Biomedical models of fibromyalgia.
OBJECTIVE
Fibromyalgia (FM) and chronic widespread pain (CWP) are common, but the etiology of these disorders remains poorly understood. A large body of data indicates a neurobiological basis for these disorders, but this information has not been effectively transmitted to many medical professionals.


METHODS
Contemporary data on the epidemiologic characteristics of FM and CWP are reviewed, and evidence for a neurobiological basis for these disorders is presented. In addition, possible predisposing, triggering, and maintaining factors for the development of these disorders are discussed.


RESULTS
Approximately 10% of the population have CWP, and approximately 4% have FM. The tender point criteria for FM have resulted in the common misconception among health care professionals that this spectrum of disorders is limited to women with high degrees of psychological distress. A hallmark of FM is the presence of non-nociceptive, central pain. There is evidence of centrally augmented pain processing, which can be detected both with sensory testing and by more objective measures (e.g., evoked potentials, functional neuroimaging).


CONCLUSIONS
An appreciation of the neurobiological basis for these disorders, and an understanding of some of the abnormalities of pain processing present in patients with FM, will hopefully provide greater understanding of these patients. It may also serve to decrease the level of frustration and improve the care experience of both chronic pain patients and physicians.
McLean
Samuel A
SA
University of Michigan Chronic Pain and Fatigue Research Center, 24 Frank Lloyd Wright Drive, Ann Arbor, MI 48106, USA. samclean@umich.edu
Clauw
Daniel J
DJ
D002908:Chronic Disease; D005260:Female; D005356:Fibromyalgia / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008959:Models, Neurological; D010146:Pain / Q000209:etiology*; D013315:Stress, Psychological / Q000150:complications*