Quantitative Dynamic Allodynograph-A Standardized Measure for Testing Dynamic Mechanical Allodynia in Chronic Limb Pain.

BACKGROUND: Dynamic mechanical allodynia (DMA) is both a symptom and a central sensitization sign, yet no standardized method for quantifying the DMA area has been reported. This study aimed to establish psychometric properties for Quantitative Dynamic Allodynography (QDA), a newly developed protocol measuring the DMA area as a percentage of the body surface. METHODS: Seventy-eight patients aged 18-65 diagnosed with chronic complex regional pain syndrome (CRPS) participated in this study. Test-retest reliability was conducted twice, one week apart (N = 20), and inter-rater (N = 3) reliability was conducted on 10 participants. Disease severity (CRPS Severity Score, CSS), pain intensity (VAS), and quality of life (SF-36) measures were utilized to test construct validity. RESULTS: High inter-rater reliability (intraclass correlation coefficient (ICC) = 0.96, p < 0.001) and test-retest reliability (r = 0.98, p < 0.001) were found. Furthermore, the QDA score was found to be correlated with the CSS (r = 0.47, p < 0.001), VAS (r = 0.37, p < 0.001), and the SF-36 physical health total (r = -0.47, p < 0.001) scores. CONCLUSION: The QDA is the first developed reliable and valid protocol for measuring DMA in a clinical setting and may be used as a diagnostic and prognostic measure in clinics and in research, advancing the pain precision medicine approach.

The associations between executive functions and different aspects of perceived pain, beyond the influence of depression, in rehabilitation setting.

We investigated the relations between several aspects of Perceived Pain (PP) and different measurements of Executive Functions (EFs), above the influence of depression, in the context of medical rehabilitation. Eighty-one neurologically intact patients participated in this study in their sub-acute stage of recovery. Different aspects of EFs were assessed using the Wisconsin Card Sorting Test (WCST), the Stop-Signal Test (SST) and the Digit Span Backward subtest of the WAIS-III (Span-B). Different aspects of PP were measured: Pain Disability Index (PDI), The Short-Form McGill Questionnaire (SF-MPQ) and the Pain Catastrophizing Scale (PCS). Depression symptoms were assessed using the Patient Health Questionnaire. The results indicate that irrespective of the presence of depression, mental flexibility is correlated with pain disability and pain severity (WSCT - PDI partial correlation: r = -.23; p=.047, WSCT - SF-MPQ partial correlation: r = -.31; p = .006). Response inhibition is correlated with pain disability (SST - PDI partial correlation: r = .37; p = .001). Updating was not correlated with any of the PP aspects. These results remain much the same after removing the chronic pain patients from the analyses. The present study emphasizes the multidimensional nature of the term "perceived pain", as well as the term "executive functions", and the relations between them.

Pain Catastrophizing Mediates the Association Between Mindfulness and Psychological Distress in Chronic Pain Syndrome.

AIM: Trait mindfulness has been found to be inversely associated with emotional distress such as depression and anxiety among patients suffering from pain. The current study investigated the putative mechanisms underlying these associations by examining whether pain catastrophizing mediates the association between mindfulness and psychological distress and whether this model differs in patients suffering from chronic pain compared to patients experiencing nonchronic pain in a medical rehabilitation setting. METHODS: Forty-eight patients in their subacute stage of recovery participated in the study. Seventeen participants had a diagnosis of chronic pain. Trait mindfulness was assessed using the Mindful Attention Awareness Scale, pain catastrophizing was assessed using the Pain Catastrophizing Scale, depression symptoms were assessed using the Patient Health Questionnaire, and anxiety was assessed using the Generalized Anxiety Disorder scale. Two mediation models were used, with pain catastrophizing mediating the association between mindfulness and depression and anxiety. RESULTS: Catastrophizing significantly mediated the association between trait mindfulness and depression (P < 0.05, confidence interval [CI] = -0.35, -0.05). Catastrophizing also mediated the relationship between trait mindfulness and anxiety (P < 0.05, CI = -0.34, -0.04). Two moderated mediation models were tested, in which pain catastrophizing fully mediated the relationship between trait mindfulness and depression and anxiety, but only in patients with chronic pain. CONCLUSIONS: The negative association between trait mindfulness and psychological distress may thus be partly attributed to pain catastrophizing: individuals high in trait mindfulness engage in less catastrophic thinking and therefore experience less distress. Importantly, this was only observed in the patients with chronic pain. These results further underscore the need to cope with pain catastrophizing and encourage mindfulness among patients with chronic pain.

Heart rate autonomic regulation system at rest and during paced breathing among patients with CRPS as compared to age-matched healthy controls.

OBJECTIVE: The objective of this study is to assess the autonomic nerve heart rate regulation system at rest and its immediate response to paced breathing among patients with complex regional pain syndrome (CRPS) as compared with age-matched healthy controls. DESIGN: Quasiexperimental. SETTING: Outpatient clinic. SUBJECTS: Ten patients with CRPS and 10 age- and sex-matched controls. METHODS: Participants underwent Holter ECG (NorthEast Monitoring, Inc., Maynard, MA, USA) recording during rest and biofeedback-paced breathing session. Heart rate variability (HRV), time, and frequency measures were assessed. RESULTS: HRV and time domain values were significantly lower at rest among patients with CRPS as compared with controls. A significant association was noted between pain rank and HRV frequency measures at rest and during paced breathing; although both groups reduced breathing rate significantly during paced breathing, HRV time domain parameters increased only among the control group. CONCLUSIONS: The increased heart rate and decreased HRV at rest in patients with CRPS suggest a general autonomic imbalance. The inability of the patients to increase HRV time domain values during paced breathing may suggest that these patients have sustained stress response with minimal changeability in response to slow-paced breathing stimuli.

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.

Effects of dual-channel functional electrical stimulation on gait performance in patients with hemiparesis.

The study objective was to assess the effect of functional electrical stimulation (FES) applied to the peroneal nerve and thigh muscles on gait performance in subjects with hemiparesis. Participants were 45 subjects (age 57.8 ± 14.8 years) with hemiparesis (5.37 ± 5.43 years since diagnosis) demonstrating a foot-drop and impaired knee control. Thigh stimulation was applied either to the quadriceps or hamstrings muscles, depending on the dysfunction most affecting gait. Gait was assessed during a two-minute walk test with/without stimulation and with peroneal stimulation alone. A second assessment was conducted after six weeks of daily use. The addition of thigh muscles stimulation to peroneal stimulation significantly enhanced gait velocity measures at the initial and second evaluation. Gait symmetry was enhanced by the dual-channel stimulation only at the initial evaluation, and single-limb stance percentage only at the second assessment. For example, after six weeks, the two-minute gait speed with peroneal stimulation and with the dual channel was 0.66 ± 0.30 m/sec and 0.70 ± 0.31 m/sec, respectively (P < 0.0001). In conclusion, dual-channel FES may enhance gait performance in subjects with hemiparesis more than peroneal FES alone.

Central Sensitization and Psychological State Distinguishing Complex Regional Pain Syndrome from Other Chronic Limb Pain Conditions: A Cluster Analysis Model.

Complex regional pain syndrome (CRPS) taxonomy has been updated with reported subtypes and is defined as primary pain alongside other chronic limb pain (CLP) conditions. We aimed at identifying CRPS clinical phenotypes that distinguish CRPS from other CLP conditions. Cluster analysis was carried out to classify 61 chronic CRPS and 31 CLP patients based on evoked pain (intensity of hyperalgesia and dynamic allodynia, allodynia area, and after-sensation) and psychological (depression, kinesiophobia, mental distress, and depersonalization) measures. Pro-inflammatory cytokine IL-6 and TNF-α serum levels were measured. Three cluster groups were created: 'CRPS' (78.7% CRPS; 6.5% CLP); 'CLP' (64.5% CLP; 4.9% CRPS), and 'Mixed' (16.4% CRPS; 29% CLP). The groups differed in all measures, predominantly in allodynia and hyperalgesia (p < 0.001, η² > 0.58). 'CRPS' demonstrated higher psychological and evoked pain measures vs. 'CLP'. 'Mixed' exhibited similarities to 'CRPS' in psychological profile and to 'CLP' in evoked pain measures. The serum level of TNF-αwas higher in the 'CRPS' vs. 'CLP' (p < 0.001) groups. In conclusion, pain hypersensitivity reflecting nociplastic pain mechanisms and psychological state measures created different clinical phenotypes of CRPS and possible CRPS subtypes, which distinguishes them from other CLP conditions, with the pro-inflammatory TNF-α cytokine as an additional potential biomarker.

A pilot study on the electrophysiological monitoring of patient's engagement in post-stroke physical rehabilitation.

Introduction: This study discusses the feasibility of an electrophysiological monitor for patient engagement during rehabilitation sessions. While patient engagement has a significant clinical role, it is not obvious how its real-time monitoring could be used.Objective: We designed this study to provide further support for the feasibility of such a tool based on the Brain Engagement Index (BEI), and to discuss clinical usefulness and its evaluation.Methods: The study involved 30 patients during post-stroke rehabilitation. Each patient underwent two sessions with BEI monitoring. In one session the therapist received real-time feedback from the monitor and in the other he did not. The BEI was compared to video-based evaluation of temporary functional change from the session start to its end and with a rater-based evaluation of the level of engagement evoked by the exercises in the session.Results: Irrespective of whether feedback is used, there is association between BEI and temporary functional change as well as with evaluated engagement. Furthermore, the contribution of the BEI monitor to rehabilitation may be demonstrated.Conclusions: It would be challenging to establish directly the monitor's contribution in large-scale studies. Nevertheless, it might be sufficient to demonstrate that the monitor provides important information regarding patient engagement.Implication for RehabilitationThis work presents an easy-to-use electrophysiological index for monitoring patient engagement in real-time.Enhanced engagement is of utmost importance for effective rehabilitation.The ability to identify in real-time barriers to engagement is expected to be of great contributive value.

Development and psychometric properties of the Sensory Responsiveness Questionnaire (SRQ).

PURPOSE: Individuals with Sensory Modulation Disorder (SMD) are characterized by an inability to normally grade the degree, intensity and nature of their responses to sensory input and are limited in their ability to fully participate in daily life activities, and attain optimal quality of life. Most existing diagnostic tools are intended for paediatric populations. A questionnaire that assesses the intensity of the affective-emotive responsiveness of adults to stimuli in all sensory modalities and the frequency of such responses for diagnosing adults with disorders in sensory modulation is necessary. This article describes the development and assessment of the psychometric properties of a novel instrument, the Sensory Responsiveness Questionnaire (SRQ), for this purpose (see Appendix). METHOD: The SRQ evolved through three developmental phases (Pilot, Version-I, and the most recent Version-II). Each phase comprised several studies conducted to further refine the instrument and to examine its psychometric properties with adults with Sensory Modulation Disorder versus SMD-free individuals (n=39 for the pilot version, n=399 for Version-I, and n=48 for Version-II). RESULTS: The scales of Version-II indicated high test-retest reliability, moderate criterion validity and strong significant construct validity. CONCLUSION: There is strong indication that the SRQ can be used to diagnose adults with SMD.

The Participation in Childhood Occupations Questionnaire (PICO-Q): a pilot study.

There is a need, among practitioners and researchers, for a feasible, user-friendly assessment tool that evaluates overall participation and guides intervention. This paper describes the process of construction and development of the Participation in Childhood Occupations Questionnaire (PICO-Q) and the establishment of its primary psychometric properties. The 22-item instrument measures the level, enjoyment, and frequency of performance for children's participation in daily occupations in a variety of environments. The questionnaire was completed by the mothers of 41 children between the ages of 6 and 10 years (24 children with and 17 children without sensory modulation disorder). Cronbach's alpha varied from. 86 to. 89, indicating internal consistency of items. Test-retest reliability varied from. 69 to. 86, indicating that the instrument provides a stable measurement over time. The PICO-Q was found to differentiate between children with and without participation restrictions. The PICO-Q shows initial reliability and validity and has both research and clinical application potential.

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.

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.

Sensory modulation disorder: a risk factor for participation in daily life activities.

Participation in childhood daily functional performance was examined in 78 children: 44 with sensory modulation disorder (SMD); (33 males, 11 females; mean age 7y 6mo [SD 1.20]) and 34 without SMD (18 males, 16 females; mean age 7y 8mo [SD 1.33]). Group classification was determined using two measures: the Short Sensory Profile (SSP) and the Full-form Sensory Profile. Parents completed a battery of caregiver questionnaires. Children with SMD scored significantly lower on all three participation scales than the control group. A high correlation was observed between level of activity performance of the Participation in Childhood Occupations Questionnaire (PICO-Q) and the SSP, and a moderate correlation was observed between the Enjoyment of Performance of the PICO-Q and the SSP. A low correlation was observed between Frequency of Performance of the PICO-Q and the SSP. Logistic regression indicated that all three participation scales (level of activity performance, level of enjoyment of the activity, and frequency of performance of the activity) are significantly associated with group classification, with odds ratios of 3.13, 2.05, and 1.73 respectively. These findings are the first, to our knowledge, to confirm claims of limited participation in daily activities among children with SMD. Our results have significant clinical implications and provide support for the need for practitioners and caregivers of children with SMD to facilitate participation.

Effect of telerehabilitation on mobility in people after hip surgery: a pilot feasibility study.

The goal of this study was to evaluate the effects of telerehabilitation on mobility in people following hip surgery. This feasibility pilot randomized controlled trial included a sample of 40 participants, with 22 male and 18 female patients and mean age (SD) of 67.5 (7.8) years following a surgical intervention. Participants were equally divided and randomly assigned to a telerehabilitation or control intervention group (6 weeks, 3 sessions/week). Telerehabilitation was based on video clips of common rehabilitation exercises focusing on the lower limbs. The control group received an exercise booklet. Both groups participated in physical therapy sessions, twice a week. Outcome measures included the Timed Up and Go test, 2-min walk test, 10-m walk test, sit to stand test, walking speed, and mean step length. Measurements were completed at baseline, at termination of the intervention, and at a 4-week follow-up examination. Improvements in both groups were demonstrated in all outcome measures in the postintervention evaluation. Improvements in the telerehabilitation group were greater in five of six tests compared with those achieved by the controls. The telerehabilitation group showed greater improvements in the 2-min walking test (86.1%) and walking speed (65.6%). During follow-up, the telerehabilitation group continued to improve in all outcome measures in contrast to the control group, who showed no changes in five of the six outcome measures. Telerehabilitation, a complementary treatment to standard physical therapy, generates a positive effect on mobility in people following hip surgery.

Sensory modulation dysfunction is associated with Complex Regional Pain Syndrome.

OBJECTIVE: Complex Regional Pain Syndrome (CRPS), a chronic pain condition, develops mainly after limb trauma and severely inhibits function. While early diagnosis is essential, factors for CRPS onset are elusive. Therefore, identifying those at risk is crucial. Sensory modulation dysfunction (SMD), affects the capacity to regulate responses to sensory input in a graded and adaptive manner and was found associated with hyperalgesia in otherwise healthy individuals, suggestive of altered pain processing. AIM: To test SMD as a potential risk factor for CRPS. METHODS: In this cross-sectional study, forty-four individuals with CRPS (29.9±11 years, 27 men) and 204 healthy controls (27.4±3.7 years, 105 men) completed the Sensory Responsiveness Questionnaire-Intensity Scale (SRQ-IS). A physician conducted the CRPS Severity Score (CSS), testing individuals with CRPS. RESULTS: Thirty-four percent of the individuals with CRPS and twelve percent of the healthy individuals were identified to have SMD (χ2 (1) = 11.95; p<0.001). Logistic regression modeling revealed that the risk of CRPS is 2.68 and 8.21 times higher in individuals with sensory over- and sensory under-responsiveness, respectively, compared to non-SMD individuals (p = 0.03 and p = 0.01, respectively). CONCLUSIONS: SMD, particularly sensory under-responsiveness, might serve as a potential risk factor for CRPS and therefore screening for SMD is recommended. This study provides the risk index probability clinical tool a simple evaluation to be applied by clinicians in order to identify those at risk for CRPS immediately after injury. Further research is needed.

Is there a relationship between light touch-pressure sensation and functional hand ability?

PURPOSE: To investigate and compare the level of light touch-pressure sensation as tested via the Semmes Weinstein monofilament (SWM) test with the level of functional hand ability. METHODS: Twenty-seven persons with isolated sensory deficit due to leprosy and 31 healthy controls were tested in the Occupational Therapy department of a hospital for patients with Hansen's disease. Palmar light touch thresholds were determined by SMW testing. Functional hand ability was tested via the Jebsen-Taylor Hand Function Test (JTHFT) and the Functional Dexterity Test (FDT). All participants were measured by manual muscle testing (MMT) to exclude any motor impairment. Data analysis compared sensory thresholds and level of functional hand ability between the two groups and examined the relationship between the variables. RESULTS: In the group with sensory deficit, the sensory thresholds were significantly higher than in the control group. Significant correlations were found between the sensory thresholds measured by the SWM test and the FDT and JTHFT scores, with higher correlations found for tasks entailing manipulation of small objects. CONCLUSIONS: The findings support the existence of a relationship between sensory light touch thresholds tested by the Semmes Weinstein monofilaments (SWMs) and hand function. However, the SWM test alone is not sufficient as an indicator of hand function and must therefore be supplemented with other hand function tests.

An EEG Tool for Monitoring Patient Engagement during Stroke Rehabilitation: A Feasibility Study.

OBJECTIVE: Patient engagement is of major significance in neural rehabilitation. We developed a real-time EEG marker for attention, the Brain Engagement Index (BEI). In this work we investigate the relation between the BEI and temporary functional change during a rehabilitation session. METHODS: First part: 13 unimpaired controls underwent BEI monitoring during motor exercise of varying levels of difficulty. Second part: 18 subacute stroke patients underwent standard motor rehabilitation with and without use of real-time BEI feedback regarding their level of engagement. Single-session temporary functional changes were evaluated based on videos taken before and after training on a given task. Two assessors, blinded to feedback use, assessed the change following single-session treatments. RESULTS: First part: a relation between difficulty of exercise and BEI was identified. Second part: temporary functional change was associated with BEI level regardless of the use of feedback. CONCLUSIONS: This study provides preliminary evidence that when BEI is higher, the temporary functional change induced by the treatment session is better. Further work is required to expand this preliminary study and to evaluate whether such temporary functional change can be harnessed to improve clinical outcome. CLINICAL TRIAL REGISTRATION: Registered with clinicaltrials.gov, unique identifier: NCT02603718 (retrospectively registered 10/14/2015).

Neuropsychological Markers of Suicidal Risk in the Context of Medical Rehabilitation.

While great strides have been made to advance the understanding of the neurobiology of suicidal behavior (SB), the neural and neuropsychological mechanisms associated with SB are not well understood. The purpose of the current study is to identify neurocognitive markers of SB in the context of medical rehabilitation. The performances of 39 patients at a medical rehabilitation center, aged 21-78, were examined on a series of neurocognitive executive tasks-decision-making (Iowa Gambling Task - IGT), mental flexibility (WCST), response inhibition (SST) and working memory (digit span). Self-report questionnaires were administered, for Suicidal behaviors, depression, Anxiety, and PTSD as well as perceived social support. Suicidal participants performed more poorly on the IGT. A mediation analysis presented a significant direct effect of decision making on suicidal risk (p < 0.14) as well as significant indirect effect of decision making on suicidal risk that was mediated by the depressive symptoms (95% BCa CI [-0.15, -0.018]) with a medium effect size (κ2 = 0.20, 95% BCa CI [0.067, 0.381]). Despite the complexity of relationship between decision-making and suicidal risk, these results suggest that clinicians should routinely assess decision-making abilities in adults at risk for suicide due to the fact that impaired decision-making may increase suicidal risk above and beyond that conferred by depression.

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.

A prospective, multisite, international validation of the Complex Regional Pain Syndrome Severity Score.

Clinical diagnosis of complex regional pain syndrome (CRPS) is a dichotomous (yes/no) categorization, a format necessary for clinical decision making. Such dichotomous diagnostic categories do not convey an individual's subtle gradations in the severity of the condition over time and have poor statistical power when used as an outcome measure in research. This prospective, international, multicenter study slightly modified and further evaluated the validity of the CRPS Severity Score (CSS), a continuous index of CRPS severity. Using a prospective design, medical evaluations were conducted in 156 patients with CRPS to compare changes over time in CSS scores between patients initiating a new treatment program and patients on stable treatment regimens. New vs stable categorizations were supported by greater changes in pain and function in the former. Results indicated that CSS values in the stable CRPS treatment group exhibited much less change over time relative to the new treatment group, with intraclass correlations nearly twice as large in the former. A calculated smallest real difference value revealed that a change in the CSS of ≥4.9 scale points would indicate real differences in CRPS symptomatology (with 95% confidence). Across groups, larger changes in CRPS features on the CSS over time were associated in the expected direction with greater changes in pain intensity, fatigue, social functioning, ability to engage in physical roles, and general well-being. The overall pattern of findings further supports the validity of the CSS as a measure of CRPS severity and suggests it may prove useful in clinical monitoring and outcomes research.