Figure 2.
A) Regional cerebral blood flow (rCBF) in response to a low intensity pressure stimulus at the metacarpophalangeal (MCP) joints in rheumatoid arthritis (RA) patients and pain-free controls. B) rCBF in response to a high intensity pressure stimulus at the MCP joints in RA patients and pain-free controls. C) The high intensity MCP stimulus led to significant increases in rCBF in the medial frontal cortex among RA patients but not among healthy controls. Bars represent the standard error of the mean.