Brain Imaging and the Treatment of Chronic Pain

At the 2018 American Academy of Pain Medicine Annual Meeting, Sean Mackey, MD PhD, Chief, Pain Medicine Division at Stanford University discussed the use of brain imaging in the treatment of chronic pain.

This session discussed brain imaging technologies to study chronic pain, research, use case application, and medicolegal considerations. A key question in the treatment of chronic pain centers around whether or not neuroimaging can be used to predict pain and treatment outcomes.

Pain is a product of the brain. There is a clear understanding of the areas of the brain impacted by pain. Brain biomarkers researchers ask, can we turn brain imaging into something useful for pain patients and providers? Possibly turn pain meters into an objective way of capturing pain. As we currently rely on self-report of pain to create a pain treatment plan and it remains the gold standard, furthering neuroimaging and marching learning can help patients and providers treat pain in a more accurate and planned way. This technology will ultimately drive individualized effective treatment. Keep in mind that self-reporting of pain can be limiting for vulnerable populations (young and aged).

Objective biomarkers for pain will offer development of personalized, safe and effective approaches to pain management.  Biomarker research includes the following:

• Diagnostic marker: Identifies a disease
• Predicative marker: Identifies risk factors for developing disorders and disease predisposition
• Prognostic marker: predicts outcome
• Stratification marker: predicts treatment response
• Efficacy marker: measures treatment response
• Toxicity marker: defects treatment toxicity/side effects
• Surrogate endpoint: measures outcome

Early research using high res structural MRI images, across multiple research institutions, show high accuracy, sensitivity, and specificity results.

A few points of interest regarding the current state of neuroimaging and pain management based on Dr. Mackey’s research and expertise are as following:

• Neuroimaging based pain detection should not be used to replace patient self-report of pain, but instead to augment/enhance.
• Brain-based biomarkers should be used as an adjunct to, rather than a replacement for subjective reports of the pain experience.
• Use of brain imaging as legal evidence of an individual’s pain is not advisable until the specificity and sensitivity of such tests are improved, and validated protocols exist.
• Current brain-based measures should be used only to understand brain mechanisms underlying pain, factors that lead to persistence of pain, and targets in the brain for safe and effective pain management.

While the legal community and some entrepreneurs will chose to use brain biomarkers outside the above recommendations, it is important to keep in mind how the researchers feel the research fits into practice and use case scenarios.

Dr. Mackey referenced a Consensus Statement published in September 2017, brain imaging tests for chronic pain: medical, legal and ethical issues and recommendations. The statement can be found here: https://www.nature.com/articles/nrneurol.2017.122