World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project: V. Physical examination standards in endometriosis research

OBJECTIVE

The World Endometriosis Research Foundation established the Endometriosis Phenome and Biobanking Harmonisation Project (EPHect) to create standardized documentation tools (with common data elements) to facilitate the comparison and combination of data across different research sites and studies. In 2014, 4 data research standards were published: clinician-reported surgical data, patient-reported clinical data, and fluid and tissue biospecimen collection. Our current objective is to create an EPHect standard for the clinician-reported physical examination (EPHect-PE) for research studies.

DESIGN

An international consortium involving 26 clinical and academic experts and patient partners from 11 countries representing 25 institutions and organizations. Two virtual workshops, followed by the development of the physical examination standards underwent multiple rounds of iterations and revisions.

SUBJECTS

N/A MAIN OUTCOME MEASURE(S): N/A RESULT(S): The EPHect-PE tool provides standardized assessment of physical examination characteristics and pain phenotyping. Data elements involve examination of back and pelvic girdle; abdomen including allodynia and trigger points; vulva including provoked vestibulodynia; pelvic floor muscle tone and tenderness; tenderness on unidigital pelvic examination; presence of pelvic nodularity; uterine size and mobility; presence of adnexal masses; presence of incisional masses; speculum examination; tenderness and allodynia at an extra-pelvic site (e.g., forearm); and recording of anthropometrics.

CONCLUSION(S)

The EPHect-PE standards will facilitate the standardized documentation of the physical examination, including the assessment and documentation of examination phenotyping of endometriosis-associated pelvic pain.

Stress, pain, anxiety, and depression in endometriosis-Targeting glial activation and inflammation

Endometriosis (EM) is a gynecological inflammatory disease often accompanied by stress, chronic pelvic pain (CPP), anxiety, and depression, leading to a diminished quality of life. This review aims to discuss the relationship between systemic and local inflammatory responses in the central nervous system (CNS), focusing on glial dysfunctions (astrocytes and microglia) as in critical brain regions involved in emotion, cognition, pain processing, anxiety, and depression. The review presents that EM is connected to increased levels of pro-inflammatory cytokines in the circulation. Additionally, chronic stress and CPP as stressors may contribute to the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, depleting the production of inflammatory mediators in the circulatory system and the brain. The systemic cytokines cause blood-brain barrier (BBB) breakdown, activate microglia in the brain, and lead to neuroinflammation. Furthermore, CPP may induce neuronal morphological alterations in critical regions through central sensitization and the activation of glial cells. The activation of glial cells, particularly the polarization of microglia, leads to the activation of the NLRP3 inflammasome and the overproduction of inflammatory cytokines. These inflammatory cytokines interact with the signaling pathways involved in neural plasticity. Additionally, persistent inflammatory conditions in the brain lead to neuronal death, which is correlated with a reduced volume of key brain regions such as the hippocampus. This review highlights the involvement of glial cells in the pathogenesis of the mental comorbidities of EM (i.e., pain, anxiety, and depression) and to discuss potential therapeutic approaches for targeting the inflammation and activation of microglia in key brain regions.

Facilitated Central Pain Mechanisms Across the Menstrual Cycle in Dysmenorrhea and Enlarged Pain Distribution in Women With Longer Pain History

Dysmenorrhea (DYS), or recurrent menstrual pain, is a highly prevalent pain condition among otherwise healthy women. However, the progression of DYS over time and the influence of the menstrual cycle phases need to be better understood. While the location and distribution of pain have been used to assess pain mechanisms in other conditions, they are unexplored in DYS. Thirty otherwise healthy women with severe DYS and 30 healthy control women were recruited into 3 subgroups (n = 10) according to the length of their menstrual history (<5, 5-15, or>15 years since menarche). The intensity and distribution of menstrual pain were recorded. Pressure pain thresholds at abdominal, hip, and arm sites, pressure-induced pain distribution, temporal summation of pain, and pain intensity after pressure cessation over the gluteus medius were assessed at 3 menstrual cycle phases. Compared with the healthy control women, those with DYS showed lower pressure pain thresholds in every site and menstrual cycle phase (P < .05), enlarged pressure-induced pain areas during menstruations (P < .01), and increased temporal summation and pain intensity after pressure cessation in the overall menstrual cycle (P < .05). Additionally, these manifestations were enhanced during the menstrual and premenstrual phases compared to ovulation in women with DYS (P < .01). Women with long-term DYS demonstrated enlarged pressure-induced pain distribution, enlarged menstrual pain areas, and more days with severe menstrual pain compared to the short-term DYS subgroup (P < .01). Pressure-induced and menstrual pain distributions were strongly correlated (P < .001). These findings suggest that severe DYS is a progressive condition underscored by facilitated central pain mechanisms associated with pain recurrence and exacerbation. PERSPECTIVE: Enlarged pressure-induced pain areas occur in DYS, associated with the length of the condition and the distribution of menstrual pain. Generalized hyperalgesia is present throughout the entire menstrual cycle and intensifies during premenstrual and menstrual phases.

Endometriosis leads to central nervous system-wide glial activation in a mouse model of endometriosis

BACKGROUND

Chronic pelvic pain (CPP) is a common symptom of endometriosis. Women with endometriosis are also at a high risk of suffering from anxiety, depression, and other psychological disorders. Recent studies indicate that endometriosis can affect the central nervous system (CNS). Changes in the functional activity of neurons, functional magnetic resonance imaging signals, and gene expression have been reported in the brains of rat and mouse models of endometriosis. The majority of the studies thus far have focused on neuronal changes, whereas changes in the glial cells in different brain regions have not been studied.

METHODS

Endometriosis was induced in female mice (45-day-old; n = 6-11/timepoint) by syngeneic transfer of donor uterine tissue into the peritoneal cavity of recipient animals. Brains, spines, and endometriotic lesions were collected for analysis at 4, 8, 16, and 32 days post-induction. Sham surgery mice were used as controls (n = 6/timepoint). The pain was assessed using behavioral tests. Using immunohistochemistry for microglia marker ionized calcium-binding adapter molecule-1 (IBA1) and machine learning "Weka trainable segmentation" plugin in Fiji, we evaluated the morphological changes in microglia in different brain regions. Changes in glial fibrillary acidic protein (GFAP) for astrocytes, tumor necrosis factor (TNF), and interleukin-6 (IL6) were also evaluated.

RESULTS

We observed an increase in microglial soma size in the cortex, hippocampus, thalamus, and hypothalamus of mice with endometriosis compared to sham controls on days 8, 16, and 32. The percentage of IBA1 and GFAP-positive area was increased in the cortex, hippocampus, thalamus, and hypothalamus in mice with endometriosis compared to sham controls on day 16. The number of microglia and astrocytes did not differ between endometriosis and sham control groups. We observed increased TNF and IL6 expression when expression levels from all brain regions were combined. Mice with endometriosis displayed reduced burrowing behavior and hyperalgesia in the abdomen and hind-paw.

CONCLUSION

We believe this is the first report of central nervous system-wide glial activation in a mouse model of endometriosis. These results have significant implications for understanding chronic pain associated with endometriosis and other issues such as anxiety and depression in women with endometriosis.

Osteoarthritis Pain in Old Mice Aggravates Neuroinflammation and Frailty: The Positive Effect of Morphine Treatment

Knee osteoarthritis is a common cause of pain and disability in old subjects. Pain may predispose to the development of frailty. Studies on mechanisms underlying pain in osteoarthritis models during aging are lacking. In this work, we used the monosodium iodoacetate model of osteoarthritis in adult (11-week-old) and old (20-month-old) C57BL/6J mice to compare hypersensitivity, locomotion, neuroinflammation, and the effects of morphine treatment. After osteoarthritis induction in adult and old mice, weight-bearing asymmetry, mechanical allodynia, and thermal hyperalgesia similarly developed, while locomotion and frailty were more affected in old than in adult animals. When behavioral deficits were present, the animals were treated for 7 days with morphine. This opioid counteracts the behavioral alterations and the frailty index worsening both in adult and old mice. To address the mechanisms that underlie pain, we evaluated neuroinflammatory markers and proinflammatory cytokine expression in the sciatic nerve, DRGs, and spinal cord. Overexpression of cytokines and glia markers were present in osteoarthritis adult and old mice, but the activation was qualitatively and quantitatively more evident in aged mice. Morphine was able to counteract neuroinflammation in both age groups. We demonstrate that old mice are more vulnerable to pain's detrimental effects, but prompt treatment is successful at mitigating these effects.

Myofascial Pain Syndrome in Women with Primary Dysmenorrhea: A Case-Control Study

There is limited information on myofascial trigger points (MTrPs) and specific symptoms of chronic pelvic pain and, more specifically, dysmenorrhea. The objective of this study was to determine whether patients suffering from primary dysmenorrhea present alterations in mechanosensitivity and pain patterns, and greater presence of MTrPs in the abdominal and pelvic floor muscles. A case-control study was carried out with a total sample of 84 participants distributed based on primary dysmenorrhea and contraceptive treatment. The sample was divided into four groups each comprising 21 women. Data on pain, quality of life, and productivity and work absenteeism were collected; three assessments were made in different phases of the menstrual cycle, to report data on pressure pain threshold, MTrP presence, and referred pain areas. One-way ANOVA tests showed statistically significant differences (p < 0.01) between the groups, for the Physical Health domain and the total score of the SF-12 questionnaire, and for all the domains of the McGill questionnaire; but no significant differences were found in the data from the WPAI-GH questionnaire. Statistically significant data (p < 0.01) were found for mechanosensitivity in the abdominal area and limbs, but not for the lumbar assessment, within the group, with very few significant intergroup differences. The frequency of active MTrPs is higher in the groups of women with primary dysmenorrhea and during the menstrual phase, with the prevalence of myofascial trigger points of the iliococcygeus muscle being especially high in all examination groups (>50%) and higher than 70% in women with primary dysmenorrhea, in the menstrual phase, and the internal obturator muscle (100%) in the menstrual phase. Referred pain areas of the pelvic floor muscles increase in women with primary dysmenorrhea.

Postoperative pain and the need for intervention after sacrospinous ligament hysteropexy compared to colpopexy: a retrospective cohort study

OBJECTIVES

To compare postoperative pain between patients undergoing sacrospinous ligament colpopexy (SSLF) and hysteropexy (SSLH).

METHODS

This was a retrospective cohort study of all patients undergoing native tissue SSLF and SSLH between January 2013 and March 2020. The electronic medical record was queried for demographic and perioperative data until the postoperative visit. The primary outcome was a composite incidence of any of the following: telephone calls, urgent office visits, additional analgesic prescriptions and need for intervention for pain in the buttocks, posterior thigh or perirectal area. Secondary outcomes were the incidence of persistent pain at the postoperative visit and perioperative risk factors associated with reported pain.

RESULTS

A total of 406 patients met inclusion criteria (308 SSLF, 98 SSLH). The composite pain outcome was seen in 99 patients (24.4%; 95% CI 20.5%-28.8%), and there was no statistical difference between cohorts. Persistent pain was seen in 15.6% and 13.3% of SSLF and SSLH patients at 6 weeks (p = 0.58). Twelve patients (3.0%) underwent interventions for pain, including physical therapy (2), trigger point injections (5) and suture release (5). Compared to SSLF patients, SSLH patients were more likely to need interventions (7 [7.1%] vs. 5 [1.6%], p = 0.005) and office visits (14 [14.3%] vs. 13 [4.2%], p = 0.0005) for pain.

CONCLUSIONS

There was no difference in the overall incidence of postoperative pain between patients who underwent SSLF or SSLH. However, patients who underwent hysteropexy were more likely to need intervention and office evaluation for postoperative pain.

Effectiveness of intracavitary monopolar dielectric radiofrequency in women with endometriosis-associated pain: A case series

BACKGROUND

and Purpose: Endometriosis-associated pain is the main cause of chronic pelvic pain in women. Endometriosis has a significant negative impact across different domains of patients' quality of life. This study aimed to evaluate the efficacy of an intracavitary application of monopolar dielectric radiofrequency in women with endometriosis-associated pain.

PATIENT PRESENTATION

Five women with endometriosis received 25 sessions of an intracavitary application of monopolar dielectric radiofrequency within three months. Outcomes, including quality of life, sex interference (Endometriosis Health Profile [EHP]-30 + section C), myofascial pain syndrome (myofascial trigger points), pain intensity (Visual Analogue Scale), frequency and referral pattern, pressure pain thresholds, allodynia and neuropathic pain (modified DN4), were examined both during and outside menses, after intervention and six months later.

RESULTS

Clinically meaningful improvements were achieved by most participants regarding pelvic pain intensity, abdominal sensitivity, and myofascial pain of the pelvic floor.

CONCLUSION

This study lays the foundation for future in-depth research, suggesting that monopolar dielectric radiofrequency could be helpful in improving the symptomatology and quality of life of women with endometriosis, also in patients who are unresponsive to medical and/or surgical treatments, or who cannot undergo them in the short term.

Preoperative quantitative sensory testing and robot-assisted laparoscopic hysterectomy for endometrial cancer: can chronic postoperative pain be predicted?

Objectives Chronic postoperative pain is prevalent after robot-assisted laparoscopic hysterectomy for endometrial cancer. Preoperative Quantitative Sensory Testing (QST) has been utilized to identify patients at risk of developing chronic postoperative pain after a range of surgical procedures. The aim of this prospective, observational study was to (1) determine the prevalence of chronic postoperative pain, (2) assess selected preoperative risk factors for chronic postoperative pain, and (3) evaluate if preoperative QST profiling could predict the development of chronic postoperative pain following robot-assisted laparoscopic hysterectomy for endometrial cancer. Methods One-hundred and sixty consecutive patients were included and handheld pressure algometry, cuff pressure algometry, temporal summation of pain, conditioned pain modulation, and heat pain thresholds were assessed prior to surgery. Patients were asked to fill out a questionnaire concerning pain in the pre- and post-operative time period six months after surgery. Chronic postoperative pain was defined as persistent, moderate to severe pain (mean visual analogue scale (VAS)≥3) on a daily basis six months after surgery. Results The prevalence of chronic postoperative pain after robot-assisted laparoscopic hysterectomy for endometrial cancer was of 13.6% (95% CI 8.4-20.4%). Patients that would develop chronic postoperative pain had a lower BMI (p=0.032), a higher prevalence of preoperative pelvic pain (p<0.001), preoperative heat pain hyperalgesia (p=0.043) and a higher level of acute postoperative pain (p<0.001) when compared to patients that would not develop chronic postoperative pain. A logistic regression model demonstrated that the presence of preoperative pelvic pain was a significant, independent predictive risk factor for development of chronic postoperative pain (OR=6.62, 95% CI 2.26-19.44), whereas none of the QST parameters could predict postoperative pain. Conclusions Preoperative QST assessment could not predict the development of chronic postoperative pain despite preoperative heat pain hyperalgesia in patients that would develop chronic postoperative pain.

Correction to: Chronic Postoperative Pain After Robot-Assisted Laparoscopic Hysterectomy for Endometrial Cancer by Lunde S, Petersen KK, Kugathasan P, Arendt-Nielsen L and Søgaard-Andersen E. Journal of Gynecologic Surgery 2019;35(3);140-146. DOI: 10.1089/gyn.2018.0068

[This corrects the article DOI: 10.1089/gyn.2018.0068.].

Experimental evaluation of central pain processes in young women with primary dysmenorrhea

Primary dysmenorrhea (PD; menstrual pain without an underlying medical condition) is associated with enhanced pain sensitivity and temporal summation (TS) in adult women, which may reflect the presence of central pain processes. Research in this area has been limited by focusing on only adult populations and incomplete assessments of central sensitization. The current study explored both excitatory and inhibitory measures of pain processing in girls and young adult women with and without PD. Thirty-two young women with PD and 34 healthy controls underwent laboratory pain testing during each of 3 menstrual cycle phases (menstrual, ovulatory, and midluteal), which included measures of pain tolerance and threshold, TS, and conditioned pain modulation. Results indicated enhanced pain sensitivity in young women with PD as measured by heat pain tolerance and Average Pain50 (P50), compared with healthy controls. These group differences were evident at all phases of the menstrual cycle. No group differences in cold pain tolerance, TS, or conditioned pain modulation were evident at any phase of the menstrual cycle. These data suggest some evidence of central sensitization in young women with PD, although no evidence of enhanced excitatory or deficient inhibitory mechanisms were observed. Future research should focus on identifying other potential phenotypes for PD to determine those at risk of developing other pain problems.

Chronic pain intervention using pulsed shortwave therapy: the relationship between pain demographics and central sensitization inventory

Aim: The central sensitization inventory (CSI) is a validated, patient-reported questionnaire that quantifies symptoms of hypersensitivity disorders such as chronic pain, for which central sensitization (CS) may be the etiology. Objective: To investigate the analgesic effectiveness of ActiPatch and analyze the relationship between baseline CSI scores and demographics of chronic pain sufferers. Methods: Upon completing a 7-day ActiPatch trial, baseline CSI scores along with other assessment measures were obtained via e-mail from 174 chronic pain sufferers. Conclusion: CSI scores were positively correlated with gender (higher for women), baseline visual analog scale scores and pain duration. ActiPatch was found to be effective in reducing baseline pain for all subjects by an average of 4.3 visual analog scale points.

Widespread Pressure Pain Hypersensitivity, Health History, and Trigger Points in Patients with Chronic Neck Pain: A Preliminary Study

Background

Pain sensitivity in chronic neck pain patients may be influenced by health conditions related to higher levels of widespread pressure pain hypersensitivity (sensitization). Trigger points have also been reported to play a role in the sensitization process.

Objectives

To investigate the association between pressure pain thresholds, trigger points, and health conditions in patients with chronic neck pain.

Design

Original research, preliminary study.

Setting

A private clinic.

Subjects

Thirty-four chronic mechanical neck pain patients and 34 chronic whiplash-associated neck pain patients, giving a final sample of 68 chronic neck pain patients.

Methods

Patients underwent an assessment of pressure pain thresholds over the upper trapezius, extensor carpi radialis longus, and tibialis anterior muscles and were screened for the presence of trigger points in the upper trapezius muscle. Further, information about health history conditions was obtained and collected in a form.

Results

Significantly negative correlations between all pressure pain thresholds and duration of health history conditions were found (all P &lt; 0.02). Significantly lower pressure pain thresholds (all P &lt; 0.01) were found in patients with active trigger points as compared with those with latent trigger points.

Conclusion

Widespread pressure pain hypersensitivity was associated with duration of health history conditions, suggesting that long-lasting health complaints may act as a triggering/perpetuating factor, driving sensitization in individuals with chronic neck pain. Active trigger points may be associated with higher widespread pressure hypersensitivity.

The comorbidities of dysmenorrhea: a clinical survey comparing symptom profile in women with and without endometriosis

Purpose

Dysmenorrhea is a common disorder that substantially disrupts the lives of young women. The frequency of 14 associated symptoms both within and outside the pelvis was determined.

Patients and methods

Symptom questionnaires were completed by 168 women with dysmenorrhea, allocated to three groups based on their diagnostic status for endometriosis confirmed (Endo+), endometriosis excluded (Endo-), or endometriosis diagnosis unknown (No Lap). Those with endometriosis confirmed were further divided into current users (Endo+ Hx+) and non-users of hormonal treatments (Endo+ Hx-). Users of hormonal treatments were further divided into users (Endo+ Hx+ LIUCD+) and non-users (Endo+ Hx+ LIUCD-) of a levonorgestrel-releasing intra-uterine contraceptive device (LIUCD). The frequency and number of symptoms within groups and the effect of previous distressing sexual events were sought.

Results

Women with and without endometriosis lesions had similar symptom profiles, with a mean of 8.5 symptoms per woman. Only 0.6% of women reported dysmenorrhea alone. The presence of stabbing pelvic pains was associated with more severe dysmenorrhea (P=0.006), more days per month of dysmenorrhea (P=0.003), more days per month of pelvic pain (P=0.016), and a diagnosis of migraine (P=0.054). The symptom profiles of the Endo+ Hx+ and Endo+ Hx- groups were similar. A history of distressing sexual events was associated with an increased number of pain symptoms (P=0.003).

Conclusion

Additional symptoms are common in women with dysmenorrhea, and do not correlate with the presence or absence of endometriosis lesions. Our study supports the role of central sensitization in the pain of dysmenorrhea. The presence of stabbing pelvic pains was associated with increased severity of dysmenorrhea, days per month of dysmenorrhea, days per month of pelvic pain, and a diagnosis of migraine headache. A past history of distressing sexual events is associated with an increased number of pain symptoms.

Behavioural and neural responses to aversive visceral stimuli in women with primary dysmenorrhoea

BACKGROUND

Chronic pelvic pain, in particular dysmenorrhoea, is a significant yet unresolved healthcare problem in gynaecology. As interoceptive sensitivity and underlying neural mechanisms remain incompletely understood, this functional magnetic resonance imaging (fMRI) study assessed behavioural and neural responses to visceral stimuli in primary dysmenorrhoea (PMD).

METHODS

Women with PMD (N = 19) without psychological comorbidity and healthy women (N = 20) were compared with respect to visceral sensory and pain thresholds, and to neural responses to individually calibrated mildly painful and painful rectal distensions implemented during scanning. Trial-by-trial ratings of perceived intensity were accomplished with visual analogue scales (VAS).

RESULTS

Although women with dysmenorrhoea reported significantly higher chronic pain intensity and pain interference with daily life activities (p < 0.01, assessed with the West Haven-Yale Multidimensional Pain Inventory), there were no differences between groups in visceral sensitivity and mean trial-by-trial VAS ratings were virtually identical. Analysis of neural responses revealed activation in brain regions previously shown to be involved in the processing of visceral stimuli with differences between painful and mildly painful stimulation, but no group differences were found even when using a liberal statistical threshold.

CONCLUSIONS

Dysmenorrhoea patients show unaltered perceptual and neural responses to experimental interoceptive stimuli. Despite limited sample size, these negative results argue against a generalized sensitization towards interoceptive stimuli in patients without psychological comorbidities. Future studies should clarify the role of psychosocial factors in central sensitization using more pain region-specific models in larger and clinically more heterogeneous samples.

SIGNIFICANCE

Despite higher chronic pain and pain interference with daily life activities, women with primary dysmenorrhoea do not differ from healthy women with respect to visceral sensitivity or neural processing of aversive interoceptive stimuli induced by rectal distensions. Generalized sensitization may be present only in subgroups with pronounced psychosocial or psychiatric disturbances.

Nonsteroidal antiinflammatory drug resistance in dysmenorrhea: epidemiology, causes, and treatment

Although nonsteroidal antiinflammatory drugs can alleviate menstrual pain, about 18% of women with dysmenorrhea are unresponsive, leaving them and their physicians to pursue less well-studied strategies. The goal of this review is to provide a background for treating menstrual pain when first-line options fail. Research on menstrual pain and failure of similar drugs in the antiplatelet category suggested potential mechanisms underlying nonsteroidal antiinflammatory drug resistance. Based on these mechanisms, alternative options may be helpful for refractory cases. This review also identifies key pathways in need of further study to optimize menstrual pain treatment.

Negative laparoscopy unveiled

Introduction:

Studies indicate a variable proportion of laparoscopies done for the management of non-acute pelvic pain that do not identify visible pathology and are called negative laparoscopies. Possible explanations have included undetected endometriosis, observer error, and/or neural tissues in the endometrium acting as nociceptive input. The goal was to compare demographic and pain testing measures between women with negative laparoscopies and confirmed endometriosis in a cohort of women presenting with chronic pelvic pain.

Methods:

Women with chronic pelvic pain (n = 255) provided written consent for the study prior to entry. Data were collected at the time of clinic visit and entered contemporaneously into SPSS. Pain sensitization was identified as the presence of cutaneous allodynia. Clinical, pain, and pain sensitization variables were compared using Student’s t-test.

Results:

The frequency of negative laparoscopy was 13.7% (35 cases) and that of confirmed endometriosis was 27.1% (69 cases). There were no differences between women with a negative laparoscopy and women with confirmed endometriosis in clinical, dysmenorrhea, or pain testing measurements.

Conclusion:

The data suggest in the absence of endometriotic tissue in the pelvis, chronic visceral pain may result from a uterine origin and result in a generalized pattern of pain and pain sensitization.

Intensity Dependence of Auditory Evoked Potentials in Primary Dysmenorrhea

Some studies suggest that women with primary dysmenorrhea have distinct emotional or personality features. For example, they might exaggerate their responses to external stimuli, such as to intensity-increasing auditory stimuli. Fifteen women with primary dysmenorrhea and 15 healthy women were invited to undergo tests of the intensity dependence of auditory evoked potentials (IDAEP), the Functional and Emotional Measure of Dysmenorrhea, and the Plutchik-van Praag Depression Inventory. Study participants with dysmenorrhea showed higher Functional and Emotional scale scores and stronger IDAEP. Regarding the IDAEP generation, the source inversion of N1 and P2 disclosed the activated bilateral superior temporal gyri, medial and superior prefrontal gyri in all participants, and additionally, the middle frontal gyri in dysmenorrhea patients. We report a pronounced IDAEP in primary dysmenorrhea, which indicates the decreased cerebral serotonergic innervations and points to increased activations in the prefrontal and frontal areas in the disorder.

PERSPECTIVE

Using an IDAEP technique, the authors found decreased serotonergic innervation and altered cerebral activation in women with primary dysmenorrhea, which might offer some pharmacotherapeutic clues for the disorder.

Experimental and procedural pain responses in primary dysmenorrhea: a systematic review

Primary dysmenorrhea (PD) has been the focus of a number of experimental pain studies. Although a number of reviews exist, few have critically evaluated the existing body of research on PD and experimental and procedural pain. Data from 19 published research articles that include women with PD and responses to an experimental or procedural pain stimulus (or stimuli) suggest that women with PD may have elevated pain reactivity, as compared to women without PD. This pattern appears to be true across different phases of the menstrual cycle. However, there is an abundance of conflicting findings, which may be due to significant methodological issues such as inconsistent definitions of PD, wide variation in experimental pain methodologies, and inaccurate assessment of the menstrual cycle. Future research should focus on identifying specific symptoms (i.e., pain threshold ratings) to more clearly define what constitutes PD, establish reliable and valid laboratory testing protocols, and assess the menstrual cycle with greater precision.

Pain Catastrophizing Predicts Menstrual Pain Ratings in Adolescent Girls with Chronic Pain

OBJECTIVES

The current study aimed to explore relationships among self-reported menstrual pain ratings, acute laboratory pain, pain catastrophizing, and anxiety sensitivity in a sample of girls without pain (No Pain group) and girls with a chronic pain condition (Chronic Pain group).

SETTING

A laboratory at an off-campus Medical School office building.

SUBJECTS

Eighty-four postmenarchal girls (43 No Pain, 41 Chronic Pain) ages 10-17 participated in the study.

METHODS

All participants completed self-report questionnaires assessing menstrual pain, pain catastrophizing, and anxiety sensitivity and completed a cold pressor task. Pain intensity during the task was rated on a 0 (no pain) to 10 (worst pain possible) numeric rating scale.

RESULTS

After controlling for age, average menstrual pain ratings (without medication) were significantly correlated with cold pressor pain intensity for the No Pain group only. In the Chronic Pain group, menstrual pain ratings were significantly correlated with pain catastrophizing and anxiety sensitivity. In a multiple linear regression analysis, after controlling for age, only pain catastrophizing emerged as a significant predictor of menstrual pain ratings in the Chronic Pain group.

CONCLUSION

Results demonstrate differences in relationships among menstrual pain, acute laboratory pain, and psychological variables in girls with no pain compared with girls with chronic pain. In addition, pain catastrophizing may be a particularly salient factor associated with menstrual pain in girls with chronic pain that warrants further investigation.

Heightened cold pain and pressure pain sensitivity in young female adults with moderate-to-severe menstrual pain

This study investigated the association between menstrual pain severity and psychophysical measures of cold and pressure pain sensitivity. A cross-sectional design was used with young women (n = 432) from the Western Australian Pregnancy Cohort (Raine) Study. Menstrual pain severity and oral contraception use was obtained from questionnaires at 20 and 22-year follow-ups. A visual analog scale (VAS; range from 0 [none] to 10 [unbearable]) was used to measure menstrual pain severity at both 20 and 22 years over the 3-year period, with 3 groups created: (1) no pain or mild pain (VAS 0-3), (2) at least moderate pain at a minimum of 1 of the 2 time points (hereafter named "mixed)", and (3) severe pain (VAS 8-10). Cold pain sensitivity (dorsal wrist) and pressure pain sensitivity (lumbar spine, upper trapezius, dorsal wrist, and tibialis anterior) were assessed using standardised quantitative sensory testing protocols. Confounding variables included number of musculoskeletal pain sites, oral contraceptive use, smoking, physical activity, body mass index, psychological distress, and sleep. Severe menstrual pain and mixed menstrual pain were positively associated with heightened cold pain sensitivity (distant from menstrual pain referral site) and pressure pain sensitivity (local to menstrual pain referral site). These associations remained significant after adjusting for potential confounding variables including multisite musculoskeletal pain. Our findings suggest peripheral and central neurophysiological mechanisms contributing to heightened pain sensitivity in young women with moderate and severe menstrual pain. These data highlight the need for innovative management approaches to attenuate the negative impact of severe menstrual pain in young women.