Referred Muscle Pain: Clinical and Pathophysiologic Aspects

MyofAPPcial: Construct validity of a novel technological aid for improving clinical reasoning in the management of myofascial pain syndrome

BACKGROUND

Physiotherapists encounter challenges in diagnosing myofascial trigger points (MTrPs), which are crucial for managing myofascial pain but difficult due to their complex referred pain patterns. We aimed to assess if an interactive software (MyofAPPcial) can enhance the ability of physical therapists specialized in musculoskeletal disorders (as clinicians and as researchers and educators) to identify referred pain patterns associated with specific MTrPs and to explore their opinion about incorporating this technology regularly into their professional setting.

METHODS

After developing the app, a descriptive cross-sectional survey study was conducted. Participants were asked about their demographic characteristics, professional experience, two knowledge tests (first without and later with MyofAPPcial support) and the 18-item mHealth app usability questionnaire.

RESULTS

Fifty-nine participants completed the survey (47.5% clinicians and 62.5% researchers/educators). Groups were comparable in terms of age, gender and professional experience (p > .05). However, clinicians coursed shorter specific MPS trainings (p = .007) and handle more cases a week (p < .001). In the first knowledge test, participants in both the groups were more accurate in identifying pain maps of highly prevalent MTrPs than those with a moderate or low prevalence (p < .001), with no differences between the groups for individual items (all, p > .05) nor the total score (p > .05). In the second knowledge test, perfect scores were obtained for all items in both the groups. Finally, MyofAPPcial scored high satisfaction and app usefulness, with no difference between clinicians and researchers/educators (except greater convenience of use for researchers/educators p = .02).

CONCLUSIONS

MyofAPPcial enhances physiotherapists' ability to accurately identify MTrPs, with a good acceptation among clinicians and researchers/educators.

Quantitative somatosensory testing of the abdomen: establishing initial reference values across developmental age and biological sex

ABSTRACT

Abdominal pain is a common symptom of several debilitating conditions (eg, inflammatory bowel disease, irritable bowel syndrome, and endometriosis) and affects individuals throughout their lifespan. Quantitative sensory testing (QST) reference values exist for many body sites but not the abdomen. Using a QST battery adapted from the German Research Network on Neuropathic Pain, we collected QST data on the upper and lower abdomen in 181 pain-free participants, ages 12 to 50 years, to establish reference values by age and biological sex. The normative values are presented as medians for each QST measure by sex (male, n = 63; female, n = 118) and across 3 age categories (adolescents: 12-19 years, n = 48; young adults: 20-30 years, n = 87; and adults: 31-50 years, n = 46). Evaluating the sensory functioning of the abdomen and characterizing ranges of QST measures is an essential first step in understanding and monitoring the clinical course of sensory abnormalities in patients with underlying diseases affecting the abdomen and pelvis. The impact of age and development on sensory functioning is necessary, given age-related changes in pain perception and modulation.

Referred pain: characteristics, possible mechanisms, and clinical management

Purpose of this review

Referred pain is a common but less understood symptom that originates from somatic tissues. A comprehensive recognition of referred pain is important for clinicians when dealing with it. The purpose of this study is to summarize the current understanding of referred pain, including its pathogenesis, characteristics, diagnosis, and treatment.

Recent findings

Referred pain arises not only from pathologies primarily involving local tissue but also from lesions in distant structures. Central sensitization of convergent neurons and peripheral reflexes of dichotomizing afferent fibers are two theories proposed to explain the pathological mechanism of referred pain. Because syndromes related to referred pain of different origins overlap each other, it is challenging to define referred pain and identify its originating lesions. Although various approaches have been used in the diagnosis and treatment of referred pain, including conservative treatment, blockade, radiofrequency, and surgery, management of referred pain remains a clinical challenge.

Summary

Unlike radicular pain and neuropathic pain, referred pain is a less studied area, despite being common in clinics. Referred pain can derive from various spinal structures, and blockage helps identify the primary pathology. Due to the heterogeneity of referred pain, treatment outcomes remain uncertain. Further studies are needed to improve our understanding of referred pain.

Left Lower Abdominal Pain as an Initial Symptom of Multiple Myeloma

Multiple myeloma can present with various general symptoms such as fever, fatigue, and night sweats. Bone pain can occur in the pelvic and vertebral bones. However, there are a few reports of abdominal pain as an initial symptom of multiple myeloma. Here, we report the case of a 73-year-old male patient with a chief complaint of acute left lower abdominal pain. The abdominal physical findings were unremarkable. The pain was considered as referred pain, but there was no pain in response to a knock on the back. Further investigation using enhanced abdominal CT revealed a lesion in the left vertebral arch of the 10th thoracic vertebra. Bone marrow biopsy led to a diagnosis of IgA-type multiple myeloma. This case shows that abdominal pain could indicate vertebral lesions, and even without back pain, the condition of the vertebral arches should be investigated.

Masticatory Myofascial Pain Syndrome: Implications for Endodontists

INTRODUCTION

Masticatory myofascial pain syndrome can present similarly to other dental conditions in odontogenetic structures. Endodontists should be familiar with the symptomology and pathophysiology of masticatory myofascial pain syndrome to avoid misdiagnosis, incorrect treatment, and medicolegal repercussions. The aim of this review was to provide a foundational summary for endodontists to identify and correctly manage masticatory myofascial pain syndrome.

METHODS

A narrative review of the literature was performed through a MEDLINE search and a hand search of the major myofascial pain textbooks.

RESULTS

Masticatory myofascial pain syndrome is a musculoligamentous syndrome that can present similarly to odontogenic pain or refer pain to the eyebrows, ears, temporomandibular joints, maxillary sinus, tongue, and hard palate. Currently, the most comprehensive pathophysiology theory describing masticatory myofascial pain syndrome is the expanded integrated hypothesis. The most widely accepted diagnostic guidelines for masticatory myofascial pain syndrome are the Diagnostic Criteria for Temporomandibular Disorders; however, their diagnostic capability is limited. There is no hierarchy of treatment methods because each patient requires a tailored and multidisciplinary management aimed at regaining the muscle's range of motion, deactivating the myofascial trigger points, and maintaining pain relief.

CONCLUSIONS

The pain patterns for masticatory myofascial pain syndrome are well-known; however, there is a lack of consensus on the most proper method of trigger point diagnosis or pain quantification. The diagnostic strategies for masticatory myofascial pain syndrome vary, and the diagnostic aids are not well developed.

The Radically Embodied Conscious Cybernetic Bayesian Brain: From Free Energy to Free Will and Back Again

Drawing from both enactivist and cognitivist perspectives on mind, I propose that explaining teleological phenomena may require reappraising both "Cartesian theaters" and mental homunculi in terms of embodied self-models (ESMs), understood as body maps with agentic properties, functioning as predictive-memory systems and cybernetic controllers. Quasi-homuncular ESMs are suggested to constitute a major organizing principle for neural architectures due to their initial and ongoing significance for solutions to inference problems in cognitive (and affective) development. Embodied experiences provide foundational lessons in learning curriculums in which agents explore increasingly challenging problem spaces, so answering an unresolved question in Bayesian cognitive science: what are biologically plausible mechanisms for equipping learners with sufficiently powerful inductive biases to adequately constrain inference spaces? Drawing on models from neurophysiology, psychology, and developmental robotics, I describe how embodiment provides fundamental sources of empirical priors (as reliably learnable posterior expectations). If ESMs play this kind of foundational role in cognitive development, then bidirectional linkages will be found between all sensory modalities and frontal-parietal control hierarchies, so infusing all senses with somatic-motoric properties, thereby structuring all perception by relevant affordances, so solving frame problems for embodied agents. Drawing upon the Free Energy Principle and Active Inference framework, I describe a particular mechanism for intentional action selection via consciously imagined (and explicitly represented) goal realization, where contrasts between desired and present states influence ongoing policy selection via predictive coding mechanisms and backward-chained imaginings (as self-realizing predictions). This embodied developmental legacy suggests a mechanism by which imaginings can be intentionally shaped by (internalized) partially-expressed motor acts, so providing means of agentic control for attention, working memory, imagination, and behavior. I further describe the nature(s) of mental causation and self-control, and also provide an account of readiness potentials in Libet paradigms wherein conscious intentions shape causal streams leading to enaction. Finally, I provide neurophenomenological handlings of prototypical qualia including pleasure, pain, and desire in terms of self-annihilating free energy gradients via quasi-synesthetic interoceptive active inference. In brief, this manuscript is intended to illustrate how radically embodied minds may create foundations for intelligence (as capacity for learning and inference), consciousness (as somatically-grounded self-world modeling), and will (as deployment of predictive models for enacting valued goals).

Visceral pain, mechanisms, and implications in musculoskeletal clinical practice

The global impact of visceral pain is extremely high, representing a significant portion of all forms of chronic pain. In musculoskeletal practice, at least one-third of people with persistent noncancerous pain report recurrent abdominal, pelvic, or chest pain symptoms. Visceral pain can be felt in several different areas of the body and can migrate throughout a region, even though the site of origin does not appear to change. Traditionally, clinicians have examined musculoskeletal pain through a reductionist lens that ignores the influence of the visceral system on musculoskeletal pain. The hypothesis presented is that visceral pain has an important influence on developing and maintaining different types of musculoskeletal pain through processes within the peripheral or central nervous systems, as a result of a visceral nociceptive stimulus generated by pathoanatomical or functional alterations. The hypothesis predicts that a consideration of the function of the visceral system in musculoskeletal pain conditions will improve clinical outcomes, moving beyond a linear model and adopting a more holistic approach, especially in the more complex groups of patients.

Posture and Health: Are the Biomechanical Postural Evaluation and the Postural Evaluation Questionnaire Comparable to and Predictive of the Digitized Biometrics Examination?

Background: Postural tone alterations are expressions of myofascial and, therefore, of structural, visceral, and emotional disorders. To prevent these disorders, this study proposes a quantitative investigation method which administers a postural evaluation questionnaire and a postural biomechanical evaluation to 100 healthy subjects. Methods: The reliability of the method is studied by comparing both assessments with digitized biometrics. In addition, 50 subjects undergo the biomechanical evaluation form twice, by four different operators, to study the intraoperative repeatability. Results: The results show a satisfactory overlap between the results obtained with the postural evaluation questionnaire and the postural biomechanical evaluation compared to computerized biometrics. Furthermore, intraoperative repeatability in the use of the biomechanical evaluation form is demonstrated thanks to a minimal margin of error. Conclusions: This experience suggests the importance of undertaking this path in both the curative and the preventive sphere on a large scale and on different types of people who easily, and even unknowingly, may face dysfunctional syndromes, not only structural and myofascial but also consequently of the entire body’s homeostasis.

Abnormal white matter microstructure along the thalamus fiber pathways in women with primary dysmenorrhea

Primary dysmenorrhea (PDM) is a cyclic menstrual pain in the absence of pelvic anomalies, and women with PDM have an increased sensitivity to pain than the internal and external areas associated with menstrual pain. However, the brain abnormality in the ascending pain pathways in dysmenorrhea remains largely unclear. As the thalamus plays a significant role in transmission of nociceptive input, we examined whether white matter microstructure of the thalamus-related fiber tracts obtained by DTI in women with PDM (n = 47) differs from healthy controls. A novel tractography atlas-based analysis method that detects tract integrity and altered microstructural properties along selected fibers was employed. The fiber bundles of interest contained the thalamus- primary somatosensory cortex (SI), thalamus- dorsal anterior cingulate cortex (dACC)/supplementary motor area (SMA), thalamus-insula, and thalamus-ACC. As compared with controls, abnormal white matter microstructures were found along the thalamus-related white matter fiber tracts. Additionally, the intensity of menstrual pain was significantly associated with diffusion measures of thalamus-SI fiber connections. Our study suggested that the thalamus-related pain processing pathways had altered white matter integrity that persisted beyond the time of menstruation, and the white matter microstructure of the thalamus-SI pathways was closely related to menstrual pain in the intensity by women with PDM.

Various diagnostic possibilities for zygomatic arch pain: Seven case reports and review of literature

BACKGROUND

Pain of the zygomatic arch region is common among patients with orofacial pain, especially in those with temporomandibular disorder-related pain of a myogenic origin. Since zygomatic arch pain may occur due to various causes other than muscle pain, appropriate diagnosis and treatment planning is essential to ensure its successful management. Unfortunately, zygomatic arch pain has not been handled as an independent clinical feature until now, and studies have mainly focused on pain resulting from trauma and surgical procedures.

CASE SUMMARY

We describe 7 independent cases, all of which presented with the identical chief complaint of pain in the zygomatic arch region. However, the underlying causes were different for each, being myofascial pain, myositis, tooth crack, dental caries, sinusitis, neuropathic pain, and salivary gland tumor respectively. In this case report, the clinical features of each case are investigated and diseases to be considered in the diagnostic process are suggested, along with the diagnostic modalities (including computed tomography and magnetic resonance imaging) that can lead to the appropriate final diagnosis.

CONCLUSION

Zygomatic arch pain is a common complaint encountered in the orofacial pain clinic but may lead to misdiagnosis. Clinicians must have in-depth knowledge of the possible differential diagnoses and evaluation tools.

Visceral Manipulation Decreases Pain, Increases Cervical Mobility and Electromyographic Activity of the Upper Trapezius Muscle in Non-Specific Neck Pain Subjects with Functional Dyspepsia: Two Case Reports

BACKGROUND AND PURPOSE

The lack of clear knowledge about the etiology of nonspecific neck pain (NS-NP) strengthens the need for other mechanisms, still poorly described in the literature, to be investigated. Therefore, a quantitative analysis of two cases of NS-NP in subjects with functiona dyspepsia was conducted in order to verify the immediate and seven-day postintervention effects of visceral manipulation (VM) to the stomach and liver on neck pain, cervical range of motion (ROM), and electromyographic (EMG) activity of the upper trapezius muscle.

CASE DESCRIPTION

Case A was an 18-year-old female with a complaint of nonspecific neck pain for one year, with reported pain on waking, momentary intermittent pain, and occasional symptoms of paresthesia in the upper limbs. Case B was a 25-year-old female with a complaint of cervical pain for one year, accompanied by pain in the unilateral temporomandibular joint, and medial thoracic region. Both cases presented functional dyspepsia.

OUTCOMES

The results demonstrated (subjects A and B, respectively) a general increase in cervical ROM (range: 12.5% to 44.44%) and amplitude of the EMG signal (immediately postintervention: 57.62 and 20.78; post seven days: 53.54% and 18.83%), and an increase in muscle fiber conduction velocity immediately postintervention (4.44% and 7.44%) and a decrease seven days postintervention (25.25% and 21.18%). For pain, a decrease was observed immediately postintervention (23.07% and 76.92%) and seven days postintervention (100% for both subjects).

DISCUSSION

A single VM provided important clinical improvement in neck pain, cervical spine range of motion, and EMG activity of the upper trapezius muscle, immediately and seven days postintervention in two NS-NP subjects with functional dyspepsia.

Evidence and consensus recommendations for the pharmacological management of pain in India

Despite enormous progress in the field of pain management over the recent years, pain continues to be a highly prevalent medical condition worldwide. In the developing countries, pain is often an undertreated and neglected aspect of treatment. Awareness issues and several misconceptions associated with the use of analgesics, fear of adverse events - particularly with opioids and surgical methods of analgesia - are major factors contributing to suboptimal treatment of pain. Untreated pain, as a consequence, is associated with disability, loss of income, unemployment and considerable mortality; besides contributing majorly to the economic burden on the society and the health care system in general. Available guidelines suggest that a strategic treatment approach may be helpful for physicians in managing pain in real-world settings. The aim of this manuscript is to propose treatment recommendations for the management of different types of pain, based on the available evidence. Evidence search was performed by using MEDLINE (by PubMed) and Cochrane databases. The types of articles included in this review were based on randomized control studies, case-control or cohort studies, prospective and retrospective studies, systematic reviews, meta-analyses, clinical practice guidelines and evidence-based consensus recommendations. Articles were reviewed by a multidisciplinary expert panel and recommendations were developed. A stepwise treatment algorithm-based approach based on a careful diagnosis and evaluation of the underlying disease, associated comorbidities and type/duration of pain is proposed to assist general practitioners, physicians and pain specialists in clinical decision making.

A New Perspective of Neuromyopathy to Explain Intractable Pancreatic Cancer Pains; Dry Needling as an Effective Adjunct to Neurolytic Blocks

We present a new perspective of neuromyopathy in pancreatic cancer pain (PCP) referral to bodywall; proposal of new rationale to include ultrasound guided dry needling (USGDN) of body wall muscles as an effective adjunct to neurolytic coeliac plexus block (NCPB) or splanchnic nerve radiofrequency ablation (SRF) for comprehensive interventional management. Methods: PCP response to SRF in 2 patients and NCPB in 3 patients was documented on numerical rating scale (NRS) on post procedure days 3 and 15. If the residual pain was >5 NRS on day 15, USGDN of abdominal and back muscles was started on a thrice weekly basis. The response to USGDN documented on day 30 after approximately 6 sessions of DN, showed a significant pain reduction (0-2 NRS) with 50% reduction of pre-treatment opioid consumption. This was sustained at 6 months or till their demise. Convergence of visceral and somatic nerves at the dorsal horn (viscerosomatic neurons) causes referral of visceral pain to the back and abdominal muscles. This leads to formation of myofascial trigger points (MTrPs) in the muscles which sets up a parallel network of sensitized peripheral and central motor nociceptive processing (neuromyopathy). USGDN specifically addressed the MTrPs that develop as an epiphenomenon of self-perpetuating neuromyopathy while SRF/NCPB, analgesics and neuromodulators could address only visceral nociceptive afferents (pain mediated through celiac plexus) which forms a meagre 10% of the total spinal cord afferent input. Thus, we conclude that combination of neuromyopathy and viscerosomatic convergence in PCP indicate a specific role for DN as an adjunct to SRF/NCPB in our patients

Effect of bloodletting therapy at local myofascial trigger points and acupuncture at Jiaji (EX-B 2) points on upper back myofascial pain syndrome: a randomized controlled trial

OBJECTIVE

To observe the clinical efficacy of bloodletting therapy and acupuncture at Jiaji points for treating upper back myofascial pain syndrome (MPS), and compare this with lidocaine block therapy.

METHODS

A total of 66 upper back MPS patients were randomly assigned to either the treatment group or the control group in a 1: 1 ratio. The treatment group (n = 33) were treated with bloodletting therapy at local myofascial trigger points and acupuncture at Jiaji (EX-B 2) points; one treatment course consisted of five, single 20-min-treatments with a 2-day break between each treatment. The control group (n = 33) were treated with a lidocaine block at trigger points; one treatment course consisted of five sessions of lidocaine block therapy with a 2-day break between each session. The simplified McGill Scale (SF-MPQ) and tenderness threshold determination were used to assess pain before and after a course of treatment.

RESULTS

After the third and fifth treatment, the SF-MPQ values were significantly decreased (P < 0.01) and the tenderness thresholds were significantly increased (P < 0.01) in both groups compared with before treatment. There were no significant differences in pain assessments between the two groups after three and five treatments (P > 0.05). There were five cases with minor adverse reactions reported in the control patients, while no adverse reactions were reported in the treatment group.

CONCLUSION

Bloodletting therapy at local myofascial trigger points and acupuncture at Jiaji points was effective in treating upper back MPS. Clinically, bloodletting and acupuncture therapy had the same efficacy as the lidocaine block therapy, with fewer adverse reactions.

Placebo-induced somatic sensations: a multi-modal study of three different placebo interventions

Somatic sensations induced by placebos are a frequent phenomenon whose etiology and clinical relevance remains unknown. In this study, we have evaluated the quantitative, qualitative, spatial, and temporal characteristics of placebo-induced somatic sensations in response to three different placebo interventions: (1) placebo irritant solution, (2) placebo laser stimulation, and (3) imagined laser stimulation. The quality and intensity of evoked sensations were assessed using the McGill pain questionnaire and visual analogue scales (VAS), while subjects' sensation drawings processed by a geographic information system (GIS) were used to measure their spatial characteristics. We found that all three interventions are capable of producing robust sensations most frequently described as "tingling" and "warm" that can reach consider-able spatial extent (≤ 205 mm²) and intensity (≤ 80/100 VAS). Sensations from placebo stimulation were often referred to areas remote from the stimulation site and exhibit considerable similarity with referred pain. Interestingly, there was considerable similarity of qualitative features as well as spatial patterns across subjects and placebos. However, placebo laser stimulation elicited significantly stronger and more widespread sensations than placebo irritant solution. Finally, novelty seeking, a character trait assessed by the Temperament and Character Inventory and associated with basal dopaminergic activity, was less pronounced in subjects susceptible to report placebo-induced sensations. Our study has shown that placebo-induced sensations are frequent and can reach considerable intensity and extent. As multiple somatosensory subsystems are involved despite the lack of peripheral stimulus, we propose a central etiology for this phenomenon.

Prediction of postoperative pain after gynecologic laparoscopy for nonacute pelvic pain

OBJECTIVE

The primary objectives of this study were to explore the pain experience after gynecologic laparoscopy that is performed for nonacute pain conditions and to determine whether preoperative psychologic tests and quantitative tests of sensitization can predict postoperative pain.

STUDY DESIGN

Participants included 61 women who underwent laparoscopy for nonacute pain (n = 61). A second group of 16 women who had undergone tubal ligation was included to explore whether laparoscopy induced a painful postoperative response in women without preoperative pain. Subjective tests included numeric pain scale, pain catastrophizing scale, depression scale, global assessment of change, and the McGill Pain Questionnaire Short Form. Quantitative sensory testing included abdominal cutaneous allodynia, trigger points, and reduced pain thresholds. The nonacute pain sample had 80% power to detect a difference of 0.5 standard deviation in average pain levels. Analysis included parametric and nonparametric comparisons of groups and univariate and linear regression analysis of clinically relevant variables.

RESULTS

In women who underwent tubal ligation, pain levels were low before and after the procedure. In women who underwent surgery for nonacute pain, pain levels at 6 months and all psychologic test scores were reduced significantly compared with baseline (P < .001 and P = .001, respectively). Among those women with positive results on the quantitative pain tests of sensitization at baseline, average postoperative pain was also significantly reduced (P < .001). Univariate analysis demonstrated only tests of sensitization that were correlated with change in average pain level (P = .01). Regression analysis suggested that baseline pain, catastrophizing, and the presence of cutaneous allodynia significantly predicted pain levels 6 months after surgery (P < .001).

CONCLUSION

Pain after laparoscopic surgery for nonacute painful conditions can be predicted by baseline pain, catastrophizing, and the presence of allodynia, which is a simple swab test that indicates sensitization.

The 2013 EAU guidelines on chronic pelvic pain: is management of chronic pelvic pain a habit, a philosophy, or a science? 10 years of development

CONTEXT

Progress in the science of pain has led pain specialists to move away from an organ-centred understanding of pain located in the pelvis to an understanding based on the mechanism of pain and integrating, as far as possible, psychological, social, and sexual dimensions of the problem. This change is reflected in all areas, from taxonomy through treatment. However, deciding what is adequate investigation to rule out treatable disease before moving to this way of engaging with the patient experiencing pain is a complex process, informed by pain expertise as much as by organ-based medical knowledge.

OBJECTIVE

To summarise the evolving changes in the management of patients with chronic pelvic pain by referring to the 2012 version of the European Association of Urology (EAU) guidelines on chronic pelvic pain.

EVIDENCE ACQUISITION

The working panel highlights some of the most important aspects of the management of patients with chronic pelvic pain emerging in recent years in the context of the EAU guidelines on chronic pelvic pain. The guidelines were completely updated in 2012 based on a systematic review of the literature from online databases from 1995 to 2011. According to this review, levels of evidence and grades of recommendation were added to the text. A full version of the guidelines is available at the EAU office or Web site (www.uroweb.org).

EVIDENCE SYNTHESIS

The previously mentioned issues are explored in this paper, which refers throughout to dilemmas for the physician and treatment team as well as to the need to inform and engage the patient in a collaborative empirical approach to pain relief and rehabilitation. These issues are exemplified in two case histories.

CONCLUSIONS

Chronic pelvic pain persisting after appropriate treatment requires a different approach focussing on pain. This approach integrates the medical, psychosocial, and sexual elements of care to engage the patient in a collaborative journey towards self-management.

Referred pain in right arm from abdominal wall pseudoaneurysm

Pseudoaneurysm of the abdominal wall is a possible but very rare clinical entity. It is a known complication of surgery, trauma, or arterial puncture, but it is rarely spontaneous. Even though it can usually present with a wide range of local symptoms, it can cause referred pain via spinal cord, which is cross-excited with afferent sympathetic nervous system. We report a case of right arm pain which was referred from a small abdominal pseudoaneurysm like a referred pain from gall bladder. This rare entity should be considered in the differential for pain management in case that the pain does not resolve with medication or interventional pain management.

Cotton-tipped applicator test: validity and reliability in chronic pelvic pain

OBJECTIVE

We sought to assess the concurrent validity and interrater reliability of the cotton-tipped applicator (CTA) test as a screening tool for diagnosis of cutaneous allodynia in patients with viscerally related chronic pelvic pain (CPP).

STUDY DESIGN

We performed a prospective cohort comparative observational study of referred patients to a gynecology clinic with CPP. A total of 22 females with CPP were compared to 23 pain-free controls and 12 cyclic pain patients. Participants were evaluated by 2 clinicians. The CTA test was performed to detect the appearance of pain in dermatomes of T10-L1.

RESULTS

Interrater reliability resulted in 98% agreement for the 3 study groups. CTA test showed 73% sensitivity and 100% specificity for differentiating patients with CPP from pain-free patients.

CONCLUSION

The CTA test had excellent interrater reliability and concurrent validity for diagnosis of cutaneous allodynia in CPP patients with visceral diseases versus controls.

Dry needling - peripheral and central considerations

Dry needling is a common treatment technique in orthopedic manual physical therapy. Although various dry needling approaches exist, the more common and best supported approach targets myofascial trigger points. This article aims to place trigger point dry needling within the context of pain sciences. From a pain science perspective, trigger points are constant sources of peripheral nociceptive input leading to peripheral and central sensitization. Dry needling cannot only reverse some aspects of central sensitization, it reduces local and referred pain, improves range of motion and muscle activation pattern, and alters the chemical environment of trigger points. Trigger point dry needling should be based on a thorough understanding of the scientific background of trigger points, the differences and similarities between active and latent trigger points, motor adaptation, and central sensitize application. Several outcome studies are included, as well as comments on dry needling and acupuncture.

Endometriosis and abdominal myofascial pain in adults and adolescents

Endometriosis and myofascial pain are common disorders with significant impact on quality of life. Increasingly, these conditions are being recognized as highly interconnected through processes that have been described for more than a century. This review is directed to this interconnection through a description of the relationships of endometriosis to proposed mechanisms of pain and chronic pain physiology; the clinical assessment of myofascial representations of this pain; and an approach to the management of these interconnected disorders.

Effects of exercise and physical activity on knee osteoarthritis

Exercise is one of the most discussed and controversial nonpharmacologic management strategies for osteoarthritis (OA) of the knee. Health care providers and patients share varied and often pseudoscientific beliefs regarding the effects of exercise on knee OA formulated on outdated notions of the etiology, pathophysiology, and progression of the condition. Based on the contemporary literature, regular light to moderate physical activity has both preventive and therapeutic benefits for individuals with knee OA. Exercise regimens with strong evidence of benefit include those that focus on aerobic/cardiovascular conditioning and lower extremity strength training. Health care providers should confidently incorporate exercise recommendations into clinical management and offer patients evidence-based and individually tailored exercise prescriptions to help manage the painful and often disabling symptoms of this condition.

Bedside testing for chronic pelvic pain: discriminating visceral from somatic pain

Objectives. This study was done to evaluate three bedside tests in discriminating visceral pain from somatic pain among women with chronic pelvic pain. Study Design. The study was an exploratory cross-sectional evaluation of 81 women with chronic pelvic pain of 6 or more months' duration. Tests included abdominal cutaneous allodynia (aCA), perineal cutaneous allodynia (pCA), abdominal and perineal myofascial trigger points (aMFTP) and (pMFTP), and reduced pain thresholds (RPTs). Results. Eighty-one women were recruited, and all women provided informed consent. There were 62 women with apparent visceral pain and 19 with apparent somatic sources of pain. The positive predictive values for pelvic visceral disease were aCA-93%, pCA-91%, aMFTP-93%, pMFTP-81%, and RPT-79%. The likelihood ratio (+) and 95% C.I. for the detection of visceral sources of pain were aCA-4.19 (1.46, 12.0), pCA-2.91 (1.19, 7.11), aMTRP-4.19 (1.46, 12.0), pMFTP-1.35 (0.86, 2.13), and RPT-1.14 (0.85, 1.52), respectively. Conclusions. Tests of cutaneous allodynia, myofascial trigger points, and reduced pain thresholds are easily applied and well tolerated. The tests for cutaneous allodynia appear to have the greatest likelihood of identifying a visceral source of pain compared to somatic sources of pain.

Acid-sensing ion channel 3 expression in mouse knee joint afferents and effects of carrageenan-induced arthritis

Arthritis is associated with decreases in local pH. Of the acid-sensing ion channels (ASIC), ASIC3 is most sensitive to such a pH change, abundantly expressed in dorsal root ganglion (DRG), and critical for the development of secondary hyperalgesia. The purpose of this study was to investigate the upregulation of ASIC3, using an acute arthritic pain model in mice. We examined ASIC3 expression in DRG neurons innervating the knee joint with and without carrageenan-induced arthritis by means of retrograde labeling and immunohistochemistry. We also examined the difference of DRG phenotype between ASIC3+/+ and ASIC3-/- mice. ASIC3 immunoreactivity was present in 31% of knee joint afferents and dominantly in small cells. After joint inflammation, ASIC3-immunoreactive neurons significantly increased in number by 50%. Calcitonin gene-related peptide (CGRP) increased similarly in both ASIC3+/+ and ASIC3-/- mice. Soma size distribution of ASIC3-immunoreactive neurons without CGRP expression was shifted to smaller-diameter neurons. Our results suggest that ASIC3 plays an important role in acute arthritic pain. Specifically, we propose that ASIC3 upregulation along with CGRP and phenotypic change in ASIC3-immunoreactive neurons without CGRP are responsible for the development of secondary hyperalgesia after carrageenan-induced arthritis.

PERSPECTIVE

This article shows that ASIC3 is upregulated along with CGRP in knee joint afferents and that there is a phenotypic change in ASIC3-immunoreactive nonpeptidergic neurons in an animal model of acute arthritis. Understanding the basic neurobiology after acute arthritis could lead to future new pharmacological management of arthritis.

Referred muscle pain is primarily peripheral in origin: the "barrier-dam" theory

The mechanisms leading to the frequent occurrence of referred muscle pain (RP) are largely unknown. It is possible that RP is caused by the increased sensitivity of local muscle nociceptors and/or by a central sensitisation. When deep pressure by palpation is used on a subject with smooth fibrotic lesions (myofibrosis) in a muscle, RP can originate as a hyperalgesic cutaneous area, adjacent to, or totally apart from the pressure pain locus. It is currently postulated that a chain reaction is activated implicating triggering of an ever-increasing number of afferent neurons and facilitation of the synaptic connection at the level of the spinal cord, causing more distally a distributed RP via convergent efferent pathways. The human interpretation of this phenomenon can be misleading when the tested person positions, after a few seconds, his RP distally from the site of pressure to the distally located RP area. As a result of what we have found in our experimentally induced RP probes, we hypothesize that deep pressure on a myofibrosis will, in the first place, within a few seconds, increase the nociceptive excitability of the afferent sensitive nerves from the RP area to the local spot of pressure on the muscle, which in return will, in the second place, excite the whole dependent RP area. The mechanism for referred muscle pain proposed in this article is linked to the "pre-local hyper-excitability theory" or "barrier-dam theory". The afferent sensitive peripheral nerves might be entrapped in local muscle hardenings (barrier-dam) with the consequence of the hyper-excitation of pre-local nerves between the distally referred pain area and the local muscular zone of tenderness. The primary pathogenesis of referred muscle pain is likely to be a peripheral sensitization with additionally a central modulation and not vice versa. Clinical and fundamental studies with experimentally induced RP are nevertheless needed to examine the hypothesis.

Treatment of Fibromyalgia, Myofascial Pain, and Related Disorders

Chronic muscle pain is a common complaint among patients who seek care for musculoskeletal disorders. A spectrum of clinical presentations exists, ranging from focal or regional complaints that usually represent myofascial pain syndromes to more wide spread pain that may meet criteria for a diagnosis of fibromyalgia. This article addresses the epidemiology, pathophysiology, and clinical management of myofascial pain syndrome and fibromyalgia. These conditions are challenging to treat and require physiatrists to be aware of the wide range of pharmacologic, rehabilitative,and psychosocial interventions that can be helpful.

Peripheral and central sensitization in musculoskeletal pain disorders: an experimental approach

This report provides a brief introduction to the manifestations of peripheral and central sensitization involved in musculoskeletal pain disorders. It has become increasingly evident that muscle hyperalgesia, referred pain, referred hyperalgesia, and widespread hyperalgesia play an important role in chronic musculoskeletal pain. A better understanding of the involved basic mechanisms and better methods to assess muscle pain in the clinic may provide new possibilities for designing rational therapies and for targeting the pharmacologic intervention optimally. Peripheral sensitization plays an important role for increased sensitivity of deep tissue. However, central sensitization may be equally important but less addressed. Quantitative sensory testing provides the possibility to evaluate these manifestations in a standardized way in patients with musculoskeletal pain or in healthy volunteers (eg, experimentally induced referred pain can be used to assess the potential involvement of central sensitization in musculoskeletal pain conditions). Central sensitization may play a role in the persistence, amplification, and spread of pain. Interventions should take this aspect into consideration.

Cervical myofascial pain and headache

Myofascial pain is a common cause of regional chronic pain. Myofascial trigger points can refer pain to the head and face in the cervical region, thus contributing to cervicogenic headache. When identified properly, cervical myofascial pain is a treatable component of headache management. This article reviews current literature on the pathophysiology, diagnosis, and management of cervical myofascial pain.

Focused review: myofascial pain

Myofascial pain is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The appropriate evaluation and management of myofascial pain is an important part of musculoskeletal rehabilitation of regional axial and limb pain syndromes. This article reviews the current hypotheses regarding the pathophysiology of myofascial trigger points and muscle pain. A critical evidence-based review of the pharmacologic, nonpharmacologic, alternative medicine, and exercise treatments of myofascial pain is provided, as well as future research directions. OVERALL LEARNING OBJECTIVE: To review critically the state of the art knowledge of myofascial pain, including pathophysiology and comprehensive management. Areas of future research are identified.

Tramadol/acetaminophen combination tablets for the treatment of osteoarthritis flare pain: a multicenter, outpatient, randomized, double-blind, placebo-controlled, parallel-group, add-on study

BACKGROUND

In a flare of osteoarthritis (OA) pain, increasing the dose of standard anti-inflammatory or routine analgesic drugs may not be practical because of an increased incidence of side effects. In patients achieving inadequate pain relief from traditional non-steroidal anti-inflammatory drugs (NSAIDs) or cyclooxygenase (COX)-2-selective inhibitors, it may be appropriate to add an analgesic agent with a different mechanism of action, thereby targeting multiple components of the pain pathway.

OBJECTIVE

The addition of tramadol/acetaminophen tablets to existing therapy was compared with the addition of placebo in the treatment of OA flare pain.

METHODS

This was a multicenter, outpatient, randomized, double-blind, placebo-controlled, parallel-group, add-on study. Patients received 1 or 2 tramadol/acetaminophen (37.5 mg/325 mg) tablets QID or matching placebo for 10 days in addition to ongoing NSAID or COX-2-selective inhibitor therapy. The primary outcome measures were average daily pain intensity and average daily pain relief scores from days 1 through 5.

RESULTS

Three hundred eight patients were randomized to tramadoUacetaminophen (n = 197) or placebo (n = 111) and were followed for up to 10 days. Patients had a mean (+/-SD) age of 60.1 +/- 9.87 years, and were predominantly female (71.8%) and white (87.7%). Their mean (+/- SD) pain visual analog score at baseline was 73.2 +/- 11.8 mm, and their mean pain intensity score was 2.4 +/- 0.5 (on a scale from 0 = none to 3 = severe). Average daily pain intensity and pain relief scores were significantly improved with tramadol/acetaminophen compared with placebo on the primary assessment of efficacy from days 1 through 5 (both, P < 0.001) and on the assessment of efficacy from days I through 10 (both, P < 0.001) Tramadol/acetaminophen was significantly superior to placebo on the patients' and physicians' overall assessments of medication (both, P < 0.001) and on 3 of 4 subscales (pain [P = 0.004], physical function [P = 0.013], and overall [P = 0.008]) of the Western Ontario and McMaster Universities Osteoarthritis Index Questionnaire. The most common treatment-emergent adverse events with tramadol/acetaminophen were nausea, vomiting, and dizziness. No serious adverse events were reported in the tramadol/acetaminophen group.

CONCLUSION

In this study, addition of tramadol/acetaminophen to NSAID or COX-2-selective inhibitor therapy was well tolerated and effective in the treatment of OA flare pain.