95 research outputs found
Central motor control failure in fibromyalgia: a surface electromyography study
No full textAbstract Background Fibromyalgia (FM) is characterised by diffuse musculoskeletal pain and stiffness at multiple sites, tender points in characteristic locations, and the frequent presence of symptoms such as fatigue. The aim of this study was to assess whether the myoelectrical manifestations of fatigue in patients affected by FM are central or peripheral in origin. Methods Eight female patients aged 55.6 ± 13.6 years (FM group) and eight healthy female volunteers aged 50.3 ± 9.3 years (MCG) were studied by means of non-invasive surface electromyography (s-EMG) involving a linear array of 16 electrodes placed on the skin overlying the biceps brachii muscle, with muscle fatigue being evoked by means of voluntary and involuntary (electrically elicited) contractions. Maximal voluntary contractions (MVCs), motor unit action potential conduction velocity distributions (mean ± SD and skewness), and the mean power frequency of the spectrum (MNF) were estimated in order to assess whether there were any significant differences between the two groups and contraction types. Results The motor pattern of recruitment during voluntary contractions was altered in the FM patients, who also showed fewer myoelectrical manifestations of fatigue (normalised conduction velocity rate of changes: -0.074 ± 0.052%/s in FM vs -0.196 ± 0.133%/s in MCG; normalised MNF rate of changes: -0.29 ± 0.16%/s in FM vs -0.66 ± 0.34%/s in MCG). Mean conduction velocity distribution and skewnesses values were higher (p Conclusion The apparent paradox of fewer myoelectrical manifestations of fatigue in FM is the electrophysiological expression of muscle remodelling in terms of the prevalence of slow conducting fatigue-resistant type I fibres. As the only between-group differences concerned voluntary contractions, they are probably more related to central motor control failure than muscle membrane alterations, which suggests pathological muscle fibre remodelling related to altered suprasegmental control.</p
Diagnosis of fibromyalgia: comparison of the 2011/2016 ACR and AAPT criteria and validation of the modified Fibromyalgia Assessment Status
No full textOBJECTIVE: To compare the concordance of the three diagnostic criteria, respectively the 2011 ACR criteria (ACR 2011 Cr), the ACR 2016 criteria (ACR 2016 Cr) and the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION)-APS Pain Taxonomy criteria (AAPT Cr), and to explore the performance of an additional set of criteria, the modified Fibromyalgia Assessment Status (FAS 2019 modCr), in the diagnosis of FM syndrome.
METHODS: Consecutive patients with chronic widespread pain, referred by the primary care setting, underwent rheumatologic assessment that established the presence or not of FM and were investigated through the four sets of proposed criteria. For the FAS 2019 modCr, discriminant validity to distinguish patients with FM and non-FM was assessed with receiver operating characteristic curve analysis.
RESULTS: A total of 732 (405 with FM and 327 with other common chronic pain problems) patients were evaluated. Against the clinical diagnosis of FM, the sensitivity, specificity and correct classification were, respectively: 79.8, 91.7 and 85.1% for ACR 2011 Cr; 78, 90.5 and 83.6% for the ACR 2016 Cr; and 73.8, 91.7 and 81.8% for the AAPT Cr. The alternative set, proposed on the FAS 2019 modCr, provided a maximal diagnostic accuracy with a score ≥20 (Youden's index), with a sensitivity of 84.2%, specificity 89.0% and positive likelihood ratio 7.65.
CONCLUSION: There is a considerable agreement between criteria-based diagnoses of FM, although the AAPT Cr perform least well in terms of percentage of correct classification. The FAS 2019 modCr had comparable characteristics
Comment on: Diagnosis of fibromyalgia: comparison of the 2011/2016 ACR and AAPT criteria and validation of the modified Fibromyalgia Assessment Status. Reply
No full text
- …
