A recent study published in The Journal of Neuroscience (Nov. 17th 2004) has revealed that people who suffer from chronic back pain (CBP) for one year may experience a reduction in the brain's gray matter equivalent to the amount lost by the average person in 10 to 20 years of normal aging.  "Gray matter" refers to the darker-colored tissue of the brain, which is composed of the bodies of neurons. Gray matter is considered by many to be the "thinking" center of the brain, and is responsible for functions such as memory and information processing.

In the study, investigators compared 26 chronic back pain (CBP) patients with 26 matched normal volunteers. The CBP patients experienced unrelenting pain for one year, "primarily localized to the lumbosacral region including buttocks and thighs.  The normal decrease in gray matter volume was found to be 2.8 cm3 (0.5%) per year in both groups. After adjusting for age and gender factors an 11 percent decrease in gray matter volume for those with CBP. In addition, the more years someone had chronic back pain, the more loss of gray matter they suffered.

From their findings, the authors arrived at several conclusions:

"Our studies show that CBP (sustained for six months) is accompanied by abnormal brain chemistry, mainly a reduction in the N-acetyl-aspartate-creatine ratio in the prefrontal cortex, implying neuronal loss or dysfunction in this region and reduced cognitive abilities on a task that implies abnormal prefrontal processing.

"Our results demonstrate regionally specific reduced gray matter in patients with CBP. At the whole-brain level, this reduction is related to pain duration, regionally depends on multiple pain-related characteristics, and is more severe in the neuropathic sub-type.

"Given that normal whole-brain gray matter atrophy is 0.5% per year of aging and that atrophy caused by CBP is 5-11%, the magnitude of brain gray matter atrophy caused by CBP is equivalent to 10-20 years of aging. However, this analogy only holds for the overall magnitude, because the regional specificity of atrophy in CBP is distinct from that seen with aging."

While this study opens the door for significant speculation, it tends to generate more questions than it answers. From a chiropractic standpoint, it is easy to see why chronic back pain can cause additional symptoms beyond those that would be considered mechanical in nature. These findings most certainly serve as a serious warning to patients with back pain to seek care as soon as possible in order to prevent the condition from becoming chronic.   

Dr. Daryl Rich