Pain
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Randomized Controlled Trial Multicenter Study Comparative Study
Practice, practitioner, or placebo? A multifactorial, mixed-methods randomized controlled trial of acupuncture.
The nonspecific effects of acupuncture are well documented; we wished to quantify these factors in osteoarthritic (OA) pain, examining needling, the consultation, and the practitioner. In a prospective randomised, single-blind, placebo-controlled, multifactorial, mixed-methods trial, 221 patients with OA awaiting joint replacement surgery were recruited. Interventions were acupuncture, Streitberger placebo acupuncture, and mock electrical stimulation, each with empathic or nonempathic consultations. ⋯ Needle and nonneedle placebos are equivalent. An unknown characteristic of the treating practitioner predicts outcome, as does the patient's belief (independently). Beliefs about treatment veracity shape how patients self-report outcome, complicating and confounding study interpretation.
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Multicenter Study
Association of pain with behavioral and psychiatric symptoms among nursing home residents with cognitive impairment: results from the SHELTER study.
The etiology of behavioral and psychiatric symptoms is generally considered to be multifactorial, and these symptoms often indicate a need for care or assistance, which may include the presence of uncontrolled pain. The aim of this cross-sectional study was to assess the association of pain with behavioral and psychiatric symptoms in a population of nursing home (NH) residents with cognitive impairment in Europe. Data are from the SHELTER project, which contains information on NH residents in 8 countries. ⋯ A borderline inverse association was observed with wandering (OR 0.74; 95% CI 0.55-1.00). In conclusion, this cross-sectional study provides evidence from a large sample of frail elderly showing an association between pain and behavioral and psychiatric symptoms. Treatment models that put together assessment and treatment of pain and evaluate their effect on behavioral and psychiatric symptoms are needed.
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Murine models of osteoarthritis (OA) provide a potentially powerful tool to elucidate mechanisms responsible for OA pain. However, few studies have examined pain behaviours in relevant OA models in mice. We have therefore characterized the time course and pharmacological sensitivities of pain-related behaviours in a model of OA in C57Bl/6 mice induced by partial medial meniscectomy. ⋯ In contrast, other analgesic drugs (paracetamol, gabapentin, and tramadol) had selective effects on only 1 or 2 modalities. Pain levels fluctuated during the second phase, with transient periods of reduced pain. At these times, underlying hypersensitivities could be unmasked by administration of naloxone, indicating that reduced pain was due to endogenous opioids.
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Comparative Study
Neural mechanisms mediating the effects of expectation in visceral placebo analgesia: an fMRI study in healthy placebo responders and nonresponders.
This functional magnetic resonance imaging study analysed the behavioural and neural responses during expectation-mediated placebo analgesia in a rectal pain model in healthy subjects. In N=36 healthy subjects, the blood oxygen level-dependent (BOLD) response during cued anticipation and painful rectal stimulation was measured. Using a within-subject design, placebo analgesia was induced by changing expectations regarding the probability of receiving an analgesic drug to 0%, 50%, and 100%. ⋯ Compared with nonresponders, responders demonstrated greater placebo-induced decreases in activation of dorsolateral prefrontal cortex during anticipation and in somatosensory cortex, posterior cingulate cortex, and thalamus during pain. In conclusion, the expectation of pain relief can substantially change perceived painfulness of visceral stimuli, which is associated with activity changes in the thalamus, prefrontal, and somatosensory cortices. Placebo analgesia constitutes a paradigm to elucidate psychological components of the pain response relevant to the pathophysiology and treatment of chronic abdominal pain.
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Randomized Controlled Trial Multicenter Study
Group cognitive behavioural interventions for low back pain in primary care: extended follow-up of the Back Skills Training Trial (ISRCTN54717854).
Group cognitive behavioural intervention (CBI) is effective in reducing low back pain and disability over a 12-month period, in comparison to best practice advice in primary care. The aim was to study the effects of this CBI beyond 12 months. We undertook an extended follow-up of our original randomised, controlled trial of a group CBI and best practice advice in primary care, in comparison to best practice advice alone. ⋯ There was no between-group difference in Modified von Korff Scale pain outcomes. The results suggest that the effects of a group CBI are maintained up to an average of 34 months. Although pain improves in response to best practice advice, longer-term recovery of disability remains substantially less.