Fibromyalgia Syndrome: New Developments in Pathophysiology and Management

Fibromyalgia syndrome (FMS) is a common, chronically painful condition that is still seeking a home among the clinical professions. It is characterized by moderately severe soft-tissue pain and allodynia, which suggests a role for one group of specialists, but its pathogenesis is in the nociceptive machinery of the central nervous system, which defines the territory of other specialties. Comorbidities such as insomnia, cognitive dysfunction, depression, anxiety, recurrent headaches, dizziness, fatigue, morning stiffness, dysesthesia, irritable bowel syndrome, and irritable urethra logically invoke input from practitioners from almost every field of medicine.The precipitating causes of FMS may vary among individuals, but a mechanism underlying the painful symptoms involves central sensitization leading to an amplified perception of pain. As a result, this condition is recognized as the human model for chronic widespread allodynia. Biological abnormalities that are detected in most patients by objective methods include dysfunctional sleep (polysomnography), central sensitization (functional magnetic resonance imaging), temporal summation (windup, second pain), and facilitation of nociception (elevated spinal fluid levels of substance P, deficient biogenic amines that fail to maintain descending inhibition, and, in primary FMS, elevated spinal fluid levels of nerve growth factor).Treatment of FMS is symptomatic and multimodal, including education, physical modalities, and medications that target central neural pathways. Rehabilitation goals include improved physical function, social adaptation, emotional balance, and a better quality of life. Several series of placebo-controlled clinical trials have made available new medications with unique therapeutic mechanisms. Thus, it can be predicted that the next 10 years will see validation of a clinical case definition, more interest in the underlying pathogenesis, a better understanding of how medical care should be adapted to subgroup variations, new medications with specific domain indications, mechanism-directed polypharmacy, characterization of the genetic predisposition, and more emphasis on preventable inciting events.