You can’t have pain without something getting on your nerve
Last week I explained what degenerative endplate sclerosis is and how clinicians describe this finding on an MRI report. However, what is the relationship of these MRI findings to back pain?
The vertebrae is a biologically active organ. It just doesn’t sit there. The inside of the bone is a meshwork of calcium and blood and marrow. It is in a constant flux of remodeling, breaking down and building up. When a bone is under stress, biologic signals are sent and the bone cells begin laying down more bone to reinforce the area. Radiographically, more bone equals more density which equals changes in the appearance of an xray, ct or MRI.
But how does this produce pain? Nerves are meant to convey signals to and from the brain. There are some nerves that are meant to carry signals such as light touch or vibration, while there are other nerves whose job it is to convey signals of pain and temperature to the brain. When the nerves that carry pain signals are stimulated or irritated, your brain perceives the pain and tries to remove you from that pain. For example, you don’t have to tell your hand to move away when you touch a hot pot. The pain fibers in your hand are overstimulated by the heat. A signal goes to your brain and the brain bypasses conscious thought and moves your hand away from the pot. After your hand is out of danger, you then realize that it hurt.
As I stated earlier the bone is a living organ and it too has nerves.
There is a nerve that enters the vertebrae in the center and sends branches to both endplates. Studies have shown that these nerve endings even proliferate in damaged and degenerated endplates resulting in more innervation than the discs. We had always assumed that when disc degenerates and collapses that it was the discs that caused the pain. We directed our treatment at fixing the discs only to discover that these treatments often did not work.
This lead to more study and investigations and the discovery that there is a nerve within the vertebrae that transmits pain signals. It is called the basivertebral nerve and this nerve has now been established as transmitting pain signals in some patients with chronic low back pain who have Modic changes to their vertebrae.
So how do we treat it? You will have to wait until next week to find out.