucleus of the hypothalamus is necessary for the expression of sexual approach behaviors. In male rats, androgen receptors within the medial preoptic area are crucial. Thus, in rats sexual motivation can be localized to specific brain structures, and even to specific cells within these structures. In humans, it is not even known if sexual motivation is materialized in the brain or in peripheral structures. Substantial efforts have been made to determine the relationship between the activity of neurotransmitters and the intensity of sexual motivation, particularly in rodents. The results of this effort have been meager. Likewise, efforts of finding drugs to stimulate sexual motivation, particularly in women complaining of low sexual desire, have produced dismal results. In sum, it appears that the abstract concept of sexual motivation can be reliably quantified, and the neurobiological bases can be described in non-human animals. In humans, objective quantification is feasible, but the neurobiological substrate remains enigmatic.

G-Spot Anatomy and its Clinical Significance: A Systematic Review

The discovery of the G-spot and verification of its anatomy and histology paved the way to better understanding. Until 2012, the G-spot was defined as a physiological sexual response phenomenon with no identifiable anatomical correlate. The weakness of this definition is that a physiological response cannot exist without an anatomical basis, so the question motivating the present study was formulated: Are current scientific-clinical data sufficient to resolve the controversy about the anatomical existence of a G-spot? It is important to stipulate that no systematic review of the G-spot has hitherto been published. Manual and electronic searches revealed postmortem and in vivo studies describing the G-spot and findings reported within PRISMA-IPD guidelines. The objective of the present review was to provide evidence-based information related to the G-spot. Articles were quality-assessed using validated instruments. Publications on the G-spot from 1950 to May 2019 were reviewed. Of the 279 full-text articles examined, 30 met the eligibility criteria. The findings indicate that there are reliable scientific-clinical data to support the existence of an anatomical G-spot structure. Transient anterior-distal vaginal wall engorgement is caused by blood entrapment within the G-spot structure. Histological examination effectively ruled out the G-spot as the organ cannot be responsible for female ejaculation since no glandular tissue was identifiable. Finally, the results of this study could assist in developing new therapeutic, surgical interventions to treat secondary G-spot dysfunction. Additionally, this review indicates ample opportunities for further scientific-clinical investigations and has thereby moved the field forward. Clin. Anat. 32:1094-1101, 2019. © 2019 Wiley Periodicals, Inc.

The neuroendocrinology of sexual attraction

Sexual attraction has two components: Emission of sexually attractive stimuli and responsiveness to these stimuli. In rodents, olfactory stimuli are necessary but not sufficient for attraction. We argue that body odors are far superior to odors from excreta (urine, feces) as sexual attractants. Body odors are produced by sebaceous glands all over the body surface and in specialized glands. In primates, visual stimuli, for example the sexual skin, are more important than olfactory. The role of gonadal hormones for the production of and responsiveness to odorants is well established. Both the androgen and the estrogen receptor α are important in male as well as in female rodents. Also in primates, gonadal hormones are necessary for the responsiveness to sexual attractants. In males, the androgen receptor is sufficient for sustaining responsiveness. In female non-human primates, estrogens are needed, whereas androgens seem to contribute to responsiveness in women.

Influence of PDE5 inhibitor on MRI measurement of clitoral volume response in women with FSAD: a feasibility study of a potential technique for evaluating drug response

The purpose of this study was to determine if magnetic resonance imaging (MRI) could quantify a difference in clitoral response following administration of a vasoactive medication, in 12 women with female sexual arousal disorder (FSAD). Subjects were entered into a double-blind, randomized two-way crossover study of sildenafil 50 mg vs placebo administered 1 h prior to genital MRI. Each subject underwent two MR studies, performed while subjects viewed alternating segments of nonerotic and erotic video. MR images were analyzed for change in clitoral volume during each session. The mean change in clitoral volume for the entire group was higher in the sildenafil MRI session (1282 mm(3)) compared with placebo (849 mm(3)) but did not reach statistical significance (P=0.064). Comparison using analysis of variance between the two sessions for each individual subject revealed a significant increase in clitoral volume following sildenafil compared with placebo in 6 of 12 subjects, no significant change in either imaging session in three subjects and in three subjects, there was a robust clitoral response in both MR sessions. In conclusion, MR measurements of clitoral volume can provide an objective measure of engorgement change following a vasoactive medication in women with FSAD.

Hormones and sexuality: Current complexities and future directions

Complex correlations between women's sexual function and psychosexual variables confound the identification of any etiological role for estrogen and androgen deficiencies in sexual dysfunction. Although serum levels of androgens show minimal correlation with women's sexual function, the intracellular production of testosterone from adrenal and ovarian precursors may be relevant. Current research involves the detailed assessment of mid aged and older women, with and without sexual dysfunction, assessing medical and multiple psychosexual parameters, estrogen status, serum testosterone levels by mass spectrometry methods plus total androgen activity by means of androgen metabolites. Identification of any correlation between androgen activity and sexual function is one priority. A second is to confirm safety and efficacy of supplemental systemic estrogen and androgen from early menopause in sexually symptomatic women. Although local estrogen supplementation is effective therapy for loss of genital sexual sensitivity and vaginal elasticity, and reduced potential for lubrication, any systemic testosterone therapy requires concomitant systemic estrogen therapy. In the future, augmentation of estrogen and androgen sexual effects may be possible using certain selective estrogen and androgen receptor modulators.

Sexual sequelae of general medical disorders

That sexual symptoms can signal serious underlying disease confirms the importance of sexual enquiry as an integral component of medical assessment. Data on sexual function are sparse in some medical specialties. However, increased scientific understanding of the central and peripheral physiology of sexual response could help to identify the pathophysiology of sexual dysfunction from disease and medical interventions, and also to ameliorate or prevent some dysfunctions. Many common general medical disorders have negative effects on desire, arousal, orgasm, ejaculation, and freedom from pain during sex. Chronic disease also interferes indirectly with sexual function, by altering relationships and self-image and causing fatigue, pain, disfigurement, and dependency. Current approaches to assessment of sexual dysfunction are based on models that combine psychological and biological aspects.

Clitoral anatomy in nulliparous, healthy, premenopausal volunteers using unenhanced magnetic resonance imaging

PURPOSE

We determined the magnetic resonance imaging (MRI) characteristics of normal clitoral anatomy.

MATERIALS AND METHODS

A series of MRI studies of 10 healthy, nulliparous volunteers with no prior surgery and normal pelvic examination was studied and the key characteristics of clitoral anatomy were determined. A range of different magnetic resonance sequences was used without any contrast agent.

RESULTS

The axial plane best revealed the clitoral body and its proximal continuation as the paired crura. The glans was seen more caudal than the body of the clitoris. The bulbs of the clitoris had the same signal as the rest of the clitoris in the axial plane and they related consistently to the other erectile structures. The bulbs, body and crura formed an erectile tissue cluster, namely the clitoris. In turn, the clitoris partially surrounded the urethra and vagina, forming a consistently observed tissue complex. Midline sagittal section revealed the shape of the body, although in this plane the rest of the clitoris was poorly displayed. The coronal plane revealed the relationship between the clitoral body and labia. The axial section cephalad to the clitoral body best revealed the vascular component of the neurovascular bundle to the clitoris. The fat saturation sequence particularly highlighted clitoral anatomy in healthy, premenopausal, nulliparous women.

CONCLUSIONS

Normal clitoral anatomy has been clearly demonstrated using noncontrast pelvic MRI.

Evaluation of the role of pudendal nerve integrity in female sexual function using noninvasive techniques

OBJECTIVE

Using quantitative sensory testing and a validated questionnaire, we investigated the role of pudendal nerve integrity in sexual function among women.

STUDY DESIGN

Participants completed the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ). Vibratory and pressure thresholds were measured at the S2 dermatome reflecting pudendal nerve distribution.

RESULTS

A total of 56 women enrolled; 29 (51.8%) were asymptomatic and 27 (48.2%) had 1 or more forms of female sexual dysfunction (total sexual dysfunction) including: desire disorder 16.1%, arousal disorder 26.8%, orgasmic disorder 25%, and pain disorder 12.5%. Age, parity, menopausal status, and body mass index were similar between groups. PISQ scores were lower in symptomatic subjects compared with controls (P < .001). Decreased tactile sensation was found at the clitoris for women with total sexual dysfunction, desire disorder, and arousal disorder. Women with arousal disorder also had decreased tactile sensation at the perineum.

CONCLUSION

Pudendal nerve integrity may play a role in female sexual dysfunction.

Genital vascular responsiveness and sexual feelings in midlife women: psychophysiologic, brain, and genital imaging studies

The incidence of women's experiences of lack of sexual arousal increases in the years around the natural menopause transition. This raises the questions to what extent are sexual complaints in postmenopausal women related to hormonal changes, and what is the contribution of psychologic and contextual factors to sexual function in this transitional phase of life. This article reviews all published evidence regarding (1) the relation between menopausal status and sexual arousal symptoms, (2) the extent to which these sexual symptoms relate to measured genital vascular responses to sexual stimuli, and (3) the correlation between women's genital vascular response and their experience of subjective sexual arousal. Psychophysiologic and preliminary functional magnetic resonance imaging (MRI) studies of increases in genital congestion in response to erotic stimulation fail to identify differences between premenopausal and postmenopausal women. This suggests that although urogenital aging results in changes in anatomy and physiology of the genitals, postmenopausal women preserve their genital responsivity when sufficiently sexually stimulated. The vaginal dryness and dyspareunia experienced by some postmenopausal women may result from longstanding lack of sexual arousal and protection from pain previously afforded by estrogen-related relatively high blood flow in the unaroused state. Psychophysiologic studies confirm similar increases in genital vasocongestion from erotic stimuli in women with and without chronically low sexual arousal, even in those women focusing specifically on their perceived lack of genital response. Moreover, studies repeatedly confirm highly variable correlations between subjective sexual arousal and measured increases in genital congestion.