Recurrent postoperative CRPS I in patients with abnormal preoperative sympathetic function

Upregulation of delta opioid receptor by meningeal interleukin-10 prevents relapsing pain

Chronic pain often includes periods of transient amelioration and even remission that alternate with severe relapsing pain. While most research on chronic pain has focused on pain development and maintenance, there is a critical unmet need to better understand the mechanisms that underlie pain remission and relapse. We found that interleukin (IL)-10, a pain resolving cytokine, is produced by resident macrophages in the spinal meninges during remission from pain and signaled to IL-10 receptor-expressing sensory neurons. Using unbiased RNA-sequencing, we identified that IL-10 upregulated expression and antinociceptive activity of δ-opioid receptor (δOR) in the dorsal root ganglion. Genetic or pharmacological inhibition of either IL-10 signaling or δOR triggered relapsing pain. Overall, our findings, from electrophysiology, genetic manipulation, flow cytometry, pharmacology, and behavioral approaches, indicate that remission of pain is not simply a return to the naïve state. Instead, remission is an adapted homeostatic state associated with lasting pain vulnerability resulting from persisting neuroimmune interactions within the nociceptive system. Broadly, this sheds light on the elusive mechanisms underlying recurrence a common aspect across various chronic pain conditions.

The Evidence for Perioperative Anesthetic Techniques in the Prevention of New-Onset or Recurrent Complex Regional Pain Syndrome in Hand Surgery

Complex regional pain syndrome (CRPS) is a multifaceted condition characterized by chronic neuropathic pain, allodynia, and hyperalgesia. The incidence of CRPS postoperatively is alarmingly high, particularly following carpal tunnel surgeries, Dupuytren's fasciectomy, and repairs of wrist and hand fractures, with recurrence rates soaring in individuals with a history of CRPS. Despite extensive research, the management of CRPS remains complicated, highlighting the urgent need for effective prevention strategies. This scoping review aimed to consolidate current evidence surrounding the efficacy of perioperative anesthetic techniques in preventing new-onset or recurrent CRPS, focusing on the application of various anesthetic interventions. Through a comprehensive literature search, eight articles were identified, discussing a spectrum of techniques, including wide awake local anesthesia no tourniquet (WALANT) and various regional blockade methods. This review revealed that the WALANT technique, with its simplicity and lower costs, exhibited promising results in preventing CRPS. Conversely, techniques involving intravenous regional and axillary plexus blocks showed variable efficacy, necessitating further investigation. The scarcity of high-quality evidence underscores the critical need for meticulously designed, large-scale randomized controlled trials to validate these findings and explore the potential of stellate ganglion block in the prevention of recurrent CRPS.

Chiropractic Care of a Patient With Complex Regional Pain Syndrome Type 1 (CRPS-1): A Case Report

Objective

The purpose of this case report is to describe the evaluation and treatment of a patient presenting with left upper extremity pain and neck pain after a slip and fall.

Clinical Features

A 56-year-old woman sustained a left distal radius fracture secondary to a slip-and-fall accident. She was placed in a cast for 6 weeks, and after the removal of her cast she developed excruciating left forearm, wrist, hand, and finger pain. The patient was diagnosed with complex regional pain syndrome type 1 utilizing the modified (Budapest) International Association for the Study of Pain criteria.

Intervention and Outcome

The patient did not respond positively to initial management, which included the application of a cast after closed reduction of the distal radius fracture, 8 weeks of physical/occupational therapy, and the use of a brace which kept her left wrist, hand, and fingers in a flexed position. Subsequently, the patient presented to the University of Bridgeport College of Chiropractic outpatient clinic, where she was evaluated and treated. She received a total of 36 chiropractic treatments between her initial office visit in January 2018 and the follow-up in June 2018. The patient reported and demonstrated amelioration of her presenting complaints, decreased pain, increased ranges of motion, and increased function.

Conclusion

This case report underscores the importance of a rapid, accurate, initial diagnosis of complex regional pain syndrome type 1, during the acute (warm) stage.

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.

Subliminal (latent) processing of pain and its evolution to conscious awareness

By unconscious or covert processing of pain we refer to nascent interactions that affect the eventual deliverance of pain awareness. Thus, internal processes (viz., repeated nociceptive events, inflammatory kindling, reorganization of brain networks, genetic) or external processes (viz., environment, socioeconomic levels, modulation of epigenetic status) contribute to enhancing or inhibiting the presentation of pain awareness. Here we put forward the notion that for many patients, ongoing sub-conscious changes in brain function are significant players in the eventual manifestation of chronic pain. In this review, we provide clinical examples of nascent or what we term pre-pain processes and the neurobiological mechanisms of how these changes may contribute to pain, but also potential opportunities to define the process for early therapeutic interventions.

Microvascular Response in Patients with Complex Regional Pain Syndrome as Measured by Laser Doppler Imaging

Objectives

Our aim was to investigate the hypothesis that microvascular dysfunction occurs in patients with CRPS. Specifically, whether there were functional differences in either deeper cutaneous blood vessels or more superficial nutritive vessels between the affected and unaffected limb in patients with CRPS, and between CRPS patients and healthy control subjects.

Methods

Twenty‐two patients with CRPS (five male; mean age 45 years; eight upper limb involvement, 14 lower limb) and 23 healthy control subjects (one male; 43 years) were recruited. Microvascular flow at affected and unaffected contralateral sites was measured, following local heating, using laser Doppler imaging (red/green wavelengths). Corresponding sites were imaged in healthy controls. Maximum flux level and area under the curve (first 20 scans, AUC20) were measured.

Results

Vasodilator responses to heat were similar in affected and unaffected limbs, and in healthy controls. For example, median (IQR) “red” AUC20 in CRPS was 138.6 (120.0–152.9)% change from baseline in affected limb and 135.0 (120.7–166.8)% in unaffected limb, and (in healthy controls) 133.1 (117.2–145.9)% and 139.1% (126.0–162.1) in limb 1 and 2.

Conclusions

We found no impairment of vasodilation in cutaneous microvessels in CRPS. The vasomotor changes in CRPS may relate to larger vessel dysfunction.

Abductor Digiti Minimi Flap for Vascularized Coverage in the Surgical Management of Complex Regional Pain Syndrome Following Carpal Tunnel Release

BACKGROUND

The development of Complex Regional Pain Syndrome (CRPS) represents a potentially devastating complication following carpal tunnel release. In the presence of a suspected incomplete release of the transverse carpal ligament or direct injury to the median nerve, neurolysis as well as nerve coverage to prevent recurrent scar has been shown to be effective.

METHODS

Retrospective chart review and telephone interview was conducted for patients who underwent abductor digiti minimi flap coverage and neurolysis of the median nerve for CRPS following carpal tunnel release.

RESULTS

Fourteen wrists in 12 patients were reviewed. Mean patient age was 64 years (range, 49-83 years), and the mean follow-up was 44 months. Carpal tunnel outcome instrument scores were 47.4 ± 6.8 preoperatively and 27.1 ± 10.6 at follow-up ( P < .001). Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores at follow-up were 29.4 ± 26. No significant postoperative complications were identified.

CONCLUSIONS

The abductor digiti minimi flap is a reliable option with minimal donor site morbidity. It provides predictable coverage when treating CRPS following carpal tunnel syndrome.

The risk of pain syndrome affecting a previously non-painful limb following trauma or surgery in patients with a history of complex regional pain syndrome

BACKGROUND AND PURPOSE

Complex regional pain syndrome (CRPS) is a challenging complication after surgery or trauma. This study sought to determine the incidence of CRPS after a second inciting event in a previously unaffected extremity in patients with a history of an ongoing CRPS diagnosis in another extremity.

METHODS

A retrospective review identified patients with CRPS seen in clinic over a 20-month period. The incidence of CRPS after subsequent surgery or injury in a previous unaffected extremity was determined and compared to an average incidence reported in the literature.

RESULTS

Ninety-three patients had a diagnosis of primary CRPS. Nineteen (20.4%) developed CRPS in one or more additional extremity compared to the incidence of 23.4 per 100,000 (0.0234%) in the literature (odds ratio 1069.6, p<0.0001, 95% CI 562.0-2035.7). Twenty patients had a documented secondary injury or surgery in a second extremity. Fifteen (75%) developed secondary CRPS compared to a CRPS incidence rate of 6.4% following distal radius fracture, as determined by literature review (odds ratio 11.7, p<0.001, 95% CI 5.9-23.2).

CONCLUSIONS

These result suggest that patients with a history of CRPS are more likely to develop secondary CRPS compared to the rates reported in the literature among the general population.

IMPLICATIONS

Patients with a history of CRPS should be counselled that they may be at risk for developing secondary CRPS if they undergo surgery or sustain trauma to another extremity.

Perioperative management for patients with complex regional pain syndrome

SUMMARY Our knowledge of complex regional pain syndrome extends from the time of the American Civil War until today. Traumatic or surgical insults can be the precipitating factors in normal patients and can therefore be significant in the exacerbation of the condition. Complex regional pain syndrome patients complain of continuing pain that is disproportionate in severity to the inciting event. The pain is usually accompanied by sensory symptoms, such as allodynia or hyperalgesia, and vasomotor changes, such as changes in color or temperature. There has been increasing research on predicting the development of postoperative complex regional pain syndrome and its prevention. Management includes sympathetic blockades, spinal cord stimulation and medications (such as anticonvulsants, antidepressants, local anesthetics, NMDA antagonists and α-2-adrenergic agonists). In the last few years, several newer medications and supplements to prevent and treat the condition have been studied.

Free flap transfer for complex regional pain syndrome type II

A patient with complex regional pain syndrome type II was successfully treated using free anterolateral thigh flap transfer with digital nerve coaptation to the cutaneous nerve of the flap. Release of the scarred tissue and soft tissue coverage with targeted sensory nerve coaptation were useful in relieving severe pain.

Pathophysiology of the spreading of complex regional pain syndrome revisited: a case report

OBJECTIVE

  To determine if there is a relationship in our patient developing complex regional pain syndrome from a jellyfish and its subsequent spread to the contralateral side.

METHODS

  Data bases were searched using PubMed and Ovid. Keywords searched include "complex regional pain syndrome,""jelly fish," and "pathophysiology."

RESULTS

  This patient was successfully treated with a spinal cord stimulator implantation with bilateral lead placement at thoracic spine (T9) stimulating her lower extremities in addition to the leads that had already been placed in her cervical spine for her upper extremities.

CONCLUSION

  Definite knowledge of the pathophysiology of complex regional pain syndrome would allow better identification of risk factors for the development of this condition after trauma. This patient is at higher risk of developing complex regional pain syndrome and should avoid surgeries (such as knee and wrist surgeries) and high risk physical activities.

Sympathetic dysfunction in long-term complex regional pain syndrome

OBJECTIVE

Malfunction of the sympathetic nervous system (SNS) is common in early complex regional pain syndrome type I (CRPS I). This study was designed to evaluate the function of the SNS in patients with chronic CRPS I and to correlate the obtained data with hand function measurements.

MATERIALS AND METHODS

Thirty-two patients of both the sexes in whom the diagnosis of CRPS I of the upper extremity had been established for at least 3 years before they were included in the study. Besides a hand outcomes questionnaire [Michigan Hand Outcome Questionnaire, (MHQ)] the patients underwent a standardized testing of the peripheral sympathetic nervous system (pSNS) using laser Doppler flowmetry (LDF).

RESULTS

Mean time since initial diagnosis was 4.6+/-2.1 years. The mean MHQ score of the affected limb was 57.3+/-17 compared with 69.4+/-13.7 for the unaffected hand (P=0.002). Twenty patients (62.5%) still demonstrated pathologic results regarding the pSNS function (mean sympathetic reflex 0.18+/-0.11, normal range>0.38). We found no statistically significant correlation between pSNS function either with the clinical outcome as measured by MHQ (r=0.246; P=0.175), or with the level of pain (r=0.132; P=0.473).

CONCLUSIONS

Even 5 years after the diagnosis of CRPS I of the upper extremity we detected significant impairments of the pSNS in nearly two thirds of our patients. Patients still have pain and present with a significant deterioration of their hand function in comparison with the not affected hand. In our study we could not identify any correlation between pSNS function and clinical outcome as measured by MHQ.

Lower extremity complex regional pain syndrome: long-term outcome after surgical treatment of peripheral pain generators

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

CRPS of the upper or lower extremity: surgical treatment outcomes

The hypothesis is explored that CRPS I (the "new" RSD) persists due to undiagnosed injured joint afferents, and/or cutaneous neuromas, and/or nerve compressions, and is, therefore, a misdiagnosed form of CRPS II (the "new" causalgia). An IRB-approved, retrospective chart review on a series of 100 consecutive patients with "RSD" identified 40 upper and 30 lower extremity patients for surgery based upon their history, physical examination, neurosensory testing, and nerve blocks. Based upon decreased pain medication usage and recovery of function, outcome in the upper extremity, at a mean of 27.9 months follow-up (range of 9 to 81 months), gave results that were excellent in 40% (16 of 40 patients), good in 40% (16 of 40 patients) and failure 20% (8 of 40 patients). In the lower extremity, at a mean of 23.0 months follow-up (range of 9 to 69 months) the results were excellent in 47% (14 of 30 patients), good in 33% (10 of 30 patients) and failure 20% (6 of 30 patients). It is concluded that most patients referred with a diagnosis of CRPS I have continuing pain input from injured joint or cutaneous afferents, and/or nerve compressions, and, therefore, similar to a patient with CRPS II, they can be treated successfully with an appropriate peripheral nerve surgical strategy.