Neural correlates of painful genital touch in women with vulvar vestibulitis syndrome

The relationship between fibromyalgia and pressure pain threshold in patients with dyspareunia

OBJECTIVE

To evaluate the number of tender points, pressure pain threshold and presence of fibromyalgia among women with or without dyspareunia.

METHODS

The present cross-sectional study included 40 patients with dyspareunia and 30 healthy controls. The participants were asked if they had engaged in sexual intercourse during the previous four weeks, and dyspareunia was rated from 0 to 3 based on the Marinoff Dyspareunia Scale. A pressure algometer (dolorimeter) was used to measure the pressure pain threshold. Fibromyalgia was diagnosed based on the 1990 American College of Rheumatology criteria. The depression status of the participants was assessed using the Beck Depression Inventory.

RESULTS

No statistically significant difference was found with regard to age, body mass index, habits (alcohol use and smoking), educational status and occupational status between the two groups. Total myalgic score, total control score and tender point mean pain threshold were significantly lower in the group with dyspareunia. The number of tender points was significantly higher in patients with dyspareunia. The mean Beck Depression Inventory score was 14.7±8.4 in the dyspareunia group compared with 11.2±7.1 in the control group. Five (12.5%) of the patients with dyspareunia were diagnosed with fibromyalgia, whereas no patients in the control group were diagnosed with fibromyalgia. There was no significant difference between the two groups with regard to the presence of fibromyalgia.

CONCLUSION

The finding of lower pressure pain thresholds and a higher number of tender points among patients with dyspareunia suggests that these patients may have increased generalized pain thresholds. Additional studies involving a larger number of patients are required to investigate the presence of central mechanisms in the pathogenesis of dyspareunia.

Bladder Distension Increases Blood Flow in Pain Related Brain Structures in Subjects with Interstitial Cystitis

PURPOSE

In healthy control subjects certain brain regions of interest demonstrate increased regional cerebral blood flow in response to painful stimuli. We examined the effect of bladder distension on arterial spin label functional magnetic resonance imaging measures of regional cerebral blood flow in regions of interest in subjects with interstitial cystitis.

MATERIALS AND METHODS

A total of 11 female subjects with interstitial cystitis and 11 healthy controls underwent 3 brain perfusion scan studies using arterial spin label functional magnetic resonance imaging, including 1) with a full bladder, 2) with an empty bladder and 3) while experiencing heat pain. Regional cerebral blood flow was calculated using custom software and individual scans were spatially normalized to the MNI (Montreal Neurological Institute) template. Region of interest based, absolute regional cerebral blood flow was determined for each condition and for the within group/within subject regional cerebral blood flow distribution changes induced by each condition.

RESULTS

Bladder distension was associated with robust increases in regional cerebral blood flow in subjects with interstitial cystitis. The increases were greater than those in healthy controls in multiple regions of interest, including the supplemental motor area (mainly Brodmann area 6), the motor and sensory cortex, the insula bilaterally, the hippocampal structures bilaterally, and the middle and posterior cingulate areas bilaterally. During heat pain healthy controls had more robust regional cerebral blood flow increases in the amygdala bilaterally. At baseline with an empty bladder there was lower regional cerebral blood flow in the insula, and the mid and posterior cingulate cortex bilaterally in subjects with interstitial cystitis.

CONCLUSIONS

Compared to healthy controls, subjects with interstitial cystitis have limited differences in regional cerebral blood flow in baseline (empty bladder) conditions as well as during heat pain. However, they had robust regional cerebral blood flow increases in the full bladder state in regions of interest typically associated with pain, emotion and/or motor control, indicating altered processing of bladder related sensations.

Similarities between interstitial cystitis/bladder pain syndrome and vulvodynia: implications for patient management

Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies.

Disease-related differences in resting-state networks: a comparison between localized provoked vulvodynia, irritable bowel syndrome, and healthy control subjects

Localized provoked vulvodynia (LPVD) affects approximately 16% of the female population, but biological mechanisms underlying symptoms remain unknown. Like in other often comorbid chronic pain disorders, altered sensory processing and modulation of pain, including central sensitization, dysregulation of endogenous pain modulatory systems, and attentional enhancement of pain perception, have been implicated. The aim of this study was to test whether regions of interest showing differences in LPVD compared to healthy control subjects (HCs) in structural and evoked-pain neuroimaging studies, also show alterations during rest when compared with HCs and a chronic pain control group (irritable bowel syndrome [IBS]). Functional magnetic resonance imaging was performed during resting state in 87 age-matched premenopausal females (29 LPVD, 29 HCs, and 29 IBS). Group-independent component analysis and general linear models were applied to investigate group differences in the intrinsic connectivity of regions comprising sensorimotor, salience, and default mode resting-state networks. Subjects with LPVD showed substantial alterations in the intrinsic connectivity of these networks compared with HCs and IBS. The intrinsic connectivity of many of the regions showing group differences during rest were moderately associated with clinical symptom reports in LPVD. Findings were robust to controlling for affect and medication usage. The current findings indicate that subjects with LPVD have alterations in the intrinsic connectivity of regions comprising the sensorimotor, salience, and default mode networks. Although shared brain mechanisms between different chronic pain disorders have been postulated, the current findings suggest that some alterations in functional connectivity may show disease specificity.

Vulvar vestibulodynia: strategies to meet the challenge

Vulvodynia is a condition that affects approximately 8% to 12% of women during their lifetimes. Vulvar vestibulodynia (VVD), the most common form of this condition, is characterized by pain with touch at the vulvar vestibule and resulting entryway dyspareunia. Studies suggest a multifactorial etiology; hormonal effects, muscle dysfunction, personality, psychosocial factors, and inflammatory mediators may all play some role in the development of this condition. Both peripheral and central sensitization to pain have been implicated in the development of enhanced pain experienced by women with VVD. Recommendations for the treatment of this condition exist; however, treatments of this condition have not been well studied. Few prospective placebo-controlled trials exist, and many of those that do have failed to show clinically relevant efficacy associated with traditional therapies. New studies into the etiology of this condition, as well as potential new therapies, are emerging, but the optimal approach has yet to be defined. Proper vulvar hygiene is recommended, and traditional therapies such as topical medications and centrally acting oral medications may continue to play a role in treatment. Newer studies elucidating the effects of personality and cognitive factors as well as pelvic floor muscle dysfunction in the development of this condition lend support for the inclusion of cognitive behavioral therapy and physical therapy/surface electromyographic biofeedback in the treatment regimen. Surgery for this condition exists, with success rates of 60% to 90%; however, it is recommended only in cases that have failed to respond to traditional therapy.

Reliability and Convergent Validity of the Algometer for Vestibular Pain Assessment in Women with Provoked Vestibulodynia

OBJECTIVE

Women with provoked vestibulodynia (PVD) suffer pain at the entry of the vagina elicited by pressure as during vaginal penetration. To quantify vestibular pain, we developed a new instrument, an algometer. The aim of this study was to investigate the test-retest reliability of the algometer and evaluate its convergent validity for vestibular pain assessment in women with PVD.

METHODS

Twenty-six women with PVD participated in the study. Vestibular pain was assessed with the new algometer and the already known vulvalgesiometer during two different sessions 2 to 4 weeks apart. At each session, the pressure pain threshold (PPT) and pressure pain tolerance (PPTol) were measured twice at the 3, 6, and 9 o'clock sites of the vestibule in random order. The test-retest reliability (intra- and inter-session) of the algometer was calculated using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Its convergent validity was evaluated by the correlation coefficients between PPTs and PPTols measured by the algometer and those measured with the vulvalgesiometer.

RESULTS

Intra-session reliability at all three sites for PPTs and PPTols in both sessions was excellent (ICC = 0.859 to 0.988, P ≤ 0.002). Inter-session reliability was good to excellent (ICC = 0.683 to 0.922, SEM = 15.06 to 47.04 g, P ≤ 0.001). Significant correlations were found between the two tools for all sites for PPTs (r = 0.500 to 0.614, P ≤ 0.009) and PPTols (r = 0.809 to 0.842, P < 0.001).

DISCUSSION

Findings showed that the algometer is a reliable and valid instrument for measuring PPTs and PPTols in the vestibular area in women with PVD. This technology is promising for pinpointing treatment mechanisms and efficacy.

Chronic Pelvic and Vulvar Pain in Women

Peripheral generators and the central nervous system have a role in the production of visceral and somatic hypersensivities and hyperalgesias.More generalised symptoms often exist and efferent activity from the CNS may also be responsible for abnormal visceral and muscular function.It is important to dissect out the symptoms and as well as treating peripheral generators to consider interventions of the central mechanisms aimed at the cognitive behavioural aspects of the patients' condition.

Neuroimaging of Visceral Pain

Functional neuroimaging allows conscious reporting by human subjects to be related to changes in brain activation during painful stimulation.Brain regions thought to be involved in the perception of pain include the primary and secondary somatosensory cortex, the anterior cingulate cortex, the prefrontal cortex, the insula and the thalamus.There are major similarities in how visceral pain and somatic pain are processed by the brain.No single brain region has been found to be responsible for visceral pain.Patients with IBS often activate the same brain regions as healthy controls in response to pain, but with differing intensities.Functional neuroimaging studies have failed to reach a consensus opinion on how the brain processes pain in Irritable Bowel Syndrome.

The cortical sensory representation of genitalia in women and men: a systematic review

Background

Although genital sensations are an essential aspect of sexual behavior, the cortical somatosensory representation of genitalia in women and men remain poorly known and contradictory results have been reported.

Objective

To conduct a systematic review of studies based on electrophysiological and functional neuroimaging studies, with the aim to identify insights brought by modern methods since the early descriptions of the sensory homunculus in the primary somatosensory cortex (SI).

Results

The review supports the interpretation that there are two distinct representations of genital sensations in SI, one on the medial surface and the other on the lateral surface. In addition, the review suggests that the secondary somatosensory cortex and the posterior insula support a representation of the affective aspects of genital sensation.

Conclusion

In view of the erogenous character of sensations originating in the genitalia, future studies on this topic should systematically assess qualitatively as well as quantitatively the sexually stimulating and/or sexually pleasurable characteristics of sensations felt by subjects in response to experimental stimuli.

Central changes associated with chronic pelvic pain and endometriosis

BACKGROUND

Chronic pelvic pain (CPP) is a significant public health problem with 1 million affected women in the UK. Although many pathologies are associated with CPP, the pain experienced is often disproportionate to the extent of disease identified and frequently no pathology is found (chronic pelvic pain syndrome). The central nervous system (CNS) is central to the experience of pain and chronic pain conditions in general are associated with alterations in both the structure and function of the CNS. This review describes the available evidence for central changes in association with conditions presenting with CPP.

METHODS

A detailed literature search was performed to identify relevant papers, however, this is not a systematic review.

RESULTS

CPP is associated with central changes similar to those identified in other pain conditions. Specifically these include, alterations in the behavioural and central response to noxious stimulation, changes in brain structure (both increases and decreases in the volume of specific brain regions), altered activity of both the hypothalamic-pituitary-adrenal axis and the autonomic nervous system (ANS) and psychological distress.

CONCLUSIONS

The evidence reviewed in this paper demonstrates that CPP is associated with significant central changes when compared with healthy pain-free women. Moreover, the presence of these changes has the potential to both exacerbate symptoms and to predispose these women to the development of additional chronic conditions. These findings support the use of adjunctive medication targeting the CNS in these women.

Rationale and design of a multicenter randomized clinical trial of extended release gabapentin in provoked vestibulodynia and biological correlates of response

INTRODUCTION

Few randomized controlled trials (RCTs) have been conducted to establish evidence-based management protocols for provoked vestibulodynia (PVD), a chronic vulvar pain condition affecting approximately 14 million women in the U.S. We describe the rationale and design of an NIH funded multicenter clinical trial utilizing an extended release formulation of gabapentin (G-ER), an intervention that preliminary data suggest may be efficacious for this condition.

OBJECTIVES

1) to determine if pain from tampon insertion (primary outcome measure) is lower in PVD patients when treated with G-ER compared to when treated with placebo and 2) to determine if G-ER reduces vulvar mechanical hyperalgesia, vaginal muscle pain to palpation, the number and intensity of somatic tenderpoints, spontaneous and provoked pain to intradermal capsaicin with an accompanying increase in cardiac beat-to-beat variability and to identify mechanistically-based PVD subtypes. Additional outcomes include subject reported intercourse pain and summative 24-hour pain.

METHODS

This 16-week, randomized, double-blind, placebo-controlled, crossover study will enroll 120 women 18 years and older who report tenderness localized to the vulvar vestibule, pain with tampon insertion, and, when sexually active, insertional dyspareunia. Electronically entered daily diaries will be used to determine if pain is lower in PVD subjects when treated with G-ER (up to 3000 mg/d) compared to when treated with placebo. Psychophysiological measures will be obtained at baseline and after 2 weeks at the maximum tolerated dose.

CONCLUSION

We will conduct the first multicenter RCT to confirm efficacy of an agent that is currently used in clinical practice for treating PVD.

Cognitive and emotional control of pain and its disruption in chronic pain

Chronic pain is one of the most prevalent health problems in our modern world, with millions of people debilitated by conditions such as back pain, headache and arthritis. To address this growing problem, many people are turning to mind-body therapies, including meditation, yoga and cognitive behavioural therapy. This article will review the neural mechanisms underlying the modulation of pain by cognitive and emotional states - important components of mind-body therapies. It will also examine the accumulating evidence that chronic pain itself alters brain circuitry, including that involved in endogenous pain control, suggesting that controlling pain becomes increasingly difficult as pain becomes chronic.

Latent class analysis of comorbidity patterns among women with generalized and localized vulvodynia: preliminary findings

BACKGROUND

The pattern and extent of clustering of comorbid pain conditions with vulvodynia is largely unknown. However, elucidating such patterns may improve our understanding of the underlying mechanisms involved in these common causes of chronic pain. We sought to describe the pattern of comorbid pain clustering in a population-based sample of women with diagnosed vulvodynia.

METHODS

A total of 1457 women with diagnosed vulvodynia self-reported their type of vulvar pain as localized, generalized, or both. Respondents were also surveyed about the presence of comorbid pain conditions, including temporomandibular joint and muscle disorders, interstitial cystitis, fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, endometriosis, and chronic headache. Age-adjusted latent class analysis modeled extant patterns of comorbidity by vulvar pain type, and a multigroup model was used to test for the equality of comorbidity patterns using a comparison of prevalence. A two-class model (no/single comorbidity versus multiple comorbidities) had the best fit in individual and multigroup models.

RESULTS

For the no/single comorbidity class, the posterior probability prevalence of item endorsement ranged from 0.9% to 24.4%, indicating a low probability of presence. Conversely, the multiple comorbidity class showed that at least two comorbid conditions were likely to be endorsed by at least 50% of women in that class, and irritable bowel syndrome and fibromyalgia were the most common comorbidities regardless of type of vulvar pain. Prevalence of the multiple comorbidity class differed by type of vulvar pain: both (37.6% prevalence, referent), generalized (21.6% prevalence, adjusted odds ratio 0.41, 95% confidence interval 0.27-0.61), or localized (12.5% prevalence, adjusted odds ratio 0.31, 95% confidence interval 0.21-0.47).

CONCLUSION

This novel work provides insight into potential shared mechanisms of vulvodynia by describing that a prominent comorbidity pattern involves having both irritable bowel syndrome and fibromyalgia. In addition, the prevalence of a multiple comorbidity class pattern increases with increasing severity of vulvar pain.

Augmented central pain processing in vulvodynia

Vulvodynia (VVD) is a chronic pain disorder wherein women display sensitivity to evoked stimuli at the vulva and/or spontaneous vulvar pain. Our previous work suggests generalized hyperalgesia in this population; however, little is known about central neurobiological factors that may influence pain in VVD. Here we investigated local (vulvar) and remote (thumb) pressure-evoked pain processing in 24 VVD patients compared to 13 age-matched, pain-free healthy controls (HCs). As a positive control we also examined thumb pressure pain in 24 fibromyalgia patients. The VVD and fibromyalgia patients displayed overlapping insular brain activations that were greater than HCs in response to thumb stimulation (P < .005 corrected). Compared to HCs, VVD participants displayed greater levels of activation during thumb stimulation within the insula, dorsal midcingulate, posterior cingulate, and thalamus (P < .005 corrected). Significant differences between VVD subgroups (primary versus secondary and provoked versus unprovoked) were seen within the posterior cingulate with thumb stimulation and within the precuneus region with vulvar stimulation (provoked versus unprovoked only). The augmented brain activation in VVD patients in response to a stimulus remote from the vulva suggests central neural pathology in this disorder. Moreover, differing central activity between VVD subgroups suggests heterogeneous pathologies within this diagnosis.

PERSPECTIVE

The presence of augmented brain responses to pressure stimuli remote from the vulva was observed in vulvodynia patients. These findings may guide treatment decisions for better response, as brain mechanisms may be a factor in some VVD patients.

Relationship between vulvodynia and chronic comorbid pain conditions

OBJECTIVE

To estimate the relationship among the presence of vulvodynia, fibromyalgia, interstitial cystitis, and irritable bowel syndrome.

METHODS

Validated questionnaire-based screening tests for the four pain conditions were completed by women with and without vulvodynia who were participating in the Michigan Woman to Woman Health Study, a longitudinal population-based survey in southeastern Michigan. Weighted population-based estimates of the prevalence and characteristics of participants with these chronic comorbid pain conditions were calculated using regression analyses.

RESULTS

Of 1,940 women who completed the survey containing all four screening tests, 1,890 (97.4%) answered all screening questions and were included. The prevalences of the screening-based diagnoses ranged from 7.5% (95% confidence interval [CI] 6.2-9.0) for interstitial cystitis, 8.7% (95% CI 7.3-10.4) for vulvodynia, 9.4% (95% CI 8.1-11.0) for irritable bowel syndrome, to 11.8% (95% CI 10.1-13.7) for fibromyalgia with 27.1% screening positive for multiple conditions. The presence of vulvodynia was associated with the presence of each of the other comorbid pain conditions (P<.001, odds ratio 2.3-3.3). Demographic risk factors for each condition varied. Increasing age was not associated with greater numbers of comorbid conditions, and only low socioeconomic status was associated with having multiple comorbid conditions concurrently.

CONCLUSION

Chronic pain conditions are common, and a subgroup of women with vulvodynia is more likely than those without vulvodynia to have one or more of the three other chronic pain conditions evaluated.

The human sexual response cycle: brain imaging evidence linking sex to other pleasures

Sexual behavior is critical to species survival, yet comparatively little is known about the neural mechanisms in the human brain. Here we systematically review the existing human brain imaging literature on sexual behavior and show that the functional neuroanatomy of sexual behavior is comparable to that involved in processing other rewarding stimuli. Sexual behavior clearly follows the established principles and phases for wanting, liking and satiety involved in the pleasure cycle of other rewards. The studies have uncovered the brain networks involved in sexual wanting or motivation/anticipation, as well as sexual liking or arousal/consummation, while there is very little data on sexual satiety or post-orgasmic refractory period. Human sexual behavior also interacts with other pleasures, most notably social interaction and high arousal states. We discuss the changes in the underlying brain networks supporting sexual behavior in the context of the pleasure cycle, the changes to this cycle over the individual's life-time and the interactions between them. Overall, it is clear from the data that the functional neuroanatomy of sex is very similar to that of other pleasures and that it is unlikely that there is anything special about the brain mechanisms and networks underlying sex.

Doing it … wild? On the role of the cerebral cortex in human sexual activity

BACKGROUND

We like to think about sexual activity as something fixed, basic and primal. However, this does not seem to fully capture reality. Even when we relish sex, we may be capable of mentalizing, talking, voluntarily postponing orgasm, and much more. This might indicate that the central control mechanisms of sexual activity are quite flexible and susceptible to learning mechanisms, and that cortical brain areas play a critical part.

OBJECTIVE

This study aimed to identify those cortical areas and mechanisms most consistently implicated in sexual activity.

DESIGN

A comprehensive review of the human functional neuroimaging literature on sexual activity, i.e. genital stimulation and orgasm, is made.

RESULTS

Genital stimulation recruits the classical somatosensory matrix, but also areas far beyond that. The posterior insula may be particularly important for processing input from the engorged penis and coordinating penile responses. Extrastriate visual cortex tracks sexual arousal and responds to genital stimulation even when subjects have their eyes closed. The ventromedial prefrontal cortex is also tightly coupled to sexual arousal, but low activity in this area predicts high sexual arousal.

CONCLUSION

This review has indicated cortical sites where activity is moderated by tactile genital inflow and high sexual arousal. Behavioral implications are discussed and where possible the relevance for learning mechanisms is indicated. Overall, it is clear that the cerebral cortex has something to say about sexual activity.

Altered central sensitization in subgroups of women with vulvodynia

OBJECTIVE

To investigate the clinical correlates of central nervous system alterations among women with vulvodynia. Altered central sensitization has been linked to dysfunction in central nervous system-inhibitory pathways (e.g., γ-aminobutyric acidergic), and metrics of sensory adaptation, a centrally mediated process that is sensitive to this dysfunction, could potentially be used to identify women at risk of treatment failure using conventional approaches.

METHODS

Twelve women with vulvodynia and 20 age-matched controls participated in this study, which was conducted by sensory testing of the right hand's index and middle fingers. The following sensory precepts were assessed: (1) vibrotactile detection threshold; (2) amplitude discrimination capacity (defined as the ability to detect differences in intensity of simultaneously delivered stimuli to 2 fingers); and (3) a metric of adaptation (determined by the impact that applying conditioning stimuli have on amplitude discriminative capacity).

RESULTS

Participants did not differ on key demographic variables, vibrotactile detection threshold, and amplitude discrimination capacity. However, we found significant differences from controls in adaptation metrics in 1 subgroup of vulvodynia patients. Compared with healthy controls and women with a shorter history of pain [n=5; duration (y) = 3.4 ± 1.3], those with a longer history [n=7; duration (y) = 9.3 ± 1.4)] were found to be less likely to have adaptation metrics similar to control values.

DISCUSSION

Chronic pain is thought to lead to altered central sensitization, and adaptation is a centrally mediated process that is sensitive to this condition. This report suggests that similar alterations exist in a subgroup of vulvodynia patients.

Repeated vulvovaginal fungal infections cause persistent pain in a mouse model of vulvodynia

Provoked vestibulodynia, the most common form of vulvodynia (unexplained pain of the vulva), is a prevalent, idiopathic pain disorder associated with a history of recurrent candidiasis (yeast infections). It is characterized by vulvar allodynia (painful hypersensitivity to touch) and hyperinnervation. We tested whether repeated, localized exposure of the vulva to a common fungal pathogen can lead to the development of chronic pain. A subset of female mice subjected to recurrent Candida albicans infection developed mechanical allodynia localized to the vulva. The mice with allodynia also exhibited hyperinnervation with peptidergic nociceptor and sympathetic fibers (as indicated by increased protein gene product 9.5, calcitonin gene-related peptide, and vesicular monoamine transporter 2 immunoreactivity in the vaginal epithelium). Long-lasting behavioral allodynia in a subset of mice was also observed after a single, extended Candida infection, as well as after repeated vulvar (but not hind paw) inflammation induced with zymosan, a mixture of fungal antigens. The hypersensitivity and hyperinnervation were both present at least 3 weeks after the resolution of infection and inflammation. Our data show that infection can cause persistent pain long after its resolution and that recurrent yeast infection replicates important features of human provoked vulvodynia in the mouse.

Characteristics of response to experimental pain in sexually abused women

OBJECTIVES

Women with a history of sexual abuse (SA) commonly report greater pain symptoms. It is still unclear whether enhanced pain susceptibility is the result of altered pain processing and response. Therefore, this pilot study aimed to explore pain sensitivity to experimentally induced pain and associated psychology in women with a history of severe SA.

METHODS

Twenty-one survivors of severe, long-lasting SA and 21 control women underwent experimentally induced heat pain and completed psychological questionnaires. Pain measures included heat pain thresholds, pain intensity ratings, and pain tolerance in response to contact heat, painful stimulation delivered to the volar forearm. Questionnaires included somatization (Brief Symptom Inventory), personality traits including harm avoidance, novelty seeking, and reward dependence (Cloninger tridimensional personality questionnaire), and levels of dissociation (Dissociative Experiences Scale).

RESULTS

SA women had elevated heat pain thresholds (45.7±2.2°C vs. 43.9±3.1°C; P=0.042) and higher pain intensity ratings (on a 0 to 100 scale: 80.0±26.6 vs. 51.2±27.7; P=0.001). In addition, they had lower tolerability to painful tonic stimulation, greater somatization, and larger harm avoidance scores. Regression analyses showed that higher pain intensity ratings in SA women associated with greater tendency for harm avoidance but not with levels of dissociation.

DISCUSSION

Women with a history of severe SA seem to have a paradoxical pattern of experimental pain response, characterized by both higher pain thresholds and increased pain intensity ratings. This pattern is associated with the personality trait of harm avoidance. Models that might account for these findings are discussed.

Pelvic pain in women: clinical and scientific aspects

PURPOSE OF REVIEW

Pelvic pain is a common complaint of women that is frequently poorly managed. This review considers the current understanding of the mechanisms of pain perception and the development of chronic pain in the context of three gynaecological pain conditions. Recent advances in the management of these conditions are then discussed.

RECENT FINDINGS

Persistent pelvic pain is associated with central changes, reflected by alterations in psychology, brain structure and function, and dysfunction of the hypothalamic-pituitary-adrenal axis. The many similarities among the conditions support the notion that chronic pain should be treated as a symptom in its own right, however, obtaining a diagnosis remains important to patients. Few new treatments have been developed recently, however, older treatments are being subjected to more rigorous testing and improvements in phenotyping should lead to better design of clinical trials.

SUMMARY

Good quality, well designed clinical trials are urgently required to improve the treatment of pelvic pain in women. However, a variety of successful treatments exist and outcomes can be optimized by individualizing treatment strategies in the context of a multidisciplinary package.

Males and females show differential brain activation to taste when hungry and sated in gustatory and reward areas

Although males and females differ in eating behavior and prevalence rates for eating disorders and obesity, little is known about gender differences in cortical activation to pleasant and unpleasant pure tastes during the physiological states of hunger and satiety. Twenty-one healthy young adults (12 females and 9 males) underwent two functional magnetic resonance imaging scans. Using four pure tastants of differing qualities (i.e., salty, sour, bitter, sweet), the present study examined gender differences in fMRI activation during two motivational states (hunger and satiety). There was greater change in fMRI activation from hunger to satiety in males than females in response to all tastes within the middle frontal gyrus (BA 10), insula, and cerebellum. Males also had greater change in activation from hunger to satiety, relative to females, in limbic regions including dorsal striatum, amygdala, parahippocampal gyrus, and posterior and anterior cingulate; however, activation was stimulus dependent, despite equivalent ratings in perceived pleasantness and intensity. Interestingly, males and females showed significant change from hunger to satiety in response to citric acid, suggesting that in addition to gender and physiological condition, stimulus quality is an important factor in taste fMRI activation. These gender differences may have implications for the pathophysiology of eating disorders and obesity.

Visual attention to erotic images in women reporting pain with intercourse

The coupling of sex and pain creates an interesting theoretical conundrum of clinical significance: Are women with dyspareunia distracted from sexual stimuli, or are they hypervigilant to sexual stimuli because these stimuli elicit thoughts and expectations of pain? This study measured attention to sexual stimuli in women reporting persistent pain with intercourse, women reporting low sexual desire, and women reporting no sexual problems. Participants viewed a series of erotic images, each containing an object intended to distract from the erotic scene regions, while an eye tracker recorded their eye movements. Women with pain looked for shorter periods of time and fewer times at the sexual scene region than did both women with low sexual desire (p = .024 and p = .018, respectively) and the no-dysfunction control group (p < .001 and p = .003, respectively). Women with pain also looked at the context (nonsexual) scene region significantly more times and for longer periods than did the no-dysfunction control women (p = .013 and p = .042, respectively). Results are interpreted to be potentially supportive of the cognitive distraction hypothesis associated with sexual dysfunction, with an additional component of cognitive avoidance of sexual stimuli for the women reporting sexual pain.

Pain imaging in health and disease--how far have we come?

Since modern brain imaging of pain began 20 years ago, networks in the brain related to pain processing and those related to different types of pain modulation, including placebo, have been identified. Functional and anatomical connectivity of these circuits has begun to be analyzed. Imaging in patients suggests that chronic pain is associated with altered function and structural abnormalities in pain modulatory circuits. Moreover, biochemical alterations associated with chronic pain are being identified that provide information on cellular correlates as well as potential mechanisms of structural changes. Data from these brain imaging studies reinforce the idea that chronic pain leads to brain changes that could have functional significance.

Pelvic floor muscle assessment outcomes in women with and without provoked vestibulodynia and the impact of a physical therapy program

INTRODUCTION

Physical therapy (PT) may reduce the pain associated with provoked vestibulodynia (PVD) based on previous findings that pelvic floor muscle dysfunction (PFMD) is associated with PVD symptoms.

AIMS

The goals of this study were: (i) to determine whether women with and without PVD differ on measures of pelvic floor muscle (PFM) behavior; and (ii) to assess the impact of PT treatment for women with PVD on these measures.

METHODS

Eleven women with PVD and 11 control women completed an assessment evaluating PFM behavior using surface electromyography (SEMG) recordings and a digital intravaginal assessment. Women with PVD repeated the assessment after they had undergone eight PT treatment sessions of manual therapy, biofeedback, electrical stimulation, dilator insertions, and home exercises.

MAIN OUTCOME MEASURES

Superficial and deep PFM SEMG tonic activity and phasic activity in response to a painful pressure stimulus, PFM digital assessment variables (tone, flexibility, relaxation capacity, and strength).

RESULTS

At pretreatment, women with PVD had higher tonic SEMG activity in their superficial PFMs compared with the control group, whereas no differences were found in the deep PFMs. Both groups demonstrated contractile responses to the painful pressure stimulus that were significantly higher in the superficial as compared with the deep PFMs, with the responses in the PVD group being higher than those in control women. Women with PVD had higher PFM tone, decreased PFM flexibility and lower PFM relaxation capacity compared with control women. Posttreatment improvements included less PFM responsiveness to pain, less PFM tone, improved vaginal flexibility, and improved PFM relaxation capacity, such that women with PVD no longer differed from controls on these measures.

CONCLUSION

Women with PVD demonstrated altered PFM behavior when compared with controls, providing empirical evidence of PFMD, especially at the superficial layer. A PT rehabilitation program specifically targeting PFMD normalized PFM behavior in women with PVD.

Current perspectives in vulvodynia

Vulvodynia, or chronic vulvar pain, is a common but poorly understood condition. Although its etiology is not well understood, it appears to be multifactorial. As such, treatment options are targeted to reduce singular symptoms in a piecemeal fashion. A number of randomized, controlled trials have been conducted and at least one paper on combination therapy has been published; however, further systematic research is needed in order to more fully inform clinical practice.

Blood oxygenation level dependent functional magnetic resonance imaging: current and potential uses in obstetrics and gynaecology

Blood-oxygenation-level-dependent functional magnetic resonance imaging is a noninvasive technique that has become increasingly popular in the neurosciences. It measures the proportion of oxygenated haemoglobin in specific areas of the brain, mirroring blood flow and therefore function. Here we review how the findings from functional studies impact on areas of gynaecological practice as diverse as chronic pain, continence, and premenstrual dysphoric disorder. Finally we review some of the more novel applications of the technique, such as imaging of pelvic floor function and the effects of hypoxia on the fetus.

Negative affect and somatically focused anxiety in young women reporting pain with intercourse

After a long history of privileging psychosexual etiological factors over pain and physiological processes, dyspareunia has enjoyed 1 decade of pointed research focused on the presenting problem of pain. Although it is generally acknowledged that certain affective and cognitive styles may play a role in an individual's experience of pain in general, investigations into these questions specifically as they pertain to pain that occurs during sex are relatively scarce. To add to this growing body of knowledge, 759 women aged 18 to 29 completed questionnaires about current sexual functioning, gynecologic history, expectations about intercourse, and various personality and health-related anxiety measures. One-hundred-one women (14% of the sample) reported pain during intercourse on at least 50% of attempts. This group of women significantly differed from 536 women reporting pain on less than 10% of intercourse attempts on personality constructs related to emotional and relational well-being (e.g., neuroticism, extraversion, agreeableness), as well as anxiety sensitivity, anxiety related to physical health concerns, and the amplification of somatosensory experiences. This affective and cognitive profile is consistent with previous studies that have found an attentional hypervigilance to health and pain-related information in women with dyspareunia, all of which could prove germane to cognitive-behavioral treatments targeting this disorder.