Muscle fiber velocity and electromyographic signs of fatigue in fibromyalgia
Department of Neurology and Clinical Neurophysiology, Ziekenhuis Groep Twente, Morshoekweg 3, 7552 PE Hengelo, The Netherlands. . Muscle & Nerve
(Impact Factor: 2.28).
11/2012; 46(5):738-45. DOI: 10.1002/mus.23382
Fibromyalgia (FM) is a disorder of widespread muscular pain. We investigated possible differences in surface electromyography (sEMG) in clinically unaffected muscle between patients with FM and controls.
sEMG was performed on the biceps brachii muscle of 13 women with FM and 14 matched healthy controls during prolonged dynamic exercises, unloaded, and loaded up to 20% of maximum voluntary contraction. The sEMG parameters were: muscle fiber conduction velocity (CV); skewness of motor unit potential (peak) velocities; peak frequency (PF) (number of peaks per second); and average rectified voltage (ARV).
There was significantly higher CV in the FM group. Although the FM group performed the tests equally well, their electromyographic fatigue was significantly less expressed compared with controls (in CV, PF, and ARV).
In the patients with FM, we clearly showed functional abnormalities of the muscle membrane, which led to high conduction velocity and resistance to fatigue in electromyography.
Available from: Celia Barbosa
[Show abstract] [Hide abstract]
ABSTRACT: BACKGROUND: Temporomandibular disorder (TMD) development in fibromyalgia syndrome (FMS) is not yet fully understood but altered neuromuscular control in FMS may play a role in triggering TMD. OBJECTIVE: The purpose of this study was to verify the association between neuromuscular control and chronic facial pain in groups of patients with FMS and TMD. DESIGN: A cross-sectional study was conducted. METHODS: This study involved an analysis of facial pain, electromyographic amplitude and frequency of masticatory muscles in patients with FMS (n=27) and TMD (n=28). All subjects were evaluated according to RDC/TMD and surface electromyography (SEMG). Myoelectric signal calculations were performed using the Root Mean Square (RMS) and Median Frequency (MNF) of signals. RESULTS: Our data reveals premature interruption of masticatory muscle contraction in both patient groups but a significant correlation was also found between higher MNF values and increased facial pain. This is probably related to FMS since this correlation was not found in patients with TMD only. Facial pain and increased SEMG activity during mandibular rest were also positively correlated. LIMITATIONS: Temporal conclusions cannot be drawn from our study. Also, the study lacked a comparison group of patients with FMS without TMD as well as a healthy control group. CONCLUSIONS: Altered neuromuscular control in masticatory muscles may be correlated with perceived facial pain in patients with FMS.
[Show abstract] [Hide abstract]
ABSTRACT: Fibromyalgia is a disorder that is part of a spectrum of syndromes that lack precise classification. It is often considered as part of the global overview of functional somatic syndromes that are otherwise medically unexplained or part of a somatization disorder. Patients with fibromyalgia share symptoms with other functional somatic problems, including issues of myalgias, arthralgias, fatigue and sleep disturbances. Indeed, there is often diagnostic and classification overlap for the case definitions of a variety of somatization disorders. Fibromyalgia, however, is a critically important syndrome for physicians and scientists to be aware of. Patients should be taken very seriously and provided optimal care. Although inflammatory, infectious, and autoimmune disorders have all been ascribed to be etiological events in the development of fibromyalgia, there is very little data to support such a thesis. Many of these disorders are associated with depression and anxiety and may even be part of what has been sometimes called affected spectrum disorders. There is no evidence that physical trauma, i.e., automobile accidents, is associated with the development or exacerbation of fibromyalgia. Treatment should be placed on education, patient support, physical therapy, nutrition, and exercise, including the use of drugs that are approved for the treatment of fibromyalgia. Treatment should not include opiates and patients should not become poly pharmacies in which the treatment itself can lead to significant morbidities. Patients with fibromyalgia are living and not dying of this disorder and positive outlooks and family support are key elements in the management of patients.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.