Fibromyalgia (FMS) is a chronic syndrome characterized by generalized pain, joint rigidity, and intense fatigue. Other frequently associated symptoms are sleep alterations, headache, spastic colon, craniomandibular dysfunction, anxiety, and depression. Fibromyalgia has a negative effect on the quality of life of patients, who often feel incapable of performing such basic daily life activities as walking, going up stairs, or lifting objects, increasing their disability index and utilization of health services [1
The etiology of the disease is currently unknown but several hypotheses have been developed, given that fibromyalgia syndrome is a multidisciplinary problem approached from different perspectives. Histological and histochemical studies have demonstrated that it is not an inflammatory process [3
]. The most widely accepted hypothesis is that chronic pain in FMS is of muscle origin, although plasma muscle enzyme levels, electromyographic studies, and muscle biopsies have proven completely normal [4
]. The methodological approach to muscle studies has been varied, from muscle biopsies for structural study to electromyograms and muscle metabolism studies using spectroscopic nuclear magnetic resonance (NMR). Results have shown characteristics associated with pain perception changes, sleep alterations, decrease in brain serotonin levels, and abnormalities in microcirculation and muscle energy metabolism [7
]. Taken together, these alterations contribute to neuronal hyperreactivity and myofascial distress, indicating that the origin of the pain may be related to myofascial trigger points or musculoskeletal changes.
Modifications of adrenocorticotropic hormone levels and a decrease in plasma serotonin have been reported in some of these patients, indicating central nervous system (CNS) involvement and neurohormonal axis changes. In this regard, there is evidence of interaction between low sleep quality and low plasma levels of serotonin, a neurotransmitter that functions in the neuromodulation of sleep, pain, and mood [8
]. Various studies have demonstrated that the perception of pain in FMS is related to CNS modifications that translate into the amplification of nociceptive impulses [11
]. This phenomenon is designated “central sensitization” and is believed to result from the plasticity of neuronal synapses in response to previous painful experiences. Different degrees of central sensitization have been described, explaining the variations in pain reported by FMS patients. Although there is no specific peripheral tissue anatomy that characterizes fibromyalgia, this does not reduce the importance of peripheral nociceptive mechanisms [12
]. CNS sensitization leads peripheral pain generators to trigger major nociceptive impulses that will in turn increase central sensitization. The most frequent peripheral pain generators in FMS include: myofascial trigger points, degenerative joint disease, inflammatory joint disease, bursitis, tendinitis, development alterations, hypermobility syndrome, neuropathic pain, injuries, traumas, repeated muscle pulls, visceral pain, disk herniation, spinal stenosis, and recurrent cephalalgia [14
There is no evidence of muscle disease in FMS but there are reports of dysfunction in intramuscular connective tissue or fascia; fascial inflammation triggers a peripheral nociceptive stimulus that leads to central sensitization in FMS [16
]. Immunohistochemical studies of fascial tissue biopsies reveal an increase in collagen levels and inflammation mediators in connective tissue surrounding muscle cells [16
]. In line with these findings, an exploratory and tentative study suggested the presence of latent and active myofascial trigger points in patients with FMS and myofascial pain syndrome [17
1.1. Purpose of the Study
Because the cause of FMS syndrome remains unknown, treatment is usually in response to symptoms. However, the effectiveness of pharmacological and nonpharmacological treatments has been limited. The purpose of this study was to determine the benefits of massage-myofascial release therapy on pain, anxiety, quality of sleep, depression, and quality of life in patients with FMS.