Distinct brain activity patterns found in chronic pain

A recent study has identified signatures of electrical activity in the brains of people with chronic pain, which could lead to more effective treatments in the future. Chronic pain affects over 30% of the global population and existing therapies have limited effectiveness. The study, conducted by Prasad Shirvalkar at the University of California, San Francisco, and his colleagues, implanted electrodes and stimulators into the brains of four people with chronic pain as a result of a stroke or amputation. The researchers recorded electrical activity in the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC), brain regions associated with the potentially long-term emotional and cognitive aspects of pain. The participants answered surveys on the severity of their pain multiple times a day and pressed a button that took a 30-second recording of the activity in their OFC and ACC. Machine learning linked these electrical signals to the participants’ self-reported pain severity, and identified neural patterns that indicated whether the individual was experiencing a high or low pain state. The OFC was found to be more linked to chronic pain, while activity in the ACC was associated with acute discomfort. The researchers hope that this finding will motivate other researchers to study the OFC for chronic pain relief, and test whether non-invasive stimulation to the OFC helps to ease ongoing discomfort. The study is an early step towards uncovering the brain patterns that are linked to pain, which could lead to the development of more effective treatments in the future.