Changes in pain perception after treatment for chronic pain

Pain threshold, sensitivity, response bias and ability to discriminate were measured before and after treatment for 15 improved and 15 unimproved chronic pain patients diagnosed as having myofascial pain dysfunction (MPD) syndrome. There were no differences between the groups before treatment. After treatment, the improved group showed an increase in pain threshold, sensitivity and ability to discriminate between different levels of painful stimulation and a decrease in response bias to report pain. The unimproved group showed no change.     

神经阻滞治疗慢性疼痛

神经阻滞是疼痛治疗的主体方法,本文重点介绍慢性疼痛新概念、神经阻滞治疗疼痛机制及其适应证.     

Ketamine for treatment of chronic pain: meta-analysis

The idea of using Ketamine to treat chronic pain is mainly based on the central antinoceptive effect of the substance acting as a noncompetitive antagonist at the NMDA-receptor. In the present meta analysis over a period from 1/1981 up to 6/1996 twelve publications (1994-1996), which have dealt the use of Ketamine for patients with chronic pain, are evaluated and discussed. The entire positive evaluation of the drug is based on the results of the studies under consideration. The studies investigating 88 cases are classified, i.e. seven studies are assigned to level 3, two studies to level 4, and three studies to level 5. A significant reduction of pain has been proven for patients with neuropathic pain by four cross-over-studies comparing the drug with placebo. However, observations have been restricted to a few hours after the administration of the drug. A positive effect of Ketamine as compared with opioids has been demonstrated by three studies, one of them with statistical significance. Positive long term results have been observed by two studies considering the subcutaneous and intravenous application of Ketamine (72-480 mg, daily) to 14 cancer pain patients, to whom opioids have been administered with insufficient effects before. A successful five-week-application (oral) of Ketamine has been described convincingly in a case report of a patient with postherpetic neuralgia. Two studies interpret the additional intrathecal administration of Ketamine to cancer patients as a possibility of either impeding the development of tolerance of the local anesthetic or reducing morphine requirements. Only one paper has dealt with the known side effects of Ketamine. Here, the therapy had to break off in two cases. In nine cases the side effects could be suppressed by Droperidol. For the future, research with more study power is necessary to establish Ketamine in the therapy of chronic pain.     

Deep-brain stimulation for the treatment of chronic pain

This article reviews recent studies on deep-brain stimulation. Topics covered include patient selection, target selection surgical technique, and long-term results. Several case reports illustrate successes and complications. The authors opinion on the value and future of this technique is also provided.     

Interdisciplinary treatment of chronic pain

Interdisciplinary treatment care must address more than the physical pathology. Chronic pain comprises a range of interdependent variables including biologic, cognitive, affective, behavioral, and social factors. This article discusses these psychosocial issues, as well as the four levels of pain management programs, and the characteristics and goals of interdisciplinary treatment. Finally, recent clinical studies demonstrating the efficacy and cost benefits of interdisciplinary pain management programs are reviewed.     

Topical agents for the treatment of chronic pain

Unlike systemic analgesics, topical analgesics exert their analgesic activity locally and without significant systemic absorption. This is in contrast to transdermal analgesics, which require systemic absorption for clinical benefit. The mechanism of action of a particular topical analgesic is unique to the specific medication being used as a topical analgesic. Topical analgesics have been studied in an increasing number of painful clinical conditions, and the results of some of these studies are summarized in this article. The potential role of topical analgesics acting peripherally in affecting the central processing of pain as well as painful states considered to be "central," not "peripheral," also are reviewed.     

Neurocognitive enhancement for the treatment of chronic pain

Chronic pain remains at epidemic levels in the United States, affecting approximately 20% of the population (Breivik et al., 2006). At present, treatments generally target symptom relief and seldom address improvements in quality of life and overall healing. Recent insights in neurobiology have demonstrated that chronic pain is a degenerative disease of cortical and sub-cortical structures (Tracy, 2008). Thus, treatments can be designed to enhance specific areas of the brain affected by chronic pain and, thereby, improve patients' cognitive and emotional abilities. For example, specific treatments can be designed that normalize function of frontal lobe areas negatively affected by the effects of chronic pain.     

Attention management as a treatment for chronic pain

Attention management is often included in cognitive‐behavioural treatments (CBT). The aim of this study was to evaluate the effects of attention management strategies in the treatment for chronic pain. The present pilot study consisted of six weekly 90‐min treatment sessions and was based on a CBT attention management manual describing techniques such as attention diversion, imagery and mindfulness exercises. The intended outcomes were reduction in pain‐related anxiety and hypervigilance to pain and decrease in pain impact of everyday life, measured by self‐report. Information was collected at baseline, pre‐treatment, post‐treatment, and at 3 and 6 months follow‐up. The results at the end of treatment, and at 3‐month follow‐up, show significant reductions in pain‐related anxiety, hypervigilance and interference of pain (effect sizes 0.40–0.90). Reduction in pain‐related interference and anxiety remained at the 6‐month follow‐up. The results indicate that attention control skills can be a useful method to reduce anxiety in the short term. Clinical implications of the results are discussed.     

Outpatient treatment of chronic pain groups for couples

The purpose of this study was to assess the impact of outpatient group treatment for chronic pain patients and their spouses on psychological symptomatology, marital adjustment, and locus of control. There was a significant improvement in mean scores on four of the seven measures pre- and post-treatment. This data suggests that group treatment can significantly reduce chronic pain related problems especially anxiety, depression, and interpersonal sensitivity for the patient as well as for the spouse. It also supports other findings for the effectiveness of brief group therapy programs for chronic pain patients. Although this study has several limitations the results warrant further investigation using control groups and a larger sample size.     

Help-seeking behaviour for the treatment of chronic pain

There are more people living with chronic pain than cardiovascular disease and cancer combined. Many people with chronic pain do not seek help from health professionals and suffer in silence for many years. Untreated chronic pain can lead to increased disability, increased risk of fall, depression, sleep deprivation, reduced quality of life and social isolation. The aim of this review is to determine the factors associated with help-seeking for chronic pain in an effort to highlight potential reasons why help may or may not be sought. A total of 23 studies were included in the review. On the whole the review has demonstrated that the most significant demographic and clinical factors associated with help-seeking were increasing age, female gender, pain severity and disability. Psychosocial factors included past help seeking, outcome expectancy, age-related beliefs, social cost and social influence. While the evidence presented appears promising, some conflicting results were found and methodological limitations were noted. Further research needs to examine the underlying determinants of help-seeking behaviour for chronic pain underpinned by theory. The information derived from such research will augment the development of a complex nursing intervention to improve help-seeking for chronic pain.     

Complementary medicine in chronic pain treatment

This chapter looks at therapies that are considered "alternative" to conventional medical approaches. A definition of "complementary and alternative" medicine is considered in the context of the complex and clinically challenging field of pain medicine. A rationale for studying unorthodox treatments of chronic pain is presented. The challenges of an evidence-based approach to incorporating complementary therapies are explored, and a brief survey of several commonly available complementary medicine therapies is provided.     

Predicting work status following interdisciplinary treatment for chronic pain.

The effectiveness of interdisciplinary treatments for chronic pain is well established. In general, these treatments decrease psychosocial distress and increase physical abilities. Further, return to work rates following interdisciplinary treatment tend to be quite high. Previous studies have highlighted a number of factors that individually influence return to work rates; however, there is a need for more comprehensive and unified models that allow an evaluation of the inter-relations among these factors. The present investigation examined how demographic and treatment outcome variables interacted to influence post-treatment return to work rates in a sample of individuals with chronic pain following interdisciplinary treatment. Results indicated that patient age, lifting ability, pain duration, depression level, and reported disability were individually related to return to work; however, when these variables were evaluated relative to one another, level of depression and patient age had the best ability to predict post-treatment work status. These results add to the literature by specifically highlighting post-treatment factors that best discriminate patients who had returned to work from those that had not. Furthermore, they provide evidence that general emotional distress is perhaps the most important predictor of work status following treatment.     

Alpha 2-adrenoceptor agonists for the treatment of chronic pain

The antinociceptive effect of alpha(2)-adrenoceptor agonists is mediated by activation of descending inhibiting noradrenergic systems, which modulates 'wide-dynamic-range' neurones. Furthermore, they inhibit the liberation of substance P and endorphines and activate serotoninergic neurones. Despite this variety of antinociceptive actions, there is still little experience with alpha(2)-adrenoceptor agonists as therapeutic agents for use in chronic pain syndromes. Studies in animals and patients have shown that the transdermal, epidural and intravenous administration of the alpha(2)-adrenoceptor agonist clonidine reduces pain intensity in neuropathic pain syndromes for periods varying from some hours up to 1 month. Patients suffering from lancinating or sharp pain respond best to this therapy. Topically applied clonidine (200-300 microg) relieves hyperalgesia in sympathetically maintained pain. Epidural administration of 300 microg clonidine dissolved in 5 ml NaCl 0.9 % has also been shown to be effective. In patients suffering from cancer pain tolerant to opioids, pain control has proved possible again with combinations of opioids and clonidine. In isolated cases clonidine has been administered epidurally at a dose of 1500 microg/day for almost 5 months without evidence for any histotoxic property of clonidine. Side effects often observed during administration of alpha(2)-adrenoceptor agonists are dry mouth, sedation, hypotension and bradycardia. Therapeutic interventions are usually not required.     

Ablative spinal cord surgery for the treatment of chronic pain

Percutaneous cordotomy can be a successful short-term procedure if performed by an experienced neurosurgeon. The procedure should be reserved for patients with intractable pain secondary to malignant disease that is resistant to conservative treatment and pain that is not of a dysesthetic type. Dorsal root entry zone (DREZ) lesions can be highly effective in eliminating certain previously intractable pain syndromes by eliminating the pathologic discharge of neurons in the dorsal horn following injury. DREZ surgery is of proven value in treating pain following brachial plexus avulsion injury and certain pain syndromes following spinal cord injury. DREZ lesions are less effective in treating postherpetic pain along with a higher prevalence of postoperative neurologic deficits, which may be due to the advanced age of patients suffering from this condition. This article reviews various aspects of anterolateral cordotomy and DREZ lesioning.     

Desmoid tumor complicating remobilization treatment for a chronic pain syndrome

The criteria for recommending an operant conditioning program for a patient with chronic pain include definable pain behavior. A thorough investigation of all organic factors that may contribute to pain is usually made prior to such treatment. This report describes a patient with chronic pain and mild cognitive deficits related to a truck accident who insidiously developed an extra-abdominal desmoid tumor. Desmoid tumors, which may develop after trauma, are associated with incidental connective tissue anomalies. They can be initially mistaken for fibrocytic nodules because they have a distribution similar to that in fibromyalgia. This patient's painful tumor was diagnosed while he was participating in a remobilization program. Subsequent resection and irradiation adversely affected rehabilitation goals and reinforced the patient's conviction that all his complaints were organically based.     

Drug infusions for the diagnosis and treatment of chronic pain

Diagnostic infusion therapy has several advantages over other routes of drug administration in the management of chronic pain. Although systemic side effects may occur, the procedure is relatively noninvasive and is generally well tolerated by patients. Infusion techniques have a potential use in the blinded evaluation of a patient’s response to a specific therapy, and thus may minimize placebo responses associated with the more invasive diagnostic nerve blocks. Infusion tests may be useful prognostic indicators of the potential efficacy of a class of oral drugs in a patient. This article reviews the scientific and clinical background behind the major classes of drugs used in diagnostic infusion testing, namely local anesthetics, opioids, and α-adrenergic blockers. Clinical application of these agents in the management of chronic pain also is outlined.