Pain is one of the most important and basic subjective experiences that a person can have; and there is plenty of evidence that pain perception takes place in the brain.
But there was a huge knowledge gap about where and how these signals are processed in the brain.
For the first time, researchers in the United States were able to record pain-related data from inside the human brain.
They studied patients who had chronic pain disorders caused by stroke or amputations (phantom limb pain).
Chronic pain affects at least 10% of the world population: approximately 60 million people. The causes are multiple: from arthritis, cancer and back problems to diabetes, stroke and endometriosis.
The data was collected by the researchers over months while the patients were at home and analyzed using machine learning tools.
In this way, the researchers identified a brain area associated with chronic pain and objective biomarkers of chronic pain in individual patients.
What they found are the brain signals that reveal the degree of a person’s pain.
They considered the research results a step forward toward radical new treatments for people suffering from debilitating chronic pain.
Because deciphering the brain activity underlying chronic pain in patients raises hope that brain-stimulating therapies already used for Parkinson’s and major depression could help those left without other options.
Although chronic pain has led to an increase in prescriptions for powerful opioids, no medical treatment works well for this ailment, leading experts to call for a complete rethink of the way healthcare services treat patients with pain. durable.
For the new study, Shirvalkar and his colleagues surgically implanted electrodes into four patients with intractable chronic pain.
The devices allowed patients to record the activity of two brain regions—the anterior cingulate cortex and the orbitofrontal cortex—with the push of a button on a remote control.
The orbitofrontal cortex is an area involved in emotion regulation, self-assessment, and decision-making.
Several times a day, the volunteers were asked to fill out brief surveys about the intensity and type of pain they were experiencing, and then snapshots of their brain activity were recorded.
Using the survey responses and brain recordings, the scientists found they could train an algorithm to predict a person’s pain based on electrical signals from their orbitofrontal cortex. “We have developed a target biomarker for that type of pain,” says Shirvalkar.
“Chronic pain isn’t just a longer-lasting version of acute pain, it’s fundamentally different in the brain,” Shirvalkar says.
“The hope is that as we better understand this, we can use the information to develop personalized brain stimulation therapies for the most severe forms of pain.”
Based on the findings, clinical trials could be carried out that evaluate the use of deep brain stimulation to control chronic pain.
Deep brain stimulation sends electrical impulses to the brain to disrupt problematic signals.
Because it involves brain surgery, that kind of stimulation is a treatment of last resort. But it is already used for Parkinson’s disease and major depressive disorder.
To be effective, doctors must know precisely what signs to treat.