The journal of pain : official journal of the American Pain Society
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Controlled Clinical Trial
Reduction of pain and spinal nociceptive transmission by working memory is load dependant.
Working memory (WM) engagement produces pain inhibition. However, it remains unclear whether higher WM load increases this effect. The aim of this study was to investigate the interaction between WM load and pain inhibition by WM and examine the contribution of cerebrospinal mechanism. ⋯ NFR inhibition by WM suggests that inhibition of pain by WM depends, at least in part, on cerebrospinal mechanism. PERSPECTIVE: This behavioral and electrophysiological study shows that engaging in a cognitive task reduces pain by decreasing spinal nociceptive transmission, depending on task difficulty. These findings may yield better nonpharmacological pain therapies based on individual differences in working memory performance and capacity as well as several factors that regulate working memory.
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A growing body of evidence supports the modulation of pain by light exposure. As such, phototherapy is being increasingly utilized for the management of a variety of pain conditions. The modes of delivery, and hence applications of phototherapy, vary by wavelength, intensity, and route of exposure. ⋯ The mechanisms of photobiomodulation of pain presented in this review provide a foundation in furtherance of exploration of the utility of phototherapy as a tool in the management of pain. PERSPECTIVE: This review synopsizes the pathways and mechanisms through which light modulates pain and the therapeutic utility of different colors and exposure modalities of light on pain. Recent advances in photobiomodulation provide a foundation for understanding this novel treatment for pain on which future translational and clinical studies can build upon.
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Randomized Controlled Trial
Effects of dry needling on muscle stiffness in latent myofascial trigger points: a randomized controlled trial.
The aim of this study was to analyze the effects of dry needling (DN) in upper trapezius latent trigger points (LTrPs) on muscle stiffness. A total of 51 recreational physically active subjects with LTrPs in the upper trapezius volunteered to participate and were randomly divided into a DN-group (n = 27) and a sham-DN group (n = 24). Volunteers received 1-session of DN or placebo treatment. ⋯ There was a progressive decrease in post-needling soreness compared to pain during needling of 33.13 ± 21.31% at 30-min, 80.92 ± 10.06% at 24-hours, and a total decrease in post-needling soreness in all participants at 72-hours. DN therapy is effective in reducing short-term muscle stiffness and increasing the PPT in volunteers with LTrPs in the upper trapezius after a treatment session. PERSPECTIVE: This study found that one session of DN intervention in latent trigger points of the upper trapezius muscle reduced muscle stiffness and the pressure pain threshold for the dry needling group compared to the sham dry needling group.
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Chronic pain and suicidal behavior are prevalent in adolescents. This longitudinal study examined the associations between pain symptoms and suicidal behavior in adolescents. A total of 7,072 adolescents participated in a follow-up study of behavior and health in Shandong, China. ⋯ PERSPECTIVE: This article presents the prospective associations of frequent pain symptoms with suicidal behavior in adolescents. Frequent pain was associated with a 50-70% increased risk of suicidal behavior 1 year later. The finding underscores the importance of pain assessment and treatment in comprehensive suicide prevention efforts in adolescents.
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Nociceptor Overexpression of NaV1.7 Contributes to Chronic Muscle Pain Induced by Early-Life Stress.
Adult rats previously submitted to neonatal limited bedding (NLB), a model of early-life stress, display muscle mechanical hyperalgesia and nociceptor hyperexcitability, the underlying mechanism for which is unknown. Since voltage-gated sodium channel subtype 7 (NaV1.7) contributes to mechanical hyperalgesia in several preclinical pain models and is critical for nociceptor excitability, we explored its role in the muscle hyperalgesia exhibited by adult NLB rats. Western blot analyses demonstrated increased NaV1.7 protein expression in L4-L5 dorsal root ganglia (DRG) from adult NLB rats, and antisense oligodeoxynucleotide (AS ODN) targeting NaV1.7 alpha subunit mRNA attenuated the expression of NaV1.7 in DRG extracts. ⋯ AS ODN knockdown of extracellular signal-regulated kinase 1/2, which enhances NaV1.7 function, also inhibited mechanical hyperalgesia in NLB rats. Our results support the hypothesis that overexpression of NaV1.7 in muscle nociceptors play a role in chronic muscle pain induced by early-life stress, suggesting that NaV1.7 is a target for the treatment of chronic muscle pain. PERSPECTIVE: We demonstrate that early-life adversity, induced by exposure to inconsistent maternal care, produces chronic muscle hyperalgesia, which depends, at least in part, on increased expression of NaV1.7 in nociceptors.