ABSTRACT
INTRODUCTION: Fibromyalgia (FM) is a common chronic pain disorder characterized by whole-body pain and multiple symptoms. This study investigated potential dysfunctions of the Autonomic Nervous System (ANS) in FM patients through the measurement of the autonomic response during a cold-water test. METHODS: 23 female patients with FM and 15 healthy female controls were recruited. First, FM patients filled out the following questionnaires: PainDETECT, American College of Rheumatology (ACR) criteria of FM, and Profile of Mood States (POMS). Healthy controls only filled out the POMS. Subsequently, all participants immersed their forearm into 1 degrees C cold-water as long as they could tolerate for a maximum of 120 seconds. A thermographic camera recorded skin temperature and its recuperation process. RESULTS: The two groups differed significantly regarding central body temperature, forearm thermography, and peripheral (forearm)-central (ear) temperature ratio. FM patients showed less tolerance to cold water than control participants. Although total temperature decrease, cool-down rate, recuperation between 0 and 20 minutes after withdrawal showed significant intergroup differences, thermal recovery followed similar patterns in both groups. DISCUSSION: Peculiar ANS baseline characteristics are seen in FM patients. Although those patients have reduced ability to sustain low temperatures, therefore limiting extrapolation of inter-group analysis, their thermal-adaptive responses were found different as compared to controls.
