Brain-derived neurotrophic factor and exercise in fibromyalgia syndrome patients: a mini review.

Fibromyalgia syndrome (FMS) is a common chronic pain condition characterized by chronic widespread pain and decreased pain threshold, with hyperalgesia and allodynia. Associated signs include fatigue, morning stiffness, non-restorative sleep, mood disturbance, depression, irritable bowel syndrome, and headache. In addition to the administration of drugs, psychological therapies treatment of FMS mainly consists of physical therapies. Although the precise pathogenesis of FMS remains elucidated, modern understanding conceptualizes FMS as central sensitization as a consequence of altered endogenous pain- and stress-response system and continuous nociceptive input. Altered brain-derived neurotrophic factor (BDNF) levels in FMS suggest that BDNF--well known for its effects on neuronal plasticity--is involved in this sensitization process. Exercise leads to changes in serum BDNF levels, too. This association highlights the importance of exercise in FMS and other chronic pain conditions.