Pain
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Due to maturation-related plasticity of the developing nociceptive system, neonatal nociceptive input, as induced by medical procedures in the neonatal intensive care unit (NICU), may cause long-term alterations in pain processing. Using functional magnetic resonance imaging, this study investigated the cerebral pain response in school-aged children and adolescents (11-16 yr) with experience in a NICU after preterm (
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Somatosensory neurons detect environmental stimuli, converting external cues into neural activity that is relayed first to second-order neurons in the spinal cord. The detection of cold is proposed to be mediated by the ion channels TRPM8 and TRPA1. However, there is significant debate regarding the role of each channel in cold-evoked pain, complicating their potential as drug targets for conditions such as cold allodynia and hyperalgesia. ⋯ Furthermore, nocifensive behaviors to the cold-mimetic icilin are absent in TRPM8(-/-) and DKO mice, but are retained in TRPA1-nulls (TRPA1(-/-)). Finally, neural activity, measured by expression of the immediate-early gene c-fos, evoked by hindpaw stimulation with noxious cold, menthol, or icilin is reduced in TRPM8(-/-) and DKO mice, but not in TRPA1(-/-) animals. Thus our results show that noxious cold signaling is exclusive to TRPM8, mediating neural and behavioral responses to cold and cold-mimetics, and that TRPA1 is not required for acute cold pain in mammals.
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This is a prospective pilot study looking at the utility of Transcutaneous Electrical Nerve Stimulator (TENS) trial as a screening tool prior to spinal cord stimulator (SCS) implant to identify patients who may fail a SCS trial. The accepted screening test prior to a permanent SCS implant is a SCS trial. Patients may fail the SCS trial due to several causes of which one is the inability to tolerate stimulation induced paresthesias. ⋯ We noted a significant correlation between ability to tolerate TENS and SCS induced paresthesias. Statistically significant correlation was also noted between pre SCS trial anxiety score and high pain score during SCS trial. We conclude that there is potential applicability of a TENS trial as a non invasive screening tool which may promote cost effectiveness and decrease unnecessary procedural risks to the patient by avoiding SCS trial in select patients.
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The goal of this study was to develop and validate a self-completed questionnaire, the Fibromyalgia Rapid Screening Tool (FiRST), for the detection of fibromyalgia syndrome in patients with diffuse chronic pain. Items requiring "yes/no" responses and relating to the most relevant clinical characteristics of fibromyalgia were compiled by a group of rheumatologists and pain experts. The provisional questionnaire was tested in a prospective multicenter study of 162 patients with chronic pain due to fibromyalgia (according to ACR criteria) (n=92) compared with a group of patients with chronic diffuse pain due to other rheumatic conditions, including rheumatoid arthritis (n=32), ankylosing spondylitis (n=25) and osteoarthritis (n=13). ⋯ These items were used to calculate the sensitivity, specificity and predictive accuracy of the questionnaire. A cut-off score of 5 (corresponding to the number of positive items) gave the highest rate of correct identification of patients (87.9%), with a sensitivity of 90.5% and a specificity of 85.7%. In conclusion, FiRST is a brief, simple and straightforward self-administered questionnaire with excellent discriminative value, of potential value for the detection of fibromyalgia in both daily practice and clinical research.
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The use of chronic opioid therapy (COT) for chronic non-cancer pain (CNCP) has increased dramatically in the past two decades. There has also been a marked increase in the abuse of prescribed opioids and in accidental opioid overdose. Misuse of prescribed opioids may link these trends, but has thus far only been studied in small clinical samples. ⋯ Among non-modifiable factors, younger age, back pain, multiple pain complaints and substance abuse disorders identify patients at high risk for misuse. Among modifiable factors, treatment with high daily dose opioids (especially >120 mg MED per day) and short-acting Schedule II opioids appears to increase the risk of misuse. The consistency of the findings across diverse patient populations and the varying levels of misuse suggest that these results will generalize broadly, but await confirmation in other studies.