Brain Can Generate Pain without Stimulus

A study has found that after volunteers were hypnotized into believing they felt pain, they showed similar brain activity to those volunteers subjected to genuine pain produced by pulses of heat (48.5oC).

The study, conducted by researchers at the University of Pittsburgh (PA, USA) and the University College of London (UCL, UK), provides new evidence for the basis of "functional pain” such as chronic low back pain, fibromyalgia, and other disorders where the pain cannot be traced to a physical problem.

The researchers used a magnetic resonance imaging (MR) brain scanner to take pictures of brain function while subjects were hypnotized. A third group of volunteers who were asked to imagine they were experiencing the same pain had significantly lower brain activity than the hypnotized and genuine pain groups. The results of the study were published in the July 23, 2004, online issue of NeuroImage.

"This study provides direct evidence of the brain generating pain in the absence of any actual noxious input,” said Stuart Derbyshire, Ph.D., assistant professor of anesthesiology and radiology at the University of Pittsburgh and one of the principal investigators. "This is significant because many functional disorders, such as fibromyalgia, might rely upon similar mechanisms. We are currently running studies to test that idea with patients.”




Related Links:
U. of Pittsburgh
U. College of London