Fibromyalgia, chronic fatigue syndrome, and myofascial pain syndrome.

There continues to be an emerging body of literature related to fibromyalgia and the related conditions chronic fatigue syndrome and myofascial pain. During the past year, the most notable contributions included a large multicenter study providing new diagnostic criteria for the classification of fibromyalgia and clinical studies describing the overlap of fibromyalgia, chronic fatigue syndrome, and myofascial pain. Pathophysiologic studies were often preliminary and uncontrolled but the focus of these studies on abnormal nociception, neurohormones, and muscle metabolism provides an exciting hypothesis to unify pain, fatigue, and sleep disturbances, the primary symptoms of fibromyalgia. Unfortunately, new therapeutic trials were neither innovative nor especially encouraging.