Fibromyalgia syndrome (FMS) is a chronic widespread pain condition with characteristic tender points (TP) on physical examination, often associated with a constellation of other symptoms such as fatigue, sleep disturbance, stiffness and mood disorders (Wolfe et al., 1990). The etiology of FMS is not completely understood, but the syndrome is thought to arise from a number of possible influencing factors, including genetic disposition and dysfunction of the central and autonomous nervous system (resulting in amplification of pain transmission and interpretation), although various other mechanisms could be involved.