Pain Physiology Education Improves Health Status and Endogenous Pain Inhibition in Fibromyalgia A Double-Blind Randomized Controlled Trial Jessica Van Oosterwijck, PT, PhD,*wz Mira Meeus, PT, PhD,*w Lorna Paul, PT, PhD,y Mieke De Schryver, PT, MSc,* Aurelie Pascal, PT, MSc,* Luc Lambrecht, MD, PhD,8 and Jo Nijs, PT, PhD*wz Objectives: There is evidence that education on pain physiology can have positive effects on pain, disability, and catastrophization in patients with chronic musculoskeletal pain disorders. A double- blind randomized controlled trial (RCT) was performed to examine whether intensive pain physiology education is also effective in fibromyalgia (FM) patients, and whether it is able to influence the impaired endogenous pain inhibition of these patients. Methods: Thirty FM patients were randomly allocated to either the experimental (receiving pain physiology education) or the control group (receiving pacing self-management education). The primary outcome was the efficacy of the pain inhibitory mechanisms, which was evaluated by spatially accumulating thermal nociceptive stimuli. Secondary outcome measures included pressure pain threshold measurements and questionnaires assessing pain cogni- tions, behavior, and health status. Assessments were performed at baseline, 2 weeks, and 3 months follow-up. Repeated measures ANOVAS were used to reveal possible therapy effects and effect sizes were calculated. Results: After the intervention the experimental group had improved knowledge of pain neurophysiology (P < 0.001). Patients from this group worried less about their pain in the short term (P = 0.004). Long-term improvements in physical functioning (P = 0.046), vitality (P = 0.047), mental health (P < 0.001), and general health perceptions (P <0.001) were observed. In addition, the intervention group reported lower pain scores and showed improved endogenous pain inhibition (P = 0.041) compared with the control group. Discussion: These results suggest that FM patients are able to understand and remember the complex material about pain physiology. Pain physiology education seems to be a useful com- ponent in the treatment of FM patients as it improves health status and endogenous pain inhibition in the long term. Key Words: patient education, conditioned pain modulation, spa- tial summation, rehabilitation, central sensitization. (Clin J Pain 2013;29:873–882) F ibromyalgia (FM) is characterized by the presence of chronic widespread pain 1,2 and studies have demon- strated exaggerated pain responses after sensory stim- ulation of healthy tissues. 3 This has led to the hypothesis that the central nervous system is hyperexcitable in these patients and that pain could be perceived in the absence of a nociceptive input, due to induction of irreversible plasticity changes in the central nervous system (CNS). 4 Staud et al 5,6 found evidence for this hypothesis in FM patients and demonstrated that hypersensitivity of the CNS or central sensitization is a characteristic of FM. Sensitivity to pain results from the outcome of the balance between pain facilatory and inhibitory pathways, which either potentiate (descending facilitation) or suppress (descending inhibition) the passage of nociceptive messages to the brain. 7 Malfunctioning of these central inhibitory pathways seems to be responsible for abnormal spatial summation and contributes to central sensitization in people with chronic pain. 8–10 In FM patients a disturbed and/or impaired descending nociceptive inhibition has been ob- served. 10 It has been shown that pain inhibitory systems are not optimally recruited by spatial summation procedures (SSP) using noxious conditioning stimuli in FM patients, in contrast to chronic low back pain patients and pain-free individuals. 10,11 Although some researchers have observed normal spatial summation responses, 12 efficient activation of the pain modulatory systems in FM 12–14 has only been established when short and/or innocuous stimuli are utilized. The dysfunctional descending nociceptive inhibitory mechanism as seen in FM is primarily biological, but is influenced by negative and maladaptive thoughts, emotions, cognitions, and behaviors like catastrophizing, hypervigilance, avoidance behavior, and somatization. 3 These negative cog- nitions can develop when FM patients do not understand the origin of their generalized musculoskeletal chronic pain and can facilitate pain. Therefore they need to be addressed during therapy, for instance, through education. 15,16 Most of the educational models have limited efficacy in decreasing pain and disability in patients with chronic musculoskeletal pain, and may even increase patients’ fears Received for publication May 25, 2012; revised October 28, 2012; accepted November 4, 2012. From the *Department of Human Physiology, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel; zDepartment of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels; wDepartment of Health Care Sciences, Division of Musculoskeletal Physiotherapy, Artesis University College Antwerp, Antwerp; 8Private Practice for Internal Medicine, Gent/Aalst, Belgium; and yNursing and Health Care, School of Medicine, University of Glasgow, Glasgow, UK. J.V.O. is financially supported by grant no. OZR1596 from the research council of the Vrije Universiteit Brussel, Brussels, Belgium. M.M. is a postdoctoral research fellow of the Research Foundation Flan- ders (FWO). The remaining authors declare no conflict of interest. Reprints: Jo Nijs, PT, PhD, Department of Human Physiology, Fac- ulty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Building L-3rd floor, Pleinlaan 2, Brussels BE-1050, Belgium (e-mail: jo.nijs@vub.ac.be). Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Website, www.clinicalpain.com. Copyright r 2013 by Lippincott Williams & Wilkins ORIGINAL ARTICLE Clin J Pain  Volume 29, Number 10, October 2013 www.clinicalpain.com | 873