What outcome measures are commonly used for Complex Regional Pain Syndrome clinical trials? A systematic review of the literature

An update on the pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a rare and painful condition that has a wide range of triggering factors, often traumatic, and can present various clinical manifestations. The lack of knowledge about the underlying mechanisms has led to numerous treatment approaches, both conservative and surgical, which work through different mechanisms of action.

AREAS COVERED

In this review, the authors explore the key aspects of CRPS, including definition, diagnostic criteria, pitfalls, pathogenic hypotheses, and treatment strategies with a focus on pharmacotherapy. The review was based on a comprehensive search of the literature using PubMed, while also considering international guidelines for managing CRPS.

EXPERT OPINION

Based on the available evidence, pharmacological interventions appear to be effective in treating CRPS, especially when they target peripheral mechanisms, specifically nociceptive inflammatory pain, and when administered early in the course of the disease. However, there is still a lack of reliable evidence regarding the effects of drugs on central mechanisms of chronic pain in CRPS. In our expert opinion, drug therapy should be initiated as soon as possible, particularly in warm CRPS patient clusters, to prevent significant functional limitations, psychological distress, and negative impacts on individuals' social and economic well-being.

Fear of Movement in People With CRPS: A Psychometric Evaluation of the Tampa Scale-11 for Kinesiophobia

BACKGROUND

People with complex regional pain syndrome (CRPS) commonly report a fear of movement that can worsen symptoms and increase disability. The Tampa Scale of Kinesiophobia (TSK) is used to evaluate fear of movement and (re)injury, but findings have been inconsistent in different populations.

OBJECTIVE

To evaluate the psychometric properties of the Persian version of TSK-11 in individuals with upper limb CRPS. Specifically, to determine whether the factor structure aligns with the original 2-factor model, consisting of "activity avoidance" and "somatic focus."

MATERIALS AND METHODS

People with CRPS (n=142, mean age=42, 54% female) completed the TSK. The psychometric testing included internal consistency, test-retest reliability (intraclass correlation coefficient), and convergent construct validity. Confirmatory and exploratory factor analyses were performed to evaluate the structural validity.

RESULTS

The TSK-11 showed acceptable internal consistency (Cronbach alpha 0.93) and excellent test-retest reliability (intraclass correlation coefficient=0.93, 95% CI: 0.92-0.94). The Standard Error of Measurement and Minimal Detectable Change were 4.3 and 11.7, respectively. The results also demonstrated excellent criterion validity ( r =0.81). Confirmatory factor analysis demonstrated that the original 2-factor model did not fit. Exploratory factor analysis derived a 2-factor solution with different items. The factor structure accounted for 64.91% of the variance, and the internal consistency of the factors was acceptable (>0.90). Expert consensus suggested naming these 2 factors as fear avoidance and magnification and helplessness.

DISCUSSION

The TSK-11 demonstrates excellent retest reliability in people with CRPS. The original 2-factor structure was not confirmed, and a new 2-factor structure of the TSK-11 was proposed consisting of subscales for Fear Avoidance Beliefs and Magnification/Helplessness. Given the overlap between these constructs and the construct of pain catastrophizing, further study is needed to clarify both measures' content validity and relative uniqueness.

Interpretation and content validity of the items of the Hamilton inventory to evaluate outcomes in Persian-speaking patients with complex regional pain syndrome: A cognitive interview approach

BACKGROUND

The Hamilton Inventory for complex regional pain syndrome (CRPS) is a multidisciplinary assessment tool to evaluate signs and symptoms in patients with CRPS, developed in the English language.

PURPOSE

This study aims to translate and cross-culturally adapt this tool for Persian-speaking patients with CRPS. Furthermore, this study aimed to understand how 1) Persian-speaking experts and patients interpret and calibrate responses to items on the Hamilton Inventory and 2) compensatory strategies that might affect responses.

STUDY DESIGN

A cross sectional study with cognitive interview method.

METHODS

Ten health care providers and 10 patients with CRPS were interviewed using cognitive interviewing techniques (talk-aloud, semi-structured interview probes). All interviews were recorded and transcribed verbatim. A directed content analysis was done to analyze the interviews using a previously established framework.

RESULTS

Overall, the items on the Hamilton Inventory were well received by participants. Areas, where questions were unclear to some participants were recorded and categorized into five themes: Clarity and Comprehension (100%) in item 1 from the health professional tool and (65%) from the eleven items of the patient-reported tool. Perspective modifiers of culture influenced the calibrations of items "I feel my condition has negatively affected my relationships." (12%) and "My symptoms affect my comfort level with intimacy." (20%) from the patient-reported tool.

CONCLUSION

The findings of this study demonstrate that there is no need for substantive changes to the items of the Hamilton Inventory, as they tend to be understood by Persian-speaking experts and patients with CRPS.

An international study to explore the feasibility of collecting standardised outcome data for Complex Regional Pain Syndrome: recommendations for an international clinical research registry

Introduction

Complex Regional Pain Syndrome (CRPS) is a persistent pain condition with low prevalence. Multi-centre collaborative research is needed to attain sufficient sample sizes for meaningful studies. This international observational study: (1) tested the feasibility and acceptability of collecting outcome data using an agreed core measurement set (2) tested and refined an electronic data management system to collect and manage the data.

Methods

Adults with CRPS, meeting the Budapest diagnostic clinical criteria, were recruited to the study from 7 international research centres. After informed consent, a questionnaire comprising the core set outcome measures was completed: on paper at baseline (T1), and at 3 or 6 months (T2) using a paper or e-version. Participants and clinicians provided feedback on the data collection process. Clinicians completed the CRPS severity score at T1 and optionally, at T2. Ethical approval was obtained at each international centre.

Results

Ninety-eight adults were recruited (female n=66; mean age 46.6 years, range 19-89), of whom 32% chose to receive the T2 questionnaire in an electronic format. Fifty-five participants completed both T1 and T2. Eighteen participants and nine clinicians provided feedback on their data collection experience.

Conclusion

This study confirmed the questionnaire core outcome data are feasible and practicable to collect in clinical practice. The electronic data management system provided a robust means of collecting and managing the data across an international population. The findings have informed the final data collection tools and processes which will comprise the first international, clinical research registry and data bank for CRPS.

Delphi study to define core clinical outcomes for inclusion in a complex regional pain syndrome international research registry and data bank

ABSTRACT

Complex regional pain syndrome (CRPS) clinical trials have historically captured a diverse range of outcomes. A minimum set of CRPS patient-reported outcomes has been agreed for inclusion in a future CRPS international clinical research registry and data bank. This study aimed to identify a complementary set of core clinical outcomes. Clinicians and researchers from the international CRPS community informed the content of a 2-round electronic Delphi study. Participation was invited from members of the International Association for the Study of Pain CRPS Special Interest Group and the International Research Consortium for CRPS. In round 1, participants rated the relevance of 59 clinical outcomes in relation to the question "What is the clinical presentation and course of CRPS, and what factors influence it?" (1 = not relevant and 9 = highly relevant). In round 2, participants rerated each outcome in the light of the round 1 median scores. The criterion for consensus was median score ≥7, agreed by 75% of respondents. The core study team considered the feasibility of data collection of each identified outcome in agreeing final selections. Sixty respondents completed both survey rounds, with responses broadly consistent across professions. Nine outcomes met the consensus criterion. Final outcomes recommended for inclusion in the core clinical set were record of medications, presence of posttraumatic stress disorder, extent of allodynia, and skin temperature difference between limbs. Study findings provide robust recommendations for core clinical outcome data fields in the future CPRS international clinical research registry. Alongside patient-reported outcomes, these data will enable a better understanding of CRPS.

Physiotherapy for pain and disability in adults with complex regional pain syndrome (CRPS) types I and II

BACKGROUND

Complex regional pain syndrome (CRPS) is a painful and disabling condition that usually manifests in response to trauma or surgery and is associated with significant pain and disability. CRPS can be classified into two types: type I (CRPS I) in which a specific nerve lesion has not been identified and type II (CRPS II) where there is an identifiable nerve lesion. Guidelines recommend the inclusion of a variety of physiotherapy interventions as part of the multimodal treatment of people with CRPS. This is the first update of the review originally published in Issue 2, 2016.

OBJECTIVES

To determine the effectiveness of physiotherapy interventions for treating pain and disability associated with CRPS types I and II in adults.

SEARCH METHODS

For this update we searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL, PsycINFO, LILACS, PEDro, Web of Science, DARE and Health Technology Assessments from February 2015 to July 2021 without language restrictions, we searched the reference lists of included studies and we contacted an expert in the field. We also searched additional online sources for unpublished trials and trials in progress.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of physiotherapy interventions compared with placebo, no treatment, another intervention or usual care, or other physiotherapy interventions in adults with CRPS I and II. Primary outcomes were pain intensity and disability. Secondary outcomes were composite scores for CRPS symptoms, health-related quality of life (HRQoL), patient global impression of change (PGIC) scales and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened database searches for eligibility, extracted data, evaluated risk of bias and assessed the certainty of evidence using the GRADE system.

MAIN RESULTS

We included 16 new trials (600 participants) along with the 18 trials from the original review totalling 34 RCTs (1339 participants). Thirty-three trials included participants with CRPS I and one trial included participants with CRPS II. Included trials compared a diverse range of interventions including physical rehabilitation, electrotherapy modalities, cortically directed rehabilitation, electroacupuncture and exposure-based approaches. Most interventions were tested in small, single trials. Most were at high risk of bias overall (27 trials) and the remainder were at 'unclear' risk of bias (seven trials). For all comparisons and outcomes where we found evidence, we graded the certainty of the evidence as very low, downgraded due to serious study limitations, imprecision and inconsistency. Included trials rarely reported adverse effects. Physiotherapy compared with minimal care for adults with CRPS I One trial (135 participants) of multimodal physiotherapy, for which pain data were unavailable, found no between-group differences in pain intensity at 12-month follow-up. Multimodal physiotherapy demonstrated a small between-group improvement in disability at 12 months follow-up compared to an attention control (Impairment Level Sum score, 5 to 50 scale; mean difference (MD) -3.7, 95% confidence interval (CI) -7.13 to -0.27) (very low-certainty evidence). Equivalent data for pain were not available. Details regarding adverse events were not reported. Physiotherapy compared with minimal care for adults with CRPS II We did not find any trials of physiotherapy compared with minimal care for adults with CRPS II.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effects of physiotherapy interventions on pain and disability in CRPS. This conclusion is similar to our 2016 review. Large-scale, high-quality RCTs with longer-term follow-up are required to test the effectiveness of physiotherapy-based interventions for treating pain and disability in adults with CRPS I and II.

Complex Regional Pain Syndrome in Athletes: Scoping Review

Background and Objectives: Complex regional pain syndrome (CRPS) is a chronic condition characterized by disproportionate regional pain, usually affecting distal limbs, that follows trauma or surgery. Athletes may develop CRPS because of exposure to traumatic or overuse injuries. The aim of the present study is to review the available literature about CRPS type 1 in athletes. Materials and Methods: We searched two online databases (PubMed and Web of Science), selecting papers aiming at investigating CRPS type 1 (algodystrophy) in athletes. The analysis of databases was made considering original articles published until 30 June 2021, written in English. Results: Fifteen papers (12 case reports, 3 case series) were selected for a total of 20 clinical cases (15 females, 5 males), aged between 10 and 46 years (mean age 18.4 ± 9.8 standard deviation years). Patients included practiced different types of sport (soccer, athletics, gymnastics, basketball). The most involved anatomical sites were lower limbs, and time to diagnosis ranged from 2 days to 4 years. The most used treatments were pharmacological and physical therapies, but sometimes invasive approaches, as regional nerve, or lumbar sympathetic blocks, were provided. The main assessed outcomes were return to activity and pain. Conclusions: Our review suggests a higher prevalence of CRPS type 1 in younger people and in lower limbs than in general population but confirms the higher prevalence in females. However, the number of studies addressing CRPS in athletes is limited, as well as the number of involved patients, considering that only few and heterogeneous case reports were published about this topic. Moreover, the high prevalence of old studies (only 5 available studies in the last 10 years) might have influenced the choice of both assessment tools and management strategies. Despite these limitations, athletes showing disproportionate pain after sport-related injury should be promptly evaluated and treated through a multidimensional approach to avoid long-term consequences of algodystrophy.

A randomised placebo-controlled clinical trial on the efficacy of local lidocaine injections and oral citalopram for the treatment of complex regional pain syndrome

BACKGROUND

Complex regional pain syndrome (CRPS) is a neuropathic pain condition with no universally recognised treatment. The study evaluates the efficacy of a therapeutic protocol consisting of oral citalopram and lidocaine injections in patients affected by CRPS.

METHODS

Between January 2010 and December 2014, 150 consecutive patients with CRPS were enrolled in the study and randomly assigned into three groups: group one - lidocaine injection and oral citalopram; group two - lidocaine injection and oral placebo; and group three - injective and oral placebo. The Impairment Sum Score (ISS) was used to assess the severity of CRPS before, as well as at regular intervals after treatment commenced. Statistical significance (p < 0.05) was determined by paired t-tests.

RESULTS

The combined treatment proved to be more effective (ISS 47.6 to 12.6) than local anaesthetic alone (ISS 47.5 to 21.5) and to placebo (ISS 47.2 to 29.9).

CONCLUSION

This study indicates that CRPS may be managed with well-tolerated association of oral citalopram and lidocaine injections.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Prism adaptation treatment for upper-limb complex regional pain syndrome: a double-blind randomized controlled trial

ABSTRACT

Initial evidence suggested that people with complex regional pain syndrome (CRPS) have reduced attention to the affected side of their body and the surrounding space, which might be related to pain and other clinical symptoms. Three previous unblinded, uncontrolled studies showed pain relief after treatment with prism adaptation, an intervention that has been used to counter lateralised attention bias in brain-lesioned patients. To provide a robust test of its effectiveness for CRPS, we conducted a double-blind randomized controlled trial of prism adaptation for unilateral upper-limb CRPS-I. Forty-nine eligible adults with CRPS were randomized to undergo 2 weeks of twice-daily home-based prism adaptation treatment (n = 23) or sham treatment (n = 26). Outcomes were assessed in person 4 weeks before and immediately before treatment, and immediately after and 4 weeks after treatment. Long-term postal follow-ups were conducted 3 and 6 months after treatment. We examined the effects of prism adaptation vs sham treatment on current pain intensity and the CRPS symptom severity score (primary outcomes), as well as sensory, motor, and autonomic functions, self-reported psychological functioning, and experimentally tested neuropsychological functions (secondary outcomes). We found no evidence that primary or secondary outcomes differed between the prism adaptation and sham treatment groups when tested at either time point after treatment. Overall, CRPS severity significantly decreased over time for both groups, but we found no benefits of prism adaptation beyond sham treatment. Our findings do not support the efficacy of prism adaptation treatment for relieving upper-limb CRPS-I. This trial was prospectively registered (ISRCTN46828292).

Pain assessment in clinical trials: a narrative review

Pain is a symptom measured in many clinical trials. For pain as an outcome domain, trialists need to choose adequate outcome measure(s), as there are myriad outcome measures for pain to choose from. To ensure consistency and uniformity in clinical trials and systematic reviews, core outcome sets (COS) have been defined; COS includes a predefined minimal list of core outcomes that should be measured within a trial, to ensure their consistency and comparability. COS is defined via consensus procedure, which includes relevant stakeholders such as experts from a specific field and patients. Along with outcomes, outcome measures for each outcome need to be defined to make sure that the outcomes will be measured consistently and uniformly. Hereby we reviewed studies that have examined use of recommended core outcome domains and outcome measures in clinical trials that would be expected to measure pain. Despite the existence of COS and defined core outcome measures (COMs), multiple studies have shown that these are not necessarily used in clinical trials, or in the relevant systematic reviews, which further increases heterogeneity of existing evidence, hinders evidence synthesis and trial comparability, and assessment of comparative effectiveness of interventions. Trialists are encouraged to use COS and COMs when designing clinical trials. Research community is encouraged to design interventions that will help with identifying barriers for using COS and COMs and interventions to foster their uptake. Use of consistent pain outcomes and pain outcome measures is in the interest of patients, research community, healthcare workers and decision-makers. For clinical conditions for which there are no COS and COMs, efforts to design them would be beneficial.

Pain reduction by inducing sensory-motor adaptation in Complex Regional Pain Syndrome (CRPS PRISMA): protocol for a double-blind randomized controlled trial

BACKGROUND

Complex Regional Pain Syndrome (CRPS) presents as chronic, continuous pain and sensory, autonomic, and motor abnormalities affecting one or more extremities. People with CRPS can also show changes in their perception of and attention to the affected body part and sensory information in the affected side of space. Prism Adaptation (PA) is a behavioural intervention targeted at reducing attention deficits in post-stroke hemispatial neglect. PA also appears to reduce pain and other CRPS symptoms; however, these therapeutic effects have been demonstrated only in small unblinded studies. This paper describes the protocol for an ongoing double-blind, randomized, sham-controlled clinical trial that will evaluate the efficacy of PA treatment for CRPS. The secondary aims of the study are to examine the relationships between neuropsychological changes (such as spatial attention, space and body representation, and motor spatial performance) and clinical manifestations of CRPS, as well as symptom improvement.

METHODS

Forty-two participants with upper-limb CRPS type I will undergo 2 weeks of twice-daily PA treatment or sham treatment. The primary outcome measures are current pain intensity and CRPS severity score, measured immediately before and after the treatment period. Secondary outcome measures include the results of self-report questionnaires about pain, movement, symptoms interference, and body representation; clinical assessments of sensory, motor, and autonomic functions; and computer-based psychophysical tests of neuropsychological functions. Data are collected in four research visits: 4 weeks and 1 day before treatment, and 1 day and 4 weeks after the end of treatment. Additional follow-up through postal questionnaires is conducted 3 and 6 months post-treatment.

DISCUSSION

It is hypothesised that participants undergoing PA treatment, compared to those receiving sham treatment, will show greater reduction in pain and CRPS severity score, and improvements on other clinical and neuropsychological measures. Also, more pronounced neuropsychological symptoms are predicted to correlate with more severe clinical CRPS symptoms. This study will provide the first randomized double-blind evaluation of the therapeutic effects of PA that could be implemented as a rehabilitation method for CRPS, and will contribute to the understanding of how neuropsychological changes in body representation and attention pertain to the manifestation and treatment of CRPS.

TRIAL REGISTRATION

(27/03/2017): ISRCTN46828292 (ISRCTN - ISRCTN46828292: Treatment of complex regional pain syndrome (CRPS) with sensory-motor adaptation).

Mechanism-specific rehabilitation management of complex regional pain syndrome: Proposed recommendations from evidence synthesis

STUDY DESIGN

Narrative review.

INTRODUCTION

There are a variety of treatments with demonstrated effectiveness for the management of complex regional pain syndrome (CRPS). However given the variability in symptom presentation in this population, therapists may be unsure what treatments would be most effective for individual clients.

PURPOSE OF THE STUDY

To present a brief synthesis of the literature and propose a rehabilitation version of a mechanism-specific management algorithm to guide personalized treatment of CRPS.

METHODS

A systematic search of the literature was conducted to identify all randomized controlled trials, systematic reviews, and clinical practice guidelines addressing rehabilitation of CRPS. Results were reviewed independently by 2 reviewers and final selection of articles was reached by consensus, Data was extracted using standardized forms, and a single rater gave quality ratings. Both reviewers then used the extracted data to present a synthesis of the evidence categorized by the proposed mechanisms of effect.

RESULTS

A total of 111 articles were retrieved and reviewed for inclusion; 49 were selected for data extraction. A synthesis of the key recommendations was compiled into a rehabilitation-specific version of the mechanism-based management algorithm proposed by Gierthmühlen et al (2014).

CONCLUSIONS

Consideration of mechanism-appropriate rehabilitation interventions may assist therapists to select the most appropriate and effective treatments from the body of evidence supporting rehabilitation of CRPS.

A multi-centre study to explore the feasibility and acceptability of collecting data for complex regional pain syndrome clinical studies using a core measurement set: Study protocol

OBJECTIVES

This international, multicentre study will inform the final data collection tools and processes which will comprise the first international, clinical research registry for complex regional pain syndrome (CRPS). This study will: (a) test the feasibility and acceptability of collecting outcome measurement data using a patient reported, questionnaire core measurement set (COMPACT [Core Outcome Measurement set for complex regional PAin syndrome Clinical sTudies]); and (b) test and refine an electronic data management system to collect and manage the data.

METHODS

A maximum of 240 adults, meeting the Budapest diagnostic clinical criteria for CRPS type I or II, will be recruited across eight countries. The COMPACT questionnaire will be completed on two occasions: at baseline (T1) and 6 months later (T2). At T2, participants will choose to complete COMPACT using a paper or electronic version. Participants will be asked to feed back on their experience of completing COMPACT via a questionnaire. A separate questionnaire will ask clinicians to feed back their experience of data collection.

ANALYSIS

The study is not aiming to derive statistically significant data but to ascertain the practicalities of collecting data, using the COMPACT questionnaire set, across a range of different cultures and populations. At the end of the study, a single workshop will be convened to review the findings and agree the final documents and processes for the international registry.

Pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

Complex regional pain syndromes (CRPS) are rare painful conditions characterized by considerable variability in possible triggering factors, usually traumatic, and in the clinical scenario. The limited knowledge of the pathophysiological mechanisms has led to countless treatment attempts with multiple conservative and surgical options that act by different mechanisms of action.

AREAS COVERED

In this narrative review, the authors discuss key points about CRPS definitions, diagnostic criteria and pitfalls, pathophysiological hypotheses, and treatment strategies with particular reference to pharmacotherapy. The article was based on a literature search using PubMed while the available guidelines for the management of CRPS were also examined.

EXPERT OPINION

According to the quality of evidence, pharmacological interventions for CRPS seem to be more effective all the more so when they act on peripheral mechanisms, particularly on nociceptive pain, and when applied early in the disease, while reliable evidence about central mechanisms of chronic pain in CRPS is lacking. In our opinion, drug therapy should be preferred as early as possible, particularly in warm forms of CRPS to prevent significant functional limitation, psychological distress, and social and economic fallout.

Proximal myofascial pain in patients with distal complex regional pain syndrome of the upper limb

BACKGROUND

Patients suffering from complex regional pain syndrome (CRPS) endure myofascial-related pain in at least 50% of cases.

AIMS

To evaluate the association of upper limb CRPS with myofascial pain in muscles that might influence arm or hand pain, and to evaluate whether the paraspinal skin and subcutaneous layers' tenderness and allodynia are associated with CRPS.

METHODS

A case-control study comprising 20 patients presenting with upper limb CRPS, and 20 healthy controls matched for sex and age, were evaluated in the thoracic paraspinal area and myofascial trigger points (MTrPs) (infraspinatus, rhomboids, subclavius, serratus posterior superior and pectoralis minor) via a skin rolling test.

RESULTS

The prevalence of MTrPs in the affected extremity of the subjects was significantly higher than in the right limb of the controls: 45% exhibited active and latent MTrPs in the infraspinatus muscle (χ² = 11.613, p = 0.001); 60% in active and latent MTrPs in the subclavius muscle (χ² = 17.143, p < 0.001); and in the pectoralis minor muscle (χ2 = 13.786, p < 0.001). In addition, 55% of the cases exhibited active and latent MTrPs in the serratus posterior superior muscle (χ² = 15.172, p < 0.001). Significant differences between the groups in skin texture and pain levels (p = 0.01, p < 0.001, respectively) demonstrated that CRPS patients felt more pain, and their skin and subcutaneous layers were much tighter than in the healthy controls.

CONCLUSION

There is a high prevalence of MTrPs in the shoulder and upper thoracic area muscles in subjects who suffer from CRPS. We recommend adding an MTrPs evaluation to the standardized examination of these patients.

An observational study of the impact of genetic testing for pain perception in the clinical management of chronic non-cancer pain

OBJECTIVE

Pain levels are a key metric in clinical care. However, the assessment of pain is limited to basic questionnaires and physician interpretation, which yield subjective data. Genetic markers of pain sensitivity, such as single nucleotide polymorphisms in the catechol-O-methyltransferase gene, have been shown to be associated with pain perception and have been used to provide objective information about a patient's pain. The goal of this study was to determine if physician treatment adjustments based on genetic tests of pain perception resulted in improved outcomes for patients.

MATERIAL AND METHODS

A prospective, longitudinal study was conducted with 134 chronic non-cancer pain patients genotyped for pain perception-related catechol-O-methyltransferase haplotypes. Physicians were provided with patients' results and asked to document 1) their assessment of benefit of the genetic test; 2) treatment changes made based on the genetic test; and 3) patient clinical responses to changes implemented.

RESULTS

Based on genetic testing results, physicians adjusted treatment plans for 40% of patients. When medication changes were made based on genetic testing results, 72% of patients showed improvement in clinical status. When non-pharmacological actions were performed, 69% of physicians felt their patients' clinical status improved. Moreover, physicians believed the genetic test results were consistent with patient pain levels in 85% of cases.

CONCLUSIONS

These results demonstrate that providing personalized medicine with genetic information related to pain perception affected physician clinical decision-making for a substantial proportion of patients in this study, and that the availability and utilization of this information was a contributing factor in clinical improvement.

Recommendations for a first Core Outcome Measurement set for complex regional PAin syndrome Clinical sTudies (COMPACT)

Complex regional pain syndrome (CRPS) is a persistent pain condition that remains incompletely understood and challenging to treat. Historically, a wide range of different outcome measures have been used to capture the multidimensional nature of CRPS. This has been a significant limiting factor in the advancement of our understanding of the mechanisms and management of CRPS. In 2013, an international consortium of patients, clinicians, researchers, and industry representatives was established, to develop and agree on a minimum core set of standardised outcome measures for use in future CRPS clinical research, including but not limited to clinical trials within adult populations. The development of a core measurement set was informed through workshops and supplementary work, using an iterative consensus process. "What is the clinical presentation and course of CRPS, and what factors influence it?" was agreed as the most pertinent research question that our standardised set of patient-reported outcome measures should be selected to answer. The domains encompassing the key concepts necessary to answer the research question were agreed as follows: pain, disease severity, participation and physical function, emotional and psychological function, self-efficacy, catastrophizing, and patient's global impression of change. The final core measurement set included the optimum generic or condition-specific patient-reported questionnaire outcome measures, which captured the essence of each domain, and 1 clinician-reported outcome measure to capture the degree of severity of CRPS. The next step is to test the feasibility and acceptability of collecting outcome measure data using the core measurement set in the CRPS population internationally.

Complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a chronic pain condition that can occur after a minor trauma or surgery. It is a multifactorial condition with a complex cause and even more complex pathophysiology. There are disturbances and changes in the sympathetic, somatosensory and motor nervous system, resulting in severe pain and disability. Patients with CRPS can have their quality of life and functional ability greatly affected and they need appropriate and interdisciplinary interventions.

PURPOSE

This article contributes towards an up-to-date knowledge and an overall view of CRPS, which can contribute to a structured and systematic rehabilitation process for patients.

IMPLICATIONS

This Masterclass describes a functional restoration algorithm to assist therapists in the development of a treatment plan based on the available evidence and international guidelines. Early diagnosis and treatment is of great importance as patients (adults and children), can be severely affected in their functional capacity and quality of life.