Pain
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Randomized Controlled Trial
Management of acute whiplash: A randomized controlled trial of multidisciplinary stratified treatments.
Acute whiplash is a heterogeneous disorder that becomes persistent in 40% to 60% of cases. Estimates of recovery have not changed in recent decades. This randomized, single-blind, controlled trial tested whether multidisciplinary individualized treatments for patients with acute whiplash (<4 weeks postinjury) could reduce the incidence of chronicity at 6 mo by 50% compared to usual care. ⋯ Analysis revealed no significant differences in frequency of recovery (NDI ≤ 8%) between pragmatic and usual care groups at 6 months (OR 95%, CI=0.55, 0.23-1.29), P=0.163) or 12 mo (OR 95%, CI=0.65, 0.28-1.47, P=0.297). There was no improvement in current nonrecovery rates at 6 mo (63.6%, pragmatic care; 48.8%, usual care), indicating no advantage of the early multiprofessional intervention. Baseline levels of pain and disability had a significant bearing on recovery both at 6 and 12 mo in both groups, suggesting that future research focus on finding early effective pain management, particularly for the subgroup of patients with initial high levels of pain and disability, towards improving recovery rates.
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Randomized Controlled Trial Multicenter Study
Endogenous opioid function mediates the association between laboratory-evoked pain sensitivity and morphine analgesic responses.
Predictors of responsiveness to opioid analgesic medications are not well understood. This study tested whether individual differences in endogenous opioid (EO) function are associated with analgesic responsiveness to morphine. In randomized, counterbalanced order over 3 sessions, 45 chronic low back pain participants and 31 healthy controls received an opioid antagonist (8 mg naloxone), morphine (0.08 mg/kg), or placebo. ⋯ These latter associations were significantly mediated by EO function for 4 of these 5 pain outcomes (all P values<0.05). In the laboratory-evoked pain context, opioid analgesic medications may supplement inadequate EO analgesia, with little incremental benefit in those with preexisting high EO function. Implications for personalized medicine are discussed.
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This study aimed to investigate the modulating effects of emotional context on pain perception in 16 patients with fibromyalgia syndrome (FMS) and 16 healthy control (HC) subjects. An infrared laser was used to apply individually adapted painful stimuli to the dorsum of the left hand. The emotional background of the painful stimuli was modulated by concurrent presentations of negative, neutral, and positive picture stimuli selected from the International Affective Picture System. ⋯ In contrast, FMS patients showed a quadratic trend for pain intensity ratings indicating a lack of pain reduction by the positive pictures. In addition, the FMS patients showed less activation in secondary somatosensory cortex, insula, orbitofrontal cortex, and anterior cingulate cortex during the positive picture pain trials. Our results suggest that fibromyalgia patients are less efficient in modulating pain by positive affect and may benefit less from appetitive events than healthy control subjects.