Complex regional pain syndrome: practical diagnostic and treatment guidelines, 4th edition

Role of Occupational Therapy in Pain Management

This new position statement from the American Occupational Therapy Association (AOTA) describes occupational therapy's role in pain management. AOTA asserts that occupational therapy practitioners are distinctly prepared to work independently and to contribute to interprofessional teams in the treatment of pain. Practitioners strive to ensure active engagement in meaningful occupations for clients at risk for and affected by pain.

Role of Occupational Therapy in Pain Management

The American Occupational Therapy Association (AOTA) asserts that occupational therapists and occupational therapy assistants, collectively referred to as occupational therapy practitioners (AOTA, 2020b), are distinctly prepared to work independently and to contribute to interprofessional teams in the treatment of pain. Occupational therapy practitioners work to ensure active engagement in meaningful occupations for "persons, groups, or populations (i.e., the client)" (AOTA, 2020b, p. 1) at risk for and affected by pain.

Impact of Active Physiotherapy Rehabilitation on Pain and Global and Functional Improvement 1-2 Months after Lumbar Disk Surgery: A Systematic Review and Meta-Analysis

Introduction: Lumbar disc surgery is a common procedure for patients with lower back pain associated with lumbar disc herniation. This study aims to evaluate the impact of active physiotherapeutic rehabilitation on global/functional improvement and subjective pain score reduction among patients 1–2 months following lumbar disc surgery. The outcomes of this study are to assess the impact of active physiotherapeutic rehabilitation on functional improvement and subjective improvement in pain behavior post active rehabilitation. The outcomes are measured as pain assessed using the visual analog scale, global measurement of improvement, back pain functional status, and return to work. Methods: Databases, including MEDLINE/PubMed (10 June 1996, 2022), Web of Science (10 June 1997, 2022), Scopus (15 March, 10 June 2004, 2022), CINAHL Plus (10 June 1961, 2022), and Cochrane (10 June 1993, 2022) were reviewed without any language restrictions. All studies were systematically screened; however, only randomized controlled trials were eligible against the inclusion/exclusion criteria. All statistical tests were conducted in Review Manager (RevMan) 5.4. The quality of studies was appraised using the grading of recommendations assessment, development, and evaluation (GRADE) approach and the risk-of-bias 2 (RoB 2) tool. Results: Fifteen articles were identified, enrolling a total of 2188 patients, where the majority of active rehabilitation interventions continued for 3 months. All these interventions began 1–2 months postoperatively, and quantitative findings were presented as mean scores. The subjective pain scores were significantly lower in the interventional group, with a mean difference (MD) of −7.01 (p = 0.004). The pain disability score was considerably lower in the interventional group, with an MD of −3.94 (p = 0.002). Global improvement was higher in the interventional group (OR = 1.94, p = 0.0001). Conclusions: This study presents significant improvement in all parameters concerning pain and functionality. Postoperative rehabilitation requires optimization concerning timing, duration, intensity, and associated components to benefit patients post lumbar disc surgery.

Clinical practice guidelines for the management of patients with chronic regional pain syndrome: a systematic appraisal using the AGREE II instrument

Aim: Chronic regional pain syndrome (CRPS) is a debilitating, painful condition of limbs that often arises after an injury and is associated with significant morbidity. Materials & methods: The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, used to assess the quality of clinical practice guidelines (CPGs), was used to evaluate seven CRPS management guideline. Results: Out of the seven CPGs evaluated using the AGREE II instrument, only one from Royal College of Physicians was found to have high-quality consensus guidelines for diagnosis and management of CRPS. Conclusion: Future CPGs should be backed by systematic literature searches, focus on guidelines clinical translation into clinical practice and applicability to the desired patient population.

Korean Medicine Treatment for Managing Complex Regional Pain Syndrome: Case Report

A 53-year-old male who had received surgery on his right ankle joint 10 years previously was diagnosed with Complex Regional Pain Syndrome the following year. Despite various treatments (sympathetic nerve-block medication, pain relievers, corticosteroids, nerve blocks, and transcutaneous electrical nerve stimulation) over the years there was no improvement in his symptoms. Recently the patient was admitted to a Korean medicine hospital where he received treatment (acupuncture, pharmacopuncture, and herbal treatment) and his symptoms gradually showed improvement. The patient was concurrently on psychiatric medicine, antihistamine medication, and opioids for pain (when necessary). A decrease in numeric rating scale, Oswestry disability index scores, and an increase in the Korean version of the 5-level EuroQol-5 dimension score showed symptom improvement within 36 days. This study suggests complex Korean medicine treatment for Complex Regional Pain Syndrome may result in a reduction in pain and improved quality of life.

Management of patients with neuropathic pain

Background: Neuropathic pain diseases commonly treated with pain medicine are postherpetic neuralgia (PHN), diabetic peripheral neuropathy (DPNP), complex regional pain syndrome (CRPS), and chronic pain after spinal surgery. Diagnosis and treatment of these neuropathic pain diseases is an arduous task, and there is a need to improve the understanding of these entities.Current Concepts: PHN is diagnosed when pain persists for more than 3 months after the healing of herpes zoster rashes, and this disease is commonly encountered in the elderly population. The pathophysiology of DPNP is ischemia of nerve tissue due to microvascular damage. In addition to sensory nerves, DPNP can also result in changes in motor and autonomic nerves. CRPS is a chronic intractable pain disorder, and is classified into types 1 and 2. Type 1 CRPS is diagnosed when there is no evidence of nerve damage while type 2 CRPS shows evidence of nerve damage. However, the signs and symptoms do not differ depending on the type. Chronic pain after spinal surgery is characterized by persistent back pain even after one or more spinal surgeries. This neuropathic pain occurs in the lower back or leg region.Discussion and Conclusion: The most crucial step in the management of patients with neuropathic pain is to suspect and diagnose if the pain has the characteristics of any pain-related disease. Although the etiology and pathophysiology may differ, the treatment of neuropathic pain remains the same and includes both conservative and interventional approaches. Neuropathic pain diseases often become chronic in nature, and thus, it is important to establish a treatment plan which aims at decreasing pain, improving patient’s functionality and attaining an acceptable quality of life.

Glomus Tumor of the Lower Extremity Previously Misdiagnosed as Complex Regional Pain Syndrome in Close Proximity to a Myxofibrosarcoma: A Case Report

Complex regional pain syndrome (CRPS) is a potentially devastating condition that can result in severe psychological and social morbidity. It is a diagnosis of exclusion, and other pathologic entities must be ruled out first. Glomus tumors are exquisitely painful benign vascular tumors that are most common in the hand and are rarely found in the lower extremity. Here, we present a case of a patient who developed a focus of severe anterior knee pain and tenderness a few months after a car accident that had been misdiagnosed as CRPS for 15 years. She coincidentally developed a sarcoma of her ipsilateral leg distal to this site. Magnetic resonance imaging of the sarcoma included the area of knee pain where, interestingly, it identified a separate small soft-tissue mass. A glomus tumor was diagnosed histologically in a needle biopsy specimen from this mass, which was resected along with the sarcoma. For the first time in 15 years, despite the additional sarcoma surgery, she reported relief of her pain and complete resolution of her “CRPS.”

Changes in the Brain Metabolism Associated with Central Post-Stroke Pain in Hemorrhagic Pontine Stroke: An 18F-FDG-PET Study of the Brain

Central post-stroke pain (CPSP) is an intractable neuropathic pain that can occur following central nervous system injuries. Spino-thalamo-cortical pathway damage contributes to CPSP development. However, brain regions involved in CPSP are unknown and previous studies were limited to supratentorial strokes with cortical lesion involvement. We analyzed the brain metabolism changes associated with CPSP following pontine hemorrhage. Thirty-two patients with isolated pontine hemorrhage were examined; 14 had CPSP, while 18 did not. Brain glucose metabolism was evaluated using 18F-fluorodeoxyglucose-positron emission tomography images. Additionally, regions revealing metabolic correlation with CPSP severity were analyzed. Patients with CPSP showed changes in the brain metabolism in the cerebral cortices and cerebellum. Compared with the control group, the CPSP group showed significant hypometabolism in the contralesional rostral anterior cingulum and ipsilesional primary motor cortex (Puncorrected < 0.001). However, increased brain metabolism was observed in the ipsilesional cerebellum (VI) and contralesional cerebellum (lobule VIIB) (Puncorrected < 0.001). Moreover, increased pain intensity correlated with decreased metabolism in the ipsilesional supplementary motor area and contralesional angular gyrus. This study emphasizes the role of the many different areas of the cortex that are involved in affective and cognitive processing in the development of CPSP.

Peripheral mechanisms of chronic pain

Acutely, pain serves to protect us from potentially harmful stimuli, however damage to the somatosensory system can cause maladaptive changes in neurons leading to chronic pain. Although acute pain is fairly well controlled, chronic pain remains difficult to treat. Chronic pain is primarily a neuropathic condition, but studies examining the mechanisms underlying chronic pain are now looking beyond afferent nerve lesions and exploring new receptor targets, immune cells, and the role of the autonomic nervous system in contributing chronic pain conditions. The studies outlined in this review reveal how chronic pain is not only confined to alterations in the nervous system and presents findings on new treatment targets and for this debilitating disease.

Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition

There have been some modest recent advancements in the research of Complex Regional Pain Syndrome, yet the amount and quality of the work in this complicated multifactorial disease remains low (with some notable exceptions; e.g., the recent work on the dorsal root ganglion stimulation). The semi-systematic (though in some cases narrative) approach to review is necessary so that we might treat our patients while waiting for "better research." This semi-systematic review was conducted by experts in the field, (deliberately) some of whom are promising young researchers supplemented by the experience of "elder statesman" researchers, who all mention the system they have used to examine the literature. What we found is generally low- to medium-quality research with small numbers of subjects; however, there are some recent exceptions to this. The primary reason for this paucity of research is the fact that this is a rare disease, and it is very difficult to acquire a sufficient sample size for statistical significance using traditional statistical approaches. Several larger trials have failed, probably due to using the broad general diagnostic criteria (the "Budapest" criteria) in a multifactorial/multi-mechanism disease. Responsive subsets can often be identified in these larger trials, but not sufficient to achieve statistically significant results in the general diagnostic grouping. This being the case the authors have necessarily included data from less compelling protocols, including trials such as case series and even in some instances case reports/empirical information. In the humanitarian spirit of treating our often desperate patients with this rare syndrome, without great evidence, we must take what data we can find (as in this work) and tailor a treatment regime for each patient.

Canadian surveillance study of complex regional pain syndrome in children

ABSTRACT

This study describes the minimum incidence of pediatric complex regional pain syndrome (CRPS), clinical features, and treatments recommended by pediatricians and pain clinics in Canada. Participants in the Canadian Paediatric Surveillance Program reported new cases of CRPS aged 2 to 18 years monthly and completed a detailed case reporting questionnaire from September 2017 to August 2019. Descriptive analysis was completed, and the annual incidence of CRPS by sex and age groupings was estimated. A total of 198 cases were reported to the Canadian Paediatric Surveillance Program, and 168 (84.8%) met the case definition. The minimum Canadian incidence of CRPS is estimated at 1.14/100,000 (95% confidence interval 0.93-1.35/100,000) children per year. Incidence was highest among girls 12 years and older (3.10, 95% confidence interval 2.76-3.44/100,000). The mean age of CRPS diagnosis was 12.2 years (SD = 2.4), with the mean time from symptom onset to diagnosis of 5.6 months (SD = 9.9) and no known inciting event for 19.6% of cases. Most cases had lower limb involvement (79.8%). Nonsteroidal anti-inflammatory drugs (82.7%) and acetaminophen (66.0%) were prescribed more commonly than antiepileptic drugs (52.3%) and antidepressants (32.0%). Referrals most commonly included physical therapy (83.3%) and multidisciplinary pain clinics (72.6%); a small number of patients withdrew from treatment because of pain exacerbation (5.3%). Pain education was recommended for only 65.6% of cases. Treatment variability highlights the need for empiric data to support treatment of pediatric CRPS and development of treatment consensus guidelines.

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.

Clinical and Neurophysiological Effects of Progressive Movement Imagery Training for Pathological Pain

Movement limitation is a common characteristic of chronic pain such that pain prevents the very movement and activity that is most likely to promote recovery. This is particularly the case for pathological pain states such as complex regional pain syndrome (CRPS). One clinical approach to CRPS that has growing evidence of efficacy involves progressive movement imagery training. Graded Motor Imagery (GMI) targets clinical and neurophysiological effects through a stepwise progression through implicit and explicit movement imagery training, mirror therapy and then functional tasks. Here we review experiences from over 20 years of clinical and research experience with GMI. We situate GMI in terms of its historical underpinnings, the benefits and outstanding challenges of its implementation, its potential application beyond CRPS. We then review the neuropathological targets of GMI and current thought on its effects on neurophysiological biomarkers. Perspective This article provides an overview of our experiences with graded motor imagery training over the last 20 years focussing on the treatment of CRPS. It does both cover the theoretical underpinnings for this treatment approach, biomarkers which indicate potential changes driven by GMI, and experiences for achieving optimal treatment results.

Psychological Interventions Are More Effective Than Educational Interventions at Improving Atopic Dermatitis Severity: A Systematic Review

ABSTRACT

We determined which educational and/or psychological interventions were most effective in atopic dermatitis (AD). A systematic review of published studies evaluated the effectiveness of educational and/or psychological interventions in MEDLINE, Embase, SCOPUS, LILACS, Cochrane, China National Knowledge Infrastructure, Taiwan Electronic Periodical Services, and CiNii. Two reviewers conducted title/abstract, full-text review, and data extraction. Twenty-four prospective studies were included, including 20 randomized controlled trials. Educational (4/7 studies) and combined educational and psychological (5/6 studies) interventions reduced AD severity; psychological (10/11 studies) interventions showed the greatest benefit. The most commonly studied psychological intervention was habit reversal training (8/11 studies), which was most frequently incorporated in studies that reduced AD severity (8/10 studies). The most commonly studied educational interventions were education on AD triggers (7/7 studies) and skin care (7/7 studies); they were incorporated in all studies that reduced AD severity. Different psychological and/or educational interventions successfully reduced AD severity, especially habit reversal training.

Possible complex regional pain syndrome following SARS-CoV-2 infection: Case report

SARS-CoV-2 infection has various manifestations including neurological and musculoskeletal system involvement. COVID-19 infection causes peripheral nerve lesions including small fibre neuropathy. Complex regional pain syndrome is a debilitating neurological condition manifested by predominantly pain associated with other sensory, motor, autonomic and tropic involvement. Identification and early treatment of CRPS has better prognosis. Here, we report a 21-year-old woman presented with pain, hyperalgesia, and swelling of left upper and lower limb following SARS-CoV-2 infection managed as possible complex regional pain syndrome.

Balloon Kyphoplasty vs Vertebroplasty: A Systematic Review of Height Restoration in Osteoporotic Vertebral Compression Fractures

Purpose of Review

This systematic review comprehensively compared balloon kyphoplasty and vertebroplasty with respect to height restoration and pain relief.

Recent Findings

PRISMA guidelines were utilized to compare balloon kyphoplasty and vertebroplasty, focusing on the primary outcome of height restoration and the secondary outcomes of pain relief and functionality. A total of 33 randomized controlled trials were included; 20 reviewed balloon kyphoplasty, 7 reviewed vertebroplasty, and 6 compared vertebroplasty to balloon kyphoplasty. Both treatments restored some vertebral body height and showed benefits in pain reduction and improved patient-reported functionality.

Summary

Balloon kyphoplasty and vertebroplasty are effective treatments for vertebral compression fractures and this review suggests that balloon kyphoplasty may be favored for vertebral height restoration. Further studies are needed to conclude whether balloon kyphoplasty or vertebroplasty is superior for alleviating pain.

[First Experiences with peripheral Nerve Stimulation using an implantable System as a Treatment Method for the Complex Regional Pain Syndrome CRPS 2]

INTRODUCTION

Peripheral nerve stimulation (PNS), based on central nerve stimulation (Spinal Cord Stimulation - SCS), has proven to be a suitable therapy option for the treatment of complex regional pain syndrome (CRPS), especially in the area of the upper extremities. However, the evidence on PNS in the current literature is very scarce.

MATERIAL AND METHODS

11 patients suffering from CRPS 2 were selected for implantation of a peripheral nerve stimulation system according to strict selection criteria. There were 5 men and 6 women with a mean age of 46.4 (24-58) years. Preoperatively, the mean pain score quoted by the patients was 8.0 (±1.3) on the ten-part numeric rating scale (NRS). In 8 patients, electrodes were implanted in the upper extremity (brachial plexus), in 2 patients in the area of the lower extremity (sciatic nerve) and in one patient on both the upper and lower extremities. The 8 active electrode poles were implanted as parallel as possible on the target nerves and connected to an external stimulation device by means of extension electrodes. After a test phase of 5 days, with positive feedback by the patients and a pain reduction of at least 4 points on the NRS, objectified by a pain log kept by the patient, the definitive impulse generator was implanted.

RESULTS

All 11 patients were successfully supplied with an implantable peripheral nerve stimulation system from Boston Scientific Inc. The mean pain reduction was 4.6 (±1.2) points on the NRS. The mean pain score postoperatively was 3.4 (±0.9). The postoperative course was uncomplicated in all patients.

CONCLUSION

Peripheral nerve stimulation appears to be a suitable therapy option for the treatment of CRPS 2 when conservative and conventional surgical treatment methods have failed. The experience with our patients shows that neuropathic pain could be successfully reduced by an average of about 4 points on the NRS. Arthrogenous symptoms, on the other hand, were not influenced by the PNS. Since CRPS is a psychosomatic illness, the integration of PNS into a multimodal therapy concept with physiotherapy and occupational therapy and psychology is essential for the success of the treatment.

From a Symptom-Based to a Mechanism-Based Pharmacotherapeutic Treatment in Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a debilitating painful condition of a distal extremity that can develop after tissue damage. CRPS is thought to be a multimechanism syndrome and ideally the most prominent mechanism(s) should be targeted by drugs in an individually tailored manner. This review gives an overview of the action and evidence of current and future pharmacotherapeutic options for CRPS. The available options are grouped in four categories by their therapeutic actions on the CRPS mechanisms, i.e. inflammation, central sensitisation, vasomotor disturbances and motor disturbances. More knowledge about the underlying mechanisms of CRPS helps to specifically target important CRPS mechanisms. In the future, objective biomarkers could potentially aid in selecting appropriate mechanism-based drugs in order to increase the effectiveness of CRPS treatment. Using this approach, current and future pharmacotherapeutic options for CRPS should be studied in multicentre trials to prove their efficacy. The ultimate goal is to shift the symptom-based selection of therapy into a mechanism-based selection of therapy in CRPS.

Correlation Between Temperature Rise after Sympathetic Block and Pain Relief in Patients with Complex Regional Pain Syndrome

OBJECTIVE

Determine the correlation between post-sympathetic block pain temperature change, and immediate and intermediate-term pain relief.

DESIGN

Retrospective analysis.

SETTING

Academic setting.

SUBJECTS

79 pts with CRPS who underwent sympathetic block.

METHODS

Pre- and post-block temperatures in the affected extremity, and pain scores immediately (based on 6-hour pain diary) post-block and at the intermediate-term 4-8-week follow-up were recorded. Post-block pain reductions of 30-49% and ≥ 50% were designated as partially sympathetically-maintained pain (SMP) and SMP. A decrease in pain score ≥ 2-points lasting ≥ 4 weeks was considered a positive intermediate-term outcome for sympathetic block.

RESULTS

A weak correlation was found between immediate-term pain relief and the extent of temperature rise for the cohort (R = 0.192, P = 0.043). Greater immediate-term pain reduction was reported among patients who experienced ≥ 7.5° C temperature increase (mean 4.1, 95% CI [3.33, 4.76]) compared to those who experienced < 2° C (2.3, 95% CI [1.36, 3.31]) and ≥ 2° C x < 7.5° C (2.9, 95% CI [1.8; 3.9]; P = 0.036). The correlations between temperature increase and intermediate-term pain score reduction at 4-8 weeks (R = 0.052, P = 0.329), and between immediate and intermediate-term pain relief (R = 0.139, P = 0.119) were not statistically significant.

CONCLUSIONS

A weak correlation was found for those who experienced greater temperature increases post-block to experience greater immediate pain relief. Higher temperature increase cutoffs than are typically used may be necessary to determine whether a patient with CRPS has SMP.

Effectiveness of pulsed electromagnetic field therapy in the management of complex regional pain syndrome type 1: A randomized-controlled trial

Objectives: This study aims to investigate whether pulsed electromagnetic field (PEMF) therapy in addition to a conventional rehabilitation program is effective on pain and functioning in patients with type 1 complex regional pain syndrome (CRPS-1) of the hand.

Patients and methods: Between March 2013 and January 2015, a total of 32 patients (16 males, 16 females; mean age: 50.1±13.1 years; range, 25 to 75 years) were included. The patients were randomly allocated into two groups. The control group (n=16) received a conventional rehabilitation program consisting of physical modalities, exercises, and occupational therapy, whereas the PEMF group (n=16) received additional PEMF (8 Hz, 3.2 mT) to the affected hand. The primary outcome measure was pain intensity using the Numeric Rating Scale (NRS). Secondary outcome measures were grip and pinch strength, hand edema, hand dexterity, and hand activities. All patients received 20 therapy sessions (five sessions/week, four weeks in total) and were evaluated before and after the therapy and at the first-month follow-up.

Results: Both groups showed significant improvements in primary and secondary outcomes (p<0.05) after the therapy and at follow-up. When the groups were compared in terms of improvements in assessment parameters, no statistically significant difference was found between the two groups in any of the outcomes (p>0.05).

Conclusion: The PEMF in addition to conventional rehabilitation program did not provide additional benefit for pain and hand functions in CRPS-1. Future studies using different application parameters such as frequency, intensity, duration, and route may provide a better understanding of the role of PEMF in CRPS-1 treatment.

Senso-Immunologic Prospects for Complex Regional Pain Syndrome Treatment

Complex regional pain syndrome (CRPS) is a chronic pain syndrome that occurs in tissue injuries as the result of surgery, trauma, or ischemia. The clinical features of this severely painful condition include redness and swelling of the affected skin. Intriguingly, it was recently suggested that transient receptor potential ankyrin 1 (TRPA1) is involved in chronic post-ischemia pain, a CRPS model. TRPA1 is a non-selective cation channel expressed in calcitonin gene-related peptide (CGRP)-positive primary nociceptors that becomes highly activated in ischemic conditions, leading to the generation of pain. In this review, we summarize the history of TRPA1 and its involvement in pain sensation, inflammation, and CRPS. Furthermore, bone atrophy is also thought to be a characteristic clinical sign of CRPS. The altered bone microstructure of CRPS patients is thought to be caused by aggravated bone resorption via enhanced osteoclast differentiation and activation. Although TRPA1 could be a target for pain treatment in CRPS patients, we also discuss the paradoxical situation in this review. Nociceptor activation decreases the risk of bone destruction via CGRP secretion from free nerve endings. Thus, TRPA1 inhibition could cause severe bone atrophy. However, the suitable therapeutic strategy is controversial because the pathologic mechanisms of bone atrophy in CRPS are unclear. Therefore, we propose focusing on the remission of abnormal bone turnover observed in CRPS using a recently developed concept: senso-immunology.

Evaluating the Relationship Between Myofascial Pain Syndrome (MPS) and Physical and Mental Health Status in Patients with Stroke

Background: Myofascial pain syndrome (MPS) is a non-inflammatory disorder with muscle stiffness and pain that occurs with the appearance of palpable and irritating nodules in the muscular system. Stroke is one of the most common neurological diseases that in many cases leads to disability and reduction of quality of life (QOL). Objectives: This study aimed to evaluate the relationship between MPS and physical and mental health (MH) status in patients with stroke. Methods: Using available sampling method, this case-control study included 260 patients with stroke. To collect data, demographic characteristics, Visual Analogue Scale (VAS), 36-item Short Form Survey (SF-36), and Depression, Anxiety and Stress Scale (DASS-21) were used. Data analysis was performed using SPSS 16. Mean and standard deviation were used for descriptive statistics and independent t-test, paired t-test, and analysis of variance (ANOVA) were used for inferential tests. Results: While the pain score was 6.35 (1.39), QOL score was 38.86 (11.69), and MH score was 16.26 (2.75) in the intervention group, these scores were 2.15 (0.96), 63.96 (17.52), and 9.02 (4.63), respectively, in the control group. The results showed no statistically significant relationship between MPS and QOL. But there was a statistically significant relationship between MPS and MH, so that the MH status of patients with MPS was lower than the MH status of other patients. Conclusions: Necessary interventions have been done to improve the health status of patients with MPS, which will lead to an increase in the health status of these patients.

"I Don't Identify with It": A Qualitative Analysis of People's Experiences of Living with Complex Regional Pain Styndrome

OBJECTIVE

Complex regional pain syndrome (CRPS) is a painful limb condition known to cause significant disability and distress. However, little previous research has explored CRPS from a patient perspective. The present qualitative study aimed to describe the experiences of people living with CRPS.

SUBJECTS

Forty-eight people with CRPS participated in this research.

METHODS

Participants completed a face-to-face or telephone interview about their perceptions and experiences of CRPS and completed three drawings to illustrate their experiences. Data were analyzed through reflexive thematic analysis, and images in drawings were grouped and coded by theme.

RESULTS

Three overarching themes encapsulated the data, including that 1) people experience CRPS as a source of severe symptoms and emotional difficulties, 2) CRPS undermines personal and social identity, and 3) this results in psychological responses that protect against the emotional and social impact of severe symptoms. Psychological responses include: a) searching for an explanation, b) "nothing is my fault," emphasizing a lack of personal responsibility and personal control, and c) detaching the limb from the self.

CONCLUSIONS

CRPS is experienced as highly threatening to physical ability, psychological state, and identity. In response to these threats, people may develop their own explanations for CRPS and may mentally detach themselves from responsibility, control, and the painful limb itself. Future research could explore the impact of these factors on psychological well-being and CRPS symptoms and outcomes.

Determinants of Diagnostic Delay in Complex Regional Pain Syndrome Type 1: An Observational Study of 180 Consecutive New Cases

BACKGROUND/OBJECTIVE

Complex regional pain syndrome type 1 (CRPS-1) is a disabling painful disease, with variable outcomes in terms of chronic pain and disability. A long time between onset and diagnosis seems predictive for late recovery and progression toward a chronic disease. This study aims to investigate demographic and clinical variables associated with delayed CRPS-1 diagnosis.

METHODS

From March 2013 to January 2018, consecutive patients newly diagnosed according to International Association for the Study of Pain diagnostic criteria for CRPS-1 were recruited. Demographic and clinical variables were collected at diagnosis. Student t test and Mann-Whitney U test were used for comparisons; Cox proportional hazards model was applied to evaluate the variables associated with delayed CRPS-1 diagnosis.

RESULTS

One hundred eighty patients entered the study. At diagnosis, women were older, and foot was more often involved than hand. The triggering event was more commonly a trauma without fracture for foot disease and a fracture for hand localization. No differences between hand and foot disease were found by the International Association for the Study of Pain diagnostic categories (clinical vs research) or pain measures. Variables significantly associated with a longer time between disease onset and diagnosis were foot localization, general practitioner referral, higher number of visits before CRPS diagnosis, and prior physiotherapy prescribed for symptoms later diagnosed as CRPS. An overt clinical manifestation (research CRPS-1) predicted a shorter delay.

CONCLUSIONS

Foot localization, prior physiotherapy prescribed for symptoms later diagnosed as CRPS, and a disease without overt clinical manifestations were independent predictive factors for a delayed diagnosis. Clinicians should pay attention to these issues to ensure a timely diagnosis and possibly avoid progression toward a chronic disease.

A descriptive study on the treatment of pediatric CRPS in the Nordic countries and Germany

Pediatric complex regional pain syndrome (pCRPS) is a rare, painful state that often occurs as a complication following physical trauma. Diagnosis and treatment require specialist expertise in a multidisciplinary setting. Treatment is focused on pain reduction and improvement in function, which differs from the treatment of adult CRPS. We performed a cross‐sectional survey with the aim of identifying pain centers in the Nordic countries and Germany that specialized in treating children with pain, especially pCRPS, and sought to describe their treatment strategies. Centers and health‐care professionals working with children experiencing chronic pain were identified using internet search engines, phones, or e‐mail. A standardized set of questions and an electronic questionnaire were answered by the participants. A total of 28 participants were identified in 24 centers, which were involved with patients having pCRPS (Germany: 7, Norway: 7, Sweden: 5, Finland: 5, Denmark: 3, and Island: 1). One center in Germany treated more than 20 patients per year. Half of the identified centers (n = 12) treated between 1 and 5 children with pCRPS per year. Guidelines for treating pCRPS were reportedly followed by 9/28 responders (32%), and physiotherapy was reported to be part of the treatment routine in most centers (74%). Interventional anesthesia was rarely used. Psychological therapy: 57% answered that it was always offered, 30% replied that it was proffered in most cases, and 13% responded that it was recommended in only a few patients. Pharmacological treatments were not commonly used. Treatment resources for pCRPS are scarce in the Nordic countries and Germany. Most centers treated very few children with pCRPS and did not have established guidelines. A multidisciplinary approach was used by many centers, most often combining physiotherapy and psychotherapy, and less commonly pharmacological treatment. The difficulties in diagnosing pCRPS and finding official referral units are unfortunate, considering the potentially favorable outcome with adequate treatment.

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.

A Meta-Analysis and Meta-Regression of Frequency and Risk Factors for Poststroke Complex Regional Pain Syndrome

Background and Objectives: This article aimed to investigate the risk factors for poststroke complex regional pain syndrome (CRPS). Materials and Methods: We searched electronic databases including PubMed, Medline, Web of Science, Cochrane Library, and Embase up to 27 October 2021. We enrolled analytical epidemiological studies comprising cohort, case-control, and cross-sectional studies. A quality assessment was performed using the Newcastle–Ottawa Quality Assessment Scale for cohort and case-control studies and the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Binary outcomes were reported as odds ratios (ORs), and continuous outcomes were described as standardized mean differences (SMDs) with 95% confidence intervals. For the meta-regression, beta coefficient and p value were adopted. Results: We included 21 articles comprising 2225 participants. Individuals with shoulder subluxation and spasticity were found to have higher risks for poststroke CRPS. Spasticity with higher modified Ashworth scale score, lower Brunnstrom hand stage, and inferior Barthel index scores were observed in patients with poststroke CRPS. The pooled incidence proportion in nine articles was 31.7%, and a correlation was found between effect sizes and the ratio of women and the proportion of left hemiparesis. The summarized prevalence in nine cross-sectional studies was 33.1%, and a correlation was observed between prevalence and the subluxation ratio and Brunnstrom stage. Conclusions: Based on our meta-analysis, being female, left hemiparesis, shoulder subluxation, spasticity, a lower Brunnstrom stage of distal upper limb, and an inferior Barthel index are all features for poststroke CRPS. Larger studies with greater statistical power may confirm our findings and clarify some other unknown risk factors for poststroke CRPS.

Improved symptoms of complex regional pain syndrome after novel lymphatic treatment and interdisciplinary pain management

INTRODUCTION

Complex regional pain syndrome (CRPS) is a pain syndrome with no singular mechanism and no specific cure. The aim of this case report is to study the impact of Lymphatic Enhancement Technology (LET) treatment on CRPS-related symptoms.

METHODS

A 51 year-old female presented with a chief complaint of severe, refractory ankle pain and CRPS related to a tibial and fibular fracture sustained three years earlier. The patient completed twelve cognitive behavioral therapy sessions over a 4-week period, and eleven physical therapy sessions over a four-month period, six of which utilized LET.

RESULTS

Pain and swelling were largely unchanged with interdisciplinary treatment before the introduction of LET. A within-session change of 37.5% in pain intensity and 87.5% in ankle girth was observed immediately after the first application of LET. Three months after beginning LET treatment, the patient maintained a 43.8% improvement in pain intensity and 100% improvement in measurements of lower extremity girth and ankle range of motion. No side effects or adverse events were associated with the LET treatment.

CONCLUSION

Swelling, pain, and mobility loss are common symptoms and features of CRPS. LET is a novel, non-invasive treatment that appears to be quite safe and effective for improving pain, swelling, and mobility loss related to CRPS.

Skin Temperature Assessment During Lumbar Sympathetic Blocks by Infrared Thermography

Complex Regional Pain Syndrome (CRPS) is a pain disorder that can be triggered by injuries or surgery affecting most often limbs. Its multifaceted pathophysiology makes its diagnosis and treatment a challenging work. To reduce pain, patients diagnosed with CRPS commonly undergo sympathetic blocks which involves the injection of a local anesthetic drug around the nerves. Currently, this procedure is guided by fluoroscopy which occasionally is considered as little accurate. For this reason, the use of infrared thermography as a technique of support has been considered.In this work, thermal images of feet soles in patients with lower limbs CRPS undergoing lumbar sympathetic blocks were recorded and evaluated. The images were analyzed by means of a computer-aided intuitive software tool developed using MATLAB. This tool provides the possibility of editing regions of interest, extracting the most important information of these regions and exporting the results data to an Excel file.Clinical Relevance- The final purpose of this work is to value the potential of infrared thermography and the analysis of its images as an intraoperatory technique of support in lumbar sympathetic blocks in patients with lower limbs CRPS.

Effect of the relative position of electrode and stellate ganglion during thermal radiofrequency ablation: a simulation study

PURPOSE

Stellate ganglion (SG) block by thermal radiofrequency ablation (RFA) is frequently conducted as a therapeutic intervention for sympathetic-maintained and neuropathic pain syndromes. RFA's partial lack of effectiveness could be partly due to the ablation zone (AZ) not completely covering the SG section and therefore preventing the 'cutting' of the afferent pathways. Our objective was to build a theoretical model to conduct computer simulations to assess the effect of the electrode position relative to the SG.

METHODS

A three-dimensional model was built including the SG and adjacent tissues (vertebrae C7-T1-T2, trachea, carotid artery and vertebral artery). RFA (90-s, 80 °C) was simulated considering a 22 G-5 mm electrode. The AZ was computed using the 50 °C isotherm.

RESULTS

An electrode displacement of 2 mm in any direction from the optimal position (centered on the SG) meant that the AZ did not fully cover the SG section. Likewise, SG size considerably affected the RFA effectiveness since the AZ fully covered the section of small but not large SGs.

CONCLUSIONS

The findings suggest that the currently used SG RFA settings (i.e., 22 G-5 mm electrode, 90-s, 80 °C) may not be appropriate due to their inability to achieve an AZ that fully covers the SG cross section under certain circumstances, such as a large SG and non-optimal positioning of the RF electrode with respect to the SG center.

Graded motor imagery modifies movement pain, cortical excitability and sensorimotor function in complex regional pain syndrome

Patients with complex regional pain syndrome suffer from chronic neuropathic pain and also show a decrease in sensorimotor performance associated with characteristic central and peripheral neural system parameters. In the brain imaging domain, these comprise altered functional sensorimotor representation for the affected hand side. With regard to neurophysiology, a decrease in intracortical inhibition for the sensorimotor cortex contralateral to the affected hand has been repetitively verified, which might be related to increased primary somatosensory cortex functional activation for the affected limb. Rare longitudinal intervention studies in randomized controlled trials have demonstrated that a decrease in primary somatosensory cortex functional MRI activation coincided with pain relief and recovery in sensorimotor performance. By applying a randomized wait-list control crossover study design, we tested possible associations of clinical, imaging and neurophysiology parameters in 21 patients with complex regional pain syndrome in the chronic stage (>6 months). In more detail, we applied graded motor imagery over 6 weeks to relieve movement pain of the affected upper limb. First, baseline parameters were tested between the affected and the non-affected upper limb side and age-matched healthy controls. Second, longitudinal changes in clinical and testing parameters were associated with neurophysiological and imaging parameters. During baseline short intracortical inhibition, as assessed with transcranial magnetic stimulation, was decreased only for hand muscles of the affected hand side. During movement of the affected limb, primary somatosensory cortex functional MRI activation was increased. Hand representation area size for somatosensory stimulation in functional MRI was smaller on the affected side with longer disease duration. Graded motor imagery intervention but not waiting, resulted in a decrease of movement pain. An increase of somatosensory hand representation size over graded motor imagery intervention was related to movement pain relief. Over graded motor imagery intervention, pathological parameters like the increased primary somatosensory cortex activation during fist movement or decreased short intracortical inhibition were modified in the same way as movement pain and hand performance improved. No such changes were observed during the waiting period. Overall, we demonstrated characteristic changes in clinical, behaviour and neuropathology parameters applying graded motor imagery in patients with upper limb complex regional pain syndrome, which casts light on the effects of graded motor imagery intervention on biomarkers for chronic neuropathic pain.

The Utility of Dynamic Movement Orthoses in the Management of Complex Regional Pain Syndrome-A Case Series

Complex regional pain syndrome (CRPS) is a relatively rare, but debilitating condition that may occur after limb or peripheral nerve trauma. Typical symptoms of CRPS include swelling, allodynia, hyperalgesia, and skin temperature changes. Although a variety of pharmacological and non-pharmacological approaches are commonly used in caring for individuals with CRPS, they are frequently ineffective and often associated with side effects and/or additional risks. Previously, elastomeric orthotic garments have been shown to decrease neuropathic pain, reduce edema, and increase proprioception, but no previous reports have described their use in treating CRPS. Accordingly, this case series describes our experiences using a Lycra-based, custom-fabricated Dynamic Movement Orthosis (DMO) as a novel treatment to reduce the symptoms of CRPS and promote function. Four patients were included in this case series, all of whom had very different causes for their CRPS, including a combat-related gunshot injury resulting in multiple foot fractures with a partial nerve injury, a post-metatarsophalangeal fusion, an L5 radiculopathy, and a case of post-lower leg fasciotomies. These four patients all reported subjective improvement in their pain, function, and exercise tolerance in association with their DMO use. All patients demonstrated reduced use of analgesic medications. The pre- and post-DMO lower extremity functional scale showed clinically significant improvement in the two patients for which it was obtained.

What do patients value learning about pain? A mixed-methods survey on the relevance of target concepts after pain science education

ABSTRACT

Pain education is a popular treatment approach for persistent pain that involves learning a variety of concepts about pain (ie, target concepts), which is thought to be an important part of recovery. Yet, little is known about what patients value learning about pain. A mixed-methods survey was conducted to identify pain concepts that were valued by people with persistent pain who improved after a pain science education intervention. An online survey was distributed to 123 people who were treated for persistent pain with a pain science education approach; responses of participants who self-identified as "improved" were analysed. Open-ended survey questions were analysed using reflexive thematic analysis and close-ended questions were analysed for frequency of responses. Each question-type was analysed separately, before integration for complementarity. We analysed the data of 97 participants. We constructed 3 themes from the open-ended questions. Pain does not mean my body is damaged (theme 1) captured the importance of abandoning preexisting ideas that pain indicated damage. Thoughts, emotions and experiences affect pain (theme 2) captured the value of recognising multifactorial influences on pain. I can retrain my overprotective pain system (theme 3) captured the importance of conceptualising pain as a heightened protective response that could be lessened. Responses from close-ended questions confirmed that the target concepts represented by these themes are among those most valued, although divergence with the qualitative data suggests differences between patient and clinician language. These data offer patient-centred conceptualizations and language that could assist in further refining pain education interventions.

Complex Regional Pain Syndrome. A Comprehensive Review on Neuroplastic Changes Supporting the Use of Non-invasive Neurostimulation in Clinical Settings

Background: Complex regional pain syndrome (CRPS) is a rare debilitating disorder characterized by severe pain affecting one or more limbs. CRPS presents a complex multifactorial physiopathology. The peripheral and sensorimotor abnormalities reflect maladaptive changes of the central nervous system. These changes of volume, connectivity, activation, metabolism, etc., could be the keys to understand chronicization, refractoriness to conventional treatment, and developing more efficient treatments. Objective: This review discusses the use of non-pharmacological, non-invasive neurostimulation techniques in CRPS, with regard to the CRPS physiopathology, brain changes underlying chronicization, conventional approaches to treat CRPS, current evidence, and mechanisms of action of peripheral and brain stimulation. Conclusion: Future work is warranted to foster the evidence of the efficacy of non-invasive neurostimulation in CRPS. It seems that the approach has to be individualized owing to the integrity of the brain and corticospinal function. Non-invasive neurostimulation of the brain or of nerve/muscles/spinal roots, alone or in combination with conventional therapy, represents a fertile ground to develop more efficient approaches for pain management in CRPS.

Complex Regional Pain Syndrome: A Comprehensive Qualitative Research Study on Unmet Needs in the "Patient Journey"

Purpose

This qualitative research study aimed to characterize the "patient journey" for patients with complex regional pain syndrome (CRPS) and identify the unmet needs related to the management and treatment of the condition for healthcare providers (HCPs), patients, and their caregivers.

Materials and Methods

Multifaceted, dynamic methodology, iteratively gathering cognitive, emotional and social insights, was used to support and conduct in-depth, immersion interviews across the USA with 59 HCPs in-office and in roundtable discussions, and 20 patient-support partner dyads in-home.

Results

Patients were aged >18 years, primarily female, and all were diagnosed with CRPS (limited to type 1 in this patient cohort). Results show that the current state of CRPS treatment may fall short in multiple key areas. In some cases, poor awareness of CRPS causes delayed diagnoses impacting the opportunity for early treatment, resulting in long-term poor health outcomes. Consequently, the CRPS "patient journey" may be characterized by clinical frustration of physicians and disappointment for some patients. The poor treatment experiences and outcomes for some patients and HCPs may build the perception of a non-collaborative relationship. HCPs and patients agree that an effective treatment would be one that addresses CRPS rather than its symptoms, and the availability of such an option would transform the treatment experience.

Conclusion

CRPS leads to cognitive, social and emotional burdens for patients and their caregivers. There is an unmet need for improved CRPS disease awareness and successful therapeutic options to aid in earlier diagnoses, effective treatment and better outcomes for HCPs, patients, and their caregivers.

Classification of Qualitative Fieldnotes Collected During Quantitative Sensory Testing: A Step Towards the Development of a New Mixed Methods Approach in Pain Research

PURPOSE

Quantitative sensory testing (QST) is a standardized method to assess somatosensory function. The collection of qualitative information, during the QST procedure, could be an interesting way to facilitate the characterization of altered sensory perception and the identification of different pain phenotypes. The aims of this study were 1) to classify qualitative fieldnotes of sensory abnormalities collected during an independent QST study, and 2) to generate a qualitative interview guide that could be included in the traditional QST procedure as a step towards the implementation of a mixed methods approach.

PATIENTS AND METHODS

QST data were collected from 48 chronic neuropathic pain patients treated with spinal cord stimulation (SCS). Three body areas, with or without SCS, were tested: the painful limb targeted by SCS, the contralateral area, and the ipsilateral upper limb. After each trial of each QST modality, patients were encouraged to report any sensory abnormalities they could identify with a pain quality scale or using their own words.

RESULTS

Qualitative self-reported sensory abnormalities were dichotomized into two groups: altered sensory intensities and altered sensory perceptions. Altered sensory intensities were classified as sensory loss or sensory gain subgroups. Altered sensory perceptions were classified as paresthesia and dysesthesia subgroups Overall, 630 qualitative fieldnotes of altered sensations were collected: 385 on the painful limb, 173 at the contralateral area, and 72 at the ipsilateral upper limb. Based on these qualitative data, we propose a standardized method to collect qualitative data involving 9 open- and close-ended questions and 21 codes.

CONCLUSION

Our findings have highlighted the value of qualitative sensory evaluation during QST and constitute an important milestone in the development of a mixed methods protocol in phenotyping research.

Novel Presentation of Pediatric Complex Regional Pain Syndrome with Concurrent Chromhidrosis: A Case Report

CASE

An 11-year-old female patient presented to our clinic with a low-grade lateral ankle sprain that was subsequently treated with a lace-up ankle brace. On the reintroduction of weight bearing, the patient developed recurrent ankle pain and symptoms consistent with complex regional pain syndrome (CRPS) Type 1. On physical examination, the patient was found to have a concurrent chromhidrosis in the injured area, which is a novel presentation of CRPS.

CONCLUSION

Patients with CRPS found to have superficial skin discoloration should be evaluated further to investigate for chromhidrosis. Early diagnosis can improve the treatment of CRPS and allow for appropriate management of varying manifestations, such as chromhidrosis.

Visual illusions modulate body perception disturbance and pain in Complex Regional Pain Syndrome: A randomized trial

BACKGROUND

Effective treatment of longstanding Complex Regional Pain Syndrome (CRPS) is a challenge, as causal mechanisms remain elusive. People with CRPS frequently report distorted subjective perceptions of their affected limb. Evidence of pain reduction when the affected limb is visually altered in size suggests that visual illusions used to target central processing could restore coherence of this disrupted limb representation. We hypothesized that using virtual reality that alters hand image to match the patient's desired hand appearance would improve body perception disturbance and pain. Also, repeated exposure would maintain any therapeutic effect.

METHODS

A blinded randomized controlled trial of 45 participants with refractory upper-limb CRPS and body perception disturbance (BPD) viewed a digital image of their affected hand for 1 min. The image was digitally altered according to the patient's description of how they desired their hand to look in the experimental group and unaltered in the control group. BPD and pain were measured pre- and post-intervention. A subgroup was followed up 2 weeks after a course of repeated interventions.

RESULTS

BPD (mean-6, ±SD 7.9, p = 0.036, effect size [ES] = 0.6) and pain intensity (mean-0.43, ±SD 1.3, p = 0.047, ES = 0.5) reduced in 23 participants after single exposure compared to controls (n = 22). At follow-up, the subgroup (experimental n = 21; control n = 18) showed sustained pain reduction only (p = 0.037, ±SD 1.9, ES = 0.7), with an overall 1.2 decrease on an 11-point scale.

CONCLUSIONS

Visually changing the CRPS hand to a desired appearance modulates BPD and pain suggesting therapeutic potential for those with refractory CRPS. Further research to optimize this therapeutic effect is required.

SIGNIFICANCE

Visual bodily illusions that change the shape and appearance of the painful CRPS hand to that desired by the patient result in a rapid amelioration of pain and body perception disturbance in people with longstanding CRPS. These findings highlight the future potential of this drug-free approach in the treatment of refractory CRPS.

Multicenter survey of symptoms, work life, economic status, and quality of life of complex regional pain syndrome patients

Background

Complex regional pain syndrome (CRPS) is an intractable pain disease with various symptoms. Here, we investigated the disease status, work life, sleep problems, medical insurance, economic status, psychological problems, and quality of life (QOL) of CRPS patients.

Methods

CRPS patients from 37 university hospitals in South Korea were surveyed. The survey questionnaire consisted of 24 questions on the following aspects of CRPS patients sex, age, occupation, cause of injury, activities of daily living (ADL), pain severity, sleep disturbance, level of education, economic status, therapeutic effect, and suicidal ideation. Additionally, the abbreviated World Health Organization Quality of Life (WHOQOL-BREF) questionnaire, consisting of 26 questions, was used to identify the status of QOL.

Results

A total of 251 patients completed the questionnaire. According to the survey, 54.2% patients could not perform ADL on their own. Over the previous week, the mean pain score was 7.15 ± 1.78 (out of a total of 10 points); 92.1% of patients had sleep disorders and 80.5% had suicidal ideation, with most patients suffering from psychological problems. The average for each domain of WHOQOL-BREF was as follows 21.74 ± 14.77 for physical, 25.22 ± 17.66 for psychological, 32.02 ± 22.36 for social relationship, and 30.69 ± 15.83 for environmental (out of a total of 100 points each). Occupation, ADL, sleep time, therapeutic effect, and suicidal ideation were statistically correlated with multiple domains.

Conclusions

Most patients had moderate to severe pain, economic problems, limitations of their ADL, sleep problems, psychological problems, and a low QOL score.

Bier block as a successful management of a patient with intractable complex regional pain syndrome (CRPS) type 1: A case report

Bier block was successful in the pain management of complex regional pain syndrome (CRPS) type 1.

Intramuscular neridronate for the treatment of complex regional pain syndrome type 1: a randomized, double-blind, placebo-controlled study

Background:

Complex regional pain syndrome type-1 (CRPS-1) is a severely disabling painful disease challenging to treat. This multicenter, randomized, double-blind placebo-controlled trial examined the efficacy of intramuscular (i.m.) neridronate in CRPS-1 patients.

Methods:

A total of 78 patients diagnosed with CRPS-1 (aged 59.5 ± 10.3, 66.7% female) were randomly assigned to 25 mg (i.m.) neridronate (N = 41) given once daily for 16 consecutive days or placebo control (N = 37). Efficacy was assessed after 30 days using a visual analogue scale (VAS) pain score and the number of patients achieving ⩾50% reduction in VAS score. Change in clinical signs and symptoms, quality of life (QoL) using Short Form Health Survey (SF-36) and the McGill Pain Questionnaire were also assessed.

Results:

After 30 days, VAS score decreased significantly to a greater extent in neridronate-treated patients versus placebo (31.9 ± 23.3 mm versus 52.3 ± 27.8 mm, p = 0.0003). Furthermore, the proportion of patients achieving a VAS reduction of ⩾50% was greater in the neridronate group (65.9% versus 29.7%, p = 0.0017). Clinical signs and symptoms were improved significantly in the neridronate group versus placebo for edema (72.5% versus 79.9%, p = 0.03), pain during motion (70% versus 83.3%, p = 0.0009), allodynia (20% versus 63.3%, p = 0.0004), and hyperalgesia (20% versus 56.7%, p = 0.0023). Whereas no difference was observed for QoL measures using the SF-36 questionnaire, three of the four pain variables using the McGill Pain Questionnaire improved significantly in the neridronate group. No serious drug-related adverse events were reported during the study.

Conclusion:

In patients with acute CRPS-1, i.m. injections of 25 mg neridronate were associated with clinically relevant benefit compared with placebo controls.

Trial registration:

EU Clinical Trials Register: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-001156-28

Quantitative Analysis of Real-Time Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks: A Preliminary Study

Lumbar sympathetic blocks (LSBs) are commonly performed to treat pain ailments in the lower limbs. LSBs involve injecting local anesthetic around the nerves. The injection is guided by fluoroscopy which is sometimes considered to be insufficiently accurate. The main aim was to analyze the plantar foot skin temperature data acquired while performing LSBs in patients with complex regional pain syndrome (CRPS) affecting the lower limbs. Forty-four LSBs for treating lower limb CRPS in 13 patients were assessed. Pain medicine physicians visualized the infrared thermography (IRT) video in real time and classified the performance depending on the observed thermal changes within the first 4 min. Thirty-two percent of the cases did not register temperature variations after lidocaine was injected, requiring the needle to be relocated. Differences between moments are indicated using the 95% confidence intervals of the differences (CI 95%), the Cohen effect size (ES) and the significance (p value). In successful cases, after injecting lidocaine, increases at minute 7 for the mean (CI 95% (1.4, 2.1 °C), p < 0.001 and ES = 0.5), at minute 5 for maximum temperature (CI 95% (2.3, 3.3 °C), p < 0.001 and ES = 0.6) and at minute 6 for SD (CI 95% (0.2, 0.3 °C), p < 0.001 and ES = 0.5) were observed. The results of our preliminary study showed that the measurement of skin temperature in real time by infrared thermography is valuable for assessing the success of lumbar sympathetic blocks.

Alpha 1 adrenoceptor expression in skin, nerves and blood vessels of patients with painful diabetic neuropathy

Diabetic neuropathy (dNP) patients often suffer from severe neuropathic pain. It was suggested that alpha-1 adrenoceptor (α₁-AR) hyperresponsiveness contributes to pain in dNP. The aim of our study was to quantify α₁-AR expression using immunohistochemistry in skin biopsies of nine patients with painful diabetic neuropathy compared to 10 healthy controls. Additionally, the association between α₁-AR expression and activation with spontaneous and sympathetically maintained pain (SMP) induced by intradermal injection of the α₁-agonist phenylephrine was investigated. For control purposes the α₂-agonist clonidine was injected in a different session. We found that dermal nerve density was significantly lower in dNP than in controls. However, α₁-AR expression was significantly greater on cutaneous blood vessels and keratinocytes of dNP patients than controls. A similar trend, which failed to reach significance, was observed for dermal nerves. Intradermal injection of phenylephrine induced only minor pain, which resolved after a few minutes. Adrenergically evoked pain persisted for more than 15 min in only one patient, but none of the patients fulfilled the criteria for SMP (pain increase after injection of phenylephrine and decrease after clonidine). In conclusion, our results imply that SMP does not occur in dNP. However, elevated expression of α₁-AR on keratinocytes and dermal blood vessels is an important finding, since this could contribute to dNP progression and supports the theory of receptor up-regulation of denervated structures. The implications of this α₁-upregulation should be examined in further studies.

Pain Phenotypes in Rare Musculoskeletal and Neuromuscular Diseases

For patients diagnosed with a rare musculoskeletal or neuromuscular disease, pain may transition from acute to chronic; the latter yielding additional challenges for both patients and care providers. We assessed the present understanding of pain across a set of ten rare, noninfectious, noncancerous disorders; Osteogenesis Imperfecta, Ehlers-Danlos Syndrome, Achondroplasia, Fibrodysplasia Ossificans Progressiva, Fibrous Dysplasia/McCune-Albright Syndrome, Complex Regional Pain Syndrome, Duchenne Muscular Dystrophy, Infantile- and Late-Onset Pompe disease, Charcot-Marie-Tooth Disease, and Amyotrophic Lateral Sclerosis. Through the integration of natural history, cross-sectional, retrospective, clinical trials, & case studies we described pathologic and genetic factors, pain sources, phenotypes, and lastly, existing therapeutic approaches. We highlight that while rare diseases possess distinct core pathologic features, there are a number of shared pain phenotypes and mechanisms that may be prospectively examined and therapeutically targeted in a parallel manner. Finally, we describe clinical and research approaches that may facilitate more accurate diagnosis, monitoring, and treatment of pain as well as elucidation of the evolving nature of pain phenotypes in rare musculoskeletal or neuromuscular illnesses.

Resource Use and Cost of Subcutaneous Nerve Stimulation Versus Optimized Medical Management in Patients With Failed Back Surgery Syndrome: An Analysis of the SubQStim Study

OBJECTIVES

To undertake a detailed healthcare resource use and cost analysis of the SubQStim study, which randomized patients with failed back surgery syndrome (FBSS) with low back pain to receive subcutaneous nerve field stimulation in combination with optimized medical management (treatment) or optimized medical management alone (control).

MATERIALS AND METHODS

Patient-level data from the SubQStim study were used to present descriptive analyses of healthcare resource use and estimated costs for pain medication, healthcare visits, adverse events, and device acquisition/implantation. A United Kingdom National Health Service perspective was adopted, using cost data from national tariffs, drug and device prices, and social care cost studies. Results were calculated as the mean cost per patient over the nine-month follow-up period.

RESULTS

Mean cost per patient was £18,403 in the treatment group versus £1613 in the control group. Almost 90% of the cost in the treatment group consisted of device acquisition/implantation. Higher adverse event costs were observed for patients in the treatment group, but lower costs were observed for pain medication and healthcare visits. Over nine months, opioid use decreased in the treatment group and increased in the control group. Enrolment and follow-up were terminated early in the clinical study, leading to substantial between-patient variability in each cost category.

CONCLUSIONS

Subcutaneous nerve field stimulation has the potential to offset the initial costs of the device by reducing analgesic medication and the number of healthcare visits in FBSS patients, alongside potential gains in health-related quality of life. There remains uncertainty in long-term costs and cost-effectiveness of stimulation and longer-term follow-up analyses are needed.

Mechanistic Rationale and Clinical Efficacy of Hyperbaric Oxygen Therapy in Chronic Neuropathic Pain: An Evidence-Based Narrative Review

Background

Chronic neuropathic pain is a condition affecting an increasing proportion of the general population and its management requires a comprehensive, multidisciplinary program. A growing body of evidence supports the use of hyperbaric oxygen therapy (HBOT) in several chronic neuropathic pain conditions; however, its role and efficacy remain unclear.

Purpose

To summarize current evidence for the mechanistic rationale of HBOT in chronic neuropathic pain conditions and to evaluate its clinical efficacy.

Methods

This narrative review was conducted after searching the following databases (Medline, Embase, Cochrane, PsycINFO, the Web of Science, Scopus, ClinicalTrials. gov, WHO ICTRP, and ProQuest Digital Dissertation) from January 1946 to March 2020. Articles published in English that involved either animal or human studies with acute or chronic neuropathic pain evaluating any HBOT-related intervention were included.

Results

A total of 2971 citations were identified. A total of 29 studies were included in this review. The mechanisms of action for HBOT use in neuropathic conditions included the primary effects of hyperoxia and edema resolution, as well as the secondary effects pertinent to the production of oxygen and nitrogen reactive species (serving as pain signaling molecules), nitric oxide-dependent release of opioid peptides, and reduction of inflammatory mediators. A robust evidence for HBOT use in the clinical setting was associated with chronic regional pain syndrome and chronic primary bladder pain syndrome. Some evidence supported its use for chronic secondary (peripheral) neuropathic pain including radiation-induced plexus neuropathies, postherpetic neuralgia, and trigeminal neuralgia.

Conclusions

HBOT has been shown to have antinociceptive and analgesic effects in animal models of inflammatory, neuropathic, and chronic pain. Human studies demonstrated beneficial effects of HBOT in improving clinical outcomes such as pain scores, pain-related symptoms, and quality of life. A systematic methodology of HBOT application is necessary to confirm its safety and efficacy.

Patients Describe their Lived Experiences of Battling to Live with Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) has never comprehensively been examined from a lived experience perspective. Patients generally have a poorer quality of life than people with other chronic pain conditions. This study aimed to understand the essence of living with CRPS. Data were collected from 17 patients via in-depth interviews. Hermeneutic discussions with four health professionals generated deeper insights. Internet blogs and a book containing patient stories were included for theme verification and triangulation. CRPS is seen as a war-like experience and five themes were identified within the battle: "dealing with the unknown enemy", "building an armoury against a moving target", "battles within the war", "developing battle plans with allies" and "warrior or prisoner of war". Patients live with a chronic pain condition and experience problems unique to CRPS such as fear of pain extending to other parts of their body. Use of the model generated by this research may assist patient/clinician interactions and guide therapeutic discussions. Support for people living with CRPS does not always exist, and some healthcare professionals require additional education about the condition. Better health outcomes are experienced by patients when their personal situation and experiences are heard and understood by health care professionals. PERSPECTIVE: This article presents the lived experience of CRPS. This information and the model generated can help clinicians to better understand their patients and deliver appropriate patient-centered care.