Evaluating the efficacy of botulinum toxin in treating complex regional pain syndrome: A systematic review.

Complex Regional Pain Syndrome (CRPS) is characterized by pain, swelling, limited range of motion, skin changes, vasomotor instability, and bone demineralization. This study aims to assess the efficacy of botulinum toxin type A (BoNT-A) in the treatment of CRPS. We conducted a systematic literature review following the PRISMA guidelines, using the PICO strategy (Patient, Intervention, Comparison and Outcome) with the following criteria: P = Patients with CRPS; I = Botulinum toxin; C = Placebo or active drug; and O = Pain relief. Three randomized controlled trials with placebo controls were included, involving a total of 64 patients, 36 of whom received BoNT-A in doses ranging from 40U to 200U. The studies examined both lumbar sympathetic block and local application methods. Botulinum toxin shows promise in alleviating pain associated with CRPS, particularly when used as an adjunct to lumbar sympathetic blockade. However, the limited number of studies and small sample sizes impede reaching definitive conclusions regarding its efficacy and safety. Notably, local applications (intradermal or subcutaneous) require further investigation, as current evidence is insufficient and reports indicate patient discomfort. While preliminary findings suggest potential benefits of BoNT-A in managing CRPS, larger randomized trials are necessary to confirm its efficacy and safety.

Animal models of complex regional pain syndrome: A scoping review.

BACKGROUND: complex regional pain syndrome (CRPS) leads to a debilitating chronic pain condition. The lack of cause, etiology, and treatment for CRPS has been widely explored in animal models. OBJECTIVE: Provide a comprehensive framework of the animal models used for investigating CRPS. ELIGIBILITY CRITERIA: Preclinical studies to induce the characteristics of CRPS, with a control group, in any language or publication date. SOURCES OF EVIDENCE: The search was performed in the Medline (PubMed) and ScienceDirect databases. RESULTS: 93 studies are included. The main objective of the included studies was to understand the CRPS model. Rats, males and adults, exposed to ischemia/reperfusion of the paw or fracture of the tibia were the most common characteristics. Nociceptive evaluation using von Frey monofilaments was the most widely adopted in the studies. CONCLUSIONS: For the best translational science between the animal models and individuals with CRPS, future studies should include more heterogeneous animals, and multiple assessment tools, in addition to improving the description and performance of measures that reduce the risk of bias.

Rol de la densitometría ósea como herramienta diagnóstica y de control en el síndrome de dolor regional complejo: reporte de un caso / Role of bone densitometry as a diagnostic and monitoring tool in complex regional pain syndrome: report of a case

El síndrome de dolor regional complejo (SDRC) es una patología poco frecuente, caracterizada por dolor crónico y cambios locales del sitio afectado. Ocurre en forma posterior a un traumatismo, o, menos frecuentemente, sin desencadenante claro. El diagnóstico se realiza de forma clínica, evaluando la presencia de hallazgos típicos detallados en los criterios de Budapest, como el dolor continuo y desproporcionado, y síntomas y signos típicos, como edema, asimetría térmica y disminución del rango de movilidad. Los estudios por imágenes, así como la radiografía, la resonancia magnética o el centellograma óseo de 3 fases, también brindan información valiosa, sobre todo en los casos que se presentan con más dudas, y para realizar diagnóstico diferencial de otras patologías. En este sentido, la medición de la densidad mineral ósea por absorciometría dual de rayos X (DXA) se presenta también como herramienta de utilidad, no solo en la fase diagnóstica, al evidenciar la mayor desmineralización del miembro afectado, sino también en la evaluación de la respuesta terapéutica a bifosfonatos. Presentamos el caso de una paciente con SDRC del miembro inferior, donde la densitometría ósea resultó de gran utilidad en su manejo clínico. (AU)

Complex regional pain syndrome (CRPS) is a rare pathology, characterized by chronic pain and local changes of the affected site. It occurs after trauma or, less frequently, without a clear trigger. The diagnosis is made clinically, evaluating the presence of typical findings detailed in the Budapest criteria, such as continuous and disproportionate pain, and typical signs and symptoms, like edema, thermal asymmetry, and decreased range of motion. Imaging studies, such as radiography, magnetic resonance imaging, or 3-phase bone scintigraphy also provide valuable information, especially in cases that present with more doubts, and to make a differential diagnosis with other pathologies. In this regard, the measurement of bone mineral density by dual X-ray absorptiometry (DXA) is also a useful tool, not only in the diagnostic phase, by showing the greater demineralization of the affected limb, but also in the evaluation of the therapeutic response to bisphosphonates. We present the case of a patient with CRPS of the lower limb, where bone densitometry was very useful in her clinical management. (AU)

Oleaginous extract from the fruits Pterodon pubescens Benth induces antinociception in animal models of acute and chronic pain.

ETHNOPHARMACOLOGICAL RELEVANCE: Pterodon pubescens Benth is a medicinal plant commonly used for therapeutic purposes in folk medicine for rheumatic diseases' treatment. In the present work we analyzed the chemical composition of the oleaginous extract of P. pubescens Benth (OEPp) and extended the antinociceptive effect of OEPp evaluating its role on animal models of acute and chronic pain. MATERIALS AND METHODS: The antinociceptive and antiedematogenic effects of OEPp (3-100mg/kg, i.g.) were evaluated in the formalin test; mechanical allodynia in the postoperative pain and complex regional pain syndrome type-I (CRPS-I) animal models; and thermal hyperalgesia was induced by plantar incision. Finally, we performed a phytochemical analysis of OEPp. RESULTS: The chemical composition of OEPp was analyzed by mass spectrometry (GC/MS) and eight sesquiterpene compounds were identified, i.e. three major sesquiterpene (E-cariofilene, γ-muurolene, biciclogermacrene), and nine vouacapane diterpenes, four of which showed in major concentration (6α-acetoxyvouacapane, 6α,7ß-dimetoxivouacapan-17-ene, 6α-acetoxy,7ß-hidroxyvouacapane, 6α,7ß-diacetoxycouacapane). Furthermore, the results of the present study demonstrate, for the first time, that the OEPp reduced mechanical allodynia in the postoperative pain and CRPS-I animal models. OEPp also increased the paw withdrawal latency in hot- and cold-plate tests in the postoperative pain model. In addition, the present work confirms and extends previous data from literature showing that systemic administration of OEPp caused significant inhibition against both phases of pain response to formalin intraplantar injection and edema formation. CONCLUSIONS: Together, present and previous findings show that OEPp given intra-gastrically caused significant inhibition against both phases of formalin intraplantar injection and effectively inhibited mechanical and thermal hyperalgesia in the postoperative pain and CRPS-I animal models.

Buprenorfina transdérmica en el manejo del dolor crónico nociceptivo y neuropático no oncológico en ortopedia / Buprenorfine transdermal matrix patch in the treatment of chronic nociceptive non malignant pain and neurophatic pain in the orthopaedic patology

Objetivo: siendo el año del dolor musculoesquelético, es importante evitar el subtratamiento, dado la prevalencia de dolor crónico, los costos, limitación funcional y disminución de la calidad de vida en el paciente ortopédico, requiriéndose de vías menos invasivas, como la administración transdérmica, a través de sistema matricial de buprenorfina, en base a su liposolubilidad, y biodisponibilidad, sin riesgo de hiperalgesia ni afectación del sistema inmune, considerando su efecto techo en depresión respiratoria, y su empleo en comorbilidad renal y hepática. Material y métodos: estudio longitudinal, prospectivo, aleatorizado, de septiembre de 2008 a febrero de 2010, en el servicio de algología de orthocaz, unidad de ortopedia. N=108 de ambos sexos bajo consentimiento informado. Resultados: prevalencia de dolor en consulta externa de ortopedia r= 60-80 por ciento, x = 70, el crónico nociceptivo mayor de 30 por ciento y neuropático 1, 5 por ciento con predominio en el sexo femenino de 53,8 por ciento y, etiológicamente, el síndrome de columna fallida ocupa 40,7 por ciento, osteoartrosis 44, 4 por ciento, edad X= 66,59 años r= 20-85, dolor neuropático crónico secundario a metástasis en columna lumbar 3,7. La causa más común fue cáncer prostático, síndrome complejo regional 3,7 por ciento, el tamaño del efecto (EZ) fue de 1,2 el NNT= 4, a la 3ra semana se incrementó el dolor incidental e irruptivo, a partir del 10º día disminuyeron los efectos secundarios, como la somnolencia y nausea. Discusión y conclusiones: la osteoartritis, el síndrome de columna fallida, conducto lumbar estrecho mixto, síndrome complejo regional, secuelas de fracturas, prótesis fallidas, secuelas de displasia del desarrollo de la cadera, síndrome doloroso lumbar crónico, son padecimientos musculoesqueléticos en el que se aceptan el manejo de opiodes clase 3 de la OMS, de libración prolongada, como la buprenorfina...

Objetive: being the international year of the pain skeletal muscle, it is important to avoid the sub treatment, dice the prevalence of chronic pain, with the costs, functional limitation and diminution of the quality of life in the orthopedic patient requiring itself of less invasive routes as it is it the transdermal administration through matrix system of buprenorfina, on the basis of his high lip solubility without risk of hiperalgesia nor affectation of inmune system, considering his effect ceiling in respiratory depression, and its use in renal and hepatic comorbidity. Material and methodology: longitudinal, prospective study, randomized, of September of the 2008 to February 2010, in the service of algology of Orthocaz unit of N= orthopedics 108 both sexes, under informed consent. Results: Prevalence of pain in external consultation of orthopedics r= 60-80 per cent, x =70, the chronic greater nociceptive of 30 percent and neurophatic 1,5 percent with predominance in 53,8 percent feminine sex etiology the syndrome of insolvent column occupies 40,7 percent, osteoartrosis 44,4 percent, X= age 66,59 years, r= 20-85, secondary chronic neuropathic pain to metastasis in 3,7 lumbar column the cause most common prostate cancer, regional complex syndrome 3,7 percent the size of effect (EZ) the EU of 1,2 NNT= 4, to third week increase the incidental and irruptive pain, from the 10 day diminished the indirect effect, as drowsiness and feels nauseous. Discussion and and conclusions osteoarthritis, syndrome of insolvent column, lumbar conduit narrow compound, regional complex syndrome, sequels of fractures, prosthesis insolvent, sequels of dysplasia of the developement of the hip, chronic lumbar painful syndrome, are sufferings skeletal muscle in wich the handing of opiods is accepted class III, of the WHO of liberation prolonged as it is it buprenorfina transdermal, wih progressive degree, and to allow tolerability.

Local anesthetic sympathetic blockade for complex regional pain syndrome.

BACKGROUND: Local anesthetic blockade of the sympathetic chain is widely used to treat reflex sympathetic dystrophy (RSD) and causalgia. These two pain syndromes are now conceptualized as variants of a single entity: complex regional pain syndrome (CRPS). A recent meta-analysis of the topic has been published. However, this study only evaluated studies in English language and therefore it could have overlooked some randomized controlled trials. OBJECTIVES: This systematic review had three objectives: to determine the likelihood of pain alleviation after sympathetic blockade with local anesthetics in the patient with CRPS; to assess how long any benefit persists; and to evaluate the incidence of adverse effects of the procedure. SEARCH STRATEGY: We searched the Cochrane Pain, Palliative and Supportive Care Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS, and conference abstracts of the World Congresses of the International Association for the Study of Pain. Bibliographies from retrieved articles were also searched for additional studies. SELECTION CRITERIA: We considered for inclusion randomized controlled trials that evaluated the effect of sympathetic blockade with local anesthetics in children or in adult patients to treat RSD, causalgia, or CRPS. DATA COLLECTION AND ANALYSIS: The outcomes of interest were the number of patients who obtained at least 50% of pain relief shortly after sympathetic blockade (30 minutes to 2 hours) and 48 hours or later. We also assessed the presence of adverse effects in each treatment arm. A random effects model was used to combine the studies. MAIN RESULTS: Two small randomized double blind cross over studies that evaluated 23 subjects were found. The combined effect of the two trials produced a relative risk (RR) to achieve at least 50% of pain relief 30 minutes to 2 hours after the sympathetic blockade of 1.17 (95% CI 0.80-1.72). It was not possible to determine the effect of sympathetic blockade on long-term pain relief because the authors of the two studies evaluated different outcomes. AUTHORS' CONCLUSIONS: This systematic review revealed the scarcity of published evidence to support the use of local anesthetic sympathetic blockade as the 'gold standard' treatment for CRPS. The two randomized studies that met inclusion criteria had very small sample sizes, therefore, no conclusion concerning the effectiveness of this procedure could be drawn. There is a need to conduct randomized controlled trials to address the value of sympathetic blockade with local anesthetic for the treatment of CRPS.

Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: a narrative and systematic review.

OBJECTIVE: There is growing controversy on the value of blocking the sympathetic nervous system for the treatment of complex regional pain syndromes (CRPS). The authors sought to evaluate the efficacy of sympathetic blockade with local anesthetic in these syndromes. In addition, they performed a comprehensive review of the pathophysiology and other treatments for CRPS. DESIGN: Systematic review of the literature was performed. MEDLINE was searched from 1966 through 1999. The authors identified only three randomized controlled trials (RCTs) that evaluated sympathetic blockade with local anesthetic, but because of differences in study design they were unable to pool the study data. The authors therefore included nonrandomized studies and case series. INTERVENTIONS: Studies were included if local anesthetic sympathetic blockade was used in at least 10 patients. Studies were excluded if continuous infusion techniques, somatic nerve blocks, or combined sympatholytic therapies were evaluated. OUTCOME MEASURES: Pain relief was classified as full, partial, or absent. The lack of a comparison group in the studies allowed only the calculation of distribution of the response categories, and the sum of the pooled rates does not equal 100%. RESULTS: Twenty-nine studies were included that evaluated 1,144 patients. Nineteen studies were retrospective, 5 prospective case series, 3 RCTs, and 2 nonrandomized controlled studies. The quality of the publications was generally poor. Twenty-nine percent of patients had full response, 41% had partial response, and 32% had absent response. It was not possible to estimate the duration of pain relief. CONCLUSIONS: This review raises questions as to the efficacy of local anesthetic sympathetic blockade as treatment of CRPS. Its efficacy is based mainly on case series. Less than one third of patients obtained full pain relief. The absence of control groups in case series leads to an overestimation of the treatment response that can explain the findings.