Pain
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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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Chronic stressful events induce biochemical, physiological and psychological changes, resulting in stress-related neuropsychiatric disorders, such as anxiety or depression. Using repeated social defeat as a stressful event model, we show that this preclinical paradigm induces a transient increase in the expression of the genes encoding the pro-inflammatory molecules iNOS and COX-2. We provide the first demonstration that chronic stress affects spinal plasticity through a mechanism involving local neuroinflammation. ⋯ The present study highlights the adverse effects of chronic stress on spinal neuroinflammation triggering sensory hypersensitivity. Exploration of this phenomenon points out the divergence between pain sensitivity and anxiety-induced hyperalgesia, which is in agreement with clinical observations. Altogether, these data open up new perspectives for clinical research devoted to the evaluation and treatment of pain in anxio-depressive patients.
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Review
Gender differences in pain modulation by diffuse noxious inhibitory controls: a systematic review.
Over the last decade, extensive research has demonstrated sex differences in pain perception and modulation. Several factors have been proposed to account for the differences observed between men and women, including pain modulation through diffuse noxious inhibitory controls (DNIC). Studies investigating sex differences in DNIC have shown mixed results, with some reporting decreased DNIC effect in women compared with men, while others found no difference in DNIC between the sexes. ⋯ The majority of studies using pain report as the outcome found significantly more efficient DNIC in males than females (mean female/male ratio=0.54). Studies evaluating pain thresholds and nociceptive flexion reflex indicated the opposite when simply averaged across studies; however, weighted analyses of threshold found more efficient DNIC in males. Gender differences in DNIC effect depend on both the experimental methodology and the modes of measurement of the effect.
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Current IASP diagnostic criteria for CRPS have low specificity, potentially leading to overdiagnosis. This validation study compared current IASP diagnostic criteria for CRPS to proposed new diagnostic criteria (the "Budapest Criteria") regarding diagnostic accuracy. Structured evaluations of CRPS-related signs and symptoms were conducted in 113 CRPS-I and 47 non-CRPS neuropathic pain patients. ⋯ As designed, the Budapest research criteria resulted in the highest specificity (0.79), again replicating prior work. Analyses indicated that inclusion of four distinct CRPS components in the Budapest Criteria contributed to enhanced specificity. Overall, results corroborate the validity of the Budapest Criteria and suggest they improve upon existing IASP diagnostic criteria for CRPS.