When the brain expects pain: common neural responses to pain anticipation are related to clinical pain and distress in fibromyalgia and osteoarthritis

• Published in: The European journal of neuroscience Vol. 39; no. 4; pp. 663 - 672
• Main Authors: Brown, Christopher A., El-Deredy, Wael, Jones, Anthony K. P.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.02.2014; Blackwell
• Subjects: Adult; Aged; Anticipation, Psychological; Biological and medical sciences; Case-Control Studies; chronic pain; Chronic Pain - physiopathology; electroencephalography; event-related potentials; Evoked Potentials, Somatosensory; expectancy; Female; Fibromyalgia - physiopathology; Fundamental and applied biological sciences. Psychology; human; Humans; Male; Middle Aged; Osteoarthritis - physiopathology; Prefrontal Cortex - physiology; Prefrontal Cortex - physiopathology; Vertebrates: nervous system and sense organs; Human; Chronic; chronic pain; Pain; Central nervous system; Electrophysiology; Electroencephalography; expectancy; event-related potentials; Event evoked potential; Encephalon; electroencephalography; human
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.12420

Supraspinal processes in humans can have a top‐down enhancing effect on nociceptive processing in the brain and spinal cord. Studies have begun to suggest that such influences occur in conditions such as fibromyalgia (FM), but it is not clear whether this is unique to FM pain or common to other forms of chronic pain, such as that associated with osteoarthritis (OA). We assessed top‐down processes by measuring anticipation‐evoked potentials and their estimated sources, just prior (< 500 ms) to laser heat pain stimulation, in 16 patients with FM, 16 patients with OA and 15 healthy participants, by using whole‐brain statistical parametric mapping. Clinical pain and psychological coping factors (pain catastrophizing, anxiety, and depression) were well matched between the patient groups, such that these did not confound our comparisons between FM and OA patients. For the same level of heat pain, insula activity was significantly higher in FM patients than in the other two groups during anticipation, and correlated with the intensity and extent of reported clinical pain. However, the same anticipatory insula activity also correlated with OA pain, and with the number of tender points across the two patient groups, suggesting common central mechanisms of tenderness. Activation in the dorsolateral prefrontal cortex was reduced during anticipation in both patient groups, and was related to less effective psychological coping. Our findings suggest common neural correlates of pain and tenderness in FM and OA that are enhanced in FM but not unique to this condition. Supra‐spinal processes in humans can exert a top‐down enhancing effect on nociceptive processing in the brain and spinal cord. Studies have begun to suggest such influences occur in conditions such as fibromyalgia (FM), but it is not clear if this is unique to FM pain or common to other forms of chronic pain, such as that associated with osteoarthritis (OA).