The journal of pain : official journal of the American Pain Society
-
Randomized Controlled Trial
Efficacy of home-based transcranial direct current stimulation over the primary motor cortex and dorsolateral prefrontal cortex in the disability due to pain in fibromyalgia: A factorial sham-randomized clinical study.
This randomized, double-blind, controlled clinical trial compared the effectiveness of home-based-(HB) active transcranial direct current stimulation (a-tDCS) over the left dorsolateral prefrontal cortex (l-DLPFC) or primary motor cortex (M1) with their respective sham-(s)-tDCS to determine whether a-tDCS would be more effective than s-tDCS in reducing pain and improving disability due to pain. The study included 102 patients with fibromyalgia aged 30 to 65 years old randomly assigned to 1 of 4 tDCS groups using a ratio of 2:1:2:1. The groups included l-DLPFC (a-tDCS, n = 34) and (s-tDCS, n = 17), or tDCS on the M1 (a-tDCS, n = 34) or (s-tDCS, n = 17). ⋯ PERSPECTIVE: These findings provide important insights: (1) HB-tDCS has effectively reduced pain scores and improved disability due to fibromyalgia. (2) The study provides evidence that HB-a-tDCS is a viable and effective therapeutic approach. (3) HB-a-tDCS over M1 improved the function of the descending pain inhibitory system and increased the heat pain threshold. Finally, our findings also emphasize that brain-derived neurotrophic factor, as an index of neuroplasticity, may serve as a valuable marker associated with changes in clinical pain measures. TRIAL REGISTRATION: Number NCT03843203.
-
Chronic musculoskeletal pain is often associated with lower socioeconomic status (SES). SES correlates with psychological and environmental conditions that could contribute to the disproportionate burden of chronic stress. Chronic stress can induce changes in global DNA methylation and gene expression, which increases risk of chronic pain. ⋯ Our main finding was that epigenetic aging mediated the associations of income and education with pain impact, as such the relationship between SES and pain outcomes may occur through potential interactions with the epigenome reflective of accelerated cellular aging. PERSPECTIVE: Socioeconomic status (SES) has previously been implicated in the pain experience. The present manuscript aims to present a potential social-biological link between SES and pain via accelerated epigenetic aging.
-
Nonspecific chronic low back pain (nCLBP) has been associated with nutrition. Yet, it is not clear how nutritional factors and nCLBP relate to one another. Therefore, the aim of the present study was to investigate differences in diet quality and dietary intake levels between nCLBP patients and healthy controls (HCs) and explore the association between nutritional factors and pain sensitivity in nCLBP. ⋯ Accordingly, pain sensitivity was mainly found to be positively associated with proinflammatory dietary intake. PERSPECTIVE: This study emphasizes the association between a proinflammatory diet and nCLBP. Among nCLBP patients, positive association between increased pain sensitivity and the proinflammatory potential of a diet, highlighting the potential for individualized pain management strategies and leading to the development of novel therapeutic methods.
-
People experience similarities between emotional feelings and bodily states on a daily basis, but both the magnitude and pervasiveness of this experiential similarity vary across individuals. Inspired by previous findings that chronic pain (CP) is characterized by strengthened pain-affect coupling and reduced interoceptive accuracy, we conducted 2 cross-sectional studies to examine whether patients with CP would exhibit less differentiated perception and mental representation of emotional feelings and bodily states. In study 1 (N = 500), patients with CP and healthy controls (HCs) completed a self-report questionnaire that asked explicitly about the perceived similarity between 5 basic emotion categories and a series of bodily states. ⋯ Our findings extend previous literature by demonstrating reduced discrimination between emotional and bodily experiences in CP that is not restricted to pain-related emotional and sensory experiences and may be related to a fundamentally less differentiated interoception. PERSPECTIVES: This study shows that patients with chronic pain have a profoundly less differentiated perception and implicit conceptualization of emotional feelings and bodily states, which appears to be associated with altered interoception. These findings may provide new perspectives on why they often experience a stronger pain-affect coupling.