You would expect the fMRIs of the chronic pain group and the healthy control group to be similar, because everyone was performing the same task, requiring activation of the same part of the brain.
But there were distinct differences in the blood flow through the brains of the pain patients and the healthy comparisons. Specifically, parts of the brain in the chronic pain patients that should have been “at rest” during the task remained active. So even though those in the chronic pain group performed the task as well as the others, their brains behaved differently.
Studies like these paint a picture of how the brains of chronic pain patients are functionally different than those of healthy people. Indeed, the researchers noted that “these findings suggest that the brain of a chronic pain patient is not simply a healthy brain processing pain information, but rather is altered by the persistent pain in a manner reminiscent of other neurological conditions associated with cognitive impairments.”
Since the brain controls emotions, sleep, and other behaviors, these may also be affected by chronic pain. Indeed, people in chronic pain are known to suffer from increased depression, anxiety, sleep difficulties, and “fuzzy thinking,” as well as a decreased quality of life.4 They also tend to suffer from a lack of motivation. For example, no matter how often their doctors, therapists, families, and friends encourage them to exercise, many people in chronic pain just can’t seem to make themselves do it. Often, just getting through the day is a struggle for them. Until recently, we had no idea why chronic pain patients suffered from a lack of motivation, “fuzzy thinking,” and other problems, and we had no way of connecting these problems to the pain. But that’s all changing, now that researchers have discovered links between chronic pain and specific parts of the brain, like the following:
7 Best Yoga Poses For Chronic Pain Photo Gallery
Chronic Pain Dampens the Motivation Centers of the Brain—In a fascinating study conducted by Stanford University researchers,5 laboratory mice were trained to poke their noses through a certain hole in their cages when they were hungry. At the beginning of the study, it only took one nose poke to be rewarded with a food pellet. Over time, the mice had to poke their noses through the hole more and more often to get the food. In other words, it became increasingly difficult and required more motivation to get the food.
After the mice had learned to poke their noses through the hole to get food, the researchers turned some of them into “chronic pain patients” by damaging a paw. Within a week after the pain began, the “chronic pain mice” were less and less likely to work hard for food, compared to the healthy mice. Even when the “chronic pain mice” were given pain medication and could move about easily, they continued to be less motivated and less likely to work for their food.
To find out why, the researchers examined the mice brains and discovered that chronic pain had triggered permanent alterations in the nucleus accumbens, a part of the brain that motivates us do things that improve our chances of survival, and to avoid things that hamper those chances.
Here was solid proof that chronic pain can alter specific regions of the brain and produce harmful results. To make matters worse, in addition to altering the brain physically and functionally, chronic pain can hamper its ability to adapt in helpful ways.
Chronic Pain Slows Learning—Australian researchers asked a group of people suffering from chronic tension-type headaches (CTTH) to perform a learning task in which they moved their thumbs in a specified direction as rapidly as possible.6 Typically, when people are asked to do this, they get better at it with practice, and the adaptations of the brain as it masters this skill can be tracked. However, the chronic pain patients did not improve their ability to perform the skill, and there were no changes in their brains, suggesting that their brains were unable to adapt sufficiently to master the new skill. This study demonstrates that chronic pain can slow or otherwise interfere with the positive process of neuroplasticity.
We still have a lot to learn, but this much is certain: Chronic pain is not a simple matter of the brain sending out too many “Danger, there’s a problem with your back!” messages, like a phone that keeps ringing because some wires have been crossed somewhere in the system With chronic pain, the brain has truly changed, and significantly so. It has physically reorganized itself around the experience of pain, and is literally compelled to keep that pain alive. It’s become a “pain brain.”