Scientists reported Wednesday that they were able to "see" pain on brain scans and, for the first time, measure its intensity and tell whether a drug was relieving it. Though the research is in its early stages, it opens the door to a host of possibilities.
Scans might be used someday to tell when a baby, someone with dementia or a person unable to talk is feeling pain. They might lead to new, less addictive pain medicines. They might even help verify disability claims.
"Many people suffer from chronic pain and they're not always believed. We see this as a way to confirm or corroborate pain if there is a doubt," said Tor Wager, a neuroscientist at the University of Colorado, Boulder.
He led the research, published in the New England Journal of Medicine, on pain felt through the skin - heat applied to an arm.
Independent experts say the research shows a way to measure objectively what is now one of life's most subjective experiences.
Although many studies have found brain areas that light up when pain is present, the new work is the first to develop a combined signature from all these signals that can be used to measure pain.
"This is very exciting work. They made a huge breakthrough in thinking about brain patterns," said Dr. David Shurtleff, acting deputy director of the National Institute on Drug Abuse, which helped sponsor the research.
The research involved four experiments at Columbia University. In all, 114 healthy volunteers were paid $50 to $200 to be tested with a heating element placed against a forearm at various temperatures, not severe enough to cause burns or lasting damage.
The first set of experiments on 20 people developed signatures for pain versus the anticipation of it or mild warmth on the arm. The second experiment validated these signatures in 33 other people and found they predicted how much pain they said they felt.