Pain
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Randomized Controlled Trial
Non-invasive vagus nerve stimulation modulates trigeminal but not somatosensory perception: functional evidence for a trigemino-vagal system in humans.
Noninvasive vagus nerve stimulation (nVNS) is effective in several types of headache disorders. We sought to unravel the mechanism of how nVNS exhibits this efficacy. This study used a randomized, single-blind, sham-controlled, crossover design and comprised 3 projects with 3 independent cohorts of healthy participants. ⋯ Heart rate variability parameters did not change after nVNS. Our results provide functional evidence of a long hypothesized functional trigemino-vagal system in humans and may explain why nVNS is effective in some headache disorders but not in somatic pain disorders. Because unilateral nVNS modulated the trigeminal thresholds bilaterally, this effect is probably indirect through a central top-down mechanism.
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This study examined the efficacy of internet-delivered cognitive and behavioural interventions for adults with chronic pain AND explored the role of clinical and study characteristics as moderators of treatment effects. PubMed, Embase, PsycINFO, CENTRAL and CINAHL were searched to identify randomized controlled trials published up to October 2021. A meta-analysis of 36 studies (5778 participants) was conducted, which found small effect sizes for interference/disability (Hedges' g = 0.28; 95% confidence interval [CI] 0.21-0.35), depression ( g = 0.43; 95% CI 0.33-0.54), anxiety ( g = 0.32; 95% CI 0.24-0.40), pain intensity ( g = 0.27; 95% CI 0.21-0.33), self-efficacy ( g = 0.39; 95% CI 0.27-0.52) and pain catastrophizing ( g = 0.31; 95% CI 0.22-0.39). ⋯ No differences were found between treatments based on traditional cognitive behaviour therapy vs acceptance and commitment therapy. Sample size, study year, and overall risk of bias (Cochrane rating) did not consistently moderate treatment effects. Overall, the results support the use of internet-delivered cognitive and behavioural interventions as efficacious and suggest guided interventions are associated with greater clinical gains for several key pain management outcomes.
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Randomized Controlled Trial
Effects of Hypnosis vs Mindfulness Meditation vs Education on Chronic Pain Intensity and Secondary Outcomes in Veterans: A Randomized Clinical Trial.
Effective, rigorously evaluated nonpharmacological treatments for chronic pain are needed. This study compared the effectiveness of training in hypnosis (HYP) and mindfulness meditation (MM) with an active education control (ED). Veterans (N = 328) were randomly assigned to 8 manualized, group-based, in-person sessions of HYP (n = 110), MM (n = 108), or ED (n = 110). ⋯ No significant differences on outcomes between HYP and MM were detected at any time point. This study suggests that all 3 interventions provide posttreatment benefits on a range of outcomes, but the benefits of HYP and MM continue beyond the end of treatment, while the improvements associated with ED dissipate over time. Future research is needed to determine whether the between-group differences that emerged posttreatment are reliable, whether there are benefits of combining treatments, and to explore moderating and mediating factors.
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The interest and the rationale for meaningful engagement of patients as partners in clinical trials of pain treatments has been increasing. No specific guidance on patient engagement for pain research studies currently exists; thus, the goal of this narrative review was to provide a historical perspective and a current evaluation of the literature on engaging patients as partners in clinical studies in general and in pain-related studies more specifically. ⋯ We provided an overview on key practices of patient recruitment and engagement as partners in clinical research and highlighted the perceived benefits and challenges of such partnerships. We summarized factors that can facilitate or hinder meaningful patient engagement in clinical trials of pain treatments and outlined gaps that future research should address to optimize patient-centered clinical research.
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Randomized Controlled Trial
How do placebo effects contribute to mindfulness-based analgesia? Probing acute pain effects and interactions using a randomized balanced placebo design.
Recent sham-controlled studies suggest placebo effects contribute to acute pain relief after mindfulness interventions. However, the specific effects of mindfulness processes and their interaction with placebo effects remain unclear. This study aimed to characterize the role of mindfulness and placebo processes underlying mindfulness-based pain attenuation. ⋯ These findings suggest a lack of specific effects of mindfulness and instruction on acute pain. Nonetheless, participants' expectancies and beliefs about the treatment they received did predict pain relief. Together with the overall improvement after any intervention, these findings suggest that expectancy and belief may play a stronger role in attenuating acute pain in novices following brief mindfulness interventions than the actual mindfulness-specific processes or instructions delivered.