The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial Comparative Study
The pain quality assessment scale: assessment of pain quality in carpal tunnel syndrome.
The Neuropathic Pain Scale (NPS) is a valid measure of the pain qualities and perceived depth of neuropathic pain. However, it does not include a number of pain qualities commonly seen in some neuropathic and non-neuropathic pain conditions. To address this limitation, additional items were added to the NPS to create a 20-item measure (Pain Quality Assessment Scale, PQAS) that would be even more useful for assessing neuropathic pain and also would be used to assess pain qualities associated with non-neuropathic pain. To evaluate the responsivity of the PQAS items to pain treatment, secondary analyses were conducted on data from a trial that compared the efficacy of lidocaine patch 5% versus a single steroid injection in 40 patients with carpal tunnel syndrome. Statistically significant (P < .0025) decreases in 10 of the 20 PQAS pain descriptor ratings occurred with both treatments, and 8 ratings showed nonsignificant trends (.0025 < P < .05) for decreasing before treatment to after treatment. No significant differences were found between the 2 treatment conditions on any of the items. The results support the validity of the PQAS items for assessing the effects of pain treatment on pain qualities of carpal tunnel syndrome. ⋯ Clinical trials that include measures of pain qualities can be used to identify the effects of treatments on distinct pain qualities. Measures such as the PQAS can potentially be used to help clinicians target analgesics more efficiently.
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Randomized Controlled Trial
Use of the chronic pain coping inventory to assess older adults' pain coping strategies.
Little is known about the strategies that older adults use to cope with persistent pain. The purpose of this study was to describe strategies used by older, retirement community-dwelling adults to cope with persistent, noncancer pain, as assessed by the Chronic Pain Coping Inventory (CPCI), to examine the associations of these strategies with disability and depression, and to compare the 65-item and 42-item versions of the CPCI in this population. Two hundred fifty residents of 43 retirement communities in the Pacific Northwest completed baseline measures for a randomized controlled trial of a pain self-management intervention, including the CPCI and measures of demographics, comorbidity, pain-related disability, and depression. The most frequently reported strategies, as assessed by the CPCI, were Task Persistence, Pacing, and Coping Self-Statements. The least frequently used strategies were Asking for Assistance and Relaxation. Regression analyses demonstrated that coping strategies explained 26%, 19%, and 18% additional variance in physical disability, depression, and pain-related interference, respectively, after controlling for age, gender, comorbidity, and pain intensity. Internal consistency for most CPCI-65 and CPCI-42 subscales was adequate. This study clarifies strategies used by older adults to cope with persistent pain and provides preliminary validation of the CPCI in this population. ⋯ Findings from this study on pain coping strategies in older adults might suggest potentially useful coping strategies clinicians could explore with individual patients. Investigators can use study findings to design trials of interventions to help older adults cope more effectively with pain.
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Fibromyalgia syndrome (FMS) is more prevalent in women than in men. The skewed sex distribution in the prevalence has prompted questions of if and how sex hormones may be involved in the pathophysiology of FMS. In this study, we evaluated the levels of sex hormones and pain sensitivity at different phases of a menstrual cycle in regularly menstruating women with FMS relative to age-matched healthy women. Participants (n = 74 in each group) underwent a 9-day urine test to identify the date of ovulation. Three laboratory visits were scheduled to ascertain the varying levels of estrogen (E) and progesterone (P): Late-follicular phase (high E, low P); mid-luteal phase (high E, high P); and perimenstrual phase (low E, low P). At each visit, blood was drawn and ischemic pain testing was performed. The groups did not differ in the fluctuation of luteal hormone, follicular-stimulating hormone, E, and testosterone across a menstrual cycle. FMS patients showed slightly elevated P levels during the mid-luteal phase relative to healthy women but levels were within the normal range. Women with FMS showed consistently lower pain thresholds and tolerance relative to healthy women throughout the menstrual cycle. Pain threshold at the late follicular phase was modestly related to the P level. The results suggest that the disproportionate prevalence of females with FMS is not likely to be attributable to hormonal factors. Furthermore, the role of sex hormones in pain sensitivity for both FMS and healthy women seems to be limited. ⋯ Normally menstruating women with FMS and healthy women do not seem to show fluctuating threshold and tolerance to the ischemic pain test. The role of sex hormones in the hyperalgesia of FMS appears limited.
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The activation of spinal cord microglia and astrocytes after peripheral nerve injury or inflammation contributes to behavioral hypersensitivity. The contribution of spinal cord glia to mechanical hypersensitivity after hind paw incision has not been investigated previously. Male Sprague-Dawley rats underwent a unilateral plantar hind paw incision, and the development of mechanical hypersensitivity was assessed by using von Frey filaments. The activation of spinal cord microglia and astrocytes was measured 1, 2, 3, and 5 days after hind paw incision by using immunohistochemistry. The glial activation inhibitor, fluorocitrate, was administered intrathecally 24 hours after hind paw incision to determine glial involvement in mechanical hypersensitivity. Hind paw incision induced an activation of spinal astrocytes ipsilateral to incision within 24 hours. Both microglia and astrocytes reached a maximum activation 3 days after hind paw incision. Fluorocitrate produced a dose-dependent reduction in mechanical hypersensitivity when administered 24 hours after hind paw incision. Spinal cord glial activation contributes to the mechanical hypersensitivity that develops after hind paw incision. ⋯ Hind paw incision produces mechanical hypersensitivity that can be alleviated with the inhibition of spinal cord glia. Our results suggest that the activation of spinal cord astrocytes within 24 hours of incision contributes to mechanical hypersensitivity. Therefore, spinal cord astrocytes might represent a novel target for the treatment of postoperative pain.