Guidelines Discourage Using Brain Imaging as a Test for Chronic Pain

Recent advances in brain imaging have improved understanding of acute and chronic pain, but have led to an increased in the demand to use this data for insurance and medical legal cases. However, a task force is advising against the use of brain imaging as a “lie detector” test for chronic pain.

The new guidelines from the group of global researchers was published in Nature Review: Neurology. The task force consisted of clinicians, brain imaging researchers, and experts in functional magnetic resonance imaging, neuroethics, and law.

"It's not possible at this point in time to say with any degree of certainty that a person does or does not have chronic pain based on brain imaging," Karen Davis, PhD, of the Krembil Research Institute at the University Health Network in Toronto, Ontario, Canada, said in a statement. "The only way to truly know if someone is in pain is if they tell you because pain is subjective and it is a complex experience. No brain scan can do that."

Davis said the use of brain imaging as a “lie detector” test for chronic pain is “inappropriate and unethical” since the technology is not foolproof and there are differences not only between people, but within the same person at different times. The variability of pain experience makes it a challenge to use brain imaging as an objective biomarker of chronic pain, the task force wrote in the report.

Future use of brain imaging data may raise ethical and legal questions regarding treatment decisions and employment opportunities. In addition, if brain imaging is used in legal cases, it will become public record, which may result in people making other inferences about the individual based on their brain evidence.

“Chronic pain is also the subject of many legal disputes between patients, healthcare systems and disability benefit providers, in which proof or disproof that a patient is or is not experiencing pain might affect payments,” the authors wrote. “Consequently, research to address whether chronic pain can be identified objectively is needed for a variety of reasons, particularly to provide evidence for insurance and legal purposes.”

According to the task force, the use of brain imaging to diagnose chronic pain is only in a discovery phase. Instead, brain imaging can be used to provide biomarkers of key characteristics related to chronic pain that then guide pain management. Furthermore, the task force recommended that brain-based biomarkers be used in addition to, not as a replacement for, subjective reports of experienced pain.

"We are working towards biomarkers for chronic pain, but the goal is not as a lie detector test but rather to help provide personalized pain treatment options for patients," Davis said. "We expect many people will be relieved that there is now a blueprint in place for moving forward with this research. People outside of the field of imaging might be disappointed, but the fact of the matter is the technology cannot be used to support or dispute a claim of chronic pain."