In a provocative new study, scientists reported yesterday 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. While the research is in its early stages, it opens the door to a host of possibilities.
Scans might be used someday to tell when pain is hurting a baby, someone with dementia or a paralyzed person unable to talk. They might lead to new, less addictive pain medicines. They might even help verify claims for disability.
"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.
So far the study is only on pain felt through the skin -- heat applied to an arm. More needs to be done on more common kinds of pain, such as headaches, bad backs and pain from disease.
Pain is the top reason people see a doctor, and there's no way to quantify how bad it is, other than what they say. A big quest in neuroscience is to find tests or scans that can help diagnose ailments with mental and physical components such as pain, depression and post-traumatic stress disorder.
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 the signals that can be used to measure pain.
"They made a huge breakthrough in thinking about brain patterns," said Dr. David Shurt-leff, acting deputy director of the National Institute on Drug Abuse, which helped sponsor the research. "We need a brain-based signature for pain."
The research involved four experiments at Columbia University that ensured no harm to volunteers. They were paid to have a heating element placed against a forearm at various temperatures. Some were required to stand it for 10 to 20 seconds. Functional magnetic resonance imaging, or fMRI scans recorded changes in brain activity as measured by blood flow. Computers were used to generate signatures or patterns from these readings.