The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Hydrocortisone differentially affects reinstatement of pain-related responses in patients with chronic back pain and healthy volunteers.
Despite the crucial role of effective and sustained extinction of conditioned pain-related fear in cognitive-behavioral treatment approaches for chronic pain, experimental research on extinction memory retrieval in chronic pain remains scarce. In healthy populations, extinction efficacy of fear memory is affected by stress. Therefore, we investigated the effects of oral hydrocortisone administration on the reinstatement of pain-related associations in 57 patients with non-specific chronic back pain (CBP) and 59 healthy control (HC) participants in a differential pain-related conditioning paradigm within a placebo-controlled, randomized, and double-blind design. ⋯ Our findings corroborate previous evidence of stress-induced effects on extinction efficacy and reinstatement of fear memory in HCs, extending them into the pain context, and call for more research to clarify the role of stress in fear extinction and return of fear phenomena possibly contributing to treatment failure in chronic pain treatment. PERSPECTIVE: Opposing effects in HCs and patients with non-specific CBP may be associated with changes in the patients' stress systems. These findings could be of relevance to optimizing psychological, extinction-based treatment approaches.
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Randomized Controlled Trial
Bilateral corticomotor reorganisation and symptom development in response to acute unilateral hamstring pain: A randomised, controlled study.
Accumulating evidence demonstrates that pain induces adaptations in the corticomotor representations of affected muscles. However, previous work has primarily investigated the upper limb, with few studies examining corticomotor reorganization in response to lower limb pain. This is important to consider, given the significant functional, anatomical, and neurophysiological differences between upper and lower limb musculature. ⋯ These effects persisted for at least 75 minutes after pain resolution. PERSPECTIVE: These findings suggest that individual patterns of corticomotor reorganization may contribute to ongoing functional deficits of either limb following acute unilateral lower limb pain. Further research is required to assess these adaptations and the possible long-term implications for rehabilitation and reinjury risk in cohorts with acute hamstring injury.
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A variety of evidence-based psychosocial treatments now exist for chronic pain. However, on average, effect sizes have tended to be modest and there is a high degree of heterogeneity in treatment response. In this focus article, we explore the potential role that therapist quality in delivering treatment may have in accounting for a degree of this variability in outcome. ⋯ PERSPECTIVE: Therapist quality in the delivery of psychosocial treatments for chronic pain has rarely been assessed in clinical trials. We propose that therapist quality indicators are an under-studied mechanism that potentially contributes to the heterogeneity of treatment outcomes. We provide recommendations for assessing and reporting on therapist quality in future trials.
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We aimed to quantify the prospective association between bullying and physical pain in a population-based cohort of adolescents. We assessed 4,049 participants of the 10 and 13 years waves of the Generation XXI birth cohort study in Portugal. Pain history was collected using the Luebeck pain screening questionnaire. ⋯ No differences were seen for the remaining bullying profiles or sensory measures. Our findings suggest that bullying may have long-term influence on the risk of chronic musculoskeletal pain and may interfere with responses to painful stimuli. PERSPECTIVE: We found prospective evidence that bullying victimization in youth: 1) is more likely to lead to negative reported pain experiences than the reverse, 2) may have long-term influence on adverse pain experiences, and 3) may contribute to pain phenotypes partly by interfering with somatosensory responses to painful stimuli.
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Randomized Controlled Trial
Understanding the role of expectancy, anticipatory anxiety and attention bias in nocebo hyperalgesia: A gaze-contingent attention bias modification study.
Nocebo effects in pain (nocebo hyperalgesia) have been thoroughly researched, and negative expectancies have been proposed as a key factor in causing nocebo hyperalgesia. However, little is known about the psychological mechanisms by which expectations exacerbate the perception of pain. A potential mechanism that has been proposed within wider pain research is pain-related attention. ⋯ The study shows that expectancy can trigger anticipatory anxiety that exacerbates nocebo hyperalgesia. Further, successful AB training towards pain heightens nocebo hyperalgesia. These findings identify candidate psychological factors to target in minimizing nocebo hyperalgesia.