Brain marker can predict chronic pain

People who have a particular abnormality in their brain structure are more likely to develop chronic pain after a lower back injury, says research published in Pain.

US scientists carried out MRI scans on 46 people who had developed a lower back injury in the past four weeks but had not experienced any back pain in the previous year. A year later MRI scans were redone. By then, half of the patients had improvements in their back pain (regardless of any treatment they had).

The scans showed that people who had persistent back pain had the same structural abnormality “markers” in their brains at the onset of injury and one year later. The marker in the axons of the brain actually allowed the scientists to predict back pain with up to 85% accuracy.

“The abnormality makes them vulnerable and predisposes them to enhanced emotional learning that then amplifies the pain and makes it more emotionally significant,” says Prof A Vania Apkarian who led the research. “We’ve found the pain is triggered by these irregularities in the brain. We’ve shown abnormalities in brain structure connections may be enough to push someone to develop chronic pain once they have an injury.”

The findings could result in changes in the way doctors treat patients for pain.