A comparison of two-point discrimination threshold of tactual, non-painful stimuli between chronic low back pain patients and controls.

Differences in pain sensitivity between chronic pain patients and healthy controls have been reported. Seltzer and Seltzer extended this line of research in studying the sensitivity to non-painful stimuli. They reported that the 2-point discrimination threshold of chronic pain patients was higher than that of control subjects. However, the study of Seltzer and Seltzer suffered from several methodological shortcomings. Therefore, in the present study we tried to replicate the findings in a group of chronic low back pain patients using a design that was believed to be methodologically stronger. Replication failed: no evidence was found for the hypothesis that chronic pain patients are less sensitive to non-painful stimuli. Further studies on various defined types of acute and chronic pain patients are required.