Reflex sympathetic dystrophy: changing concepts and taxonomy

Neural activity regulates autoimmune diseases through the gateway reflex

The brain, spinal cord and retina are protected from blood-borne compounds by the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB) and blood-retina barrier (BRB) respectively, which create a physical interface that tightly controls molecular and cellular transport. The mechanical and functional integrity of these unique structures between blood vessels and nervous tissues is critical for maintaining organ homeostasis. To preserve the stability of these barriers, interplay between constituent barrier cells, such as vascular endothelial cells, pericytes, glial cells and neurons, is required. When any of these cells are defective, the barrier can fail, allowing blood-borne compounds to encroach neural tissues and cause neuropathologies. Autoimmune diseases of the central nervous system (CNS) and retina are characterized by barrier disruption and the infiltration of activated immune cells. Here we review our recent findings on the role of neural activity in the regulation of these barriers at the vascular endothelial cell level in the promotion of or protection against the development of autoimmune diseases. We suggest nervous system reflexes, which we named gateway reflexes, are fundamentally involved in these diseases. Although their reflex arcs are not completely understood, we identified the activation of specific sensory neurons or receptor cells to which barrier endothelial cells respond as effectors that regulate gateways for immune cells to enter the nervous tissue. We explain this novel mechanism and describe its role in neuroinflammatory conditions, including models of multiple sclerosis and posterior autoimmune uveitis.

Reflex Sympathetic Dystrophy of the Right Hand following an Acute Traumatic Injury

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy, is a chronic neuropathic pain disorder with significant autonomic features. Recently, it has been recognized that CRPS is not simply a sympathetically mediated peripheral pain condition but rather a disease of the central nervous system as well. Herein, we present a case of a patient who presented with complaints of severe pain following a traumatic event, severing his extensor tendon of his right fifth finger. 

Complex regional pain syndrome: a focus on the autonomic nervous system

PURPOSE

Although autonomic features are part of the diagnostic criteria for complex regional pain syndrome (CRPS), the role of the autonomic nervous system in CRPS pathophysiology has been downplayed in recent years. The purpose of this review is to redress this imbalance.

METHODS

We focus in this review on the contribution of the autonomic nervous system to CRPS pathophysiology. In particular, we discuss regional sympathetic and systemic autonomic disturbances in CRPS and the mechanisms which may underlie them, and consider links between these mechanisms, immune disturbances and pain.

RESULTS

The focused literature research revealed that immune reactions, alterations in receptor populations (e.g., upregulation of adrenoceptors and reduced cutaneous nerve fiber density) and central changes in autonomic drive seem to contribute to regional and systemic disturbances in sympathetic activity and to sympathetically maintained pain in CRPS.

CONCLUSIONS

We conclude that alterations in the sympathetic nervous system contribute to CRPS pathology. Understanding these alterations may be an important step towards providing appropriate treatments for CRPS.

Incidence of and Risk Factors for Complex Regional Pain Syndrome Type 1 after Surgery for Distal Radius Fractures: A Population-based Study

This study aimed to evaluate the incidence rates of and risk factors for complex regional pain syndrome type 1 (CRPS-1) after surgery for distal radius fractures (DRFs). Using data from January 2007 to December 2014, we analysed the data from the Korean Health Insurance Review and Assessment (HIRA) service. After extracting the data of patients aged ≥18 years whose diagnostic and operation codes for DRFs were entered into the HIRA database, we analysed the incidence rates of and risk factors for CRPS-1. From 2007 to 2014, 172,194 DRFs were treated surgically. Within 1 year postoperatively, 1,103 CRPS-1 cases were diagnosed, with an incidence of 0.64%. On univariate and multivariate analyses, the risk factors that significantly correlated with the incidence of CRPS-1 included female sex, rheumatoid arthritis, open reduction, open fracture, and accompanying ulnar fracture, whereas old age, psychiatric disease, and external fixation were not statistically significant. The incidence of CRPS-1 after surgery for DRF was very low (0.64%) in South Korea. Careful monitoring is necessary for patients with complex fractures and rheumatoid arthritis who are at increased risk of developing CRPS-1.

Post-stroke shoulder pain subtypes classifying criteria: towards a more specific assessment and improved physical therapeutic care

BACKGROUND

Post-stroke Shoulder Pain (PSSP) is a common stroke-related syndrome that prolongs hospitalization and diminishes quality of life. PSSP studies were unsuccessful in clarifying pathophysiological mechanisms. Therefore, cohort's studies with greater variety of the sample and larger follow-up period could provide additional clinical data and may improve medical care.

OBJECTIVE

To classify people with PSSP and identify intergroup clinical differences, providing additional data useful for therapeutic care planning.

METHODS

One thousand individuals with stroke were selected from all levels of one health Area and followed up during one year. Demographic data, stroke clinical characteristics, stroke-related symptoms and rehabilitation parameters were collected. The shoulder muscle impairment was used to group participants into three clinical profiles: severe muscular impairment, moderate muscular impairment and low muscular impairment groups.

RESULTS

A total of 119 individuals were diagnosed with PSSP. The suggested classification criteria showed two groups that differed significantly in relation to the onset and duration of PSSP, presence of sensory and speech impairment, and spasticity. The outcomes did not firmly support the existence of a third suggested PSSP subtype.

CONCLUSIONS

PSSP may vary in onset, clinical manifestations, severity and syndrome duration. These results highlight the course of different clinical profiles and require multidisciplinary management approaches.

CRPS: what’s in a name? Taxonomy, epidemiology, neurologic, immune and autoimmune considerations

This account of the condition now termed complex regional pain syndrome (CRPS) spans approximately 462 years since a description embodying similar clinical features was described by Ambroise Paré in 1557. While reviewing its historical origins, the text describes why it became necessary to change the taxonomies of two clinical syndromes with similar pathophysiologies to one which acknowledges this aspect but does not introduce any mechanistic overtones. Discussed at length is the role of the sympathetic component of the autonomic nervous system (ANS) and why its dysfunction has both directly and indirectly influenced our understanding of the inflammatory aspects of CRPS. As the following article will show, our knowledge has expanded in an exponential fashion to include musculoskeletal, immune, autoimmune, central and peripheral nervous system and ANS dysfunction, all of which increase the complexity of its clinical management. A burgeoning literature is beginning to shed light on the mechanistic aspects of these syndromes and the increasing evidence of a genetic influence on such factors as autoimmunity, and its importance is also discussed at length. An important aspect that has been missing from the diagnostic criteria is a measure of disease severity. The recent validation of a CRPS Severity Score is also included.

Spinal Cord Stimulation in Chronic Pain: A Review of the Evidence

This review looks at the evidence for the effectiveness of spinal cord stimulation in various chronic pain states. Spinal cord stimulation can only be effective when appropriate dorsal column fibres in the spinal cord are preserved and able to be stimulated. Spinal cord stimulation has been shown to have little to offer for patients with some diagnoses. Although 50 to 60% of patients with failed back surgery syndrome obtain significant pain relief with this technique, the strength of the evidence available is insufficient to clearly advocate its use in all patients with this condition. Though limited in quantity and quality, better evidence exists for its use in neuropathic pain, complex regional pain syndrome, angina pectoris and critical limb ischaemia. There is a lack of high quality evidence relating to spinal cord stimulation due to difficulties in conducting randomized controlled trials in this area. Serious methodological problems are encountered in blinding, recruitment and assessment in nearly all published trials of spinal cord stimulation. Suggestions regarding appropriate methodologies for trials which would produce better quality evidence are summarized.

Complex regional pain syndrome - False hopes and miscommunications

Complex regional pain syndrome (CRPS) has been considered to be an autoimmune disease and there have been clinical trials with intravenous immunoglobulin. Often the etiology of the so-called CRPS diagnosis cannot be discerned and there are no validated instruments that provide functional metrics. The term complex regional pain syndrome (CRPS), coined in 1994 to describe patients in whom the pain is out of proportion to the injury, was actually a diagnosis proposed during the American Civil War, but was originally known as causalgia. Physicians have long observed similar sensitivity and inflammatory symptoms following periods of immobilization and disuse, which generally resolve within a few months of remobilization. Following the original description, persistent disproportionate pain would come to be known under many other names until researchers theorized that it was related to dysfunction in the sympathetic nervous system, after which it acquired the moniker, Reflex Sympathetic Dystrophy ("RSD"). In the latter quarter of the twentieth century, after researchers failed to prove the connection between the pain and the sympathetic nervous system, a small cadre of physicians-without rigorous science-invented CRPS. This new descriptor, CRPS, has become not only a diagnosis without objective data but with proposed criteria involving ambiguous signs and symptoms with low specificity. It has led to patients being treated erroneously with sympatholytic drugs, with or without pharmaceutical or surgical blockade of the sympathetic nervous system, unwarranted use of ketamine infusions, inappropriate use of narcotics and nerve stimulation. Intravenous immunoglobulin infusions have not been effective in the treatment of chronic pain. The indiscriminate use of pain medications to treat subjective symptoms of unclear diagnoses can be a risk factor for opioid and analgesic misuse or abuse.

Impact of the Autonomic Nervous System on the Skeleton

It is from the discovery of leptin and the central nervous system as a regulator of bone remodeling that the presence of autonomic nerves within the skeleton transitioned from a mere histological observation to the mechanism whereby neurons of the central nervous system communicate with cells of the bone microenvironment and regulate bone homeostasis. This shift in paradigm sparked new preclinical and clinical investigations aimed at defining the contribution of sympathetic, parasympathetic, and sensory nerves to the process of bone development, bone mass accrual, bone remodeling, and cancer metastasis. The aim of this article is to review the data that led to the current understanding of the interactions between the autonomic and skeletal systems and to present a critical appraisal of the literature, bringing forth a schema that can put into physiological and clinical context the main genetic and pharmacological observations pointing to the existence of an autonomic control of skeletal homeostasis. The different types of nerves found in the skeleton, their functional interactions with bone cells, their impact on bone development, bone mass accrual and remodeling, and the possible clinical or pathophysiological relevance of these findings are discussed.

Sport-related injury and pain classification

Pain is common in athletes, and pain management in sport has traditionally been equated with injury management. Although both pain and injury interfere with sport performance, they are not synonymous. Acute musculoskeletal injury commonly manifests as nociceptive pain, inflammatory pain, or both. Pain that persists beyond expected injury recovery must account for all potential contributors to pain, including ongoing biomechanical abnormalities, underlying pathophysiology, and psychosocial issues. Pain chronification involves multiple pathophysiologic and neurobehavioral processes that lead from acute injury-related pain to subacute and chronic pain, and must be distinguished from an ongoing biomechanical overuse pattern. The foundation of pain management in athletes is proper pain classification, which involves assessing for any combination of nociceptive/inflammatory pain, neuropathic pain, central sensitization, and autonomic/motor/affective manifestations of pain. Understanding this foundation is critical because there are scant evidence-based guidelines for the management of pain in sport. This chapter will explore the relationship of sport-related injury and pain, and will provide a management framework that is consistent with International Olympic Committee consensus.

Psychiatric Disorders in Complex Regional Pain Syndrome (CRPS): The Role of the Consultation-Liaison Psychiatrist

Background

Complex regional pain syndrome (CRPS) is a multifactorial disorder with complex aetiology and pathogenesis. At the outpatient pain clinic of Magdeburg University Hospital, all patients, without exception, are subject to permanent psychiatric care delivered by a consultation-liaison psychiatrist. In CRPS, psychological stabilization and treatment of the neuropathic aspects are equally important. The aim of this single-center retrospective study was to determine mental/psychiatric defects impairing pain processing at the time of investigation and show the effects of treating mental disorders and neuropathic pain with the same psychotropic drugs.

Method

On admission, the consultation-liaison psychiatrist examined the mental state of every patient in a semistructured interview according to AMDP (working group for methods and documentation in psychiatry). Due to the model of the Department of Anaesthesiology, we are able to compare the group of CRPS patients with all other outpatients treated for pain.

Results

The medical treatment of psychiatric dysfunction leads to an analgesic effect. Only every second CRPS patient had an additional psychiatric diagnosis, and 15.6% were diagnosed with depressive mood disorders and show a higher prevalence of depressive symptoms than the general population and exceed the mean for all patients treated in our pain clinic.

Conclusions

In neuropathies, treatment of the neuropathic pain has a modulating effect on mental disorders. As CRPS patients are frequently affected by depressions, and owing to the connection between depression and suicidal tendencies, patients should be seen by a consultation-liaison psychiatrist, and nonpsychiatrists should pay special attention to this patient group.

Epidemiology of complex regional pain syndrome in Korea: An electronic population health data study

Chronic regional pain syndrome (CRPS) is an inflammatory and neuropathic pain disorder characterized by the involvement of the autonomic nervous system with sensory, autonomic, motor, skin, and bone changes. At present, universally accepted consensus criteria for CRPS are not yet established, despite the diagnostic criteria proposed by the International Association for the Study of Pain (IASP). Various hypotheses for the pathophysiology of CRPS have been proposed; as a result, current therapeutic modalities are varied. General epidemiological data on CRPS are necessary for effective management. However, recent data on the epidemiology of CRPS in Korea are scarce. The aim of this study was to evaluate the incidence and other epidemiological features of CRPS in the general population in Korea. In this study on the epidemiology of CRPS in Korea, population-based medical data acquired from 51,448,491 subscribers to the National Health Insurance Service (NHIS) from 2011 to 2015 were analyzed, including the incidence, distribution by the CRPS type, regional distribution, monthly distribution, medical costs, and healthcare resource-utilization. The findings indicated that the incidence of CRPS in Korea was 29.0 per 100,000 person-years in 2015 and was correlated with patient age and sex. CRPS types included type I (63%) and type II (37%); moreover, the number of individuals with CRPS I have shown a growing trend since 2011. There was no monthly distribution, but there was regional variation according to the province. The medical departments managing CRPS I the most were orthopedics, internal medicine, anesthesiology and pain medicine, in order; however, patients with CRPS spent more money per visit in the departments of rehabilitation medicine, and anesthesiology and pain medicine. The incidence rate of CRPS in Korea was 29.0 per 100,000 person-years with an increasing trend, which was correlated with patient age in the 70s and female sex. CRPS type I was more common than CRPS type II; in addition, constant increase in medical expenses, regional imbalance, and differences in medical expense among medical specialties should be considered for early management of patients to reduce the disease burden in Korea. Sharing of knowledge about the diagnostic criteria of CRPS are also needed.

Sympathetic blocks for the treatment of complex regional pain syndrome: A case series

RATIONALE

To present the successful treatment of complex regional pain syndrome type -1 utilizing sympathetic blocks.

PATIENT CONCERNS

Severe pain interfering with activities of daily living and temporary disability secondary to complex regional pain syndrome.

DIAGNOSES

Complex regional pain syndrome type-1 with involvement of lower extremity (2 patients), and upper extremity (1 patient).

INTERVENTIONS

We report the management of 3 patients with diagnosis of complex regional pain syndrome type-1 by early institution of sympathetic blocks for diagnostic and therapeutic purposes. All 3 patients were able to tolerate physical therapy only after adequate pain relief had been achieved with institution of sympathetic blocks.

OUTCOMES

All 3 patients responded very favorably to sympathetic blocks with dramatic reversal of pathology. All patients reported almost complete resolution of pain, symptoms, and signs within 6 months duration after diagnosis of complex regional pain syndrome. All 3 patients were able to wean their pain medications and achieve normal activities of daily living without any significant limitations. All patients were able to return to full-time employment.

LESSONS

Treatment options are limited and there is lack of high quality research regarding the efficacy of sympathetic blocks in the treatment of complex regional pain syndrome. As presented in this case series, sympathetic blocks maybe very effective in the treatment of complex regional pain syndrome in a subset of patients. Thus, early institution of sympathetic blocks should be considered in complex regional pain syndrome prior to physical therapy and consideration of more invasive pain management interventions.

Lumbar Sympathetic Block with Botulinum Toxin Type A and Type B for the Complex Regional Pain Syndrome

A lumbar sympathetic ganglion block (LSB) is a therapeutic method for complex regional pain syndrome (CRPS) affecting the lower limbs. Recently, LSB with botulinum toxin type A and B was introduced as a novel method to achieve longer duration of analgesia. In this study, we compared the botulinum toxin type A (BTA) with botulinum toxin type B (BTB) in performing LSB on patients with CRPS. LSB was performed with either BTA or BTB on patients with CRPS in their lower extremities. The length of time taken for patients to return to the pre-LSB pain score and the adverse effect of LSB with BTA/BTB were investigated. The median length of time taken for the patients to return to the pre-LSB pain score was 15 days for the BTA group and 69 days for the BTB group (P = 0.002). Scores on a visual analogue scale decreased in the patients of both groups, and no significant adverse effects were experienced. In conclusion, the administration of either BTA or BTB for LSB is a safe method to prolong the sympathetic blocking effect in patients with CRPS. BTB is more effective than BTA to prolong the sympathetic blocking effect in CRPS patients.

Complex regional pain syndrome acute care pathways in England: Do they exist and what do they look like?

Introduction

Complex Regional Pain Syndrome is a condition with a high degree of morbidity and health costs to the National Health Service (NHS), characterised by persistent pain, sensory, motor, trophic and autonomic signs and symptoms. The British Orthopaedic Association (BOA) and the Royal College of Physicians (RCP) have recommended treatment guidelines and care pathways for the management of acute Complex Regional Pain Syndrome. The objective of this scoping exercise was to use Freedom of Information (FOI) requests to ascertain whether NHS Trusts in England had such pathways and what they looked like.

Methods

FOI requests were sent to 126 English NHS Trusts on 9 March 2017 on behalf of the Complex Regional Pain Syndrome Clinical and Research Network UK, asking: “What does your acute Complex Regional Pain Care Syndrome pathway look like?”

Results

Replies were received by 95 NHS Trusts and of these 84 had relevant services but (82%) had no pathway or agreed initial management.

Conclusions

It appears to be common for no acute care pathway to exist for CRPS in NHS Trusts in England despite it being a domain in BOA national guidelines. The Royal College of Physicians guidelines also recommend integrated MDT care. Consequentially, BOA and Royal College of Physicians standards in acute CRPS management are not yet being followed in most acute NHS Trusts in England providing trauma care. Where there is a pathway agreed, it is rarely integrated and truly multidisciplinary.

Complex Regional Pain Syndrome Type 1: Diagnosis and Management

Diagnosis of Complex regional pain syndrome (CRPS) is made primarily on a clinical basis, and no specific test is known to confirm or exclude CRPS diagnosis. That is, there aren’t specific diagnostic tools and instrumental tests are made only for identifying an etiology at the basis of the CRPS. Numerous therapeutic methods have been introduced, but none have shown definitive results. When symptoms persist, patients experience permanent impairment and disability. Therefore, early recognition of CRPS, along with proper treatment, is important for minimizing permanent loss of function. As there is no gold standard test for CRPS, several clinical diagnostic criteria have been introduced and applied in various studies. However, to date, no formal or standardized diagnostic criteria for CRPS have been widely accepted. However, the Budapest diagnostic criteria have recently increased in popularity and are frequently used in scientific studies. The goal for management of CRPS is the return of normal limb function. No specific technique has been shown to prevent CRPS following surgery, but avoidance of prolonged immobilization may be important. Therefore, initiating early post-surgical rehabilitation, where possible, is important. A multidisciplinary approach would seem to be optimal, above all things objectives of physical and occupational therapy are fulfilled with combination pharmacotherapy due to provide pain relief to facilitate physical rehabilitation. Future research using large randomized controlled trials should focus on collecting strong evidence for the etiology of CRPS, testing pharmacological effects, and determining appropriate combination treatment strategies.

The Legal Doctrine on the Liability of Physicians in Medical Malpractice Lawsuits Involving Complex Regional Pain Syndrome

BACKGROUND

Complex regional pain syndrome (CRPS) involves severe pain and it is difficult to identify the exact cause or pathogenesis. Therefore, there are controversies regarding legal issues related to the establishment of damage in medical malpractice lawsuits involving CRPS. This study aimed to analyze malpractice lawsuits involving CRPS, which occurred after the disputed medical treatment, to provide information on the courts' opinion and characteristics of the cases.

METHODS

This study analyzed 23 lawsuit judgments involving CRPS that were sentenced from 2005 to 2015.

RESULTS

A total of 12 of the 23 cases were partially ruled in favor of the plaintiff. The average amount (KRW) claimed was 470,638,385 ± 860,634,092 (21,000,000 to 4,020,000,000), and that awarded was 72,906,843 ± 53,389,367 (15,000,000 to 181,080,803). Sixteen of the 23 cases had CRPS type I. In 11 of 23 cases, the site of the pain was located in the lower limb and in 14 cases there was no presence of trauma or event prior to medical treatment.

CONCLUSION

Nerve injury was the most frequent reason for taking responsibility in compensating damage in malpractice cases involving CRPS. Physicians should consider various possibilities of such complications in medical practices. It is important to identify and improve areas which need to be improved for patient safety through analyzing the lawsuit judgment cases.

Signs and Symptoms in 1,043 Patients with Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a complex pain disorder that can emerge after limb trauma or a lesion in the peripheral nervous system. Typical features include continuing pain, sensory, vasomotor, sudomotor, motor, and trophic changes as well as edema. These signs provide the basis of CRPS diagnosis. A detailed description of the signs, symptoms, and medical history of CRPS could potentially facilitate an earlier and more accurate diagnosis. The aim of this study was to provide such a description, on the basis of epidemiological measures, clinical presentation, and a thorough description of pain sensations. Some signs (eg, differences of skin temperature >1°C), which have been thought to be crucial for diagnosis, were less common than assumed. We identified 11 distinct etiological triggers, which cover more than 99% of the study participants. We developed a weighted score on the basis of the most decisive data, which achieved a sensitivity of .869 and a specificity of .829, compared with .819 and .679 for the Budapest criteria. The weighted diagnostic criteria may help to better aid in distinguishing CRPS from other pain disorders.

PERSPECTIVE

This article provides a retrospective epidemiological analysis of 1,043 CRPS patients compared with 421 patients with other pain disorders. The findings could potentially facilitate a more reliable and earlier diagnosis of CRPS, a better differentiation from other pain disorders, and ultimately in a more targeted and effective therapy.

Transcranial magnetic stimulation studies in complex regional pain syndrome type I: A review

The sensory and motor cortical representation corresponding to the affected limb is altered in patients with complex regional pain syndrome (CRPS). Transcranial magnetic stimulation (TMS) represents a useful non-invasive approach for studying cortical physiology. If delivered repetitively, TMS can also modulate cortical excitability and induce long-lasting neuroplastic changes. In this review, we performed a systematic search of all studies using TMS to explore cortical excitability/plasticity and repetitive TMS (rTMS) for the treatment of CRPS. Literature searches were conducted using PubMed and EMBASE. We identified 8 articles matching the inclusion criteria. One hundred fourteen patients (76 females and 38 males) were included in these studies. Most of them have applied TMS in order to physiologically characterize CRPS type I. Changes in motor cortex excitability and brain mapping have been reported in CRPS-I patients. Sensory and motor hyperexcitability are in the most studies bilateral and likely involve corresponding regions within the central nervous system rather than the entire hemisphere. Conversely, sensorimotor integration and plasticity were found to be normal in CRPS-I. TMS examinations also revealed that the nature of motor dysfunction in CRPS-I patients differs from that observed in patients with functional movement disorders, limb immobilization, or idiopathic dystonia. TMS studies may thus lead to the implementation of correct rehabilitation strategies in CRPS-I patients. Two studies have begun to therapeutically use rTMS. This non-invasive brain stimulation technique could have therapeutic utility in CRPS, but further well-designed studies are needed to corroborate initial findings.

Neurogenic Edema from Complex Regional Pain Syndrome Resulting in Fulminant Infection Necessitating Below Elbow Amputation

We report a case of severe upper extremity complex regional pain syndrome type 1 (CRPS-1) and neurogenic edema that ultimately led to a medically necessary below-elbow amputation. The patient presented with a history of remote bilateral carpal tunnel release complicated by debilitating and recalcitrant bilateral CRPS-1. Following years of severe neurogenic edema of the left upper extremity, the patient had full-thickness skin sloughing on the dorsum of her hand due to massive edema. This subsequently led to maggot infestation of the soft tissues of the left hand ultimately necessitating amputation. We present the case as an illustration of an extreme case of neurogenic edema, a potential physical manifestation of CRPS-1. The case presented discusses upper extremity amputation as an end treatment option for CRPS-1, though in this case amputation was primarily indicated secondary to medical necessity.

Hand lesion after arthroscopic rotator cuff repair: Association with complex regional pain syndrome

BACKGROUND

It is known that complex regional pain syndrome (CRPS) occurs after arthroscopic rotator cuff repair (ARCR); however, few studies have investigated this complication. Therefore, the purpose of the present study was to evaluate CRPS after ARCR.

METHODS

A total of 182 patients who underwent ARCR were enrolled in this study. The average age of patients was 62.8 ± 10.0 years, with an average follow-up period of 21.5 ± 38.1 months. CRPS criteria outlined by the Ministry of Health, Labor, and Welfare study team for CRPS in Japan (MHLWJ) and International Association for the Study of Pain (IASP 2005) were utilized for diagnosis. There are two rating systems for the "clinical purpose" and "research purpose" in both criteria, respectively. Clinical outcomes, including Japanese Orthopedic Association (JOA) and University of California, Los Angeles scores, were evaluated using univariate and multivariate analysis.

RESULTS

CRPS exclusively occurred in the hand of the operated limb, developing within 3 months of surgery. Two or more of the following symptoms were noted in patients with the hand lesion associated with CRPS: edema (93.4%), restricted range of motion (83.4%), hyperalgesia (30.1%), paridrosis (20.4%), and atrophic change (12.2%). Under these conditions, the incidences of CRPS were 24.2% (44/182) when evaluated by the MHLWJ rating system for the "clinical purpose;" 11% (22/182) by the MHLWJ rating system for the "research purpose;" 6% (11/182) by the IASP 2005 for the "clinical purpose;" and 0.5% (1/182) by the IASP 2005 for the "research purpose." Results of multivariate analysis demonstrated that "Function" in the JOA score was a risk factor for the development of CRPS after ARCR, when evaluated by a system for the "clinical purpose" of the MHLWJ.

CONCLUSION

Following ARCR, CRPS-induced hand lesions occur more frequently than is generally believed, thereby suggesting that its impact on surgical outcomes should be clarified in the future.

A mysterious case of complex regional pain syndrome in a 9-year-old girl

PURPOSE

To describe the clinical manifestation and the treatment of complex regional pain syndrome type II in childhood.

METHODS

Using information on the symptoms, diagnosis, rehabilitation and outcome of a young patient with complex regional pain syndrome type II.

RESULTS

A 9-year -old girl had severe pain in the region of the left foot, signs of a common fibular nerve entrapment, hyperalgesia not limited to the distribution of the injured nerve, weakness and temperature asymmetry unknown origin. She consulted few doctor's before she was given the right diagnosis of complex regional pain syndrome type II. Following the diagnosis the treatment started, it included intensive physiotherapy, electrical therapy and also supportive psychological therapy. Half a year later, the patient was free of the daily pain and returned to all physical activity without any restrictions.

CONCLUSIONS

The case report illustrates that peripheral nerve compression or injuries specifically, complex regional pain syndrome type II, should be taken into consideration when evaluating children with weakness and pain of the lower or upper limb. Implication of rehabilitation Raising the awareness of complex regional pain syndrome in the childhood is essential for an early diagnosis and appropriate treatment. The treatment options include early and adequate pain management inclusive electrical therapy and physiotherapy. Psychological therapy helps to avoid psychological stress reaction and the disease negative impact on the child's education and sports and the family social life.

Complex regional pain syndrome-up-to-date

Complex regional pain syndrome (CRPS) was described for the first time in the 19th century by Silas Weir Mitchell. After the exclusion of other causes, CRPS is characterised by a typical clinical constellation of pain, sensory, autonomic, motor, or trophic symptoms which can no longer be explained by the initial trauma. These symptoms spread distally and are not limited to innervation territories. If CRPS is not improved in the acute phase and becomes chronic, the visible symptoms change throughout because of the changing pathophysiology; the pain, however, remains. The diagnosis is primarily clinical, although in complex cases further technical examination mainly for exclusion of alternative diagnoses is warranted. In the initial phase, the pathophysiology is dominated by a posttraumatic inflammatory reaction by the activation of the innate and adaptive immune system. In particular, without adequate treatment, central nociceptive sensitization, reorganisation, and implicit learning processes develop, whereas the inflammation moderates. The main symptoms then include movement disorders, alternating skin temperature, sensory loss, hyperalgesia, and body perception disturbances. Psychological factors such as posttraumatic stress or pain-related fear may impact the course and the treatability of CRPS. The treatment should be ideally adjusted to the pathophysiology. Pharmacological treatment maybe particularly effective in acute stages and includes steroids, bisphosphonates, and dimethylsulfoxide cream. Common anti-neuropathic pain drugs can be recommended empirically. Intravenous long-term ketamine administration has shown efficacy in randomised controlled trials, but its repeated application is demanding and has side effects. Important components of the treatment include physio- and occupational therapy including behavioural therapy (eg, graded exposure in vivo and graded motor imaging). If psychosocial comorbidities exist, patients should be appropriately treated and supported. Invasive methods should only be used in specialised centres and in carefully evaluated cases. Considering these fundamentals, CRPS often remains a chronic pain disorder but the devastating cases should become rare.

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.

Effects of Glutathione on Mechanical Allodynia and Central Sensitization in Chronic Postischemic Pain Rats

Background

The chronic postischemia pain (CPIP) model is an animal model using ischemia/reperfusion injury that mimics the symptoms of complex regional pain syndrome type I. Glutathione (GSH) prevents ischemia/reperfusion injury by scavenging free radicals. We conducted this study to investigate the protective effect of GSH in CPIP rats via changes of mechanical allodynia and phospholyration of the N-methyl-D-aspartate receptor subunit GluN1.

Methods

We divided 45 rats into 5 groups: sham, CPIP, CPIP + GSH 100 mg/kg, CPIP + GSH 200 mg/kg, and CPIP + GSH 500 mg/kg. Rats in the sham and CPIP groups received normal saline and rats in the other groups received GSH at the designated doses thirty minutes prior to reperfusion. Withdrawal thresholds were evaluated before sugery as well as 1, 3, and 7 days after surgery. pGluN1 level in the spinal cord was also measured.

Results

GSH treated rats show a significant increase in the withdrawal thresholds of both hind paws as compared with the CPIP group dose-dependently. The expression of pGluN1 in the GSH treated rats significantly decreased as compared to the CPIP group (all P < 0.05).

Conclusion

These findings suggest that GSH inhibited the development of mechanical allodynia and central sensitization in CPIP rats.

Effects of Linearly Polarized Near-Infrared Irradiation Near the Stellate Ganglion Region on Pain and Heart Rate Variability in Patients with Neuropathic Pain

Background

Neuropathic pain associated with sympathetic overactivity can be effectively relieved by light irradiating the region near stellate ganglion (SGI), applied as an alternative to a conventional sympathetic blockade. The clinical effect of SGI on heart rate variability (HRV) and its association with pain outcomes require investigation.

Objective

This study attempted to identify the effects of SGI on pain outcomes and HRV indices and to determine the association between pain and HRV outcomes.

Design

A prospective double-blind, randomized study.

Setting

An outpatient pain medicine clinic.

Subjects and Methods

A total of 44 patients were enrolled and randomized into the experimental group ( n = 22) and control group ( n = 22). The experimental group received 12 sessions (twice weekly) of standard SGI, whereas the control group received the same protocol with sham irradiation. Pain and HRV were measured before and after each irradiation session. All outcome measures used in the first- and second-half treatment courses were analyzed.

Results

Pain and HRV outcome measures of the experimental group significantly improved after SGI when compared with the control group in both courses. Considering time and frequency domains, the changes in HRV in the second-half treatment course exceeded those in the first-half treatment course. Pain was significantly associated with postirradiated HRV indices ( P < 0.001).

Conclusions

Twelve sessions of SGI exerted time-dependent positive effects on pain and sympathovagal imbalance. HRV outcomes, including time and frequency domains, were an independent indicator of the clinical efficiency of SGI for treating pain in patients with neuropathic pain.

Fluctuating residual limb volume accommodated with an adjustable, modular socket design: A novel case report

BACKGROUND

This novel case report describes the problems of prescribing a prosthetic socket in a left transfemoral amputee secondary to chronic patellofemoral instability compounded by complex regional pain syndrome. Case Description and Methods: Following the amputation, complex regional pain syndrome symptoms recurred in the residual limb, presenting mainly with oedema. Due to extreme daily volume fluctuations of the residual limb, a conventional, laminated thermoplastic socket fitting was not feasible. Findings and Outcomes: An adjustable, modular socket design was trialled. The residual limb volume fluctuations were accommodated within the socket. Amputee rehabilitation could be continued, and the rehabilitation goals were achieved. The patient was able to wear the prosthesis for 8 h daily and to walk unaided indoors and outdoors.

CONCLUSION

An adjustable, modular socket design accommodated the daily residual limb volume fluctuations and provided a successful outcome in this case. It demonstrates the complexities of socket fitting and design with volume fluctuations. Clinical relevance Ongoing complex regional pain syndrome symptoms within the residual limb can lead to fitting difficulties in a conventional, laminated thermoplastic socket due to volume fluctuations. An adjustable, modular socket design can accommodate this and provide a successful outcome.

Physiology of Pain

Acutely ill patients are challenging to frontline nurses because they frequently also have multiple chronic conditions. This article empowers all nurses to develop a foundational understanding of the physiology of acute and chronic pain. The skills, knowledge, and attitude to care for patients experiencing pain are a legal and ethical responsibility of all nurses. This article discusses the physiology of pain to include the neuronal receptors that respond to various painful stimuli, substances that stimulate nociceptors, the nerve pathways, modulation of the perception of pain, and acute verses chronic physiologic changes.

Tratamiento quirúrgico de los síndromes dolorosos regionales complejos tipo II y utilidad de la monitorización neurofisiológica intraoperatoria

El propósito de esta revisión era presentar las bases bilógicas y fisiopatológicas de la formación de neuromas como causa de los síndromes dolorosos regional (SDRC) tipo II y el uso de la monitorización neurofisiológica intraoperatoria en el tratamiento de los SDRC tipo II secundarios a neuromas en continuidad y en nervios adheridos en cicatrices tras cirugías previas.

Effects of Simvastatin Beyond Dyslipidemia: Exploring Its Antinociceptive Action in an Animal Model of Complex Regional Pain Syndrome-Type I

Simvastatin is a lipid-lowering agent that blocks the production of cholesterol through inhibition of 3-hydroxy-methyl-glutaryl coenzyme A (HMG-CoA) reductase. In addition, recent evidence has suggested its anti-inflammatory and antinociceptive actions during inflammatory and pain disorders. Herein, we investigated the effects of simvastatin in an animal model of complex regional pain syndrome-type I, and its underlying mechanisms. Chronic post-ischemia pain (CPIP) was induced by ischemia and reperfusion (IR) injury of the left hind paw. Our findings showed that simvastatin inhibited mechanical hyperalgesia induced by CPIP model in single and repeated treatment schedules, respectively; however simvastatin did not alter inflammatory signs during CPIP model. The mechanisms underlying those actions are related to modulation of transient receptor potential (TRP) channels, especially TRMP8. Moreover, simvastatin oral treatment was able to reduce the nociception induced by acidified saline [an acid-sensing ion channels (ASICs) activator] and bradykinin (BK) stimulus, but not by TRPA1, TRPV1 or prostaglandin-E2 (PGE2). Relevantly, the antinociceptive effects of simvastatin did not seem to be associated with modulation of the descending pain circuits, especially noradrenergic, serotoninergic and dopaminergic systems. These results indicate that simvastatin consistently inhibits mechanical hyperalgesia during neuropathic and inflammatory disorders, possibly by modulating the ascending pain signaling (TRPM8/ASIC/BK pathways expressed in the primary sensory neuron). Thus, simvastatin open-up new standpoint in the development of innovative analgesic drugs for treatment of persistent pain, including CRPS-I.

Bone scintigraphy in patients with pain

Nuclear medicine imaging is widely used in pain medicine. Low back pain is commonly encountered by physicians, with its prevalence from 49% to 70%. Computed tomography (CT) or magnetic resonance imaging (MRI) are usually used to evaluate the cause of low back pain, however, these findings from these scans could also be observed in asymptomatic patients. Bone scintigraphy has an additional value in patients with low back pain. Complex regional pain syndrome (CRPS) is defined as a painful disorder of the extremities, which is characterized by sensory, autonomic, vasomotor, and trophic disturbances. To assist the diagnosis of CRPS, three-phase bone scintigraphy is thought to be superior compared to other modalities, and could be used to rule out CRPS due to its high specificity. Studies regarding the effect of bone scintigraphy in patients with extremity pain have not been widely conducted. Ultrasound, CT and MRI are widely used imaging modalities for evaluating extremity pain. However, SPECT/CT has an additional role in assessing pain in the extremities.

Orofacial complex regional pain syndrome: pathophysiologic mechanisms and functional MRI

Complex regional pain syndrome (CRPS) is one of the most challenging chronic pain conditions and is characterized by burning pain, allodynia, hyperalgesia, autonomic changes, trophic changes, edema, and functional loss involving mainly the extremities. Until recently, very few reports have been published concerning CRPS involving the orofacial area. We report on a 50-year-old female patient who presented with unbearable pain in all of her teeth and hypersensitivity of the facial skin. She also reported intractable pain in both extremities accompanied by temperature changes and orofacial pain that increased when the other pains were aggravated. In the case of CRPS with trigeminal neuropathic pain, protocols for proper diagnosis and prompt treatment have yet to be established in academia or in the clinical field. We performed functional magnetic resonance imaging for a thorough analysis of the cortical representation of the affected orofacial area immediately before and immediately after isolated light stimulus of the affected hand and foot and concluded that CRPS can be correlated with trigeminal neuropathy in the orofacial area. Furthermore, the patient was treated with carbamazepine administration and stellate ganglion block, which can result in a rapid improvement of pain in the trigeminal region.

Complex regional pain syndrome in children: a systematic review of clinical features and movement disorders

Aim: To ascertain clinical features of complex regional pain syndrome (CRPS) in children with a focus on movement disorders. Methods: all publications with original data on children with CRPS were assessed. Data were tabulated and descriptive statistics were applied. Results: One population-based study and nine clinic-based studies provided data on demographic and clinical characteristics of childhood CRPS. Mean age of onset was 12.5 years and 85% of patients were females (risk ratio: 1.70; 95% CI: 1.54−1.88). History of trauma in 71% and the lower limbs were affected in 75% of patients. A secondary site involvement was present in 15%. Movement disorders and dystonia were reported in 30% of children. Conclusion: Majority of cases of CRPS in children are females with mean age of 12.5 years. Movement disorders (mainly dystonia) affect at least one in three children with CRPS.

Systemic Intravenous Lidocaine for the Treatment of Complex Regional Pain Syndrome: A Case Report and Literature Review

Complex regional pain syndrome (CRPS) was described in 1864 by Mitchell et al as a condition characterized by many unique symptoms. Although symptoms may differ from patient to patient, the most common complaints are painful swelling in upper or lower extremities or changes in the skin. CRPS has been given many different names since it was first mentioned in the literature in 1851. The most common alternative names include causalgia, aglodystrophy, and sympathetic dystrophy syndrome. This condition is generally diagnosed in older adults because of trauma, nerve damage, and coronary artery disease; however, there are cases of CRPS affecting the pediatric and young adult population. The fourth edition of the diagnostic and treatment guidelines of CRPS published by Harden et al in 2013 suggest many different pharmacologic treatment options for these patients. Intravenous lidocaine is used to block the sodium channels in neuronal membranes, thus stopping initiation and conduction of impulses associated with neuropathic and inflammatory pain. The use of regional intravenous lidocaine (by applying a tourniquet on the affected extremity) has been well-documented in the literature with a successful decrease in pain symptoms. A unique case of the use of systemic intravenous lidocaine will be presented.

Multicenter study on the asymmetry of skin temperature in complex regional pain syndrome: An examination of temperature distribution and symptom duration

According to the International Association for the Study of Pain (IASP) and American Medical Association (AMA), the diagnostic criteria for complex regional pain syndrome (CRPS) require the presence of skin temperature asymmetry. In CRPS, it is generally accepted that the temperature of skin of affected limbs changes from warm to cold; however, in our clinical practice, we have experienced many cases with different thermographic characteristics. Therefore, we conducted a retrospective multicenter study that examined the distribution of skin temperature in patients with CRPS and skin temperature asymmetry versus symptom duration.Patients diagnosed with type 1 or 2 CRPS were recruited. After confirming CRPS according to the IASP diagnostic criteria, infrared thermographic images were evaluated for skin temperature differences (ΔT) between the affected and unaffected limbs.A total of 296 patients with CRPS were included in this study. The median duration of symptoms was 6 months and the mean ± standard deviation of ΔT was -0.72 ± 1.65°C. A skin temperature difference between bilateral limbs (|ΔT|) of 1°C or less was seen in 131 patients (44.3%); thus, these 131 patients did not meet the IASP criteria for CRPS. Further, cool skin temperature was not observed in 88 patients (29.7%), meaning that these patients did not meet the AMA criteria for CRPS. There was no correlation between the symptom duration and ΔT (Spearman's rho = -0.075, P = 0.196) and there was no significant difference in the average ΔT among the 4 symptom duration groups (0-3 months, 4-6 months, 7-12 months, >12 months, P = 0.08).In conclusion, a considerable proportion of the patients that participated in this study did not meet the thermal criteria set forth by the IASP and AMA. Further, there was no correlation between symptom duration and skin temperature difference.

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.

Relationship Between HbA1c and Complex Regional Pain Syndrome in Stroke Patients With Type 2 Diabetes Mellitus

Objective

To investigate the relationship between glycosylated hemoglobin A (HbA1c) and complex regional pain syndrome (CRPS) in stroke patients with type 2 diabetes mellitus (T2DM).

Methods

A retrospective chart review was performed of stroke patients from January 2012 to December 2013. We reviewed 331 patients and included 200 in the analysis. We divided them into CRPS and non-CRPS groups and compared them by age, gender, stroke lesion, cause of stroke, duration of T2DM, HbA1c (%), National Institutes of Health Stroke Scale score, affected shoulder flexor muscle strength, Fugl-Meyer Assessment score, motricity index, Functional Independence Measure, Korean version of Modified Barthel Index, blood glucose level on admission day, duration from stroke onset to HbA1c check, and duration from stroke onset to three-phase bone scan for CRPS diagnosis. Thereafter, we classified the patients into five groups by HbA1c level (group 1, 5.0%–5.9%; group 2, 6.0%–6.9%; group 3, 7.0%–7.9%; group 4, 8.0%–8.9%; and group 5, 9.0%–9.9%) and we investigated the difference in CRPS prevalence between the two groups.

Results

Of the 200 patients, 108 were in the CRPS group and 92 were in the non-CRPS group. There were significant differences in HbA1c (p<0.05) between the two groups but no significant differences in any other factors. Across the five HbA1c groups, there were significant differences in CRPS prevalence (p<0.01); specifically, it increased as HbA1c increased.

Conclusion

This study suggests that higher HbA1c relates to higher CRPS prevalence and thus that uncontrolled blood glucose can affect CRPS occurrence in stroke patients with diabetes.

The Relation Between Reflex Sympathetic Dystrophy Syndrome and Trauma Severity in Patients With Distal Tibia Fracture

BACKGROUND

Reflex sympathetic dystrophy (RSD) syndrome is a multifactorial disorder with clinical features of neurogenic inflammation that causes hypersensitivity to pain or severe allodynia as well as blood flow problems, swelling, skin discoloration and maladaptive neuroplasticity due to vasomotor disorders. Patients with major trauma are prone to homeostasis leading to inflammatory response syndrome and multiple organ distress syndrome. Several studies have investigated the etiology of this condition, but the cause remains unknown. The role of associated factors such as the limb immobilization technique and genetics has been reported in the development of this complication, but, so far, there is no information regarding the effect of trauma severity on the risk of RSD occurrence.

OBJECTIVES

Given the importance of diagnosing and treating this condition, we aimed to study the effect of trauma severity on the prevalence of RSD.

PATIENTS AND METHODS

In this cross-sectional study, we examined patients with distal tibial fracture who visited Rasht Poursina hospital from 2010 to 2013. Exclusion criteria included associated fractures, underlying musculoskeletal diseases and mental and cognitive problems. To assess the severity of the initial injury in patients, the Hannover Fracture Scale 98 (HFS98) scoring checklist was used. The diagnosis of RSD was made on the basis of the IASP criterion. Demographic data, HFS98 scores, and information regarding RSD prevalence were analyzed using SPSS version 20. The Mann Whitney U nonparametric test was used for variables that were not normally distributed; the chi-square test was used to compare the qualitative variables.

RESULTS

Among the 488 patients, 292 (59.83%) were male. The mean age of the study population was 44 ± 9.82 years. During the 6-month follow-up, RSD occurred in 45 patients, of whom 28 (62.22%) were female and 17 (37.77%) were male; there was thus a significant difference in the prevalence of RSD in terms of gender (P = 0.00; chi square test). The mean HFS98 score in patients without and with RSD was 3.081 ± 4.083 and 4.080 ± 4.622, respectively, and the difference was not statistically significant (P = 0.363; Mann Whitney U test). Analyses of the eight items of HFS98 shows that local circulation in patients with RSD is significantly better than that in patients without RDS (0.683 ± 0.822 vs. 0.528 ± 0.629, respectively). Statistical analysis showed that the odds ratio for RSD for patients with HFS95 score > 0 was 1.079 (confidence interval [CI]: 0.898 - 1.333). Moreover, the odds ratio for RSD was 1.100 (CI: 795 - 1.531) in patients with an injury severity score higher than the calculated mean score in patients without RSD (> 4.083).

CONCLUSIONS

The results suggest no significant relationship between the severity of injury and risk of RSD occurrence, although the mean injury severity score was higher in patients with RSD than in those without RSD in this study population. The lower score of local circulation in patients with RSD than in those without RSD is a statistically significant finding and can be attributed to changes in the antioxidant levels at the injury site, which is one of the main mechanisms for the onset of RSD. Wound contamination was also justifiably higher in patients with RSD, although the difference was not statistically significant. In summary, the severity of injury alone cannot be a determining factor for predicting the probability of RSD.