Use of a Case Study Method to Explore Sensory Processing Characteristics of Children With Complex Regional Pain Syndrome

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Previously, we showed that serum soluble interleukin-2 receptor (sIL-2R) levels, a marker for T-cell activation, were higher in complex regional pain syndrome (CRPS) patients than in healthy controls, suggesting pathogenic T-cell activation in CRPS. Additionally, sIL-2R levels discriminated well between CRPS and healthy controls with a high sensitivity (90%) and specificity (89.5%), suggesting a possible role for sIL-2R in the diagnosis of CRPS. In order to further validate this marker in the diagnostic workup of CRPS, we conducted this prospective cohort study in which we determined sIL-2R levels in patients that were referred to our tertiary referral center with a suspicion of CRPS in a limb, and subsequently compared sIL-2R levels between the patients that were diagnosed with CRPS (CRPS group) and those who were not (no CRPS group). A group of anonymous blood bank donors were used as a healthy control group. Furthermore, we explored the relationship between sIL-2R and CRPS disease severity using the CRPS severity score. Median sIL-2R levels of both the CRPS group (2809.0 pg/ml; Q3-Q1: 3913.0-1589.0) and no CRPS group (3654.0 pg/ml; Q3-Q1: 4429.0-2095.5) were significantly higher than that of the control group (1515.0 pg/ml; Q3-Q1: 1880.0-1150.0): CRPS vs. controls, p < .001; no CRPS vs. controls, p < 0.001. Serum sIL-2R levels did not differ significantly between the CRPS and no CRPS group. A statistically significant negative correlation was observed between sIL-2R levels and the CRPS severity score (rs = −0.468, p = 0.024). Our results confirm our previous findings of higher sIL-2R levels in CRPS patients than in healthy controls. We further showed that serum sIL-2R cannot differentiate between CRPS and other pain conditions of a limb in a tertiary referral setting. Interestingly, a negative correlation was found between sIL-2R and CRPS disease severity; this finding warrants further research into the relationship between sIL-2R and CRPS disease severity.

Localized hypertrichosis after index finger revascularization and complex regional pain syndrome.

This report aims to describe complex regional pain syndrome (CRPS) type I and type II. CRPS describes a spectrum of painful conditions that have a common presentation, including pain that is disproportionate to the initiating injury or instigating event. Both CRPS type I and type II have a hallmark of allodynia, severe hyperalgesia, edema and skin changes, and abnormal alterations in sudomotor and vasomotor function. CRPS type I was formally identified as reflex sympathetic dystrophy. CRPS type II is a new term for what was formally described as causalgia. The difference between the two is mainly in the type of inciting event rather than clinical presentation: type I does not include obvious nerve injury, whereas type II CRPS occurs with documented nerve injury. CRPS can occur in both the acute setting and as an exacerbation or change in existing chronic pain. Symptoms of CRPS can occur from a wide range of insults or injuries, such as ankle sprain, bug bite, an operation, or after casting. Similarly, the diagnostic criteria for CRPS type I and type II point to a spectrum of clinical and symptom findings, further emphasizing the varied nature and spectrum of the syndrome. No single standard test is available for its diagnosis. Clinical and exam findings are critical in forming the diagnosis for CRPS type I and type II, and there is a clear pattern of pain that needs to be identified early despite the possibility that all criteria may not have been met for diagnosis. Clinical treatment of patients with CRPS and those that may not fit all criteria for CRPS should emphasize functional restoration, pain abatement using appropriate pharmacological medications and interventional treatment, and psychological therapy. Patients with CRPS need a customized approach to their treatment, and care must be taken to address these needs early to provide the best outcomes. CRPS can progress rapidly if there is a failure in specialized functional restoration and rest therapeutic treatment to help musculoskeletal function.

SummaryIntroduction: Complex regional pain syndrome (CRPS) is a relatively rare disorder, but one that is extremely serious for the affected patient. It usually occurs in the area distal to a primary limb injury. The clinical symptoms and the pain are out of all proportion to the inciting event and in approximately 10 % of CRPS patients, there is no triggering event at all. CRPS leads to long-term disability and high treatment and follow-up costs In about half of those affected.Clinical symptoms: Two forms exist. In CRPS type 1, no nerve lesions are present, whereas in CRPS type 2, injury has occurred to a nerve or the main branch of a nerve. However, in terms of their clinical course, there is no difference between the two forms. Approximately 90 % of all cases involve CRPS type 1, formerly known as “Sudeck’s atrophy”. The cardinal symptom is pain. In addition, trophic disturbances, such as swelling, local skin discolouration or asymmetric skin temperatures, can also occur. Impaired mobility and function of the affected limb also occur frequently and are very difficult to treat.Diagnosis: Initially, it can be difficult to distinguish between CRPS and a normal post-traumatic course. Subsequently, the severe symptoms are out of all proportion to the inciting event. The diagnosis of CRPS is based mainly on the clinical symptoms. The Budapest criteria help to confirm the diagnosis.Therapy: Early and interdisciplinary rehabilitation is of crucial importance in CRPS treatment. Occupational therapy and physiotherapy are supplemented by good analgesic management and psychological support, if required. Analgesia should be based on the WHO pain ladder. Methadone is of proven efficacy in cases of severe hyperalgesia and gabapentin or pregabalin are used to treat refractory pain. Bisphosphonates have shown a good analgesic effect, particularly in patients with confirmed bone lesions. Chronic oedema and inflammation may require short-term steroid administration. A further clinical goal is the avoidance of sequelae, such as osteoporosis. Patients with suspected CRPS should be referred to a multidisciplinary treatment team, preferably one with considerable experience in treating this clinical presentation. One physician should coordinate the patient’s treatment. The earlier the treatment is started, the better the prognosis.

ABSTRACTBackgroundGiven the impact of chronic pain on cognition, CRPS may affect specific cognitive functions. However, cognitive functioning is rarely assessed in CRPS, and previous studies have examined only limited domains. As a result, it remains unclear which cognitive functions are affected and whether impairments are CRPS‐specific. This study comprehensively evaluates cognition in CRPS and compares it to carpal tunnel syndrome (CTS) to determine whether cognitive dysfunction is specific to CRPS.MethodsAll patients underwent a standardised cognitive assessment consisting of ten tests, evaluating the domains of memory, concentration, executive functioning, social cognition and performance validity. Standardised z‐scores and proportion of low‐performing patients (< −1.5 SD from age‐, sex‐ and education adjusted normative data) were examined. Both patient groups were compared with each other and the expected population proportion.ResultsSixty‐four patients (n = 39 CRPS and n = 25 CTS) with a mean age of 52.5 (range 20–81) were included. Compared with patients with CTS, patients with CRPS had significantly higher pain scores 24 h before and during the visit (p < 0.001). All cognitive test results were similar between the two groups. Z‐scores of both groups were comparable or better than the population norm. Furthermore, proportions of patients with Z‐scores below −1.5 SD were similar or better than expected.ConclusionsOur results consistently showed no cognitive impairment in either patient group. Both groups met or exceeded population norms on all tests. However, despite our clear results, attention should be paid to factors affecting cognition, like depression, anxiety and stress.Significance StatementThis study explores the underexamined cognitive dysfunction in Complex Regional Pain Syndrome (CRPS). Cognitive issues, often reported by CRPS patients, can add to the burden on daily life and quality of life (QoL) but are rarely assessed. By comparing CRPS with CTS, this research examines whether cognitive impairments are specific to CRPS. Identifying these issues may lead to targeted therapies addressing both pain and cognitive challenges, ultimately improving patient outcomes and QoL.

Complex Regional Pain Syndrome (CRPS) is a highly debilitating chronic pain condition characterized by continuous regional pain disproportionate to duration and intensity of the initial damaging stimulus. In CRPS, abnormal perception, transmission, and modulation of pain by nerve cells and the autonomic nervous system induces extreme increases in perceived pain that may be accompanied by swelling, temperature sensitivity, color fluctuations, and/or skin changes. CRPS most commonly affects the extremities but may spread to other limbs or bodily locations. Since there is currently no cure for the underlying processes that play a role in causing this debilitating condition, therapeutic options seek to mitigate some of the symptoms of CRPS to improve quality of life. A recent systematic review found low-quality evidence of efficacy for all currently available CRPS treatments as well as a lack of consensus about first-line treatments. The pathophysiological complexity of CRPS, in addition to the lack of non-invasive, efficacious therapies for this extremely burdensome pain condition, highlights the vital need to explore novel therapeutic options in both research and clinical practice. Photobiomodulation through the repeated application of high-intensity laser therapy in a clinical setting has been shown to modulate nociception, minimize inflammation, and reduce different types of chronic and acute pain. The present case report describes a clinical protocol using laser therapy for CRPS, presents longitudinal pain scores, and summarizes mechanisms of action supporting the subsequent reduction of CRPS symptoms. After a series of laser treatments, the patient showed marked improvement in range of movement, hypersensitivity, pain, and function. Photobiomodulation through high-intensity laser therapy may represent a promising therapy for individuals affected by CRPS, although further randomized, controlled trials are recommended to evaluate efficacy on different disease-affected areas, assess dose-response relationships, and refine optimal treatment frequency.

Objectives: Complex regional pain syndrome (CRPS) is a heterogeneous pain disorder with incompletely understood immunoinflammatory features. This study investigated whether autonomic receptor autoantibodies differentiate CRPS from other chronic pain conditions and healthy controls. Methods: We conducted a cross-sectional analysis of serum samples from patients referred with suspected CRPS. Patients were subsequently classified as having either CRPS or another chronic pain condition, based on the Budapest criteria. Healthy controls were included for comparison. Serum levels of autoantibodies targeting the muscarinic M2 receptor (M2R), β1-adrenergic receptor (β1AR), and the β2-adrenergic receptor (β2AR) were assessed using enzyme-linked immunosorbent assay. All analyses were performed blinded to group assignment. Results: Seventy participants were analyzed (CRPS = 22, other chronic pain = 25, healthy controls = 23). M2R autoantibody levels were higher in both CRPS and other chronic pain compared with healthy controls (mean difference [MD] = 0.37, 95%CI 0.22-0.51; and MD = 0.31 95%CI 0.19-0.44, respectively). β2AR levels were higher in other chronic pain compared with healthy controls (MD = 0.29, 95%CI 0.04-0.54), whereas no significant difference was observed in CRPS (MD = 0.21 95%CI -0.01-0.42). No meaningful differences were observed between CRPS and other chronic pain for any receptor. β1AR levels did not differ between groups. Seropositivity for any autoantibody was 55% in CRPS, 44% in other chronic pain, and 22% in healthy controls. Conclusions: Elevated autonomic receptor autoantibody levels were observed across chronic pain conditions but were not specific for CRPS.

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. Forty-eight people with CRPS participated in this research. 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. 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. 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.

Date Presented 3/31/2017 The field of occupational therapy is continuing to grow and improve treatment techniques and strategies through the use of assistive technology. The purpose of this study was to gain insight into the clinical reasoning behind occupational therapy practitioners’ use of iPads during treatment. Primary Author and Speaker: Megan Edwards Contributing Authors: Carly Cody, Brittany Izer, Shannon Meyerhoff, Carrie Starling, Rebecca Thompson

Physiotherapy is considered in pain medicine to be a key element in the management of Complex Regional Pain Syndrome (CRPS). This is the first paper to document and categorise all physiotherapy intervention methods used as well as evaluate the outcomes of a case series of 18 CRPS patients attending physiotherapy in a prospective, longitudinal study across a region. Outcomes were measured across the region of the South Island of New Zealand over 1 year through independent telephonic interviewing of the pain experience with the McGill Pain Questionnaire-short form, function with Foot Function Index for the lower limb or Disability of the Arm Shoulder and Hand for the upper limb, and quality of life with the World Health Organisation Disability Schedule. Clinical records were accessed for each CRPS participant following discharge from physiotherapy to categorise the intervention methods used. Seventeen participants received intervention for both functional restoration with pain modulation and only one participant received functional restoration with no pain modulation; 12 also received immobilisation with 10 receiving passive interventions. All outcome measures improved significantly by 6 months and were maintained at 1 year. Eighty five percent had their diagnosis of CRPS confirmed within 3 months of their injury; half had fracture as the precipitating injury for their onset of CRPS with a third following soft tissue injury and 11% following surgery. Physiotherapists showed a high variation with the intervention methods used and showed a greater proportion of intervention methods focusing on functional restoration followed by pain modulating interventions. Future research is necessary to define what physiotherapy interventions are efficacious in the management of CRPS.

Dear Editor, The inherent challenges of thoracotomy include neuropathic pain due to the cutting of T3-T10 intercostal nerves, visceral pain of lung parenchymal, somatic pain, and persistent postsurgical pain syndromes (PSPSs).[1] We present a case of a 45-year-old male presented with left-sided upper back pain following left lung pneumonectomy. The perioperative course of the surgery was uneventful. After 1 ½ months of surgery, the patient reported dullness, continuous to intermittently sharp pain, a visual analogue scale (VAS) score of 9–10/10, and pain on wearing clothes, touch, and pressure. The skin on the left upper back was reddish and had local swelling, hyperalgesia, and allodynia to touch, pinprick and on application of brush and pressure [Figure 1a and b]. The left shoulder had limitations in abduction, adduction, and extension. The discomfort in the epigastrium and the left hypogastrium occurred with the intermittent appearance of a lump while eating food and drinking water. The epigastric pain was continuous, with intermittent episodes of vomiting and constipation, and the patient complained of pain while lying down straight. The laboratory parameters and imaging study revealed no active infection. The patient received oral gabapentin/nortriptyline 100/10 mg twice daily, and later, the night dose was gradually increased to 300/10 mg. In addition, oral aceclofenac-paracetamol 100/325 mg twice daily, oral baclofen of 10 mg once daily, and laxatives were prescribed. After one week, the patient reported reduced pain, spasms, discolouration of the affected area, and improvement in shoulder movements [Figure 1c and d]. However, the patient had trouble tolerating sedation and dizziness. At three months of follow-up, the patient received T2-3 sympathetic block under fluoroscopic guidance with 5 ml of ropivacaine 0.2% and dexamethasone 4 mg. The VAS was reduced to 2–3/10. After one month, VAS was 4/10, and a T2-3 sympathetic block was performed with 5 ml solution of 1% lignocaine and dexamethasone 4 mg. During follow-up, the patient is on oral gabapentin/nortriptyline 100/10 mg once daily with a reported VAS of 1–3/10 at one year and has resumed his work with a good quality of life.Figure 1: (a) Complex Regional Pain Syndrome (CRPS) II changes on the upper back in the post-pneumonectomy patient. (b) Swelling/lump formation in the epigastrium (c) Resolution of symptoms of skin colour changes and other features of CRPS II (d) Resolution of swelling/lump formation in the epigastriumIn the present case, the history of surgery and diagnostic features of the International Association for the Study of Pain (IASP) for Complex Regional Pain Syndrome (CRPS) indicated the diagnosis of CRPS II.[2] The first criterion was continuing pain, which was disproportionate to any inciting event. The second criterion was the presence of at least one symptom in three or more symptoms out of sensory, vasomotor, sudomotor (oedema), and motor (trophic) categories as per IASP criteria for CRPS. The third criterion was at least one sign in two or more sensory, vasomotor, sudomotor (oedema), and motor (trophic) categories as per IASP criteria for CRPS. The fourth criterion was that no other diagnosis could explain the signs and symptoms better.[2] The probability for persistent post-surgical pain or myofascial pain was ruled out in view of associated skin changes, oedema, and reduced range of shoulder movement, and CRPS II was the most appropriate diagnosis. The patient had allodynia to touch, temperature change (sub-acute CRPS), pain to deep pressure, limitation of shoulder joint movement, and hyperalgesia to pinprick, and all these resolved after treatment. The visceral changes reported in the upper abdomen can be argued with spasms in myofascial pain and post-surgical persistent pain in isolated symptoms. Still, the IASP criteria of CRPS aptly satisfy the diagnosis in the present case. Moreover, the effect of sympathetic block in the patient confirmed the diagnosis of CRPS.[2,3] The features that make this case unique were the presence of contraction of thoracic inter-costal, anterior abdominal wall muscles, oesophagal smooth muscles, and stomach muscles leading to the abdominal wall muscle spasm, intermittent lump formation, and constipation. T2-T3 sympathetic block may improve visceral muscle pain, but pain relief effects beyond the duration of local anaesthetics are only possible in sympathetic-mediated pain like CRPS and not otherwise.[4] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient consented to the images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Complex Regional Pain Syndrome (CRPS) is a challenging and often disabling condition marked by persistent pain, most commonly in a limb following injury or surgery. It presents with a wide array of symptoms, including intense pain, swelling, alterations in skin color and temperature, motor dysfunction, and trophic changes such as skin and tissue atrophy. While the precise cause of CRPS is not fully understood, it is thought to stem from abnormal nervous system activity, leading to heightened pain sensitivity and inflammatory responses. A thorough understanding of CRPS is essential for accurate diagnosis, effective treatment, and enhancing patients' quality of life.Although attempts have been made to distinguish between acute and chronic CRPS, there are currently no established diagnostic criteria specific to chronic CRPS in medical literature. This ASIPP guidance document offers updated, evidence-based recommendations for the diagnosis and management of Chronic Complex Regional Pain Syndrome (CRPS), with a primary focus on introducing novel, time-based diagnostic criteria specific to the chronic phase. These proposed criteria address significant gaps in the current literature, where existing standards, such as the Budapest Criteria, do not sufficiently differentiate between the acute and chronic stages of the condition. An expert panel convened by the American Society of Interventional Pain Physicians (ASIPP) conducted a comprehensive literature review and employed a structured consensus process to develop recommendations. Acknowledging that the clinical and pathological characteristics of CRPS change significantly beyond 12 months, the panel proposed chronic-specific diagnostic criteria based on disease duration, clinical history, physical examination findings, and optional diagnostic tests. These draft criteria were refined through multidisciplinary input and expert consensus. The diagnostic framework for chronic CRPS consists of four key components:General Criteria - Require fulfillment of the Budapest Criteria for at least 12 months, continued recognition of CRPS as a diagnosis of exclusion, and differentiation from generalized nociplastic pain syndromes.History-Based Criteria - Mandate the presence of at least three out of five specific historical features.Physical Examination Criteria - Include asymmetric limb findings, sensory disturbances, and musculoskeletal changes.Optional Diagnostic Testing - May involve assessments such as intraepidermal nerve fiber density (IENFD) and imaging evidence of regional bone demineralization.This framework builds upon the Budapest Criteria by incorporating time-dependent features of chronic CRPS, including musculoskeletal dystrophy, neurogenic inflammation, and sympathetic dysfunction. Emerging objective tools-such as quantitative sensory testing (QST), skin biopsy for IENFD, functional MRI, and serum biomarkers of neuroinflammation-may further support diagnosis in complex or uncertain cases.Treatment recommendations highlight a multimodal strategy that integrates physical rehabilitation, pharmacologic management of neuropathic pain, sympathetic nerve blocks, and advanced neuromodulation. Emphasis is placed on individualized care pathways tailored to disease stage and patient-specific characteristics. This article presents the first structured, time-sensitive diagnostic criteria for chronic CRPS, aimed at improving diagnostic accuracy and informing treatment strategies. Adoption of these criteria may enhance clinical outcomes and promote further research into the natural history and pathophysiology of CRPS progression.

Background: Complex regional pain syndrome (CRPS) is a disproportionate and persistent, regional pain related to a minor trauma. Although CRPS is not an infrequent condition its pathophysiology remains unknown and leading to underdiagnosis or late diagnosis. The diagnosis is clinical, according to Budapest criteria of the International Association for the Study of Pain. Bone scintigram is the most effective test to support the diagnosis. The aim of this article is to discuss the importance of clinical suspicion for an early CRPS diagnosis in a sprain’s young athlete clinical case. The Case: We present the case of a sixteen-year-old male patient with no medical history who suffered two minor ankle injuries in the right foot. The patient developed severe and persistent pain associated with vasomotor, sudomotor and trophic abnormalities. He remained undiagnosed for 10 months until CRPS diagnosis confirmation supported by a bone scintigram. He received multiple treatments until spontaneous remission in the fourth year of evolution. Discussion: CRPS poses a diagnostic challenge that requires early suspicion to improve treatment outcomes and prognosis. Maintaining a high index of clinical suspicion is crucial, and CRPS should be considered in the evaluation of any persistent pain sport-related injury. Despite extensive research on CRPS conducted in recent decades, this condition may still be unfamiliar to many healthcare providers. Increasing awareness of CRPS among medical professionals can facilitate timely and accurate diagnosis, which is essential for effective management.

Complex regional pain syndrome (CRPS) is a debilitating chronic pain condition that may develop after fractures, surgery, or soft tissue trauma. It is characterized by pain disproportionate to the initial injury, often accompanied by sensory, motor, autonomic, and trophic changes. Despite extensive research, pathophysiology remains unclear, and treatment approaches are varied, with inconsistent supporting evidence. Given its complexity and the potential for chronic disability, identifying effective therapies remains a clinical priority.This review systematically evaluated the analgesic efficacy of pharmacological and non-pharmacological therapies for CRPS, based on randomized controlled trials (RCTs) published between 2003 and 2025. The protocol was developed previously and registered in PROSPERO (CRD420251026503).A structured literature search using a PICO (Population, Intervention, Comparator, Outcome) framework was conducted across MEDLINE, PubMed, and the Cochrane Library. Search terms included “Complex Regional Pain Syndrome,” its earlier term “Reflex Sympathetic Dystrophy,” and intervention-specific keywords. Included were English-language RCTs in adults with clinically diagnosed CRPS (type I or II), assessing pain reduction as the primary outcome and function, quality of life, and pain medication use as secondary outcomes. Two reviewers independently screened and extracted studies. Risk of bias was assessed using the Cochrane Risk of Bias (ROB) 2. Publication bias was evaluated using funnel plots of standard errors and effect sizes.In total, 45 RCTs met the inclusion criteria and included 2,125 patients. Among pharmacological interventions, bisphosphonates showed consistent and significant pain reduction over six months. Intravenous ketamine demonstrated strong short-term analgesia, though findings were limited by small samples, variable protocols, and lack of long-term data. Combinations of local anesthetics and other medications (e.g., lidocaine with citalopram or parecoxib) were especially effective in acute CRPS. Steroid treatments (oral or regional) offered short-term pain relief and functional improvement, particularly in early or post-stroke CRPS.Non-pharmacological therapies also showed promise in reducing CRPS pain. Mirror therapy (MT) and graded motor imagery (GMI) consistently improved pain and motor function, especially when applied early. Pain exposure physical therapy (PEPT) improved range of motion but had a limited impact on overall functional outcomes. Neuromodulation methods, including spinal cord stimulation (SCS), dorsal root ganglion (DRG) stimulation, and transcutaneous electrical nerve stimulation (TENS), provided durable pain relief in select patients but were technically complex and associated with complications, particularly with SCS.In conclusion, CRPS remains a complex and difficult-to-treat condition, with substantial variability in treatment response. RCT evidence supports the use of bisphosphonates, ketamine, and early use of mirror or motor imagery therapies. Neuromodulation via electrical stimulation may benefit select cases but carries procedural risks. Physiotherapeutic strategies offer low-cost, low-risk benefits, especially when started early or combined with pharmacotherapy. However, many studies were limited by small size, short follow-up, or methodological flaws. There is an urgent need for large, high-quality, and mechanistically informed RCTs to guide long-term CRPS management.