The journal of pain : official journal of the American Pain Society
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Fibromyalgia (FM) is a chronic pain condition marked by centrally mediated augmentation of pain and sensory processes. Skepticism has marked the history of this condition, but more recent study has identified neurobiological underpinnings supporting many of the symptoms associated with this condition. Early research in FM had unprecedented latitude within the rheumatology community to borrow heavily from theory and methods being applied in chronic pain research more generally. These insights facilitated rapid advances in FM research, not the least of which was the abandonment of a peripheral focus in favor of studying central mechanisms associated with central augmentation. Currently, rapid-paced discovery is taking place in FM genetics, patient assessment, new therapeutic targets, and novel methods of treatment delivery. Such insights are not likely to be limited in application just to FM and could have relevance to the broader field of pain research as well. ⋯ This manuscript reviews the history of FM and its diagnosis, evidence supporting central augmentation of pain in FM, potential mechanisms of central augmentation, current approaches to integrated care of FM, and areas of active collaboration between FM research and other chronic pain conditions.
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Cross-sectional studies have suggested a relationship between respiratory disorders, incontinence, gastrointestinal symptoms, and back pain. However, longitudinal data are lacking. This study aimed to evaluate whether these disorders increase risk for the development of back pain. A total of 2943 younger, 2298 mid-age, and 2258 older women from the Australian Longitudinal Study on Women's Health who reported no back pain during the preceding 12 months were followed for 4, 2, and 3 years, respectively. Crude and adjusted associations between the development of back pain and changes in the presence of incontinence, breathing difficulty, and gastrointestinal symptoms were assessed with logistic regression. Women with preexisting incontinence (prevalence ratios [PR]: 1.26 to 1.46) and gastrointestinal symptoms (PR: 1.24 to 1.44) and women who developed breathing problems (PR: 1.63 to 2.11) were more likely to develop back pain than women without such problems. Menstrual pain and allergy were also associated with back pain development. Consistent with predictions from physiological data, this study provides novel evidence that the presence and/or development of incontinence, respiratory problems, and gastrointestinal symptoms are associated with the development of back pain. This highlights the importance of comorbidities and suggests opportunities for future preventative interventions. ⋯ This study demonstrates that women with incontinence, respiratory disorders, and gastrointestinal symptoms have increased risk for the development of back pain. Evidence of compromised control of the spine in people with incontinence and respiratory disorders and the potential for viscerosomatic hyperalgesia in people with gastrointestinal symptoms may provide physiological explanations for these findings.
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The Original Pain Recall Assessment form (OPRA) is a technique that allows people to report on their pattern of pain over time. This investigation reports on the psychometric properties of the OPRA. Our results are analyzed from a cognitive-behavioral perspective. Correlation analyses on data from 72 respondents indicate that participants' patterns of symptoms recalled on the OPRA over a 28-day period were positively related to previous daily diary reports. Symptom ratings on an adapted OPRA showed different patterns of association with past symptom reports in distinct subgroups. A hypothesized, primacy recency effect of the diary procedure on symptom recall was supported. Statistics designed for use with paired, ordered categorical data showed acceptable agreement between diary ratings and those made at recall. In a basic research setting, the form offers the potential to evaluate individual correlates of pain recall. It can also be used at an individual level to describe the character of disagreement with prior ratings. ⋯ This article presents the psychometric properties of a pain-assessment procedure. Our results suggest that the way people recall their symptoms is related to cognitive, emotional, and behavioral correlates of the pain experience. The importance of individual differences in overt and covert behaviors and their relationship to persistent pain complaints warrants further attention.
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Randomized Controlled Trial
L2 spinal nerve-block effects on acute low back pain from osteoporotic vertebral fracture.
Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may feel diffuse nonlocalized pain in the back, the lateral portion of the trunk, and the area surrounding the iliac crest. The pattern of sensory innervation of vertebral bodies remains unclear. Some sensory nerves from the L2 and L5 vertebral bodies may enter the paravertebral sympathetic trunks and reach the L2 dorsal root ganglion. Our randomized controlled study was to clarify the effect of L2 spinal nerve block on low back pain originating from acute osteoporotic lumbar vertebral fracture. Patients with low back pain originating from acute L3 or L4 osteoporotic vertebral fractures received a spinal nerve root block (L2 block group, n = 30) or subcutaneous injection (control, n = 30). Both groups received 1.5 mL of 1% lidocaine. The visual analog scale score, Roland Morris Disability Questionnaire, and Short Form questionnaire were examined before and after treatment. In both groups, spinal nerve blocks were significantly effective in alleviating low back pain (P < .05). One hour, 1 week, and 2 weeks after treatment, the visual analog scale score improved more in the L2 block group than in the control group (P < .05). From 1 month to 4 months after treatment, there were no significant differences in the pain scores between groups (P > .05). We conclude that L2 spinal nerve block for acute L3 or L4 osteoporotic vertebral body fracture was effective for 2 weeks, but it had no long-term effects on pain and social function. ⋯ L2 spinal nerve block treatment for L3 or L4 osteoporotic vertebral body fracture was effective. This results suggest that the L2 dorsal root ganglion may innervate the L3 and L4 vertebral bodies in humans. L2 spinal nerve block for lumbar osteoporotic vertebral fracture may be a useful strategy to treat acute low back pain.
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Bodily representations of the primary somatosensory (SI) cortex are constantly modified according to sensory input. Increased input due to training as well as loss of input due to deafferentation are reflected as changes in the extent of cortical representations. Recent studies in complex regional pain syndrome (CRPS) patients have indicated that the chronic pain itself is associated with cortical reorganization. However, it is unclear whether the observed reorganization is specific for CRPS or if it can be detected also in other types of chronic pain. We therefore searched for signs of cortical reorganization in a group of 8 patients who suffered from chronic pain associated with herpes simplex virus infections. The pain was widespread but restricted to unilateral side of the body and included the upper limb. We recorded neuromagnetic responses to tactile stimulation of fingers of both hands in patients and in a group of healthy, matched control subjects. In the patients, the distance between the thumb (D1) and little finger (D5) representations in SI cortex was statistically significantly smaller in the hemisphere contralateral to painful side than in the hemisphere contralateral to healthy side. In the control subjects, the D1-D5 distance was the same in both hemispheres. ⋯ The present results indicate that cortical reorganization occurs in chronic neuropathic pain patients even without peripheral nerve damage. It is possible that cortical reorganization is related to chronic pain, regardless of its etiology. Causality between reorganization and chronic pain should be examined further to develop therapeutic approaches for chronic pain.