Pain can be objectively measured in patients for the first time ever by examining scans of their brains, according to scientists at the University of Colorado Boulder.
Researchers say the findings could lead to the development of reliable methods to measure pain, allowing doctors to objectively understand the amount of pain a patient is suffering instead of relying solely on their description.
The study, which was published this week in the New England Journal of Medicine, could also lead to new clues about how the brain generates different types of pain, as well help generate methods to objectively measure anxiety, depression, anger and other emotional stress.
“Right now, there’s no clinically acceptable way to measure pain and other emotions other than to ask a person how they feel,” said Tor Wager, associate professor of psychology and neuroscience at CU-Boulder and lead author of the paper.
To establish a technique, the research team used computer data-mining techniques to study images of 114 brains that were taken when the subjects were exposed to multiple levels of heat, ranging from benignly warm to painfully hot.
Eventually, the scientists identified a distinct neurologic signature for the pain.
“We found a pattern across multiple systems in the brain that is diagnostic of how much pain people feel in response to painful heat.” Wager said.
The also found that a pain signature was not unique to an individual as they originally believed, but that the pain signature was transferable between people with 90% – 100% accuracy, even with no prior brain scan of the individual.
“The findings could lead to the development of reliable methods to measure pain, allowing doctors to objectively understand the amount of pain a patient is suffering instead of relying solely on their description.”
The signature is specific to physical pain, but past studies have shown that social pain can look very similar to physical pain in terms of brain activity.
The scientists also discovered that the neurologic signature also showed when a painkiller had been administered by registering a decrease in pain.
The study lays the foundations for future work that could produce the first objective tests of pain by doctors and hospitals. Wager and his colleagues are now testing how the neurologic signature holds up when applied to different types of pain.
“I think there are many ways to extend this study, and we’re looking to test the patterns that we’ve developed for predicting pain across different conditions,” Wager said.
He also said that this technique is not suitable for measuring chronic pain, but that it may be an ‘ingredient’ of chronic pain.
“Understanding the different contributions of different systems to chronic pain and other forms of suffering is an important step towards understanding and alleviating human suffering,” Wager added.
The study was funded by the National Institute on Drug Abuse, the National Institute of Mental Health and the National Science Foundation.