By Tracie White
Photography by Norbert von der Groeben
It was a simple, painful experiment.
How painful? That’s exactly what the experiment set out to discover.
“People have been looking for a pain detector for a very long time,” says Sean Mackey, MD, PhD, who led the project to develop the first “painometer.” “We rely on patients self-reporting for pain, and that remains the gold standard. But there are a large number of patients, particularly among the very young and the very old, who can’t communicate their pain levels.
“We’re hopeful we can eventually use this technology for better detection and better treatment of chronic pain,” adds Mackey, chief of the Division of Pain Management and associate professor of anesthesia. He published the study Sept. 13, 2011, in PLoS ONE.
Mackey and his colleagues scanned the brains of eight subjects, using functional magnetic resonance imaging. To induce some pain, they applied a heated probe to the subjects’ forearms. The team recorded brain patterns both with and without pain, and used the patterns to train a computer algorithm to create a model of what pain looks like.
The computer was then asked to consider the brain scans of eight new subjects and determine whether they had thermal pain.
“It did amazingly well,” says co-author Neil Chatterjee, currently an MD/PhD student at Northwestern University. The computer was successful 81 percent of the time.
The idea for this study arose at a 2009 Stanford Law School forum on how the neuroimaging of pain could be used and abused in the legal system. Mackey attended with two of his lab assistants — Chatterjee and Justin Brown, PhD, now an assistant professor at Simpson College.
“At the end of the symposium, there was discussion about the challenges of creating a painometer. I discussed hypothetically how we could do this in the future,” Mackey says. Afterward, Chatterjee and Brown decided to give it a shot.
“It was very much on a whim,” says Chatterjee. “We thought, maybe we can’t make the perfect tool, but has anyone ever really tried doing this on a very, very basic level? It turned out to be surprisingly simple to do this.”