Subarachnoid Block-Induced Deafferentation Pain Successfully Treated with Pentazocine.

Deafferentation pain induced by subarachnoid block (SAB) is rare, but it can appear in the form of recurrent phantom lower limb pain, new acute-onset stump pain in amputees, lower limb pain in patients with tabes dorsalis, and neuropathic pain. We have previously reported that thiopental is an effective treatment for deafferentation pain induced by therapeutic SAB applied to treat neuropathic pain of central origin. Here, we report the case of an amputee who developed new stump pain in his lower limb immediately after subarachnoid tetracaine was administered prior to appendectomy. A 51-year-old man who had previously undergone right below-knee amputation for acute arterial thrombosis, and who had not previously experienced chronic phantom limb or stump pain, was scheduled for emergency open appendectomy. For anesthesia, we induced SAB with a hyperbaric tetracaine solution. No paresthesia occurred during administration. However, the patient immediately complained of severe, lightning-bolt pain in the right lower limb stump after the SAB was established. He was given intravenous pentazocine, which promptly resolved the pain. Appendectomy was then performed under sedation using intravenous midazolam. The patient did not experience further deafferentation pain during his hospital stay and has reported no stump pain since discharge from the hospital. This case report suggests that SAB induces deafferentation pain in some patients and that this unusual pain can be treated with pentazocine.

Local anaesthetic sympathetic blockade for complex regional pain syndrome.

BACKGROUND: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews, 2005, Issue 4 (and last updated in the Cochrane Database of Systematic Reviews, 2013 issue 8), on local anaesthetic blockade (LASB) of the sympathetic chain to treat people with complex regional pain syndrome (CRPS). OBJECTIVES: To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure. SEARCH METHODS: For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 9), MEDLINE (Ovid), EMBASE (Ovid), LILACS (Birme), conference abstracts of the World Congresses of the International Association for the Study of Pain, and various clinical trial registers up to September 2015. We also searched bibliographies from retrieved articles for additional studies. SELECTION CRITERIA: We considered randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS compared to placebo, no treatment, or alternative treatments. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. The outcomes of interest were reduction in pain intensity, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table. MAIN RESULTS: We included an additional four studies (N = 154) in this update. For this update, we excluded studies that did not follow up patients for more than 48 hours. As a result, we excluded four studies from the previous review in this update. Overall we included 12 studies (N = 461), all of which we judged to be at high or unclear risk of bias. Overall, the quality of evidence was low to very low, downgraded due to limitations, inconsistency, imprecision, indirectness, or a combination of these.Two small studies compared LASB to placebo/sham (N = 32). They did not demonstrate significant short-term benefit for LASB for pain intensity (moderate quality evidence).One small study (N = 36) at high risk of bias compared thoracic sympathetic block with corticosteroid and local anaesthetic versus injection of the same agents into the subcutaneous space, reporting statistically significant and clinically important differences in pain intensity at one-year follow-up but not at short term follow-up (very low quality evidence).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB (very low quality evidence).Eight small randomised studies compared sympathetic blockade to various other active interventions. Most studies found no difference in pain outcomes between sympathetic block versus other active treatments (low to very low quality evidence).One small study compared ultrasound-guided LASB with non-guided LASB and found no clinically important difference in pain outcomes (very low quality evidence).Six studies reported adverse events, all with minor effects reported. AUTHORS' CONCLUSIONS: This update's results are similar to the previous versions of this systematic review, and the main conclusions are unchanged. There remains a scarcity of published evidence and a lack of high quality evidence to support or refute the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence, it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention, but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.

A Novel Compound Analgesic Cream (Ketamine, Pentoxifylline, Clonidine, DMSO) for Complex Regional Pain Syndrome Patients.

BACKGROUND: Evidence suggests that complex regional pain syndrome (CRPS) is a manifestation of microvascular dysfunction. Topical combinations of α2-adrenergic receptor agonists or nitric oxide donors with phosphodiesterase or phosphatidic acid inhibitors formulated to treat microvascular dysfunction have been shown to reduce allodynia in a rat model of CRPS-I. Driven by these findings, we assessed the outcomes of CRPS patients treated with a compound analgesic cream (CAC) consisting of ketamine 10%, pentoxifylline 6%, clonidine 0.2%, and dimethyl sulfoxide 6% to 10%. METHODS: An audit was conducted on 13 CRPS patients who trialed the CAC. A detailed report was compiled for each patient which comprised baseline characteristics, including CRPS description, previous treatments, and pain scores (numerical pain rating scale; 0 to 10). Recorded outcomes consisted of pain scores, descriptive outcomes, and concurrent medications/treatments, for which basic analysis was performed to determine the effectiveness of the CAC. Case reports are presented for 3 patients with varying outcomes. RESULTS: Nine patients (69%) reported pain/symptom reduction (4.4 ± 2.1 vs. 6.3 ± 1.9) with use of the CAC. Six patients reported sustained benefits after 2 months of CAC use, and 2 patients reported complete resolution of pain/symptoms: one had early CRPS-I and the other received a partial CRPS diagnosis. An otherwise medication refractory and intolerant patient found partial benefit with the CAC. CONCLUSIONS: These results demonstrate promise for this topical combination as a useful treatment in multimodal therapy for patients with CRPS, with the potential to resolve pain/symptoms in early CRPS patients.

A influência da suplementação de sulfato de condroitina na dor e nos aspectos funcionais associados à osteoartrose / Influence of chondroitin sulfate supplementation in pain and functional aspects associated with osteoarthritis

Introdução: A osteoartrose é a principal causa de limitação da funcionalidade e incapacidade nos idosos. Dentre os tratamentos farmacológicos está a suplementação com sulfato de condroitina. Objetivo: Realizar uma revisão sistemática sobre a influência do sulfato de condroitina na dor e aspectos funcionais associados à osteoartrose. Métodos: Foram utilizados os descritores "osteoarthritis" e "chondroitin". Os artigos foram selecionados de forma independente e cega, por dois pesquisadores. Foram incluídos somente ensaios clínicos primários, escritos na língua portuguesa, inglesa e espanhola entre 2005 a 2013. A escala PEDro foi utilizada como instrumento de avaliação. Resultados: Foram encontrados 1.916 estudos, permanecendo nove artigos para a análise. Dos nove analisados, quatro mostraram a eficácia da suplementação do sulfato de condroitina na redução da dor e da incapacidade funcional, enquanto cinco investigações não mostraram efeitos estatisticamente significantes. Conclusões: A influência do sulfato de condroitina na dor e aspectos funcionais na osteoartrose permanece questionável.

Introduction: Osteoarthritis is the leading cause of limitation of functionality and disability in the elderly. The supplementation with chondroitin sulfate is among the pharmacological treatments. Objective: To conduct a systematic review of the influence of chondroitin sulfate on pain and functional aspects associated with osteoarthritis. Methods: The keywords "osteoarthritis" and "chondroitin" were used. The articles were selected independently and blindly by two researchers. Only primary clinical trial, written in Portuguese, English and Spanish in the period between 2005 to 2013 were included. The PEDro scale was used as an evaluation tool. Results: A total of 1.916 studies with appropriate descriptors were found, and nine of these papers remained for analysis. Of these nine studies analyzed, four showed the effectiveness of supplementation of chondroitin sulfate in reducing pain and functional disability, while five studies showed no statistically significant effects. Conclusions: The influence of chondroitin sulfate in pain and functional aspects in osteoarthritis remains questionable.

Antiallodynic effect through spinal endothelin-B receptor antagonism in rat models of complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is a very complicated chronic pain disorder that has been classified into two types (I and II). Endothelin (ET) receptors are involved in pain conditions at the spinal level. We investigated the role of spinal ET receptors in CRPS. Chronic post-ischemia pain (CPIP) was induced in male Sprague-Dawley rats as a model for CRPS-I by placing a tourniquet (O-ring) at the ankle joint for 3h, and removing it to allow reperfusion. Ligation of L5 and L6 spinal nerves to induce neuropathic pain was performed as a model for CRPS-II. After O-ring application and spinal nerve ligation, the paw withdrawal threshold was significantly decreased at injured sites. Intrathecal administration of the selective ET-B receptor antagonist BQ 788 dose-dependently increased the withdrawal threshold in both CRPS-I and CRPS-II. In contrast, ET-A receptor antagonist BQ 123 did not affect the withdrawal threshold in either CRPS type. The ET-1 levels of plasma and spinal cord increased in both CRPS types. Intrathecal BQ 788 decreased the spinal ET-1 level. These results suggest that ET-1 is involved in the development of mechanical allodynia in CRPS. Furthermore, the ET-B receptor appears to be involved in spinal cord-related CRPS.

Local anaesthetic sympathetic blockade for complex regional pain syndrome.

BACKGROUND: This is an update of the original Cochrane review published in The Cochrane Library, 2005, Issue 4, on local anaesthetic blockade (LASB) of the sympathetic chain used to treat complex regional pain syndrome (CRPS). OBJECTIVES: To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure. SEARCH METHODS: We updated searches of the Cochrane Pain, Palliative and Supportive Care Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (Issue 11 of 12, 2012), MEDLINE (1966 to 22/11/12), EMBASE (1974 to 22/11/12), LILACS (1982 to 22/11/12), conference abstracts of the World Congresses of the International Association for the Study of Pain (1995 to 2010), and various clinical trial registers (inception to 2012). We also searched bibliographies from retrieved articles for additional studies. SELECTION CRITERIA: We considered for inclusion randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS. DATA COLLECTION AND ANALYSIS: The outcomes of interest were reduction in pain intensity levels, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. MAIN RESULTS: We included an additional 10 studies (combined n = 363) in this update. Overall we include 12 studies (combined n = 386). All included studies were assessed to be at high or unclear risk of bias.Three small studies compared LASB to placebo/sham. We were able to pool the results from two of these trials (intervention n = 23). Pooling did not demonstrate significant short-term benefit for LASB (in terms of the risk of a 50% reduction of pain scores).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB.Eight small randomised studies compared sympathetic blockade to another active intervention. Most studies found no difference in pain outcomes between sympathetic block and other active treatments.Only five studies reported adverse effects, all with minor effects reported. AUTHORS' CONCLUSIONS: This update has found similar results to the original systematic review. There remains a scarcity of published evidence to support the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.

Atypical odontalgia: an up-to-date view.

Atypical odontalgia (AO) is a little known chronic pain condition. It usually presents as pain in a site where a tooth was endodontically treated or extracted, in the absence of clinical or radiographic evidence of tooth pathology. It is a rare clinical challenge for most clinicians, which leads to the patients being referred to several specialists and sometimes undergoing unnecessary surgical procedures. The pain mechanisms involved in AO are far from clear, and numerous potential mechanisms have been suggested. Currently, the most accredited hypothesis is that AO is a neuropathic pain condition caused by deafferentation. The differential diagnosis of AO remains difficult, because it shares symptoms with many others pathologies affecting this area. Patients have difficulties accepting the AO diagnosis and treatment. As a result, they frequently change physicians, and may potentially also receive several invasive treatments, usually resulting in an aggravation of the pain. Although some patients do get complete pain relief following treatment, for most patients the goal should be to achieve adequate pain management. Currently, most management is based on expert opinion and case reports. More research and high quality randomized controlled trials are needed in order to develop evidence-based treatments, currently based on expert opinion or carried over from other neuropathic pain conditions in the orofacial region.

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

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

[Pronounced symptom deterioration in complex regional pain syndrome type II after isolated application of a highly concentrated capsaicin patch. A case report]. / Ausgeprägte Symptomverschlechterung bei CRPS Typ II nach einmaliger Applikation eines hochprozentigen Capsaicinpflasters. Ein Fallbericht.

Topical 8 % capsaicin is an established therapeutic option for the treatment of peripheral neuropathic pain. In accordance with the internationally accepted definition, complex regional pain syndrome (CRPS) type II is a form of neuropathic pain so that capsaicin plasters represent a treatment option. However, for the treatment of CRPS it is recommended that painful stimuli should be avoided but capsaicin induces a strong nociceptive stimulation and so its use is at present controversial. We report on the course of such an application in a patient who developed CRPS type II with intractable neuropathic pain after hallux surgery. As a result of a single treatment with capsaicin a pronounced recurrence developed with central nervous symptoms.

Ultrasound-guided continuous superficial peroneal nerve block below the knee for the treatment of nerve injury.

(CRPS) describes a constellation of symptoms including pain, trophic changes, hyperesthesia, allodynia, and dysregulation of local blood flow often following trauma. It is often confined to the extremities. Treatment of this disorder consists of a variety of modalities including systemic pharmacotherapy, local anesthetic injections or infusions, psychological nonpharmacotherapy, physical rehabilitation, and surgical intervention. Chronic pain not related to CRPS can also be treated with similar interventions. Despite the array of available therapies, it can still be difficult to manage. We report a case of a 19-year-old patient diagnosed by her surgeon as having CRPS Type II, secondary to foot trauma, which was treated with a continuous infusion of local anesthetic at the superficial peroneal nerve (SPN). While placement of peripheral nerve block catheters to augment chronic pain therapy is not novel, the application of a perineural catheter at the SPN has not been previously described.

[Complex regional pain syndrome--pathophysiology, clinical presentation and treatment]. / Kompleksni regionalni bolni sindrom--patofiziologija, klinicka slika i lijecenje.

In 1994, a consensus group of experts gathered by the International Association for the Study of Pain (IASP) agreed on new diagnostic criteria for the reflex sympathetic dystrophy (RSD) and causalgia, and renamed them complex regional pain syndrome (CRPS) types I and II, respectively. CRPS is a complex pathophysiological entity characterised by pain, trophic and vasomotoric changes, limited function of affected body part and relatively fast development of osteoporosis of affected region. We described possible pathophysiological mechanisms which caused the pain, clinical presentation of the disease and treatment which includes all available pharmacological modalities as well as interventional procedures.

Complex regional pain syndrome secondary to leprosy.

INTRODUCTION: Leprosy is a chronic infectious disease caused by Mycobacterium leprae affecting the skin and the nerves. Complex regional pain syndrome (CRPS/Sudeck's dystrophy) is a painful and disabling condition--a triad of autonomic, sensory, and motor symptoms disproportionate to the inciting event (inflammatory, infective, or traumatic nerve damage). CASE: A 20-year-old male presented with continuous pain, aggravated by cold and emotions, loss of fine touch and temperature sensation, redness, swelling, along lateral aspect of left hand and forearm with weakness in the grip of 6 months' duration. There was a 5-year history of sensory loss only over left index finger that he ignored. Examination revealed abnormal sensory and autonomic functions along left radial and median nerve distribution that were confirmed by nerve conduction studies suggestive of mononeuritis multiplex. Radial cutaneous nerve biopsy was suggestive of leprosy. Magnetic resonance imaging and ultrasonography showed no compressive etiology; however, MRI showed involvement of brachial plexus. Antileprosy, anti-inflammatory drugs, and steroids were given in view of neuritis because of lepra reaction with supportive measures of physiotherapy, transcutaneous electrical nerve stimulation, to no avail. A surgical median nerve decompression also failed to relieve the pain. Temporary stellate ganglion block improved the pain scale. Thus, excluding all other causes, the final diagnosis was CRPS secondary to leprosy. There is only one reported case of CRPS with leprosy. CONCLUSION: Leprous neuropathy caused the nerve damage that lead to CRPS type 2. Very rarely leprosy can lead to CRPS. CRPS is a diagnosis of exclusion.

Treatment of neuropathic deafferentation pain using DREZ lesions; long-term results.

INTRODUCTION: Deafferentation pain secondary to spinal cord injury, brachial plexus avulsion and other peripheral nerve injuries is often refractory to conventional treatments. This study evaluates the long-term efficacy of spinal DREZ (Dorsal Root Entry Zone) lesions for the treatment of neuropathic pain syndromes caused by deafferentation. PATIENTS AND METHODS: A series of 18 patients with refractory deafferentation pain treated with radiofrequency DREZ lesions is presented. The immediate and long-term efficacy was measured with the Visual Analogue Scale (VAS) before and after treatment, the patient's subjective evaluation, the percentage of patients returning to work and the reduction in pain medication. RESULTS: Pain on the VAS significantly decreased from 8.6 preoperatively to 2.9 (p<.001) at discharge. Over the long-term, with a mean follow-up of 28 months (6-108) pain remained at 4.7 on the VAS (p<0.002). The percentage of patients with moderate to excellent pain relief was 77% at discharge and 68% at the last follow-up. Pain medication was reduced in 67% of the patients and 28% returned to work. The best results were obtained in patients with brachial plexus avulsion, with a significant long-term pain relief in all cases. CONCLUSIONS: Radiofrequency DREZ lesion is an effective and safe treatment for refractory neuropathic pain caused by deafferentation.

Síndrome de dolor regional complejo tipo II: manejo interdisciplinario / Type II complex regional pain syndrome: multidisciplinary approach

El síndrome de dolor regional complejo tipo II o causalgia es un cuadro que se presenta con dolor intenso y síntomas autonómicos importantes, que alteran la calidad de vida de los pacientes. Sus mecanismos fisiopatológicos todavía están en discusión y la evidencia disponible para su manejo aún es escasa. Actualmente, la tendencia es hacia un manejo interdisciplinario que abarque terapias psicológicas, de rehabilitación, en conjunto con un correcto manejo del dolor.

Type II complex regional pain syndrome causes accute pain and autonomous symptoms that alter the patient's quality of life. Discussion with respect to the syndrome physiopathologic mechanisms is still open and available evidence is scarce. The present trend is the multidisciplinary approach with teams using psychological, rehabilitation and pain management therapies.

Sciatic neuropathy after lower-extremity trauma: successful treatment of an uncommon pain and disability syndrome in an adolescent.

Lower-extremity trauma is an uncommon but reported cause of sciatic nerve injury in children and adolescents. Failure to identify sciatic neuropathy after traumatic injury to the lower extremity may lead to the delayed institution of neuropathic pharmacotherapy, electrodiagnostic testing, physical therapy, and increased risk for the development of complex regional pain syndrome. This article presents a case of an adolescent male with neuropathic pain and weakness in the right lower extremity after traumatic injury. Spontaneous recovery of the injured nerve occurred with early institution of pharmacologic and physical therapies. Operative exploration and neurolysis were considered but were not ultimately necessary.

Management of complex regional pain syndrome type II using lidoderm 5% patches.

We report a case of a patient developing complex regional pain syndrome of the upper limb after a laceration injury with glass. The pain in his hand was resistant to all conventional modes of treatment. The pain reduced dramatically after a diagnostic lidocaine infusion and the reduction in pain lasted for 3 days. Following this the patient responded well to lidoderm 5% patches and achieved 80% pain relief with an improved range of movement in his hand.