Pain
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Randomized Controlled Trial Clinical Trial
Regional sympathetic blockade in primary fibromyalgia.
Twenty-eight patients with primary fibromyalgia participated in the study. Eight patients received a stellate ganglion blockade with bupivacaine, and 14 days later an intravenous regional sympathetic blockade with guanethidine. The remaining patients served as controls and were randomly allocated to receive either a sham (placebo) injection with physiologic saline superficial to the stellate ganglion (n = 10) or bupivacaine intramuscularly (n = 10). ⋯ The guanethidine blockade reduced the number of TePs, but had no effect on rest pain. The reduction in pain and TePs produced by a sympathetic blockade may be due to an improvement in microcirculation. Sympathetic activity may, in some patients, contribute to the pathogenesis of primary fibromyalgia.
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These experiments quantitatively analyzed effects of electrical midbrain stimulation on a nociceptive hind limb flexion reflex in rats anesthetized with sodium pentobarbital. We recorded the force of isometric hind limb flexion withdrawal, and related flexor electromyographic (EMG) activity, elicited by noxious heat (42-54 degrees C, 10 sec) applied to the ventral hind paw. Several hind limb flexors including biceps femoris were active during the reflex. ⋯ Naloxone had little effect, while methysergide and phentolamine reduced PAG- and LRF-evoked reflex suppression in about one-half of the cases. Scopolamine largely reduced PAG- and LRF-evoked reflex suppression (in 8/9 and 4/6 rats, respectively). These results indicate that the flexion reflex is under parametrically but not pharmacologically distinct inhibitory midbrain controls.
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This study examined the extent to which the psychological variables of depression, anxiety, and helplessness predicted the pain behavior and functional status of 64 rheumatoid arthritis (RA) patients beyond what could be predicted on the basis of demographic and medical status variables. Pain behavior was evaluated using a standardized observation method, and functional status was assessed using a modified Health Assessment Questionnaire (MHAQ) and rheumatologists' ratings. Regression analyses revealed that a modified rheumatoid activity index and/or disease duration were significant predictors of levels of guarding, rigidity, and total pain behavior. ⋯ Age, disease duration and depression also were independent predictors of functional status ratings. Thus, depression had a significant relationship with physician ratings of functional status but not with patient self-reports of disability. Psychological factors not examined in this study that might influence RA pain behavior and self-reports of functional status are discussed.
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Test-retest reliability of a pain drawing instrument was investigated. Pain drawings of chronic pain patients (n = 51) were scored for percentage of total body surface in pain and location of pain. ⋯ The effect on reliability of age, gender and time-interval differences was investigated. The utility of the pain drawing instrument as a measure of extent of pain and location of pain over time is discussed.
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In order to overcome the cross-cultural semantic barriers related to the literal translation of the McGill Pain Questionnaire (MPQ) in non-English speaking areas, an Italian Pain Questionnaire (IPQ) has been developed, based on the 3 factorial structures proposed by Melzack and Torgerson: sensory, affective and evaluative. A group of 30 normal subjects (15 doctors and 15 university students) was used to define 5 anchor words of the intensity verbal scale by means of a visual analogue scale, and a 5-point Present Pain Intensity (PPI) verbal scale was derived. For the semantic key, a first group of 80 subjects (30 university students and patients, respectively, and 20 doctors) was asked to sort out appropriate pain descriptors from 203 pain-related words with the help of clinical literature and Italian dictionaries. ⋯ The final pain vocabulary was formed from those words, which reflected a statistically significant intensity change (P less than 0.05) within each group. The IPQ comprises 42 pain descriptors, distributed into 3 major classes (sensory, affective and evaluative) and 16 subclasses. It represents the most parsimonious, meaningful and idiomatic set of Italian pain descriptors, providing quantitative information that can be treated statistically, yet preserving a close structural parallel with the MPQ.