Reduction of Pain Sensitivity is Associated with the Response to Treatment in Women with Chronic Pelvic Pain

Effective Interventions for Idiopathic Chronic Pelvic Pain: A Systematic Review

BACKGROUND

Chronic pelvic pain (CPP) in women is a debilitating condition with symptoms that affect both medical and psychological systems, yet for those with idiopathic CPP (i.e., those without a known physiologic cause), no consensus for intervention exists.

AIM

A systematic review was conducted to identify the effectiveness of current biomedical, psychosocial, and integrative interventions for idiopathic CPP (ICPP).

METHOD

Five databases (PubMed, CINAHL, Cochrane, PsycInfo, Web of Science) were systematically searched with multiple keywords for publications from 2008-2022. Articles were coded for sample characteristics, research design, type of intervention, and intervention outcomes.

RESULTS

Nineteen studies met criteria. The majority of the interventions (14 studies) were biomedical, either invasive (e.g., injections), or non-invasive (e.g., medications). Five studies evaluated integrative interventions that combined biomedical and psychosocial components (e.g., a multimodal pain treatment center). Invasive biomedical interventions were better at relieving short-term pain and non-invasive biomedical interventions were superior for long-term pain; integrated interventions reduced both short-term and long-term pain. Integrative interventions also improved mental health, sexual health, and QOL.

CONCLUSION

Although most interventions for ICPP have been biomedical, integrative interventions showed greater outcome effectiveness, suggesting a focus on integrative interventions in the future.

Association between pelvic pain bothersomeness and pain sensitivity: A community-based cross-sectional study of young adult females in the Raine Study

OBJECTIVE

Pelvic pain has been associated with augmented nociceptive processing, but large studies controlling for multiple potential confounding factors are lacking. This study investigated the association between pelvic pain bothersomeness and pain sensitivity in young adult women, accounting for potential confounding factors.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling sample.

POPULATION

The Raine Study Gen2-22 year follow-up (n = 475).

MAIN OUTCOME MEASURES

The experience of bothersomeness related to pelvic pain was determined from a question in the Urogenital Distress Inventory short form. Pain sensitivity was measured using pressure pain and cold pain thresholds. Potential confounding factors included ethnicity, marital status, highest level of education, income, waist-hip ratio, level of activity, sleep quality, smoking, comorbidity history, C-reactive protein level, musculoskeletal pain experience and psychological distress.

RESULTS

Three hundred and sixty-two women (76.2%) reported no pelvic pain bothersomeness, 74 (15.6%) reported mild pelvic pain bothersomeness and 39 (8.2%) reported moderate-severe pelvic pain bothersomeness. After adjusting for marital status (and test site), moderate-severe pelvic pain bothersomeness was associated with a lower pressure pain threshold (i.e. greater pressure pain sensitivity) (coefficient -51.46, 95% CI -98.06 to -4.86, p = 0.030). After adjusting for smoking, moderate-severe pelvic pain bothersomeness was also associated with a higher cold pain threshold (i.e. greater cold pain sensitivity) (coefficient 4.35, 95% CI 0.90-7.79, p = 0.014).

CONCLUSIONS

This study suggests augmented nociceptive processing as a contributing factor in pelvic pain bothersomeness for some women. Thorough assessment of women who present clinically with pelvic pain should consider pain sensitivity as a potential contributing factor to their presentation.

Strength Exercise Has Different Effects on Pressure Pain Thresholds in Women with Endometriosis-Related Symptoms and Healthy Controls: A Quasi-experimental Study

OBJECTIVE

To evaluate the influence of strength exercises on remote pain sensitivity in women with endometriosis-related symptoms.

DESIGN

A quasi-experimental study.

SETTING

University Hospital, a tertiary health unit.

SUBJECTS

Twenty-one women with endometriosis-related symptoms and 21 healthy women provided written informed consent.

METHODS

The participants performed weekly exercise sessions on an extensor chair for four consecutive weeks. An electronic algometer was used to measure the pressure pain thresholds on the nondominant forearm. Heart rate and blood pressure were measured using a digital device. All measurements were taken before, immediately after, and 10 and 20 minutes after the exercise series.

RESULTS

Women with endometriosis-related symptoms had lower pain thresholds. Pressure pain thresholds increased immediately after exercise in healthy women, returning to baseline level 20 minutes after exercise. Women with endometriosis-related symptoms did not present significant pressure pain threshold alterations after exercise. However, they had a higher heart rate and systolic, diastolic, and average blood pressure than healthy women at all the timepoints. There were no consistent correlations between pressure pain thresholds and heart rate or blood pressure.

CONCLUSIONS

The strength exercise regimen used in this study increased pain thresholds in healthy women but not in women with endometriosis-related painful symptoms. The maintenance or even worsening of pain perception after exercise in women with persistent pain, such as those with endometriosis, may limit their adherence to a physical training program, which in turn could prevent them from experiencing the long-term beneficial effects of exercise.

Diagnostic delay for superficial and deep endometriosis in the United Kingdom

A Cross-sectional study was undertaken at a specialist centre in the United Kingdom investigating duration and causes of delay in the diagnosis of endometriosis. One hundred and one women completed a self-reported questionnaire containing 20 items about their psychosocial, symptoms and experiences. The statistical analysis included a Mann-Whitney U test. A p value of .05 was considered statistically significant. The Spearman's rank correlation was also calculated. Overall, there was a median delay of 8 years (Q1-Q3: 3-14) from the onset of symptoms to a diagnosis of endometriosis. Factors such as menstrual cramps in adolescence, presence of rectovaginal endometriosis, normalisation of pain and the attitudes of health professionals contributed to a delayed diagnosis (p values<.05). There was a negative correlation indicating the earlier the onset of symptoms, the greater the delay to diagnosis (Spearman's Rank Correlation Coefficient -0.63, p<.01). The results of this study highlight a considerable diagnostic delay associated with endometriosis and the need for clinician education and public awareness.Impact statementWhat is already known on this subject? The diagnostic delay of 7-9 years with endometriosis has been reported globally. In an effort to standardise surgical treatment, improve outcomes, and shorten delays specialist endometriosis centres were introduced in 2011. There has been no recent quality improvement assessment since the establishment of such centres.What do the results of this study add? This is the most recent evaluation in the United Kingdom since the introduction of specialist endometriosis centres. There is a considerable diagnostic delay associated endometriosis in the United Kingdom with a median of 8 years. The delays seem not to have improved over the last two decades. We have identified medical and psychosocial factors that may contribute to such delays. These include factors such as menstrual cramps in adolescence, presence of rectovaginal endometriosis, normalisation of pain and attitudes of health professionals contribute to a delayed diagnosis.What are the implications of these findings for clinical practice and/or further research? The results of this study, highlight the need for clinician education and public awareness to decrease the long term-morbidity and complications that result from untreated endometriosis.

Research on central sensitization of endometriosis-associated pain: a systematic review of the literature

Endometriosis-associated pain afflicts an enormous number of women who suffer from endometriosis. There is an urgent need to explore the pathogenesis of endometriosis-associated pain to identify targets for treatment of hyperalgesia. A search was conducted in PubMed, Web of Science, Embase, and the Cochrane Library using the search terms "endometriosis" AND ("pain" OR "hyperalgesia" OR "nociception" OR "allodynia") AND "central sensitization". The search was limited to articles published in English from 01/01/2008 to the present. Among the search results, 15 articles were eligible for systematic review, including 6 reviews, 6 human studies (one in the form of a conference abstract only), and 3 animal studies. The articles were classified into 4 lists to describe the mechanism of endometriosis-associated pain and synthesize different aspects of research on it. In conclusion, there is a need to explore the mechanism of endometriosis-associated pain in terms of innervation, vascularization, local inflammation, cross-correlated visceral sensitization, and central sensitization to identify the target molecules and signaling pathways of key genes and relevant biomarkers through new techniques, all with the goal of developing a more comprehensive treatment strategy for endometriosis than is currently available.

Chronic pelvic pain in an interdisciplinary setting: 1-year prospective cohort

BACKGROUND

Chronic pelvic pain affects ∼15% of women, and presents a challenging problem for gynecologists due to its complex etiology involving multiple comorbidities. Thus, an interdisciplinary approach has been proposed for chronic pelvic pain, where these multifactorial comorbidities can be addressed by different interventions at a single integrated center. Moreover, while cross-sectional studies can provide some insight into the association between these comorbidities and chronic pelvic pain severity, prospective longitudinal cohorts can identify comorbidities associated with changes in chronic pelvic pain severity over time.

OBJECTIVE

We sought to describe trends and factors associated with chronic pelvic pain severity over a 1-year prospective cohort at an interdisciplinary center, with a focus on the role of comorbidities and controlling for baseline pain, demographic factors, and treatment effects.

STUDY DESIGN

This was a prospective 1-year cohort study at an interdisciplinary tertiary referral center for pelvic pain and endometriosis, which provides minimally invasive surgery, medical management, pain education, physiotherapy, and psychological therapies. Exclusion criteria included menopause or age >50 years. Sample size was 296 (57% response rate at 1 year; 296/525). Primary outcome was chronic pelvic pain severity at 1 year on an 11-point numeric rating scale (0-10), which was categorized for ordinal regression (none-mild 0-3, moderate 4-6, severe 7-10). Secondary outcomes included functional quality of life and health utilization. Baseline comorbidities were endometriosis, irritable bowel syndrome, painful bladder syndrome, abdominal wall pain, pelvic floor myalgia, and validated questionnaires for depression, anxiety, and catastrophizing. Multivariable ordinal regression was used to identify baseline comorbidities associated with the primary outcome at 1 year.

RESULTS

Chronic pelvic pain severity decreased by a median 2 points from baseline to 1 year (6/10-4/10, P < .001). There was also an improvement in functional quality of life (42-29% on the pain subscale of the Endometriosis Health Profile-30, P < .001), and a reduction in subjects requiring a physician visit (73-36%, P < .001) or emergency visit (24-11%, P < .001) in the last 3 months. On multivariable ordinal regression for the primary outcome, chronic pelvic pain severity at 1 year was independently associated with a higher score on the Pain Catastrophizing Scale at baseline (odds ratio, 1.10; 95% confidence interval, 1.00-1.21, P = .04), controlling for baseline pain, treatment effects (surgery), age, and referral status.

CONCLUSION

Improvements in chronic pelvic pain severity, quality of life, and health care utilization were observed in a 1-year cohort in an interdisciplinary setting. Higher pain catastrophizing at baseline was associated with greater chronic pelvic pain severity at 1 year. Consideration should be given to stratifying pelvic pain patients by catastrophizing level (rumination, magnification, helplessness) in research studies and in clinical practice.