The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Qigong or Yoga versus no intervention in older adults with chronic low back pain - a randomized controlled trial.
The aim of this study was to assess the effectiveness of the reduction of chronic lower back pain in older adults using either yoga classes or qigong classes compared with no intervention. Older adults (65 years of age and older) with chronic low back pain were enrolled in and randomly allocated to: 1) yoga (24 classes, 45 minutes each, during 3 months), 2) qigong (12 classes, 90 minutes each, during 3 months), or 3) a control group who received no additional intervention. The pain intensity item of the Functional Rating Index after 3 months was used as primary outcome parameter. A total of 176 patients were randomized (n = 61 yoga, n = 58 qigong, n = 57 control; mean age 73 ± 5.6 years, 89% female). The mean adjusted pain intensity after 3 months was 1.71 for the yoga group (95% confidence interval [CI], 1.54-1.89), 1.67 for the qigong group (95% CI, 1.45-1.89), and 1.89 for no intervention (95% CI, 1.67-2.11). No statistically significant group differences were observed. Possible explanations for this lack of pain relief might include the ineffectiveness of interventions, inappropriate outcomes, or differences in pain perception and processing in older adults. ⋯ The aim of this study was to assess the effectiveness of the reduction of chronic lower back pain in older adults using either yoga classes or qigong classes compared with no intervention. This 3-armed randomized trial with 176 older adults showed that yoga and qigong were not superior to no treatment in reducing pain and increasing quality of life.
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The risk for misuse of opioid medications is a significant challenge in the management of chronic pain. The identification of those who may be at greater risk for misusing opioids is needed to facilitate closer monitoring of high-risk subgroups, and may help to identify therapeutic targets for mitigating this risk. The aim of this study was to examine whether distress intolerance-the perceived or actual inability to manage negative emotional and somatic states-was associated with opioid misuse in those with chronic pain. A sample of 51 participants prescribed opioid analgesics for chronic back or neck pain were recruited for a 1-time laboratory study. Participants completed measures of distress intolerance and opioid misuse, and a quantitative sensory testing battery. Results suggested that distress intolerance was associated with opioid misuse, even controlling for pain severity and negative affect. Distress intolerance was not associated with pain severity, threshold, or tolerance, but was associated with self-reported anxiety and stress after noxious stimuli. This study found robust differences in distress intolerance between adults with chronic pain with and without opioid medication misuse. Distress intolerance may be a relevant marker of risk for opioid misuse among those with chronic pain. ⋯ This study demonstrated that distress intolerance was associated with opioid misuse in adults with chronic pain who were prescribed opioids. Distress intolerance can be modified with treatment, and thus may be relevant not only for identification of risk for opioid misuse, but also for mitigation of this risk.
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Chemotherapy-induced peripheral neuropathy (CIPN) is a disruptive and persistent side effect of cancer treatment with paclitaxel. Recent reports showed that paclitaxel treatment results in the activation of Toll-like receptor 4 (TLR4) signaling and increased expression of monocyte chemoattractant protein 1 (MCP-1) in dorsal root ganglion cells. In this study, we sought to determine whether an important consequence of this signaling and also a key step in the CIPN phenotype was the recruitment and infiltration of macrophages into dorsal root ganglia (DRG). Here, we show that macrophage infiltration does occur in a time course that matches the onset of the behavioral CIPN phenotype in Sprague-Dawley rats. Moreover, depletion of macrophages by systemic administration of liposome-encapsulated clodronate (clophosome) partially reversed behavioral signs of paclitaxel-induced CIPN as well as reduced tumor necrosius factor α expression in DRG. Intrathecal injection of MCP-1 neutralizing antibodies reduced paclitaxel-induced macrophage recruitment into the DRG and also blocked the behavioral signs of CIPN. Intrathecal treatment with the TLR4 antagonist lipopolysaccharide-RS (LPS-RS) blocked mechanical hypersensitivity, reduced MCP-1 expression, and blocked the infiltration of macrophages into the DRG in paclitaxel-treated rats. The inhibition of macrophage infiltration into DRG after paclitaxel treatment with clodronate or LPS-RS prevented the loss of intraepidermal nerve fibers (IENFs) observed after paclitaxel treatment alone. These results are the first to indicate a mechanistic link such that activation of TLR4 by paclitaxel leads to increased expression of MCP-1 by DRG neurons resulting in macrophage infiltration to the DRG that express inflammatory cytokines and the combination of these events results in IENF loss and the development of behavioral signs of CIPN. ⋯ This paper shows that activation of innate immunity by paclitaxel results in a sequence of signaling events that results in the infiltration of the dorsal root ganglia by activated macrophages. Macrophages appear to drive the development of behavioral hypersensitivity and the loss of distal epidermal nerve fibers, and hence play an important role in the mechanism of paclitaxel-related neuropathy.
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Little is known about the factors associated with pain-related outcomes in older adults. In this observational study, we sought to identify patient factors associated with improvements in pain intensity in a national cohort of older veterans with chronic pain. We included 12,924 veterans receiving treatment from the Veterans Health Administration with persistently elevated numeric rating scale scores in 2010 who had not been prescribed opioids in the previous 12 months. We examined: 1) percentage decrease over 12 months in average pain intensity scores relative to average baseline pain intensity score; and 2) time to sustained improvement in average pain intensity scores, defined as a 30% reduction in 3-month scores compared with baseline. Average relative improvement in pain intensity scores from baseline ranged from 25% to 29%; almost two-thirds met criteria for sustained improvement during the 12-month follow-up period. In models, higher baseline pain intensity and older age were associated with greater likelihood of improvement in pain intensity, whereas Veterans Affairs service-connected disability, mental health, and certain pain-related diagnoses were associated with lower likelihood of improvement. Opioid prescription initiation during follow-up was associated with lower likelihood of sustained improvement. The findings call for further characterization of heterogeneity in pain outcomes in older adults as well as further analysis of the relationship between prescription opioids and treatment outcomes. ⋯ This study identified factors associated with improvements in pain intensity in a national cohort of older veterans with chronic pain. We found that older veterans frequently show improvements in pain intensity over time, and that opioid prescriptions, mental health, and certain pain diagnoses are associated with lower likelihood of improvement.
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Despite a fundamental interest in the relationship between structure and function, the relationships between measures of white matter microstructural coherence and functional brain responses to pain are poorly understood. We investigated whether fractional anisotropy (FA) in 2 white matter regions in pathways associated with pain is related to the functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) response to thermal stimulation. BOLD fMRI was measured from 16 healthy male subjects during painful thermal stimulation of the right arm. Diffusion-weighted images were acquired for each subject and FA estimates were extracted from the posterior internal capsule and the cingulum (cingulate gyrus). These values were then included as covariates in the fMRI data analysis. We found BOLD response in the midcingulate cortex (MCC) to be positively related to FA in the posterior internal capsule and negatively related to FA in the cingulum. Our results suggest that the MCC's involvement in processing pain can be further delineated by considering how the magnitude of the BOLD response is related to white matter microstructural coherence and to subjective perception of pain. Considering relationships to white matter microstructural coherence in tracts involved in transmitting information to different parts of the pain network can help interpretation of MCC BOLD activation. ⋯ Relationships between functional brain responses, white matter microstructural coherence, and subjective ratings are crucial for understanding the role of the MCC in pain. These findings provide a basis for investigating the effect of the reduced white matter microstructural coherence observed in some pain disorders on the functional responses to pain.