No pain, healthier brain

Wiping out chronic pain in the lower back doesn’t just dull the agony. It allows the brain to recover, too. Six months after people’s backaches were eased, their brains showed fewer signs of the abnormalities that accompany chronic pain, a new study shows.

This brain recovery is “a concrete message that certainly brings hope and relief to those suffering from this condition,” says UCLA neuroscientist Dante Chialvo.

In the study, neuroscientist Laura Stone of McGill University in Montreal and colleagues scanned the brains of people who had experienced back pain for at least a year. Compared to healthy controls, chronic pain sufferers had thinning in the dorsolateral prefrontal cortex, a brain region that’s been linked to pain modulation. This region also showed abnormal activity when people with chronic back pain took a simple cognitive test while in a brain scanner, the team found.

But six months after treatment with either spine surgery or pain-relieving injections, scans revealed that the pain sufferers’ brains bounced back. Their thin dorsolateral prefrontal regions grew larger, and their brain activity began to look more normal. These brain changes depended on the level of pain relief: The less pain a person reported after treatment the greater the improvement, the team reports in the May 18 Journal of Neuroscience.

“We know that pain causes brain changes, and now we know that taking pain away reverses those changes,” Stone says.

It’s too soon to know exactly how pain reduction influences the brain, or vice versa, Stone says. But if it turns out that the dorsolateral prefrontal cortex controls pain, she says, clinicians might one day be able to reduce suffering by targeting the region with noninvasive techniques such as cognitive behavioral therapy, meditation or exercise.