Impact of Spinal Cord Stimulation on Sensory Characteristics in Complex Regional Pain Syndrome Type I: A Randomized Trial

Background: A randomized trial was performed to assess the effect of spinal cord stimulation (SCS) on detection and pain thresholds for pressure, warmth, and cold and on the extent of mechanical hyperalgesia in patients with chronic complex regional pain syndrome type I.

Methods: Fifty-four chronic complex regional pain syndrome type I patients were randomized to receive both SCS and physical therapy (SCS+PT; n = 36), or to receive only physical therapy (PT; n = 18). Twenty-four SCS+PT patients responded positively to trial stimulation and underwent SCS implantation. During a 12-month follow-up period, six quantitative sensory testing sessions were performed. The main analysis compared 24 SCS patients with 29 nonimplanted patients-one PT patient was excluded.

Results: SCS showed no effect on detection thresholds for warmth and cold or on pain thresholds for any sensation. The pressure detection threshold initially increased by SCS, but after 3 months, pressure detection thresholds returned to normal. Mechanical hyperalgesia, both dynamic and static, was reduced slightly with SCS.     

Quality of life in adults with childhood-onset of Complex Regional Pain Syndrome type I

Introduction

The clinical presentation of Complex Regional Pain Syndrome type I (CRPS I) in children differs compared to the presentation in adults. Reported results of treatment of CRPS I in children are usually more favourable and seem better than the reported treatment of adults with CRPS I. We investigated the quality of life (QoL) in adults who have been treated for childhood-onset CRPS I.

Methods

We performed a retrospective chart review on signs, symptoms and treatment of all patients, seen and treated for CRPS I in childhood (age <16 years). At one time point a survey was sent by mail to all adult patients with onset CRPS I in childhood with a postal reminder after one month. The first part of the survey consisted of questions focused on the experience of chronic pain and other current complaints in the affected extremity. The second part consisted of a generic-health-related quality of life instrument (SF-36).

Results

Forty-two patients (75%) responded to our survey. The median follow-up period was 12 years (SD 4.7; range 2-22). Fifty-two percent of all patients complained about pain at the time of follow-up. Of the 12 symptoms and signs, 4 are improved, 1 is worse and the remainder are unchanged. Fifteen patients experienced one or more documented relapses. General health and physical functioning (2 out of 8 scales on the SF 36) were lower in patients compared to those of the literature.

Conclusion

In contrast to the literature, the prognosis of childhood-onset CRPS I seems less favourable than usually reported, and is comparable to the prognosis of the adult-onset CRPS I in view of a decreased quality of life and a large relapse percentage (33%) at long-term follow-up.     

Determinants of Complex Regional Pain Syndrome Type I among Radial Head Fracture Patients with Unilateral Arthroplasty

ObjectiveThis study aims to assess the proportions of complex regional pain syndrome type I (CRPS I) in radial head fracture patients undergoing unilateral arthroplasty and to explore associated factors.MethodsThis is a prospective observational study. From March 2016 to May 2019, a total of 221 adult patients with radial head fracture patients were included in consecutive studies and completed the 1‐year follow‐up. All patients were treated by unilateral arthroplasty. At each follow‐up visit, the visual analogue scale was used to measure patients'' pain level. Occurrence of CRPS I, which was diagnosed by Budapest criteria, was the main outcome collected at baseline and the 1‐, 3‐, 6‐, and 9‐month follow‐ups. The baseline data were collected before surgery and included demographic and clinical data. Independent t‐tests and χ ² tests were used as univariate analyses to compare the baseline data of patients with and without CRPS I. Multivariate analysis (Backword‐Wald) was used to identify factors independently associated with CRPS I.ResultsThe proportion of CRPS I cases among radial head fracture patients undergoing unilateral arthroplasty was 11% (n = 24). A total of 19 (79%) patients were diagnosed with CRPS I within 1 month after surgery. Multivariable logistic regression analysis revealed that female gender (odds ratios [OR]: 1.537; 95% confidence interval [CI]: 1.138–2.072), age younger than 60 years (OR: 1.682; 95% CI: 1.246–2.267), moderate and severe Mayo Elbow Performance Score (MEPS) pain (OR: 3.229; 95% CI: 2.392–4.351) and anxiety (OR: 83.346; 95% CI: 61.752–112.320) were independently associated with CRPS I.ConclusionsThis exploratory study reported that the incidence of CRPS I developing after radial head arthroplasty was 11%. Female sex, younger age, moderate and severe MEPS pain and anxiety patients seems more likely to develop CRPS I.     

复杂性区域疼痛综合征诊疗进展

复杂性区域疼痛综合征（complex regional pain syndrome,CRPS）是对一系列疼痛状态的描叙．其特点为似乎与任何已知的创伤或其它损伤过程中时间及程度不相符的局部持续性疼痛（自发／或诱发）。其病因尚未完全明确,诊断主要根据临床症状和相关辅助检查,而治疗则常常需要多学科多技术的联合。现本文就其诊疗进展做一简要综述。     

Conservative therapy for Complex Regional Pain Syndrome Type I in a paediatric patient: a case study

Complex regional pain syndrome (CRPS) is a term that describes a variety of chronic pain conditions that are believed to result from dysfunction in the central or peripheral nervous systems. Typical features include dramatic changes in the colour and temperature of the skin over the affected limb or body part, accompanied by an intense pain which is out of proportion to the injury thought responsible. Skin sensitivity, sweating, and swelling are also commonly involved. This case study presents subjective reports of changes in pain and extremity weight bearing capacity in an 8 year-old child with Chronic Region Pain Syndrome Type I. The changes reported occurred over a 12 week conservative course of treatment which included manipulation, nutritional supplementation and rehabilitation. The patient was able to regain full control of her legs and full weight bearing after 3 weeks of treatment.     

Continuous Peripheral Nerve Blocks at Home for Treatment of Recurrent Complex Regional Pain Syndrome I in Children

Background: Recurrent complex regional pain syndrome I is not rare in the pediatric population. The authors conducted this study to evaluate the efficacy of continuous peripheral nerve blocks with elastomeric disposable pumps associated with initial Bier blocks for the treatment of recurrent complex regional pain syndrome I in children.

Methods: After parental informed consent, 13 children who did not respond to conventional complex regional pain syndrome treatment were included (mean age, 13 yr; range, 9-16 yr). After general anesthesia, peripheral nerve block was performed using 0.5 ml/kg lidocaine, 1%, with epinephrine and 0.5% ropivacaine injected in the peripheral nerve block catheter. Then, a 20-min Bier block was performed using a tourniquet and 0.2 ml/kg lidocaine, 1%; 3 ml/kg hydroxyethyl starch 130/06; and 5 mg/kg buflomedil injected intravenously. A solution of 0.1 ml [middle dot] kg-1 [middle dot] h-1 continuous ropivacaine, 0.2%, was infused through the catheter using an elastomeric pump for 96 h. Need for rescue analgesia, occurrence of side effects, and status of motor and sensory block were recorded at hours 1, 6, 12, 24, 48, 72, and 96. Children and parents completed a satisfaction assessment. All of the children had follow-up visits after 2 months.

Results: Postoperative analgesia was excellent. The median pain score was 0 for each period studied. Motor blockade was minimal before 12 h (median, 1) and absent thereafter. One child needed rescue analgesia. All children were able to walk easily after the initial 24-h period (walking score, > 4). Children and parents were all satisfied. Children returned home under parental surveillance beginning in the 24th hour. Neither peripheral nerve block nor Bier block caused side effects. After 2 months, none of the children exhibited any clinical symptom of recurrent complex regional pain syndrome.     

Lower Extremity Complex Regional Pain Syndrome: Long-term Outcome after Surgical Treatment of Peripheral Pain Generators

We undertook a retrospective study to evaluate the hypothesis that complex regional pain syndrome (CRPS) I, known as the “new” reflex sympathetic dystrophy, persists because of undiagnosed injured joint afferents, cutaneous neuromas, or nerve compressions, and is, therefore, a misdiagnosed form of CRPS II, which is known as the “new” causalgia. We used a research protocol, with institutional review board approval, to review medical records for the purpose of identifying 30 patients with lower extremity reflex sympathetic dystrophy, based on their history, physical examination, neurosensory testing, and response to peripheral nerve blocks, who were treated surgically at the level of the peripheral nerve. In this report, we describe long-term outcomes in 13 of these patients who were followed up for a minimum of 24 months (mean, 47.8 months; range, 25-90 months). Based primarily on the results of physical examination and the response to peripheral nerve blocks, surgery included a combination of joint denervation, neuroma resection plus muscle implantation, and neurolysis. Outcomes were measured in terms of decreased pain medication usage and recovery of function, and the results were excellent in 7 (55%), good in 4 (30%), and poor (failure) in 2 (15%) of the patients. Based on these results, we concluded that most patients referred with a diagnosis of CRPS I have continuing pain input from injured joint or cutaneous afferents, and chronic nerve compression, which is indistinguishable from CRPS II, and amenable to successful treatment by means of an appropriate peripheral nerve surgical strategy.     

Concentration-Effect Relationship of Intravenous Lidocaine on the Allodynia of Complex Regional Pain Syndrome Types I and II

Background: Several lines of evidence suggest that neuropathic pain (including Complex Regional Pain Syndrome [CRPS] I and CRPS II) is mediated in part by an increase in the density of voltage-sensitive sodium channels in injured axons and the dorsal root ganglion of injured axons. This study sought to characterize the effects of intravenous lidocaine (a sodium channel blocker) on acute sensory thresholds within the painful area and the size of the painful area in patients suffering from CRPS I and II.

Methods: This study used a randomized, double-blind, placebo-controlled design in 16 subjects suffering from CRPS I and II with a prominent allodynia. Each subject received an intravenous infusion of lidocaine and diphenhydramine separated by 1 week. A computer-controlled infusion pump targeted stair-step increases in plasma levels of lidocaine of 1, 2, and 3 [mu]g/ml. At baseline and at each plasma level, spontaneous and evoked pain scores and neurosensory testing within the painful area were measured. The neurosensory testing consisted of thermal thresholds, tactile thresholds and the area of allodynia to punctate, and stroking and thermal stimuli.

Results: Intravenous lidocaine and diphenhydramine had no significant effect on the cool, warm, or cold pain thresholds. However, lidocaine caused a significant elevation of the hot pain thresholds in the painful area. Intravenous lidocaine caused a significantly decreased response to stroking and cool stimuli in the allodynic area. There was also a significant decrease in pain scores to cool stimuli at all plasma levels and the spontaneous pain at the highest plasma level.     

Underlying Synovial Sarcoma in a Patient with a History of Complex Regional Pain Syndrome: A Case Report

Synovial sarcoma, although commonly found in the lower extremities, is considered a rare neoplasm. One of the distinguishing features of a synovial sarcoma is its initial benign features that can later turn into a more aggressive lesion. Because of the subtle early features, synovial sarcoma can be mistaken for other pathologic entities that present with clinical signs of erythema, warmth, edema, and pain. We present a patient who was originally diagnosed with complex regional pain syndrome. That diagnosis and subsequent treatment of complex regional pain syndrome likely delayed the appropriate evaluation, which led to a 9-month lag in the proper diagnosis. After magnetic resonance imaging and biopsy were performed, synovial sarcoma was diagnosed. The patient was referred to an orthopedic oncologist, who performed a transtibial amputation and chemotherapy. Although rare, neoplasm should always be considered in the differential diagnosis of a clinical presentation of a painful erythematous and edematous mass.     

German translation and external validation of the Radboud Skills Questionnaire in patients suffering from Complex Regional Pain Syndrome 1

Background  

Patients suffering from Complex Regional Pain Syndrome commonly complain of substantial limitations in their activities of daily living. The Radboud Skills Questionnaire measures alterations in the level of disability of patients with Complex Regional Pain Syndrome, but this instrument is currently not available in German. The goals of our study were to translate the Dutch Radboud Skills Questionnaire into German and to assess its external criterion validity with the German version of the Disabilities of the Arm, Shoulder and Hand Questionnaire.     

Regulation of peripheral blood flow in Complex Regional Pain Syndrome: clinical implication for symptomatic relief and pain management

Background  

During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS.     

Effect of Perioperative Vitamin C on the Incidence of Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis

Complex regional pain syndrome type 1 (CRPS-I) is a complex complication that occurs after limb extremity surgeries. Controversy exists regarding the effectiveness of vitamin C in reducing that condition. Therefore, we conducted this systematic review and meta-analysis to assess the role of vitamin C on CRPS-I and functional outcomes after distal radius, wrist, foot, and ankle surgeries. We searched Medline (via PubMed), Embase, the Cochrane Library, Clinicaltrial.gov, and Google Scholar for relevant studies comparing perioperative vitamin C versus placebo after distal radius, wrist, foot, and ankle surgeries from infinity to May 2021. Continuous data such as functional outcomes and pain scores were pooled as mean differences, while dichotomous variables such as the incidence of complex regional pain syndrome and complications were pooled as odds ratios, with 95% confidence interval, using R software (meta package, version 4.9-0) for Windows. Eight studies were included. The timeframe for vitamin C administration in each study ranged from 42 to 50 days postinjury and/or surgical fixation. The effect size showed that vitamin C was associated with a decreased rate of CRPS-1 than placebo (odds ratio 0.33, 95% confidence interval [0.17, 0.63]). No significant difference was found between vitamin C and placebo in terms of complications (odds ratio 1.90, 95% confidence interval [0.99, 3.65]), functional outcomes (mean difference 6.37, 95% confidence interval [-1.40, 14.15]), and pain scores (mean difference -0.14, 95% confidence interval [-1.07, 0.79]). Overall, vitamin C was associated with a decreased rate of CRPS-I than placebo, while no significant difference was found regarding complications, functional outcomes, and pain scores. These results hold true when stratifying fracture type (distal radius, ankle, and foot surgeries) and vitamin C dose (500 mg or 1 g).     

Effect of tadalafil on blood flow,pain, and function in chronic cold Complex Regional Pain Syndrome: a randomized controlled trial

Background  

This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity.