Intraepidermal nerve fiber density in vulvar lichen sclerosus and normal vulvar tissues

Lichen sclerosus (LS) is a chronic and inflammatory disease causing sensory symptoms such as itch and pain and affecting most frequently genital skin of women. Intraepidermal nerve fiber density (IENFD) was examined immunohistologically in 20 vulvar skin biopsies of patients affected by LS and in 20 control vulvar skin biopsies, in order to determine if these sensory sensations originate in changes in the epidermal innervation. Obtained results show fewer protein gene product 9.5 (PGP 9.5) positive intraepidermal nerve fibers (IENF) in LS tissues compared to controls (P = 0.004), while the number of calcitonin gene-related peptide (CGRP) positive IENF in LS was increased compared to normal vulvar tissue (P = 0.03). No differences in the number of vasoactive intestinal peptide (VIP) expressing IENF could be observed. To our best knowledge, this is the first study to describe intraepidermal nerve fiber density in vulvar LS. Significant differences in IENFD between LS and control skin samples, which have been found, point to the damage to the small nerve fibers in the disease process of LS, which may contribute to pathogenesis of LS sensory symptoms.

The Safe Labiaplasty: A Study of Nerve Density in Labia Minora and Its Implications

BACKGROUND

Surgical techniques to alleviate labia minora hypertrophy are gaining popularity. Due to the rapidly growing number of labiaplasties performed around the world, there is concern for the safety of these procedures with respect to maintaining sensitivity to the genitalia and/or implications for sexual arousal.

OBJECTIVES

An anatomic study aimed at identifying the nerve density distribution of the labia minora was performed to provide unique insight into performing labiaplasty while preserving sensation.

METHODS

Four fresh tissue cadaver labia minora were analyzed. Each labia minora was divided into 6 anatomic areas. The samples from each of the 6 anatomic locations were analyzed for presence of nerve bundles using both a routine hematoxylin and eosin (H&E) stain and a confirmatory immunohistochemical staining for S100 protein. Nerve density was analyzed under light microscopy, counted, and then expressed as percentage nerve density as well as number of bundles per square millimeter.

RESULTS

Upon gross analysis, the raw data reveal that labia minora have a heterogeneous population of sensory nerves. When looking at percent nerve density, the data do not reveal any statistical differences between the anatomic locations.

CONCLUSIONS

Most labiaplasty techniques can be performed safely and are unlikely to cause loss of sensation as the nerve density distribution in labia minora is heterogeneous.

Increased vanilloid receptor VR1 innervation in vulvodynia

Vulvodynia is characterised by painful burning sensation, allodynia and hyperalgesia in the region of the vulval vestibulus. While in many patients the cause of vulvodynia remains uncertain, we and others have previously shown increased intraepithelial and papillary innervation in vulvodynia. The vanilloid receptor VR1 (TRPV1) is expressed by nociceptors, and is triggered by capsaicin, noxious heat, protons, and chemicals produced during inflammation. In the present study we show increased papillary VR1 fibres by immunostaining and image analysis in vulvodynia tissues compared to controls (p<0.002). VR1 expression was found to be significantly increased when the percentage area immunostained was expressed as a ratio of VR1 to PGP 9.5, a pan-neuronal marker (P=0.01). VR1-positive fine epidermal fibres also appeared to be increased in vulvodynia tissues, by inspection. Fibres immunoreactive to the voltage-gated sodium channel SNS1/PN3 (Nav1.8), also expressed by nociceptors, were relatively scarce in both vulvodynia and control tissues. We hypothesize that increased expression of VR1 by nociceptors could mediate some of the symptoms in vulvodynia, for which systemic or topical specific VR1 antagonists may provide novel treatment.

Differences in primary compared with secondary vestibulodynia by immunohistochemistry

OBJECTIVE

To assess whether primary and secondary vestibulodynia represent different pathologic pathways.

METHODS

This was an analysis of archived vestibulectomy specimens from 88 premenopausal women with vestibulodynia (2002-2008). Patient records were reviewed to classify the type of vestibulodynia, duration of symptoms, and hormone status. Histologic sections were stained for hematoxylin and eosin to grade inflammation, S100 to highlight nerves, CD117 for mast cells, estrogen receptor α, and progesterone receptor. Differences between primary and secondary vestibulodynia were tested by t tests, chi-square analysis, and linear and logistic regression.

RESULTS

Primary vestibulodynia showed significant neural hypertrophy and hyperplasia (P=.02, adjusted odds ratio [OR] 3.01, 95% confidence interval [CI] 1.2-7.6) and increased progesterone receptor nuclear immunostaining (P=.004, adjusted OR 3.94, CI 1.6-9.9) compared with secondary vestibulodynia. Estrogen receptor α expression was also greater in primary vestibulodynia when symptom diagnosis was less than 5 years (P=.004, adjusted OR 5.53 CI 1.71-17.91).

CONCLUSION

Primary and secondary vestibulodynia have significantly different histologic features, suggesting that they may have separate mechanistic pathways. Clinically, this may mean the discovery of distinct conditions.

[Lesions of peripheral nerves in obstetrics and gynecology. A review]

Peripheral nerves in obstetrics and gynecology are damaged with moderate frequency. Mostly there are iatrogenic lesions, that most often develop during delivery, operations and also in course of smaller invasive procedures. In genitofemoral nerve lesions neuralgic pain in groin and vulva is the most striking symptom, in cutaneous femoris lateralis nerve damage there are unpleasant paresthesias of lateral thigh. In case of femoral or obturator nerve lesion a weakness of thigh muscles with difficulties of standing and walking is the most typical. In pudendal nerve damage the autonomic disturbances (incontinence of feaces and urine) and pain in perineum are in the foreground of the patient's complains. After a knowledgeable history taking and detailed clinical examination the next step of diagnostics are neurophysiological investigations (neurography and needle electomyography). In special cases there is racional to use imaging methods (ultrasonography, MRI, CT). In majority of these iatrogennic nerve lesions the conservative approach is successful (rehabilitation, medicaments against neuropathic pain) and only in a small proportion of patients the neurosurgeon consultation is necessary.

Vulvodynia

INTRODUCTION

Vulvodynia is increasingly recognized as a cause of sexual pain. Aim. The goal of this Continuing Medical Education article was to provide a comprehensive review of vulvodynia including terminology, possible etiologies, and offer treatment options.

METHODS

A Medline search was conducted using several terms related to and including the terms vulvodynia, vulvar vestibulitis, vestibulodynia, and pudendal neuralgia.

RESULTS

A thorough review of vulvodynia.

CONCLUSION

Vulvodynia most likely represents several disorders without an identifiable cause in many cases. The management of these patients requires a sensitive provider who can coordinate a multidisciplinary approach to their care. Despite the lack of large-scale, placebo-controlled trials, several new treatment options exist.

Sensory roles of neuronal cilia: cilia development, morphogenesis, and function in C. elegans

In the free-living nematode Caenorhabditis elegans, cilia are found on the dendritic endings of sensory neurons. C. elegans cilia are classified as 'primary' or 'sensory' according to the '9+0' axonemal ultrastructure (nine doublet outer microtubules with no central microtubule pair) and lack of motility, characteristics of '9+2' cilia. The C. elegans ciliated nervous system allows the animal to perceive environmental stimuli and make appropriate developmental, physiological, and behavioral decisions. In vertebrates, the biological significance of primary cilia had been largely neglected. Recent findings have placed primary/sensory cilia in the center of cellular signaling and developmental processes. Studies using genetic model organisms such as C. elegans identified the link between ciliary dysfunction and human ciliopathies. Future studies in the worm will address important basic questions regarding ciliary development, morphogenesis, specialization, and signaling functions.

[Applied microanatomic study of pudendal-thigh skin flap]

OBJECTIVE

To investigate the microanatomic basis of the pudendal-thigh flap and provide the anatomic basis for clinical application.

METHODS

Skin microdissection of the pudendal regions was performed on 11 adult cadavers (22 sides). Then, the clinical way was simulated to obtain the flaps, and the vessels and nerves contained in them were surveyed. After that, the tissues in the deep part were dissected, and the vessels and nerves were traced back to their origins. The notes were taken.

RESULTS

The blood supply to the pudenal regions was plentiful and constant. The initiation point of the superficial external pudendal artery was 2.14+ 0.23 mm in diameter; one branch of it was the inguinal branch and the other branch was the perineal branch. Their diameters were 1.38+0.34 mm and 1.21+0.24 mm. The initiation point of the posterior labial or scrotum arteries was 1.13+ 0.24 mm in diameter, and the lateral branch was 0. 67+0. 33 mm in diameter. The anterior cutaneous branch of the obturator artery was 1.68+ 0.11 mm in diameter. The position of all the blood vessels was relatively constant, especially the external pudendal artery and the lateral branch of the posterior scrotal artery. Many of the blood vessels passed through the areas of the pudendum and the thigh, anastomosed with each other. Three groups of the vascular net passed through the upper, middle and lower parts of the flap. Three main groups of the innervation were as the following: the ramus femoralis nervi genitofemoralis, the cutaneous branches of the ilioinguinal nerve, and the post-nerve of the scrotum or the labia vulvae.

CONCLUSION

The pudendal-thigh flap has an abundant blood supply, and its dissection is convenient with an easy incision; the donor site is covert. The pudendal-thigh skin flap has the following advantages for the sexual organ reconstruction: the skin flap can have a good sensation and a good shape, and the operative procedure is easy to perform.

Effects of sexual arousal on genital and non-genital sensation: a comparison of women with vulvar vestibulitis syndrome and healthy controls

The relationship between sexual arousal and sensory perception has been a topic largely neglected within the realm of human sexuality research. The present study assessed the influence of sexual arousal on genital and non-genital sensation in women. It also examined the theory that painful intercourse is associated with insufficient sexual arousal. A total of 20 healthy women and 20 women with Vulvar Vestibulitis Syndrome (VVS) underwent genital and non-genital sensory testing at baseline and in response to erotic and neutral stimulus films. Touch and pain thresholds were assessed at the vulvar vestibule, inside the labia minora, and on the volar surface of the forearm. Sexual arousal was assessed via the measurement of surface skin temperature changes of the labia minora using a labial thermistor clip. Participants also completed questionnaires pertaining to mood, pain, and sexual functioning. In response to the erotic stimulus, both groups evidenced a significant increase in physiological sexual arousal and vulvar sensitivity. Women with VVS reported a significantly lower desire to engage in intercourse after having viewed the erotic film and reported lower levels of desire and arousal on questionnaire measures. Women with VVS also exhibited significantly more genital and non-genital pain sensitivity than healthy women across all conditions, in addition to more catastrophizing, hypervigilance, and fear of pain. Contrary to some theories, these data suggest that women with VVS are not lacking in physiological sexual arousal, and that physiological sexual arousal may actually increase vulvar sensation. Lack of subjective sexual arousal, however, may yet be implicated in vulvar pain during intercourse.

ORIGINAL RESEARCH—SEXUAL PAIN DISORDERS: Effectiveness of Hypnosis for the Treatment of Vulvar Vestibulitis Syndrome: A Preliminary Investigation

INTRODUCTION

Vulvar vestibulitis syndrome (VVS) is a common cause of vulvar pain. Therapeutic options target different pain systems believed to be involved in its development and maintenance. Most treatments target the pain component with the assumption that sexual function will increase once the pain has decreased, yet this is not necessarily the case.

AIMS

Research has supported the effectiveness of hypnosis for many chronic pain disorders, and a case report demonstrated pain reduction and an increase in intercourse pleasure in a woman with VVS. This preliminary study examined the effectiveness of hypnosis on pain and psychosexual function in VVS. METHODS; Eight women suffering from VVS completed a hypnosis screening assessment, an interview, pain and psychosexual questionnaires, a gynecologic examination, vestibular pain threshold measurement, a psychosexual assessment, and six hypnotherapy sessions. The physical examinations, interview, and questionnaires were repeated at 1 and 6 months posttreatment.

MAIN OUTCOME MEASURES

These included pain ratings during the gynecologic examination, vestibular pain thresholds, scores on the McGill Pain Questionnaire and Pain Catastrophizing Scale, and responses to questions on intercourse-related and nonintercourse-related pain. Measures of psychosexual function included the Female Sexual Function Index, State-Trait Anxiety Scale, Beck Depression Inventory-II, and the Brief Symptom Inventory.

RESULTS

Results indicated significant decreases in gynecologic examination pain and in several measures assessing intercourse pain, and nonsignificant increases in threshold. Some indices of noncoital vulvar pain decreased. Overall sexual function, particularly sexual satisfaction, increased at posttreatment. There were no differences on any psychological measure. Participants reported satisfaction with the treatment and rated their VVS pain reduction as average.

CONCLUSIONS

Hypnotherapy appears to be a promising treatment for reducing intercourse pain and some aspects of noncoital vulvar pain, and for restoring sexual function in women with VVS. These results suggest that a large controlled trial should be considered.

Itch and burning pain in women with partial vaginismus with or without vulvar vestibulitis

Fifty-three women with partial vaginismus with or without vulvar vestibulitis and 27 asymptomatic women estimated sensations of burning pain and itch at 20 standardized moments during a standardized penetration situation, including vaginal muscle contractions. Forty-three women with partial vaginismus (81.1%) reported burning pain, 23 (43.4%) itch, and 22 (41.5%) both complaints, compared to 0% of the asymptomatic women. In 17 of 22 cases, burning pain preceded the appearance of itch and in four cases the two complaints coincided. The median time from the moment when burning pain started until itch appeared was 150 seconds.

UNC-6 expression by the vulval precursor cells of Caenorhabditis elegans is required for the complex axon guidance of the HSN neurons

Netrin is an evolutionarily conserved axon guidance molecule that has both axonal attraction and repulsion activities. In Caenorhabditis elegans, Netrin/UNC-6 is secreted by ventral cells, attracting some axons ventrally and repelling some axons, which extend dorsally. One axon guided by UNC-6 is that of the HSN neuron. The axon guidance process for HSN neurons is complex, consisting of ventral growth, dorsal growth, branching, second ventral growth, fasciculation with ventral nerve cords, and then anterior growth. The vulval precursor cells (VPC) and the PVP and PVQ neurons are required for the HSN axon guidance; however, the molecular mechanisms involved are completely unknown. In this study, we found that the VPC strongly expressed UNC-6 during HSN axon growth. Silencing of UNC-6 expression in only the VPC, using a novel tissue-specific RNAi technique, resulted in abnormal HSN axon guidance. The expression of Netrin/UNC-6 by only the VPC in unc-6 null mutants partially rescued the HSN ventral axon guidance. Furthermore, the expression of Netrin/UNC-6 by the VPC and the ventral nerve cord (VNC) in unc-6 null mutants restored the complex HSN axon guidance. These results suggest that UNC-6 expressed by the VPC and the VNC cooperatively regulates the complex HSN axon guidance.

Breeding status affects motoneuron number and muscle size in naked mole-rats: recruitment of perineal motoneurons?

Naked mole-rats live in large colonies and exhibit a strict reproductive hierarchy. Each colony has one breeding female and one to three breeding males; all other individuals are nonreproductive subordinates. Subordinates show a remarkable lack of sex differences in behavior and anatomy, but can become reproductive if removed from the colony. We recently reported that the striated perineal muscles and their innervating motoneurons, which are sexually dimorphic in all other mammals examined to date, are not dimorphic in subordinate naked mole-rats. Here we asked whether sexual differentiation of this neuromuscular system occurs when a subordinate becomes a breeder. The size and number of cells within Onuf's nucleus (homologue of the rat spinal nucleus of the bulbocavernosus) as well as perineal muscle volume were examined in subordinate and breeding naked mole-rats of both sexes. Sex differences in perineal motoneurons were not observed, regardless of social status. To our surprise, however, counts of motoneurons in Onuf's nucleus were increased approximately 30% in breeders of both sexes. This was accompanied by a reciprocal decrease in cells in Onuf's nucleus that were characterized by small soma size, and lacked a clear nucleus or nucleolus. Although not exhibiting typical motoneuron morphology, some of these small cells were positive for the motoneuron marker, SMI-32. The neuronal changes correlate with increased perineal muscle volumes in breeders. We propose that small, relatively undifferentiated cells are recruited to the pool of large Onuf's nucleus motoneurons when subordinate naked mole-rats become breeders.

Arousing Properties of the Vulvar Epithelium

PURPOSE

The initiation of genital tactile stimulation is regarded as a precursor to sexual arousal and perhaps in women it is the most easily recognized initiator of central nervous system arousal. Unfortunately little published material details the specific mechanisms preceding arousal, beginning at the epithelial level, which are the sensory precursors to arousal. Little is known about its cutaneous receptors, nerves and the other histochemical properties of this epithelial tissue that contribute to sexual arousal. Sexual sensitivity evaluations target female genital somatosensory pathways for cutaneous sensation by testing evoked potentials of nerves, hot/cold and vibratory sensory discrimination. The anatomical bases of these several sensibilities form a subject for future investigation. We reviewed the known influences and mechanisms responsible for the arousing properties of the epithelium in the female external genitalia as well neural pathways associated with sexual arousal originating from the vulvar epithelium.

MATERIALS AND METHODS

A comprehensive review was done of published, relevant clinical and histological material in human and nonhuman vertebrate studies.

RESULTS

Tactile stimulation of the vulvar epithelium initiates changes suggesting complex integrative mechanisms. Influences of skin temperature, hormonal environment, mechanical tissue compliance and inflammation as well as the large number of transmitters and neuropeptides involved in peripheral pathways serving female sexual arousal speak of a direct sensory role.

CONCLUSIONS

Genital epithelial cells may actively participate in sensory function to initiate sexual arousal by expressing receptors and releasing neurotransmitters in response to stimuli, resulting in epithelial-neuronal interactions.

Psychological factors associated with perception of experimental pain in vulvar vestibulitis syndrome

This study assessed the association between pain perception and psychological variables in women with vulvar vestibulitis syndrome (VVS) by comparing 28 VVS women with 50 healthy women. We assessed non genital systemic pain perception with quantitative sensory testing by administering experimental pain stimuli to the forearm. The VVS women demonstrated a lower pain threshold and a higher magnitude estimation of pain, combined with a higher trait anxiety, increased somatization, and a lower body image. Among the VVS women, nonvaginal pain catastrophizing was significantly related to reported pain during coitus. A cluster analysis revealed four subtypes of VVS women, as characterized by levels of pain and personality variables. I suggest implications for the assessment and treatment of women suffering from painful coitus.

Assessing sexual function and dyspareunia with the Female Sexual Function Index (FSFI) in women with vulvodynia

Using the Female Sexual Function Index (FSFI; Rosen et al., 2000), we assessed forty-two women with vulvodynia. Internal consistency was high (Cronbach's alphas = 0.90-0.97) for all scales. We compared scale scores to published healthy and patient sample data and found very large effect sizes (1.15-2.83), which indicated that women with vulvodynia reported significantly worse overall sexual function than women without sexual dysfunction and greater pain with sexual intercourse than women with female sexual arousal disorder. Results highlight difficulties experienced across all domains of sexual function, particularly with regard to dyspareunia, for women with vulvodynia. Findings also support the internal consistency and discriminant validity of the FSFI.

Hyperinnervation and mast cell activation may be used as histopathologic diagnostic criteria for vulvar vestibulitis

OBJECTIVE

Vestibulitis is currently diagnosed based only on clinical criteria. To achieve histopathological diagnostic criteria, we carried out a computerized image analysis method.

METHODS

Vestibular tissues removed from 40 women with severe vestibulitis were immunostained for mast cell count and degranulation by C-kit and mast cell tryptase, respectively. Vestibular nerve cells total area was evaluated after S-100 stain. Controls were 7 women aged 18-48. The images were converted to a digital signal, and analyzed using Image Proplus V4 software.

RESULTS

We found a significant increase in inflammatory infiltrate, number of mast cells and degranulated mast cells in vestibulitis compared to normal controls. The inflammatory cells were localized around the superficial minor vestibular glands. The total nerve fiber area was ten times higher in vestibulitis patients than in controls. A significant positive correlation was found between the total nerve fiber area and the number of mast cells in the vestibulitis group of patients.

CONCLUSION

We documented two diagnostic histopathological criteria for vestibulitis: (1) the presence of eight or more mast cells per 10 x 10 microscopic field, and (2) the total calculated area of the nerve fibers is ten times higher than expected. These findings re-establish the inflammatory nature of the vestibulitis. It is speculated that the trigger for the local outburst of nerve fibers could be related to the activation of the mast cells by a topical agent.

Vulvar vestibulitis syndrome: a clinical approach

Vulvar vestibulitis syndrome (VVS) is a heterogeneous, multisystemic, and multifactorial disease and is one of the leading causes of dyspareunia in fertile women. As a multisystemic disease, it involves the mucous structure of the vulvar vestibule and the immune, muscular, vascular, and nervous systems, including pain fibers and centers. As a multifactorial disease, its etiology is complex, involving biological, psychosexual, and relational factors. In this article, we discuss the progression of the disease and the impact of an often lengthy delay between the onset of symptoms and a correct diagnosis. Moreover, despite documented improvements from available treatments, VVS becomes a chronic disease unless it is diagnosed early and an integrated, pathophysiologically oriented treatment is offered in an experienced center. Health care providers would therefore benefit from approaching the condition within a pain management framework focused on the woman's chronic pain, the impact on the couple's relationship, and any associated psychological sequelae.

Serotonin and Go modulate functional states of neurons and muscles controlling C. elegans egg-laying behavior

From nematodes to humans, animals employ neuromodulators like serotonin to regulate behavioral patterns and states. In the nematode C. elegans, serotonin has been shown to act in a modulatory fashion to increase the rate and alter the temporal pattern of egg laying. Though many candidate effectors and regulators of serotonin have been identified in genetic studies, their effects on specific neurons and muscles in the egg-laying circuitry have been difficult to determine. Using the genetically encoded Ca(2+) indicator cameleon, we found that serotonin acts directly on the vulval muscles to increase the frequency of Ca(2+) transients. In contrast, we found that the spontaneous activity of the egg-laying motorneurons was silenced by serotonin. Mutations in G protein alpha subunit genes altered the responses of both vulval muscles and egg-laying neurons to serotonin; specifically, mutations in the G(q)alpha homolog egl-30 blocked serotonin stimulation of vulval muscle Ca(2+) transients, while mutations in the G(o)alpha homolog goa-1 prevented the silencing of motorneuron activity by serotonin. These data indicate that serotonin stimulates egg laying by directly modulating the functional state of the vulval muscles. In addition, serotonin inhibits the activity of the motorneurons that release it, providing a feedback regulatory effect that may contribute to serotonin adaptation.

Caenorhabditis elegans Gαq Regulates Egg-Laying Behavior via a PLCβ-Independent and Serotonin-Dependent Signaling Pathway and Likely Functions Both in the Nervous System and in Muscle

egl-30 encodes the single C. elegans ortholog of vertebrate Gαq family members. We analyzed the expression pattern of EGL-30 and found that it is broadly expressed, with highest expression in the nervous system and in pharyngeal muscle. We isolated dominant, gain-of-function alleles of egl-30 as intragenic revertants of an egl-30 reduction-of-function mutation. Using these gain-of-function mutants and existing reduction-of-function mutants, we examined the site and mode of action of EGL-30. On the basis of pharmacological analysis, it has been determined that egl-30 functions both in the nervous system and in the vulval muscles for egg-laying behavior. Genetic epistasis over mutations that eliminate detectable levels of serotonin reveals that egl-30 requires serotonin to regulate egg laying. Furthermore, pharmacological response assays strongly suggest that EGL-30 may directly couple to a serotonin receptor to mediate egg laying. We also examined genetic interactions with mutations in the gene that encodes the single C. elegans homolog of PLCβ and mutations in genes that encode signaling molecules downstream of PLCβ. We conclude that PLCβ functions in parallel with egl-30 with respect to egg laying or is not the major effector of EGL-30. In contrast, PLCβ-mediated signaling is likely downstream of EGL-30 with respect to pharyngeal-pumping behavior. Our data indicate that there are multiple signaling pathways downstream of EGL-30 and that different pathways could predominate with respect to the regulation of different behaviors.

A Neurexin-related protein, BAM-2, terminates axonal branches in C. elegans

Neuronal axons connect to multiple target cells through the formation of collateral branches, but the mechanisms that regulate this process are largely unknown. We show that BAM-2, a neurexin-related transmembrane protein, is required for development of VC motoneuron branches in the worm Caenorhabditis elegans. Expression analysis and ectopic expression experiments suggest that BAM-2 functions as a branch termination cue and reveal a mechanism for selective control of branches that sprout off a primary axon.

Increased innervation of the vulval vestibule in patients with vulvodynia

BACKGROUND

Vulval vestibulitis is a condition characterized by the sudden onset of a painful burning sensation, hyperalgesia, mechanical allodynia, and occasionally pruritus, localized to the region of the vulval vestibulus. It is considered the commonest subset of vulvodynia. Pain precipitated in the absence of nociceptor stimuli might be triggered by previous peripheral nerve injury, or by the release of neuronal mediators, which set off inappropriate impulses in nonmyelinated pain fibres sensitizing the dorsal horn neurones. The pathophysiology of vulval vestibulitis is still unclear.

OBJECTIVES

The objective of this study was to evaluate the nerve fibre density and pattern, in specimens of vulval vestibulus, in normal subjects and in patients with vestibulitis, and provide objective diagnostic criteria for this condition. Methods Twelve patients with a history of the vestibulitis type of vulvodynia, and eight normal subjects underwent biopsy of the posterior wall of the vulval vestibule. Quantitative immunohistochemistry was performed, using antisera to the general neuronal marker protein gene product (PGP) 9.5, and to the neuropeptide calcitonin gene-related peptide (CGRP), on 15- microm sections.

RESULTS

There was a statistically significant increase of density and number of PGP 9.5 immunoreactive in the papillary dermis of patients with vulvodynia of the vestibulitis type, compared with those of controls. However, the distribution pattern of the innervation showed no significant change. There were no significant differences in CGRP staining between patients and controls.

CONCLUSIONS

It is concluded that the increase of PGP 9.5 immunoreactive nerve fibres, in patients with vulvodynia, may be either secondary to nerve sprouting, or may represent neural hyperplasia. Increased innervation may be applied as an objective diagnostic finding in vulval vestibulitis syndrome.

The immunoglobulin superfamily protein SYG-1 determines the location of specific synapses in C. elegans

During nervous system development, neurons form reproducible synapses onto specific targets. Here, we analyze the development of stereotyped synapses of the C. elegans HSNL neuron in vivo. Postsynaptic neurons and muscles were not required for accurate synaptic vesicle clustering in HSNL. Instead, vulval epithelial cells that contact HSNL act as synaptic guidepost cells that direct HSNL presynaptic vesicles to adjacent regions. The mutant syg-1(ky652) has defects in synapse formation that resemble those in animals that lack vulval epithelial cells: HSNL synaptic vesicles fail to accumulate at normal synaptic locations and form ectopic anterior clusters. syg-1 encodes an immunoglobulin superfamily protein that acts in the presynaptic HSNL axon. SYG-1 protein is localized to the site of future synapses, where it initiates synapse formation and localizes synaptic connections in response to the epithelial signal. SYG-1 is related to Drosophila IrreC and vertebrate NEPH1 proteins, which mediate cell-cell recognition in diverse developmental contexts.

Vestibular tactile and pain thresholds in women with vulvar vestibulitis syndrome

Vulvar vestibulitis syndrome (VVS) is a common cause of dyspareunia in pre-menopausal women. Little is known about sensory function in the vulvar vestibule, despite Kinsey's assertion that it is important for sexual sensation. We examined punctate tactile and pain thresholds to modified von Frey filaments in the genital region of women with VVS and age- and contraceptive-matched pain-free controls. Women with VVS had lower tactile and pain thresholds around the vulvar vestibule and on the labium minus than controls, and these results were reliable over time. Women with VVS also had lower tactile, punctate pain, and pressure-pain tolerance over the deltoid muscle on the upper arm, suggesting that generalized systemic hypersensitivity may contribute to VVS in some women. In testing tactile thresholds, 20% of trials were blank, and there was no group difference in the false positive rate, indicating that response bias cannot account for the lower thresholds. Women with VVS reported significantly more catastrophizing thoughts related to intercourse pain, but there was no difference between groups in catastrophizing for unrelated pains. Pain intensity ratings for stimuli above the pain threshold increased in a parallel fashion with log stimulus intensity in both groups, but the ratings of distress were substantially greater in the VVS group than in controls at equivalent levels of pain intensity. The data imply that VVS may reflect a specific pathological process in the vestibular region, superimposed on systemic hypersensitivity to tactile and pain stimuli.

Psychophysical evidence of nociceptor sensitization in vulvar vestibulitis syndrome

Vulvar vestibulitis syndrome (VVS) is a long lasting disorder of superficial dyspareunia in young women. Quantitative sensory testing, including mechanical and temperature pain thresholds and warm/cold difference limen (WCL), was performed in the vestibular mucosa in 22 women (mean age 25.0 years) with vestibulitis and 20 control subjects (mean age 25.6 years). The tests were carried out on days 7-11 of the menstrual cycle. Patients had allodynia to mechanical testing with von Frey filaments, 14.3+/-3.1mN in the symptomatic posterior area as compared with 158+/-33.5mN in healthy subjects, P<0.0001. The pain threshold to heat was 38.6+/-0.6 degrees C in patients and 43.8+/-0.8 degrees C in controls, P<0.0001. In addition, pain threshold to cold was 21.6+/-1.2 degrees C in patients whereas cooling down to 6 degrees C was usually not painful in controls. WCL was 4.9+/-0.5 degrees C in patients and 9.6+/-1.5 degrees C in healthy subjects, P<0.01. The results are compatible with the hypothesis that patients with VVS have an increased innervation and/or sensitization of thermoreceptors and nociceptors in their vestibular mucosa.

Anatomic variability of the ilioinguinal and genitofemoral nerve: implications for the treatment of groin pain

The differential diagnosis of groin pain must consider problems of the ilioinguinal and/or genitofemoral nerve. These nerves may become injured during hernia surgery or lower quadrant surgical procedures. To treat injury to these nerves, it is critical to understand their anatomic variability. In the present study the pattern of cutaneous nerve branches in the inguinal region was investigated through dissection in 64 halves of 32 human embalmed anatomic specimens. In contrast to usual textual descriptions, four different types of cutaneous branching patterns are identified: type A, with a dominance of genitofemoral nerve in the scrotal/labial and the ventromedial thigh region. In type A, the ilioinguinal nerve gives no sensory contribution to these regions (43.7 percent). In type B, with a dominance of ilioinguinal nerve, the genitofemoral nerve shares a branch with the ilioinguinal and gives motor fibers to cremaster muscle in the inguinal canal, but has no sensory branch to the groin (28.1 percent). In type C, with a dominance of genitofemoral nerve, the ilioinguinal nerve has sensory branches to the mons pubis and inguinal crease together with an anteroproximal part of the root of the penis or labia majora. The nerve was found to share a branch with the iliohypogastric nerve (20.3 percent). In type D, cutaneous branches emerge from both the ilioinguinal and the genitofemoral nerves. Additionally, the ilioinguinal nerve innervates the mons pubis and inguinal crease together with a very anteroproximal part of the root of the penis or labia majora (7.8 percent). The described patterns of innervation were bilaterally symmetric in 40.6 percent of the cadavers. The anatomic variability of both nerves has implications for all surgeons operating in the groin region and for those caring for the patient with groin pain.

Static magnetic field therapy for pain in the abdomen and genitals

Two adolescents with debilitating, medication-resistant, chronic pain of the low back and abdomen with intermittent pain of the genitalia were diagnosed with intervertebral disk disease at spinal cord levels that correlated with their signs. Both patients had undergone multiple evaluations by physicians of different specialties and both underwent appendectomy without relief of their pain. The history of the onset of pain was important in determining the affected levels. The pain of both individuals was mimicked and localized by percussion of the vertebral spines at the level of disk protrusion. This maneuver and careful review of the history were important in making the correct diagnosis in each case. In both patients, treatment with novel magnetic devices provided rapid relief that was sustained for more than 2 years. These cases highlight the need for careful evaluation and correct diagnosis of abdominal and genital pain in young patients to avoid costly and unnecessary medical intervention and the stigma of painful debility.

Increased intraepithelial innervation in women with vulvar vestibulitis syndrome

Women with vulvar vestibulitis syndrome (VVS) suffer from severe pain and discomfort in the area around the introitus at almost any stimulus that causes pressure within the vestibule. In spite of the severe sensory symptoms present in these women, the influence of the peripheral nerves in the vulvar vestibulum has not been clarified before. In this study the nerve supply in the vestibular mucosa in women with VVS and in healthy women free from vulvar symptoms has been revealed by PGP 9.5 immunohistochemistry. The results show a significant increase in the number of intraepithelial nerve endings in women with VVS, indicating an alteration in the nerve supply in the afflicted area.

Vulvar vestibulitis syndrome and vaginismus. A case report

BACKGROUND

Recent reports have argued for a revision of the criteria used for the establishment of a diagnosis of vulvar vestibulitis syndrome (VVS). On theoretical grounds it might be hypothesized that women with VVS also suffer from vaginismus.

CASE

A young woman presented with a history, symptoms and objective findings typical of vaginismus, yet she suffered from continuous, burning pain and itching in the vestibule. Earlier in the course of the problem she had received a diagnosis VVS. The patient was treated with behavioral therapy developed for vaginismus. Notations made during the course of therapy supported the assumption that the pain and itching were conditioned responses to penetration in the same way that a vaginal muscular reflex is.

CONCLUSION

Differential diagnostic difficulties exist in the field of VVS and vaginismus. Psychophysiologic theories are needed as the basis for research to clarify the connections between different diagnostic entities associated with coital burning pain and itching in the vestibule.

Neurochemical characterization of the vestibular nerves in women with vulvar vestibulitis syndrome

Women with vulvar vestibulitis syndrome (VVS) have a distinct burning pain provoked by almost any stimuli in the area around the vaginal introitus. In a previous study we observed an increased number of intraepithelial free nerve endings in women with VVS. The aim of the present study was to neurochemically characterize the superficial nerves in the vulvar vestibular mucosa of women with VVS. Immunohistochemical methods were used to detect neuropeptides normally found in various types of nerve fibers. Calcitonin gene-related peptide, which is known to exist in nociceptive afferent nerves, was the only neuropeptide detected in the superficial nerves of the vestibular mucosa. These findings confirm our previous theory that the free nerve endings within the epithelium are nociceptors.

Localization of chromogranin, synaptophysin, serotonin, and CXCR2 in neuroendocrine cells of the minor vestibular glands: an immunohistochemical study

Sections of vulvar tissue containing minor vestibular glands (15 sections from 14 women with vulvar vestibulitis syndrome and six control sections from five asymptomatic women) were immunohistochemically stained with antibodies against chromogranin, synaptophysin, serotonin, and CXCR2. The degree of inflammation in vestibular tissue from women with and without vulvar vestibulitis syndrome was not significantly different. All vulvar minor vestibular glands contained neuroendocrine cells that expressed chromogranin to some degree. Only one case failed to express synaptophysin. The number of cells expressing chromogranin and synaptophysin was the same regardless of the degree of inflammation. However, moderate to severe inflammation was associated with a statistically significant increase in the number of cells expressing serotonin (p < 0.001) and CXCR2 (p < 0.02). It is concluded that neuroendocrine cells are present within minor vestibular glands of the vulva. The number of cells expressing the inflammatory mediator serotonin and CXCR2, the shared interleukin-8 receptor, are upregulated with inflammation. Chronic inflammation is a normal finding in vestibular tissue and does not serve as a histologic marker for vulvar vestibulitis.

[Neurotrophic basis of atrophic changes in the vagina and vulva]

The aim of the study is the analysis of morphology and biochemistry of neurovascular peculiarities of biologically active cells of connective tissue and epithelium. Surgically treated women were examined in 3 age groups--active sexual cycle, menopause and senium. Histological-histochemical, neurohistological and neurohistochemical methods and techniques were applied. Morphological pictures of connective tissue proper and epithelium reflect the physiological retroplasia process, associated with age-dependent structural and cellular transformations. This is manifested in typical peculiarities observed in the peripheral innervation and in vascular rete, quantitative and localization changes in mastocytes, chromaffin cells, macrophages, lymphocytes and leucocytes. Quantitative and qualitative rebuilding takes place in fibrous and biochemical structures of basic intracellular substance with its hyalinization. This process of simple tissue atrophy includes pathological activation. In innervation and vascularization, active restructuring coexists with the pictures of quantitative and localization changes in biologically active cells in the series of hormone-immune reactions. This is expressed by dysplasia of innervation structures with angiogenesis, while in cells, apart from apoptosis or necrosis, by the appearance of stratified epithelium (anaplasia) in the reproductive layers.

Sexual behavior changes with vulvar vestibulitis syndrome

OBJECTIVE

To study the changes in normal sexual behavior that accompany the vulvar vestibulitis syndrome and to gauge an appropriate classification for the resulting sexual dysfunction.

STUDY DESIGN

Following full medical screening, questionnaires were administered to assess sexual history, illness behavior and vulvar discomfort. Forty patients who met the criteria of vestibulitis syndrome composed the study cohort.

RESULTS

The average duration of reported vulvar pain was 33 months (range, 3-240). The cohort showed no significant differences when compared with normative data on the sexual history form in their level of sexual desire, duration of intercourse or chance of female orgasm with intercourse or masturbation. Patients were: (1) highly likely to experience vulvar pain with intercourse (P < .001), (2) highly likely to have significantly reduced arousal potential (P < .001), (3) highly likely to complain of vulvar symptoms preventing intercourse from occurring (P < .001), (4) highly likely to have a reduced interest in intercourse and to have negative feelings toward it (P < .001); and (5) highly likely to refuse a partner's sexual advances (P < .001).

CONCLUSION

In the case of vulvar vestibulitis, the most appropriate Diagnostic and Statistical Manual of Mental Disorders, fourth edition, classification appears to be sexual dysfunction due to a general medical condition.

Vestibular nerve fiber proliferation in vulvar vestibulitis syndrome

OBJECTIVE

To evaluate nerve fiber density in vestibular specimens from women operated upon for vulvar vestibulitis.

METHODS

Forty-seven women with vulvar vestibulitis syndrome underwent modified posterior vestibulectomies. Vestibular specimens were analyzed after being stained for S-100 neural tissue protein. Women were followed up for 2 years.

RESULTS

In specimens from 44 of 47 patients, the densities and numbers of nerve fibers per square unit in the preparations were greater than those in specimens from six control women. In the patients, a statistically significant linear correlation was found between inflammation and nerve bundle density in the preparations (Spearman rank correlation coefficient rs=.41; P=.005). There were no signs of infectious etiology in any preparation. No or slight postoperative dyspareunia was reported by 38 of 42 women after 6 months, 36 of 39 after 12 months, and 26 of 28 after 24 months.

CONCLUSION

Vestibular neural hyperplasia may provide a morphologic explanation of the pain in vulvar vestibulitis syndrome.

Genetic enhancers of sem-5 define components of the gonad-independent guidance mechanism controlling sex myoblast migration in Caenorhabditis elegans hermaphrodites

The migrations of the sex myoblasts in Caenorhabditis elegans hermaphrodites involve two guidance mechanism: a gonad-dependent attraction that confers precise positioning of the sex myoblasts and a gonad-independent mechanism that is sufficient for coarse positioning in the absence of the gonad (Thomas et al., 1990). Here we show that mutations in unc-53, unc-71, and unc-73 disrupt sex myoblast positioning in the absence of the gonad, while they do not affect positioning in the presence of the gonad. Thus, mutations in these genes appear to compromise the gonad-independent mechanism without affecting motility or the gonad-dependent attraction. Mutations in sem-5 confer dramatic sex myoblast positioning defects in double mutant combinations with unc-53, unc-71, or unc-73 mutations, even in the presence of the gonad. This suggests that sem-5 is required for the gonad-dependent attractive mechanism. Mutations in let-60 ras and let-341 also confer sex myoblast migration defects in an unc-53 background, implicating these genes in gonad-dependent positioning as well.

Ilioinguinal nerve entrapment following needle bladder suspension procedures

Ilioinguinal nerve entrapment is a documented complication of inguinal herniorrhaphy, inguinal lymph node dissection, and appendectomy. This article reports two clinical histories to illustrate the diagnosis and management, and outlines prevention of ilioinguinal nerve entrapment as a complication of needle suspension procedures for stress urinary incontinence.

Cell interactions control the direction of outgrowth, branching and fasciculation of the HSN axons of Caenorhabditis elegans

The two serotonergic HSN motor neurons of the nematode Caenorhabditis elegans innervate the vulval muscles and stimulate egg laying by hermaphrodites. By analyzing mutant and laser-operated animals, we find that both epithelial cells of the developing vulva and axons of the ventral nerve cord are required for HSN axonal guidance. Vulval precursor cells help guide the growth cone of the emerging HSN axon to the ventral nerve cord. Vulval cells also cause the two HSN axons to join the ventral nerve cord in two separate fascicles and to defasciculate from the ventral nerve cord and branch at the vulva. The axons of either the PVP or PVQ neurons are also necessary for the HSN axons to run in two separate fascicles within the ventral nerve cord. Our observations indicate that the outgrowth of the HSN axon is controlled in multiple ways by both neuronal and nonneuronal cells.

Sustained activation of the triceps surae muscles produced by mechanical stimulation of the genital tract of the female cat

In decerebrate cats, controlled mechanical stimulation of the perivulvar skin, the vaginal wall or the cervix uteri induced visible hind limb extension. Pressing on the cervix uteri produced the greater response. To quantify these responses, the EMG activity and the tension developed by the normally inserted triceps surae muscles were recorded. The activity induced in these muscles by stimulation of the genital canal outlasted the stimulus by many seconds or a few minutes. These effects disappeared after spinalization at the T12 level. We propose that stimulation of the vaginal canal in the female cat may induce bistability of triceps surae motoneurones.

The effect of bilateral pudendal blockade on the static urethral closure function in healthy females

OBJECTIVE

To evaluate the effect of bilateral pudendal blockade on the urethral closure function in the resting state in healthy women.

METHODS

Synchronous measurements of pressure and cross-sectional area were recorded at the bladder neck, in the high-pressure zone, and in the distal urethra before and after the pudendal blockade in ten women.

RESULTS

The blockade reduced the resting pressure significantly (P < .01) all along the urethra. The viscoelastic indices of elastance (reciprocal of compliance) and hysteresis (difference in pressure at a given degree of urethral dilation when this is increased and decreased stepwise) were significantly (P < .05) reduced.

CONCLUSIONS

The striated muscles innervated by the pudendal nerve are of paramount importance for the closure function in the resting state all along the urethra. Urethral elastance and hysteresis seem to depend on activity in the surrounding striated muscle fibers.

Ilioinguinal nerve entrapment during needle suspension for stress incontinence

The anatomy of the ilioinguinal nerve makes it vulnerable to entrapment near its exit from the superficial inguinal ring, where it lies almost directly superior to the pubic tubercle. During a 27-month period (December 1986 to March 1989), we encountered seven cases of ilioinguinal nerve entrapment following needle suspension procedures. In each case the diagnosis was made because of characteristic pain localized to the medial groin, mons, labia majora, and inner thigh. The intensity and character of the pain varied considerably, presumably depending on the time and degree of nerve compression. This paper discusses the resulting pain complex, diagnosis, pathophysiology, and options for prevention and treatment of this uncommon complication.

Pudendal neuralgia

We call attention to a group of patients with chronic vulvar burning (vulvodynia), who do not have apparent infections or easily discernible abnormal physical findings, but who on simple sensory testing have allodynia, hyperalgesia, hyperpathia, and hypoesthesia in varying permutations within the areas innervated by the pudendal nerve. We propose that pudendal neuralgia (pain along the pudendal nerve) is one of the causes of idiopathic vulvodynia. In those patients in whom a neurologic, metabolic, infectious, traumatic, or malignant cause for neuralgia is not found, medical management with tricyclic antidepressants, antiepileptic agents, or both may prove helpful. Awareness of this entity will lead to earlier diagnosis, treatment, and reassurance of patients with chronic vulvar burning.

Organogenesis in C. elegans: positioning of neurons and muscles in the egg-laying system

One of the final stages in the development of egg-laying behavior in the nematode C. elegans is the organization of 8 motor neurons (2 HSN and 6 VC cells) and 8 muscles into a motor system to control the opening of the vulva. Using mutations that disrupt the development of specific components of the egg-laying system and laser microsurgery to ablate selected precursor cells, we have determined that the guidance of the egg-laying neurons and muscles, and in particular the VC neurons and vulval muscles, into the vulval region is dependent on interactions with surrounding epithelial and gonadal tissue and appears to be independent of neuron-neuron and neuron-muscle interactions. The development of the egg-laying system can be described as a series of cell interactions in which certain cells arise through induction and subsequently provide inductive cues themselves.

[Nerve-sparing, feminizing genital reconstruction to correct genital virilism: Experience of 25 children with adrenogenital syndrome]

The reconstruction of the virilized genitalia in females with adrenogenital syndrome (AGS) is carried out sparing the dorsal neurovascular bundle either through clitoral recession or reduction with simultaneous vaginoplasty and clitoroplasty. Within seven years, 25 girls aged 6 months to 16 years (mean 2 1/2 years) with AGS had a nerve-sparing genital reconstruction with resection of the clitoral shaft in one session as described by Praetorius. 23 children had a C21-defect and 1 a C11 beta-hydroxylase defect; one child had an external virilisation. All children were followed over an average period of 50 months: 21 had a good cosmetic result, the glans had a normal blood supply and was sensitive to a prick test; in 2 girls nerve integrity was demonstrated by somato-sensory evoked potentials. 2 children had small disturbing skin folds of the newly created labia and 2 girls had a somewhat scrotal appearance of the labia. The introitus caliber measured 14 F in girls operated before 6 years of age; however, a 14- and 16-year-old required intermittent bougienage.

Neurophysiologic maps of the cutaneous innervation of the external genitalia of the ewe

The area of skin supplied by the afferent fibers in a peripheral nerve is called the cutaneous area (CA) of that nerve. The CA responsive to movement of wool or hair in the genital regions were mapped in 17 ewes, with the identifications of the peripheral nerves and of the spinal nerves contributing to the pudendal plexus being checked at necropsy. Differences were found in the origins and extent of CA of the cutaneous branches from the sacral plexus. The CA of the caudal rectal nerves and of a nerve that passed caudally between the caudal vertebrae and the ventral sacrococcygeus muscle lay lateral to the anus and in the adjacent skin of the tail. The CA of the proximal cutaneous branch and of the distal cutaneous branch from the pudendal nerve (or plexus) overlapped craniocaudally (by approx one-half) the CA of the distal cutaneous branch extending ventrally and ending just caudal to the ipsilateral mammary gland. The deep perineal nerve innervated the skin immediately lateral to the anus and vulva. The dorsal nerve of the clitoris innervated hairs on the ipsilateral half of the vulva. Other fibers in the pudendal nerve were presumed to pass into the mammary branch of the nerve. They innervated the skin ventral to the vulva, the ipsilateral mammary gland, and (in some ewes) areas of the skin cranial to the mammary gland. The CA of the genitofemoral nerve included the ipsilateral teat and the inguinal fossa.(ABSTRACT TRUNCATED AT 250 WORDS)