Are you better? A multi-centre study of patient-defined recovery from Complex Regional Pain Syndrome

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.

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

ABSTRACT

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

Beyond the case numbers: Social determinants and contextual factors in patient narratives of recovery from COVID-19

OBJECTIVE

This study aimed to describe and contextualise COVID-19 recovery from the perspective of patient-lived experience, to inform the evolving public health response to the pandemic.

METHODS

Narrative interviews were completed with 37 adult Australians between six and 10 months following their COVID-19 diagnosis. Verbatim transcripts were analysed thematically and trustworthiness was supported by multiple strategies to ensure rigour.

RESULTS

Three themes were identified: 1) trajectories of recovery, 2) back to 'some sort of normal' and 3) the importance of work. Resumed participation in activities of daily life, the influence of social determinants of health and the impact of contextual factors were prominent features in the recovery narratives.

CONCLUSIONS

The COVID-19 pandemic presents both challenges and opportunities for public health systems to formulate appropriate responses and make improvements. Behind the case numbers, patient narratives described the uncertainty, diversity and multiple pathways to recovery that need to inform public health policy.

IMPLICATIONS FOR PUBLIC HEALTH

Looking beyond the case numbers reveals a complex landscape characterised by uncertainty, diversity and multiple pathways to recovery. The pandemic presents challenges and opportunities for public health in Australia and New Zealand, lived experience expertise is crucial to the formulation of an effective response.

Molecular and clinical markers of pain relief in complex regional pain syndrome: An observational study

BACKGROUND

Complex regional pain syndrome (CRPS) is marked by disproportionate pain after trauma. Whilst the long-term outcome is crucial to patients, predictors or biomarkers of the course of pain or CRPS symptoms are still lacking. In particular, microRNAs, such as miR-223, decreased in CRPS, have been described only in cross-sectional studies.

METHODS

In this study, we characterised CRPS patients over a course of 2.5 years of standard treatment. The patient underwent clinical examination including pain measurement, symptom questionnaires, quantitative sensory testing (QST) and blood sampling. Exosomal microRNA levels were measured via qPCR. After follow-up, patients were stratified into 'pain relief' (mean pain reduced by ≥2 numeric rating scale) or 'persistence' (mean pain unchanged or worsened). The primary outcome was miR-223 and miR-939 expression, secondary outcomes were differences in clinical parameters between groups and time points.

RESULTS

Thirty-nine patients were included, 33 of whom qualified for stratification. Overall, patients reported lower pain and improved clinical characteristics after 2.5 years, but no significant changes in QST or miR-223 and miR-939 expression levels. 16 patients met the criteria for pain relief. This was associated with stable exosomal miR-223 expression, whilst levels further decreased in pain persistence. Clinically, pain relief was marked by shorter disease duration and correlated positively with high initial pain.

CONCLUSION

We identified progressively reduced miR-223 as a putative biomarker of chronic CRPS pain. Clinically, this study underlines the importance of early diagnosis and treatment showing that high initial pain does not predict an unfavourable outcome. Finally, pain relief and recovery of sensory disturbances seem independent processes.

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.

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.

Complex regional pain syndrome what is the outcome? - a systematic review of the course and impact of CRPS at 12 months from symptom onset and beyond

Background and Objective

To improve CRPS treatment, it is imperative to understand the nature, degree and relative importance of ongoing problems associated with CRPS. The objective of this systematic review was to summarize the published data concerning measures of function and impact including occupational parameters, of CRPS at 12 months from symptom onset and beyond.

Databases and Data Treatment

MEDLINE, EmBase and PsychINFO were searched (inception to May 2021). Study cohorts were eligible if they included; adult patients with the primary complaint of CRPS ≥12 months duration, outcomes that reported change in CRPS signs and symptoms, and physical and social function. Prospero registration: CRD42021241785.

Results

Twenty‐two included studies suggest that pain and motor dysfunction are the most dominant long‐term features of CRPS, persisting for 51%–89% of patients at ≥12 months. On average for all patients who had CRPS at baseline, grip strength was found to be reduced by 25%–66%, and range of motion reduced by 20%–25% at ≥12 months. Such losses were associated with physical and social disability. Thirty to forty percent of all patients did not return to work and a further 27%–35% of persons returned to work but required some form of workplace adaptation, although the quality of this data was poor. Quality assessment highlighted limitations in the literature, such as high attrition bias and variations in diagnostic criteria.

Conclusions

Results provide first‐time quantitative data including specific evidence about losses to motor function and long‐term compromises to work status. Results demonstrate that the ongoing impact of one episode of CRPS on limb function and work status is relatively high.

Significance

This review provides first‐time clarity in relation to outcomes of limb function and work status associated with an episode of CRPS, beyond 12 months from onset. Results demonstrate that the long‐term impact of an episode of CRPS on these outcomes is much larger than previously described, and thus also illustrates how the wider health economic impact of CRPS is not yet fully understood. We additionally highlight the need for future research that identifies long‐term predictors, and treatments that can foster good functional and occupational recovery.

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.

Exploring peoples' lived experience of complex regional pain syndrome in Australia: a qualitative study

OBJECTIVES

Complex regional pain syndrome (CRPS) is a persistent pain condition which is often misunderstood and poorly managed. Qualitative studies are needed to explore the lived experience of the condition and to better understand patient perspectives on their management experiences and needs. The aim of this study was to explore the lived experience of CRPS in Australia, including exploration of their perceptions of care and advice received from healthcare professionals.

METHODS

A qualitative study with individual in-depth semi-structured, face-to-face interviews was performed (n=15, 80% female, average time elapsed since diagnosis 3.8 years). Qualitative data were analysed using an inductive thematic analysis approach.

RESULTS

Four main themes with associated subthemes were identified, representing the participants' journey: (1) Life Changing Impact of CRPS (Subthemes: Impact on self, Impact on others); (2) Variable Experiences of Care (Subthemes: Helpful experiences of care, Unhelpful experiences of care); (3) Making Sense of CRPS (Subthemes: Knowledge and understanding, Dealing with unpredictability); and (4) Perceptions on Lessons Learned from Living with CRPS (Subthemes: Acceptance was an important part of the journey, Trial and error was necessary to find an individual way forward, Coping strategies).

CONCLUSIONS

The themes identified align to and expand on prior qualitative research findings in people with CRPS. It highlights the challenges people face related to their personal self, their close relationships and their social and work roles. It highlights the difficulties these people have in finding reliable, trust-worthy information. These findings suggest that healthcare professionals may benefit from education about how to better support people with CRPS, including helping people to navigate to the right care. Engaging people with CRPS in the development of educational resources should be a future research goal. It is recommended that patient perspectives are incorporated into the development of care pathways for CRPS.

Prognostic Factors in Complex Regional Pain Syndrome Type 1 Occurring in the Korean Army

OBJECTIVES

In Korea, patients diagnosed with complex regional pain syndrome (CRPS) in the army are typically discharged from the army; however, the course of the disease after discharge is not known. The purpose of this study was to investigate the course of CRPS that occurred in the army and to identify the influences of various clinical and psychosocial factors immediately before discharge on the disease course.

METHODS

Clinical profiles and psychosocial status were collected from the medical records of 16 patients with CRPS type 1 who were discharged during the period between March 2017 and April 2018. The degree of improvement after discharge was assessed by follow-up evaluation through telephone contact. Cox proportional hazards regression was performed to identify clinical and psychosocial predictors for the rate of recovery.

RESULTS

The median time to recovery after discharge was 39 weeks (95% confidence interval [CI] = 8.8-69.2 weeks). The sole predictor for time to recovery after discharge was the time period from the onset of pain to discharge. Each one-week increase in the duration of pain experienced in the military was associated with a 18.2% (95% CI = 5.3%-29.5%) reduction in the rate of recovery after discharge (P = 0.007).

CONCLUSIONS

Patients who experienced a short period of pain in the military demonstrated a relatively good prognosis after discharge. This may show how prolonged pain in the army could affect the experience of pain from a social point of view, in that it shows the disease course after a change in the social environment.

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.

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

TRIAL REGISTRATION

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

The long-term effect of complex regional pain syndrome type 1 on disability and quality of life after foot injury

PURPOSE

To study the long-term evolution of patients with lower-limb Complex Regional Pain Syndrome (CRPS), focusing on functional and proprioceptive aspects and quality of life.

METHODS

In 20 patients suffering from chronic distal lower-limb CRPS diagnosed using Budapest criteria, we assessed joint position sense and strength of the knee muscles at the CRPS and unaffected leg, functional exercise capacity, pain, CRPS severity score, quality of life and kinesiophobia. Similar assessments were performed in 20 age-matched controls.

RESULTS

The joint position performance (at 45°) was significantly lower for the CRPS leg as compared to controls. The knee extensor strength of the CRPS leg was significantly reduced as compared to the unaffected leg (-27%) and controls (-42%). CRPS patients showed significantly reduced performance at the 6 min-walk test as compared to their age group predicted value and controls. Patients suffering from CRPS for 3.8 years in average still exhibit high pain, severity and kinesiophobia scores.

CONCLUSIONS

Long-term deficits in strength and proprioceptive impairments are observed at the knee joint of the CRPS leg. This persistent functional disability has significant repercussions on the quality of life. We highlight the importance of including strength and proprioceptive exercises in the therapeutic approaches for CPRS patients.IMPLICATIONS FOR REHABILITATIONThe long-term evolution of patients suffering from lower-limb Complex Regional Pain Syndrome is associated with persistent disability, pain and impacts the quality of life.Strength, proprioceptive, functional and subjective assessments are necessary to better identify deficits.Rehabilitation should focus on the overall deficit of the affected and contralateral limb.

Pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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