Bisphosphonate therapy of reflex sympathetic dystrophy syndrome

Efficacy and Safety of Pharmacological Treatment in Patients with Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis

Complex regional pain syndrome (CRPS) is a disabling condition that usually affects the extremities after trauma or surgery. At present, there is no FDA-approved pharmacological treatment for patients with CRPS. We performed this systematic review and meta-analysis to evaluate the efficacy and safety of pharmacological therapies and determine the best strategy for CRPS. We searched the databases, including PubMed, Embase, Cochrane, Web of Science, Scopus, and ClinicalTrials.gov, for published eligible randomized controlled trials (RCTs) comparing pharmacological treatment with placebo in CRPS patients. Target patients were diagnosed with CRPS according to Budapest Criteria in 2012 or the 1994 consensus-based IASP CRPS criteria. Finally, 23 RCTs comprising 1029 patients were included. We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to rate certainty (confidence in evidence and quality of evidence). Direct meta-analysis showed that using bisphosphonates (BPs) (mean difference [MD] -2.21, 95% CI -4.36--0.06, p = 0.04, moderate certainty) or ketamine (mean difference [MD] -0.78, 95% CI -1.51--0.05, p = 0.04, low certainty) could provide long-term (beyond one month) pain relief. However, there was no statistically significant difference in the efficacy of short-term pain relief. Ketamine (rank p = 0.55) and BPs (rank p = 0.61) appeared to be the best strategies for CRPS pain relief. Additionally, BPs (risk ratio [RR] = 1.86, 95% CI 1.34-2.57, p < 0.01, moderate certainty) and ketamine (risk ratio [RR] = 3.45, 95% CI 1.79-6.65, p < 0.01, moderate certainty) caused more adverse events, which were mild, and no special intervention was required. In summary, among pharmacological interventions, ketamine and bisphosphonate injection seemed to be the best treatment for CRPS without severe adverse events.

Pharmacologic Treatments in Upper Extremity Complex Regional Pain Syndrome: A Review and Analysis of Quality of Evidence

BACKGROUND

The purpose of this study was to assess the quality of evidence informing on common pharmacologic modalities used in upper extremity complex regional pain syndrome (CRPS).

METHODS

A literature search was performed for primary prospective trials that reported on the pharmacologic treatment of CRPS type I and II specific to the upper extremity. Thirty-one trials were included and evaluated by 2 independent reviewers according to the Oxford Levels of Evidence (LOE), modified Coleman Methodology Score, and the revised Consolidated Standards of Reporting Trials (CONSORT) score. Cohen's kappa coefficient was calculated to measure interrater reliability.

RESULTS

Twenty-two Oxford LOE I and 9 level II trials met the inclusion criteria. Overall, there was high interrater reliability in the Oxford LOE (100% agreement), modified Coleman Methodology Score (87% agreement), and CONSORT score (94% agreement). The pharmacologic interventions with the highest quality of evidence supporting use in treatment of upper extremity CRPS were bisphosphonates and ketamine. Interventions that lack high-quality evidence are tricyclic antidepressants (TCAs) and topical dimethyl sulfoxide (DMSO). Pharmacologic agents that remain inconclusive are calcitonin, gabapentin, mycophenolate, probiotics, steroids, nonsteroidal anti-inflammatory drugs, vitamin C, and N-acetylcysteine. Agents with limited benefit are mannitol, isosorbide dinitrate, guanethidine, and morphine.

CONCLUSIONS

Based on the evidence evaluated in this study, bisphosphonates should be considered as a first-line medication in the treatment of CRPS. In patients presenting with chronic or refractory CRPS, strong consideration should be given for the use of ketamine. Adjunct treatment in the acute setting should include TCAs and/or topical DMSO.

Complex Regional Pain Syndrome (CRPS) and the Value of Early Detection

PURPOSE OF REVIEW

The goal of this narrative review is to describe the current understanding of the pathology of Complex Regional Pain Syndrome (CRPS), as well as diagnostic standards and therapeutic options. We will then make the case for early recognition and management.

RECENT FINDINGS

CRPS remains an enigmatic pain syndrome, comprising several subtypes. Recent recommendations clarify diagnostic ambiguities and emphasize the importance of standardized assessment and therapy. Awareness of CRPS should be raised to promote prevention, early detection, and rapid escalation of therapy in refractory cases. Comorbidities and health costs (i.e., the socioeconomic impact) must also be addressed early to prevent negative consequences for patients.

Prescription Trends in Complex Regional Pain Syndrome: A Retrospective Case-Control Study

OBJECTIVE

The objective of this study was to evaluate discrepancies in prescription trends for analgesic medications in complex regional pain syndrome (CRPS) patients based on recommendations in the literature.

DESIGN

We conducted a retrospective case-control study.

SUBJECTS

A total of 2510 CRPS patients and 2510 demographic-matched controls participated in this study.

METHODS

The SlicerDicer feature in Epic was used to find patients diagnosed with CRPS I or II between January 2010 and November 2022. An equal number of age-, gender-, and race-matched controls without a CRPS diagnosis were retracted from Epic. General and CRPS-associated prescription frequencies for the following classes were retrieved for both cases and controls: benzodiazepines, bisphosphonates, calcitonin, capsaicin, neuropathic pain medications, NSAIDs, opioids, and steroids.

RESULTS

A total of 740 (29%) CRPS patients and 425 (17%) controls were prescribed benzodiazepines (95% CI 0.1-0.15), 154 (6.1%) CRPS patients and 52 (2.1%) controls were prescribed capsaicin (95% CI 0.03-0.05), 1837 (73%) CRPS patients and 927 (37%) controls were prescribed neuropathic pain medications (95% CI 0.05-0.34), 1769 (70%) CRPS patients and 1217 (48%) controls were prescribed opioids (95% CI 0.19-0.25), 1095 (44%) CRPS patients and 1217 (48%) controls were prescribed steroids (95% CI 0.08-0.14), and 1638 (65%) CRPS patients and 1765 (70%) controls were prescribed NSAIDs (95% CI -0.08-0.02), p < 0.001 for all classes. With CRPS-associated prescriptions, (95% CI 0.05-0.16, p < 0.001) more CRPS patients were prescribed opioids (N = 398, 59%) than controls (N = 327, 49%).

CONCLUSIONS

CRPS is difficult to treat with significant variance in suggested treatment modalities. Based on the results of our study, there is a divergence between some published recommendations and actual practice.

Long-term efficacy and safety of neridronate treatment in patients with complex regional pain syndrome type 1: a pre-specified, open-label, extension study

Background

No data on the permanent and curative effect of bisphosphonate treatment in patients with complex regional pain syndrome type-1 (CRPS-1) are currently available. The aim of this pre-specified, open-label, observational study was to evaluate the long-term efficacy and safety of neridronate treatment.

Design

A pre-specified, open-label, extension study.

Methods

Patients treated with intramuscular (IM) placebo in the double-blind phase of the study were assigned to 100 mg intravenous (IV) neridronate treatment administered 4 times over 10 days. These patients, together with those previously treated with 400 mg IM neridronate, were followed for 1 year. Efficacy was assessed using a visual analogue scale (VAS) pain score. Changes in clinical signs and symptoms, quality of life (QoL) using the Short Form Health Survey (SF-36), and the McGill Pain Questionnaire were also assessed.

Results

Benefits on pain, clinical and functional measures were maintained and further improved over 12 months in most patients treated with neridronate administered either IM or IV. In IM-treated patients, the percentage of those defined as responders (VAS score reduction ≥ 50%) progressively increased up to day 360 to 32 of 35 patients (91.4%). Among the 27 patients referred to as responders at the end of the double-blind phase, 26 reported the same result at day 360 (96.3%). In IV-treated patients, a responder rate of 88% (22 out 25) was found at day 360 (p = 0.66 between groups). Consistent improvements were also observed for all clinical signs and functional questionnaire. No drug-related adverse events were reported during the study.

Conclusion

In patients with acute CRPS-1, the benefit in pain, clinical, and functional measures observed a few weeks after neridronate treatment administered either IM or IV is maintained and further improved over 12 months. Parenteral neridronate induces permanent disease remission preventing chronic pain and motor dysfunction.

Trial registration

EU Clinical Trials Register (EudraCT Number): 2014-001156-28.

Use of bisphosphonates in a retrospective case series of children and adolescents with complex regional pain syndrome

BACKGROUND

There is increasing evidence for the use of bisphosphonates to treat Complex Regional Pain Syndrome in adults. However, there are scarce data for their use in children with Complex Regional Pain Syndrome.

AIM

This retrospective case series aimed to analyze the effects of intravenous bisphosphonate use in children and adolescents with Complex Regional Pain Syndrome enrolled in a multidimensional pain treatment program.

METHODS

We analyzed the data of 16 patients (15 females and 1 male, mean age 14 ± 3 years) who received infusions of zoledronic acid (0.015 ± 0.0044mg/kg), pamidronate (0.72 ± 0.17mg/kg), or both depending on their initial response between October 2014 and December 2019. The primary endpoint of the study was the patient's global impression of change. Secondary outcomes included pain intensity, physical function, role function (school attendance), need for pain medications, and adverse effects.

RESULTS

Nine of 16 patients reported meaningful improvements (global impressions of change of 84% or higher) at a median follow-up time of 16 (8-21) months after their last infusion of bisphosphonates. There were also meaningful reductions in pain intensity and the need for pain medications. There was an increase in the proportion of patients with minimal or without physical disability, and almost all patients normalized their school activities. Thirteen patients (81%) reported adverse effects, mostly flu-like symptoms, for a few days after the infusion.

CONCLUSION

The use of bisphosphonate infusions may represent an effective treatment option for children with Complex Regional Pain Syndrome, not responding to multidisciplinary pain treatment programs.

Intramuscular neridronate for the treatment of complex regional pain syndrome type 1: a randomized, double-blind, placebo-controlled study

Background:

Complex regional pain syndrome type-1 (CRPS-1) is a severely disabling painful disease challenging to treat. This multicenter, randomized, double-blind placebo-controlled trial examined the efficacy of intramuscular (i.m.) neridronate in CRPS-1 patients.

Methods:

A total of 78 patients diagnosed with CRPS-1 (aged 59.5 ± 10.3, 66.7% female) were randomly assigned to 25 mg (i.m.) neridronate (N = 41) given once daily for 16 consecutive days or placebo control (N = 37). Efficacy was assessed after 30 days using a visual analogue scale (VAS) pain score and the number of patients achieving ⩾50% reduction in VAS score. Change in clinical signs and symptoms, quality of life (QoL) using Short Form Health Survey (SF-36) and the McGill Pain Questionnaire were also assessed.

Results:

After 30 days, VAS score decreased significantly to a greater extent in neridronate-treated patients versus placebo (31.9 ± 23.3 mm versus 52.3 ± 27.8 mm, p = 0.0003). Furthermore, the proportion of patients achieving a VAS reduction of ⩾50% was greater in the neridronate group (65.9% versus 29.7%, p = 0.0017). Clinical signs and symptoms were improved significantly in the neridronate group versus placebo for edema (72.5% versus 79.9%, p = 0.03), pain during motion (70% versus 83.3%, p = 0.0009), allodynia (20% versus 63.3%, p = 0.0004), and hyperalgesia (20% versus 56.7%, p = 0.0023). Whereas no difference was observed for QoL measures using the SF-36 questionnaire, three of the four pain variables using the McGill Pain Questionnaire improved significantly in the neridronate group. No serious drug-related adverse events were reported during the study.

Conclusion:

In patients with acute CRPS-1, i.m. injections of 25 mg neridronate were associated with clinically relevant benefit compared with placebo controls.

Trial registration:

EU Clinical Trials Register: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-001156-28

Intramuscular Clodronate in Long-Term Treatment of Symptomatic Knee Osteoarthritis: A Randomized Controlled Study

Background and Objective

Clodronate is a nitrogen-free bisphosphonate that is widely and effectively used in the treatment of many osteo-metabolic disorders. The objective of our study was to evaluate the effectiveness of clodronate in reducing pain and bone marrow edema in knee osteoarthritis.

Methods

In total, 74 patients were included in the study. Group 1 received intramuscular clodronate 200 mg daily for 15 days and then once weekly for the next 11.5 months; group 2 received intramuscular clodronate 200 mg daily for 15 days and then once weekly for the next 2.5 months. Visual analog scale (VAS) scores were recorded at baseline (T0) and after 30 days (T1), 3 months (T2), 6 months (T3), 9 months (T4), and 12 months (end of study; T5). We also evaluated functional status and use of paracetamol (T0, T1, T2, T3, T4, and T5) and changes in Whole Organ Magnetic Resonance Imaging Score (WORMS; T0, T2, and T5).

Results

Both groups had a statistically significant reduction in VAS score until 3 months. Group 1 then experienced further VAS reductions, whereas VAS scores for group 2 progressively increased. Pain, stiffness, and physical function also showed the same trend, as did bone marrow edema extension, which was evaluated with WORMS.

Conclusion

Our study indicates that intramuscular administration of a therapeutic dose of clodronate followed by a maintenance dose is effective in the management of symptomatic knee osteoarthritis, improving functional outcomes and reducing pain and bone marrow edema. Prolonged treatment increases the long-term efficacy of clodronate compared with the shorter schedule.

Complex regional pain syndrome: An updated comprehensive review

Complex regional pain syndrome (CRPS) is a complex disorder that can have a significant impact on the quality of life of a person with this syndrome. The diagnosis and treatment of CRPS are often difficult as there is no one confirmatory test and no one definitive treatment. Currently, the most widely accepted clinical diagnostic criteria are the Budapest criteria, which were developed by expert consensus. Though no one single treatment has been found to be universally effective, early detection and an interdisciplinary approach to treatment appear to be key in treating CRPS. This review aims to present up-to-date clinical information regarding the diagnosis and management of CRPS and highlight the potential issues with diagnosis in the neurological population. Ultimately, more research is needed to identify the exact etiology of CRPS in order to help target appropriate therapies. In addition, more randomized controlled trials need to be performed in order to test new therapies or combinations of therapies, including pharmacological, interventional, and behavioral therapies, to determine the best treatment options for this potentially debilitating disorder.

Complex regional pain syndrome secondary to sacrococcygeal dislocation following trauma to the lumbosacral region. Case report

Introduction: The complex regional pain síndrome (CRPS) is a rare condition characterized by inflammatory, vasomotor and central nervous system (CNS) involvement. Its clinical presentation can be subacute, acute or chronic, and may have severe effects on the patient’s quality of life.Case description: 21-year-old female patient with trauma in the lumbosacral region associated with pain and functional limitation. Diagnostic imaging showed sacrococcygeal dislocation with subsequent inflammatory and acute and chronic autonomic symptoms that were treated medically and surgically. The patient responded to treatment with long-term improvement of the symptoms.Discussion: In this case, CRPS occurred after trauma and caused subacute symptoms that became even more acute until reaching a chronic presentation. Inflammation, vasomotor dysfunction and CNS involvement made this case a multidisciplinary diagnostic and therapeutic challenge.Conclusion: CRPS is a rare disease that is difficult to diagnose. However, diagnosis should be timely in order to initiate personalized treatment, since this disease considerably affects the patient’s quality of life.

Pharmacology of bisphosphonates in pain

The treatment of pain, in particular, chronic pain, remains a clinical challenge. This is particularly true for pain associated with severe or rare conditions, such as bone cancer pain, vulvodynia, or complex regional pain syndrome. Over the recent years, there is an increasing interest in the potential of bisphosphonates in the treatment of pain, although there are few papers describing antinociceptive and anti-hypersensitizing effects of bisphosphonates in various animal models of pain. There is also increasing evidence for clinical efficacy of bisphosphonates in chronic pain states, although the number of well-controlled studies is still limited. However, the mechanisms underlying the analgesic effects of bisphosphonates are still largely elusive. This review provides an overview of preclinical and clinical studies of bisphosphonates in pain and discusses various pharmacological mechanisms that have been postulated to explain their analgesic effects. LINKED ARTICLES: This article is part of a themed issue on The molecular pharmacology of bone and cancer-related bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.

Bone microstructure is significantly altered in CRPS-affected distal tibiae as detected by HR-pQCT: a retrospective cross-sectional study

In the course of complex regional pain syndrome (CRPS), local osteopenia in the subchondral/subcortical areas of the affected limb represents a central manifestation. Mechanistic aspects of CRPS-associated pathologies remain unclear, and knowledge about bone morphology in CRPS-affected areas is rare. The aim of this study was to assess trabecular and cortical bone microstructure in patients with CRPS of the distal tibiae. We retrospectively analysed 14 women diagnosed with unilateral CRPS type I of the lower limb whose affected and unaffected distal tibiae were examined by high-resolution peripheral quantitative computed tomography (HR-pQCT). Laboratory tests included serum levels of calcium, phosphate, 25-hydroxyvitamin D, bone alkaline phosphatase, parathyroid hormone, osteocalcin and urinary levels of deoxypyridinoline (DPD). Bone mineral density was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and both proximal femurs. Average urinary DPD levels, a biochemical marker of bone resorption, were elevated in the examined patient cohort (7.1 ± 1.9 nmol/mmol, reference 3.0-7.0 nmol/mmol). According to HR-pQCT, CRPS-affected distal tibiae showed significantly lower values of cortical BMD and cortical thickness compared to the unaffected contralateral side. Also, bone volume relative to total volume was significantly lower. Trabecular number and trabecular thickness tended to be lower in the affected tibiae. CRPS is associated with significant alterations in bone microstructure of the affected tibiae. Increased bone resorption seems to play a crucial role within a multifactorial process of CRPS-mediated bone atrophy. HR-pQCT could possibly serve as a diagnostic tool in specific CRPS therapy.

Complex Regional Pain Syndrome: An update

Complex regional pain syndrome (CRPS) is a perplexing painful syndrome of the extremities usually following a harmful event. It is distinguished in two types, mainly depending on the presence of nerve injury. Although its prevalence may vary depending on social and ethnic factors, middle-aged women seem to suffer most often and the upper limb is the most commonly affected extremity. Apart from pain, which is the dominating feature, the clinical picture unfolds across several domains: sensory, motor, autonomic and trophic. This syndrome develops in two phases, the acute (warm) phase, with the classic symptoms of inflammation, and the chronic (cold) phase, often characterized by trophic changes of the soft tissues and even bones. Although the syndrome has been studied for over two decades, no imaging or laboratory test has been established for the diagnosis and recently proposed diagnostic criteria have not yet been validated and are only occasionally applied. Its pathophysiology is still quite obscure, although the most likely mechanisms involve the classic and neurogenic paths of inflammation mediated by cytokines and neuropeptides, intertwined with changes of the autonomic and central nervous system, psychological mechanisms and, perhaps, autoimmunity. Although plenty of treatment modalities have been tried, none has been proven unequivocally efficacious. Apart from information and education, which should be offered to all patients, the most effective pharmacological treatments seem to be bisphosphonates, glucocorticoids and vasoactive mediators, while physical therapy and rehabilitation therapy also make part of the treatment.

Bimalleolar Fracture: A Unique Case of Complication of Complex Regional Pain Syndrome of Lower Extremity After Prolonged Undue Immobilisation

Introduction:

The complex regional pain syndrome (CRPS) is an agonizing and disabling condition that can affect one or more extremities. Contrary to expectation, sporadic case reports about lower limb CRPS are present in literature. The usual sequence of events with respect to CRPS has always been prior trauma or inciting event, leading to manifestations. We hereby present a case of prolonged and undue immobilization without physical therapy, leading to CRPS in a susceptible phenotype. However, the unique feature of this case was severity of osteoporosis leading to bimalleolar fracture. To the best of our knowledge, there has been no case report of CRPS, leading to fracture.

Case Report:

A 30-year-old female presented 2 months after trauma to the right ankle due to a fall from a bike. A radiograph of the ankle demonstrated no evidence of any bony injury. As per records, there was no evidence of ligament injury based on magnetic resonance imaging evaluation. As the patient had severe pain and swelling, she underwent conservative treatment in the form of lower limb immobilization in a non-weight-bearing below knee splintage for a period of 8 weeks. After removal of the splintage, the patient continued to have severe pain and swelling and was unable to bear weight. At this point of time, the patient presented to our clinic where follow-up radiographs demonstrated a bimalleolar fracture of the right ankle and diffuse osteoporosis involving talus-calcaneusand metatarsals. After thorough exclusion of other metabolic bone diseases based on various laboratory parameters, the diagnosis of CRPS was made as per Budapest criteria.

The case here was diligently managed with multidisciplinary approach. It emphasized on the well-designed rehabilitation of the affected extremity to interrupt the vicious cycle of disuse along with well-controlled analgesia, cognitive psychotherapy, and supervised regular physical therapy. Meticulous medical management included bisphosphonates, careful balance of analgesics including nonsteroidal anti-inflammatory drugs, opioids, and beta-blockers.

Conclusion:

This case report highlights the importance of multimodal stepped care approach in CRPS 1 involving ankle joint. Our report also reiterates the relevance of early mobilization and avoiding undue immobilization.

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.

Allodynia and hyperalgesia: review

The main purpose was to highlight the problem of hyperalgesia and allodynia. Main anatomic structures, which participate in nociception were mentioned in this article, with pathologic and pathophysiologic changes, that can be caused by hyperalgesia and allodynia. Main methods of diagnostics and assessment of mentioned symptoms were represented along with the modern approaches to treatment and prevention.

Predictors of Responsiveness to Bisphosphonate Treatment in Patients with Complex Regional Pain Syndrome Type I: A Retrospective Chart Analysis

Objective

The aim of this study was to assess whether the effectiveness of bisphosphonate infusion in patients with complex regional pain syndrome type I (CRPS-I) is influenced by variables related to patient and/or disease characteristics.

Methods

This is a retrospective analysis of patients referred in the last five years to our rheumatologic tertiary care center, all fulfilling the Budapest CRPS-I diagnostic criteria and treated with three different bisphosphonate schedules (clodronate, pamidronate, and neridronate). For every subject, demographic and clinical variables were retrieved and retrospectively analyzed. We identified variables that independently influenced the therapeutic outcome of patients by a logistic regression analysis. For exploratory purposes, the effectiveness of the different bisphosphonate treatments employed was compared.

Results

Among the 194 patients included in the analysis, the overall therapeutic response rate was 71.6%. Logistic regression analysis showed that the independent predictive variables for therapeutic effectiveness were disease duration (odds ratio [OR] = 0.83, 95% confidence interval [CI] = 0.72-0.96 for a one-month increment), fracture as a predisposing event (OR = 3.23, 95% CI = 1.29-8.03), and "warm" disease subtype (OR = 4.88, 95% CI = 1.57-15.20). These variables were found to influence the odds of responsiveness when analyzed together with age at onset, gender, and disease localization. No significant difference in therapeutic effectiveness was found by comparing the three different bisphosphonate schedules employed.

Conclusion

Early disease, fracture as a predisposing event, and "warm" disease subtype are predictors of responsiveness to bisphosphonate treatment in patients with CRPS-I.

Effectiveness of complex regional pain syndrome treatment: A systematic review

Complex regional pain syndrome (CRPS) is a descriptive term for a complex of symptoms and signs typically occurring following trauma of the extremity. Typical symptomatology includes severe pain, swelling, vasomotor instability and functional impairment of the affected limb. At present there is no one, effective method of treatment of the condition. A large number of treatments have been investigated but major multicentre randomized controlled trials are lacking. This study presents the results of a systematic review of the evidence on effectiveness of treatment methods in CRPS. It is a follow-up to earlier reviews of randomized controlled trials on CRPS treatment published between 1966 and 2016.

RESULTS

The review of randomized controlled trials showed that only bisphosphonates were found to give uniformly positive effects, statistically significantly better than placebo. Improvement has been reported with topical dimethyl sulfoxide, systemic steroids, spinal cord stimulation and graded motor imagery/mirror therapy programmes. The available evidence does not support the use of other treatments in CRPS, however they are frequently used in clinical practice.

CONCLUSION

Available evidence, although numerous, does not necessarily reflect what is truly effective and what is sham in the management of CRPS.

Treatment of complex regional pain syndrome: an updated systematic review and narrative synthesis

PURPOSE

Although multiple treatments have been advocated for complex regional pain syndrome (CRPS), the levels of supportive evidence are variable and sometimes limited. The purpose of this updated review is to provide a critical analysis of the evidence pertaining to the treatment of CRPS derived from recent randomized-controlled trials (RCTs).

SOURCE

The MEDLINE, EMBASE, Psychinfo, and CINAHL databases were searched to identify relevant RCTs conducted on human subjects and published in English between 1 May 2009 and 24 August 2017.

PRINCIPAL FINDINGS

The search yielded 35 RCTs of variable quality pertaining to the treatment of CRPS. Published trials continue to support the use of bisphosphonates and short courses of oral steroids in the setting of CRPS. Although emerging evidence suggests a therapeutic role for ketamine, memantine, intravenous immunoglobulin, epidural clonidine, intrathecal clonidine/baclofen/adenosine, aerobic exercise, mirror therapy, virtual body swapping, and dorsal root ganglion stimulation, further confirmatory RCTs are warranted. Similarly, trials also suggest an expanding role for peripheral sympathetic blockade (i.e., lumbar/thoracic sympathetic, stellate ganglion, and brachial plexus blocks).

CONCLUSIONS

Since our prior systematic review article (published in 2010), 35 RCTs related to CRPS have been reported. Nevertheless, the quality of trials remains variable. Therefore, further research is required to continue investigating possible treatments for CRPS.

Alternatives to Opioids in the Pharmacologic Management of Chronic Pain Syndromes: A Narrative Review of Randomized, Controlled, and Blinded Clinical Trials

Chronic pain exerts a tremendous burden on individuals and societies. If one views chronic pain as a single disease entity, then it is the most common and costly medical condition. At present, medical professionals who treat patients in chronic pain are recommended to provide comprehensive and multidisciplinary treatments, which may include pharmacotherapy. Many providers use nonopioid medications to treat chronic pain; however, for some patients, opioid analgesics are the exclusive treatment of chronic pain. However, there is currently an epidemic of opioid use in the United States, and recent guidelines from the Centers for Disease Control (CDC) have recommended that the use of opioids for nonmalignant chronic pain be used only in certain circumstances. The goal of this review was to report the current body of evidence-based medicine gained from prospective, randomized-controlled, blinded studies on the use of nonopioid analgesics for the most common noncancer chronic pain conditions. A total of 9566 studies were obtained during literature searches, and 271 of these met inclusion for this review. Overall, while many nonopioid analgesics have been found to be effective in reducing pain for many chronic pain conditions, it is evident that the number of high-quality studies is lacking, and the effect sizes noted in many studies are not considered to be clinically significant despite statistical significance. More research is needed to determine effective and mechanism-based treatments for the chronic pain syndromes discussed in this review. Utilization of rigorous and homogeneous research methodology would likely allow for better consistency and reproducibility, which is of utmost importance in guiding evidence-based care.

Three cases of type-1 complex regional pain syndrome after elective total hip replacement

Complex regional pain syndrome (CRPS) constitutes an atypical cause of pain after orthopaedic procedures. To our knowledge, there is a paucity of literature reporting this syndrome after total hip arthroplasty (THR), since only two case reports have been published. We thenceforth describe the clinical outcome of three cases of type-1 CRPS developed after elective THR, two of them initially diagnosed with secondary osteoarthritis whereas the remaining one presented a sequel of a failed osteosynthesis that required conversion to THR. Remission of disease was found at an average seven months (range: 4–9). Medical treatment involved a combined therapy of pain management, bisphosphonates and intense physical therapy. One patient was additionally treated with a corticosteroid blockade of his right sympathetic lumbar ganglia. None of the patients required surgical treatment. At final follow-up, physical examinations and imaging were negative for disease.

Bisphosphonates Inhibit Pain, Bone Loss, and Inflammation in a Rat Tibia Fracture Model of Complex Regional Pain Syndrome

BACKGROUND

Bisphosphonates are used to prevent the bone loss and fractures associated with osteoporosis, bone metastases, multiple myeloma, and osteogenesis deformans. Distal limb fractures cause regional bone loss with cutaneous inflammation and pain in the injured limb that can develop into complex regional pain syndrome (CRPS). Clinical trials have reported that antiresorptive bisphosphonates can prevent fracture-induced bone loss, inhibit serum inflammatory cytokine levels, and alleviate CRPS pain. Previously, we observed that the inhibition of inflammatory cytokines or adaptive immune responses attenuated the development of pain behavior in a rat fracture model of CRPS, and we hypothesized that bisphosphonates could prevent pain behavior, trabecular bone loss, postfracture cutaneous cytokine upregulation, and adaptive immune responses in this CRPS model.

METHODS

Rats underwent tibia fracture and cast immobilization for 4 weeks and were chronically administered either subcutaneously perfused alendronate or oral zoledronate. Behavioral measurements included hindpaw von Frey allodynia, unweighting, warmth, and edema. Bone microarchitecture was measured by microcomputed tomography, and bone cellular activity was evaluated by static and dynamic histomorphometry. Spinal cord Fos immunostaining was performed, and skin cytokine (tumor necrosis factor, interleukin [IL]-1, IL-6) and nerve growth factor (NGF) levels were determined by enzyme immunoassay. Skin and sciatic nerve immunoglobulin levels were determined by enzyme immunoassay.

RESULTS

Rats with tibia fractures developed hindpaw allodynia, unweighting, warmth, and edema, increased spinal Fos expression and trabecular bone loss in the lumbar vertebra and bilateral distal femurs as measured by microcomputed tomography, increased trabecular bone resorption and osteoclast surface with decreased bone formation rates, increased cutaneous inflammatory cytokine and NGF expression, and elevated immunocomplex deposition in skin and nerve. Alendronate (60 μg/kg/d subcutaneously [s.c.]) or zoledronate (3 mg/kg/d orally) treatment for 28 days, started at the time of fracture, completely inhibited the development of hindpaw allodynia and reduced hindpaw unweighting by 44% ± 13% and 58% ± 5%, respectively. Orally administered zoledronate (3 mg/kg/d for 21 days) treatment also completely reversed established allodynia and unweighting when started at 4 weeks postfracture. Histomorphometric and microcomputed tomography analysis demonstrated that both the 3 and 60 μg/kg/d alendronate treatments reversed trabecular bone loss (an 88% ± 25% and 188% ± 39% increase in the ipsilateral distal femur BV/TV, respectively) and blocked the increase in osteoclast numbers and erosion surface observed in bilateral distal femurs and in L5 vertebra of the fracture rats. Alendronate treatment inhibited fracture-induced increases in hindpaw inflammatory mediators, reducing postfracture levels of tumor necrosis factor by 43% ± 9%, IL-1 by 60% ± 9%, IL-6 by 56% ± 14%, and NGF by 37% ± 14%, but had no effect on increased spinal cord Fos expression, or skin and sciatic nerve immunocomplex deposition.

CONCLUSIONS

Collectively, these results indicate that bisphosphonate therapy inhibits pain, osteoclast activation, trabecular bone loss, and cutaneous inflammation in the rat fracture model of CRPS, data supporting the hypothesis that bisphosphonate therapy can provide effective multimodal treatment for CRPS.

Bisphosphonates for treatment of Complex Regional Pain Syndrome type 1: A systematic literature review and meta-analysis of randomized controlled trials versus placebo

OBJECTIVES

Complex Regional Pain Syndrome Type 1 is a severely disabling pain syndrome with no definite established treatment. We have performed a systematic literature review and meta-analysis of all randomized controlled trials to assess the benefit of bisphosphonates on pain and function in patients with Complex Regional Pain Syndrome Type 1.

METHODS

A systematic literature search was performed in the Medline, Embase and Cochrane databases. Two authors selected independently blinded randomized trials comparing bisphosphonates to placebo on short-term (J30 to J40) and medium term pain (M2-M3), safety and function in patients with CRPS 1. The methodological quality of the studies was analyzed. Data were aggregated using the method of the inverse of the variance.

RESULTS

258 articles were identified. Four trials of moderate to good quality comprising 181 patients (90 in the bisphosphonate group and 91 in the placebo group) were included in this meta-analysis. Short-term pain Visual Analog Scale was significantly lower in the bisphosphonate group versus the placebo group (SMD=-2.6, 95%CI [-1.8, -3.4], P<0.001), as well as the medium term Visual Analog Scale pain (SMD=-2.5, 95%CI [-1.4, -3.6], P<0.001). There were more adverse events in the bisphosphonate group (35.5%) than in the placebo group (16.4%) with a relative risk of 2.1 (95%CI [1.3, 3.5], P=0.004) and a number needed to harm of 4.6, (95%CI [2.4, 168.0]) but no serious side effects.

CONCLUSIONS

Our results suggest that bisphosphonates reduce pain in patients with Complex Regional Pain Syndrome type 1. Other studies are needed to determine their effectiveness.

Complex regional pain syndrome: a recent update

Complex regional pain syndrome (CRPS) is a debilitating condition affecting the limbs that can be induced by surgery or trauma. This condition can complicate recovery and impair one’s functional and psychological well-being. The wide variety of terminology loosely used to describe CRPS in the past has led to misdiagnosis of this condition, resulting in poor evidence-base regarding the treatment modalities available and their impact. The aim of this review is to report on the recent progress in the understanding of the epidemiology, pathophysiology and treatment of CRPS and to discuss novel approaches in treating this condition.

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.

Bisphosphonates in multicentric osteolysis, nodulosis and arthropathy (MONA) spectrum disorder - an alternative therapeutic approach

Multicentric osteolysis, nodulosis and arthropathy (MONA) spectrum disorder is a rare inherited progressive skeletal disorder caused by mutations in the matrix metalloproteinase 2 (MMP2) gene. Treatment options are limited. Herein we present successful bisphosphonate therapy in three affected patients. Patients were treated with bisphosphonates (either pamidronate or zoledronate) for different time periods. The following outcome variables were assessed: skeletal pain, range of motion, bone densitometry, internal medical problems as well as neurocognitive function. Skeletal pain was dramatically reduced in all patients soon after initiation of therapy and bone mineral density increased. Range of motion did not significantly improve. One patient is still able to walk with aids at the age of 14 years. Neurocognitive development was normal in all patients. Bisphosphonate therapy was effective especially in controlling skeletal pain in MONA spectrum disorder. Early initiation of treatment seems to be particularly important in order to achieve the best possible outcome.

The clinical relevance of complex regional pain syndrome type I: The Emperor's New Clothes

The management of patients with chronic pain is a nearly daily challenge to rheumatologists, neurologists, orthopedic surgeons, pain specialists and indeed a issue in nearly every clinical practice. Among the myriad of causes of pain are often included a unique syndrome, generally referred to as complex regional pain syndrome type I (CRPS). Unfortunately CRPS I has become a catch all phase and there are serious questions on whether it exists at all; this has led to an extraordinary number of poorly defined diagnostic criteria. It has also led to an etiologic quagmire that includes features as diverse as autoimmunity to simple trauma. These, in turn, have led to overdiagnosis and often overzealous use of pain medications, including narcotics. In a previous paper, we raised the issue of whether CRPS type I reflected a valid diagnosis. Indeed, the diagnostic criteria for CRPS I, and therefore the diagnosis itself, is unreliable for a number of reasons: 1) the underlying pathophysiology of the signs and symptoms of CPRS I are not biologically plausible; 2) there are no consistent laboratory or imaging testing available; 3) the signs and symptoms fluctuate over time without a medical explanation; 4) the definitions of most studies are derived from statistical analysis with little consideration to required sample size, i.e. power calculations; 5) interobserver reliability in the assessment of the signs and symptoms are often only fair to moderate, and agreement on the diagnosis of "CRPS I" is poor. Even physicians who still believe in the concept of "CRPS I" admit that it is vastly overdiagnosed and has become a diagnosis of last resort, often without a complete differential diagnosis and an alternative explanation. Finally, one of the most convincing arguments that there is no clinical entity as "CRPS I" comes from the enormous heterogeneity in sign and symptom profiles and the heterogeneity of pathophysiological mechanisms postulated. This observation is underscored by the diversity of responses among "CRPS I" patients to essentially all treatment modalities. It has even led to the concept that the signs and symptoms of CRPS can spread throughout the body, as if it is an infectious disease, without any medical plausible explanation. If true progress is to be made in helping patients with pain, it will require entirely new and different concepts and abandoning CRPS I as a legitimate diagnosis.

[Complex regional pain syndrome following distal fractures of the radius : Epidemiology, pathophysiological models, diagnostics and therapy]

The complex regional pain syndrome (CRPS) still represents an incompletely etiologically understood complication following fractures of the distal radius. The incidence of CRPS following fractures of the distal radius varies between 1 % and 37 %. Pathophysiologically, a complex interaction of inflammatory, somatosensory, motor and autonomic changes is suspected, leading to a persistent maladaptive response and sensitization of the central and peripheral nervous systems with development of the corresponding symptoms. Decisive for the diagnostics are a detailed patient medical history and a clinical hand surgical, neurological and pain-related examination with confirmation of the Budapest criteria. Among the types of apparatus used for diagnostics, 3‑phase bone scintigraphy and temperature measurement have a certain importance. A multimodal therapy started as early as possible is the most promising approach for successful treatment. As part of a multimodal rehabilitation the main focus of therapy lies on pain relief and functional aspects.

Management of patients with complex regional pain syndrome type I

Complex regional pain syndrome type I (CRPS-I) includes different conditions characterized by regional pain and sensory, motor, sudomotor, vasomotor, and/or trophic findings, affecting a peripheral limb usually after a noxious event, such as a trauma or surgery. The pathophysiology is still poorly understood. Limited data are available on the incidence of CRPS-I, and the disease is underestimated and under-diagnosed. The disease shows a female preponderance approximately 3:1 with a peak age of incidence around the 5th and 6th decade. The available diagnostic criteria for CRPS-I rely on clinical criteria that are unfortunately focused on the signs and symptoms of the chronic and late disease, while little emphasis is given to the typical imaging (X-rays, bone scintigraphy, MRI) findings of the early phase. Over the last decades, several therapies have been proposed but the few studies available are often too small to be conclusive and rarely evolved to randomized controlled trials (RCTs). On the basis of the results of a few RCTs, only short courses of high bisphosphonate doses appear to provide substantial benefits. The best results are seen in patients in the early phase of the disease, often with the persistent remission or complete healing of the conditions. Since the only accredited mechanism of action of bisphosphonates is the suppression of osteoclastic bone resorption, it is likely the initial dramatic bone loss plays a role in the maintenance and evolution of CRPS-I. Short courses of high doses of bisphosphonates should be considered the treatment of choice for patients with CRPS-I.

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.

Treatment of complex regional pain syndrome type I with bisphosphonates

Complex regional pain syndrome type I (CRPS-I) is a common and disabling disorder affecting a peripheral limb, usually developing after a trauma to an extremity. CRPS-I is characterised by presence of spontaneous pain, allodynia and hyperalgesia, disproportionate to the inciting event and by a variety of autonomic disturbances and trophic abnormalities. The pathophysiology of CRPS-I has not been fully understood. Experimental models have suggested that an initial triggering event may produce the release of proinflammatory neuropeptides and cytokines, generating a sort of neurogenic inflammation. Thereafter, increased microvascular permeability and intramedullary pressure, reduced oxygen extraction and cellular hypoxia maintain and make the disease worse, producing metabolic tissue acidosis. In this context, it is probable that, far from being a key player, the sympathetic nervous system contributes interacting with these mechanisms and producing vasomotor disturbances. Bisphosphonates (BPs) are potent inhibitors of osteoclastic activity widely used for the management of osteoporosis and other metabolic bone diseases. Their primary pharmacological action is the reduction of bone turnover. An enhanced osteoclastic activity has never been clearly demonstrated in CRPS-I. Therefore, it is likely that the positive effects of BPs in this condition are not related to their antiresorptive properties, but to a more complex interaction between these pharmacological agents and the pathophysiological mechanisms underlying CRPS-I. Results of several clinical trials have suggested the potential beneficial effects of BPs in CRPS-I. In five randomised controlled trials, oral and intravenous alendronate and intravenous clodronate, pamidronate and neridronate demonstrated to be effective in reducing pain and improving physical function in patients presenting with CRPS-I, with a good profile of safety and tolerability. Although these trials have a number of limitations, including the small samples enrolled, there is sufficient evidence to support the use of BPs as agents of choice in the management of CRPS-I.

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.

Endocrinology of bone/brain crosstalk

Bone metabolism is regulated by the action of two skeletal cells: osteoblasts and osteoclasts. This process is controlled by many genetic, hormonal and lifestyle factors, but today more and more studies have allowed us to identify a neuronal regulation system termed 'bone-brain crosstalk', which highlights a direct relationship between bone tissue and the nervous system. The first documentation of an anatomic relationship between nerves and bone was made via a wood cut by Charles Estienne in Paris in 1545. His diagram demonstrated nerves entering and leaving the bones of a skeleton. Later, several studies were conducted on bone innervation and, as of today, many observations on the regulation of bone remodeling by neurons and neuropeptides that reside in the CNS have created a new research field, that is, neuroskeletal research.

Complex regional pain syndrome: From diagnosis to rehabilitation

Complex regional pain syndrome (CRPS) is a debilitating pathology characterised by intense chronic pain associated with vasomotor, sensory and motor dysfunction of the affected limb. Although the pathophysiology of CRPS is not fully understood, it is recognised that inflammatory processes and autonomic dysfunction are involved. These processes are associated with peripheral and central sensitisation as well as changes in brain structure and function, and are reflected in the clinical presentation of CRPS. CRPS management requires an interdisciplinary team and requires the therapeutic approach to be individualised. With regard to pharmacological treatment, bisphosphonates, corticosteroids, ketamine and anticonvulsants have been demonstrated to be effective for CRPS management. Psychotherapy, including cognitive-behavioural therapy, has produced promising results but more studies are needed to confirm its efficacy. Among rehabilitation interventions, there is evidence of the efficacy of physiotherapy and occupational therapy in diminishing CRPS symptoms and achieving a higher level of functioning. In this regard, the rehabilitation modality that seems the most promising according to the actual literature is graded motor imagery, which can help to reverse the maladaptive neuroplasticity occurring in CRPS.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Clinical development of neridronate: potential for new applications

Neridronate is an aminobisphosphonate, licensed in Italy for the treatment of osteogenesis imperfecta (OI) and Paget's disease of bone (PDB). A characteristic property of neridronate is that it can be administered both intravenously and intramuscularly, providing a useful system for administration in homecare. In this review, we discuss the latest clinical results of neridronate administration in OI and PDB, as well as in osteoporosis and other conditions. We will focus in particular on the latest evidence of the effect of neridronate on treatment of complex regional pain syndrome type I.

Complex regional pain syndrome: practical diagnostic and treatment guidelines, 4th edition

OBJECTIVE

This is the fourth edition of diagnostic and treatment guidelines for complex regional pain syndrome (CRPS; aka reflex sympathetic dystrophy).

METHODS

Expert practitioners in each discipline traditionally utilized in the treatment of CRPS systematically reviewed the available and relevant literature; due to the paucity of levels 1 and 2 studies, less rigorous, preliminary research reports were included. The literature review was supplemented with knowledge gained from extensive empirical clinical experience, particularly in areas where high-quality evidence to guide therapy is lacking.

RESULTS

The research quality, clinical relevance, and "state of the art" of diagnostic criteria or treatment modalities are discussed, sometimes in considerable detail with an eye to the expert practitioner in each therapeutic area. Levels of evidence are mentioned when available, so that the practitioner can better assess and analyze the modality under discussion, and if desired, to personally consider the citations. Tables provide details on characteristics of studies in different subject domains described in the literature.

CONCLUSIONS

In the humanitarian spirit of making the most of all current thinking in the area, balanced by a careful case-by-case analysis of the risk/cost vs benefit analysis, the authors offer these "practical" guidelines.

Treatment of complex regional pain syndrome type I with neridronate: a randomized, double-blind, placebo-controlled study

OBJECTIVE

Complex regional pain syndrome type I (CRPS-I) is a severely disabling pain syndrome for which no definite treatment has been established. The aim of this multi-centre, randomized, double-blind placebo-controlled trial was to test the efficacy of the amino-bisphosphonate neridronate in patients with CRP-I.

METHODS

Eighty-two patients with CRP-I at either hand or foot were randomly assigned to i.v. infusion of 100 mg neridronate given four times over 10 days or placebo. After 50 days the former placebo patients were given open label the same regimen of neridronate.

RESULTS

Within the first 20 days, visual analogue scale (VAS) score decreased significantly more in the neridronate group. In the following 20 days, VAS remained unchanged in the placebo group and further decreased in the active group by 46.5 mm (95% CI -52.5, -40.5) vs 22.6 mm (95% CI -28.8, -16.3) for placebo group (P < 0.0001). Significant improvements vs placebo were observed also for a number of other indices of pain and quality of life. During the open-extension phase in the formerly placebo group the results of treatment were superimposable on those seen during the blind phase in the active group. A year later none of the patients was referring symptoms linked to CRPS-I.

CONCLUSION

In patients with acute CRPS-I, four i.v. infusions of neridronate 100 mg are associated with clinically relevant and persistent benefits. These results provide conclusive evidence that the use of bisphosphonates, at appropriate doses, is the treatment of choice for CRPS-I.

TRIAL REGISTRATION

EU Clinical Trials Register, https://www.clinicaltrialsregister.eu/, 2007-003372-18.

The Charcot joint: a modern neurologic perspective

The Charcot joint, or Charcot neuroarthropathy, is a syndrome that was described over 140 years ago but one with very little exposure in the neurologic literature. We present a case recently seen and then discuss the history, epidemiology, pathophysiology, clinical features, and diagnosis of acute and chronic Charcot joint disease with particular emphasis on the value and limitations of imaging. A diagnostic algorithm is proposed. We also review the therapeutic strategies available for acute and chronic Charcot joints with a treatment algorithm. This review is aimed at enhancing the awareness of neurologists regarding Charcot neuroarthropathy, because they are often the principal caregivers for patients with peripheral neuropathy. We hope to promote early detection of acute Charcot neuroarthropathy, thereby reducing or preventing the bony deformation of chronic Charcot neuroarthropathy.

Treatment of complex regional pain syndrome in adults: a systematic review of randomized controlled trials published from June 2000 to February 2012

Complex regional pain syndrome (CRPS) is a disabling pain condition with sensory, motor and autonomic manifestations. Uncertainty remains about how CRPS can be effectively managed. We conducted a systematic review of randomized controlled trials (RCTs) for treatment and prophylactic interventions for CRPS published during the period 2000-2012, building on previous work by another group reviewing the period 1966-2000. Bibliographic database searches identified 173 papers which were filtered by three reviewers. This process generated 29 trials suitable for further analysis, each of which was reviewed and scored by two independent reviewers for methodological quality using a 15-item checklist. A number of novel and potentially effective treatments were investigated. Analysing the results from both review periods in combination, there was a steep rise in the number of published RCTs per review decade. There is evidence for the efficacy of 10 treatments (3× strong--bisphosphonates, repetitive transcranial magnetic stimulation and graded motor imagery, 1× moderate and 6× limited evidence), and against the efficacy of 15 treatments (1× strong, 1× moderate and ×13 limited). The heterogeneity of trialled interventions and the pilot nature of many trials militate against drawing clear conclusions about the clinical usefulness of most interventions. This and the observed phenomenon of excellent responses in CRPS subgroups would support the case for a network- and multi-centre approach in the conduct of future clinical trials. Most published trials in CRPS are small with a short follow-up period, although several novel interventions investigated from 2000 to 2012 appear promising.