Fibromyalgia (FM) is currently classified as chronic widespread pain with widespread allodynia/hyperalgesia to pressure pain and is categorized among the large group of soft-tissue pain syndromes. FM remains an elusive condition of unknown etiology in which patients report not only chronic widespread pain but also a variety of other complaints, so that it is one of several relatively common overlapping syndromes characterized by otherwise unexplained chronic pain and fatigue (1, 2)...