Pain
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Randomized Controlled Trial
Comparing the DN4 tool with the IASP Grading System for Chronic Neuropathic Pain Screening After Breast Tumor Resection With and Without Paravertebral Blocks: A Prospective Six-month Validation Study.
Investigating protective strategies against chronic neuropathic pain (CNP) after breast cancer surgery entails using valid screening tools. The DN4 (Douleur Neuropathique en 4 questions) is 1 tool that offers important research advantages. This prospective 6-month follow-up study seeks to validate the DN4 and assess its responsiveness in screening for CNP that satisfies the International Association for the Study of Pain (IASP) definition and fulfills its grading system criteria after breast tumor resection with and without paravertebral blocks (PVBs). ⋯ Therefore, the sensitivity and specificity of the DN4 were estimated at 90% and 60%, respectively. Both screening tools suggested that PVB reduced the 6-month CNP risk. Our results suggest that the DN4 can reliably identify CNP at 6 months after breast tumor resection and detect the preincisional PVB effect on the risk of developing such pain.
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Randomized Controlled Trial
Targeted alterations in dietary n-3 and n-6 fatty acids improve life functioning and reduce psychological distress among patients with chronic headache: a secondary analysis of a randomized trial.
Omega-3 and omega-6 fatty acids are precursors of bioactive lipid mediators posited to modulate both physical pain and psychological distress. In a randomized trial of 67 subjects with severe headaches, we recently demonstrated that targeted dietary manipulation-increasing omega-3 fatty acids with concurrent reduction in omega-6 linoleic acid (the H3-L6 intervention)-produced major reductions in headache compared with an omega-6 lowering (L6) intervention. Because chronic pain is often accompanied by psychological distress and impaired health-related quality of life (HRQOL), we used data from this trial to examine whether the H3-L6 intervention favorably impacted these domains. ⋯ In the intention-to-treat analysis, participants in the H3-L6 group experienced statistically significant reductions in psychological distress (BSI-18 mean difference: -6.56; 95% confidence interval [CI]: -11.43 to -1.69) and improvements in SF-12 mental (mean difference: 6.01; 95% CI: 0.57 to 11.45) and physical (mean difference: 6.65; 95% CI: 2.14 to 11.16) health summary scores. At 12 weeks, the proportion of subjects experiencing substantial impairment according to cutoff values in the BSI-18, SF-12 physical, HIT-6, and headache days per month was significantly lower in the H3-L6 group. Dietary manipulation of n-3 and n-6 fatty acids, previously shown to produce major improvements in headache, was found to also reduce psychological distress and improve HRQOL and function.
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Randomized Controlled Trial
GABAAergic inhibition or dopamine denervation of the A11 hypothalamic nucleus induces trigeminal analgesia.
Descending pain-modulatory systems, either inhibitory or facilitatory, play a critical role in both acute and chronic pain. Compared with serotonin and norepinephrine, little is known about the function of dopamine (DA). We characterized the anatomical organization of descending DA pathways from hypothalamic A11 nuclei to the medullary dorsal horn (MDH) and investigated their role in trigeminal pain. ⋯ Interestingly, however, pain seems to activate GABAergic neurons within A11 nuclei, which suggests that pain inhibits rather than activates descending DA controls. We show that such inhibition produces an antinociceptive effect. Pain-induced inhibition of descending DA controls and the resulting reduced DA concentration within the dorsal horn may inhibit the transfer of nociceptive information to higher brain centers through preferential activation of dorsal horn D2-like receptors.
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Randomized Controlled Trial
Trajectories of Change During a Randomized Controlled Trial of Internet-delivered Psychological Treatment for Adolescent Chronic Pain: How does Change in Pain and Function Relate?
Although pain and function improve at immediate posttreatment for youth receiving cognitive behavioral therapy for chronic pain, limited data are available to understand changes that youth make during psychological treatment. We sought to characterize distinct trajectory patterns of change in pain and function to understand the temporal association of these changes during internet-delivered cognitive behavioral therapy (CBT). Weekly repeated assessments of pain and function were conducted during 8 weeks of treatment among 135 adolescents, aged 11 to 17 years, with chronic pain who were randomized to the cognitive behavioral intervention arm of an ongoing trial of internet-delivered CBT (Web-based management of adolescent pain; Web-MAP2). ⋯ There was no support for improvements in either pain or function to precede changes in the other domain. Findings may be useful in informing future studies of psychosocial treatments for pediatric chronic pain to consider how to target treatment strategies to distinct patient response profiles. This may lead to the development of intervention strategies that can both more effectively target children's pain and function during treatment and lead to sustained changes after treatment.