| Discography is part art and part science. It is the placement of needles into the spine with injection of contrast agent for the purposes of 1. determining if there is a specific or more than one painful discs 2. determining the presence of annular tears for further minimally invasive spine procedures 3. determining whether a planned fusion surgery or artificial disc replacement would potentially benefit the patient 4. providing validation for the presence of pain generators in the spine. Many people have annular tears which do not produce pain, therefore discography is the only functional test of the tendency of a specific disc to produce back and/or leg pain. The sequence is as follows: sedation, placement of needles into the center of the intervertebral discs, awakening, conversing, injecting the disc with a controlled graded pressure with fluoroscopic evaluation and with the patient giving feedback on the degree, character, and location of pain produced in each disc, and subsequent CT scanning when necessary. Discography can be performed at any level of the spine including the thoracic and cervical spine, but the most commonly injected discs are those of the lumbar spine. It is absolutely necessary to have a control disc (one which does not produce significant pain at reasonably high pressures) in order to have a valid discogram. Also, the person's response to the injection (calm, clear answers vs. unresponsiveness or refusal to answer questions) is as important as the injection itself. Clearly, the pain reproduced during the injections is more valuable an indicator of pathology which may be causing the normal everyday pain than presence of annular tears on fluoroscopy. In fact, if the pattern is grossly abnormal on fluoroscopic exam but the patient has no pain, then the annular tear is probably not producing the pain. Additionally, not only the presence of pain but the pressure at which it is produced gives significant information regarding the degree of disc pathology. Cervical discography has special considerations which require two injections into the discs on different occasions. The first is used to isolate the most painful discs and the second is to anesthetize the inside of the suspected disc with a local anesthetic and observe for post injection pain response over the ensuing several hours. After the discogram, the patient may be taken to CT for further analysis of the disc as seen in the last picture. Side effects are usually pain for 1-7 days which may be somewhat increased, a fullness in the spine, and muscle soreness. Complications are uncommon but include in the lumbar area bleeding, infection, nerve injury, infection of the disc, worsening pain, reaction to medications used, anesthetic risks. In addition to the above, cervical discography complications also include penetration of the esophagus, carotid artery, jugular vein, or cord injury although all these are exceedingly rare. |
|||||
| Click on pics below to enlarge |
|||||
| Discography |
