Treating chronic pain can reverse brain changes
CTV.ca News Staff
Published Monday, May 23, 2011 9:59PM EDT
Anyone who has ever suffered from chronic pain knows it can bring on depression and even problems with concentration and memory. In fact, researchers have found that long-term pain leads to physical changes in the brain.
New Canadian research has found that those brain changes can be reversed when the hurt is treated effectively.
In a study published this week in the Journal of Neuroscience, a group of pain researchers from McGill University and the McGill University Health Centre found that relieving pain actually causes physical brain changes they can see on a brain scan.
The research team looked at 18 people with chronic low-back pain who had been suffering for more than six months and who planned to undergo either long-acting pain reliever injections into the lower spine, or spinal surgery.
They then tested their brain responses to cognitive tests and examined their brains' structures. They also brought in a control group of 16 people without chronic pain and performed similar tests.
MRI scans were conducted on each subject that measured the cortical thickness of the brain and brain activity when the subjects were asked to perform a simple cognitive task.
The researchers found abnormal brain activity during an attention-demanding cognitive task. They also found one region of the brain, called the dorsolateral prefrontal cortex, was thinner in those with chronic pain compared to the healthy patients. This area of the brain plays a key role in mood, social judgment, short-term memory and higher-order thinking.
Anne Marie Hurteau was one of the patients studied. She had suffered from chronic pain for years after a fall left her with two displaced vertebrae. She says on a scale of one to 10, her pain was often a 12.
"The pain started in the mid part of my back, going down into my hip… and all the way to my big toe. It was like somebody had taken a torch and was burning me from the inside," she says.
She tried acupuncture, physiotherapy and other remedies before finally getting surgery. The surgery erased most of her pain, she says.
"Now, I have energy. I can do my day at work. I can be with my family. I can do sports. I can have a life. I didn't have a life for four years and now my life is back. So it does make a huge difference," she says.
Hurteau and the rest of the patients were all tested again six months after their surgery or pain reliever injections. (Only 14 of the subjects returned for the second round of tests.)
The researchers found there was increased cortical thickness in the areas of the brain related to both pain reduction and physical disability in most of the group.
The dorsolateral prefrontal cortex was no longer thinner in the group with pain compared to the control group, suggesting the brain tissue regenerated itself.
During the cognitive test, the differences that the researchers had observed in brain activation in the first round of tests disappeared.
Three of the 14 treated patients reported worse back pain or disability six months later. When researchers looked at their brain scans, their gray matter had not regenerated itself at all.
"Our results imply that treating chronic back pain can restore normal brain function," the authors conclude in their study, which appears in the Journal of Neuroscience.
Dr. Mary Lynch of the Canadian Pain Society said she finds the study results exciting because they add further evidence that pain can hurt the brain.
She says she knows the life-changing effects of appropriate pain treatment because she's seen it.
"People present to you with significant pain and if you treat it, that allows them a better quality of life, their level of function will improve not only physically, but cognitively."
"What this study adds to the literature is that if you treat that pain effectively then you can reverse the changes that you see in the brain, and you can also see improvements in the function," she added.
With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip