Complex regional pain syndrome - Autoimmune or functional neurologic syndrome

Ketamine Infusion for Complex Regional Pain Syndrome Treatment: A Narrative Review

PURPOSE OF REVIEW

Complex Regional Pain Syndrome (CRPS) is a neuropathic pain disorder characterized by pain disproportionate to the inciting event that is constant for an extended duration. Numerous treatment options for this condition have been explored with unsatisfactory results in many cases. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist typically used as an anesthetic and analgesic, presents a promising potential treatment for CRPS in patients who fail to respond to traditional therapies.

RECENT FINDINGS

Numerous studies report significant improvement in the degree of pain, mobility of extremities, and other parameters after ketamine infusion in patients with CRPS. Although adverse effects were not reported often, some subjects experienced nausea, vomiting, headache or psychotropic or psychomimetic symptoms which could be mitigated with cessation of the drug. Although more research is needed to determine optimal dosing and duration, ketamine seems to be a safe and effective treatment for refractory cases of CRPS.

CONCLUSION

The present investigation summarizes existing knowledge and research surrounding ketamine infusions for CRPS to provide a well-rounded depiction of advantages and disadvantages for physicians who may be considering it for patients with this challenging and complex condition.

The role of fatigue in patients with complex regional pain syndrome

BACKGROUND AND PURPOSE

Fatigue affects patients across a variety of neurological diseases, including chronic pain syndromes such as complex regional pain syndrome (CRPS). In CRPS, fatigue is often underestimated, as the focus lies in the assessment and managing of pain and sensorimotor deficits. This study aimed to investigate the prevalence, characteristics, and influence of fatigue on CRPS severity and quality of life in these patients. Such insights could enhance the clinical management of this challenging condition.

METHODS

In this prospective study, 181 CRPS patients and 141 age and gender-matched individuals with injury but without chronic pain were interviewed using the Fatigue Scale for Motor and Cognitive Function to assess fatigue. Depressive symptoms and quality of life (QoL) were also evaluated as additional outcome measures. Statistical analysis was performed to examine differences in fatigue prevalence between the groups, as well as associations with CRPS severity, pain levels, and clinical phenotype. In addition, best subsets regression was used to identify the primary factors influencing QoL. Fatigue was tested in a mediation analysis as a mediator between pain and depression.

RESULTS

CRPS patients showed significantly higher fatigue levels compared to controls (CRPS: 75 [IQR: 57-85] vs. controls: 39 [IQR: 25-57]). Based on the FSMC, 44.2% in the control group experienced fatigue, while 85% of patients with CRPS experienced fatigue (p < 0.001), of which 6% were mild, 15% moderate, and 67% severe. In CRPS severe fatigue was associated with higher pain intensities compared to no fatigue (pain at rest: p = 0.003; pain during movement: p = 0.007) or moderate fatigue (pain during movement: p = 0.03). QoL in our cohort was mainly influenced by pain (pain during movement: adj.R2 = 0.38; p < 0.001, pain at rest: Δadj.R2 = 0.02, p = 0.007) and depressive symptoms (Δadj.R2 = 0.12, p < 0.001). Subsequent analyses indicated that pain and depressive symptoms primarily impact QoL in CPRS whereas fatigue may exert an indirect influence by mediating the connection between pain and depression (p < 0.001).

CONCLUSIONS

This pioneering study investigates the prevalence of fatigue in CRPS patients and its relation to disease characteristics. Our results indicate a high prevalence of severe fatigue, strongly correlated with pain intensity, and its importance in the interaction between pain and depression in CRPS. These findings underscore the significant role of fatigue as a disease factor in CRPS. Therefore, the evaluation of CRPS-related disability should include a standardized assessment of fatigue for comprehensive clinical management.

Complex regional pain syndrome: diagnostic challenges and favorable response to prednisolone

Complex regional pain syndrome (CRPS), characterized by severe and disproportionate pain, is a rare and debilitating condition. Due to its rarity, evidence-based treatment guidelines remain limited, creating a challenge for clinicians. We present the case of a 20-year-old female with CRPS type 1 of the right hand. Her pain, initially triggered by a minor trauma, had persisted for three months. The patient demonstrated severe pain, swelling, hyperesthesia, and restricted range of motion. Despite multiple hospital visits, her symptoms did not improve until she was diagnosed with CRPS and treated with oral prednisolone. A dosage of 40 mg daily led to a dramatic response within 10 days. Our report emphasizes the importance of recognizing CRPS and highlights the potential of prednisolone as a treatment option, particularly in resource-limited settings, where more specialized interventions may be unavailable. Further research is essential to establish a stronger evidence base for the use of steroids in CRPS management.

An Unusual Presentation of Complex Regional Pain Syndrome Type 1

Complex regional pain syndrome (CRPS) is a chronic neurologic painful disorder usually present after a traumatic insult. It is divided into two subtypes based on the absence of a significant nerve injury: type 1 or dystrophy and type 2 or causalgia. The exact mechanism still needs to be fully understood. The management of CRPS requires a multidisciplinary team approach with a rehabilitation program and physical and occupational therapies. We present a case report of a 22-year-old Saudi female with no medical or surgical history who presented to the clinic with severe pain, swelling, and discoloration in the left lower limb associated with unusual symptoms of non-epileptic convulsion attack and short-term memory loss for three years that increased in intensity. There was marked swelling and discoloration of the left lower limb, which was more significant at the foot, and the limb was tender and warm to the touch and allodynia. A slight touch to the limb led to a whole-body non-epileptic convulsion lasting for less than 30 seconds and loss of short-term memory and consciousness following the convulsion attack. A multidisciplinary team primarily managed the patient. In this case, the rarity and refractory to medical management emphasize the importance of understanding the different therapeutic modalities in managing this syndrome. However, more studies are warranted to understand the exact cause, pathogenesis, and available treatment options.

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.

Amputation for Complex Regional Pain Syndrome: Meta-Analysis and Validation of a Histopathology Scoring System

OBJECTIVE

Pathology can provide crucial insights into the etiology of disease. The goal of this review is to evaluate the rigor of histopathology reports of Complex Regional Pain Syndrome (CRPS).

METHODS

A systematic search of multiple databases identified papers that described amputation for CRPS with pathology findings. Control pathology articles were randomly chosen from the same journals. Landmark articles in Surgical Pathology were previously identified. Papers were categorized by the use of histology: Anatomic (microscopic description), Diagnostic (binary result), and Substrate (special studies only). A novel Histopathology Score assigned 1 point for each of 10 History elements and 15 Pathology elements. All articles were scored and analyzed by appropriate statistics.

RESULTS

The search identified 22 CRPS, 50 Control and 50 Landmark articles. Multivariable analysis of the Pathology Score showed a significantly higher score for Anatomic vs Non-Anatomic papers (Incidence Rate Ratio (IRR) 1.54, P < .001) and Landmark vs CRPS articles (IRR 1.39, P value .003). CRPS papers reported some elements infrequently: diagnostic criteria (31.8%), routine stain (50%), any clinic-pathologic correlation (40.9%), and sample size >2 (27.3%).

CONCLUSIONS

The Pathology Score is a useful quality assessment tool to evaluate studies. As expected, Anatomic papers scored significantly higher than Non-Anatomic papers. CRPS papers had small sample sizes (median 1) and infrequent reporting of diagnostic criteria, routine stain, any clinical pathologic correlation. These particular elements are crucial for analyzing and reviewing pathologic features. The analysis explains why it is quite difficult to write a meaningful systematic review of CRPS histology at this time.

Central Sensitization and Psychological State Distinguishing Complex Regional Pain Syndrome from Other Chronic Limb Pain Conditions: A Cluster Analysis Model

Complex regional pain syndrome (CRPS) taxonomy has been updated with reported subtypes and is defined as primary pain alongside other chronic limb pain (CLP) conditions. We aimed at identifying CRPS clinical phenotypes that distinguish CRPS from other CLP conditions. Cluster analysis was carried out to classify 61 chronic CRPS and 31 CLP patients based on evoked pain (intensity of hyperalgesia and dynamic allodynia, allodynia area, and after-sensation) and psychological (depression, kinesiophobia, mental distress, and depersonalization) measures. Pro-inflammatory cytokine IL-6 and TNF-α serum levels were measured. Three cluster groups were created: ‘CRPS’ (78.7% CRPS; 6.5% CLP); ‘CLP’ (64.5% CLP; 4.9% CRPS), and ‘Mixed’ (16.4% CRPS; 29% CLP). The groups differed in all measures, predominantly in allodynia and hyperalgesia (p < 0.001, η² > 0.58). ‘CRPS’ demonstrated higher psychological and evoked pain measures vs. ‘CLP’. ‘Mixed’ exhibited similarities to ‘CRPS’ in psychological profile and to ‘CLP’ in evoked pain measures. The serum level of TNF-αwas higher in the ‘CRPS’ vs. ‘CLP’ (p < 0.001) groups. In conclusion, pain hypersensitivity reflecting nociplastic pain mechanisms and psychological state measures created different clinical phenotypes of CRPS and possible CRPS subtypes, which distinguishes them from other CLP conditions, with the pro-inflammatory TNF-α cytokine as an additional potential biomarker.

Managing Psychiatric Symptoms in Patients with Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a rare but debilitating chronic pain condition of the extremities, which often develops after an injury. Its multifactorial pathophysiology includes the immune and nervous systems and, potentially, autoimmune, genetic, and psychological factors. Psychiatric illnesses can be comorbid with CRPS, including mood disorders, anxiety disorders, insomnia, substance use disorder, personality disorders, and somatic symptom disorder. This article discusses these psychiatric symptoms and offers treatment guidance.

Complex Regional Pain Syndrome in Athletes: Scoping Review

Background and Objectives: Complex regional pain syndrome (CRPS) is a chronic condition characterized by disproportionate regional pain, usually affecting distal limbs, that follows trauma or surgery. Athletes may develop CRPS because of exposure to traumatic or overuse injuries. The aim of the present study is to review the available literature about CRPS type 1 in athletes. Materials and Methods: We searched two online databases (PubMed and Web of Science), selecting papers aiming at investigating CRPS type 1 (algodystrophy) in athletes. The analysis of databases was made considering original articles published until 30 June 2021, written in English. Results: Fifteen papers (12 case reports, 3 case series) were selected for a total of 20 clinical cases (15 females, 5 males), aged between 10 and 46 years (mean age 18.4 ± 9.8 standard deviation years). Patients included practiced different types of sport (soccer, athletics, gymnastics, basketball). The most involved anatomical sites were lower limbs, and time to diagnosis ranged from 2 days to 4 years. The most used treatments were pharmacological and physical therapies, but sometimes invasive approaches, as regional nerve, or lumbar sympathetic blocks, were provided. The main assessed outcomes were return to activity and pain. Conclusions: Our review suggests a higher prevalence of CRPS type 1 in younger people and in lower limbs than in general population but confirms the higher prevalence in females. However, the number of studies addressing CRPS in athletes is limited, as well as the number of involved patients, considering that only few and heterogeneous case reports were published about this topic. Moreover, the high prevalence of old studies (only 5 available studies in the last 10 years) might have influenced the choice of both assessment tools and management strategies. Despite these limitations, athletes showing disproportionate pain after sport-related injury should be promptly evaluated and treated through a multidimensional approach to avoid long-term consequences of algodystrophy.

Bier block as a successful management of a patient with intractable complex regional pain syndrome (CRPS) type 1: A case report

Bier block was successful in the pain management of complex regional pain syndrome (CRPS) type 1.