Colleagues in the pain treatment community were largely impressed by the quality of Wasan's research but said it was still early.
"If this were a board game, this is three steps down the Chutes and Ladders with thousands of steps to go," said Dr. Perry G. Fine, a pain specialist at the University of Utah in Salt Lake City. "You never get anywhere unless you take the first step. It's a really important step."
He said the brain imaging technique "allows for us to understand how chronic pain differs from acute pain. You see parts of the brain light up where there's increased neural activity that normal people don't have and probably cannot begin to express or imagine."
"Pain is still as complicated as it's ever been," he said. Having a tool to observe brain activity during chronic pain means doctors "can now have a bit more trust and believe in what the patient says" when they describe their pain. However, he cautioned that economic and other factors leave physicians a long way from "being able to put everyone in a scanner."
While praising Wasan's research as well-planned and well-executed, and saying it provided "a valuable tool in gaining information about processes in the brain," Dr. Alex Cahana, chief of the division of pain medicine at the University of Washington in Seattle, also found it problematic.
"It perpetuates the idea that we need to look at imaging in order to validate pain," said Cahana, an anesthesiologist who uses a combination of pills, injections, motivational interviews and guidance to help patients live a happier life with their pain. "At the end of the day, the imaging of pain … does not explain to us a cause of pain. It doesn't explain why the pain is chronic."