Evidence for metabolic abnormalities in the muscles of patients with fibromyalgia

Abstract

Widespread muscle pain, fatigue, and weakness are defining characteristics of patients with fibromyalgia (FM). The aim of this review is to summarize recent investigations of muscle abnormalities in FM, which can be classified as structural, metabolic, or functional in nature. Histologic muscle abnormalities of membranes, mitochondria, and fiber type have been well described at both the light microscopic and ultrastructural levels. These structural abnormalities often correlate with biochemical abnormalities, defective energy production, and the resultant dysfunction of FM muscles. The observed abnormalities in FM muscles are consistent with neurologic findings and disturbances in the hypothalamic-pituitary-adrenal axis. Functional changes in FM muscles are assessed most directly by strength and endurance measurements, but pain and psychologic factors may interfere with accurate assessments. To compensate for diminished effort, the decreased efficiency of the work performance by patients with FM can be verified from P-31 magnetic resonance spectroscopy (MRS) data by calculation of the work/energy-cost ratio for various tasks. In the disease course, muscle abnormalities may be elicited by intrinsic changes within the muscle tissue itself and/or extrinsic neurologic and endocrine factors. The accurate assignment of intrinsic or extrinsic factors has been substantially clarified by a recent surge of experimental findings. Irrespective of the multifaceted causes of muscle dysfunction and pain, an in-depth understanding of the muscle defects may provide ideas for characterization of the underlying pathogenesis and development of new therapeutic approaches for fibromyalgia syndrome.

EEG Biofeedback Treatment Improves Certain Attention and Somatic Symptoms in Fibromyalgia: A Pilot Study

“…Nevertheless, our findings should not be taken as evidence for an isolated CNS pathogenesis in FMS since unequivocal peripheral abnormalities have been identified in this syndrome. These abnormalities include those of muscle tissue (Olsen and Park 1998;Park et al 2000;Sprott et al 2004), the PNS, and the autonomic nervous system (Raj et al 2000;Cohen et al 2001;Ulas et al 2006;Caro et al 2008), and the immune system (Caro 1989;Salemi et al 2003;Caro and Winter 2005;Caro and Winter 2008;Caro et al 2008). Nevertheless, it is known that CNS pain perception may interact somewhat with attention related cognition (Pickering et al 2002).…”

Fibromyalgia: A Critical and Comprehensive Review

“…This is further supported by reduced levels of muscular ATP and phosphocreatine, even if they are not consistently observed and even if it is not clear to what extent the physical inactivity and deconditioning of FMS patients contribute to these findings [488,[494][495][496]. Further evidence of mitochondrial dysfunction comes from PBMC and skin of FMS patients [435,497,498].…”

“…The results have been inconsistent, but to date no morphological abnormality specific to FMS has been identified, and no signs of inflammation have been detected. Nonetheless, various non-specific alterations have been described with increased frequency in muscle biopsy samples from FMS patients compared to healthy controls [488,489]. These include an increased occurrence of motheaten fibers and ragged red fibers, which reflects the abnormalities in the number, shape, and distribution of mitochondria that becomes obvious during electron microscopy [489][490][491].…”

“…Reduced capillary density and capillary thickening could be either the cause or the result of localized hypoxia, but either way, these results suggest that tissue hypoperfusion could play an important role in the development or maintenance of pain and other symptoms in FMS. There are indications that muscle blood flow is diminished in patients with FMS compared to healthy controls particularly during and after muscle activity, even if the results are not entirely consistent [385,488,492]. A major determinant of these discrepancies may be the differential responses of FMS and control subjects to needle insertion trauma, prolonged inactivity or both [492].…”

Review of the mechanisms involved in a complex pain syndrome: fibromyalgia

“…Si la performance musculaire est déficiente chez les fibromyalgiques, il est possible que des perturbations métaboliques en soient aussi responsables [137,184]. Il a été démontré, par exemple, que le métabolisme glucidique (glycolyse) est moins efficace au niveau des fibres musculaires de fibromyalgiques [43], que le métabolisme oxydatif est également perturbé [95] et que les réserves intracellulaires de calcium et de magnésium au sein des fibres musculaires sont inférieures à celles retrouvées chez des individus en bonne santé [103].…”