Gray matter in the brain may shrink by 11% in 1 year for individuals with chronic back pain. The percentage is the same amount of brain density that is lost in 10 to 20 years of normal aging, according to the results of a study reported in the November 23, 2004, issue of The Journal of Neuroscience. Gray matter is the part of the brain that processes memory and function.
The study included 52 people (n = 26 with chronic back pain, and n = 26 healthy participants). The patients with chronic back pain had experienced constant pain for more than a year. Using structural magnetic resonance imaging and other analytic methods to compare the brain images of both groups, the researchers found that every year of chronic pain resulted in a loss of 1.3 cm3 of gray matter. The researchers said it is possible that some of the gray matter loss in individuals with chronic back pain happens without substantial loss of neurons. They recommended that proper treatment could reverse at least some of the gray matter loss.