The Lateral Prefrontal Cortex Mediates the Hyperalgesic Effects of Negative Cognitions in Chronic Pain Patients

While high levels of negative affect and cognitions have been associated in chronic pain conditions with greater pain sensitivity, the neural mechanisms mediating the hyperalgesic effect of psychological factors in patients with pain disorders are largely unknown. In this cross-sectional study, we hypothesized that 1) catastrophizing modulates brain responses to pain anticipation, and that 2) anticipatory brain activity mediates the hyperalgesic effect of different levels of catastrophizing, in fibromyalgia (FM) patients. Using functional Magnetic Resonance Imaging, we scanned the brains of 31 FM patients exposed to visual cues anticipating the onset of moderately intense deep-tissue pain stimuli. Our results indicated the existence of a negative association between catastrophizing and pain-anticipatory brain activity, including in the right lateral prefrontal cortex (IPFC). A bootstrapped mediation analysis revealed that pain-anticipatory activity in lateral prefrontal cortex (IPFC) mediates the association between catastrophizing and pain sensitivity. These findings highlight the role of IPFC in the pathophysiology of FM related hyperalgesia, and suggest that deficits in the recruitment of pain-inhibitory brain circuitry during pain-anticipatory periods may play an important contributory role in the association between various degrees of widespread hyperalgesia in FM and levels of catastrophizing, a well validated measure of negative cognitions and psychological distress. Perspective This article highlights the presence of alterations in pain-anticipatory brain activity in FM. These findings provide the rationale for the development of psychological or neurofeedback-based techniques aimed at modifying patients' negative affect and cognitions towards pain