 While there is debate as to specific etiology and pathogenesis, fibromyalgia is generally believed to be the result of a perturbation of central pain processing, specifically the neuroendocrine system. Fibromyalgia patients have been shown to have lower levels of metabolites from three neurotransmitters serotonin, norepinephrine, and dopamine in their cerebrospinal fluid CSF compared to healthy controls. The low rate of turnover of these neurotransmitters supports the hypothesis of a metabolic defect in fibromyalgia and suggests that the defect occurs at a neuroregulatory level. Results of a study that examined the effect of a permanent reduction in the noradrenergic innervation of the spinal cord suggested that the antinociceptive effects of norepinephrine are closely linked to opioidergic and tachykinergic neurotransmission. 