Modulação da Dor na Síndrome Fibromiálgica: Um Distúrbio Termorregulatório?

Abstract

Several characteristics from Fibromyalgia Syndrome (FMS) suggest alterations in the thermoregulatory activity. There is an overl ap between thermoregulation and nociceptive modulation, consistent with the symptoms of the syndrome. Several studies, addressed in this review , describe common aspects between the regulation of pain and temperature, what may contribute to the generalized and persistent pain of FMS. Several findings, evidenced in the literature, support this idea: the distribution of Brown Fat (BAT) resembles the tender points; stress and cold cause sympathetic hyperactivity stimulating afferent fibers C, innervating BAT and adjacent tissues. They stimulate thermogenesis of BAT, which exacerbates hyperalgesia of FMS in regions corresponding to the tender points; physical activi ty acts in an antagonistic way, avoiding the BAT recruitment and alleviating the symptoms; women may be more susceptible to FMS, because they are less capable of initiating adaptive thermogenesis than men. The activation of the BAT has a peripheral vasoconstriction action, but it increase s the supraclavicular temperature. Infrared thermography may record the activation of BAT in the FMS through the mantle signal. Hands or feet immersion in water at 20oC test evaluates the aforementioned activation. Although not a definitive diagnosis, the phenomenon of the mantle and peripheral vasoconstriction may support the clinical diagnosis, having an important role in monitoring patients with FMS, as markers of autonomic dysfunction, present in this disease.