We hypothesized that change in pain threshold to pressure reflects a generalized change in the pain system affecting both tender and control points.
We assessed 18 tender points and 4 control points using an algometer in 60 patients with generalized fibromyalgia/fibrositis syndrome, 60 patients with localized chronic pain syndromes, and in 60 pain-free subjects.
A significant correlation was found between myalgia scores at tender points and control points in these subjects.
These results suggest that there is a diffuse change in pain modulation in fibromyalgia, as hypothesized, but the tender point is still clinically useful.