Causalgia: A Review of Nerve Resection, Amputation, Immunotherapy, and Amputated Limb CRPS II Pathology.

BACKGROUND: Causalgia and complex regional pain syndrome (CRPS) type II with nerve injury can be difficult to treat. Surgical peripheral nerve denervation for causalgia has been largely abandoned by pain clinicians because of a perception that this may aggravate a central component (anesthesia dolorosa). METHODS: We selectively searched Pubmed, Cochrane, MEDLINE, EMBASE, CINAHL Plus, and Scopus from 1947 for articles, books, and book chapters for evidence of surgical treatments (nerve resection and amputation) and treatment related to autoimmunity and immune deficiency with CRPS. RESULTS: Reviews were found for the treatment of causalgia or CRPS type II (n = 6), causalgia relieved by nerve resection (n = 6), and causalgia and CRPS II treated by amputation (n = 8). Twelve reports were found of autoimmunity with CRPS, one paper of these on associated immune deficiency and autoimmunity, and two were chosen for discussion regarding treatment with immunoglobulin and one by plasma exchange. We document a report of a detailed and unique pathological examination of a CRPS type II affected amputated limb and related successful treatment with immunoglobulin. CONCLUSIONS: Nerve resection, with grafting, and relocation may relieve uncomplicated causalgia and CRPS type II in some patients in the long term. However, an unrecognized and treatable immunological condition may underly some CRPS II cases and can lead to the ultimate failure of surgical treatments.

Causalgia: a military pain syndrome.

Causalgia, officially known as complex regional pain syndrome type II, is a pain syndrome characterized by severe burning pain, motor and sensory dysfunction, and changes in skin color and temperature sensation distal to an injured peripheral nerve. The pain syndrome primarily tends to affect combat soldiers after they sustain wartime injuries from blasts and gunshots. Here, the authors provide a historical narrative that showcases the critical contributions of military physicians to our understanding of causalgia and to the field of peripheral nerve neurosurgery as a whole.

The Tourniquet Ischemia Test in the Diagnosis of Complex Regional Pain Syndrome.

BACKGROUND: The tourniquet ischemia test (IT) is a hitherto rarely used tool for the diagnostic work-up of patients with suspected complex regional pain syndrome (CRPS). This analysis aims to determine the sensitivity and specificity of this test, and elucidate factors that can influence the test result. METHODS: Consecutive data on clinical presentation, results of the IT and other diagnostic tests, and clinical characteristics were analyzed from patients presenting at our autonomic laboratory between 2000 and 2011. IT results were compared with the final clinical diagnosis at discharge, and statistical analysis was performed to determine specificity, sensitivity, and positive and negative predictive values of the IT. RESULTS: A total of 78 patients were assessed. IT results were positive (≥50% reduction in pain during ischemia) in 26 cases and negative in 52 cases. CRPS was the final diagnosis in 45 cases, and in 33 cases, a different diagnosis was made. This results in a test sensitivity of 49% and a specificity of 88%, with a positive predictive value of 85% and a negative predictive value of 56%. Age, sex, the type and stage of CRPS, and the affected extremity did not influence the test result in a statistically significant manner. Specificity worsened to 76% if any pain reduction was rated as a positive test result. CONCLUSIONS: A positive tourniquet IT has a high positive predictive value for the diagnosis of CRPS. It is thus useful as a confirmatory assay in patients with suspected CRPS. Low sensitivity rules out its use as a screening test. SIGNIFICANCE: This study retrospectively analyzed the clinical significance of the tourniquet IT that was routinely used in patients with suspected CRPS. It showed that a positive IT result is useful as a confirmatory assay in patients fulfilling the clinical criteria.

Peripheral Nerve Stimulation for the 21st Century: Sural, Superficial Peroneal, and Tibial Nerves.

OBJECTIVE: Peripheral nerve stimulation (PNS) of the lower extremity has progressed significantly over the last decade. From the proof of concept that ultrasound-guided, percutaneous implantation was possible to advances in waveforms, the field has been rapidly evolving. While most nerves in the lower extremity can be PNS targets, consideration must be given to the ergonomics of pulse generator placement, patient comfort, and avoidance of lead migration. For this paper, we examine some of the conditions amenable to lower extremity PNS, review the evidence and history behind PNS for these conditions, and describe approaches for the tibial, sural, and superficial peroneal nerves. METHODS: A literature search was conducted using PubMed. Search terms used were "peripheral nerve stimulation," "lower extremity entrapment neuropathies," "sural nerve," "superficial peroneal nerve," "tibial nerve," and "tarsal tunnel syndrome." Emphasis was placed on randomized controlled studies, anatomical dissections, and comprehensive review articles. Approaches to nerves and ultrasound images were based on anecdotal PNS cases from an experienced implanter (SP). CONCLUSIONS: The development of ultrasound as a viable method of image guidance for percutaneous peripheral nerve stimulation has led to an exponential growth in the field. Lower extremity percutaneous lead placement is both feasible and an appropriate treatment modality for certain pain conditions.

Effectiveness and Safety of Dorsal Root Ganglion Stimulation for the Treatment of Chronic Pain: A Pooled Analysis.

INTRODUCTION: Since it became available in the mid-2010s, dorsal root ganglion (DRG) stimulation has become part of the armamentarium to treat chronic pain. To date, one randomized controlled trial, and several studies of moderate sample size and various etiologies have been published on this topic. We conducted a pooled analysis to investigate the generalizability of individual studies and to identify differences in outcome between chronic pain etiologic subgroups and/or pain location. MATERIALS AND METHODS: One prospective, randomized comparative trial and six prospective, single-arm, observational studies were identified that met pre-defined acceptance criteria. Pain scores and patient-reported outcome (PRO) measures were weighted by study sample sizes and pooled. Safety data are reported in aggregate form. RESULTS: Our analysis included 217 patients with a permanent implant at 12-month follow-up. Analysis of pooled data showed an overall weighted mean pain score of 3.4, with 63% of patients reporting ≥50% pain relief. Effectiveness sub-analyses in CRPS-I, causalgia, and back pain resulted in a mean reduction in pain intensity of 4.9, 4.6, and 3.9 points, respectively. Our pooled analysis showed a pain score for primary affected region ranging from 1.7 (groin) to 3.0 (buttocks) and responder rates of 80% for foot and groin, 75% for leg, and 70% for back. A substantial improvement in all PROs was observed at 12 months. The most commonly reported procedural or device complications were pain at the IPG pocket site, lead fracture, lead migration, and infection. CONCLUSIONS: DRG stimulation is an effective and safe therapy for various etiologies of chronic pain.

Complex regional pain syndrome: a narrative review for the practising clinician.

Complex regional pain syndrome (CRPS) is a life-altering condition that usually affects the extremities after a trauma or nerve injury. The physiologic changes that occur as a result of the inciting injury are complex, as the name of the syndrome implies. The pain and disability associated with CRPS often lead to psychological co-morbidities that create a vicious cycle of pain, isolation, and depression. We review recent developments in the understanding of CRPS and advancements in management of this syndrome. Further research in targeting specific mechanisms involved in the pathophysiology of CRPS should lead to prevention of this condition.

The Effect of Ketamine Infusion in the Treatment of Complex Regional Pain Syndrome: a Systemic Review and Meta-analysis.

PURPOSE OF REVIEW: Complex regional pain syndrome (CRPS) is a painful debilitating neurological condition that accounts for approximately 1.2% of adult chronic pain population. Ketamine, an NMDA receptor antagonist, is an anesthetic agent that has been used by some pain specialists for CRPS. There is a growing body of clinical evidence to support the use of ketamine in the treatment of neuropathic pain, especially CRPS. This meta-analysis study was aimed to examine the efficacy of ketamine in the treatment of CRPS. RECENT FINDINGS: A search of Embase, Pubmed, Web of Knowledge, Cochrane, Clinical Trial.gov , and FDA.gov between Jan 1, 1950, and August 1, 2017, was conducted to evaluate ketamine infusion therapy in the treatment of CRPS. We selected randomized clinical trials or cohort studies for meta-analyses. I 2 index estimates were calculated to test for variability and heterogeneity across the included studies. The primary outcome is pain relief. The effect of ketamine treatment for complex regional pain syndrome was assessed by 0-10 scale numerical rating pain score. The secondary outcome is the pain relief event rate, which is defined as the percentage of participants who achieved 30% or higher pain relief in each of the qualified studies. Our meta-analysis results showed that the Ketamine treatment led to a decreased mean of pain score in comparison to the self-controlled baseline (p < 0.000001). However, there is a statistical significance of between-study heterogeneity. The immediate pain relief event rate was 69% (95% confidence interval (CI) 53%, 84%). The pain relief event rate at the 1-3 months follow-ups was 58% (95% CI 41%, 75%). The current available studies regarding ketamine infusion for CRPS were reviewed, and meta-analyses were conducted to evaluate the efficacy of ketamine infusion in the treatment of CRPS. Our findings suggested that ketamine infusion can provide clinically effective pain relief in short term for less than 3 months. However, because of the high heterogeneity of the included studies and publication bias, additional random controlled trials and standardized multicenter studies are needed to confirm this conclusion. Furthermore, studies are needed to prove long-term efficacy of ketamine infusion in the treatment of CRPS.

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

OBJECTIVES: Complex regional pain syndrome is a challenging condition that includes a broad spectrum of sensory, autonomic, and motor features predominantly in extremities recovering from a trauma. Few large-scale studies have addressed occurrence of and factors associated with complex regional pain syndrome (CRPS) following orthopedic treatment. The present study aimed to identify factors associated with post-treatment development of CRPS. METHODS: Using the Danish Patient Compensation Association's database, we identified 647 patients claiming post-treatment CRPS between 1992 and 2015. Age, gender, initial diagnosis, treatment, and amount of compensation were extracted. Multivariate logistic regressions were performed to identify variables associated with approval of the claim. For carpal tunnel syndrome (CTS) patients, we registered whether symptoms were bilateral or unilateral and if neurophysiology prior to treatment was pathologic. RESULTS: The following ratios were found: women:men was 4:1, primary diagnosis to the upper limb:lower limb was 2.5:1, and surgical:nonsurgical treatment was 3:1. Mean age was 47.5 ± 13.7 years, and no intergender difference was detected. Antebrachial fracture (23%) and CTS (9%) were the most common primary conditions. Surgical treatment was associated with approval of the claim (odds ratio 3.5, 95% confidence interval 2.3 to 5.3; P < 0.001). Half of CTS patients had normal neurophysiology prior to surgery; among patients with unilateral symptoms, 71.4% had normal neurophysiology. CONCLUSIONS: Female gender, surgical treatment, and treatment to the upper limb were risk factors. Elective surgery accounted for a large number of post-treatment CRPS patients. In CTS patients developing CRPS, normal neurophysiological examination findings were common, and it could be suspected that these patients were suffering from an pre-clinical stage of CRPS, not CTS.

Spinal Cord Stimulator Explantation: Motives for Removal of Surgically Placed Paddle Systems.

BACKGROUND: Despite requiring successful trials prior to implantation, spinal cord stimulation (SCS) systems for pain are often later removed. Removing surgically implanted hardware subjects patients to the risks and discomfort of a second surgery, threatens the cost-effectiveness of SCS, and limits the perceived durability of SCS technology for pain problems. OBJECTIVE: To investigate patterns of reasons given among patients who underwent SCS explant surgery (SCSES). METHODS: Retrospective review of SCSES cases over 17 years at Allegheny General Hospital, Pittsburgh, PA. RESULTS: 165 patients underwent SCSES between 1997 and 2014. The top 3 reasons for explantation were inadequate pain control (IPC; 73%), hardware discomfort (22%), and need for magnetic resonance imaging (MRI) (10%). Other less frequent reasons were infection (9%), painful dysesthesias (9%), electrical arcing (4%), resolution of inciting symptoms (4%), weakness (2%), pseudomeningocele (1%) and muscle spasms (1%). CONCLUSION: Inadequate pain control is the most common reason for SCSES. Advances in technology are needed to improve the quality and duration of pain control, as well as to design improvements to make the hardware more comfortable. A significant number of implants are removed due to need for MRI, a fact obviating the need for MRI-compatible systems. Patients considering SCS paddle lead placement should be counseled on the most common reasons for later explantation.

Safety and Efficacy of Occipital Nerves Stimulation for the Treatment of Chronic Migraines: Randomized, Double-blind, Controlled Single-center Experience.

BACKGROUND: A recent multicenter study presented 52-week safety and efficacy results from an open-label extension of a randomized, sham-controlled trial for patients with chronic migraine (CM) undergoing peripheral nerve stimulation of the occipital nerves. We present the data from a single center of 20 patients enrolled at the Cleveland Clinic's Pain Management Department. METHODS: In this single center, 20 patients were implanted with a neurostimulation system, randomized to an active or control group for 12 weeks, and received open-label treatment for an additional 40 weeks. Outcomes collected included number of headache days, pain intensity, Migraine Disability Assessment (MIDAS), Zung Pain and Distress (PAD), direct patient reports of headache pain relief, quality of life, satisfaction, and adverse events (AEs). RESULTS: Headache days per month were reduced by 8.51 (±9.81) days (P < 0.0001). The proportion of patients who achieved a 30% and 50% reduction in headache days and/or pain intensity was 60% and 35%, respectively. MIDAS and Zung PAD were reduced for all patients. Fifteen (75%) of the 20 patients at the site reported at least one AE. A total of 20 AEs were reported from the site. CONCLUSION: Our results support the 12-month efficacy of 20 CM patients receiving peripheral nerve stimulation of the occipital nerves in this single-center trial.

A Comprehensive Outcome-Specific Review of the Use of Spinal Cord Stimulation for Complex Regional Pain Syndrome.

BACKGROUND: Complex regional pain syndrome (CRPS) is a painful, debilitating affliction that is often difficult to treat. It has become common international practice to use spinal cord stimulation (SCS) for the treatment of CRPS as other therapies fail to provide adequate relief, quality of life, or improvement in function. This comprehensive outcome-specific systematic review of the use of SCS for CRPS was performed to elucidate the available evidence with focus on clinically relevant patient-specific outcomes. METHODS: A systematic review of the literature was conducted to evaluate the effects of SCS on patients with CRPS for the following outcomes and provide summary levels of evidence in regard to each outcome: perceived pain relief, pain score, resolution of CRPS signs, functional status, quality of life, psychological impact, sleep hygiene, analgesic medication utilization, and patient satisfaction with SCS therapy. Search terms included "complex regional pain syndrome," "spinal cord stimulation," and "reflex sympathetic dystrophy," without restriction of language, date, or type of publication, albeit only original data were included in analyses. Of 30 studies selected, seven systematic reviews were excluded, as were four studies reporting combination therapy that included SCS and other therapies (ie, concurrent peripheral nerve stimulation, intrathecal therapy) without clear delineation to the effect of SCS alone on outcomes. A total of 19 manuscripts were evaluated. RESULTS: Perceived pain relief, pain score improvement, quality of life, and satisfaction with SCS were all rated 1B+, reflecting positive high-level (randomized controlled trial) evidence favoring SCS use for the treatment of CRPS. Evidence for functional status improvements and psychological effects of SCS was inconclusive, albeit emanating from a randomized controlled trial (evidence level 2B±), and outcomes evidence for both sleep hygiene and resolution of CRPS signs was either nonexistent or of too low quality from which to draw conclusions (evidence level 0). An analgesic sparing effect was observed in nonrandomized reports, reflecting an evidence level of 2C+. CONCLUSIONS: Spinal cord stimulation remains a favorable and effective modality for treating CRPS with high-level evidence (1B+) supporting its role in improving CRPS patients' perceived pain relief, pain score, and quality of life. A paucity of evidence for functional improvements, resolution of CRPS signs, sleep hygiene, psychological impact, and analgesic sparing effects mandate further investigation before conclusions can be drawn for these specific outcomes.

Silas Weir Mitchell and "The Strange Case of George Dedlow".

It has been said of Silas Weir Mitchell (1829-1914) that as a young man he was first among the physiologists of his day, in middle age first among physicians, and as an older man, one of the most noted novelists of his country. Mitchell's novels were written in his later life as a means to avoid boredom during lengthy summer vacations that were the norm for that time among the affluent members of Philadelphia society. These novels were criticized by some because of poor plots, which in some instances failed to move along, or for text that offered a stereotyped depiction of genteel society and the effects that war or personal disaster had on the characters' behavior The criticism came despite the fact that all critics agreed that Mitchell's portrayals of psychopathology in his fictional characters was unique and accurate. However, in his 30s, Mitchell had written and by chance had published a fictional short story that not only transcended such criticisms but became immensely popular. "The Strange Case of George Dedlow" portrays a union officer who was not a physician but who had some medical background and who sustained a series of war wounds leading to severe nerve pain, the author's first description of causalgia, multiple amputations, and the psychological as well as physical symptoms of phantom limb syndrome. The protagonist tells of his torments in the first person in a very engaging fashion. Thus, long before he began writing his, at that time, acclaimed novels in the 1880s, Mitchell wrote a piece of fiction that combines accurate and very important medical observations with fiction of great historical interest. The following rendering of this now classic short story includes selected quotes and some interpretation and is perhaps appropriate for this year, 2 years after the centenary year of his death in 1914.

[Complex regional pain syndrome in nerve root compression and after spinal surgery]. / Komplexes regionales Schmerzsyndrom bei Nervenwurzelkompression und nach Wirbelsäulenoperation.

Complex regional pain syndrome (CRPS) is an extremely painful and partially disabling disease. It often occurs secondary to trauma, but also spontaneously. The emergence of CRPS has been reported following nerve root compression and/or spinal surgery, but its incidence is unknown. In this article, the present knowledge about the incidence of CRPS in the context of nerve root compression and spine surgery is reviewed and therapeutic and diagnostic consequences are discussed.

Incidence of complex regional pain syndrome after foot and ankle surgery.

Complex regional pain syndrome (CRPS) is an uncommon complication of orthopedic surgery, and few investigators have considered the incidence in foot and ankle surgery. In the present retrospective cohort study of 390 patients who had undergone elective foot and/or ankle surgery in our department from January to December 2009, the incidence of postoperative CRPS was calculated and explanatory variables were analyzed. A total of 17 patients (4.36%) were identified as meeting the International Association for the Study of Pain criteria for the diagnosis of CRPS. Of the 17 patients with CRPS, the mean age was 47.2 ± 9.7 years, and 14 (82.35%) were female. All the operations were elective, and 9 (52.94%) involved the forefoot, 3 (17.65%) the hindfoot, 3 (17.65%) the ankle, and 2 (11.76%) the midfoot. Twelve patients (70.59%) had new-onset CRPS after a primary procedure, and 5 (29.41%) had developed CRPS after multiple surgeries. Three patients (17.65%) had documented nerve damage intraoperatively and thus developed new-onset CRPS type 2. Blood test results were available for 14 patients (82.35%) at a minimum of 3 months postoperatively, and none had elevated inflammatory markers. Five of the patients (29.41%) were smokers, and 8 (47.06%) had had a pre-existing diagnosis of anxiety and/or depression. From our findings, we recommend that middle-age females and those with a history of anxiety or depression, who will undergo elective foot surgery, should be counseled regarding the risk of developing CRPS during the consent process. We recommend similar studies be undertaken in other orthopedic units, and we currently are collecting data from other orthopedic departments within Scotland.

Complex Regional Pain Syndrome in Cancer Cases: Current Knowledge and Perspectives.

Background: Complex regional pain syndrome (CRPS) is a disabling painful disorder caused by many different and poorly understood mechanisms. It often affects the distal limbs and usually happens as consequence of a trauma. Its severity can remarkably affect patients' quality of life. When this painful complication happens in a cancer patient, the impact may be exponential. To date, there is limited knowledge of the surrounding circumstances of CRPS cases in this population. Methods: We present two clinical cases of patients diagnosed with cancer-related pain presenting with symptoms and signs compatible with CRPS. In one case, CRPS was attributed to direct tumor nerve compression, and it responded successfully to an interventional pain procedure. The second case was associated with a Zoster infection in an immunocompromised cancer patient. Patient responded to multidisciplinary pain management strategies. Additionally, we conducted a literature review to investigate the coexistence of cancer pain and CRPS and suggest some pathophysiology mechanisms of action. Results and Discussion: Literature reviewed and potential pathophysiology mechanisms are simultaneously explored in terms of classification, etiopathology, evidence, challenges, and future scientific directions. Conclusion: Comorbid CRPS can impact negatively in cases of cancer pain by affecting their diagnosis and treatment. Further studies are necessary to elucidate how these two conditions present together and how they can be better addressed.

Clinical course of a complex regional pain syndrome type II in upper limb.

INTRODUCTION: the complex regional pain syndrome type II, also called causalgia, is a rare clinical condition that appears after a traumatic or surgical event with evidence of nervous system involvement. Its clinical presentation is the consequence of a multifactorial pathogenic process that involves peripheral and central mechanisms and has variable clinical manifestations. We present the photographic record of a patient with complex regional syndrome type II. CLINICAL CASE: 43-year-old patient who consulted for neuropathic pain during the last four years, of severe intensity, associated with sensory, vasomotor and trophic changes in the right upper limb, as a consequence of neurectomy of the palmar digital nerves of the third finger. CONCLUSION: achieving the photographic record of the clinical phases of complex regional pain syndrome type II in its entirety is difficult, because not all patients present all clinical phases, a fact that gives relevance to this case.

INTRODUCCIÓN: el síndrome doloroso regional complejo (SDRC) tipo II, también llamado causalgia, es una condición clínica poco frecuente que aparece después de un evento traumático o quirúrgico con evidencia de afectación del sistema nervioso. Su presentación clínica es consecuencia de un proceso patogénico multifactorial que involucra mecanismos periféricos y centrales y tiene manifestaciones clínicas variables. Presentamos el registro fotográfico de un paciente con síndrome regional complejo tipo II. CASO CLÍNICO: paciente de 43 años que consultó por dolor neuropático durante los últimos cuatro años, de intensidad severa, asociado a cambios sensoriales, vasomotores y tróficos en miembro superior derecho, como consecuencia de neurectomía de los nervios digitales palmares propios del tercer dedo. CONCLUSIÓN: lograr el registro fotográfico de las fases clínicas del SDRC tipo II en su totalidad resulta difícil, debido a que no todos los pacientes presentan todas las fases clínicas; hecho que otorga la relevancia a este caso.

Ketamine for Complex Regional Pain Syndrome: A Narrative Review Highlighting Dosing Practices and Treatment Response.

This is a narrative review of intravenous ketamine infusions for the treatment of complex regional pain syndrome (CRPS). It briefly covers the definition of CRPS, its epidemiology, and other treatments before introducing ketamine as the article's focus. A summary of ketamine's evidence base and its mechanisms of action is provided. The authors then review ketamine dosages reported in peer-reviewed literature for the treatment of CRPS, and their associated duration of pain relief. The observed response rates to ketamine and predictors of treatment response are also discussed.

Pulsed radiofrequency to stellate ganglion for brachial plexus injury-induced complex regional pain syndrome: A case series.

Brachial plexus injury (BPI) occurs commonly in young adults following trauma. This may result in the development of complex regional pain syndrome (CRPS) following injury, which is difficult to treat. We present a group of patients with CRPS secondary to BPI. These patients were managed with neuromodulation of the stellate ganglion (SG) with pulsed radiofrequency (PRF) and followed up for a period of 3 months to assess for pain relief and a decrease in the intake of medications after the intervention. PRF to SG was found to have significant pain relief lasting around three months.

Clinical practice guidelines for the management of patients with complex regional pain syndrome: a systematic appraisal using the AGREE II instrument.

Aim: Complex regional pain syndrome (CRPS) is a debilitating, painful condition of limbs that often arises after an injury and is associated with significant morbidity. Materials & methods: The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, used to assess the quality of clinical practice guidelines (CPGs), was used to evaluate seven CRPS management guideline. Results: Out of the seven CPGs evaluated using the AGREE II instrument, only one from Royal College of Physicians was found to have high-quality consensus guidelines for diagnosis and management of CRPS. Conclusion: Future CPGs should be backed by systematic literature searches, focus on guidelines clinical translation into clinical practice and applicability to the desired patient population.

Combining Stellate ganglion block and intravenous regional anesthesia to treat complex regional pain syndrome: A 19-years' experience in a tertiary center.

OBJECTIVES: To study reduction in pain score after treatment with intravenous regional anesthesia (IVRA) and Stellate ganglion block (SGB) combination on complex regional pain syndrome (CPRS) patients and to quantify patients' satisfaction with treatment and occurrence of complications. METHODS: This is a record-based retrospective review carried out in 2020, targeting patients treated in the University of Jordan Hospital, Amman, Jordan, over the years 2002-2020. RESULTS: Among 99 patients, a significant drop in pain scores occurred in 88% of the patients' sample. Gender, age, type of CRPS, and duration of symptoms didn't affect statistical results. An average of 8.6 sessions needed to achieve 50% drop in pain score, and 2-3 sessions for first clinical improvement. Patients with previous application of plaster of Paris had increased success rates. CONCLUSION: We find it practical, inexpensive, safe, and straightforward to combine SGB with IVRA for CRPS patients.