The association between psychological factors and the development of complex regional pain syndrome type 1 (CRPS1)--a prospective multicenter study

Mechanisms of complex regional pain syndrome

Complex Regional Pain Syndrome (CRPS) is a chronic pain disorder characterized by a diverse array of symptoms, including pain that is disproportionate to the initial triggering event, accompanied by autonomic, sensory, motor, and sudomotor disturbances. The primary pathology of both types of CRPS (Type I, also known as reflex sympathetic dystrophy, RSD; Type II, also known as causalgia) is featured by allodynia, edema, changes in skin color and temperature, and dystrophy, predominantly affecting extremities. Recent studies started to unravel the complex pathogenic mechanisms of CRPS, particularly from an autoimmune and neuroimmune interaction perspective. CRPS is now recognized as a systemic disease that stems from a complex interplay of inflammatory, immunologic, neurogenic, genetic, and psychologic factors. The relative contributions of these factors may vary among patients and even within a single patient over time. Key mechanisms underlying clinical manifestations include peripheral and central sensitization, sympathetic dysregulation, and alterations in somatosensory processing. Enhanced understanding of the mechanisms of CRPS is crucial for the development of effective therapeutic interventions. While our mechanistic understanding of CRPS remains incomplete, this article updates recent research advancements and sheds light on the etiology, pathogenesis, and molecular underpinnings of CRPS.

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.

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.

Person-centred management of upper limb complex regional pain syndrome: an integrative review of non-pharmacological treatment

Introduction

Complex Regional Pain Syndrome (CRPS) is most common in the upper limb and associated with high disability. The purpose of this review was to critically appraise and synthesise literature exploring non-pharmacological treatment for upper limb CRPS, to guide upper-limb-specific management.

Methods

Using an integrative review methodology, 13 databases were searched to identify all published studies on non-pharmacological management of upper limb CRPS. The Crowe Critical Appraisal Tool was used to provide quality ratings for included studies, and analysis employed a qualitative descriptive approach.

Results

From 236 abstracts reviewed, 113 full texts were read, and 38 articles selected for data extraction. Designs included single case (n = 14), randomised controlled trial (n = 8), prospective cohort (n = 8), case series (n = 4), retrospective (n = 3), and mixed methods (n = 1). Interventions were categorised as sensory retraining (n = 13), kinesiotherapy (n = 7), manual therapies (n = 7), physical modalities (n = 6), and interdisciplinary treatment programmes (n = 5). All studies measured pain intensity, and most (n = 24) measured physical parameters such as strength, movement, or perceptual abilities. Few measured patient-rated function (n = 13) or psychological factors (n = 4). Quality ratings ranged from 30% to 93%, with a median of 60%.

Conclusion

Methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor. Movement, desensitisation, and graded functional activity remain the mainstays of intervention. However, despite the impact of CRPS on wellbeing and function, psychological factors and functional outcomes are infrequently addressed. Further robust research is required to determine which aspects of treatment have the greatest influence on which symptoms, and when and how these should be introduced and progressed.

Factors associated with disability and pain intensity in patients with complex regional pain syndrome

PURPOSE

To examine the associations between psychological factors (pain catastrophizing, pain-related anxiety, and fear of pain) and level of pain and disability in patients with complex regional pain syndrome (CRPS).

METHODS

One hundred and two patients with CRPS were recruited from tertiary care centers with the different upper limb injuries were evaluated for pain, disability, and psychological factors. Patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire, Patient Rated Wrist Evaluation (PRWE), Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia (TSK-11), and Depression, Anxiety, and Stress Scale (DASS). The associations of pain and disability with presence of these behavioral and mental health factors were examined using bivariate and multivariable analyses. These models were adjusted for age, sex, injured dominant hand, and previous surgery.

RESULTS

A higher pain catastrophizing score (β = 0.55, p = 0.00) was associated with greater disability. A higher pain catastrophizing score (β = 0.35, p = 0.001) and female gender (β = 0.24, p = 0.01) were associated with greater pain at rest (PAR). A higher pain catastrophizing score and having a surgical history were associated with greater pain with movement (β = 0.25, p = 0.02). Scores of ≥18.5 in PCS, ≥57.5 on TSK, and ≥15.5 on DASS were associated with higher risk of experiencing pain and disability.

CONCLUSIONS

Pain catastrophizing, female sex, and surgical intervention are associated with poor outcomes. Physiologic, psychological factors, and treatment factors interact to influence outcomes. The results of this study further validate the associations of chronic pain and disability with pain catastrophizing in patients with CRPS. The novel finding of this study is introducing cut-off scores for TSK, PCS, and DASS as a screening tool to predict pain, functional limitations.Implication for rehabilitationPain catastrophizing has a vital role in the magnitude of disability and pain in patients with CRPS.The novel finding of this paper was the cut-off scores on the psychological evaluations that can enable using them as screening tool for bad outcomes in patients with CRPS.Cut off scores from different psychological evaluations can be used as a yellow flag for clinician's for detecting patients with increased risk of pain and disability.The identification of a cut-off can also have implications for implementing change in clinical practice by identifying the need for early and intensive interventions.

Preoperative Predictors of Complex Regional Pain Syndrome Outcomes in the 6 Months Following Total Knee Arthroplasty

This prospective observational study evaluated preoperative predictors of complex regional pain syndrome (CRPS) outcomes in the 6 months following total knee arthroplasty (TKA). Participants were n = 110 osteoarthritis patients (64.5% female) undergoing unilateral TKA with no prior CRPS history. Domains of negative affect (depression, anxiety, catastrophizing), pain (intensity, widespread pain, temporal summation of pain [TSP]), pain interference, sleep disturbance, and pro-inflammatory status (tumor necrosis factor-alpha [TNF-a]) were assessed preoperatively. CRPS outcomes at 6-week and 6-month follow-up included the continuous CRPS Severity Score (CSS) and dichotomous CRPS diagnoses (2012 IASP criteria). At 6 months, 12.7% of participants met CRPS criteria, exhibiting a "warm CRPS" phenotype. Six-week CSS scores were predicted by greater preoperative depression, anxiety, catastrophizing, TSP, pain intensity, sleep disturbance, and TNF-a (P's < .05). Provisional CRPS diagnosis at 6 weeks was predicted by higher preoperative TSP, sleep disturbance, and TNF-a (P's < .05). CSS scores at 6 months were predicted by more widespread and intense preoperative pain, and higher preoperative TSP, pain interference, and TNF-a (P's < .01). CRPS diagnosis at 6 months was predicted only by more widespread and intense pain preoperatively (P's < .05). Risk for CRPS following TKA appears to involve preoperative central sensitization and inflammatory mechanisms. Preoperative negative affect is unlikely to directly influence long-term CRPS risk. PERSPECTIVE: This article identifies preoperative predictors of CRPS features at 6 months following total knee arthroplasty, including more widespread pain and higher pain intensity, temporal summation of pain, pain interference, and tumor necrosis factor-alpha levels. Findings suggest the importance of central sensitization and inflammatory mechanisms in CRPS risk following tissue trauma.

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.

Relative Prevalence and Associated Factors of Complex Regional Pain Syndrome Type I in Patients with Radial Head Fractures Treated with Open Reduction and Internal Fixation: A Cross-Sectional Study

Objective

This cross-sectional study aimed to examine the incidence and associated factors of complex regional pain syndrome type I (CRPS I) in patients who underwent open reduction and internal fixation (ORIF) for radial head fractures.

Methods

The study enrolled 601 radial head fracture patients treated with ORIF, 523 of which completed the 1-year follow-up. The incidence of CRPS I in those patients was assessed using the Budapest criteria. Patients were then divided into 2 groups: patients with CRPS I (n = 28) and patients without CRPS I (n = 495). The patients' demographic and clinical data before the operation were prospectively collected by our team. Independent t-tests and χ² tests were used as univariate analyses to compare the demographic and clinical data between the two groups. Meanwhile, multivariate regression analysis was conducted to identify the associated risk factors for CRPS I.

Results

The incidence of CRPS I in patients with radial head fractures treated with ORIF was 5.5% during the first year following surgery. Significant differences were observed in age, gender, type of trauma, modified Mason Classification, and depressive personality disorders. The logistic regression analysis revealed that the female gender, modified Mason type III fractures, and depressive patients were significantly more likely to develop CRPS I (p=0.021, 0.023, and 0.025, respectively).

Conclusions

The incidence of CRPS I among radial head fracture patients undergoing ORIF was 5.5%. In addition, early detection of CRPS I and providing adequate intervention will likely result in greater benefits for those patients.

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

OBJECTIVE

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

SUBJECTS

Forty-eight people with CRPS participated in this research.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Denying the Truth Does Not Change the Facts: A Systematic Analysis of Pseudoscientific Denial of Complex Regional Pain Syndrome

Purpose

Several articles have claimed that complex regional pain syndrome (CRPS) does not exist. Although a minority view, it is important to understand the arguments presented in these articles. We conducted a systematic literature search to evaluate the methodological quality of articles that claim CRPS does not exist. We then examined and refuted the arguments supporting this claim using up-to-date scientific literature on CRPS.

Methods

A systematic search was conducted in MEDLINE, EMBASE and Cochrane CENTRAL databases. Inclusion criteria for articles were (a) a claim made that CRPS does not exist or that CRPS is not a distinct diagnostic entity and (b) support of these claims with subsequent argument(s). The methodological quality of articles was assessed if possible.

Results

Nine articles were included for analysis: 4 narrative reviews, 2 personal views, 1 letter, 1 editorial and 1 case report. Seven points of controversy were used in these articles to argue that CRPS does not exist: 1) disagreement with the label “CRPS”; 2) the “unclear” pathophysiology; 3) the validity of the diagnostic criteria; 4) CRPS as a normal consequence of immobilization; 5) the role of psychological factors; 6) other identifiable causes for CRPS symptoms; and 7) the methodological quality of CRPS research.

Conclusion

The level of evidence for the claim that CRPS does not exist is very weak. Published accounts concluding that CRPS does not exist, in the absence of primary evidence to underpin them, can harm patients by encouraging dismissal of patients’ signs and symptoms.

[Effectiveness of inpatient interdisciplinary multimodal pain therapy (IMPT) in patients with complex regional pain syndrome (CRPS) : A retrospective study]

BACKGROUND

The primary symptom of complex regional pain syndrome (CRPS) is pain. Interdisciplinary multimodal pain therapy (IMPT) is the gold standard of treatment. The purpose of this study was to identify the beneficial effect of inpatient IMPT on pain level, sensation, perception and impairment in patients with CRPS.

QUESTION

The aim of the present study was to examine the effect of full-term IMPT on pain intensity, pain perception, pain processing, and pain impairment in patients with CRPS.

METHODS

In 265 patients with CRPS, pain level was retrospectively assessed by the numeric rating scale for pain (NRS), the Pain Perception Scale (SES) and the Pain Management Questionnaire (FESV) at the beginning and end of IMPT.

RESULTS

There was a significant reduction in the average and highest pain level on the NRS, a significant improvement in the affective experience of pain and cognitive pain management, as well as pain-related mental impairment. All patients improved significantly in resting and relaxation techniques. With regard to pain-related helplessness and depression, patients with mental comorbidity benefitted most. Patients undergoing invasive procedures in the form of peripheral nerve blockage showed no significantly improved outcome with regard to the tested parameters.

DISCUSSION

The current study demonstrated that IMPT has a highly beneficial effect on the level, experience and processing of pain in patients with CRPS.

Impact of adolescent complex regional pain syndrome on the psychopathology of young men ahead of military service: a retrospective cohort analysis of Korean conscription data

BACKGROUND

The relationship between physical and psychopathological features in complex regional pain syndrome (CRPS) has been a subject of constant interest, but no data are available in adolescents. Therefore, we aimed to identify the factors associated with psychopathology in adolescents with CRPS ahead of military service.

METHODS

We retrospectively reviewed all conscription examinees who had completed a Military Personality Inventory (MPI) during a period between February 2013 and December 2016. A total of 63 persons with a history of CRPS (19-years of age for all) were enrolled. Basic demographic and pain-related data were analyzed to examine their association with MPI results. The mean FGR score as well as the 8 subdomain scores were compared between those with pain duration at < 15 months (n = 30) versus ≥15 months (n = 33). Binary MPI results (normal-abnormal) were also compared between the two groups.

RESULTS

In multivariate analysis, abnormal MPI was associated with pain duration, with an odds ratio (OR) at 1.05 for every 1-month increase (95% confidence interval (CI) 1.02-1.08; P = 0.002). Subjects with pain duration at ≥15 months have lower faking good response score (P < 0.001 vs. those with pain duration at < 15 months), and higher abnormal MPI result rate, faking bad response, inconsistency, anxiety, depression, somatization, paranoid, personality disorder cluster A, and personality disorder cluster B scores (P < 0.05). Pain duration was significantly associated with the MPI variables.

CONCLUSIONS

Pain duration is associated with psychopathology in adolescents with CRPS. Psychopathologic features increased as the disease duration increased. A comprehensive understanding of time-dependent psychopathological factors could support the planning of multimodal approaches for managing adolescent CRPS.

Psychiatric Comorbidity and Complex Regional Pain Syndrome Through the Lens of the Biopsychosocial Model: A Comparative Study

PURPOSE

To compare the prevalence of psychiatric comorbidity between patients with complex regional pain syndrome (CRPS) of the hand and non-CRPS patients and to assess the association between biopsychosocial (BPS) complexity profiles and psychiatric comorbidity in a comparative study.

PATIENTS AND METHODS

We included a total of 103 patients with CRPS of the hand and 290 patients with chronic hand impairments but without CRPS. Psychiatric comorbidities were diagnosed by a psychiatrist, and BPS complexity was measured by means of the INTERMED. The odds ratios (OR) of having psychiatric comorbidities according to BPS complexity were calculated with multiple logistic regression (adjusted for age, sex, and pain).

RESULTS

Prevalence of psychiatric comorbidity was 29% in CRPS patients, which was not significantly higher than in non-CRPS patients (21%, relative risk=1.38, 95% CI: 0.95 to 2.01 p=0.10). The median total scores of the INTERMED were the same in both groups (23 points). INTERMED total scores (0-60 points) were related to an increased risk of having psychiatric comorbidity in CRPS patients (OR=1.46; 95% CI: 1.23-1.73) and in non-CRPS patients (OR=1.21; 95% CI: 1.13-1.30). The four INTERMED subscales (biological, psychological, social, and health care) were correlated with a higher risk of having psychiatric comorbidity in both groups. The differences in the OR of having psychiatric comorbidity in relation to INTERMED total and subscale scores were not statistically different between the two groups.

CONCLUSION

The total scores, as well as all four dimensions of BPS complexity measured by the INTERMED, were associated with psychiatric comorbidity, with comparable magnitudes of association between the CRPS and non-CRPS groups. The INTERMED was useful in screening for psychological vulnerability in the two groups.

Are Illness Perceptions Associated with Pain and Disability in Complex Regional Pain Syndrome? A Cross-Sectional Study

Objective

Complex regional pain syndrome (CRPS) is a complex and often poorly understood condition, and people with CRPS will have diverse beliefs about their symptoms. According to the self-regulation model, these beliefs (termed “illness perceptions”) influence health behaviors and outcomes. Previous studies have found that psychological factors influence CRPS outcomes, but few studies have investigated CRPS patients’ illness perceptions specifically. The present study examined whether illness perceptions were related to pain intensity and other relevant outcomes in people with CRPS.

Methods

In this cross-sectional study, 53 patients with CRPS (type 1 and type 2) completed questionnaires assessing illness perceptions, pain, disability, and psychological factors. Multiple regression analyses were used to determine whether illness perceptions were associated with pain intensity, disability, depression, and kinesiophobia, after controlling for possible covariates (including clinical and demographic factors, pain catastrophizing, and negative affect).

Results

Negative illness perceptions were associated with greater pain, disability, and kinesiophobia, but not depression. Specifically, attributing more symptoms to CRPS (more negative illness identity perceptions) was associated with greater pain intensity, and reporting a poorer understanding of CRPS (lower illness coherence scores) was associated with greater disability and kinesiophobia.

Conclusions

Patients with CRPS with more negative illness perceptions (particularly perceptions indicating a poor understanding of their condition) also experience greater pain, disability, and kinesiophobia. Future research could investigate whether altering CRPS patients’ illness perceptions influences clinical outcomes.

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.

Complex regional pain syndrome: A rare but potentially disabling complication of transradial cardiac catheterization

BACKGROUND

Chronic Regional Pain Syndrome (CRPS) is a rare complication following transradial cardiac catheterization.

AIMS

To discuss the clinical features, pathophysiology, diagnosis and management of CRPS.

METHODS

Literature review performed.

RESULTS

CRPS is seen rarely in the literature following upper limb arterial access for coronary procedures, which may be due to a low incidence of the syndrome as well as limited recognition and underreporting.

DISCUSSION

The diagnosis and management of CRPS are discussed in detail.

CONCLUSION

If CRPS is a potential diagnosis then prompt early referral to a center with a specialist interest in CRPS is recommended. Prompt diagnosis and early commencement on the correct patient treatment pathway are essential, to avoid potentially life changing disability and the psychological consequences of living with intractable chronic undiagnosed pain.

Psychological, social and biological correlates of body perception disturbance in complex regional pain syndrome

Body Perception Disturbance (BPD) in Complex Regional Pain Syndrome (CRPS) still represents a poorly understood phenomenon. Research has shown that knowledge about changes in body perception can yield relevant information for understanding and treating the disease. This study addressed possible connections between BPD and psychological and social factors, pain intensity, and disease duration. Sixty patients with chronic CRPS Type I of the hand were recruited. Body Perception Disturbance was assessed using the Galer and Jensen Neurobehavioral Questionnaire (GJ) and the BATH CRPS Body Perception Disturbance Scale (BATH). Depression, anxiety, stress, childhood trauma and other life events were assessed using standardized and validated questionnaires. This study found that BPD in CRPS was significantly correlated with measures of depression, anxiety, current stress, quality of life, and pain intensity, but not with stress experienced in the twelve months preceding onset of illness, childhood trauma, or duration of illness. Future research needs to identify which patients are most likely to develop these psychological conditions of CRPS, so that early, preventive intervention is possible. This study establishes a relationship between depression, anxiety, current stress, quality of life, pain intensity, and BPD severity. It also supports literature suggesting that preexisting stress, childhood trauma, and disease duration have no influence on BPD. The findings suggest that there is a bidirectional influence between brain alterations, psychological symptoms, and illness severity.

Psychological Characteristics in Patients with Chronic Complex Regional Pain Syndrome: Comparisons with Patients with Major Depressive Disorder and Other Types of Chronic Pain

Objective

This study investigated psychological characteristics of patients with chronic complex regional pain syndrome (CRPS) and examined relationships between psychosocial factors and pain severity.

Methods

In total, 76 patients with CRPS, 95 patients with other types of chronic pain, 171 healthy controls, and 66 patients with major depressive disorder (MDD) were included. Minnesota Multiphasic Personality Inventory (MMPI-2) profiles and scores on the Beck Depression Inventory and State-Trait Anxiety Inventory were calculated. Pain intensity was measured using a visual analog scale (VAS).

Results

Patients with CRPS scored higher on the Hypochondriasis (Hs), Depression (D), Hysteria (Hy), Paranoia (Pa), and Psychasthenia (Pt) scales of the MMPI-2 compared to healthy controls. The CRPS group scored lower on the D, Psychopathic deviate (Pd), Pa, Pt, Schizophrenia (Sc), and Social introversion (Si) scales compared to the MDD group. Although CRPS patients reported higher levels of pain than patients with other types of pain, the MMPI profiles of the two pain groups did not differ significantly. Linear regression analyses revealed that pain severity was significantly associated with depression and scores on the Masculinity-Femininity (Mf) scale.

Conclusion

This is the first comparative study of the psychological characteristics of chronic CRPS patients, healthy controls, and patients with MDD. The neurotic profiles of CRPS patients were more psychologically adaptable than were those of patients with MDD; however, this profile was shared by both pain groups. The present findings further showed that, although pain severity was not a major contributor to depression, patients with CRPS should be evaluated for depressive symptoms.

Complex Regional Pain Syndrome: Current Diagnostic and Treatment Considerations

Complex Regional Pain Syndrome is a severe complication of extremity fracture or other injury. Patients who develop this show marked hyperalgesia and allodynia, altered vasomotor, sudomotor and trophic changes. The condition affects women more than men and is most common in those between the ages of 50 and 70 years but can be seen in younger athletes. The diagnosis is made clinically, and treatment is directed at functional recovery using medications, occupational and physical therapy, and psychological interventions. Prognosis for complete recovery is variable and unpredictable.

[Complex regional pain syndrome (CRPS) : An update]

The acute phase of complex regional pain syndrome (CRPS) is pathophysiologically characterized by an activation of the immune system and its associated inflammatory response. During the course of CRPS, central nervous symptoms like mechanical hyperalgesia, loss of sensation, and body perception disorders develop. Psychological factors such as pain-related anxiety and traumatic events might have a negative effect on the treatment outcome. While the visible inflammatory symptoms improve, the pain often persists. A stage adapted, targeted treatment could improve the prognosis. Effective multidisciplinary treatment includes the following: pharmacotherapy with steroids, bisphosphonates, or dimethylsulfoxide cream (acute phase), and antineuropathic analgesics (all phases); physiotherapy and behavioral therapy for pain-related anxiety and avoidance of movement; and interventional treatment like spinal cord or dorsal root ganglion stimulation if noninvasive options failed.

Complex Regional Pain Syndrome: An update

Complex regional pain syndrome (CRPS) is a perplexing painful syndrome of the extremities usually following a harmful event. It is distinguished in two types, mainly depending on the presence of nerve injury. Although its prevalence may vary depending on social and ethnic factors, middle-aged women seem to suffer most often and the upper limb is the most commonly affected extremity. Apart from pain, which is the dominating feature, the clinical picture unfolds across several domains: sensory, motor, autonomic and trophic. This syndrome develops in two phases, the acute (warm) phase, with the classic symptoms of inflammation, and the chronic (cold) phase, often characterized by trophic changes of the soft tissues and even bones. Although the syndrome has been studied for over two decades, no imaging or laboratory test has been established for the diagnosis and recently proposed diagnostic criteria have not yet been validated and are only occasionally applied. Its pathophysiology is still quite obscure, although the most likely mechanisms involve the classic and neurogenic paths of inflammation mediated by cytokines and neuropeptides, intertwined with changes of the autonomic and central nervous system, psychological mechanisms and, perhaps, autoimmunity. Although plenty of treatment modalities have been tried, none has been proven unequivocally efficacious. Apart from information and education, which should be offered to all patients, the most effective pharmacological treatments seem to be bisphosphonates, glucocorticoids and vasoactive mediators, while physical therapy and rehabilitation therapy also make part of the treatment.

Incidence of and Risk Factors for Complex Regional Pain Syndrome Type 1 after Surgery for Distal Radius Fractures: A Population-based Study

This study aimed to evaluate the incidence rates of and risk factors for complex regional pain syndrome type 1 (CRPS-1) after surgery for distal radius fractures (DRFs). Using data from January 2007 to December 2014, we analysed the data from the Korean Health Insurance Review and Assessment (HIRA) service. After extracting the data of patients aged ≥18 years whose diagnostic and operation codes for DRFs were entered into the HIRA database, we analysed the incidence rates of and risk factors for CRPS-1. From 2007 to 2014, 172,194 DRFs were treated surgically. Within 1 year postoperatively, 1,103 CRPS-1 cases were diagnosed, with an incidence of 0.64%. On univariate and multivariate analyses, the risk factors that significantly correlated with the incidence of CRPS-1 included female sex, rheumatoid arthritis, open reduction, open fracture, and accompanying ulnar fracture, whereas old age, psychiatric disease, and external fixation were not statistically significant. The incidence of CRPS-1 after surgery for DRF was very low (0.64%) in South Korea. Careful monitoring is necessary for patients with complex fractures and rheumatoid arthritis who are at increased risk of developing CRPS-1.

Psychosocial factors associated with poor outcomes after amputation for complex regional pain syndrome type-I

Background

Amputation for longstanding therapy resistant complex regional pain syndrome type-I (CRPS-I) is controversial. Reported results are inconsistent. It is assumed that psychological factors play a role in CRPS-I.

Objective

To explore which psychological factors prior to amputation are associated with poor outcomes after amputation in the case of longstanding therapy resistant CRPS-I.

Methods

Between May 2008 and August 2015, 31 patients with longstanding therapy resistant CRPS-I were amputated. Before the amputation 11 psychological factors were assessed. In 2016, participants had a structured interview by telephone and filled out questionnaires to assess their outcome. In case of a perceived recurrence of CRPS-I a physician visited the patient to examine the symptoms. Associations between psychological factors and poor outcomes were analysed.

Results

Four of the 11 psychological factors were associated with poor outcomes. Regression analyses showed that change in the worst pain in the past week was associated with poor social support (B = 0.3, 95% confidence interval: 0.1;0.6) and intensity of pain before amputation (B = 2.0, 95% confidence interval 0.9;3.0). Patients who reported important improvements in mobility (n = 23) had significantly higher baseline resilience (median 79) compared to those (n = 8) who did not report it (median 69)(Mann-Whitney U, Z = -2.398, p = 0.015). Being involved in a lawsuit prior to amputation was associated with a recurrence in the residual limb (Bruehl criteria). A psychiatric history was associated with recurrence somewhere else (Bruehl criteria).

Conclusion

Poor outcomes of amputation in longstanding therapy resistant CPRS-1 are associated with psychological factors. Outstanding life events are not associated with poor outcome although half of the participants had experienced outstanding life events.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Psychiatric Disorders in Complex Regional Pain Syndrome (CRPS): The Role of the Consultation-Liaison Psychiatrist

Background

Complex regional pain syndrome (CRPS) is a multifactorial disorder with complex aetiology and pathogenesis. At the outpatient pain clinic of Magdeburg University Hospital, all patients, without exception, are subject to permanent psychiatric care delivered by a consultation-liaison psychiatrist. In CRPS, psychological stabilization and treatment of the neuropathic aspects are equally important. The aim of this single-center retrospective study was to determine mental/psychiatric defects impairing pain processing at the time of investigation and show the effects of treating mental disorders and neuropathic pain with the same psychotropic drugs.

Method

On admission, the consultation-liaison psychiatrist examined the mental state of every patient in a semistructured interview according to AMDP (working group for methods and documentation in psychiatry). Due to the model of the Department of Anaesthesiology, we are able to compare the group of CRPS patients with all other outpatients treated for pain.

Results

The medical treatment of psychiatric dysfunction leads to an analgesic effect. Only every second CRPS patient had an additional psychiatric diagnosis, and 15.6% were diagnosed with depressive mood disorders and show a higher prevalence of depressive symptoms than the general population and exceed the mean for all patients treated in our pain clinic.

Conclusions

In neuropathies, treatment of the neuropathic pain has a modulating effect on mental disorders. As CRPS patients are frequently affected by depressions, and owing to the connection between depression and suicidal tendencies, patients should be seen by a consultation-liaison psychiatrist, and nonpsychiatrists should pay special attention to this patient group.

[Complex regional pain syndrome]

Complex regional pain syndrome (CRPS) is not a very common yet typical complication of extremity trauma in the daily practice of a trauma surgeon. The pathophysiology of this puzzling disease is still not completely understood and its impact on the patient cannot be overestimated. However, advantages have been made in diagnostics and therapy. While a multitude of different diagnostic systems has led to confusion in the past, we now have an internationally accepted, validated and easy to reproduce diagnostic algorithm in the form of the Budapest criteria. The adequate therapy is still a field for debate, but there is now a broad choice of conservative and interventional treatments for the out- and inpatient setting.

Mental load during cognitive performance in complex regional pain syndrome I

BACKGROUND

Complex regional pain syndrome (CRPS) is associated with deficits in limb recognition. The purpose of our study was to determine whether mental load during this task affected performance, sympathetic nervous system activity or pain in CRPS patients.

METHODS

We investigated twenty CRPS-I patients with pain in the upper extremity and twenty age- and sex-matched healthy controls. Each participant completed a limb recognition task. To experimentally manipulate mental load, the presentation time for each picture varied from 2 s (greatest mental load), 4, 6 to 10 s (least mental load). Before and after each run, pain intensity was assessed. Skin conductance was recorded continuously.

RESULTS

Patients with CRPS did not differ from controls in terms of limb recognition and skin conductance reactivity. However, patients with CRPS reported an increase in pain during the task, particularly during high mental load and during the latter stages of the task. Interestingly, state anxiety and depressive symptoms were also associated with increases in pain intensity during high mental load.

CONCLUSIONS

These findings indicate that high mental load intensifies pain in CRPS. The increase of pain in association with anxiety and depression indicates a detrimental effect of negative affective states in situations of high stress and mental load in CRPS.

SIGNIFICANCE

The effects of mental load need to be considered when patients with CRPS-I are investigated for diagnostic or therapeutic reasons.

Complex Regional Pain Syndrome, Current Concepts and Treatment Options

PURPOSE OF REVIEW

Complex regional pain syndrome (CRPS) refers to a chronic pain condition that is characterized by progressively worsening spontaneous regional pain without dermatomal distribution. The symptomatology includes pain out of proportion in time and severity to the inciting event. The purpose of this review is to present the most current information concerning epidemiology, diagnosis, pathophysiology, and therapy for CRPS.

RECENT FINDINGS

In recent years, discovery of pathophysiologic mechanisms of CRPS has led to significant strides in the understanding of the disease process. Continued elucidation of the underlying pathophysiological mechanisms will allow for the development of more targeted and effective evidence-based therapy protocols. Further large clinical trials are needed to investigate mechanisms and treatment of the disorder.

Complex regional pain syndrome-up-to-date

Complex regional pain syndrome (CRPS) was described for the first time in the 19th century by Silas Weir Mitchell. After the exclusion of other causes, CRPS is characterised by a typical clinical constellation of pain, sensory, autonomic, motor, or trophic symptoms which can no longer be explained by the initial trauma. These symptoms spread distally and are not limited to innervation territories. If CRPS is not improved in the acute phase and becomes chronic, the visible symptoms change throughout because of the changing pathophysiology; the pain, however, remains. The diagnosis is primarily clinical, although in complex cases further technical examination mainly for exclusion of alternative diagnoses is warranted. In the initial phase, the pathophysiology is dominated by a posttraumatic inflammatory reaction by the activation of the innate and adaptive immune system. In particular, without adequate treatment, central nociceptive sensitization, reorganisation, and implicit learning processes develop, whereas the inflammation moderates. The main symptoms then include movement disorders, alternating skin temperature, sensory loss, hyperalgesia, and body perception disturbances. Psychological factors such as posttraumatic stress or pain-related fear may impact the course and the treatability of CRPS. The treatment should be ideally adjusted to the pathophysiology. Pharmacological treatment maybe particularly effective in acute stages and includes steroids, bisphosphonates, and dimethylsulfoxide cream. Common anti-neuropathic pain drugs can be recommended empirically. Intravenous long-term ketamine administration has shown efficacy in randomised controlled trials, but its repeated application is demanding and has side effects. Important components of the treatment include physio- and occupational therapy including behavioural therapy (eg, graded exposure in vivo and graded motor imaging). If psychosocial comorbidities exist, patients should be appropriately treated and supported. Invasive methods should only be used in specialised centres and in carefully evaluated cases. Considering these fundamentals, CRPS often remains a chronic pain disorder but the devastating cases should become rare.

[Complex pain regional syndrome after distal radius fractures]

Complex regional pain syndrome (CPRS) greatly affects the outcomes of distal radius fractures in terms of functional recovery, time away from work and patient satisfaction. The diagnosis is sometimes difficult to make in the immediate post-injury period. The disproportionate nature of the pain in the absence of differential diagnoses and the presence of a pain-free interval should arouse suspicion. The natural history consists of spontaneous improvement except in some refractory forms. The treatment is multidisciplinary combining a physician specializing in pain, therapist and psychologist coordinated by the surgeon who must not abandon the patient. Treatment aims to improve the patient's comfort and quality of life. Recent treatment approaches aimed at improving cortical reorganization have demonstrated their effectiveness. Surgery has to be considered even in the acute phase to address any causes of pain that can be resolved and address secondary stiffness. Significant progress has to be made in our understanding of the pathogenesis of CPRS to improve treatment and shift this condition to a regional pain syndrome.

Adult Complex Regional Pain Syndrome Type I: A Narrative Review

Complex regional pain syndrome type I (CRPS I) is a multifactorial painful disorder with a complex pathogenesis. Both peripheral and central mechanisms are involved. Acute CRPS I is considered to be an exaggerated inflammatory disorder; however, over time, because of altered function of the sympathetic nervous system and maladaptive neuroplasticity, CRPS I evolves into a neurological disorder. This review thoroughly describes the pathophysiological aspects of CRPS I and summarizes the potential therapeutic options. The mechanisms and targets of the treatment are different in the early and late stages of the disease. This current review builds on a previous review by this author group by deepening the role of the peripheral classic and neuronal inflammatory component in the acute stage of this painful disorder.

LEVEL OF EVIDENCE

Not applicable.

Increased prevalence of posttraumatic stress disorder in CRPS

BACKGROUND

Although specific psychological disorders in complex regional pain syndrome (CRPS) have not been identified, studies suggest that CRPS patients may have increased rates of traumatic life events. Because these events do not always lead to apparent psychological symptoms, we systematically screened CRPS patients for posttraumatic stress disorder (PTSD) to determine if PTSD could be a risk factor for CRPS.

METHODS

Consecutive CRPS patients referred to two university hospital centres (University of Erlangen, UMC Mainz) between December 2011 and April 2013 were prospectively examined using a diagnostic PTSD instrument (Post-traumatic Stress Diagnostic Scale (PDS). We also tested maladaptive coping strategies (brief-COPE inventory) and the PDS severity score as predictors for CRPS. Patients with non-CRPS extremity pain and healthy individuals were used as control groups.

RESULTS

We collected data from 152 patients with CRPS, 55 control patients and 55 age- and sex-matched healthy individuals. Fifty-eight CRPS patients (38%), six non-CRPS pain patients (10%) and two healthy individuals (4%) met diagnostic criteria for PTSD. Initial PTSD symptom onset was prior to CRPS in 50 CRPS patients (86%) and during the course of CRPS in eight patients. Results of a logistic regression revealed that the PTSD severity score was associated with CRPS (p < 0.0001). Maladaptive coping strategies (p < 0.0001) were related to PTSD.

CONCLUSIONS

posttraumatic stress disorder (PTSD) is more frequent in patients with CRPS than it is in the general population.

SIGNIFICANCE

Research has not yet provided support for specific psychological predictors for CRPS.

Management of patients with complex regional pain syndrome type I

Complex regional pain syndrome type I (CRPS-I) includes different conditions characterized by regional pain and sensory, motor, sudomotor, vasomotor, and/or trophic findings, affecting a peripheral limb usually after a noxious event, such as a trauma or surgery. The pathophysiology is still poorly understood. Limited data are available on the incidence of CRPS-I, and the disease is underestimated and under-diagnosed. The disease shows a female preponderance approximately 3:1 with a peak age of incidence around the 5th and 6th decade. The available diagnostic criteria for CRPS-I rely on clinical criteria that are unfortunately focused on the signs and symptoms of the chronic and late disease, while little emphasis is given to the typical imaging (X-rays, bone scintigraphy, MRI) findings of the early phase. Over the last decades, several therapies have been proposed but the few studies available are often too small to be conclusive and rarely evolved to randomized controlled trials (RCTs). On the basis of the results of a few RCTs, only short courses of high bisphosphonate doses appear to provide substantial benefits. The best results are seen in patients in the early phase of the disease, often with the persistent remission or complete healing of the conditions. Since the only accredited mechanism of action of bisphosphonates is the suppression of osteoclastic bone resorption, it is likely the initial dramatic bone loss plays a role in the maintenance and evolution of CRPS-I. Short courses of high doses of bisphosphonates should be considered the treatment of choice for patients with CRPS-I.

Can we reduce the incidence of complex regional pain syndrome type I in distal radius fractures? The Liverpool experience

Introduction

Complex regional pain syndrome is a multifaceted condition, which is relatively common after distal radius fracture.

Method

A series of audits and service evaluations were conducted from 2004 to 2013 to investigate the incidence of complex regional pain syndrome type I and any correlation to tight, restrictive, over-flexed casts. Simple subsequent clinical and patient management changes were implemented and impact re-evaluated.

Results

These audits have contributed to organisational learning and a subsequent reduction in the incidence of complex regional pain syndrome type I in non-operatively managed distal radius fracture from 25%, in keeping with expected incidence in the relevant literature, to a rare event (<1%).

Conclusion

The authors suggest that careful attention to the prevention of complex regional pain syndrome through staff and patient awareness, vigilance for warning signs and minor modifications to the traditional management of distal radius fractures can significantly reduce the incidence of complex regional pain syndrome type I after distal radius fracture.

Complex regional pain syndrome type I: a comprehensive review

BACKGROUND

Complex regional pain syndrome type I (CRPS I), formerly known as reflex sympathetic dystrophy (RSD), is a chronic painful disorder that usually develops after a minor injury to a limb. This topical review gives a synopsis of CRPS I and discusses the current concepts of our understanding of CRPS I in adults, the diagnosis, and treatment options based on the limited evidence found in medical literature. CRPS I is a multifactorial disorder. Possible pathophysiological mechanisms of CRPS I are classic and neurogenic inflammation, and maladaptive neuroplasticity. At the level of the central nervous system, it has been suggested that an increased input from peripheral nociceptors alters the central processing mechanisms.

METHODS

A literature search was conducted using, as electronic bibliographic database, Medline from 1980 until 2014.

RESULTS

An early diagnosis and multidisciplinary treatment are necessary to prevent permanent disability.

CONCLUSIONS

The pharmacological treatment of CRPS I is empirical and insufficiently effective. Further research is needed regarding the therapeutic modalities discussed in the guidelines. Physical therapy is widely recommended as a first-line treatment. The efficacy of local anesthetic sympathetic blockade as treatment for CRPS I is questionable.

Psychological distress and stressful life events in pediatric complex regional pain syndrome

BACKGROUND

There is little knowledge regarding the association between psychological factors and complex regional pain syndrome (CRPS) in children. Specifically, it is not known which factors precipitate CRPS and which result from the ongoing painful disease.

OBJECTIVES

To examine symptoms of depression and anxiety as well as the experience of stressful life events in children with CRPS compared with children with chronic primary headaches and functional abdominal pain.

METHODS

A retrospective chart study examined children with CRPS (n=37) who received intensive inpatient pain treatment between 2004 and 2010. They were compared with two control groups (chronic primary headaches and functional abdominal pain; each n=37), who also received intensive inpatient pain treatment. Control groups were matched with the CRPS group with regard to admission date, age and sex. Groups were compared on symptoms of depression and anxiety as well as stressful life events.

RESULTS

Children with CRPS reported lower anxiety and depression scores compared with children with abdominal pain. A higher number of stressful life events before and after the onset of the pain condition was observed for children with CRPS.

CONCLUSIONS

Children with CRPS are not particularly prone to symptoms of anxiety or depression. Importantly, children with CRPS experienced more stressful life events than children with chronic headaches or abdominal pain. Prospective long-term studies are needed to further explore the potential role of stressful life events in the etiology of CRPS.

Complex regional pain syndrome: From diagnosis to rehabilitation

Complex regional pain syndrome (CRPS) is a debilitating pathology characterised by intense chronic pain associated with vasomotor, sensory and motor dysfunction of the affected limb. Although the pathophysiology of CRPS is not fully understood, it is recognised that inflammatory processes and autonomic dysfunction are involved. These processes are associated with peripheral and central sensitisation as well as changes in brain structure and function, and are reflected in the clinical presentation of CRPS. CRPS management requires an interdisciplinary team and requires the therapeutic approach to be individualised. With regard to pharmacological treatment, bisphosphonates, corticosteroids, ketamine and anticonvulsants have been demonstrated to be effective for CRPS management. Psychotherapy, including cognitive-behavioural therapy, has produced promising results but more studies are needed to confirm its efficacy. Among rehabilitation interventions, there is evidence of the efficacy of physiotherapy and occupational therapy in diminishing CRPS symptoms and achieving a higher level of functioning. In this regard, the rehabilitation modality that seems the most promising according to the actual literature is graded motor imagery, which can help to reverse the maladaptive neuroplasticity occurring in CRPS.