http://www.dental.am/more.php?id=4717_0_1_0_C
Nov 23, 04
The
presence of chronic back pain is associated with a loss of gray matter in the
brain similar to that seen in the normal aging process, new research suggests.
Because, by definition, chronic pain has adverse effects on mood and increases stress, one
explanation is that tissue atrophy is caused by toxic and inflammatory
mechanisms, lead author Dr. A. Vania Apkarian, from Northwestern
University Institute of Neuroscience in Chicago, said in a statement.
As reported in the Journal
of Neuroscience, Apkarian's team used magnetic resonance imaging (MRI) to
compare the brains of 26 patients with chronic back pain with those of 26
matched "controls" without such pain.
Gray-matter volume was reduced by up to 11 percent in back pain patients
compared with controls, the investigators found. They estimate that between 10
and 20 years of normal aging would be needed to see this amount of loss.
A direct association was noted between pain duration and gray matter loss. For
each year of chronic pain, a 1.3-mL drop in gray matter volume occurred, the
authors point out.
This is the first study to show brain tissue abnormalities in patients with
chronic pain, the researchers note.
It will be important in future studies to correlate gray matter changes with
specific types of chronic back pain, which may help to better characterize this
brain loss, they add.
SOURCE: Journal of Neuroscience, November 23, 2004.