Reduced pain thresholds and signs of sensitization in women with persistent pelvic pain and suspected endometriosis

Treatment of acute dysmenorrhoea and pelvic pain syndrome of uterine origin with myometrial botulinum toxin injections under hysteroscopy: A pilot study

BACKGROUND

Acute dysmenorrhoea in women which has been shown to be anatomically negative for endometriosis is a very common condition. It is frequently associated with Chronic Pelvic Pain (CPP) from uterine origin, including painful uterine contractions and deep dyspareunia. We call this association Painful Uterine Syndrome (PUS).

SEARCH STRATEGY

In these women in failure of the usual treatments, we proposed a new treatment, with Uterine Toxin Botulinic injections (BTX) under hysteroscopy, as a compassionate option, among women in severe pain and therapeutic failure. Indeed, increased uterine contractility has been confirmed using cine magnetic resonance imaging in patients with acute dysmenorrhea and PUS. These findings, associated with the hypothesis of a possible uterine sensitization on the same model as irritable bowel syndrome (IBS) or painful bladder syndrome (PBS), led to the application of botulinum toxin (BTX) injections under hysteroscopy of the uterine myometrium in this indication.

MATERIAL AND METHODS

In 2018, we conducted an open-label non comparative study, on 30 patients, with severe dysmenorrhea and PUS in therapeutic failure situation. All women had failure of usual treatments, with painkillers, anti-inflammatory drugs, contraceptive pill, menstrual suppressant therapy and a negative MRI and laparoscopy. The BTX units (200 IU of Incobotulinum-toxin A) were evenly distributed in the anterior and posterior myometrial wall under hysteroscopic control. Patients were reviewed between 8 and 12 weeks after BTX injections and then, at 6 months.

MAIN RESULTS

Median VAS scores were significantly improved at 8-12 weeks follow up for dysmenorrhoea, deep dyspareunia, and pelvic pain outside of menstruation. Quality of life scores all improved dramatically. No major side effect has been reported in this pilot study. At 6 months, 12 patients (40 %), were given new injections for pain reccurence. But 14 patients (47 %), were still improved and did not require repeat injection at that time. 4 patients, were improvement was not significant, did not ask for repat BTX injections. These patients were all positive for Pelvic Sensitization criteria.

CONCLUSIONS

Uterine BTX injection could be a very interesting therapeutic option in women with acute dysmenorrheoa and PUS in therapeutic failure. Only long-term randomised studies will be able to confirm that BTX injections are useful as a treatment for this condition. The randomised long-term study, Uteroxine, will shortly release its results.

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.

Psychometric evaluation of the Swedish version of the 30-item endometriosis health profile (EHP-30)

Background

The 30-Item Endometriosis Health Profile (EHP-30) is a specific instrument measuring quality of life among women with endometriosis. Although the Swedish version of EHP-30 is widely used in research and clinical settings, it has not yet been evaluated psychometrically. Ensuring validity and reliability is of most importance when using translated instruments. Therefore, the aim of the study was to evaluate the psychometric properties of the Swedish version of the EHP-30.

Methods

This study was conducted at a Swedish referral university hospital specializing in endometriosis. Data collection was performed in January 2013. The EHP-30 was sent to 369 randomly selected women with a laparoscopy-verified endometriosis diagnosis. The psychometric evaluation included evaluation of data completeness, score distributions, floor and ceiling effects, internal consistency, factor analysis and test-retest reliability.

Results

Out of the 211 women with endometriosis who answered the questionnaire, 128 were native Swedish speakers who had experienced symptoms of endometriosis during the past 4 weeks, and were included in the psychometric evaluation. Data completeness was 99.5%. The highest median score was found in the Control and Powerlessness subscale, and lowest in Pain. Distributions towards ill health were found in all subscales except for the pain subscale, but there were no noteworthy floor or ceiling effects. Internal consistency was good (Cronbach’s α 0.83–0.96). Factor analysis could roughly confirm three of the five subscales. The test-rest analysis showed good reliability. Scores were systematically lower during the second measurement.

Conclusions

We conclude that the Swedish version of EHP-30 is a valid and reliable instrument to measure health-related quality of life in women with endometriosis. It is understandable, acceptable and usable and can be recommended for use in clinical daily routines and for research purposes.

Endometriosis: current challenges in modeling a multifactorial disease of unknown etiology

Endometriosis is a chronic inflammatory hormone-dependent condition associated with pelvic pain and infertility, characterized by the growth of ectopic endometrium outside the uterus. Given its still unknown etiology, treatments usually aim at diminishing pain and/or achieving pregnancy. Despite some progress in defining mode-of-action for drug development, the lack of reliable animal models indicates that novel approaches are required. The difficulties inherent to modeling endometriosis are related to its multifactorial nature, a condition that hinders the recreation of its pathology and the identification of clinically relevant metrics to assess drug efficacy. In this review, we report and comment endometriosis models and how they have led to new therapies. We envision a roadmap for endometriosis research, integrating Artificial Intelligence, three-dimensional cultures and organ-on-chip models as ways to achieve better understanding of physiopathological features and better tailored effective treatments.

A novel view of the problem of Osteoarthritis in experimental rat model

Introduction: The article presents the results of the functional tests to improve the assessment of MIA-induced osteoarthritis development and the effectiveness of NSAID therapy.

Materials and methods: In the study, 26 male SD rats were used. MIA-induced osteoarthritis was simulated in the right knee joint. After an intra-articular injection of MIA, the animals were treated with ibuprofen and meloxicam. Pain assessment was studied in the following functional tests: incapacitance (hind limb weight bearing) test, von Frey test (mechanical allodynia), grip strength test, and knee diameter measurement. At the end of the study, a histological analysis of the knee joint was performed.

Results and discussion: An intra-articular MIA injection reduced 1.5 times the paw withdrawal threshold. In the rats that suffered MIA-induced osteoarthritis, the difference between the diameters of the intact and injected joints was 1.05 mm, compared to 0.03 mm difference in the control group. Hind limb weight bearing asymmetry was 89.5% when simulating MIA-induced osteoarthritis. The muscular hind limb grip strength in rats with MIA-induced osteoarthritis was significantly reduced on 3rd and 7th days after simulating osteoarthritis. Ibuprofen and meloxicam showed significant efficacy in all the above tests, although ibuprofen effectiveness was more pronounced than that of meloxicam.

Conclusion: The following functional tests were identified as the most significant and sufficient to assess the development of MIA-induced osteoarthritis and analgesic efficacy of NSAIDs: incapacitance test, allodynia test (von Frey filaments), measurement of hind limb grip strength and measurement of the diameter of the inflamed knee joint. The histological analysis made it possible to confirm the correspondence of the physiological response and pathological changes in the knee joint.

Pathophysiological Basis of Endometriosis-Linked Stress Associated with Pain and Infertility: A Conceptual Review

Women with endometriosis are often under stress due to the associated pain, infertility, inflammation-related and other comorbidities including cancer. Additionally, these women are also under stress due to taboos, myths, inter-personal troubles surrounding infertility and pain of the disease as well as due to frequent incidences of missed diagnosis and treatment recurrence. Often these women suffer from frustration and loss of valuable time in the prime phase of life. All these complexities integral to endometriosis posit a hyperstructure of integrative stress physiology with overt differentials in effective allostatic state in women with disease compared with disease-free women. In the present review, we aim to critically examine various aspects of pathophysiological basis of stress surrounding endometriosis with special emphasis on pain and subfertility that are known to affect the overall health and quality of life of women with the disease and promising pathophysiological basis for its effective management.

Estimate of the proportion of uncertain diagnoses of pudendal neuralgia in women with chronic pelvic-perineal pain: A systematic review with a descriptive data synthesis

BACKGROUND

There is a gap between pudendal neuralgia (PN) due to pudendal entrapment syndrome and PN without pudendal entrapment syndrome. The latter could have atypical symptoms.

AIM

Defining a rate of atypical PN from a clinical series of female patients with chronic pelvic-perineal pain.

METHODS

The atypical PN was defined as a pain not meeting clinical criteria for pudendal entrapment syndrome. The effect size was the rate of atypical PN. Such a rate was expected to be found among patients screened for enrollment in clinical series on pudendal neuropathic pain. A systematic search was performed looking for clinical series on PN. Studies must report information on female patients, pelvic-perineal pain, at least a clinical criterion for diagnosing the pudendal neurogenic origin of pain, the proportion of patients with pain not meeting the clinical criterion/a for diagnosing the pudendal entrapment pain.

RESULTS

From 2637 references, nine studies were included for qualitative analysis. Three of them were not suitable for data synthesis: one assessed the rate of PN after hip arthroscopy; second enrolled miscellaneous patients, a third investigated patients with gynecological diseases. Six studies involved patients with suspicion of pudendal entrapment symptoms (205 patients observed), allowing data synthesis. One of these series was judged as being of good quality. The overall rate of atypical PN is 0.013 (95% confidence interval, 0.008-0.021), I² 0%. Further analysis suggests the risk of bias for all studies.

CONCLUSIONS

Atypical PN in females is low when clinical criteria for pudendal entrapment syndrome are applied.

Endometriosis and pain in the adolescent- striking early to limit suffering: A narrative review

Endometriosis, a condition in which uterine tissue grows outside the uterus, is a debilitating disease, affecting millions of women and costing the United States approximately $78 billion annually in pain- related disability. It is also the leading cause of chronic pelvic pain (CPP), which is often unresponsive to existing treatments. Adolescent women with the disease are at particular risk as there are often significant diagnostic delays, which in turn can exacerbate pain. Research and treatment guidelines for adolescents with endometriosis are largely based on studies for adult women due to the limited number of studies focusing on adolescents. The current paper critically reviews the literature as it pertains to endometriosis pathophysiology, mechanisms contributing to CPP, and treatment implications and recommendations with a focus on gaps related to adolescents.

Associations between pain thresholds for heat, cold and pressure, and Pain Sensitivity Questionnaire scores in healthy women and in women with persistent pelvic pain

BACKGROUND

The Pain Sensitivity Questionnaire (PSQ) is a self-rating instrument developed as a time- and cost-saving alternative to quantitative sensory testing (QST). The aims of the study were to assess (a) the associations between PSQ scores and QST in women with persistent pelvic pain and in pain-free controls and (b) to what extent demographic variables and psychological distress influenced PSQ scores.

METHODS

Fifty-five healthy women and 37 women with persistent pelvic pain participated. All filled in the PSQ and Hospital Anxiety and Depression Scale and had QST (heat, cold and pressure pain thresholds) performed on six locations on the body. Information on age, body mass index, smoking habits and pain duration were collected. Principal component analysis and orthogonal partial least square regressions were used.

RESULTS

The patients scored significantly higher on PSQ than the controls. Significant multivariate correlations between pain thresholds and PSQ scores were found only in the patient group. In the patient group, the heat and cold pain thresholds correlated more strongly with PSQ scores than the pressure pain threshold.

CONCLUSIONS

The PSQ score was significantly higher in pelvic pain patients, and correlations between QSTs and the PSQ were only found for patients.

SIGNIFICANCE

The PSQ reflects pain sensitivity in women with PPP and can be used as a non-invasive and painless way to assess this condition in clinical practice.

Depression as a mediator of quality of life in patients with neuropathic pain: A cross-sectional study

AIMS

To explore whether pain intensity has an indirect effect on quality of life through mediation of depression in patients with neuropathic pain (NeP).

DESIGN

An observational, questionnaire-based, cross-sectional study.

METHODS

A convenience sample of patients suffering from NeP were enrolled from June 2015 - May 2016. Three questionnaires were used to collect data of pain intensity, Quality of life and depression. Andrew Hayes' PROCESS macro modelling tool for the SPSS software, based on the mediation Bootstrap confidence interval method, was used to analyse the mediation effect.

RESULTS

Both pain intensity and depression correlated negatively with the quality of life of patients. The indirect effect of pain intensity on the quality of life through depression was negative.

CONCLUSIONS

Increased pain intensity and depression were associated with a decreased quality of life in patients suffering from NeP and pain intensity had an indirect effect on the quality of life of patients through depression.

IMPACT

A low quality of life and depression are commonly seen in patients with NeP. However, little is known about the relationship between pain, quality of life and depression. Both pain intensity and depression had some negative effect on quality of life in patients with NeP. Pain intensity had an indirect effect on quality of life through a mediation effect of depression in patients with NeP. When caring for patients with NeP, nurses should assess depression routinely and try to alleviate it.

The use of brain functional magnetic resonance imaging to determine the mechanism of action of gabapentin in managing chronic pelvic pain in women: a pilot study

OBJECTIVE

To inform feasibility and design of a future randomised controlled trial (RCT) using brain functional MRI (fMRI) to determine the mechanism of action of gabapentin in managing chronic pelvic pain (CPP) in women.

DESIGN

Mechanistic study embedded in pilot RCT.

SETTING

University Hospital.

PARTICIPANTS

Twelve women (18-50 years) with CPP and no pelvic pathology (follow-up completed March 2014).

INTERVENTION

Oral gabapentin (300-2700 mg) or matched placebo.

OUTCOME MEASURES

After 12 weeks of treatment, participants underwent fMRI of the brain (Verio Siemens 3T MRI) during which noxious heat and punctate stimuli were delivered to the pelvis and arm. Outcome measures included pain (visual analogue scale), blood oxygen level dependent signal change and a semi-structured acceptability questionnaire at study completion prior to unblinding.

RESULTS

Full datasets were obtained for 11 participants. Following noxious heat to the abdomen, the gabapentin group (GG) had lower pain scores (Mean: 3.8 [SD 2.2]) than the placebo group (PG) (Mean: 5.8 [SD 0.9]). This was also the case for noxious heat to the arm with the GG having lower pain scores (Mean: 2.6 [SD 2.5]) than the PG (Mean: 6.2 [SD 1.1]). Seven out of 12 participants completed the acceptability questionnaire. 71% (five out of seven) described their participation in the fMRI study as positive; the remaining two rated it as a negative experience.

CONCLUSIONS

Incorporating brain fMRI in a future RCT to determine the mechanism of action of gabapentin in managing CPP in women was feasible and acceptable to most women.

TRIAL REGISTRATION NUMBER

ISRCTN70960777.