Pain: Placebo’s sweet hot spot in the brain identified
Last Updated on February 13, 2018 by Joseph Gut – thasso
November 17, 2016 – There is good news for seriously pain ridden patients worldwide. Scientists have identified for the first time the region in the brain responsible for the “placebo effect” in pain relief, when a fake treatment actually results in substantial reduction of pain, according to newest research. In fact, pinpointing the sweet spot of the pain killing placebo effect could result in the design of more personalized medicine for the 100 million Americans and the many more millions of patients worldwide with chronic pain.
The fMRI technology developed for the study has the potential to usher in an era of individualized pain therapy by enabling targeted pain medication based on how an individual’s brain responds to a drug. The finding also will lead to more precise and accurate clinical trials for pain medications by eliminating individuals with high placebo response before trials.
The scientists discovered a unique brain region within the mid frontal gyrus that identifies placebo pill responders in one trial and can be validated (95 percent correct) in the placebo group of a second trial (see links below for the clinical trials).
Using drugs to treat patients’ pain has been trial and error, with physicians changing dosage or trying another type of drug if one doesn’t work. The new technology will allow physicians to see what part of the brain is activated during an individual’s pain and choose the specific drug to target this spot. It also will provide more evidence-based measurements. Physicians will be able to measure how the patient’s pain region is affected by a drug or a drug candidate.
Currently, placebo response is primarily studied in healthy subjects within controlled experimental settings. While such experiments aid understanding of the biological and behavioral underpinning of placebo response in experimental (applied) pain, they translate poorly to the clinic, where pain is mainly chronic in nature.
In this new study and for the first time, scientists used functional magnetic resonance imaging (fMRI) combined with a standard clinical trial design to derive an unbiased brain-based neurological marker to predict analgesia associated with placebo treatment in patients with chronic knee osteoarthritis pain. Scientists showed placebo pill ingestion is associated with a strong analgesia effect, with more than half of the patients reporting significant pain relief.
If future similar studies can further expand and eventually provide a brain-based predictive best-therapy option for individual patients, it would dramatically decrease unnecessary exposure of patients to ineffective therapies and decrease the duration and magnitude of pain suffering and opioid use, with all the associated abuse that goes with the latter.
Pascal Tétreault, Ali Mansour, Etienne Vachon-Presseau, Thomas J. Schnitzer, A. Vania Apkarian, Marwan N. Baliki. Brain Connectivity Predicts Placebo Response across Chronic Pain Clinical Trials. PLOS Biology, 2016; 14 (10)
Clinical Trials conducted in the course of the reported study