September 13th, 2011
06:07 PM ET
Your arm hurts, but it's difficult for someone else to say just how much it really hurts. Scientists have been searching for a way to measure pain and new research suggests they are getting closer.
Researchers at Stanford University trained a computer algorithm to interpret magnetic resonance imaging (MRI) data of the brain and determine the presence of pain, according to a new study published Tuesday in the online journal PLoS ONE.
Researchers applied heat directly to the forearms of 8 study participants. The subjects reported a pain score of 7 out of 10 pain, when the temperature their skin was exposed to reached about 115 degrees Fahrenheit.
While the participants were undergoing this heat exposure, MRI scanners tracked their brain activity. Then the computer compared data when participants were undergoing MRIs without experiencing any pain.
The computer algorithms effectively learned how to recognize the difference between pain and non-pain in the human brain.
When presented with additional sets of brain scans from sixteen new participants, the computer algorithm correctly identified about 80% of the time which brains were experiencing pain, and which were not.
Researchers have long known that pain registers on MRI scans, but having a computer algorithm positively predict the difference between a brain with pain and a brain without pain is new ground.
"I had been convinced for many years that the very subjective nature of pain would preclude it from being able to characterize a pattern of brain activity that would extend across other individuals to discriminate pain or not pain," says Dr. Sean Makey, a senior author of the study. "I was really surprised to see that you could."
The researchers behind this study have already started another, similar study, and with a larger number of participants.
The technology seems to work in a controlled laboratory setting, but in real-world situations there are lots of complicating factors. For example, other types of pain in other parts of the body may register differently, and this study does not attempt to measure varying degrees of pain. And those suffering from chronic pain would not be able to provide a baseline pain-free brain scan for comparison.
"I'm hoping that we will see this technology as an objective biomarker of treatment responsiveness for clinical trials when testing a particular therapy or drug," says Makey. "This will augment the patient's recorded pain, and give us a more objective measure of how we're actually impacting their pain and their pain system."
From around the web
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.