Current Understandings on Complex Regional Pain Syndrome

10. Complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a clinical disorder that can develop following surgery or trauma. Based on the most prominent underlying pathophysiological mechanisms, CRPS can be classified into different subtypes, namely inflammatory, nociplastic/neuropathic, vasomotor, and motor. Depending on the subtype, personalized treatment can be applied. If conservative treatments are insufficient or ineffective, more invasive treatments may be recommended. This article provides an overview of the most recent insights into CRPS and discusses the most common invasive treatments.

METHODS

The literature regarding interventional treatments for CRPS has been systematically reviewed and summarized.

RESULTS

Bisphosphonates are effective in treating the inflammatory subtype, while ketamine can provide pain relief for the nociplastic/neuropathic subtype. Sympathetic blocks are effective in addressing vasomotor disturbances. For patients with refractory symptoms, neurostimulation is a viable option due to its multimechanistic properties for all subtypes. End-of-line motor disturbances may benefit from intrathecal baclofen.

CONCLUSIONS

CRPS is a debilitating condition with an unpredictable course. The effectiveness of treatment varies from patient to patient. When conservative approaches prove insufficient, gradual progression to invasive treatments based on the underlying subtype is recommended.

Innovations in Stroke Recovery and Rehabilitation: Poststroke Pain

Pain can be a significant barrier to a stroke survivors' functional recovery and can also lead to a decreased quality of life. Common pain conditions after stroke include headache, musculoskeletal pain, spasticity-related pain, complex regional pain syndrome, and central poststroke pain. This review investigates the evidence of diagnostic and management guidelines for various pain syndromes after stroke and identifies opportunities for future research to advance the field of poststroke pain.

Peripheral Nerve Block to Treat Pain Caused by Daboia palaestinae Envenomation

Snakebite pain can be challenging to control. We describe our experience managing intolerable pain after conventional treatment failed. A 35-year-old man, presented after a viper snakebite, suffering from intolerable pain in the affected extremity. He had no significant past medical history. All attempts to control the pain conventionally were unsuccessful. Treatment with a supraclavicular nerve block resulted in immediate relief. After the block receded, only a dull pain remained, which later disappeared without recurrence. This experience illustrates the need for personalized pain treatment to avoid subsequent complications.

Baseline predictors related to functional outcomes in patients older than sixty years with complex regional pain syndrome type 1 after distal radius fracture treated conservatively: a prospective observational study

PURPOSE

This study aimed to analyze baseline predictors of functional outcomes six weeks and at one year follow-up in patients older than 60 years with complex regional pain syndrome type 1 (CRPS I) after distal radius fracture (DRF).

METHODS

A total of 120 patients with CRPS I after DRF were prospectively recruited. Presumptive relevant factors were collected and analyzed as potential baseline predictors. Additionally, functional outcomes were assessed at the beginning of physiotherapy treatment, at six weeks after finishing physiotherapy treatment, and at one year follow-up. Patient-Rated Wrist Evaluation; Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire; Jamar dynamometer; and visual analog scale (VAS) were assessed.

RESULTS

All participants completed the study. At 6 weeks, the main results showed an association of lower values of grip strength with female sex (p = 0.010), intra-articular DRFs (p = 0.030), longer immobilization time (p = 0.040), lower levels of physical activity (p < 0.001), higher levels of kinesiophobia (p = 0.010), and anxiety (p = 0.020). At 1-year follow-up, the results showed an association of lower values of DASH with higher BMI (p < 0.001) and longer immobilization time (p < 0.001); and higher values of VAS showed an association with older age (p = 0.010), higher BMI (p = 0.010), and lower levels of physical activity (p = 0.040).

CONCLUSION

At six weeks, factors such as BMI, immobilization time, physical activity, and kinesiophobia are associated with lower functional outcomes. Additionally, at one year follow-up, BMI, immobilization time, and physical activity continue to be associated with lower functional outcomes in patients with CRPS I after DRF treated conservatively.

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.

AUTHORS' CONCLUSIONS

Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

Multidisciplinary Management of Complex Regional Pain Syndrome (CRPS) Type 1 in the Hand and Wrist: A Case Report

Complex regional pain syndrome (CRPS) is a rare disorder that presents as a highly variable combination of intense regional pain, autonomic and vasomotor disturbances that are uncharacteristic of the inciting trauma or event. We report a 36-year-old male construction worker who presented to the orthopedic department status post crush injury to his hand, with acutely increasing right-hand pain, swelling, skin/hair changes, and dysfunction. Presentation changed over a course of 2-8 weeks, with CRPS becoming the eventual working diagnosis. Initial diagnoses were not made by occupational med, nor the urgent care, and definitive diagnosis was achieved in the orthopedic hand office via a thorough history and physical exam as well as imaging modalities including X-ray, CT, and MRI. A multidisciplinary approach involving aggressive hand therapy, anti-inflammatory agents, high-dose prednisone, Gabapentin, and over-the-counter vitamins and supplements was used in the treatment of this patient. This patient had a unique progression of his condition with respect to his carpus, demonstrating acute reduction of bone density on plain film. Stiffness ensued. This patient's condition was almost "missed" by the masking of the ulnar ossicle variant (os triangulare), and anatomical snuffbox pain on exam, in the face of initially "normal" X-rays. It is important for providers to recognize the clinical signs of complex regional pain syndrome, especially in the acute phase of crush injury, swelling, skin and hair changes, and stiffness, and to treat patients' symptoms with a variety of treatment options due to the marked variability of this condition. The patient has made a favorable recovery with some residual functional deficits, however, the patient stated that his quality of life has been restored despite his current stiffness.

Intermittent versus continuous esketamine infusions for long-term pain modulation in complex regional pain syndrome: protocol of a randomized controlled non-inferiority study (KetCRPS-2)

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition of an extremity. While achieving pain relief in CRPS is challenging, esketamine infusions can accomplish pain relief for several weeks post-infusion in a subgroup of CRPS patients. Unfortunately, CRPS esketamine protocols are very heterogeneous in advice on dosage, administration and treatment setting. Currently, no trials are available that study differences between intermittent and continuous esketamine infusions for CRPS. With the current situation of bed shortages, it is difficult to admit patients for several consecutive days for inpatient esketamine treatments. In this study, we investigate whether 6 intermittent outpatient esketamine treatments are not inferior to a continuous 6-day inpatient esketamine treatment in establishing pain relief. In addition, several secondary study parameters will be assessed in order to investigate mechanisms responsible for pain relief by esketamine infusions. Furthermore, the cost-effectiveness will be analyzed.

METHODS

In this RCT, the primary objective is to demonstrate that an intermittent esketamine dosing regimen is non-inferior to a continuous esketamine dosing regimen at 3 months follow-up. We will include 60 adult CRPS patients. The inpatient treatment group receives a continuous intravenous esketamine infusion for 6 consecutive days. The outpatient treatment group receives a 6-hour intravenous esketamine infusion every 2 weeks for 3 months. Esketamine dose will be individually tailored and is started at 0.05 mg/kg/h and can be increased to a maximum of 0.2 mg/kg/h. Each patient will be followed for 6 months. The primary study parameter is perceived pain intensity, measured by an 11-point Numerical Rating Scale. Secondary study parameters are conditioned pain modulation, quantitative sensory testing, adverse events, thermography, blood inflammatory parameter, questionnaires about functionality, quality of life and mood and costs per patient.

DISCUSSION

If our study reveals non-inferiority between intermittent and continuous esketamine infusions, these findings can be beneficial to increase the availability and flexibility of esketamine infusions through outpatient treatments. Furthermore, the costs of outpatient esketamine infusions could be lower than inpatient esketamine infusions. In addition, secondary parameters may predict response to esketamine treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT05212571 , date of registration 01-28-2022.

PROTOCOL VERSION

Version 3, February 2022.

Effectiveness of self-management of dry and wet cupping therapy for low back pain: A systematic review and meta-analysis

BACKGROUND

Low back pain (LBP) can significantly affect a person's quality of life. Cupping has been used to treat LBP. However, various cupping methods are typically included in evaluating the efficacy of cupping therapy. Therefore, the objectives of this study were to evaluate the evidence from the literature regarding the effects of dry and wet cupping therapy on LBP in adults. Dry and wet cupping therapy are analyzed categorically in this study.

METHODS

We searched for randomized clinical trials with cupping in LBP published between 2008 and 2022. In dry or wet cupping clinical studies, pain intensity was assessed using the Visual Analogue Scale and present pain intensity, and the quality of life intensity was measured using the Oswestry disability index.

RESULTS

The 656 studies were identified, of which 10 studies for 690 patients with LBP were included in the meta-analysis. There was a significant reduction in the pain intensity score with present pain intensity using wet cupping therapy (P < .01). In addition, both cupping therapy groups displayed significant Oswestry disability index score reduction compared to the control group (both P < .01). The patients with LBP have a substantial reduction by using wet cupping but have not shown a considerable decrease by using dry cupping (P = .19). In addition, only wet cupping therapy groups displayed a significantly improved quality of life compared to the control group. The study had a very high heterogeneity (I2 > 50%). It means there is no standardization in the treatment protocol in randomized clinical trials. In the meta-regression, there was statistically significant evidence that the number of treatment times and intercepts were related (P < .01).

CONCLUSION

The present meta-analysis shows that wet cupping therapy effectively reduces the pain intensity of LBP. Furthermore, both dry wet cupping therapy improved patients with LBP quality of life.

Functional Outcomes After a Physiotherapy Program in Elderly Patients With Complex Regional Pain Syndrome Type I After Distal Radius Fracture: A Prospective Observational Study

BACKGROUND

No published prospective studies have reported the clinical effects of physiotherapy at 1-year follow-up in patients with complex regional pain syndrome type I (CRPS I) after distal radius fracture (DRF). The purpose of this study was to evaluate at 1-year follow-up the functional effects of physiotherapy program in elderly patients with CRPS I after extra-articular DRF.

METHODS

A total of 72 patients with CRPS I after DRF were prospectively recruited. All patients were treated with a 6-week supervised physiotherapy treatment. Three evaluations were performed: at the beginning, at the end of the treatment, and at 1-year follow-up. Wrist function, upper limb function, grip strength, and pain intensity were assessed with the Patient-Rated Wrist Evaluation (PRWE), Disabilities of the Arm, Shoulder, and Hand (DASH), Jamar dynamometer, and Visual Analogue Scale (VAS), respectively.

RESULTS

At 1-year follow-up, the PRWE showed a decrease of 21.6 points (Cohen's d = 2.8; 95% confidence interval [CI] = 18.6-24.6; P < .05); the DASH showed a decrease of 23.8 points (Cohen's d = 2.9; 95% CI = 20.8-26.7; P < .05); grip strength showed an increase of 40.6% (Cohen's d = 5.0; 95% CI = 43.5-37.6; P < .05); and the VAS showed a decrease of 2.6 cm (Cohen's d = 1.9; 95% CI = 2.11-3.16; P < .05).

CONCLUSION

At 1-year follow-up, a physiotherapy program showed clinically and statistically significant results in all functional outcomes in elderly patients with CRPS I after extra-articular DRF.

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

OBJECTIVE

This 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.

METHODS

This 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 χ² 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.

RESULTS

The 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.

CONCLUSIONS

This 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.

Effectiveness of Peripheral Median, Radial, and Ulnar Nerve Block at Wrist along with Intra-Articular Steroid Injection in Shoulder Joint in Management of Complex Regional Pain Syndrome of Upper Limb: 1-Week Follow-Up Study

BACKGROUND

Complex regional pain syndrome (CRPS) of upper limbs is one of the under-recognized painful disabling condition seen in many neurological conditions.

OBJECTIVE

To see the effectiveness of peripheral nerve blocks (PNB) along with intra-articular injection in shoulder joint in the improvement of pain, swelling and range of motion (ROM) of the upper limb in CRPS.

METHODS

It was a single-center, prospective study in male and female patients between 18 and 70 years with CRPS of the upper limb due to any etiology, within one year of illness. Single-dose of the intra-articular shoulder joint injection and peripheral nerve blocks at the wrist with steroid, 2% lignocaine, and sterile water was given. The primary outcome measure was a reduction in pain in the upper limb, assessed with a visual analog scale (VAS). Secondary outcome measures were an improvement in passive ROM of joints and a decrease in swelling of the hand. The significance of the P value was adjudged against an alpha of 0.05.

RESULTS

Thirty-three patients (25 men), with a mean (SD) age of 55.2 (9.4) years, and mean (SD) duration of illness of 101.9 (76.8) days were included. After 1 week, there was a significant improvement (P < 0.05) in the ROM of joints. The decrease in pain scores on VAS [mean difference -5.1 (CI -5.7, -4.5)] and reduction in hand swelling [mean difference -0.9 (CI -1.1, -0.7)] was also significant.

CONCLUSION

Peripheral median, radial, and ulnar nerve block at wrist along with intra-articular steroid injection in the shoulder joint is an effective method of management of CRPS of the upper limb.

From a Symptom-Based to a Mechanism-Based Pharmacotherapeutic Treatment in Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a debilitating painful condition of a distal extremity that can develop after tissue damage. CRPS is thought to be a multimechanism syndrome and ideally the most prominent mechanism(s) should be targeted by drugs in an individually tailored manner. This review gives an overview of the action and evidence of current and future pharmacotherapeutic options for CRPS. The available options are grouped in four categories by their therapeutic actions on the CRPS mechanisms, i.e. inflammation, central sensitisation, vasomotor disturbances and motor disturbances. More knowledge about the underlying mechanisms of CRPS helps to specifically target important CRPS mechanisms. In the future, objective biomarkers could potentially aid in selecting appropriate mechanism-based drugs in order to increase the effectiveness of CRPS treatment. Using this approach, current and future pharmacotherapeutic options for CRPS should be studied in multicentre trials to prove their efficacy. The ultimate goal is to shift the symptom-based selection of therapy into a mechanism-based selection of therapy in CRPS.

Determinants of complex regional pain syndrome type I in patients with scaphoid waist fracture- a multicenter prospective observational study

Background

The aim of this prospective study was to assess the incidence of complex regional pain syndrome type I (CRPS I) in patients with scaphoid waist fracture and to explore associated factors.

Methods

This was a multicenter, prospective observational study. Demographic, imaging indicators and clinical data were collected before the conservative treatment of scaphoid waist fracture patients. The occurrence of CRPS I and pain condition were the main outcomes. To explore the factors associated with CRPS I, multivariate logistic regression model was used.

Results

A total of 493 scaphoid waist fracture participants undergoing conservative treatment were recruited for this study. The incidence of CRPS I was 20% (n = 87). The average time between injury and the onset of CRPS I was 6.7 ± 2.1 weeks. Multivariable logistic regression analysis revealed that female sex (odds ratio (OR): 1.669; 95% confidence interval (CI): 1.189–2.338), diabetes mellitus (OR: 3.206; 95% CI: 2.284–4.492), and severe pain condition before treatment (visual analog scale (VAS) score more than 4 cm) (OR: 27.966; 95% CI: 19.924–39.187) were independently associated with CRPS I.

Conclusions

Patients suffering from scaphoid waist fracture may be at a higher risk of CRPS I, especially in women with diabetes mellitus who report severe pain before treatment. Early screening and regular follow up evaluation are recommended in these patients.

Complex regional pain syndrome type II caused by iatrogenic lateral dorsal cutaneous nerve injury: A case report

RATIONALE

Complex regional pain syndrome (CRPS) is a painful condition classified as type I or II depending on the absence or presence of nerve injury, respectively. Injury to the lateral dorsal cutaneous nerve (LDCN), a branch of the sural nerve, is a rare occurrence observed after a sprain or procedures conducted on the lateral side of the ankle.

PATIENT CONCERNS

A 38-year-old female, who had undergone prolotherapy for a sprain in the lateral side of the left ankle 3 months ago, presented with persistent causalgia and dysesthesia around the injection site.

DIAGNOSIS

An electrodiagnostic study was conducted, which confirmed that the patient had peripheral neuropathy of the left LDCN. Considering the digital infrared thermal imaging and three-phase bone scan findings and the clinical presentation, the condition was diagnosed as CRPS type II due to iatrogenic LDCN injury according to the Budapest diagnostic criteria for CRPS.

INTERVENTIONS

The patient was treated with steroid pulse therapy, physical therapy, and transcutaneous electrical nerve stimulation, as well as nonsteroidal anti-inflammatory drugs, pregabalin, and tricyclic antidepressants.

OUTCOMES

After 1 month of treatment, allodynia of the left foot persisted, but the pain reduced from 6 points to 3 points on the numeric rating scale. Partial recovery of amplitude and conduction velocity was confirmed in the follow-up electrodiagnostic study.

LESSONS

LDCN injury should be considered in patients who complain of persistent lateral ankle and foot paresthesia or pain after sprain or procedures performed on the lateral side of the ankle. Early diagnosis and treatment can lead to a good prognosis when the LDCN injury has progressed to CRPS.

Neural substrates for poststroke complex regional pain syndrome type I: a retrospective case-control study using voxel-based lesion symptom mapping analysis

Poststroke complex regional pain syndrome (CRPS) is characterized by swelling, pain, and changes in the skin that appear on the affected wrist and hand. In this retrospective study, we analyzed the relationship between poststroke CRPS and the location of stroke lesion. From all patients admitted to our hospital from 2009 to 2019, we recruited 80 patients affected by their first unilateral stroke who met the inclusion/exclusion criteria. Thirty-eight patients diagnosed with CRPS after stroke were assigned to the experimental group according to the "Budapest criteria" adopted by the International Association for the Study of Pain, and 42 patients without CRPS were included as controls. Regions of interest were manually drawn on T1-weighted magnetic resonance images, and data were normalized to a standard brain template. In the poststroke CRPS group, the relationship between the location of brain lesion and pain severity was analyzed using Freedman-Lane multivariable regression adjusting for Medication Quantification Scale rating, which was the only parameter to show a statistically significant correlation with pain intensity. A threshold of P < 0.01 was considered statistically significant for all voxel-based lesion symptom mapping tests, corrected for multiple comparisons with 5000 permutations. Analyses using voxel-wise subtraction and Liebermeister statistics indicated that the corticospinal tract (CST) was associated with the development of poststroke CRPS. Statistically significant correlations were found between pain intensity and the CST and the adjacent lentiform nucleus. Our results suggest that the CST may be a relevant neural structure for development of poststroke CRPS and the intensity of pain caused by the syndrome.

Effects of Tai Chi and running on blood oxygen saturation: a pilot study

OBJECTIVES

Large drops in blood oxygen saturation (SpO2) to levels as low as 84% was observed following Tai Chi practice, during a study on the effects of Tai Chi on SpO2. The objectives of the current pilot study were to determine if this was a statistically significant drop, and how SpO2 levels compared to an aerobic activity such as running, in pre, concurrent, and post measurements.

METHODS

Repeated measures of blood oxygen saturation (SpO2) were taken of a 50-year-old male before, during and for 1 min after TC and running.

RESULTS

Measurements of SpO2 before, during, and after TC resulted in a statistically significant increase in SpO2 during TC (p=1.69e-06), and a statistically significant (p=1.71e-06) brief momentary drop from resting levels, as low as 87% SpO2. Running showed no significant change in pre and post levels, with a significant change and decrease in SpO2 during running (p=1.1e-08), suggesting increased oxygen use by the large muscle groups during exercise. SpO2 returned to normal resting levels following running with no post drop. Results suggest a higher rate of oxygen metabolism during TC, with a potential effect on hypoxic (oxygen deficient) areas of the body.

CONCLUSIONS

Findings suggest direct and unique effects on enhanced blood oxygen saturation and oxygen metabolism, which may underlie benefits for conditions complicated by hypoxia, including cardiopulmonary disease, immunity, chronic pain, and arthritis.

ICF-based multidisciplinary rehabilitation program for complex regional pain syndrome of the hand: efficacy, long-term outcomes, and impact of therapy duration

Background

Complex regional pain syndrome (CRPS) is a rare but feared complication in hand surgery. Although multimodal therapy concepts are recommended, there is only low evidence on efficacy of such approaches. Furthermore, recommendations regarding therapy duration are lacking. Aim of this study was to validate the efficacy of an International Classification of Functioning, Disability and Health (ICF)-based multidisciplinary rehabilitation concept for treatment of CRPS of the hand and to find correlations between therapy duration and outcome measures.

Methods

Patients with CRPS of the hand after occupational trauma that underwent an ICF-based rehabilitation program between 2010 and 2014 were included in this retrospective study. Besides demographic data, outcomes included pain (VAS), range of motion assessed by fingertip-to-palm-distance (PTPD) and fingernail-to-table-distance (FTTD) as well as strength in grip, 3-point pinch and lateral pinch. All measures were gathered at admission to and discharge from inpatient rehabilitation therapy as well as at follow-up. Statistical analysis included paired t-test, ANOVA and Pearson's correlation analysis.

Results

Eighty-nine patients with a mean age of 45 years were included in this study. Duration of rehabilitation therapy was 53 days on average. All outcomes improved significantly during rehabilitation therapy. Pain decreased from 6.4 to 2.2. PTPD of digit 2 to 5 improved from 2.5, 2.8, 2.6, and 2.3 cm to 1.3, 1.4, 1.2, and 1.1 cm, respectively. FTTD of digit 2 to 5 decreased from 1.5, 1.7, 1.5, and 1.6 cm to 0.6, 0.8, 0.7, and 0.7 cm, respectively. Strength ameliorated from 9.5, 3.7, 2.7 kg to 17.9, 5.6, 5.0 kg in grip, lateral pinch, and 3-point pinch, respectively. Improvement in range of motion significantly correlated with therapy duration. 54% of patients participated at follow-up after a mean of 7.5 months. Outcome measures at follow-up remained stable compared to discharge values without significant differences.

Conclusion

The ICF-based rehabilitation concept is a reliable and durable treatment option for CRPS of the hand. Range of motion improved continuously with therapy duration and thus may serve as an indicator for optimum length of therapy.

Complex Regional Pain Syndrome Following Snakebite: A Putatively Rare Complication of Envenomation and Review of the Literature

Background

Complex regional pain syndrome (CRPS) following snakebite is considered rare. Only four cases have been reported in the world literature. The present case is the first in the United States. We felt the need to report this case to bring attention to health-care providers that CRPS is probably an under-recognized complication of snakebite.

Case Presentation

A 44-year-old right-handed man developed signs and symptoms of complex regional pain syndrome (CRPS) in the left upper extremity following a bite by a cat-eyed snake (genus Leptodeira), a slightly venomous snake that belongs to the Colubridae (colubrids) family. The man did not develop muscle weakness or hematologic complications at that time. However, in subsequent years, he developed sporadic jerking of the upper extremities without alteration in consciousness or electroencephalographic abnormalities. These movements tended to occur during emotional tension and exacerbation of pain, and decreased in frequency when the subject was distracted. This is the fifth case of snakebite-induced CRPS described in the world literature (Nepal, Turkey, Korea, and Norway), the first reported in the United States, and the first induced by a slightly venomous snake.

Conclusion

With closer attention to the presence of indicators of sympathetic nerve dysfunction in association with allodynia, it is probable that cases of persistent pain following snakebite might have been instances of CRPS.

The use of bisphosphonates to meet orthopaedic challenges

The anti-resorptive properties of bisphosphonates have been explored to manage several conditions that traditionally have required a surgical solution. In osteonecrosis, their use is predicated on the principle that bone collapse occurs during the revascularisation phase of the disease. If the associated resorptive activity were modulated, the resultant preserved joint architecture may improve clinical outcome and reduce the need for joint replacement. Pre-clinical and small-scale clinical studies have given non-conclusive support for this principle. Adequately powered clinical trials with relevant long-term endpoints are still required to firmly clarify the clinical efficacy of this treatment. Several clinical studies have shown that bisphosphonates can reduce periprosthetic bone loss and, in some situations, enhance implant fixation in the early period after joint replacement. This may be advantageous in settings where osseointegration is problematic. However, the ultimate goals of their use in joint replacement has been to reduce the incidence of late periprosthetic inflammatory osteolysis, the main cause of prosthesis failure. Population-based observational studies have associated bisphosphonate use with a lower incidence of revision surgery, supported by pre-clinical data. However, clinical trials have, to date, failed to demonstrate any efficacy for the human disease. The timing of bisphosphonate administration for secondary prevention after acute osteoporotic fracture has been subject to extensive investigation, with pre-clinical studies showing increased callus formation but decreased remodelling and no effect on the restoration of mechanical integrity of bone. Meta-analysis of clinical trial data indicates that early administration of bisphosphonate after acute fracture does not adversely affect fracture union, pain or functional outcomes. Finally, bisphosphonates have also been explored as a treatment for complex regional pain syndrome type-I. A recent meta-analysis has shown a beneficial effect on visual analogue scale pain scores, but an increase in mild adverse events.

Post-stroke complex regional pain syndrome and related factors: Experiences from a tertiary rehabilitation center

OBJECTIVE

In this study, it is aimed to determine the risk factors associated with CRPS after stroke and the clinical parameters of the patients and the treatment agents used for CPRS METHOD: 213 hemiplegic patients with CRPS diagnosed in Group 1 and 213 hemiplegic patients without CRPS in group 2 (control group) were included in the study designed retrospectively. Demographic data of the patients, Brunnstrom stage, Modified Ashworth scale, Barthel index were recorded from patients files. Associated risk faktors with CRPS such as Shoulder subluxation, adhesive capsulitis, fracture, deep vein thrombosis, spasticity, neglect, visual field defect, heterotopic ossification, entrapment neuropathies, brachial plexus damage, pressure wound, lower respiratory tract infection (LRTI), urinary tract infection, epilepsy, and depression were questioned. In addition, clinical findings, medical treatments, and physical therapy agents used were recorded.

RESULTS

The average age of the participants was 67.9 ± 10.3 in group 1 and 66.1 ± 9.9 in group 2. According to the multivariate logistic regression analysis, the presence of the duration of hemiplegi, the duration of hospitalization, shoulder subluxation, soft tissue lesion, adhesive capsulitis, spasticity, entrapment neuropathy, brachial plexus ınjury, protein energy malnutrition, LRTI, urinary infection, depression, coronary artery disease were significantly increased the development of CRPS (p<0.05). As a clinical parameter, edema was present in 95.3% of the patients, while trophic change was the lowest in 1.9%. While sensory reeducation was used in all patients in physical therapy, ganglion blockade was the lowest with 0.9% of patients. In medical treatment, the use of oral paracetamol was 28.2%, while the use of gabapentin was the last with 8.9%.

CONCLUSIONS

In our study, the risk factors of CRPS after hemiplegia, which are as important as its treatment, as well as its diagnosis and prevention, are shown.

Highlighting the Role of Biomarkers of Inflammation in the Diagnosis and Management of Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is characterized by continuous pain that is often accompanied by sensory, motor, vasomotor, sudomotor, and trophic disturbances. If left untreated, it can have a significant impact on the quality of life of patients. The diagnosis of CRPS is currently based on a set of relatively subjective clinical criteria: the New International Association for the Study of Pain clinical diagnostic criteria for CRPS. There are still no objective laboratory tests to diagnose CRPS and there is a great need for simple, objective, and easily measurable biomarkers in the diagnosis and management of this disease. In this review, we discuss the role of inflammation in the multi-mechanism pathophysiology of CRPS and highlight the application of potential biomarkers of inflammation in the diagnosis and management of this disease.

Nuclear Medicine for the Orthopedic Foot and Ankle Surgeon

Nuclear medicine has been widely applied as a diagnostic tool for orthopedic foot and ankle pathology. Although its indications have diminished with improvements in and the availability of magnetic resonance imaging, nuclear medicine still has a significant and valuable role. The present article offers a comprehensive and current review of the most common nuclear imaging modalities for the orthopedic foot and ankle surgeon. Methods discussed include bone scintigraphy, gallium citrate scintigraphy, labeled-leukocyte scintigraphy, and single-photon emission computed tomography (SPECT). We review the indications and utility of these techniques as they pertain to specific foot and ankle conditions, including osteomyelitis, stress fractures, talar osteochondral lesions, complex regional pain syndrome, oncology, plantar fasciitis, and the painful total ankle arthroplasty. We conclude with a discussion of our approach to nuclear medicine with illustrative cases. Level of Evidence: Level V, expert opinion.

Mechanism-specific rehabilitation management of complex regional pain syndrome: Proposed recommendations from evidence synthesis

STUDY DESIGN

Narrative review.

INTRODUCTION

There are a variety of treatments with demonstrated effectiveness for the management of complex regional pain syndrome (CRPS). However given the variability in symptom presentation in this population, therapists may be unsure what treatments would be most effective for individual clients.

PURPOSE OF THE STUDY

To present a brief synthesis of the literature and propose a rehabilitation version of a mechanism-specific management algorithm to guide personalized treatment of CRPS.

METHODS

A systematic search of the literature was conducted to identify all randomized controlled trials, systematic reviews, and clinical practice guidelines addressing rehabilitation of CRPS. Results were reviewed independently by 2 reviewers and final selection of articles was reached by consensus, Data was extracted using standardized forms, and a single rater gave quality ratings. Both reviewers then used the extracted data to present a synthesis of the evidence categorized by the proposed mechanisms of effect.

RESULTS

A total of 111 articles were retrieved and reviewed for inclusion; 49 were selected for data extraction. A synthesis of the key recommendations was compiled into a rehabilitation-specific version of the mechanism-based management algorithm proposed by Gierthmühlen et al (2014).

CONCLUSIONS

Consideration of mechanism-appropriate rehabilitation interventions may assist therapists to select the most appropriate and effective treatments from the body of evidence supporting rehabilitation of CRPS.

A case report of wireless peripheral nerve stimulation for complex regional pain syndrome type-I of the upper extremity: 1 year follow up

Background

Complex regional pain syndrome (CRPS) is a chronic disabling painful disorder with limited options to achieve therapeutic relief. CRPS type I which follows trauma, may not show obvious damage to the nervous structures and remains dubious in its pathophysiology and also its response to conservative treatment or interventional pain management is elusive. Spinal cord and dorsal root ganglion stimulation (SCS, DRGS) provide good relief, mainly for causalgia or CRPS I of lower extremities but not very encouraging for upper extremity CRPS I. we reported earlier, a case of CRPS I of right arm treated successfully by wireless peripheral nerve stimulation (WPNS) with short term follow up. Here we present 1-year follow-up of this patient.

Objective

To present the first case of WPNS for CRPS I with a year follow up. The patient had minimally invasive peripheral nerve stimulation (PNS), without implantable pulse generator (IPG) or its accessories.

Case report

This was a case of refractory CRPS I after blunt trauma to the right forearm of a young female. She underwent placement of two Stimwave electrodes (Leads: FR4A-RCV-A0 with tines, Generation 1 and FR4A-RCV-B0 with tines, Generation 1) in her forearm under intraoperative electrophysiological and ultrasound guidance along radial and median nerves. This WPNS required no IPG. At high frequency (HF) stimulation (HF 10 kHz/32 μs, 2.0 mA), patient had shown remarkable relief in pain, allodynia and temperature impairment. At 5 months she started driving without opioid consumption, while allodynia disappeared. At 1 year follow up she was relieved of pain [visual analogue scale (VAS) score of 4 from 7] and Kapanji Index (Score) improved to 7–8. Both hands look similar in color and temperature. She never made unscheduled visits to the clinic or visited emergency room for any complications related to the WPNS.

Conclusions

CRPS I involving upper extremity remain difficult to manage with conventional SCS or DRGS because of equipment related adverse events. Minimally invasive WPNS in this case had shown consistent relief without any complications or side effects related to the wireless technology or the technique at the end of 1 year.

Implications

This is the first case illustration of WPNS for CRPS I, successfully treated and followed up for 1 year.

Diagnosing complex regional pain syndrome using an electronic nose, a pilot study

OBJECTIVE

Complex regional pain syndrome (CRPS) is a complication after surgery or trauma and is characterized by a continuing regional pain in a distal extremity. The pain is disproportionate in severity and duration in relation to the preceding trauma. Currently, the diagnosis is based on the patients' signs and symptoms. There is no objective clinically applicable test available to confirm the diagnosis of CRPS, however this could contribute to a more reliable and valid diagnosis. Since the treatment of CRPS differs from that of other types of pain this could thereby lead to earlier and (more) appropriate treatment and possibly to lower medical costs. The Aeonose™ is a diagnostic test device which detects volatile organic profiles in exhaled air. Exhaled breath analysis using an electronic nose has been successfully applied to differentiate between sick and healthy persons for various indications. This study was a feasibility study in which we investigated whether the Aeonose™ is able to measure a difference in the volatome of CRPS patients compared to the volatome of healthy controls.

DESIGN

Prospective observational study.

SETTING

University Center for Pain Medicine.

SUBJECTS

Adult patients diagnosed with CRPS according to the latest IASP criteria (n = 36) and matched healthy controls (n = 36).

METHODS

Breath profiles were sampled by breathing in and out through the Aeonose™. Data were compressed using a Tucker3-like solution and subsequently used for training an artificial neural network together with the classification 'CRPS: Yes' or 'CRPS: No'. Cross-validation was applied using the leave-10%-out method.

RESULTS

Data of the 72 participants were analyzed, resulting in a sensitivity of 83% (95% CI 67%-93%), specificity of 78% (95% CI 60%-89%), and an overall accuracy of 81%.

CONCLUSIONS

This study suggests that the Aeonose™ can possibly distinguish patients with CRPS from healthy controls based on analysis of their volatome (MEC-2014-149).

A rare cause of type 1 complex regional pain syndrome: Osteoblastoma of the talus

We report a 14-year-old boy who presented with pain in the left foot and ankle for about 9 months. The clinical symptoms of the patient suggested complex regional pain syndrome (CRPS). The radiographs and magnetic resonance imaging studies ravealed a bone tumor in the talus, consistent with an osteoblastoma. The patient underwent operative treatment with curettage and grafting. The complaints of the patient completely resolved by 6 months after surgery, and there was no recurrence at the postoperative 23th month follow-up.

Investigate the Effect of Psychological Factors in Development of Complex Regional Pain Syndrome Type I in Patients with Fracture of the Distal Radius: A Prospective Study

Background: To investigate the role of psychological factors (anxiety and depression) and pain measured on a visual analogue scale (VAS) in the development of complex regional pain syndrome type I (CRPS I) following the distal radius fracture (DRF).

Methods: A consecutive sample of patients (N=60) with a distal radius fracture was measured for signs of CRPS by Budapest criteria weekly till 8 weeks and then another follow-up one year after injury to determine the incidence and predictors of developing CRPS I in a prospective cohort study and also to discover whether there is difference between pain, depression, and anxiety level in the patients with and without CRPS I. The most of the patients were treated by Pin stabilization. The Beck depression inventoryshort form (BDI), State-Trait Anxiety Inventory, and Numerical pain rating scale were used to determine the patients’ psychological features and pain intensity at the base line and 8 weeks after the fracture.

Results: CRPS I developed in 15 (25%) patients after eight weeks and just last in 10 (16.67%) patients after one year. No difference was found between the two groups (CRPS and non-CRPS group) in terms of state (STAI-I) and trait (STAI-II) anxiety, and BDI score. Pain at the base line was the most important risk factor in developing CRPS (odds ratio [OR] =1.52; 95% CI).

Conclusions: After fracturing the distal radius, patients who have high pain intensity have a higher risk of developing CRPS I. To following these patients closely for the development of CRPS I may be advantageous for early preventative and therapeutic interventions.

The Rodent Tibia Fracture Model: A Critical Review and Comparison With the Complex Regional Pain Syndrome Literature

Distal limb fracture is the most common cause of complex regional pain syndrome (CRPS), thus the rodent tibia fracture model (TFM) was developed to study CRPS pathogenesis. This comprehensive review summarizes the published TFM research and compares these experimental results with the CRPS literature. The TFM generated spontaneous and evoked pain behaviors, inflammatory symptoms (edema, warmth), and trophic changes (skin thickening, osteoporosis) resembling symptoms in early CRPS. Neuropeptides, inflammatory cytokines, and nerve growth factor (NGF) have been linked to pain behaviors, inflammation, and trophic changes in the TFM model and proliferating keratinocytes were identified as the primary source of cutaneous cytokines and NGF. Tibia fracture also activated spinal glia and upregulated spinal neuropeptide, cytokine, and NGF expression, and in the brain it changed dendritic architecture. B cell-expressed immunoglobulin M antibodies also contributed to pain behavior, indicating a role for adaptive immunity. These results modeled many findings in early CRPS, but significant differences were also noted.

PERSPECTIVE

Multiple neuroimmune signaling mechanisms contribute to the pain, inflammation, and trophic changes observed in the injured limb of the rodent TFM. This model replicates many of the symptoms, signs, and pathophysiology of early CRPS, but most post-fracture changes resolve within 5 months and may not contribute to perpetuating chronic CRPS.

Sensory modulation dysfunction is associated with Complex Regional Pain Syndrome

OBJECTIVE

Complex Regional Pain Syndrome (CRPS), a chronic pain condition, develops mainly after limb trauma and severely inhibits function. While early diagnosis is essential, factors for CRPS onset are elusive. Therefore, identifying those at risk is crucial. Sensory modulation dysfunction (SMD), affects the capacity to regulate responses to sensory input in a graded and adaptive manner and was found associated with hyperalgesia in otherwise healthy individuals, suggestive of altered pain processing.

AIM

To test SMD as a potential risk factor for CRPS.

METHODS

In this cross-sectional study, forty-four individuals with CRPS (29.9±11 years, 27 men) and 204 healthy controls (27.4±3.7 years, 105 men) completed the Sensory Responsiveness Questionnaire-Intensity Scale (SRQ-IS). A physician conducted the CRPS Severity Score (CSS), testing individuals with CRPS.

RESULTS

Thirty-four percent of the individuals with CRPS and twelve percent of the healthy individuals were identified to have SMD (χ2 (1) = 11.95; p<0.001). Logistic regression modeling revealed that the risk of CRPS is 2.68 and 8.21 times higher in individuals with sensory over- and sensory under-responsiveness, respectively, compared to non-SMD individuals (p = 0.03 and p = 0.01, respectively).

CONCLUSIONS

SMD, particularly sensory under-responsiveness, might serve as a potential risk factor for CRPS and therefore screening for SMD is recommended. This study provides the risk index probability clinical tool a simple evaluation to be applied by clinicians in order to identify those at risk for CRPS immediately after injury. Further research is needed.

Graded motor imagery for women at risk for developing type I CRPS following closed treatment of distal radius fractures: a randomized comparative effectiveness trial protocol

BACKGROUND

Distal radius fractures (DRF) account for nearly one-fifth of all fractures in older adults, and women experience them 5× as often as men. Most DRF occur with low impact injuries to the wrist with an outstretched hand, and are often managed via closed treatment and cast immobilization. Women sustaining a DRF are at risk for upper limb immobility, sensorimotor changes, edema and type I complex regional pain syndrome (CRPS). Since CRPS onset is likely influenced by alterations in the brain's somatosensory region, a rehabilitation intervention, Graded Motor Imagery (GMI), aims to restore cortical representation, including sensory and motor function, of the affected limb. To date, there are no studies on the use of GMI in reducing risk of or preventing the onset of type I CRPS in women with DRF treated with cast immobilization. Due to a higher likelihood of women with this injury developing type I CRPS, it is important to early intervention is needed.

METHODS/DESIGN

This article describes a six-week randomized comparative effectiveness trial, where the outcomes of a modified GMI program (mGMI) + standard of care (SOC) group (n = 33) are compared to a SOC only control group (n = 33). Immediately following cast immobilization, both groups participate in four 1-h clinic-based sessions, and a home program for 10 min three times daily until cast removal. Blinded assessments occur within 1 week of cast immobilization (baseline), at three weeks post cast immbolization, cast removal, and at three months post cast removal. The primary outcomes are patient reported wrist/hand function and symptomology on the Patient Rated Wristand Hand Evaluation, McGill Pain Questionnaire, and Budapest CRPS Criteria. The secondary outcomes are grip strength, active range of motion as per goniometry, circumferential edema measurements, and joint position sense.

DISCUSSION

This study will investigate the early effects of mGMI + SOC hand therapy compared to SOC alone. We intend to investigate whether an intervention, specifically mGMI, used to treat preexisiting pain and motor dysfunction might also be used to mitigate these problems prior to their onset. If positive effects are observed, mGMI + SOC may be considered for incorporation into early rehabilitation program.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov with identifier NCT02957240 (Approval date: April 20, 2017).

Wireless peripheral nerve stimulation for complex regional pain syndrome type I of the upper extremity: a case illustration introducing a novel technology

Background

Complex regional pain syndrome (CRPS) is a debilitating painful disorder, cryptic in its pathophysiology and refractory condition with limited therapeutic options. Type I CRPS with its variable relationship to trauma has often no discernible fractures or nerve injuries and remains enigmatic in its response to conservative treatment as well as the other limited interventional therapies. Neuromodulation in the form of spinal cord and dorsal root ganglion stimulation (SCS, DRGS) has shown encouraging results, especially of causalgia or CRPS I of lower extremities. Upper extremity CRPS I is far more difficult.

Objective

To report a case of upper extremity CRPS I treated by wireless peripheral nerve stimulation (WPNS) for its unique features and minimally invasive technique. The system does not involve implantation of battery or its connections.

Case report

A 47 year old female patient presented with refractory CRPS I following a blunt trauma to her right forearm. As interventional treatment in the form of local anesthetics (Anesthesia of peripheral branches of radial nerve) and combined infusions of ketamine/lidocaine failed to provide any significant relief she opted for WPNS treatment. Based on the topographic distribution, two electrodes (Stimwave Leads: FR4A-RCV-A0 with tines, Generation 1 and FR4A-RCV-B0 with tines, Generation 1), were placed along the course of radial and median nerves under ultrasonography monitoring and guided by intraoperative stimulation. This procedure did not involve implantation of extension cables or the power source. At a frequency of 60 Hz and 300 μs the stimulation induced paresthesia along the distribution of the nerves. Therapeutic relief was observed with high frequency (HF) stimulation (HF 10 kHz/32 μs, 2.0 mA) reducing her pain from a visual analogue scale (VAS) score of 7–4 postoperatively. Three HF stimulations programs were provided at the time of discharge, as she improved in her sensory impairment to touch, pressure and temperature at her first follow up visit. At 5-months she was able to drive, did not require opioids and allodynia disappeared.

Conclusions

In a case with difficult CRPS I involving upper extremity, a minimally invasive WPNS of radial and median nerves provided good symptomatic relief. The procedure was tolerated well and both electrodes remained in place without any adverse events.

Implications

In view of the very limited options currently available to manage CRPS, WPNS can be a promising therapeutic modality.

Update on the effects of graded motor imagery and mirror therapy on complex regional pain syndrome type 1: A systematic review

Graded motor imagery (GMI) and mirror therapy (MT) is thought to improve pain in patients with complex regional pain syndrome (CRPS) types 1 and 2. However, the evidence is limited and analysis are not independent between types of CRPS. The purpose of this review was to analyze the effects of GMI and MT on pain in independent groups of patients with CRPS types 1 and 2. Searches for literature published between 1990 and 2016 were conducted in databases. Randomized controlled trials that compared GMI or MT with other treatments for CRPS types 1 and 2 were included. Six articles met the inclusion criteria and were classified from moderate to high quality. The total sample was composed of 171 participants with CRPS type 1. Three studies presented GMI with 3 components and three studies only used the MT. The studies were heterogeneous in terms of sample size and the disorders that triggered CRPS type 1. There were no trials that included participants with CRPS type 2. GMI and MT can improve pain in patients with CRPS type 1; however, there is not sufficient evidence to recommend these therapies over other treatments given the small size and heterogeneity of the studied population.

Current practice in the rehabilitation of complex regional pain syndrome: a survey of practitioners

INTRODUCTION

International clinical guidelines for Complex Regional Pain Syndrome recommend a wide range and variation of rehabilitation therapies as the core treatment. It is likely that most therapists employ a range of approaches when managing people with Complex Regional Pain Syndrome but a recent Cochrane review identified little evidence relating to the effectiveness of multi-modal rehabilitation. There is need for up to date trials of rehabilitation for Complex Regional Pain Syndrome, but in order to develop a clear model of best practice that can be rigorously evaluated we need to understand current practice.

METHOD

An electronic survey was disseminated internationally to clinicians involved in the rehabilitation of individuals with Complex Regional Pain Syndrome. The survey aimed to establish which criteria are used for diagnosis and which modalities clinicians use to treat Complex Regional Pain Syndrome and which they consider ineffective or harmful.

RESULTS

132 valid responses were received. A third of participants did not use any established criteria to diagnose Complex Regional Pain Syndrome. Current practice commonly included patient education, encouragement of self-management, and physical exercises. Cortically directed treatments such as graded motor imagery and psychological approaches were often incorporated into treatment whereas pain provocative therapies, splinting, contrast bathing, and cold and heat therapy were rarely used in the acute or chronic phase of Complex Regional Pain Syndrome.

CONCLUSION

A broad range of modalities are currently used in Complex Regional Pain Syndrome rehabilitation. Practice appears to be characterized by educational and exercise based interventions delivered in a pain-contingent manner which largely echoes recommendations in international clinical guidelines. Implications for Rehabilitation: Patients with Complex Regional Pain Syndrome suffer from a painful and disabling condition for which we still do not know the best treatment options. From our survey sample most clinicians use treatments recommended in the international guidelines. A large proportion of clinicians from our survey sample are not using internationally recognized diagnostic criteria and we therefore recommend that clinicians become familiar with these criteria and use them for all suspected Complex Regional Pain Syndrome cases.

Risk Factors for Post-treatment Complex Regional Pain Syndrome (CRPS): An Analysis of 647 Cases of CRPS from the Danish Patient Compensation Association

OBJECTIVES

Complex regional pain syndrome is a challenging condition that includes a broad spectrum of sensory, autonomic, and motor features predominantly in extremities recovering from a trauma. Few large-scale studies have addressed occurrence of and factors associated with complex regional pain syndrome (CRPS) following orthopedic treatment. The present study aimed to identify factors associated with post-treatment development of CRPS.

METHODS

Using the Danish Patient Compensation Association's database, we identified 647 patients claiming post-treatment CRPS between 1992 and 2015. Age, gender, initial diagnosis, treatment, and amount of compensation were extracted. Multivariate logistic regressions were performed to identify variables associated with approval of the claim. For carpal tunnel syndrome (CTS) patients, we registered whether symptoms were bilateral or unilateral and if neurophysiology prior to treatment was pathologic.

RESULTS

The following ratios were found: women:men was 4:1, primary diagnosis to the upper limb:lower limb was 2.5:1, and surgical:nonsurgical treatment was 3:1. Mean age was 47.5 ± 13.7 years, and no intergender difference was detected. Antebrachial fracture (23%) and CTS (9%) were the most common primary conditions. Surgical treatment was associated with approval of the claim (odds ratio 3.5, 95% confidence interval 2.3 to 5.3; P < 0.001). Half of CTS patients had normal neurophysiology prior to surgery; among patients with unilateral symptoms, 71.4% had normal neurophysiology.

CONCLUSIONS

Female gender, surgical treatment, and treatment to the upper limb were risk factors. Elective surgery accounted for a large number of post-treatment CRPS patients. In CTS patients developing CRPS, normal neurophysiological examination findings were common, and it could be suspected that these patients were suffering from an pre-clinical stage of CRPS, not CTS.

Elevated Plasma Levels of sIL-2R in Complex Regional Pain Syndrome: A Pathogenic Role for T-Lymphocytes?

The immune system has long been thought to be involved in the pathophysiology of complex regional pain syndrome (CRPS). However, not much is known about the role of the immune system and specifically T-cells in the onset and maintenance of this disease. In this study, we aimed to evaluate T-cell activity in CRPS by comparing blood soluble interleukin-2 receptor (sIL-2R) levels between CRPS patients and healthy controls. CRPS patients had statistically significant elevated levels of sIL-2R as compared to healthy controls (median sIL-2R levels: 4151 pg/ml (Q3 − Q1 = 5731 pg/ml − 3546 pg/ml) versus 1907 pg/ml (Q3 − Q1: 2206 pg/ml − 1374 pg/ml), p < 0.001, resp.). Furthermore, sIL-2R level seems to be a good discriminator between CRPS patients and healthy controls with a high sensitivity (90%) and specificity (89.5%). Our finding indicates increased T-cell activity in patients with CRPS. This finding is of considerable relevance as it could point towards a T-cell-mediated inflammatory process in this disease. This could pave the way for new anti-inflammatory therapies in the treatment of CRPS. Furthermore, sIL-2R could be a promising new marker for determining inflammatory disease activity in CRPS.

Complex regional pain syndrome: medical and legal ramifications of clinical variability and experience and perspective of a practicing clinician

Objective

The aim of this study was to demonstrate the ramifications of clinical variability of complex regional pain syndrome (CRPS) and how they can affect the various aspects of this condition, favorably or unfavorably, for both patients and participating medical and legal professionals.

Methods

Twelve patients diagnosed with CRPS at different times in the past 25 years were followed up, and their signs and symptoms were reviewed for variability. None had preexisting or ongoing medical disorders and prior injury to the peripheral nerves or musculoskeletal tissues. None had been involved in litigation. Physical traumas that triggered CRPS were job-related, vehicular accidents, and personal injuries. The presence of vasomotor symptoms (eg, swelling, skin discoloration, and temperature changes) and allodynia in the affected extremity was the basis for clinical diagnosis in all the patients. The need for imaging studies was precluded in some patients owing to the presence of vasomotor symptoms, which either fluctuated or were steady. Seven of the patients had type 1 CRPS, and five patients had type 2 CRPS.

Results

Most patients encountered delay in diagnosis and treatment and legal obstacles owing to the lack of “typical” objective signs of CRPS. The patients’ symptoms fluctuated at different times of the day. Eight patients experienced spread of vasomotor symptoms and varying degree of allodynia in the opposite extremity. One patient, who developed signs and symptoms of rheumatoid arthritis, 2 months after the injury, continued to have CRPS symptoms in the injured hand. Treatment modalities administered in all the patients were essentially ineffective. All the patients, except one, were unable to return to their original line of work, and their symptoms persisted regardless of the outcome of their legal claims.

Conclusion

It is likely that patients who continue to complain of pain and vasomotor symptoms followed by a physical injury have CRPS. The complex interaction between the peripheral, autonomic, and central nervous system in this condition makes it challenging to diagnose, treat, and prognosticate.

[Complex regional pain syndrome: A review]

BACKGROUND

Complex regional pain syndrome is characterized by spontaneous or induced pain disproportionate in relation to the initial event and is accompanied by a variety of regional and motor disturbances, leading to a variety of clinical presentations. It is often associated with surgery and minor trauma.

PATHOPHYSIOLOGY

Three mechanisms are postulated: changes secondary to post traumatic inflammation, peripheral vasomotor dysfunction and structural and functional changes of the central nervous system as a result of maladaptation.

DIAGNOSIS

made based on the criteria of Budapest. The patient must have one symptom and sign of each criterion at diagnosis: Continuing pain, disproportionate to any inciting event. A sensory, vasomotor, oedema and motor/trophic change sign and symptoms that are not explained by another diagnosis or cause.

TREATMENT

Multimodal treatment is suggested. There is no gold standard. In early stage NSAIDs or steroids can be used. Drugs used for neuropathic pain treatment have been suggested, but there is not enough evidence for any of these. There is low evidence that bisphosphonates, calcitonin, ketamine and mirror therapy are effective compared to placebo. Interventional treatment should be stepped from epidural block, neurostimulation, intrathecal pump to experimental therapies in case of intractable pain.

DISCUSSION

Although complex regional pain syndrome has been a recognized entity for over 100 years, no clear evidence exists for first-line treatments; however, new technologies that are applicable in complex regional pain syndrome treatment have been developed.

Adult Complex Regional Pain Syndrome Type I: A Narrative Review

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

LEVEL OF EVIDENCE

Not applicable.

A rare complication of total knee arthroplasty: Type l complex regional pain syndrome of the foot and ankle

Complex regional pain syndrome (CRPS) is a painful and disabling disorder that usually affects the extremities. This complication may affect the knee joint after total knee arthroplasty (TKA). We report a unique case of CRPS of the foot and ankle, which was an unusual involvement site for CRPS after TKA.

Increased prevalence of posttraumatic stress disorder in CRPS

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

SIGNIFICANCE

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

Local anaesthetic sympathetic blockade for complex regional pain syndrome

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews, 2005, Issue 4 (and last updated in the Cochrane Database of Systematic Reviews, 2013 issue 8), on local anaesthetic blockade (LASB) of the sympathetic chain to treat people with complex regional pain syndrome (CRPS).

OBJECTIVES

To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure.

SEARCH METHODS

For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 9), MEDLINE (Ovid), EMBASE (Ovid), LILACS (Birme), conference abstracts of the World Congresses of the International Association for the Study of Pain, and various clinical trial registers up to September 2015. We also searched bibliographies from retrieved articles for additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS compared to placebo, no treatment, or alternative treatments.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The outcomes of interest were reduction in pain intensity, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table.

MAIN RESULTS

We included an additional four studies (N = 154) in this update. For this update, we excluded studies that did not follow up patients for more than 48 hours. As a result, we excluded four studies from the previous review in this update. Overall we included 12 studies (N = 461), all of which we judged to be at high or unclear risk of bias. Overall, the quality of evidence was low to very low, downgraded due to limitations, inconsistency, imprecision, indirectness, or a combination of these.Two small studies compared LASB to placebo/sham (N = 32). They did not demonstrate significant short-term benefit for LASB for pain intensity (moderate quality evidence).One small study (N = 36) at high risk of bias compared thoracic sympathetic block with corticosteroid and local anaesthetic versus injection of the same agents into the subcutaneous space, reporting statistically significant and clinically important differences in pain intensity at one-year follow-up but not at short term follow-up (very low quality evidence).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB (very low quality evidence).Eight small randomised studies compared sympathetic blockade to various other active interventions. Most studies found no difference in pain outcomes between sympathetic block versus other active treatments (low to very low quality evidence).One small study compared ultrasound-guided LASB with non-guided LASB and found no clinically important difference in pain outcomes (very low quality evidence).Six studies reported adverse events, all with minor effects reported.

AUTHORS' CONCLUSIONS

This update's results are similar to the previous versions of this systematic review, and the main conclusions are unchanged. There remains a scarcity of published evidence and a lack of high quality evidence to support or refute the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence, it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention, but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.

Intravenous Therapies for Complex Regional Pain Syndrome: A Systematic Review

Complex regional pain syndrome (CRPS) remains a challenging clinical pain condition. Multidisciplinary approaches have been advocated for managing CRPS. Compared with spinal cord stimulation and intrathecal targeted therapy, IV treatments are less invasive and less costly. We aimed to systemically review the literature on IV therapies and determine the level of evidence to guide the management of CRPS. We searched PubMed, Embase, Scopus, and the Cochrane databases for articles published on IV therapies of CRPS up through February 2015. The search yielded 299 articles, of which 101 were deemed relevant by reading the titles and 63 by reading abstracts. All these 63 articles were retrieved for analysis and discussion. We evaluated the relevant studies and provided recommendations according to the level of evidence. We conclude that there is evidence to support the use of IV bisphosphonates, immunoglobulin, ketamine, or lidocaine as valuable interventions in selected patients with CRPS. However, high-quality studies are required to further evaluate the safety, efficacy, and cost-effectiveness of IV therapies for CRPS.

Building the evidence for CRPS research from a lived experience perspective

Background and aims

Pain is known to be a subjective experience yet the majority of pain related research does not address the lived experience of the condition. Difficult to diagnose, Complex Regional Pain Syndrome (CRPS) is often poorly managed. The aim of this paper was to identify and synthesise the currently available literature on experiences of living with chronic pain in order to understand where and how CRPS research may be best situated in the future.

Methods

A narrative review was performed and ProQuest, EBSCO, Informit, Scopus/Science Direct and Web of Science, Medline, CINHAL and Google Scholar were searched in order to identify the literature from 1998 until 2015. 301 papers were identified of which 197 described the lived experience of chronic pain conditions. 12 papers were examined closely to determine the experience of living with CRPS or a similar chronic pain condition that does not have a definite pain origin such as cancer or endometriosis.

Results

Known understandings of pain were identified and a model was developed depicting the lived experience of chronic pain starting with loss of the former healthy, pain free self and culminating in acceptance of the condition. Major themes identified were disbelief/invisibility of pain, loss, coping with a non-compliant/constant painful body, self-management and alleviating pain/treatment. The review also found that there is no peer-reviewed published literature on the lived experience of CRPS.

Conclusions

Little is known about the lived experience of CRPS. There appears to be a clear indication that research needs to be conducted into CRPS from a lived experience perspective in order to provide information to patients, the general public, health practitioners and policy makers of previously unknown characteristics of this condition which may improve health outcomes for this patient cohort.

It has been identified that patients and their families should be active participants in education of health practitioners and in providing information to inform the development of National Pain Strategies currently being devised throughout the world.

Implications

Research into the lived experience of chronic pain conditions, and CRPS in particular, can help to provide information to enhance understanding enabling national pain strategies and future treatment guidelines strategies to be devised appropriately.

Complex regional pain syndrome type I: a comprehensive review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Inflammation in cold complex regional pain syndrome

BACKGROUND

In patients with complex regional pain syndrome (CRPS), the temperature of the affected side often differs from that of the contralateral side. In the acute phase, the affected side is usually warmer than the contralateral side, the so-called 'warm' CRPS. This thermal asymmetry can develop into a colder affected side, the so-called 'cold' CRPS. In contrast to cold CRPS, in warm CRPS, inflammation is generally assumed to be present. However, there are reports of cold CRPS patients, successfully treated with vasodilatation therapy, who subsequently displayed warm CRPS. It seems that inflammation could be 'hidden' behind vasomotor disturbance. This study was designed to test this hypothesis.

METHODS

A retrospective analysis was made of patients in our CRPS database. We defined three types of CRPS: cold CRPS, neither cold nor warm (intermediate) CRPS, and warm CRPS. Of these patients, the difference between the level of the pro-inflammatory cytokines interleukin (IL)-6 (Δ IL-6) and tumor necrosis factor (TNF)-α (Δ TNF-α) in the affected extremity and that in the contralateral extremity was determined.

RESULTS

The bilateral difference of the level of these cytokines did not differ among patients with cold CRPS, intermediate CRPS, or those with warm CRPS.

CONCLUSION

Inflammation may be involved in cold CRPS.