Pediatric Complex Regional Pain Syndrome and Occupational Therapy Intervention: A Scoping Review

Complex regional pain syndrome (CRPS) is an increasingly recognized pain condition in the pediatric population. Occupational therapy (OT) is a crucial component of a multidisciplinary approach to treating pediatric CRPS. Yet, there is limited evidence detailing these OT interventions. This review aimed to explore the existing literature on OT interventions and delivery methods for pediatric CRPS. We performed a scoping review of peer-reviewed articles that included pediatric participants with CRPS with no limitation on publication date. Most of the 11 included studies described OT interventions that addressed pain, functional disability, motor and sensory function, social participation, and psychological well-being. Interventions included sensory reeducation programs, exercises, functional use of affected extremities, psychoeducation, and client and family education. To facilitate engagement in meaningful occupations, OT practitioners treating pediatric CRPS should provide evidence-based interventions and age-appropriate client education and include caregivers in the care plan.

Anxiety, Disability, and Pain Predict Outcomes of Complex Regional Pain Syndrome: An 8-year Follow-up of a Prospective Cohort

Factors contributing to the varied outcomes of complex regional pain syndrome (CRPS) are not well known. This study aimed to determine whether baseline psychological factors, pain, and disability influence long-term CRPS outcomes. We conducted an 8-year follow-up from a previous prospective study of CRPS outcomes. Sixty-six people diagnosed with acute CRPS were previously assessed at baseline, 6 months, and 12 months and in the current study, 45 were followed up after 8 years. At each timepoint, we measured signs and symptoms of CRPS, pain, disability, and psychological factors. Mixed-model repeated measures were used to identify baseline predictors of CRPS severity, pain, and disability at 8 years. Predictors of greater CRPS severity at 8 years were female sex, greater baseline disability, and greater baseline pain. Predictors of greater pain at 8 years were greater baseline anxiety and disability. The only predictor of greater disability at 8 years was greater baseline pain. Findings suggest CRPS is best understood from a biopsychosocial perspective, and baseline anxiety, pain, and disability may influence the trajectory of CRPS outcomes as far as 8 years later. These variables could be used to identify those at risk of poor outcomes or form targets for early interventions. PERSPECTIVE: This paper presents the findings of the first study to prospectively investigate predictors of CRPS outcomes over 8 years. Baseline anxiety, pain, and disability predicted greater CRPS severity, pain, and disability over 8 years. These factors could identify those at risk of poor outcomes or form targets for early interventions.

Long-term biopsychosocial issues and health-related quality of life in young adolescents and adults treated for childhood Complex Regional Pain Syndrome, type 1

OBJECTIVES

Treatment for childhood Complex Regional Pain Syndrome (CRPS) is associated with long-term recovery. The present study aimed to investigate the long-term biopsychosocial status and quality of life in young adolescents and adults after the treatment of childhood CRPS.

METHODS

A 4 year follow-up of individuals with childhood-CRPS, type 1 (n=22; age:12 years (years) [median] at treatment and 17 years at follow-up) was completed. Biopsychosocial status and quality of life were assessed with structured interviews, using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), the Strengths and Difficulties Questionnaire (SDQ), the Pediatric Pain Coping Inventory (PPCI), and the Pediatric Quality of Life Inventory (PedsQL). Comparisons were made with normative samples of age-matched controls.

RESULTS

CRPS at follow-up was still present in seven out of 22, and non-CRPS pain symptoms were found in 12 out of 22 individuals. Signs of mental health pain-related problems, including phobias and obsessive-compulsive disorder, were observed in ten out of 19 individuals. Mental well-being, social functioning, and quality of life (SDQ and PedsQL) were independent of pain status (p>0.05). Adaptive pain coping strategies were utilized regardless of pain status (PPCI). Social functioning (p<0.01) and the quality of life (p=0.01) were attenuated and statistically significantly poorer than healthy age-matched young adults but better than for fibromyalgia subjects.

CONCLUSIONS

A subset of individuals treated for childhood-CRPS, type 1 experiences long-term consequences of persistent pain, a decrease in quality of life indicators, and demonstrates significant psychosocial issues. Childhood-CRPS is suggested to be associated with long-term psychosocial consequences and poorer quality of life than found in age-related healthy peers. Subjects treated for childhood CRPS may need a longer clinical follow-up attempting to preclude relapse of CRPS and non-CRPS pain.

Sensory Function and Psychological Factors in Children With Complex Regional Pain Syndrome Type 1

OBJECTIVE

To assess thermal-sensory thresholds and psychosocial factors in children with Complex Regional Pain Syndrome Type 1 (CRPS-I) compared to healthy children.

METHODS

We conducted quantitative sensory testing on 34 children with CRPS-I and 56 pain-free children. Warm, cool, heat, and cold stimuli were applied to the forearm. Children with CRPS-I had the protocol administered to the pain site and the contralateral-pain site. Participants completed the self-report Behavior Assessment System for Children.

RESULTS

Longer pain durations (>5.1 months) were associated with decreased sensitivity to cold pain on the pain site (P = .04). Higher pain-intensity ratings were associated with elevated anxiety scores (P = .03). Anxiety and social stress were associated with warmth sensitivity (both P < .05) on the contralateral-pain site.

CONCLUSIONS

Pain duration is an important factor in assessing pediatric CRPS-I. Hyposensitivity in the affected limb may emerge due to degeneration of nociceptive nerves. Anxiety may contribute to thermal-sensory perception in childhood CRPS-I.

Symptom reduction and improved function in chronic CRPS type 1 after 12-week integrated, interdisciplinary therapy

Background and aims Complex Regional Pain Syndrome (CRPS) often recovers spontaneously within the first year, but when it becomes chronic, available rehabilitative therapies (pharmacological management, physiotherapy, and psychological intervention) have limited effectiveness. This study examined the effect of a 12-week intensive outpatient rehabilitation on pain relief and function in chronic CRPS patients. Rehabilitation program included memantine and morphine treatment (added to patient's prior pain medication) and concurrent psychological and physiotherapeutic intervention. Primary outcome measure was a change in CRPS symptom count and secondary outcomes were motor performance, psychological factors, pain intensity, and quality of life. Methods Ten patients with chronic upper limb CRPS I (median 2.9 years, range 8 months to 12 years) were recruited to the study and were assessed before and after the intervention. Hand motor function of the patients was evaluated by an independent physiotherapist. There were standardized questionnaires for depression, pain anxiety, pain acceptance, quality of life, and CRPS symptom count. In addition, psychological factors were evaluated by a semi-structured interview. Severity of experienced pain was rated at movement and at rest. In addition, a video experiment of a hand action observation was conducted pre- and post-intervention to study possible change in neuronal maladaptation. Intervention consisted of pharmacological, psychological and physiotherapeutic treatment. First, 10 mg daily morphine was started and increased gradually to 30 mg daily, if tolerated. After 30 mg/day or tolerated dose of morphine was achieved, 5 mg daily memantine was started and increased gradually to 40 mg, if tolerated. Psychological intervention consisted of weekly group sessions, using cognitive and behavioral methods (relaxation, behavioral activation, and exposure) and acceptance and commitment therapy (ACT) and daily home practice. Physiotherapeutic intervention consisted of graded motor imagery and physiotherapy exercises with weekly group sessions and/or individual guidance by the physiotherapist, and individual exercise of the affected upper limb. Results Multimodal intensive intervention resulted in significant decrease in CRPS symptom count. The effect was strongest in motor and trophic symptoms (19% decrease after intervention) and in sensory symptoms (18% decrease). Additionally, improvement was seen in some, but not all, secondary outcomes (movement pain, motor symptoms, change in perceptions during video experiment of hand actions, and summary index with motor functioning, pain, and psychological factors). There were no dropouts. Conclusions Intensive 12-week multimodal intervention reduced some CRPS symptoms but was not sufficient to alter patients' rest pain, distress, or quality of life. Implications These results support the efficacy of an interdisciplinary rehabilitation program for pain and function in chronic CRPS patients. After intervention, some CRPS symptoms reduced and function improved, but distress and quality of life were unchanged. This may be due to the relatively short duration of this program; to delayed effects; to particular cognitive problems of CPRS patients; and/or to low distress levels at baseline that make statistically significant reduction less likely.

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.

Complex Regional Pain Syndrome After Distal Radius Fracture Is Uncommon and Is Often Associated With Fibromyalgia

BACKGROUND

Complex regional pain syndrome (CRPS) is frequently diagnosed in patients recovering from surgery or injury. The symptoms and signs included in consensus diagnostic criteria for CRPS are expected after injury. Categorizing symptoms and signs that occur on a continuum as disproportionate or not is subjective and prone to bias. Psychiatrists and psychologists do not diagnose CRPS and instead measure and treat anxiety and catastrophic thinking on its continuum. Given the expected variation in subjective diagnoses such as CRPS, this study addresses factors associated with use of this diagnosis and how it influences care.

QUESTIONS/PURPOSES

(1) Among patients recovering from fracture of the distal radius, what factors are associated with the diagnosis of CRPS? (2) Are patients diagnosed with CRPS after distal radius fractures, as opposed to those without CRPS, more likely to have a bone scan, stellate ganglion block, therapy, or subsequent surgery?

METHODS

Using the Truven database, we identified 59,765 patients treated for a distal radius fracture from 2012 to 2014, of whom 114 (0.19%) were diagnosed with CRPS. The Truven Health MarketScan database is an administrative claims data set of commercially insured patients and this analysis only included patients with complete enrollment from 2012 through 2014. Bivariate analyses sought differences between patients diagnosed with and patients not diagnosed with CRPS. All factors with p < 0.05 were included in a multivariable logistic regression model.

RESULTS

The covariates older age (odds ratio [OR], 1.029; 95% confidence interval [CI], 1.011-1.048; p = 0.002), gender (women at greater risk, OR, 3.86; CI, 1.99-7.49; p < 0.001), concomitant fracture of the distal ulna (OR, 1.54; CI, 1.05-2.23; p = 0.029), open fracture (OR, 0.414; CI, 0.192-0.895; p = 0.025), and comorbid fibromyalgia (OR, 16.0; CI, 4.92-51.8; p < 0.001) were independently associated with a diagnosis of CRPS among patients recovering from a fracture of the distal radius. Patients diagnosed with CRPS are more likely than other patients with a distal radius fracture to have had a bone scan (OR, 66.0; CI, 8.19-532; p < 0.001), physical or occupational therapy (OR, 3.89; CI, 2.68-5.67; p < 0.001), and subsequent wrist surgery (OR, 2.52; CI, 1.65-3.84; p < 0.001). No one had a stellate ganglion injection.

CONCLUSIONS

We found that a coded diagnosis of CPRS is uncommonly applied to patients on the higher range of pain, stiffness, and limitations after fracture of the distal radius-most commonly in women and in association with another nonspecific, objectively unverifiable diagnosis (fibromyalgia)-and that this label may lead to more testing and invasive treatment. Future research should address the utility and value of diagnoses that create subjective categories for aspects of human illness that occur on a continuum.

LEVEL OF EVIDENCE

Level III, prognostic study.

Different patterns in mental rotation of facial expressions in complex regional pain syndrome patients

Although facial pain expressions are considered to be the most visible pain behaviors, it is known that the association between pain intensity and facial pain expression is weak for chronic pain. The authors hypothesized that the facial pain expressiveness was altered in chronic pain and investigated it with a mental rotation task using various facial expression, which seems to be associated with actual facial movements. As a task stimulus, 4 types of facial expression stimuli consisted of upper (tightening of eye and furrowed brows) and lower (raising upper lip) pain-specific facial expressions, and upper (eyeball deviation) and lower (tongue protrusion) facial movements not using facial muscles were used. Participants were asked to judge whether a stimulus presented at various rotation angles was left- or right-sided. The authors tested 40 patients with complex regional pain syndrome (CRPS) (12 women, age range 21-60) and 35 healthy controls (15 women, age range 26-64). In an analysis of reaction time (RT) using a linear mixed model, patients were slower to react to all types of stimuli (P = .001) and a significant interaction between group (patient or control) and type of facial expression was observed (P = .01). In the post hoc analysis only patients showed longer RTs to raising upper lip than other types of facial expressions. This reflects a deficit in mental rotation tasks especially for lower facial region pain expressions in CRPS, which may be related to the psychosocial aspects of pain. However, comprehensive intra- and interpersonal influences should be further investigated.

[Chronic pain : Perception, reward and neural processing]

Many chronic pain syndromes are characterized by enhanced perception of painful stimuli as well as alterations in cortical processing in sensory and motor regions. In this review article the alterations in muscle pain and neuropathic pain are described. Alterations in patients with fibromyalgia and chronic back pain are described as examples for musculoskeletal pain and also in patients with phantom limb pain after amputation and complex regional pain syndrome as examples for neuropathic pain. In addition to altered pain perception, cumulative evidence on alterations in the processing of reward and the underlying mechanisms in chronic pain has been described. A description is given of what is known on how pain and reward interact and affect each other. The relevance of such interactions for chronic pain is discussed. The implications of these findings for therapeutic approaches are delineated with respect to sensorimotor training and behavioral therapy, focusing on the effectiveness of these approaches, mechanisms and future developments. In particular, we discuss operant behavioral therapy in patients with chronic back pain and fibromyalgia as well as prosthesis training in patients with phantom limb pain and discrimination, mirror and imaginary training in patients with phantom limb pain and complex regional pain syndrome. With respect to the processing of reward, the focus of the discussion is on the role of reward and associated learning in pain therapy.

EFFECTS OF MEMANTINE ON PAIN IN PATIENTS WITH COMPLEX REGIONAL PAIN SYNDROME--A RETROSPECTIVE STUDY

INTRODUCTION

Memantine was discovered in 1968 and is used as a treatment for Alzheimer's disease. We evaluated the use of memantine to treat complex regional pain syndrome in this retrospective study.

PATIENTS AND METHODS

56 patients with CRPS, who were treated with trial of memantine for at least two months with 40mg QHS from 2007 until 2009.

RESULTS

34 females and 22 male patients. Age-46.0 +/- 9.7 years. Number of years with CRPS-9.24 ± 5.7 years. Mean age-46.0 +/- 9.7 years. Memantine was started at 5 or 10 mg QHS, before being increased by 5 or 10mg every 4-7 days, as tolerated, to a maximumdose of 40 mg - 60 mg, as tolerated. In all, 13 patients showed complete remission from CRPS with VAS 0 and the disappearance of allodynea for at least nine months after the use of memantine. In addition, 18 patients showed partial improvement of VAS and allodynea. Eight patients showed no improvement even after continuous use of memantine at a dose of 40 mg QHS for two months. Seven patients could not take more than 5 mg of memantine per day and had to stop it due to side effects. In terms of subjective improvement in short-term memory, nine patients showed much improvement, 14 patients showed some improvement, three patients showed no changes and one patient did not answer the questionnaire. Regarding subjective feelings of a having better quality of life, 17 patient answered yes, three did not feel any changes, six could not give an answer and two did not fill out the questionnaire.

CONCLUSIONS

Memantine is a promising option for the treatment of CRPS. A randomised controlled study is needed to evaluate its efficacy.

The therapeutic approach to complex regional pain syndrome: light and shade

Complex regional pain syndrome (CRPS) is a highly painful, limb-confined condition that usually arises after a trauma although its causes remain unknown. It is associated with a particularly poor quality of life, and considerable healthcare and societal costs. Its distinct combination of abnormalities includes limb-confined inflammation and tissue hypoxia, sympathetic dysregulation, small fibre damage, serum autoantibodies, central sensitisation and cortical reorganisation, which place it at the crossroads of disciplines including rheumatology, pain medicine and neurology. The significant scientific and clinical advances made over the past 10 years promise an improved understanding of the causes of CRPS, and for more effective treatments. This review summarises the currently available treatments. The therapeutic approach is multidisciplinary, and involves educating patients about the condition, sustaining or restoring limb function, reducing pain, and providing psychological support. This paper describes the systemic drug treatments, grouped on the basis of their real or presumed antinociceptive mechanisms and reported actions without making any formal distinction between CRPS types I and II.

Outcomes of a Simple Treatment for Complex Regional Pain Syndrome Type I in Children

BACKGROUND

Chronic Regional Pain Syndrome type I (CRPSI) in children is a disorder of unknown etiology. No standard diagnostic criteria or treatment exists. Published treatment protocols are often time and resource intensive. Nonetheless, CRPSI is not rare and can be disabling. This reports the results of a simple and inexpensive treatment protocol involving no medicines, nerve blockades, physical therapy resources or referrals to pain specialists. The patient is instructed in a self-administered massage and mobilization program. The diagnosis required allodynia (pain on light touch of the skin) and signs or the history of signs of autonomic dysfunction.

METHODS

A chart review of patient coded for "reflex sympathetic dystrophy" or 'autonomic dysfunction" was performed yielding a cohort of eighty-three patients treated by a common protocol. Most patients were identified in the last 15 years. Most patients with this CRPSI were doubtless coded simply as "foot pain" or "knee pain", etc and were not identified in this search. Charts were reviewed for patient demographics and outcomes. A subset of patients filled out the Pediatric Outcomes Data Collection Instrument (PODCI) giving a validated pre-treatment disability measure.

RESULTS

The cohort characteristics were similar to prior reports with respect to age, gender, location, and history of trauma. Of the 26 patients who completed the PODCI before treatment the Pain/Comfort Core Scale score mean was 20.81(0-63). The Global Functioning Scale score mean was 52.11(27-83.5). Eighty-nine percent of 51 patients who attended clinic until their outcome was definite had no or minimal residual pain. Treatment averaged 2.2 visits per patient, typically over a six-week period.

CONCLUSIONS

A simple, inexpensive protocol can be effective in treating CRPSI in children. The protocol is risk free, inexpensive to families and conservative of physician and physical therapy resources.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Short-term treatment with parecoxib for complex regional pain syndrome: a randomized, placebo-controlled double-blind trial

BACKGROUND

Complex regional pain syndrome (CRPS) is characterized by signs and symptoms of peripheral inflammation, which leads to peripheral neural sensitization associated most frequently (in about 70%) with blunt pressure hyperalgesia. Therefore, we hypothesized that treatment of CRPS patients with a selective COX-2-inhibitor would alleviate the abnormally low pressure pain threshold (PPT) and reduce pain intensity and edema.

METHODS

Twenty patients with CRPS type I (n = 16) and II of the upper limb and abnormally low PPT were double-blind randomised into 2 groups of 10 patients each to receive a 2-day intravenous treatment of either 80 mg parecoxib per day (group I) or placebo (NaCl 0.9%, group II). Standardized quantitative sensory testing (QST) using the DFNS protocol was performed before and after treatment. Pain intensity (NRS 0 - 10); circumferences of the fingers II, IV, and V (mm); PPT (kPa, thenar/hypothenar); and adverse events were recorded daily.

STATISTICS

Wilcoxon-test, Mann-Whitney-U-test, Friedman-test, Fisher-test, significance level: P < 0.05.

STUDY DESIGN

Proof of concept trial performed in randomized, placebo-controlled, double blind style .

SETTING

Pain Management Center in Germany.

RESULTS

There were no group differences in PTT or other QST parameters. After treatment, PPT decreased insignificantly in group I (median [range]; before: 224.0 [121.0 - 52937] kPa, afterwards: 186.4 [101.4 - 526.5] kPa) and increased insignificantly in group II (before: 207.6 [170.0 - 320.5] kPa; afterwards: 235.4 [163.5 - 349.9] kPa). Pain scores and finger circumferences remained unchanged in both groups.

LIMITATIONS

Due to difficulty in recruitment the trial was closed after inclusion of 20 patients.

CONCLUSION

In the present proof-of-concept trial, short-term treatment with the selective COX-2-inhibitor parecoxib influenced neither PPT nor edema or pain. COX-2 might be less important than previously assumed. However, the results are limited due to the small number of patients, short-term treatment, and focus on the PPT, which could have led to false negative results of the present study and covered the expected therapeutic effect.

Prednisolone in complex regional pain syndrome

BACKGROUND

Although there are several studies of systemic corticosteroid therapies in various doses and various durations in complex regional pain syndrome (CRPS), the outcome measurement parameters are limited to the range of motion measurements, edema, and symptoms of CRPS.

OBJECTIVE

To investigate the effects of prednisolone on clinical symptoms, pain, hand grip strength, range of motion, as well as on functional ability and quality of life in patients who developed CRPS after traumatic upper extremity injury.

STUDY DESIGN

Retrospective evaluation.

METHODS

Forty-five patients who used prednisolone for CRPS of the upper extremity were retrospectively studied. Prednisolone was started with a dose of 30 mg and tapered by 5 mg every 3 days until discontinuation after 3 weeks. Clinical symptoms (morning stiffness, cold intolerance, shoulder pain, numbness of fingers, hyperesthesia, abnormal sweating, and cyanosis that is exacerbated by exposure to cold temperature), pain (Visual Analogue Scale-Rest [VAS-R] and VAS-Activity [VAS-A]) were reviewed. The muscle strength with grip strength (GS) (kg), lateral pinch (LP) (pound), tip-to-tip pinch (TP) (pound), and chuck pinch (CP) (pound) measurements; the joint range of motion with using third finger tip-distal crease distance (FT-DC) (cm); functional ability with Quick-Disabilities of the Arm, Shoulder and Hand (Q-DASH) score; and quality of life with Short Form-36 (SF-36) score were evaluated.

RESULTS

Mean age was 43.53 ± 11.43 years. After 3 weeks of therapy, patients showed significant improvements in clinical symptoms compared to the basal assessments (P < 0.05). The comparison of pre- and post-treatment results revealed that VAS-R, VAS-A, GS, LP, TP, CP, FT-DC, Q-DASH scores, and all SF-36 subscores were significantly improved (P < 0.05).

LIMITATIONS

The retrospective design and data collection procedure was limited to the medical records of patients.

CONCLUSION

A short-term oral prednisolone therapy significantly reduced the symptoms and signs of CRPS, and improved the functional abilities and quality of life.

Cognitive correlates of "neglect-like syndrome" in patients with complex regional pain syndrome

Patients with complex regional pain syndrome (CRPS) often show distinct neurocognitive dysfunctions, which were initially termed "neglect-like symptoms." So far, particularly the patients' feelings about the affected extremity, motor, and sensory aspects of the "neglect-like symptoms" have been investigated, possibly pointing to a disturbed body schema. Because patients with classical neurological neglect show diminished awareness regarding the perception of their body, as well as of the space around them, our hypothesis was that CRPS patients exhibit some signs of personal neglect and extrapersonal visuospatial problems over and beyond those seen in patients simply suffering from limb pain. We used quantitative sensory testing and motor assessment aimed at detecting motor and sensory loss, a standardized questionnaire calculating a neglect score, and applied a detailed neuropsychological test battery assessing different parietal lobe functions, including visual neglect. We examined 20 CRPS patients and 2 matched control groups, one consisting of healthy subjects and the other one of patients with limb pain other than CRPS. Results show significant higher neglect scores for CRPS patients and the pain control group, but interestingly, CRPS patients and pain patients were indistinguishable. The results of the neuropsychological test battery did not demonstrate systematic variances, which would be indicative of a classical neurological neglect in CRPS patients, even though there were 3 CRPS patients who differed ≥ 2 SD from the mean of our healthy control group, with poorer results in ≥ 3 different tests. We assume that the "neglect-like syndrome" in most CRPS patients is different from typical neglect.

[Chronic right-sided pain-associated nondermatomal somatosensory deficit following an accident]

We present the case of a 48-year old man who, eight years after an industrial accident, presents with chronic right-sided nondermatomal pain and hypaesthesia to heat and touch. During symmetric peripheral touch functional magnetic resonance imaging revealed hypometabolism in the left thalamus, somatosensory cortex, and anterior cingulate cortex. Pain-associated nondermatomal somatosensory deficits (NDSDs) localizing to one side of the body are a frequent clinical entity, which are often triggered by an accident. The tendency of NDSDs to extend to adjunct ipsilateral body parts and to become chronic points to maladaptive adjustment of pain-processing areas in the central nervous system. Psychological stress prior to or around the triggering event seems an important risk factor for NDSDs.

Complex regional pain syndrome: the role of the psychiatrist as an expert witness

Complex regional pain syndrome (CRPS) is a regional pain syndrome of unclear pathophysiology, typically affecting the hand or foot. CRPS can be subject to personal injury litigation and may be the cause of substantial future loss of earnings claims. In clinical practice, a variety of medical experts can be involved in the diagnosis and management of CRPS and this can lead to confusion about the most appropriate expert for lawyers to instruct. This paper defines the role of psychiatrists as experts to the court in CRPS and reviews the associated psychiatric literature. Psychiatrists do not have expertise in the clinical diagnosis of CRPS, but they are able to assess the presence of co-morbid psychiatric conditions. They can assist the court as experts in the underlying neuro-physiological and psychological processes which may explain some of the important features of CRPS and an individual's psychological vulnerability to CRPS. Their expertise in psychological and psycho-pharmacological interventions should be considered for any multidisciplinary treatment programme for CRPS along with the likely contribution of these interventions to the overall prognosis.

[Pediatric complex regional pain syndrome affecting an upper limb: 7 cases and a brief review of the literature]

OBJECTIVES

To review the clinical, psychiatric, and social characteristics of complex regional pain syndrome in children and adolescents treated in the last 4 years at our pediatric pain clinic.

MATERIAL AND METHODS

We analyzed the specialty of the initial treating physician, age, sex, initial diagnosis, pain intensity, degree of disability, fear of movement, clinical stage, history of trauma, time between onset and diagnosis, psychiatric illness, family support and behavior, chronic pain in near relatives, school grades and attendance, treatment given at the pediatric pain clinic, recurrences, and course of disease.

RESULTS

The cases of 7 patients (4 female, 3 male) between the ages of 8 and 15 years were analyzed. Four had been referred by the child psychiatry department. The initial diagnosis was erroneous in all but 1 case. Pain intensity and associated disability were severe in 5 patients and 4 expressed intense fear of moving the limb. Five patients had initial stage I disease, 5 had a history of trauma, and 5 had been previously treated by immobilization of the limb and prescription of nonsteroidal anti-inflammatory drugs. The time between onset and diagnosis ranged from 2 to 18 months (mean [SD], 6.4 [3.5] months). In most cases psychiatric disease and concomitant social disability were present. Treatment prescribed at the pediatric pain clinic consisted of a combination of oral medication, psychologic and psychiatric counseling, and intensive physiotherapy for all but 2 children, who required regional nerve blocks.

CONCLUSION

The clinical course was satisfactory for all but 1 patient, who developed severe disability. Complex regional pain syndrome affecting an upper limb is uncommon in children but not rare.

[Explaining symptoms: body-object and body-subject]

BACKGROUND

Medically unexplained somatic symptoms present a real challenge to modem medicine. They occur frequently and are often chronic.

AIM

To discuss the physician's approach to these symptoms.

METHOD

We focus on the views of the human body put forward by the French philosopher Merleau-Ponty. His view is illustrated with the help of a case study concerning a patient suffering from borderline personality disorder and complex regional pain syndrome.

RESULTS

Merleau-Ponty draws a distinction between body-subject and body-object. By body-object he means the body as determined and predicted by medical science. By body-subject he means the body as we experience it, even before we are aware of it. It is our pre-reflexive body that gives meaning to the world around us.

CONCLUSION

We argue that the physician should regard the body not only as an object, but also as a subject, thereby giving renewed attention to the significance of symptoms as an expression of inner experience. In this way symptoms that cannot be explained on a purely physico-chemical level will become more meaningful.

Psychoneuroendocrine stress response may impair neutrophil function in complex regional pain syndrome

In order to elucidate the interaction between pain, stress and innate immunity in complex regional pain syndrome (CRPS), we assessed pain and stress levels in CRPS patients and compared ex vivo functions of neutrophils between patients with CRPS and healthy volunteers. As compared with healthy volunteers, the following major alterations in CRPS patients were found: (I) elevated stress score (PTSS-10) and stress hormone concentrations, (II) decreased expression of the CD62L and CD11b/CD18 on neutrophils, (III) impaired ability of autologous plasma to enhance the capability of neutrophils to phagocytose zymosan particles, and (IV) a negative correlation between PTSS-10 values and autologous plasma enhanced phagocytosis. In vitro incubation of neutrophils with catecholamines decreased phagocytosis of zymosan. In conclusion, CRPS patients exhibit signs of impaired innate immunity which might reflect the immunological consequence of an immunosuppressive neuroendocrine stress response.

Regional pain syndrome: clinical characteristics, mechanisms and management

Regional soft-tissue complaints are commonplace, and they usually relate to a disease process, such as strain, inflammation or degeneration of a muscle, tendon or related muscle-tendon unit. The clinical features and investigations of the causative processes of these complaints are characteristic, and outcomes to treatments are usually predictable and satisfactory. Regional pain syndromes are different: these syndromes present with regional pain and tenderness, and other sensory symptoms unaccounted for by a simple musculoskeletal mechanistic explanation. Approved classification criteria for regional pain syndromes are lacking, and these syndromes are poorly understood and frequently misdiagnosed. Regional pain syndromes often occur after injury and overlap extensively with other musculoskeletal pain syndromes, in terms of clinical signs and symptoms. The clinician and patient are often confused about the nature of the problem and routine treatments directed to putative tissue damage will fail. Review of the epidemiology of regional pain syndromes combined with knowledge of other similar pain syndromes has enabled an evolving understanding of the condition. The musculoskeletal and central nervous systems both contribute to regional pain syndromes, through spine-related pain mechanisms and central sensitization, respectively. The patient's emotional state, particularly the effect on pain modulation, links these two systems.

The motor system shows adaptive changes in complex regional pain syndrome

The complex regional pain syndrome (CRPS) is a disabling neuropathic pain condition that may develop following injuries of the extremities. In the present study we sought to characterize motor dysfunction in CRPS patients using kinematic analysis and functional imaging investigations on the cerebral representation of finger movements. Firstly, 10 patients and 12 healthy control subjects were investigated in a kinematic analysis assessing possible changes of movement patterns during target reaching and grasping. Compared to controls, CRPS patients particularly showed a significant prolongation of the target phase in this paradigm. The pattern of motor impairment was consistent with a disturbed integration of visual and proprioceptive inputs in the posterior parietal cortex. Secondly, we used functional MRI (fMRI) and investigated cortical activations during tapping movements of the CRPS-affected hand in 12 patients compared to healthy controls (n = 12). During finger tapping of the affected extremity, CRPS patients showed a significant reorganization of central motor circuits, with an increased activation of primary motor and supplementary motor cortices (SMA). Furthermore, the ipsilateral motor cortex showed a markedly increased activation. When the individual amount of motor impairment was introduced as regressor in the fMRI analysis, we were able to demonstrate that activations of the posterior parietal cortices (i.e. areas within the intraparietal sulcus), SMA and primary motor cortex were correlated with the extent of motor dysfunction. In summary, the results of this study suggest that substantial adaptive changes within the central nervous system may contribute to motor symptoms in CRPS.

[The complex regional pain syndrome (CRPS) as differentiation from psychogenic disturbances]

In the course of recent years, after the conception of dystrophic disturbances of the extremities had been reassessed, the CRPS has been making increasing demands on medical treatment and assessment in all insurance classes. There is common agreement that the syndrome can also be triggered by minor trauma. A decisive factor for the expert opinion is first of all the presentation of definite proof that there is actually a dystrophic disturbance present on the affected extremities. The patients concerned frequently suffer from a co-morbidity with accompanying psychological disturbances. For a lot of patients, primary organic effects caused by the injury can be excluded, whereas psychogenically determined symptoms can be found. This leads to significant consequences for the medical assessment under the insurance aspect in the individual case. The differential diagnosis may turn out to be difficult and in individual cases will require the use of the entire available technical diagnostics equipment and the involvement of psychological expert opinions.

Abnormal reactivity of the primary somatosensory cortex during the experience of pain in complex regional pain syndrome: a magnetoencephalograhic case study

A 49-year-old male worker developed persistent pain in his left wrist after work strain injuries. Clinical symptoms met with criteria for Complex Regional Pain Syndrome (CRPS) type I. In the present study, the effect of the experience of pain on the somatotopy of the primary cortical hand representation was investigated. Somatosensory evoked magnetic fields (SEF) elicited by non-painful tactile stimulation at the index finger of the affected and the unaffected hand were recorded when experiencing pain elicited by a moderate physical load condition (holding a 1.6 kg object in the hand). It was shown that MEG and subjective responses to innocuous tactile stimuli were reduced when simultaneous nociceptive stimulation was applied. These findings suggest a gating effect in the central nervous system elicited by concurrent simultaneous information from two different somatosensory modalities (pain and tactile). The results revealed the existence of nociceptive-induced plastic changes in the central nervous system associated with CRPS type I.

Psychological and behavioral aspects of complex regional pain syndrome management

Psychological and behavioral factors can exacerbate the pain and dysfunction associated with complex regional pain syndrome (CRPS) and could help maintain the condition in some patients. Effective management of CRPS requires that these psychosocial and behavioral aspects be addressed as part of an integrated multidisciplinary treatment approach. Well-controlled studies to guide the development of a psychological approach to CRPS management are not currently available. A sequenced protocol for psychological care in CRPS is therefore proposed based on available data and clinical experience. Regardless of the duration of the condition, all CRPS patients and their families should receive education about the negative effects of disuse, the pathophysiology of the syndrome, and possible interactions with psychological/behavioral factors. Patients with acute CRPS (<6-8 weeks) may not need additional psychological care. All patients with chronic CRPS should receive a thorough psychological evaluation, followed by cognitive-behavioral pain management treatment, including relaxation training with biofeedback. Patients making insufficient overall treatment progress or in whom comorbid psychiatric disorders/major ongoing life stressors are identified should additionally receive general cognitive-behavioral therapy to address these issues. The psychological component of treatment can work synergistically with medical and physical/occupational therapies to improve function and increase patients' ability to manage the condition successfully.

Teachers' perceptions of and responses to adolescents with chronic pain syndromes

OBJECTIVE

To examine factors that influence teachers' perceptions of and responses to chronic pain in students.

METHODS

Two-hundred and sixty classroom teachers responded to a vignette describing a student with limb pain. The 2 x 2 x 2 factorial design included conditions that varied by (a) the presence or absence of documented organic evidence for the pain, (b) cooperative vs. confrontational parent-teacher interactions, and (c) the presence or absence of communication from the medical team. Teachers rated pain severity and impairment, relief from classroom responsibilities, extent of accommodations the student would require in school, and sympathy for the student and family.

RESULTS

Documented medical evidence supporting the pain was the most influential factor affecting teachers' responses to pain. Parental attitude also influenced responses. Communication from the medical team influenced teachers' decisions about relief from responsibilities but did not affect other reactions.

CONCLUSIONS

Teachers' responses to students with pain are influenced by situational factors. Efforts to increase school functioning in youth with chronic pain should incorporate attempts to help teachers respond to pain adaptively.

The role of mental health professionals in multidisciplinary pain rehabilitation programs

The traditional roles of psychologists and mental health therapists are challenged by the comprehensive treatment necessary for patients being treated in multidisciplinary pain rehabilitation programs (MPRPs). Mental health professionals within MPRPs provide direct clinical care but also guide the biopsychosocial model of pain management and cognitive-behavioral interventions for multiple disciplines. Illustrated by a case example of a patient who has complex chronic pain, this article discusses the biopsychosocial approach to pain treatment, structure of multidisciplinary care, major roles of mental health professionals in MPRPs, complexities of treating patients who have pain, and challenges in collaborating with multiple disciplines.

Trustworthiness as a Clinical Variable: The Problem of Trust in the Management of Chronic, Nonmalignant Pain

The subjective nature of pain leads to many treatment difficulties. These problems can often be resolved if we know that the patient is trustworthy. Trustworthiness should be assessed as a distinct clinical variable. This is more easily achieved if we examine the three components of trustworthiness: the patient's subjective reports, which we call testimony; the reason that the patient seeks treatment, which we call motive; and the patient's adherence with efforts to get well, which we call responsibility. Because of difficulties with assessing testimony and motive, we propose that establishing the patient's responsibility is the key to assessing trustworthiness.

Plasticity and functional recovery in neurology

Experiments on patients with phantom limbs suggest that neural connections in the adult human brain are much more malleable than previously assumed. Three weeks after amputation of an arm, sensations from the ipsilateral face are referred to the phantom; this effect is caused by the sensory input from the face skin 'invading' and activating deafferented hand zones in the cortex and thalamus. Many phantom arms are 'paralysed' in a painful position. If a mirror is propped vertically in the sagittal plane and the patient looks at the reflection of his/her normal hand, this reflection appears superimposed on the 'felt' position of the phantom. Remarkably, if the real arm is moved, the phantom is felt to move as well and this sometimes relieves the painful cramps in the phantom. Mirror visual feedback (MVF) has shown promising results with chronic regional pain syndrome and hemiparesis following stroke. These results suggest two reasons for a paradigm shift in neurorehabilitation. First, there appears to be tremendous latent plasticity even in the adult brain. Second, the brain should be thought of, not as a hierarchy of organised autonomous modules, each of which delivers its output to the next level, but as a set of complex interacting networks that are in a state of dynamic equilibrium with the brain's environment. Both principles can be potentially exploited in a clinical context to facilitate recovery of function.

Computed tomography guided lumbar sympathetic block for complex regional pain syndrome in a child: a case report and review

The aim of this paper is to describe the first reported use of computed tomography (CT) guided lumbar sympathetic block as treatment of a case of complex regional pain syndrome (CRPS) in a child. The potential aetiology of CRPS is discussed in relation to the mechanism of action of local anaesthetics used in the block. Based on the successful treatment of this child and the documented success of its use in adults, we conclude that despite the minimal dose of radiation given, CT guided lumbar sympathetic block is an important treatment option in CRPS in children.

Mirror-like spread of chronic pain

The spread of chronic pain from its initial site of presentation is common, but the mechanisms of the spread are unknown. Here the authors present neurophysiologic evidence of altered interhemispheric conduction in a patient with a mirror-like spread of complex regional pain syndrome symptoms.

Is successful rehabilitation of complex regional pain syndrome due to sustained attention to the affected limb? A randomised clinical trial

In complex regional pain syndrome (CRPS1) initiated by wrist fracture, a motor imagery program (MIP), consisting of hand laterality recognition followed by imagined movements and then mirror movements, reduces pain and disability, but the mechanism of effect is unclear. Possibilities include sustained attention to the affected limb, in which case the order of MIP components would not alter the effect, and sequential activation of cortical motor networks, in which case it would. Twenty subjects with chronic CRPS1 initiated by wrist fracture and who satisfied stringent inclusion criteria, were randomly allocated to one of three groups: hand laterality recognition, imagined movements, mirror movements (RecImMir, MIP); imagined movements, recognition, imagined movements (ImRecIm); recognition, mirror movements, recognition (RecMirRec). At 6 and 18 weeks, reduced pain and disability were greater for the RecImMir group than for the other groups (P<0.05). Hand laterality recognition imparted a consistent reduction in pain and disability across groups, however, this effect was limited in magnitude. Imagined movements imparted a further reduction in pain and disability, but only if they followed hand laterality recognition. Mirror movements also imparted a reduction in pain and disability, but only when they followed imagined movements. The effect of the MIP seems to be dependent on the order of components, which suggests that it is not due to sustained attention to the affected limb, but is consistent with sequential activation of cortical motor networks.

Plasma endothelin-1 levels in patients with complex regional pain syndrome

The clinical characteristics of complex regional pain syndrome (CRPS)--spontaneous and stimulus-evoked pain, autonomic abnormalities, motor dysfunction, and trophic changes in the affected limb--are well known. However, its pathogenesis is unclear, and the diagnosis is often delayed, in part due to lack of objective laboratory tests. Endothelin-1 (ET-1) is a potent vasoconstrictor that has recently been shown to produce pain, allodynia, edema, and muscle weakness, as well as to exert a direct excitatory effect on nociceptive afferents. Furthermore, new evidence indicates that ET-1 is involved in various cancer- and non-cancer-related painful conditions. The aim of the present explorative study was to determine the ET-1 plasma levels in patients with CRPS in an attempt to identify a 'laboratory marker' for CRPS and to search for evidence suggesting that ET-1 may be involved in the pathogenesis of CRPS. ET-1 plasma levels were determined in 20 severely affected CRPS patients, in eight patients with non-CRPS chronic painful conditions, and in 10 healthy volunteers. The results showed that there were no significant differences in ET-1 plasma levels between the three groups. We conclude that the plasma level of ET-1 cannot be regarded as a 'marker' for CRPS. Yet, the possibility that ET-1 is involved in the pathophysiology of CRPS has not been excluded and deserves further investigation.

Increased systemic catecholamines in complex regional pain syndrome and relationship to psychological factors: a pilot study

We have demonstrated that subjects with complex regional pain syndrome (CRPS) have asymmetric venous pool plasma concentrations of norepinephrine (NE) when affected and unaffected limbs are compared, with most demonstrating decreased NE levels in the affected limb. This pilot study explored whether systemic venous plasma catecholamine levels in CRPS subjects with sympathetically maintained pain (SMP) differ from those found in healthy volunteers. We also explored whether catecholamine levels were correlated with scores on psychometric measures of depression, anxiety, and personality. Venous blood samples from 33 CRPS/SMP patients (from unaffected limbs) and 30 healthy control subjects were assayed for plasma NE and epinephrine (E) concentrations. Plasma NE levels were significantly higher in the CRPS group (P < 0.001). Statistical comparisons of E levels across groups did not achieve significance (P < 0.06), although 52% of CRPS/SMP patients had E levels exceeding the 95% confidence interval based on control data. Significant positive correlations were found between E levels and scores on the Beck Depression Inventory and Scales 1, 3, and 6 on the Minnesota Multiphasic Personality Inventory-2 (all P < 0.05). This preliminary work suggests that increased NE and E levels in CRPS/SMP patients may result from the pain of CRPS, consequent affective distress, or both. Alternatively, our findings could reflect premorbid adrenergic hyperactivity caused by affective, endocrine, or other pathology, which might predispose these individuals to develop the syndrome. Definitive studies are needed to examine these hypotheses in detail.

Impaired self-perception of the hand in complex regional pain syndrome (CRPS)

To investigate neglect, extinction, and body-perception in patients suffering from complex regional pain syndrome (CRPS). So-called 'neglect-like' symptoms have been reported in CRPS, however no studies have yet analyzed this phenomenon which might substantiate the theory of the central nervous system involvement in the pathophysiology of CRPS. A total of 114 patients with CRPS of the upper limb underwent bedside neurological examination. 'Neglect-like' symptoms were determined by asking all patients what kind of feeling they had toward the affected hand (feeling of foreignness). Hemispatial neglect was tested with the line bisection task in 29 patients and sensory extinction to simultaneous stimulation in 40 patients. The ability to identify fingers after tactile stimulation was tested in 73 patients. Independently of the affected side and disease duration, 54.4% of the patients reported that their hand felt 'foreign' or 'strange'. The ability to identify fingers was impaired in 48% on the affected hand and in 6.5% on the unaffected hand ( X(2) = 33.52, df = 1, p < 0.0001). These findings were related to pain intensity, illness duration and the extent of sensory deficits. No typical abnormalities indicating neglect were found in the line bisection test. Sensory extinction was normal in all patients. A large proportion of CRPS patients have disturbances of the self-perception of the hand, indicating an alteration of higher central nervous system processing. There are no indicators that classic neglect or extinction contribute to these findings. Physical therapy of such patients should take this observation into consideration.

Chronic pain patients are impaired on an emotional decision-making task

Chronic pain can result in anxiety, depression and reduced quality of life. However, its effects on cognitive abilities have remained unclear although many studies attempted to psychologically profile chronic pain. We hypothesized that performance on an emotional decision-making task may be impaired in chronic pain since human brain imaging studies show that brain regions critical for this ability are also involved in chronic pain. Chronic back pain (CBP) patients, chronic complex regional pain syndrome (CRPS) patients, and normal volunteers (matched for age, sex, and education) were studied on the Iowa Gambling Task, a card game developed to study emotional decision-making. Outcomes on the gambling task were contrasted to performance on other cognitive tasks. The net number of choices made from advantageous decks after subtracting choices made from disadvantageous decks on average was 22.6 in normal subjects (n = 26), 13.4 in CBP patients (n = 26), and -9.5 in CRPS patients (n = 12), indicating poor performance in the patient groups as compared to the normal controls (P < 0.004). Only pain intensity assessed during the gambling task was correlated with task outcome and only in CBP patients (r = -0.75, P < 0.003). Other cognitive abilities, such as attention, short-term memory, and general intelligence tested normal in the chronic pain patients. Our evidence indicates that chronic pain is associated with a specific cognitive deficit, which may impact everyday behavior especially in risky, emotionally laden, situations.

Prospective examination of pain-related and psychological predictors of CRPS-like phenomena following total knee arthroplasty: a preliminary study

We hypothesized that preoperative emotional distress and pain intensity would predict the occurrence of signs and symptoms of complex regional pain syndrome (CRPS) following total knee arthroplasty (TKA). Depression (Beck Depression Inventory, BDI), anxiety (State Trait Anxiety Inventory, STAI), pain (McGill Pain Questionnaire-Short Form, MPQ), and signs/symptoms meeting IASP criteria for CRPS were assessed preoperatively, and at 1-, 3-, and 6-months postoperatively in 77 patients undergoing TKA. The prevalence of subjects fulfilling CRPS criteria was 21.0% at 1 month, 13.0% at 3 months, and 12.7% at 6 months postoperative. Higher preoperative scores on the STAI predicted positive CRPS status at 1-month follow-up (P<0.05), with a similar non-significant trend for preoperative BDI scores (P<0.10). Diagnostic sensitivity for the STAI was good (0.73), with moderate specificity (0.56). Neither measure predicted CRPS at later follow-up (P>0.10). Greater preoperative pain intensity predicted positive CRPS status at 3-month (MPQ-Sensory and MPQ-Affective; P<0.01) and 6-month (MPQ-Sensory) follow-up (P<0.01), but not at 1-month (P>0.10). Diagnostic sensitivity was high (0.83-1.00), with moderate specificity (0.53-0.60). Post-TKA patients with CRPS were more depressed at 1-month follow-up (P<0.05) and more anxious at 6-month follow-up (P<0.05) than patients with ongoing non-CRPS pain (all other comparisons non-significant, P>0.10). Overall, results indicate that CRPS-like phenomena occur in a significant number of patients early post-TKA; however, it is not associated with significantly greater complaints of postoperative pain. There appears to be a modest utility for preoperative distress and pain in predicting CRPS signs and symptoms following TKA, although false positive rates are relatively high.

Das komplexe regionale Schmerzsyndrom

Since the term "complex regional pain syndromes" (CRPS) was introduced based on a revised taxonomy for disorders previously called reflex sympathetic dystrophy and causalgia in 1995, much knowledge grew up on the understanding and therapy of the disease. This review gives an overview on the clinical characteristics, pathophysiology, diagnostic tools and therapeutic options in CRPS. It will especially focus on recent findings on the role of the sympathetic nervous system, the central nervous system and peripheral inflammatory processes as underlying mechanisms. Although there is no diagnostic gold standard, careful clinical evaluation and additional apparative test procedures are very helpful for the diagnosis. An early and interdisciplinary approach is the basis for an optimal and successful treatment.