Abstract
Objectives: Pain is a multifaceted phenomenon. Next to and in interaction with aberrations in central pain processes, behavioral factors and the neuroendocrine regulation system are also involved in pain. Our aim is to summarize neuroendocrine findings in fibromyalgia syndrome [FMS], to discuss how neuroendocrine functioning interacts with pain and psychological factors, and to confer implications of this inquiry for the management of FMS.
Findings: With respect to hypothalamic-pituitary-adrenal axis functioning, on average, normal cortisol levels, reduced corticotrophin responses to multiple stressors, and an exaggerated corticotrophin response to exogenous corticotrophin-releasing hormone [CRH] are found. This may reflect a hypoactive status of CRH neurons and, as a consequence, upregulation of pituitary CRH receptors. Studies of autonomic nervous system functioning show a hyporesponsiveness to a variety of stressors and indicate a persistent hyperactive sympathetic nervous system. Although a causal role of constitutional or acquired neuroendocrine dysregulation in FMS is not refuted, the reviewed findings suggest that neuroendocrine dysregulation is a consequence of current pain, psychological stress and distress, sleep disturbance, inactivity, and low fitness.
Conclusions: Essential aims in the tailored management of FMS are enhancement of functional capacity and quality of life, and symptomatic treatment of individual symptoms such as pain, distress, and sleep disturbances. Patient education, pharmacological interventions with analgesics and antidepressants, cognitive-behavioral therapy, sleep hygiene training, and low-intensity physical exercise training are commonly employed in tailored management of FMS. Our review suggests that favorable neuroendocrine changes are to be expected as part of a successful outcome of these therapeutic strategies.