Mechanisms underlying chronic back painBMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6956.681 (Published 17 September 1994) Cite this as: BMJ 1994;309:681
- M I V Jayson
STUDIES ARE LOOKING AT THE BRAIN AND SPINAL CORD
Back pain is one of the main causes of disability. Population studies indicate a lifetime prevalence of 58%.1 For many these are frequent episodes of acute pain with only temporary periods of disability. Some people, however, develop chronic pain and become severely disabled. Although this may be due to persistence of the original nociceptive insult, in many cases the mechanism of chronic pain is different from that of acute pain and a new pathology has developed that leads to chronicity.
Abnormalities in the lumbar spine are common, and degenerative changes are be found in virtually all older people. But correlation is poor between back pain and degenerative changes seen in radiographs and magnetic resonance imaging scans.2,3
Ever since disc herniation was originally described it has been identified as a potent cause of back trouble.4 Undoubtedly there are some such patients who have pain in a nerve root distribution, with clear evidence of dural tension with limited straight leg raising and specific neurological signs. Many, however, do not meet these criteria. Without such unequivocal evidence it is still common to incriminate a herniation seen on magnetic resonance imaging if it coincides with …