Do cognitive and physical fatigue tasks enhance pain, cognitive fatigue, and physical fatigue in people with fibromyalgia?

OBJECTIVE: Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue. The primary objective of this study was to determine if pain, perceived cognitive fatigue, and perceived physical fatigue were enhanced in participants with fibromyalgia compared to healthy controls during a cognitive fatigue task, a physical fatigue task, and a dual fatigue task. METHODS: In total, 24 people with fibromyalgia and 33 healthy controls completed pain, fatigue, and function measures. A cognitive fatigue task (Controlled Oral Word Association Test) and physical fatigue task (Valpar peg test) were done individually and combined for a dual fatigue task. Resting pain, perceived cognitive fatigue, and perceived physical fatigue were assessed during each task using visual analog scales. Function was assessed with shoulder range of motion and grip. RESULTS: People with fibromyalgia had significantly higher increases in pain, cognitive fatigue, and physical fatigue when compared to healthy controls after completion of a cognitive fatigue task, a physical fatigue task, or a dual fatigue task (P < 0.01) with the exception of perceived cognitive fatigue during the cognitive fatigue task. People with fibromyalgia performed equivalently on measures of physical performance and cognitive performance on the physical and cognitive fatigue tasks, respectively. CONCLUSION: These data show that people with fibromyalgia show larger increases in pain, perceived cognitive fatigue, and perceived physical fatigue to both cognitive and physical fatigue tasks compared to healthy controls. The increases in pain and fatigue during cognitive and physical fatigue tasks could influence subject participation in daily activities and rehabilitation.