January 6, 2005

Research: Chronic back pain shrinks brain

By Elizabeth Crown

Chronic back pain, a condition afflicting many Americans, shrinks the brain by as much as 11 percent — equivalent to the amount of gray matter lost in 10 to 20 years of normal aging, a research study found. 

Loss in brain density is related to pain duration, indicating that 1.3 cubic centimeters of gray matter (the part of the brain that processes information and memory) are lost for every year of chronic pain, said lead researcher A. Vania Apkarian, associate professor of physiology and a researcher at the Institute of Neuroscience.

The study, the first to examine brain changes in chronic pain conditions, was published in the The Journal of Neuroscience.

At least 25 percent of Americans suffer from back pain; in one fourth of these individuals, the pain is chronic.

Although chronic pain greatly diminishes quality of life and increases anxiety and depression, it previously had been assumed that the brain reverts to its normal state after chronic pain stops.

Apkarian and co-researchers used structural magnetic resonance imaging brain scan data and two automated analysis techniques to contrast brain images from 26 participants with back pain with those from matched normal subjects.