A US study recently discussed on Reuters has found that the brains of people in chronic pain show a state of constant activity in areas that should be at rest. The researchers said in their Journal of Neuroscience article that chronic pain seems to alter the way people process information that is unrelated to pain, even with “minimally demanding attention tasks completely unrelated to pain”.Dante Chialvo, a researcher from Northwestern University in Chicago and a member of the team who worked on the study, said:
“People with chronic pain — meaning pain that lasts more than six months after their injury — have many other issues that affect their quality of life as much as pain. It is not known where they come from.”
The article says that recent studies have shown that in healthy people, certain regions of the brain take over during a resting state, something known as a default mode network. Chialvo said in a telephone interview that “It takes care of your brain when your brain is at rest”. When a person performs a task, this network quiets down, he said, but not in people with chronic pain. Instead, a front region of the cortex that is mostly associated with emotion is constantly active, disrupting the normal equilibrium.
Chialvo and his team did fMRI (functional Magnetic Resonance Imaging) scans on 15 people with chronic back pain and 15 healthy people. The particpants were given the simple task of tracking a moving bar on a computer screen so the researchers could observe their brains shifting out of default mode to handle the task. Both groups performed the task well but the scans showed different results. Chialvo said:
“Where we were surprised is the difference in how much brain they used to do the task compared with the healthy group. It was 50 times larger,”
Disruptions in this default network could explain why pain patients have problems with attention, sleep disturbances and even depression.
“These findings suggest that the brain of a chronic pain patient is not simply a healthy brain processing pain information but rather it is altered by the persistent pain in a manner reminiscent of other neurological conditions associated with cognitive impairments”.
