Discography is one of the diagnostic tools doctors use to get to the root of spinal pain.
About the Discs
Normal discs in the spine have nerves in the annulus fibrosis (outer tissue layers). Injury to the discs can tear the annulus. Patients typically will experience pain while the disc is healing and new nerve endings are forming. Discs in the vertebrae also contain a nucleus pulposus in the center, which has water that allows for weight bearing. This can leak after injury, and the contents can get into the outer layers or even the nerve roots that are leaving from the lower part of the spinal cord (cauda equina). These leaking chemicals are irritating to nerves and can make them more sensitive. This causes pain as well, and disc degeneration may also occur. As discs lose water, when we age, degeneration is normal; however, when it is severe, patients experience pain (i.e., leg pain, neck pain, back pain) as the spine puts pressure on nerve roots or facet joints.1
What is Discography?
Patients present with back, neck, or leg pain to their care provider, and their doctor needs to perform diagnostic tests to find out if the disc is the cause of the problem. MRI is one diagnostic tool, and it can show abnormalities in the discs, but it cannot demonstrate if those are causing the pain. Sometimes discabnormalities don’t cause pain. The discography procedure is meant to determine if the abnormalities are causing the pain. Needles are inserted into the disc, which makes discography an “invasive procedure”. Discography is generally used in patients who have not had relief from many months of conservative treatments (i.e., activity modification, physical therapy, medication). The results of the procedures can lead to new treatments, or even surgery, for the patients. Patients prepare for the discography with solid food restrictions the night before. Medical history (such as current pregnancy, diabetes, or epilepsy) and allergies (such as to xylocaine or X-ray dye) are discussed beforehand. Patients are lightly sedated and are put on their side during the discography so that the doctors can access the “lowest two or three lumbar disc levels” and contrast material is injected. If that material exits the center of the disc, the disc is considered torn and abnormal. Patients rate the amount of pain they experience, and they are asked if the injection pain is similar to normal pain locations for their usual symptoms. CT scanning can happen after the injection. Patients may also receive antibiotics.2
There are some issues with discography. Discography (discogram) is typically used to determine if surgical interventions are needed, but the spine professional needs to be careful about false positives. The procedure should only be done in patients who have experienced long-term pain and no relief from less-invasive interventions. Patients need to let the doctor know about all allergies, and they cannot be on blood thinners or pain medications around the time of the procedure.3 Complications, such as discitis (infection), urticaria (skin vascular reaction), nerve root injury, bleeding, headache, increased pain, and more, can result. Some doctors have found “conflicting data on the benefits of discography”, while others find it helpful to determine the root causes of the pain.4 The number of false positives from discography could lead to unnecessary surgery. Patients need to be properly selected for this procedure, both physically and psychologically.5