Standards for the diagnosis and management of complex regional pain syndrome: Results of a European Pain Federation task force

A brief review of complex regional pain syndrome and current management

Complex regional pain syndrome (CRPS) is a debilitating chronic pain condition that, although exceedingly rare, carries a significant burden for the affected patient population. The complex and ambiguous pathophysiology of this condition further complicates clinical management and therapeutic interventions. Furthermore, being a diagnosis of exclusion requires a diligent workup to ensure an accurate diagnosis and subsequent targeted management. The development of the Budapest diagnostic criteria helped to consolidate existing definitions of CRPS but extensive work remains in identifying the underlying pathways. Currently, two distinct types are identified by the presence (CRPS type 1) or absence (CRPS type 2) of neuronal injury. Current management directed at this disease is broad and growing, ranging from non-invasive modalities such as physical and psychological therapy to more invasive techniques such as dorsal root ganglion stimulation and potentially amputation. Ideal therapeutic interventions are multimodal in nature to address the likely multifactorial pathological development of CRPS. Regardless, a significant need remains for continued studies to elucidate the pathways involved in developing CRPS as well as more robust clinical trials for various treatment modalities.

Comparing sucrose solution with distilled water for pain management in premature infant venipuncture: randomized clinical trial

Introduction and importance

Managing pain is critical, especially for premature infants undergoing frequent painful procedures. Uncontrolled pain can lead to lasting harm in growth, cognitive development, and future pain responses.

Methods

A double-blinded clinical investigation involving 150 premature infants was performed in a neonatal intensive care unit. They were randomly divided into three groups: Sucrose 20% (50 infants), distilled water (50 infants), and a control group (50 infants). The infants' behavioral responses were assessed using an infant pain measurement tool before, at 2, and 7 min after the intervention through direct observation.

Results

The study revealed that mean pain scores before, 2 min after, and 7 min after the intervention in the sucrose group were (4.78±0.91), (3.18±1.15), and (2±1.02), respectively. In the distilled water group, scores were (4.66±0.89), (3.04±1.15), and (3.08±1.10), while in the control group, they were (4.0±0.79), (4.94±0.79), and (4.72±0.96). The trend of pain scores varied among the groups over time, with a significant difference in mean pain scores at different time points (P<0.001). Initially comparable, pain scores notably decreased after 2 min in the sucrose and distilled water groups (P<0.001), differing from the control group.

Conclusion

The study indicated that 20% sucrose and distilled water equally reduce infant pain post-venipuncture, suggesting their viability for clinical pain management. Distilled water, however, provides additional benefits, including economic considerations and ease of preparation.

3D printed splint designed by 3D surface scanner for patients with hand allodynia

Allodynia is a neuropathic pain triggered by a normally painless stimulus: for example, a slight touch on the skin or slight sensation of hot or cold is extremely painful. Rehabilitation is long and uncertain. Protecting the painful area from stimuli is a priority of care. This type of care is complex and challenging for the care team: the pain caused in manufacturing a classic molded orthosis is unbearable for the patient, and the orthosis has a limited lifetime, and experience shows that it is not possible to produce two identical splints. The present study consisted in creating protective splints by 3D printing, designed from data collected with the 3D surface scanner used in our forensic imaging and anthropology unit. The pros and cons of the 3D orthosis versus standard molded orthoses from the point of view of the patient and the practitioner are discussed, with evaluation of related indications of this technology.

Complex Regional Pain Syndrome after Distal Radius Fracture-Case Report and Mini Literature Review

This study explores the impact of the complex regional pain syndrome (CRPS) on the lives and mobility of patients, with a particular focus on its emergence as a late complication of distal radius fractures (DRFs), a common occurrence, especially among an aging population. The absence of a standardized treatment for the CRPS and the challenge of predicting its occurrence make it a complex medical issue. This research aims to shed light on the effects of treating the CRPS through a case study involving a 75-year-old woman with untreated osteoporosis who experienced a Colles fracture after a fall. The initial management involved repositioning and stabilizing the fractured forearm with a plaster cast, followed by an operation using percutaneous pinning via a Kirschner wire. Subsequently, the patient developed CRPS symptoms and was admitted to the rehabilitation department three months post-fracture. The affected forearm exhibited swelling, warmth, pain, and severely limited range of motion. Treatment involved a combination of medications, physiotherapy, and kinesiotherapy. Significantly, the patient experienced notable improvement following these interventions. This study underscores the absence of a definitive standard for CRPS treatment but suggests that proper rehabilitation and pharmaceutical interventions can contribute positively to patient outcomes. The case further highlights the potential association between DRF and CRPS development, emphasizing the need for continued research in this field.

An update on the pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Participatory design of an infographic to help support the care of people living with complex regional pain syndrome

Background

Complex regional pain syndrome (CRPS) can be a debilitating pain condition with enduring physical, psychological and social impacts. CRPS is often poorly understood by healthcare professionals and management needs to be tailored to each individual's presentation. People with lived experience express difficulty in accessing reliable and meaningful information about the condition. This study aimed to co-create a trustworthy infographic to share information about the lived experience of CRPS.

Methods

We adopted a seven-phase, iterative, participatory methodology to co-create the infographic. Potential infographic content was obtained from qualitative work investigating the lived experience of CRPS. Online consumer engagement (people with doctor diagnosed CRPS/their family, n=20) was used to prioritise content to be included in the infographic and then potential designs were sourced. The research team narrowed the selections down to two designs which were presented to consumers online for final selection (n=25) and refinement (n=34).

Results

An infographic for understanding the lived experience of CRPS was completed using participatory design, providing a resource aligned to the needs of people with this condition. Using the Patient Education Materials Assessment Tool, the final infographic rated highly for understandability (92%) and participants indicated significant willingness to share this infographic with others (93%).

Conclusion

A process of participatory design was an effective and efficient process for translation of evidence gathered from qualitative research into a trustworthy resource for people with CRPS and their support people.

Treating persistent pain after breast cancer: practice gaps and future directions

This paper discusses the growing problem of persisting pain after successful treatment of breast cancer and presents recommendations for improving pain-related outcomes for this group. We discuss the dominant treatment approach for persisting pain post-breast cancer treatment and draw contrasts with contemporary treatment approaches to persistent pain in non-cancer-related populations. We discuss modern application of the biopsychosocial model of pain and the notion of variable sensitivity within the pain system, moment by moment and over time. We present the implications of increasing sensitivity over time for treatment selection and implementation. By drawing on transformative changes in treatment approaches to persistent non-cancer-related pain, we describe the potentially powerful role that an intervention called pain science education, which is now recommended in clinical guidelines for musculoskeletal pain, may play in improving pain and disability outcomes after successful breast cancer treatment. Finally, we present several research recommendations that centre around adaptation of the content and delivery models of contemporary pain science education, to the post-breast cancer context.

Optimising management of complex regional pain syndrome to improve clinical outcomes throughout the therapy care pathway in England: Protocol for a qualitative interview and observational study with patients and clinicians

INTRODUCTION

Complex Regional Pain Syndrome (CRPS) is a disabling and distressing chronic pain condition characterised by a range of sensory, motor, autonomic and trophic symptoms. Guidelines recommend early referral for therapies that promote movement of the painful limb. However, evidence suggests a lack of defined therapy pathways for CRPS.

AIMS

The current study aims to explore CRPS therapy management in centres of excellence in England, and outside of these settings, to understand what facilitates and hinders best practice. The overall aim is to develop a draft stratified package of care to expedite patient access to optimal CRPS therapy across the management pathway.

METHODS AND ANALYSIS

Semi-structured interviews will be conducted with therapists working in CRPS centres of excellence and with therapists in other settings. Observations of therapy interventions in CRPS centres of excellence and interviews with patients who have received this care, will also help to identify potential key care package components. Interview data will be analysed using thematic analysis, mapped to the Theoretical Domains Framework (TDF), and Intervention Mapping Adapt (IMA) framework. Observations will be described and documented using the TDF headings.

CONCLUSION

A triangulation protocol for qualitative health research will be used to integrate all data. Online stakeholder events will be held using consensus methods to agree a draft package of care for future implementation following further refinement, testing and evaluation.

CLINICAL TRIAL REGISTRATION

The trial was registered with ISRCTN registry on 24 February 2022 (ISRCTN16917807).

Complex Regional Pain Syndrome (CRPS) and the Value of Early Detection

PURPOSE OF REVIEW

The goal of this narrative review is to describe the current understanding of the pathology of Complex Regional Pain Syndrome (CRPS), as well as diagnostic standards and therapeutic options. We will then make the case for early recognition and management.

RECENT FINDINGS

CRPS remains an enigmatic pain syndrome, comprising several subtypes. Recent recommendations clarify diagnostic ambiguities and emphasize the importance of standardized assessment and therapy. Awareness of CRPS should be raised to promote prevention, early detection, and rapid escalation of therapy in refractory cases. Comorbidities and health costs (i.e., the socioeconomic impact) must also be addressed early to prevent negative consequences for patients.

Complex Regional Pain Syndrome: Evidence-Based Advances in Concepts and Treatments

PURPOSE OF REVIEW

This review presents the most current information about the epidemiology of complex regional pain syndrome (CRPS), classification and diagnostic criteria, childhood CRPS, subtypes, pathophysiology, conventional and less conventional treatments, and preventive strategies.

RECENT FINDINGS

CRPS is a painful disorder with multifactorial pathophysiology. The data describe sensitization of the central and peripheral nervous systems, inflammation, possible genetic factors, sympatho-afferent coupling, autoimmunity, and mental health factors as contributors to the syndrome. In addition to conventional subtypes (type I and type II), cluster analyses have uncovered other proposed subtypes. Prevalence of CRPS is approximately 1.2%, female gender is consistently associated with a higher risk of development, and substantial physical, emotional, and financial costs can result from the syndrome. Children with CRPS seem to benefit from multifaceted physical therapy leading to a high percentage of symptom-free patients. The best available evidence along with standard clinical practice supports pharmacological agents, physical and occupational therapy, sympathetic blocks for engaging physical restoration, steroids for acute CRPS, neuromodulation, ketamine, and intrathecal baclofen as therapeutic approaches. There are many emerging treatments that can be considered as a part of individualized, patient-centered care. Vitamin C may be preventive. CRPS can lead to progressively painful sensory and vascular changes, edema, limb weakness, and trophic disturbances, all of which substantially erode healthy living. Despite some progress in research, more comprehensive basic science investigation is needed to clarify the molecular mechanisms of the disease so that targeted treatments can be developed for better outcomes. Incorporating a variety of standard therapies with different modes of action may offer the most effective analgesia. Introducing less conventional approaches may also be helpful when traditional treatments fail to provide sufficient improvement.

Imaging Modalities and Their Findings in Patients With Complex Regional Pain Syndrome: A Review

Complex regional pain syndrome (CRPS) is a systemic or regional pain pathology associated with the nondermatomal or dermatomal distribution of excruciating intolerable pain, which might be triggered by an insignificant or weak stimulus or sometimes without any. Its symptoms encompass neurological, musculoskeletal, dermatological, and vascular realms. It is usually preceded by an episode of nerve injury or intervention set in numerous circumstances ranging from trauma to surgeries to chronic diseases. CRPS has been shrouded in a veil of mystery and was called a psychological phenomenon without any proper organic basis when it was described by Ambroise Pare initially. This led to disproportionately fewer research investments into this disease. Given the great advancement of diagnostic modalities since its inception, researchers and physicians have been trying to identify the physiological basis for it and have succeeded. Numerous pathophysiological pathways have been involved in this disease, but all of them point toward the possibility of improper pain processing at various levels of the pain pathway along with brain plasticity leading to aberrant neuronal circuitry between different segments of the sensory cortex, basal ganglia, prefrontal cortex, and insula. This paper explores the various studies done to evaluate the role of different imaging modalities, ranging from three-phase bone scintigraphy (TPBS) to diffusion traction imaging (DTI).

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.

AUTHORS' CONCLUSIONS

Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

Managing Chronic Regional Pain Syndrome: The Potential Impact of the Food and Drug Omnibus Reform Act

Complex regional pain syndrome (CRPS) is a neurological disorder characterized by persistent limb symptoms. With there being no definitive tests, diagnosis can be challenging. The Budapest criteria are the standard for diagnosis. The underlying mechanisms of CRPS involve changes in skin innervation, sensitization of the nervous system, inflammatory cytokines, and genetic and psychological factors. Treatment typically involves a multidisciplinary approach. We present a case of a 71-year-old male with CRPS involving the right upper extremity and a complex history of management including physical therapy, oxycodone, muscle relaxers, non-steroidal anti-inflammatory drugs, and multiple stellate ganglion blocks. The patient manages his pain with off-label medications, including methadone, duloxetine, and pregabalin. In the United States, the management of chronic pain may be affected by potential usage restrictions imposed by the Food and Drug Omnibus Reform Act (FDORA). Under this new act, physicians may face limitations in prescribing off-label medications for specific diagnoses. We aim to highlight the need for prioritizing patient care and individualized treatment in healthcare policy decision-making.

Effect and mechanisms of exercise for complex regional pain syndrome

Complex regional pain syndrome characterized by severe pain and dysfunction seriously affects patients' quality of life. Exercise therapy is gaining attention because it can effectively relieve pain and improve physical function. Based on the previous studies, this article summarized the effectiveness and underlying mechanisms of exercise interventions for complex regional pain syndrome, and described the gradual multistage exercise program. Exercises suitable for patients with complex regional pain syndrome mainly include graded motor imagery, mirror therapy, progressive stress loading training, and progressive aerobic training. In general, exercise training for patients with complex regional pain syndrome not only alleviates pain but also improves physical function and positive mental status. The underlying mechanisms of exercise interventions for complex regional pain syndrome include the remodeling of abnormal central and peripheral nervous system, the regulation of vasodilation and adrenaline levels, the release of endogenous opioids, and the increased anti-inflammatory cytokines. This article provided a clear explanation and summary of the research on exercise for complex regional pain syndrome. In the future, more high-quality studies with sufficient sample sizes may provide more exercise regimens and better evidence of efficacy.

Occupational therapy treatment of complex regional pain syndrome in children and adolescents: a scoping review protocol

OBJECTIVE

This scoping review will explore the literature related to occupational therapy interventions and delivery methods for pediatric complex regional pain syndrome.

INTRODUCTION

Complex regional pain syndrome is a debilitating pain condition that is becoming increasingly diagnosed within the pediatric population. Untreated, it can negatively impact a child's occupational engagement and participation, social functioning, and family dynamics. A multidisciplinary treatment approach is typically recommended, with occupational therapy as an essential component. Occupational therapy interventions for pediatric complex regional pain syndrome usually promote a child's ability to participate in daily activities to prevent further impairment and disability. Despite evidence that occupational therapy practitioners treat this population, no review has been conducted of the available literature on occupational therapy interventions for pediatric complex regional pain syndrome.

INCLUSION CRITERIA

This review will consider studies that include any form of occupational therapy interventions for participants with complex regional pain syndrome who are 18 years or younger. Quantitative, qualitative, and observational studies, and text and opinion papers will be considered.

METHODS

The JBI methodology will be used to conduct this scoping review. MEDLINE, Embase, Scopus, APA PsycINFO, CINAHL, OTDBASE, OT Search (AOTA), OTseeker, and ProQuest Dissertations and Theses Global will be searched for studies in English, with no limit on publication date. Two independent reviewers will screen the titles, abstracts, and full texts of the selected studies. Data collection will be performed using a tool developed by the researchers based on the standardized JBI tool. Data will be presented in a comprehensive narrative summary.

Modern Principles of Diagnosis and Treatment in Complex Regional Pain Syndrome

BACKGROUND

Background: Complex regional pain syndrome (CRPS) is a relatively common complication, occurring in 5% of cases after injury or surgery, particularly in the limbs. The incidence of CPRS is around 5-26/100 000. The latest revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) now categorizes CRPS as a primary pain condition of multifactorial origin, rather than a disease of the skeletal system or the autonomic nervous system.

METHODS

Method: Based on a selective search of the literature, we summarize current principles for the diagnosis and treatment of CRPS.

RESULTS

Results: Regional findings in CRPS are accompanied by systemic symptoms, especially by neurocognitive disorders of body perception and of symptom processing. The therapeutic focus is shifting from predominantly passive peripheral measures to early active treatments acting both centrally and peripherally. The treatment is centered on physiotherapy and occupational therapy to improve sensory perception, strength, (fine) motor skills, and sensorimotor integration/ body perception. This is supported by stepped psychological interventions to reduce anxiety and avoidance behavior, medication to decrease inflammation and pain, passive physical measures for reduction of edema and of pain, and medical aids to improve functioning in daily life. Interventional procedures should be limited to exceptional cases and only be performed in specialized centers. Spinal cord and dorsal root ganglion stimulation, respectively, are the interventions with the best evidence.

CONCLUSION

Conclusion: The modern principles for the diagnosis and treatment of CRPS consider both, physiological and psychological mechanisms, with the primary goal of restoring function and participation. More research is needed to strengthen the evidence base in this field.

Harmful or safe? Exposure and pain provocation during physiotherapy of complex regional pain syndrome I: a narrative review

BACKGROUND

Complex regional pain syndrome (CRPS) is a clinical diagnosis and an umbrella term for a heterogeneous group of states associated with pain disproportionate to any inciting event, together with a number of signs and symptoms that are manifested mainly in the limbs. There are often concerns among clinicians and patients about the potential harms caused by pain provocation during physiotherapy of CRPS, even though clinical guidelines de-emphasize pain-contingency.

OBJECTIVE

The objective of this narrative review is to summarize current evidence regarding potential harms due to pain provocation during so-called exposure-based therapies in individuals with CRPS.

METHODS

Six studies evaluating exposure-based approach were included (n= 6).

RESULTS

Although only one included study focused primarily on safety and in the rest of the included studies the reporting of harms was insufficient and therefore our certainty in evidence is very low, taken together with outcome measures, available data does not point to any long-term deterioration in symptoms or function, or any major harms associated with pain provocation during physiotherapy of CRPS.

CONCLUSION

There is a great need for higher-quality studies to determine which therapeutic approach is the most appropriate for whom and to evaluate the risks and benefits of different approaches in more detail.

A Complex Regional Pain Syndrome Imaging Journal: Case Report

Complex regional pain syndrome (CRPS) poses a diagnostic and management challenge for many clinicians, particularly when disease symptomatology waxes and wanes. Monitoring symptom variations with digital and infrared thermal images allows for more accurate evaluation of disease progression overtime. We present the case of a patient who developed CRPS and catalog his symptoms using a digital and infrared thermal imaging diary. The images were instrumental toward establishing the initial diagnosis of CRPS, monitoring disease progression, and assessing response to treatment. We discuss the present understanding of infrared thermography in CRPS and advocate for its routine use at the beside.

Assessment of body perception disturbances in complex regional pain syndrome: A systematic review using the COSMIN guideline

OBJECTIVE

To conduct a systematic review to identify which tools are being used to assess body perception disturbances in Complex Regional Pain Syndrome (CRPS) and to provide an evidence-based recommendation in the selection of an assessment tool, based on measurement properties.

DATABASES AND DATA TREATMENT

Five electronic databases (EMBASE, Pubmed, PsycInfo, Science Direct and Web of Science) were searched for English or French written articles, with no time restrictions. All original articles using a body perception assessment tool with adult patients with CRPS were selected, regardless of their design (controlled trials, single case, qualitative study). Two investigators screened abstracts, selected full articles and extracted data independently.

RESULTS

Thirty-eight full-text papers were obtained and three main methods to evaluate body perception disturbances were identified: The Bath Body Perception Disturbance Scale, the Neglect-like Symptoms questionnaire adapted from Galer and the patient's body perception description. No full psychometric assessments were found. The Limb Laterality Recognition Task was also used in conjunction with another method.

CONCLUSIONS

Three main assessment methods for CRPS body perception disturbances are currently used. Full psychometric evaluation has not been completed for any of the assessment methods. As a consequence, we could not fully apply the COSMIN guideline. To date, there is no agreement concerning the use of a specific questionnaire or scale. The results indicate a need for further research such as psychometric properties of these questionnaires.

SIGNIFICANCE

This systematic review identified body perception disturbances assessment methods and their the psychometric properties in order to provide help and guidance to researchers and clinicians to investigate those clinical features.

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.

Complex Regional Pain Syndrome or Limb Pain: A Plea for a Critical Approach

Most frequently, complex regional pain syndrome (CRPS) develops after a trauma and affects distal parts of the limbs. Early recognition and initiation of adequate treatment is crucial for a favorable outcome. On the other hand, misdiagnosing other disorders as CRPS is detrimental because more appropriate treatment may be withheld from the patients. Despite intensive research, a specific biomarker or paraclinical measure for CRPS diagnosis is still lacking. Instead, clinical criteria approved by the International Association for the Study of Pain (IASP) and latest adapted in 2019 are central for diagnosing CPRS. Thus, the CRPS diagnosis remains challenging with the risk of a “deliberate diagnosis” for unexplained pain, while at the same time a delayed CRPS diagnosis prevents early treatment and full recovery. CRPS is a diagnosis of exclusion. To clinically diagnose CRPS, a vigorous exclusion of “other diseases that would better explain the signs and symptoms” are needed before the patients should be referred to tertiary centers for specific pain treatment. We highlight red flags that suggest “non-CRPS” limb pain despite clinical similarity to CRPS. Clinical and neurological examination and paraclinical evaluation of a probably CRPS patient are summarized. Finally, we pinpoint common differential diagnoses for CRPS. This perspective might help CRPS researchers and caregivers to reach a correct diagnosis and choose the right treatment, regardless whether for CRPS mimics or CRPS itself.

Discovery of novel targets in a complex regional pain syndrome mouse model by transcriptomics: TNF and JAK-STAT pathways

Complex Regional Pain Syndrome (CRPS) represents severe chronic pain, hypersensitivity, and inflammation induced by sensory-immune-vascular interactions after a small injury. Since the therapy is unsatisfactory, there is a great need to identify novel drug targets. Unbiased transcriptomic analysis of the dorsal root ganglia (DRG) was performed in a passive transfer-trauma mouse model, and the predicted pathways were confirmed by pharmacological interventions. In the unilateral L3-5 DRGs 125 genes were differentially expressed in response to plantar incision and injecting IgG of CRPS patients. These are related to inflammatory and immune responses, cytokines, chemokines and neuropeptides. Pathway analysis revealed the involvement of Tumor Necrosis Factor (TNF) and Janus kinase (JAK-STAT) signaling. The relevance of these pathways was proven by abolished CRPS IgG-induced hyperalgesia and reduced microglia and astrocyte markers in pain-associated central nervous system regions after treatment with the soluble TNF alpha receptor etanercept or JAK inhibitor tofacitinib. These results provide the first evidence for CRPS-related neuroinflammation and abnormal cytokine signaling at the level of the primary sensory neurons in a translational mouse model and suggest that etanercept and tofacitinib might have drug repositioning potentials for CRPS-related pain.

Educational considerations for health professionals to effectively work with clients with complex regional pain syndrome

Introduction

People living with complex regional pain syndrome (CRPS), a rare chronic pain disorder, must become experts in their own self-management. Listening to the voice of the patient is often advocated in the pain literature. However, the patient’s option is rarely asked for or considered by clinicians, even when they live with a condition that health professionals have rarely heard of.

Purpose

To explore what people living with complex regional pain syndrome (CRPS) think health professionals should know about their condition to provide appropriate care.

Design

A heuristic, hermeneutic phenomenological study was conducted asking people about their experiences living with CRPS. This paper reports on the findings of an additional question asked of all participants.

Participants

Seventeen people living with complex regional pain syndrome were interviewed.

Findings

Overwhelmingly, participants felt that health professionals do not know enough about CRPS, or chronic pain and believe their health outcomes are affected by this lack of knowledge. Sub-themes identified were don’t touch unless I say it is okay; be patient with the patient/ it is important to develop a relationship; educate yourself and educate the patient; choose your words carefully and refer to others as needed. An additional theme, it is very hard to describe CRPS was also identified.

Conclusions

Including patients as a member of the healthcare team is recommended to help people take control and self-manage their pain. For true patient centered care to be achieved, health professionals must accept and respect patients’ descriptions of pain and their pain experience. This may require additional health professional education at both undergraduate and post-graduate levels in pain and communication to increase their bedside manner and therapeutic communication to deliver care in partnership with the patient.

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.

What do I need to know? Essential educational concepts for complex regional pain syndrome

Background

Methods

Results

Conclusion

Significance

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.

[Complex regional pain syndrome-An update]

Complex regional pain syndrome (CRPS) is a pain disorder that develops in the hands or feet after injury. Currently, two types are differentiated, CRPS I without and CRPS II with nerve lesions as well as with either an initially warm or an initially cold subtype, depending on the clinical symptoms. After trauma a certain amount of inflammatory reaction is considered physiological. In acute CRPS this inflammation persists for months and is maintained by diverse inflammatory mediators in peripheral tissue and in blood. This persisting inflammation leads to a sensitization of the nociceptive system, causes somatic cells to proliferate and gives rise to a disrupted endothelial function. The treatment concept aims to antagonize the pathophysiologic components and includes anti-inflammatory and analgetic treatment, mobilization and restoration of the sensorimotor function of the affected limb.

Complex regional pain syndrome after severe COVID-19 - A case report

Neurological complications are frequently reported in an intensive care unit (ICU), as a manifestation of a critical systemic illness or of its treatment. On the specific setting of COVID-19 patients, peripheral nerve lesions can have a multiplicity of causes, such as post-infectious neuropathy, positioning-related neuropathy or iatrogeny. An unusual but potentially disabling complication of any peripheral nerve lesion is Complex Regional Pain Syndrome (CRPS). Although there have been no mechanistic studies assessing how SARS-CoV-2 might directly impact nociception, it is hypothesized that the systemic hyperinflammation seen in severe COVID-19 may contribute to peripheral and central neuronal sensitization, possibly increasing the risk of developing CRPS. This case report highlights the potential hazards and consequences of peripheral nerve injuries on an ICU setting in COVID-19 patients, as well as the importance of a multidisciplinary approach for an early diagnosis and treatment, which are directly related to a better prognosis.

•

In an intensive care unit, neurological complications are frequently encountered.

•

CRPS may occur after peripheral nerve injuries, leading to increased disability.

•

The systemic hyperinflammation of severe COVID-19 may contribute to neuronal sensitization.

•

Peripheral and central neuronal sensitization can lead to chronical and disproportionate pain.

•

A multidisciplinary approach is important in prompt diagnosis and treatment.

Determining the credibility, accuracy and comprehensiveness of websites educating consumers on complex regional pain syndrome accessible in Australia: a systematic review

Complex regional pain syndrome (CRPS) is a distressing and disabling pain condition. Many people with CRPS and the health professionals who treat them seek information about the condition via the Internet. The credibility, accuracy and comprehensiveness of online CRPS information remains unknown. The aim of this study was to determine the credibility, accuracy and comprehensiveness of information presented on freely accessible websites that aim to educate people about CRPS. Keyword searches were conducted on the Australian Google site, with 'trustworthy' websites included and critically appraised. Primary outcomes were recognised metrics of credibility (JAMA benchmark credibility criteria) and website accuracy (according to European CRPS guidelines). Comprehensiveness was assessed using the proportion of European CRPS guidelines covered by the websites. In all, 30 websites with 819 recommendations were critically appraised. Five (17%) websites met all credibility criteria; of the recommendations, 349 (43%) were accurate, 252 (31%) were inaccurate and 218 (26%) were unclear. For comprehensiveness, an average of 17% of general guidelines, 15% of therapeutic guidelines and 6% of medication/supplement guidelines were covered. Online information about CRPS available to Australians has low credibility, accuracy and comprehensiveness. Many website recommendations are inaccurate or unclear, and many websites endorse inappropriate treatments. There is an urgent need for accurate and comprehensive sources of CRPS information online.

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.

[Complex regional pain syndrome-An update]

Complex regional pain syndrome (CRPS) is a pain disorder that develops in the hands or feet after injury. Currently, two types are differentiated, CRPS I without and CRPS II with nerve lesions as well as with either an initially warm or an initially cold subtype, depending on the clinical symptoms. After trauma a certain amount of inflammatory reaction is considered physiological. In acute CRPS this inflammation persists for months and is maintained by diverse inflammatory mediators in peripheral tissue and in blood. This persisting inflammation leads to a sensitization of the nociceptive system, causes somatic cells to proliferate and gives rise to a disrupted endothelial function. The treatment concept aims to antagonize the pathophysiologic components and includes anti-inflammatory and analgetic treatment, mobilization and restoration of the sensorimotor function of the affected limb.

[Physical therapy in the treatment of complex regional pain syndrome]

The treatment of patients with complex regional pain syndrome (CRPS) takes place in an interdisciplinary and multimodal setting. Physical therapies represent a major treatment focus along with physiotherapy, occupational therapy, and analgetic treatments. This review explains their importance in current clinical practice and gives an impression of the evidence on different treatments including electrotherapy, neuromodulating procedures, manual lymphatic drainage, CO₂ applications and paraffin wax baths. As far as ascertainable from clinical experience and the scientific literature, treatment recommendations are presented in accordance with current guidelines.

Decreasing incidence of complex regional pain syndrome in the Netherlands: a retrospective multicenter study

Background:

Complex regional pain syndrome type I (CRPS) is a symptom-based diagnosis of which the reported incidence varies widely. In daily practice, there appears to be a decrease in incidence of CRPS after a distal radius fracture and in general.

Questions/purposes:

The aim of this study was to assess the trend in the incidence of CRPS after a distal radius fracture and in general in the Netherlands from 2014 to 2018.

Methods:

The incidence of CRPS after a distal radius fracture was calculated by dividing the number of confirmed cases of CRPS after distal radius fracture by the total number of patients diagnosed with a distal radius fracture. Medical records of these patients were reviewed. Hospital-based data were used to establish a trend in incidence of CRPS in general. A Dutch national database was used to measure the trend in the incidence of CRPS in the Netherlands by calculating annual incidence rates: the number of new CRPS cases, collected from the national database, divided by the Dutch mid-year population.

Results:

The incidence of CRPS after distal radius fracture over the whole study period was 0.36%. Hospital data showed an absolute decrease in CRPS cases from 520 in 2014 to 223 in 2018. National data confirmed this with a decrease in annual incidence from 23.2 (95% CI: 22.5–23.9) per 100,000 person years in 2014 to 16.1 (95% CI: 15.5–16.7) per 100,000 person years in 2018.

Conclusion:

A decreasing trend of CRPS is shown in this study. We hypothesize this to be the result of the changing approach towards CRPS and fracture management, with more focus on prevention and the psychological aspects of disproportionate posttraumatic pain.

Level of Evidence:

level 3 (retrospective cohort study).

Circulating microRNAs from the mouse tibia fracture model reflect the signature from patients with complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) often results from an initial trauma that later produces a disproportionate amount of pain. The mechanisms underlying CRPS have been studied using a tibia fracture model (TFM) in rodents because this model closely mimics symptoms and has several molecular correlates observed in patients with CRPS.

OBJECTIVE

Here, we determined whether the TFM has alterations in circulating microRNAs (miRNAs) and cytokines transported by small extracellular vesicles (sEVs) that faithfully model previously reported miRNA alterations from patients with CRPS.

METHODS

We isolated and characterized serum-derived sEVs from mice 3 weeks after fracture when symptoms such as pain hypersensitivity develop. Whole-transcriptome profiling was used to determine sEV miRNAs, and Bio-Plex Pro Mouse Cytokine 23-plex assay was used to measure cytokines. Differentially expressed miRNAs from TFM were compared with previously reported circulating miRNA alterations from patients with CRPS.

RESULTS

Although sEV cytokine levels were unchanged, there were significant changes in sEV miRNA profiles. Differentially expressed miRNAs from TFM sEVs significantly overlapped with those previously reported in patients with CRPS. Of the 57 sEV miRNAs dysregulated in the TFM, 30 were previously reported in patients with CRPS compared with healthy control donors both in sEVs and 23 in whole blood.

CONCLUSIONS

These findings enhance the validity of TFM as a model for CRPS and suggest that specific miRNA dysregulation may be a shared feature of CRPS and the TFM. These dysregulated miRNAs could help identify mechanistic targets or serve as biomarker candidates for both diagnosis and treatment responses in clinical trials.

Complex Region Pain Syndrome Following Shoulder Surgery

Purpose

To describe the clinical features, treatment, and outcomes in patients with complex region pain syndrome (CRPS) following shoulder surgeries.

Methods

Three patients were diagnosed with CRPS according to the Budapest criteria. Patients were followed up prospectively at regular intervals for a minimum of 2 years. Demographic data, clinical symptoms, physical examination findings, treatment received, and outcomes were collected and reported.

Results

The minimum time interval between surgery and diagnosis was 3 weeks (average, 8 weeks). The index procedures included 2 arthroscopic rotator cuff repairs and 1 open Latarjet. Neurologic pain, muscle spasms, hand and wrist swelling, and joint stiffness were seen in the shoulder, wrist, and hand, but the elbow was spared in all patients. Despite the use of multimodal treatment modalities, the symptoms were refractory to treatment for prolonged periods (range, 6-12 months). Hand and wrist symptoms took an average of 4 months longer than shoulder symptoms to improve. At the latest follow-up (range, 24-26 months), varying degrees of residual hand dysfunction, pain, and inability to make a fist or fully extend the fingers were noted in all 3 patients.

Conclusions

CPRS type 1 following shoulder surgery is a disabling condition with a long-protracted clinical course. CRPS can present as early as few weeks after shoulder surgery, with symptoms of neuropathic pain, spasm, and stiffness affecting the entire upper-extremity joints except the elbow. CRPS symptoms resolve earlier in the shoulder compared with the wrist and hand, with pain improving first, followed by recovery of motion and function. Residual stiffness affecting grip function is last to recover and can present up to 2 years after onset of symptoms. Although prompt recognition and multimodal approach are considered the mainstay of treatment, there is no gold standard treatment modality that can reproducibly alter the natural history of CRPS.

Level of Evidence

IV, therapeutic case series.

Spinal cord stimulation in severe cases of complex regional pain syndrome: A retrospective cohort study with long-term follow-up

BACKGROUND

Complex regional pain syndrome (CRPS) is a debilitating pain condition often resistant to standard treatment modalities. In these cases, spinal cord stimulation (SCS) can be an option, but the effect on CRPS remains disputed. We aimed to assess the long-term effect of SCS on CRPS.

METHODS

We retrospectively analysed 51 CRPS patients implanted with an SCS system at the University Hospitals in Aarhus or Odense, Denmark, with a median follow-up time of 4.4 years. Primary outcomes were pain intensity on a numeric rating scale (NRS) and the Patients' Global Impression of Change (PGIC). Secondary outcomes were patient satisfaction, work status, consumption of pain medication, the Major Depression Inventory (MDI), Pain Catastrophizing Scale (PCS) and quality of life (QoL) measured using the Short-Form Health Survey (SF-36). For each outcome measure, baseline data were compared to the latest collected data point.

RESULTS

A significant pain relief was found with a mean reduction in NRS score of 2.4 (95% CI: 1.7-3.0, p < 0.0001). 68.8% reported 'much improved' or 'very much improved' on the PGIC scale. 87.5% would choose SCS again for the same outcome. A significant beneficial impact was found on MDI score, PCS, SF-36 summary scores and consumption of tricyclic antidepressants, antiepileptic drugs and opioids. No statistical effect was found on work status.

CONCLUSION

Pain intensity, depression, pain catastrophizing, pain medication use and QoL were significantly improved after SCS implantation, with high patient satisfaction rates in CRPS patients. This study supports the continued use of SCS in the treatment of severe CRPS.

SIGNIFICANCE

This study presents detailed data from a large, well-characterized cohort of Danish CRPS patients treated with SCS, analyzing several outcome measures. The results serve to document SCS as an effective treatment for severe CRPS and expands the cumulative level of evidence in favor of its use. Additionally, analysis of preoperative patient characteristics suggests that SCS treatment should not be withheld in patients with a high degree of psychological distress or high consumption of analgesics.

Complex Regional Pain Syndrome: The Importance of Early Diagnosis

Complex regional pain syndrome (CRPS) is a potentially life-altering, neuropathic pain condition that often affects an extremity in response to surgery or even minor trauma. The pain is often disproportionate to the injury sustained or the surgical procedure performed-and it has been described as excruciating and unbearable. CRPS can result in irreversible, disabling changes in the affected limb. In some cases it has resulted in amputation or severe psychological issues. However, CRPS outcomes are generally more successful with early detection and treatment. This article presents an overview of CRPS and discusses the critical role nurses can play in recognizing the condition early, assisting with treatment, and providing psychological support.

[Occupational therapy for complex regional pain syndrome]

Occupational therapy, as a rehabilitative treatment is an essential part of multimodal therapy for complex regional pain syndrome (CRPS). The goals of the treatment and the methods vary greatly for this condition, because they are subject to the changing symptomatology. In some cases there are overlapping and synergistic treatment strategies with physiotherapy. For a positive treatment result it is important to implement occupational therapy early on and continuously during the course of the disease. This allows treatment methods, such as mental exercises or sensory exercises to improve the processing of pain-triggering perceptual stimuli at an early stage. Alongside the classical movement exercises and advice on aids, special treatment methods, such as mirror therapy, neurocognitive rehabilitation according to Perfetti or the graded exposure concept can also be beneficial for CRPS patients.

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.

The challenge of recognizing severe pain and autonomic abnormalities for early diagnosis of CRPS

OBJECTIVES

Complex regional pain syndrome (CRPS) is a disabling usually post-traumatic pain condition. International guidelines emphasize early diagnosis for treatment and improved outcome. Early intense and persistent pain along with features of autonomic dysfunction in the first week's post-injury are early warning signs for development of CRPS. We have previously reported a delayed diagnosis of CRPS. The main purpose of the present study was to investigate possible causes of a delayed diagnosis, with a special focus of recognition of risk factors.

METHODS

A total of 52 CRPS 1 (without detectable nerve damage) and CRPS 2 (with evidence of nerve lesion) patients were included in the study. When examined at OUS-Rikshospitalet, we retrospectively asked the patients on the development of pain and autonomic abnormalities from the time of the eliciting injury, performed a thorough clinical investigation with an emphasis on signs of autonomic failure and compared symptoms and clinical findings with such information in previous medical records. We also evaluated symptoms and signs according to the type of injury they had suffered.

RESULTS

Of a total of 52 patients (30 women and 22 men, mean age 39.0 years at the time of injury), 34 patients had CRPS type 1 (65.4%) and 18 CRPS type 2 (34.6%), 25 patients with pain in the upper and 27 in the lower extremity. A total of 35 patients (67.3%) were diagnosed with CRPS (following mean 2.1 years) prior to the investigation at OUS-Rikshospitalet (mean 4.86 years following injury). Mean time from injury to diagnosis was 33.5 months (SD 30.6) (2.8 years) for all patients. In retrospect, all 17 patients first diagnosed at OUS met the CRPS diagnosis at an earlier stage. All patients retrospectively reported intense pain (numeric rating scale > 7) from the time of injury with a large discrepancy to previous medical records which only stated intense pain in 29.4% of patients with CRPS type 1 and 44.4% of patients with CRPS type 2 within the first four months. While the patients reported an early onset of autonomic dysfunction, present in 67.3 and 94.2% of the patients within one week and one month, respectively, reports of autonomic abnormalities within the first four months was far less (maximum in 51.7% of patients with CRPS type 1 and in 60% in CRPS 2). In 10 patients with CRPS type 1, no symptom nor sign of autonomic abnormalities was reported.

CONCLUSIONS

We still find a significant delay in the diagnosis of CRPS. There is a large discrepancy between both self-reporting of intense, disproportionate pain, as well as symptoms of autonomic abnormalities from the time of injury, and documentation in previous medical records. Our findings suggest a lack of awareness of risk factors for the development of CRPS, such as early intense pain and autonomic abnormalities without recovery, contributing to delayed diagnosis. The present results suggest causes of delayed CRPS-diagnosis. An increased attention to early warning signs/risk factors may improve diagnosis of CRPS.

The Role of Nonmedical Therapeutic Approaches in the Rehabilitation of Complex Regional Pain Syndrome

Purpose of the Review

Nonmedical therapeutic approaches are fundamental to the management of of Complex Regional Pain Syndrome (CRPS) in order to promote the best outcome for patients. This review focuses on three key approaches underpinning CRPS rehabilitation, namely, physiotherapy and occupational therapy, psychological approaches and education and self-management.

Recent Findings

Recently published European standards outline the quality of therapeutic care that people with CRPS must receive. Early initiated therapy is essential to optimise outcomes, underpinned by patient education. Therapists should promote early movement of the affected limb and encourage re-engagement with usual activities as immobilisation is known to have negative outcomes. There is evidence to support the possible long-term benefit of graded motor imagery and mirror therapy. Psychological assessment should include identification of depression and post-traumatic stress disorder, as treatment of these conditions may improve the trajectory of CRPS. Novel therapies include neurocognitive approaches and those addressing spatial bias, both of which should provide a focus for future research.

Summary

There exists a broad range of nonmedical therapeutic approaches to rehabilitation for CPRS that are thought to be important. However, the evidence for their efficacy is limited. Further research using standardised outcomes would be helpful in developing targeted therapies for the future.

Intramuscular Injection and Complex Regional Pain Syndrome Development After “Harmless” Procedures

Complex regional pain syndrome (CRPS) is a puzzling pain condition, typically occurring after trauma. Incidents as innocent as IV injection and vaccine administration may serve as the impetus for an as yet poorly understood cascade of neuro-inflammation and somatosensory changes. A condition with variable degrees of psychological involvement, disability, and purely clinical diagnostic criteria, the diagnosis is often significantly delayed before effective treatment is begun, decreasing the likelihood of success. A 58-year-old female initially presented with painless peripheral edema of the left arm without erythema or loss of function, with later bilateral development of multiple domains of symptoms consistent with CRPS. Plausible initiation events in this instance were an IV insertion in the left cubital fossa and vaccination into the right deltoid. Delay in diagnosis is common but utilization of the Budapest Criteria for diagnosis and prompt treatment improves outcomes.

Multiple Limb Involvement in a Severe Case of Complex Regional Pain Syndrome Treated With Spinal Cord Stimulation: A Case Report

Complex regional pain syndrome (CRPS) can be a debilitating, persistent, and treatment-resistant pain condition. This report presents a case of severe CRPS affecting multiple limbs, resistant to standard treatment modalities. Treatment with spinal cord stimulation (SCS) had an initial good effect. Nevertheless, the CRPS continued to progress, eventually affecting all 4 extremities. A lead fracture resulted in a rapidly developing recurrence of CRPS in the patient's arm, necessitating amputation. SCS may be an effective modality for treatment of severe CRPS. However, mechanical problems should always be considered when an SCS-implanted patient experiences rapid symptom progression or abrupt cessation of stimulation.

What is the incidence of complex regional pain syndrome (CRPS) Type I within four months of a wrist fracture in the adult population? A systematic review

Introduction

Complex regional pain syndrome (CRPS) is a severe chronic pain condition, the symptoms of which may develop following trauma to a limb. Despite wrist fracture being a common antecedent, estimates of the incidence of CRPS following this injury vary widely. Our objective was to establish the incidence of CRPS in adults within four months of a wrist fracture, using a systematic review of the literature published since 2010.

Methods

The databases MEDLINE, PubMed, EMBASE, PsychINFO, CINAHL, BNI and AMED were searched for observational studies reporting the incidence of CRPS following a wrist fracture. Inclusion criteria were the use of a validated diagnostic tool to assess for CRPS within four months of the fracture. Randomised controlled trials and clinical trials were excluded, as were data from patients with evidence of prior neurology. Incidence risk was then extracted or calculated. Included studies were assessed for methodological rigour using the Newcastle–Ottowa Scale for assessment of bias.

Results

Nine studies met the inclusion criteria. There was a high degree of heterogeneity in study populations including study setting, fracture management and diagnostic criteria. From the three studies with the highest methodological rigour we determined that the incidence risk of CRPS in adults is between 3.7% and 14% using the Budapest criteria, with an observation of lower rates in conservatively managed fractures.

Discussion

We found evidence that the reported incidence of CRPS is influenced by choice of diagnostic criteria, along with the study location and/or how the fracture is managed.

Prednisone for Acute Complex Regional Pain Syndrome: A Retrospective Cohort Study

Objective

The objective of this study was to evaluate prednisone effectiveness on complex regional pain syndrome (CRPS) features in a community-based outpatient rehabilitation setting.

Design

A single-centre, retrospective inception cohort design was used. Inclusion criteria were CRPS diagnosis according to the Budapest criteria, involvement of multiple joints, treatment with prednisone, and duration of symptoms less than one year. Typical prednisone treatment was 28-day taper regimen with 60 mg. Patient symptoms and signs were compared before and after treatment.

Results

There were 39 patients who met inclusion criteria for analysis. Duration of symptoms before treatment was 80.8 ± 67.7 days. Following treatment, 19 (48.7%) patients reported complete pain resolution, 19 (48.7%) patients reported decreased pain permitting functional use, and 1 (2.6%) patient reported no improvement. All symptoms and signs decreased significantly following oral prednisone treatment (p < 0.001). Range of motion (ROM) deficits persisted in 19 (49%) patients. However, 17 of these patients reported functional ROM recovery. Degree of ROM recovery and time-to-treatment had low positive correlation (r = 0.354, p < 0.001). Range of motion (ROM) deficits persisted in 19 (49%) patients. However, 17 of these patients reported functional ROM recovery. Degree of ROM recovery and time-to-treatment had low positive correlation (.

Conclusions

These data support short-course prednisone treatment for acute and subacute CRPS with multijoint involvement in a community rehabilitation setting. The association between time-to-treatment and ROM recovery suggests earlier treatment may result in improved ROM outcomes.

A medical mystery of complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a condition of neuropathic pain, which is characterized by significant autonomic and inflammatory features. CRPS occurs in patients who have limb surgery, limb fractures, or trauma. Many patients may have pain resolve within twelve months of the inciting incident; however, a small subset progresses to the chronic form. This transitional process often happens by changing from warm CRPS with dominant inflammatory phase to cold CRPS, in which autonomic characteristics or manifestations dominate. Several peripheral and central mechanisms are involved, which might vary among individuals over a period of time. Other contributors include peripheral and central sensitization, autonomic alterations, inflammatory and immune changes, neurochemical changes, and psychological and genetic factors. Although effective management of the chronic CRPS form is often challenging, there are a few high quality randomized controlled trials that support the efficacy of the most commonly used therapeutic approaches.

Influence of vitamin C on the incidence of CRPS-I after subacromial shoulder surgery

PURPOSE

The primary aim of this study was to determine whether postoperative administration of vitamin C (VC) is associated with reduced risk of complex regional pain syndrome type I (CRPS-I) after subacromial shoulder surgery (SaSS). The secondary objective of the study was to identify risk factor for the development of CRPS-I after SaSS.

MATERIALS AND METHODS

A retrospective cohort study was performed to evaluate 542 patients undergoing SaSS from January 2015 to December 2016. The cohort was divided into two groups based on VC administration [Group I (no VC) and Group II (500 mg/day oral VC for 50 days postoperatively)]. The relationship between VC administration and development of CRPS-I was assessed. Demographics, preoperative clinical parameters, and operative variables were evaluated to determine their effect on the incidence of CRPS-I.

RESULTS

A total of 267 patients (Group II) undergoing SaSS received VC, and 266 patients (Group I) did not. The incidence of CRPS-I was significantly different between two groups (36(13%) vs 18(7%), p = 0.009). Multivariable regression, however, demonstrated that VC reduced the risk of CRPS-I after SaSS by > 50% (aOR = 0.49; 95% CI 0.27-0.91). Patients undergoing open surgery (aOR = 2.19; 95% CI 1.2-4.0) were more likely to develop CRPS-I postoperatively. Higher preoperative Constant score (aOR = 0.94; 95% CI 0.91-0.98) was associated with lower risk for CRPS-I development.

CONCLUSIONS

The present study found that VC administered prophylactically for 50 days postoperatively is effective in preventing CRPS-I development after SaSS. CRPS-I is a common complication following SaSS, especially in the setting of an open approach. The authors recommend preventive management with VC and arthroscopic approaches when possible for SaSS.

LEVEL OF EVIDENCE III

Retrospective comparative study.