“It is the first time researchers have decoded the brain activity underlying chronic pain in patients, raising hopes that brain stimulation therapies already used for Parkinson’s and major depression can help those who have run out of other options. ‘What we’ve learned is that chronic pain can successfully be tracked and predicted in the real world, while patients are walking the dog, or at home, when they get up in the morning, and when they are going about their lives,’ said Prasad Shirvalkar, a neurologist and lead researcher on the project at the University of California, San Francisco.”—”Scientists discover brain signals for chronic pain. Discovery of ‘objective biomarker’ raises hopes for new treatments for people living with intractable pain.”

“Chronic pain syndromes are often refractory to treatment and cause substantial suffering and disability. Pain severity is often measured through subjective report, while objective biomarkers that may guide diagnosis and treatment are lacking. Also, which brain activity underlies chronic pain on clinically relevant timescales, or how this relates to acute pain, remains unclear. Here four individuals with refractory neuropathic pain were implanted with chronic intracranial electrodes in the anterior cingulate cortex and orbitofrontal cortex (OFC). Participants reported pain metrics coincident with ambulatory, direct neural recordings obtained multiple times daily over months. We successfully predicted intraindividual chronic pain severity scores from neural activity with high sensitivity using machine learning methods. Chronic pain decoding relied on sustained power changes from the OFC, which tended to differ from transient patterns of activity associated with acute, evoked pain states during a task. Thus, intracranial OFC signals can be used to predict spontaneous, chronic pain state in patients.”—”First-in-human prediction of chronic pain state using intracranial neural biomarkers”