Back pain linked to premature aging

Chronic back pain afflicts millions and can make people depressed and anxious. Unrelenting pain, however, may affect more than our moods. It may also age us prematurely by causing brain shrinkage equivalent to decades of normal aging, researchers have found.

“The long-term damage can trigger a self-perpetuating cycle of pain, making the condition more intractable,� says A. Vania Apkarian, lead author of the study and a pain specialist at the Northwestern University Feinberg School of Medicine in Chicago.

About one in four Americans experiences back pain some time in life, but for about 25% of these people, the pain becomes chronic and unremitting. Although scientists knew that nerves and the spinal cord changed in chronic pain conditions, it was assumed that once the pain eased, the brain returned to normal, Apkarian says. This study found otherwise.

Using MRIs, researchers compared the brain images of 26 participants with chronic back pain with those of 26 normal volunteers of the same age and gender. The scans revealed that the volume of gray matter in the prefrontal cortex and thalamus -- the brain regions that regulate thinking, information processing, memory, social behavior and decision-making -- was diminished by 5% to 11% in chronic pain sufferers, the rough equivalent of 10 to 20 years of normal aging. The subjects lost an average of 1.3 cubic centimeters of gray matter for every year they were in pain, in addition to the usual reduction from aging. While researchers don’t know exactly what sparks this atrophy, they suspect the cumulative stress of coping with pain wears out brain nerve cells.

The study was published in Tuesday’s issue of the Journal of Neuroscience.