Pain
-
Pain behaviors are important indicators of functioning in chronic pain; however, no self-reported pain behavior instrument has been developed for pediatric populations. The purpose of this study was to create a brief pediatric measure of patient-reported pain behaviors as part of the Patient-Reported Outcome Measurement Information System (PROMIS). A pool of 47 candidate items for this measure had been previously developed through qualitative research. ⋯ Results were used along with expert consensus and alignment with the adult PROMIS pain behavior items to arrive at an 8-item pediatric pain behavior short form, and all 47 items were retained in a calibrated item bank. Confirmatory factor analysis and correlations with validated measures of pain, pain interference, and psychosocial functioning provided support for the short form's reliability and validity. The new PROMIS pediatric pain behavior scale provides a reliable, precise, and valid measure for future research on pain behavior in school-aged children with chronic pain.
-
The aim of this study was to examine whether increases in severity of subclinical inflammation, measured by high-sensitivity C-reactive protein (hs-CRP), increased experimental pain sensitivity, measured by cold-pressor tolerance, and to test whether this relationship is independent of chronic pain. A large population-based study from 2007 to 2008, the sixth Tromsø Study, provided data from 12,981 participants. For the present analysis, complete data for 10,274 participants (age: median 58 years) were available. ⋯ Higher levels of hs-CRP were negatively related to cold-pressor tolerance (hazard ratio [HR] = 1.24, 95% confidence interval [CI], 1.12-1.37, P < 0.001), adjusted for age and sex. This relationship remained essentially unaltered after controlling for potential confounders (HR = 1.22, 95% CI, 1.09-1.36, P < 0.001), as well as for the presence of chronic pain (HR = 1.22, 95% CI, 1.09-1.36, P < 0.001). The present data show that subclinical inflammation is related to increased pain sensitivity, suggesting a potential role of inflammation in experimental pain which may be of importance for the development of clinical pain.
-
Obesity is associated with numerous chronic diseases, including musculoskeletal (MSK) pain, which affects on quality of life (QoL). There is, however, limited research providing a comprehensive MSK pain profile of an obese cohort. This retrospective study used a patient database at a national weight management service. ⋯ Patients who slept fewer hours and had poorer functional outcomes were more likely to have LBP; patients who were divorced, had lower QoL, and more frequent nocturia were more likely to have knee pain (P < 0.05). Multisite MSK pain is prevalent and severe in obese patients and is negatively associated with most self-report and functional outcomes. This high prevalence suggests that pain management strategies must be considered when treating obesity.
-
We previously developed a model of opioid-induced neuroplasticity in the peripheral terminal of the nociceptor that could contribute to opioid-induced hyperalgesia, type II hyperalgesic priming. Repeated administration of mu-opioid receptor (MOR) agonists, such as DAMGO, at the peripheral terminal of the nociceptor, induces long-lasting plasticity expressed, prototypically as opioid-induced hyperalgesia and prolongation of prostaglandin E2-induced hyperalgesia. In this study, we evaluated the mechanisms involved in the maintenance of type II priming. ⋯ A second model of priming, latent sensitization, induced by complete Freund's adjuvant was also reversed, in males. In females, the inhibitor combination was only able to inhibit the expression and maintenance of DAMGO-induced priming when knockdown of G-protein-coupled estrogen receptor 30 (GPR30) in the nociceptor was performed. These findings demonstrate that the maintenance of DAMGO-induced type II priming, and latent sensitization is mediated by an interaction between, Src and MAP kinases, which in females is GPR30 dependent.
-
Thoracotomy results in chronic postoperative pain (CPTP) in half of the cases. Earlier findings in rat models of persistent post-surgical pain suggest that spinal pathways are critical for pain onset but not its maintenance. Descending systems from the brain stem modulate nociceptive transmission in the spinal cord and contribute to persistent pain, but their role in chronic postoperative pain has not been studied. ⋯ SSP-SAP given at postoperative day 10 was equally effective in ablating NK-1R neurons but fully reversed mechano-hypersensitivity in only 3 of 9 hypersensitive rats. Fewer rats showed intense pain-like behavior, by Qualitative Hyperalgesia Profile analysis, in the Prevention than in the Control conditions, and the more intense pain behaviors declined along with SSP-SAP-induced Reversal of hypersensitivity. Neurokinin-1 receptor-expressing neurons in RVM appear essential for the development but contribute only partially to the maintenance of CPTP.