In response to clinically relevant joint pain evoked by pressure applied to the metacarpophalangeal joint, neural processing in the medial frontal cortex increases and is directly associated with clinical pain in patients with rheumatoid arthritis (RA). This according to a recent study that aimed to explore the mechanisms underlying pain in patients with RA and to identify brain signals that may serve as imaging markers for developing targeted treatments for RA‐related pain. Patients with RA and matched control subjects underwent functional magnetic resonance imaging, using pulsed arterial spin labeling. The imaging conditions included resting state, low‐intensity stimulus, and high‐intensity stimulus. Researchers found:

• Among RA patients, regional cerebral blood flow (rCBF) in the medial frontal cortex and dorsolateral prefrontal cortex increased during both low‐pressure and high‐pressure stimulation.
• No rCBF changes were observed in pain‐free controls.
• Region‐of‐interest analyses in RA patients showed that baseline rCBF in the medial frontal cortex was negatively correlated with the pressure required for the high‐intensity stimulus and positively correlated with pain induced by the low‐intensity stimulus.
• Regional CBF during high pain was positively correlated with pain severity and pain interference.