Interventions For Treatment Of Pain Research Articles

Role of Neuregulin-1/ErbB Signaling in Stem Cell Therapy for Spinal Cord Injury-Induced Chronic Neuropathic Pain

Chronic neuropathic pain is a common and debilitating consequence of spinal cord injury (SCI). In a rat contusion injury model, we observed that chronic neuropathic pain is present on day 7 after SCI and persists for the entire 56-day observation period. However, currently available pain therapies are inadequate for SCI-induced neuropathic pain. In this study, we show that spinal transplantation of mouse embryonic stem cell-derived oligodendrocyte progenitor cells (OPCs) enhances remyelination in the injured spinal cord and reduces SCI-induced chronic neuropathic pain. Moreover, we found that SCI reduces the protein level of neuregulin-1 and ErbB4 in the injured spinal cord and that OPC transplantation enhances the spinal expression of both proteins after SCI. Finally, intrathecal injection of neuregulin-1 small interfering RNA, but not the control nontarget RNA, diminishes OPC transplantation-produced remyelination and reverses the antinociceptive effect of OPC transplantation. Our findings suggest that the transplantation of embryonic stem cell-derived OPCs is an appropriate therapeutic intervention for treatment of SCI-induced chronic neuropathic pain, and that neuregulin-1/ErbB signaling plays an important role in central remyelination under pathological conditions and contributes to the alleviation of such pain.

Case study: Use of vibration therapy in the treatment of diabetic peripheral small fiber neuropathy

The aim of the study was to describe a case of type II diabetic peripheral small fiber neuropathic pain treated with whole body vibration therapy after a failed trial of conventional drugs and interventional pain management. A 64-year-old male had chronic diabetic peripheral neuropathic pain in his both feet for about 2 years. The patient tried multiple pain medications and various interventional pain treatments without significant pain relief. After 4 weeks of vibration treatment, which targeted the feet the patient's pain level and gait patterns significantly improved. These findings illustrate the importance of considering whole body vibration as a complimentary treatment in patients with diabetic peripheral neuropathic pain.

A Characterization of Pain in Racially and Ethnically Diverse Older Adults

This article presents a critical review of the influence of interracial and ethnic variation on pain prevalence, intensity, interference/function/disability, and treatment in older adults. A search of scientific databases published from 1900 to 2011, using key words associated with pain, geriatrics, and race/ethnicity, identified 180 articles, of which 27 empirical studies met the inclusion criteria. Of the retained articles, 17 reported that race/ethnicity was a statistically significant factor at p < .05. Minority older adults reported a higher prevalence of pain and higher pain intensity, and variable responses regarding function/disability compared with responses by non-Hispanic White older adults. Minority older adults were less likely to receive prescription pharmacologic treatments and surgery, and they were more likely to use complementary and alternative medicine treatments. There are interracial/ethnic differences in pain assessment and treatment interventions among older adults.

Mind-body interventions for treatment of phantom limb pain in persons with amputation.

Phantom limb pain (PLP) is a significant source of chronic pain in most persons with amputation at some time in their clinical course. Pharmacologic therapies for this condition are often only moderately effective and may produce unwanted adverse effects. There is growing empirical evidence of the therapeutic effectiveness of mind-body therapies for the relief of chronic pain; therefore, an exploration of their role in relieving amputation-related chronic pain is warranted. We undertook a focused literature review on mind-body interventions for patients with amputation who experience PLP. Because of study heterogeneity, only descriptive presentations of the studies are presented. Only studies of hypnosis, imagery, and biofeedback, including visual mirror feedback, were found; studies on meditation, yoga, and tai chi/qigong were missing from the literature. Few studies of specific mind-body therapies were dedicated to management of PLP, with the exception of mirror visual therapy. Overall, studies were largely exploratory and reflect considerable variability in the application of mind-body techniques, making definitive conclusions inadvisable. Nevertheless, the weight of existing findings indicates that a mind-body approach to PLP pain management is promising and that specific methods may offer either temporary or long-term relief, either alone or in combination with conventional therapies. The authors discuss the potential for usefulness of specific mind-body therapies and the relevance of their mechanisms of action to those of PLP, including targeting cortical reorganization, autonomic nervous system deregulation, stress management, coping ability, and quality-of-life. The authors recommend more and better quality research exploring the efficacy and mechanisms of action.

Ultrasound versus Fluoroscopy in Image-guided Pain Treatment

Ultrasound <i>versus</i> Fluoroscopy in Image-guided Pain Treatment

Towards Patient-Friendly Input Signal Design for Optimized Pain Treatment Interventions

We examine some of the challenges associated with generating input signals for identifying dynamics in pain treatment interventions while imposing “patient-friendly” constraints on the design. Standard clinical trials, while providing some useful information, are not the most suitable vehicle for understanding the dynamic response of dosage changes to participant response. Meanwhile, much of the work in classical input design, even that which incorporates “plant-friendly” considerations, may not result in clinically acceptable trials for human participants. In this paper, we describe some of the issues involved and suggest various approaches (leading ultimately to optimization-based formulations) to obtain input signals with desired spectral properties under time-domain constraints of importance to clinical practice. Numerical examples are shown to illustrate the proposed method with a hypothetical clinical trial of the drug gabapentin for the treatment of neuropathic pain.

Prevalence of Adverse Reactions to Radiopaque Contrast Reported by Patients Presenting for Interventional Pain Procedure

Adverse reactions to radiopaque contrast media (RCM) are well documented with a wide range of incidences reported. The objective of this study was to determine how many patients in a sample of 200 who presents for interventional pain treatments report a history of adverse reactions to RCM. Data from 200 outpatients were collected using a self-administered questionnaire. The questionnaire was designed to obtain information about prior exposure to RCM and any adverse events plus other general information about allergic reactions including known risk factors for allergic reactions. Demographic data and information about past medical history were obtained from each patient. Of the 200 patients surveyed, 16 reported having had an allergic reaction to RCM. The events met criteria for immediate hypersensitivity reaction. Chemotoxic reactions cannot be ruled out. Of factors associated with risk of allergic reaction, none were clearly more prevalent in subjects reporting an allergic reaction vs. subjects who did not. Atopic patients generally considered susceptible to contrast allergy reported no hypersensitivity reaction. The number of medications and foods the subjects reported caused them to have allergic reactions was extensive. Patients with a history suggestive of an immediate hypersensitivity reaction to RCM may report for interventional pain procedures normally performed with RCM. Patients who have experienced an immediate hypersensitivity reaction to RCM have increased risk for another reaction if injected again with contrast agent. Therefore, facilities should be prepared to implement measures to prevent recurrent reactions.

Heterogeneity of macrophages in injured trigeminal nerves: Cytokine/chemokine expressing vs. phagocytic macrophages

Macrophages are important immune effector cells in both innate and adaptive immune responses. Injury to peripheral nerves triggers activation of resident macrophages and infiltration of haematogenous macrophages, which they play critical roles in Wallerian degeneration and neuropathic pain. As macrophages are able to change their phenotypes in response to environment cues, we attempt to identify distinct phenotypes of macrophages in injured nerves and to understand the potential contribution of each macrophage subpopulation to the genesis of neuropathic pain associated with nerve injury. Rat mental nerves (terminal branches of trigeminal nerve) were loosely ligated. Sensitivity to mechanical stimuli at the lower lip area was monitored using calibrated von Frey Hairs. We examined the expression pattern of Iba-1, MAC1 and ED1 which allow us to reveal the immunophenotypes of macrophages at different time points post-injury. Functional status of each macrophage subpopulation was further investigated by colocalization with cytokines/chemokines, myelin basic protein and MHC II antigen, which reflect respectively secretory, phagocytic and antigen presentation properties of activated macrophages. Following nerve injury, a burst of Iba-1(+) macrophages was found in injured mental nerves. Among them, we detected two major immunophenotypes: MAC1(+) cytokines/chemokines secreting macrophages and ED1(+) phagocytic macrophages. Small, round shaped MAC1(+) macrophages were distributed essentially around the lesion site and existed only at early time points. Large, irregular and foamy ED1(+) macrophages were found among damaged nerve fibers and they persisted for at least 3 months post-injury. Although ED1(+) macrophages did not secrete inflammatory mediators, they were able to express neurotransmitter CGRP and MHC II at later time points. In parallel, we observed that mechanical allodynia developed after the nerve ligation was at its lowest level within 1 month. Although slightly increased afterwards, the head escape threshold maintained significantly lower than before injury until 3 months. We suggest that MAC1(+) macrophages contribute to the initiation of neuropathic pain by releasing cytokines/chemokines, and ED1(+) macrophages may contribute in maintaining the hypersensitivity under other mechanisms. Our results highlighted the heterogeneity and the plasticity of macrophages in response to the injury and provided further information on their potential involvement in neuropathic pain. Exploring the full spectrum of macrophage phenotypes in injured nerve is necessary. Individual macrophage population may be selectively targeted by cell-specific intervention for an effective treatment of neuropathic pain.

Clinical Trial Methodology of Pain Treatment Studies

The past century has seen immense progress in the advancement of methodology to evaluate efficacy of treatment interventions for acute and chronic pain. Continuing challenges revolve around how to best select and measure primary efficacy outcomes for a given analgesic trial. Recognizing the complex, multidimensional, sensory and emotional nature of pain and applying psychometric techniques have facilitated the development of several valid and reliable self-report measures that evaluate pain intensity, pain relief, and other important outcome domains relevant to pain treatment. In the setting of emerging new pain treatment strategies, careful consideration must be given to match current or novel outcome measures to the specific goals of a proposed trial. Future research is needed to directly compare current methods with newer measurement approaches for the critical goal of maximizing validity, reliability, and utility of different outcome measures in clinical trials of pain treatment.

The UK back pain subpopulation study: Predictors of outcome in patients receiving chiropractic treatment

Introduction: Non-specific low back pain is a common condition that continues to place a considerable burden on society. Various treatment approaches have emerged which are aimed at targeting non-specific low back pain and one of the most commonly recommended of these is spinal manipulative therapy, which is a central component of the chiropractic approach. However, despite observations in clinical practice in which some individuals respond well, results from clinical trials of treatment interventions for low back pain, such as chiropractic, are repeatedly seen to have small effect sizes. A plausible explanation for this is that low back pain may be considered a heterogeneous condition consisting of a number of subgroups of patients. Previously highlighted as a research priority, these subgroups and their predictive factors for outcome are beginning to be identified among low back pain patients receiving chiropractic treatment; however they are largely unstudied in the UK chiropractic patient population. The overall aim of this prospective cohort study was to attempt to identify predictors of outcomes in the short, medium and long term in low back pain patients undergoing chiropractic treatment in primary care settings throughout the UK. Methods: All practising members of the British Chiropractic Association were invited to participate in the study. Each chiropractor was required to recruit 10 consecutive low back pain patients. Patients were eligible for inclusion if they were between 18 and 60 years of age; presenting with a new episode of low back pain with or without leg pain; no treatment for low back pain within the previous 3 months; not pregnant; no contraindications to chiropractic care; a mobile phone user. All participating patients completed an informed consent form. Data were recorded utilising self report paper questionnaires by patients and chiropractors at baseline; and by patients only at the 4th visit, 3 months and 6 months follow-up. In addition, outcomes in the immediate short term were recorded from patients via text message on a daily basis for 7 days following the 1st visit. Baseline potential predictor variables encompassed demographics, clinical characteristic, clinical examination findings, work-related factors and psychosocial factors. The primary outcome was patient self-report global improvement. Patients were subgrouped according to the duration of the current episode of low back pain into acute (less than 2 weeks) and subacute/chronic (2 weeks or greater). Multivariate logistic regression analysis was used to construct prognostic models for baseline and change score variables at each follow-up. Results: Sixty-five chiropractors and 452 low back pain patients (222 acute; 230 subacute/chronic) participated in the study. The loss to follow-up at 6 months was approximately 65%. Almost 60% of patients participated in the text message study and the response rate was high (96%). The acute patients reported higher pain and disability at baseline; however a greater proportion of these patients were categorised as improved at each follow-up. The greatest drop in pain scores occurred in the 1st week in both subgroups. Several baseline predictor variables were independently associated with improvement at follow-up; however these differed between the subgroups with the exception of the patient-practitioner relationship. Early changes in pain were independently associated with improvement for the acute and subacute/chronic patients in the short and medium term. The discriminative ability of the baseline and change score prognostic models varied from weak to acceptable. Conclusion: The investigation presented here contributes to the body of research concerning prognostic factors, specifically those in the immediate short term, in the UK chiropractic LBP patient population and for being the largest study of its kind to date in the UK. Furthermore, this study highlights the potential impact of the patientpractitioner relationship on outcome in low back pain patients receiving chiropractic care. Although several baseline variables predicted improvement at follow-up, the importance of early change as a prognostic indicator is emphasised.

Injury and Liability Associated with Cervical Procedures for Chronic Pain

Prompted by an increase in interventional pain treatments performed at the level of the cervical spine, we investigated the characteristics and patterns of injury in malpractice claims collected from January 1, 2005 to December 31, 2008. We compared claims arising from cervical pain treatments with all other chronic pain claims collected from the American Society of Anesthesiologists' closed claims database between 2005 and 2008. Claims for spinal cord injury underwent in-depth analysis for mechanisms of injury and use of sedation during the procedure. Claims related to cervical interventions represented 22% (64/294) of chronic pain treatment claims. Patients who underwent cervical procedures were healthier (American Society of Anesthesiologists' score, 1-2; P < 0.001) and were more often women (P = 0.011). Of the patients who underwent a cervical procedure, 59% experienced spinal cord damage compared with 11% of patients with other chronic pain (P < 0.001), with direct needle trauma as the predominant cause (31%). General anesthesia or sedation was used in 67% of cervical procedure claims associated with spinal cord injuries but in only 19% of cervical procedure claims not associated with spinal cord injuries (P < 0.001). Of the patients who underwent cervical procedures and had spinal cord injuries, 25% were nonresponsive during the procedure compared with 5% of the patients who underwent cervical procedures and did not have spinal cord injuries (P < 0.05, κ = 0.52). Injuries related to cervical interventional pain treatment were often severe and related to direct needle trauma to the spinal cord. Traumatic spinal cord injury was more common in patients who received sedation or general anesthesia and in those who were unresponsive during the procedure. Further studies are crucial to define the usefulness of cervical interventions and to improve their safety.

Case study: Use of vibration therapy in the treatment of diabetic peripheral small fiber neuropathy

The aim of the study was to describe a case of type II diabetic peripheral small fiber neuropathic pain treated with whole body vibration therapy after a failed trial of conventional drugs and interventional pain management. A 64-year-old male had chronic diabetic peripheral neuropathic pain in both his feet for about 2years. The patient tried multiple pain medications and various interventional pain treatments without significant pain relief. After 4weeks of whole body vibration treatment the patient’s pain level and gait patterns significantly improved. These findings illustrate the importance of considering whole body vibration as a complimentary treatment in patients with diabetic peripheral neuropathic pain.

Anesthesia Literature Review

Anesthesia Literature Review

A systematic review on the effectiveness of complementary and alternative medicine for chronic non-specific low-back pain

The purpose of this systematic review was to assess the effects of spinal manipulative therapy (SMT), acupuncture and herbal medicine for chronic non-specific LBP. A comprehensive search was conducted by an experienced librarian from the Cochrane Back Review Group (CBRG) in multiple databases up to December 22, 2008. Randomised controlled trials (RCTs) of adults with chronic non-specific LBP, which evaluated at least one clinically relevant, patient-centred outcome measure were included. Two authors working independently from one another assessed the risk of bias using the criteria recommended by the CBRG and extracted the data. The data were pooled when clinically homogeneous and statistically possible or were otherwise qualitatively described. GRADE was used to determine the quality of the evidence. In total, 35 RCTs (8 SMT, 20 acupuncture, 7 herbal medicine), which examined 8,298 patients, fulfilled the inclusion criteria. Approximately half of these (2 SMT, 8 acupuncture, 7 herbal medicine) were thought to have a low risk of bias. In general, the pooled effects for the studied interventions demonstrated short-term relief or improvement only. The lack of studies with a low-risk of bias, especially in regard to SMT precludes any strong conclusions; however, the principal findings, which are based upon low- to very-low-quality evidence, suggest that SMT does not provide a more clinically beneficial effect compared with sham, passive modalities or any other intervention for treatment of chronic low-back pain. There is evidence, however, that acupuncture provides a short-term clinically relevant effect when compared with a waiting list control or when acupuncture is added to another intervention. Although there are some good results for individual herbal medicines in short-term individual trials, the lack of homogeneity across studies did not allow for a pooled estimate of the effect. In general, these results are in agreement with other recent systematic reviews on SMT, but in contrast with others. These results are also in agreement with recent reviews on acupuncture and herbal medicine. Randomized trials with a low risk of bias and adequate sample sizes are direly needed.Electronic supplementary materialThe online version of this article (doi:10.1007/s00586-010-1356-3) contains supplementary material, which is available to authorized users.

2. Cluster Headache

Cluster headache is a strictly unilateral headache that is associated with ipsilateral cranial autonomic symptoms and usually has a circadian and circannual pattern. Prevalence is estimated at 0.5 to 1.0/1,000. The diagnosis of cluster headache is made based on the patient's case history. There are two main clinical patterns of cluster headache: the episodic and the chronic. Episodic is the most common pattern of cluster headache. It occurs in periods lasting 7 days to 1 year and is separated by at least a 1-month pain-free interval. The attacks in the chronic form occur for more than 1 year without remission periods or with remission periods lasting less than 1 month. Conservative therapy consists of abortive and preventative remedies. Ergotamines and sumatriptan injections, sublingual ergotamine tartrate administration, and oxygen inhalation are effective abortive therapies. Verapamil is an effective and the safest prophylactic remedy. When pharmacological and oxygen therapies fail, interventional pain treatment may be considered. The effectiveness of radiofrequency treatment of the ganglion pterygopalatinum and of occipital nerve stimulation is only evaluated in observational studies, resulting in a 2 C+ recommendation. In conclusion, the primary treatment is medication. Radiofrequency treatment of the ganglion pterygopalatinum should be considered in patients who are resistant to conservative pain therapy. In patients with cluster headache refractory to all other treatments, occipital nerve stimulation may be considered, preferably within the context of a clinical study.

The Painless Brain: Lobotomy, Psychiatry, and the Treatment of Chronic Pain and Terminal Illness

This article examines the use of lobotomy as a treatment for chronic intractable pain and reconstructs then-common perceptions of pain and of the patients who suffered from it. It delineates the social expectations and judgments implicit in physicians' descriptions of the patients, analyzing what was expected from such patients and how the medical establishment responded to non-normative expressions of suffering. I argue that the medicalized response to an expectation for normativity demonstrates the convergence between psychiatric and palliative interventions. Based on a historically informed perspective of psychiatric interventions in the field of pain medicine, I examine the use of psychiatric medications for pain syndromes today and evaluate the interface between depression, chronic pain, and terminal illness. While not detracting from the medical imperative to alleviate pain, I question the usage of social criteria and normative judgments in the clinical decision of how to treat pain. What normalizing social function does the use of psychiatric interventions in pain treatment fulfill? This approach leads to a reexamination of perceptions of dualism in pain medicine.

Pain coping profiles in adolescents with chronic pain

This study sought to evaluate the extent to which the pain coping profiles observed by Walker and colleagues [28] in a sample of patients with chronic abdominal pain also were evident in a sample of adolescent patients who presented to a tertiary care clinic for evaluation of a variety of diverse pain conditions. In addition, we aimed to evaluate the relation of these pain coping profiles to patients’ emotional and physical functioning. Participants ( n = 254) were adolescent patients aged 12–17 years. Patients completed the Pain Response Inventory (PRI) as well as measures of pain, somatic symptoms, anxiety and depressive symptoms, and functional disability. Using the PRI classification algorithm developed by Walker and colleagues [28], we successfully classified all the patients in our sample. We also found that the pain coping profiles successfully differentiated among patients with different levels of symptoms, disability, and emotional distress, further demonstrating the external validity of these profiles. Results have implications for tailoring pain treatment interventions to patients’ particular coping profiles.

Interventional Pain Treatments for Cancer Pain

Cancer pain is prevalent and often multifactorial. For a segment of the cancer pain population, pain control remains inadequate despite full compliance with the WHO analgesic guidelines including use of co-analgesics. The failure to obtain acceptable pain or symptom relief prompted the inclusion of a fourth step to the WHO analgesic ladder, which includes advanced interventional approaches. Interventional pain-relieving therapies can be indispensable allies in the quest for pain reduction among cancer patients suffering from refractory pain. There are a variety of techniques used by interventional pain physicians, which may be grossly divided into modalities affecting the spinal canal (e.g., intrathecal or epidural space), called neuraxial techniques and those that target individual nerves or nerve bundles, termed neurolytic techniques. An array of intrathecal medications are infused into the cerebrospinal fluid in an attempt to relieve refractory cancer pain, reduce disabling adverse effects of systemic analgesics, and promote a higher quality of life. These intrathecal medications include opioids, local anesthetics, clonidine, and ziconotide. Intrathecal and epidural infusions can serve as useful methods of delivering analgesics quickly and safely. Spinal delivery of drugs for the treatment of chronic pain by means of an implantable drug delivery system (IDDS) began in the 1980s. Both intrathecal and epidural neurolysis can be effective in managing intractable cancer-related pain. There are several sites for neurolytic blockade of the sympathetic nervous system for the treatment of cancer pain. The more common sites include the celiac plexus, superior hypogastric plexus, and ganglion impar. Today, interventional pain-relieving approaches should be considered a critical component of a multifaceted therapeutic program of cancer pain relief.

A 50-Year-Old Man With Chronic Low Back Pain

Mr S, a 50-year-old man, has long-standing low back pain. His pain began more than 20 years earlier with a lumbar disk herniation and has persisted despite diskectomy. He has undergone numerous treatments, but he remains disabled with ongoing pain. His treatment course is used to frame the epidemiology and pathophysiology underlying acute and chronic lumbosacral and radicular pain. The roles of neuropathic pain medications, chronic opioid therapy, physical therapy, spinal manipulation, and multidisciplinary pain treatment programs are reviewed. The indications for and outcomes associated with interventional pain treatments, including epidural steroid injection, facet blocks and radiofrequency treatment for facet-related pain, intradiskal electrothermal therapy, spinal cord stimulation, and intrathecal drug delivery, are discussed. Clinicians are given an evidence-based approach to using available treatment options for low back pain.

Synthetic Lumbar Intervertebral Disk for Medical Education

Surgical treatment interventions for low-back pain are increasing. Surgical risk associated with new techniques can be reduced by practice on synthetic spine replicas. However, current models for surgical training on intervertebral disk procedures do not represent average patients because they exhibit variable degrees of degeneration. A low-cost synthetic intervertebral disk device with lifelike sensory and visual feedback to enhance surgeon training was developed. Design criteria for the synthetic analog intervertebral disks (IVDs) were based on observations of fresh frozen human cadaveric disks, surgeon input, and literature descriptions; prototypes were designed to mimic a Grade I-II lumbar IVD. Qualitative evaluation was done by interviewing orthopedic surgeons during mock surgeries on the model. The surgical feel was quantitatively evaluated by a mock nucleotomy on prototypes and cadaveric specimens using instrumented surgical tools. In qualitative analysis, two orthopedic surgeons commented that the visual and tactile qualities of the model were similar to disks of adult spine surgery patients. Quantitative test results showed similarities between human and analog disks. The inexpensive synthetic IVD design successfully replicated the main features of a human cadaveric disk.