Discography and discogenic pain

Abstract

Disc abnormalities, either directly or indirectly, are responsible for almost half the cases of back pain. A degenerated intervertebral disc without any impingement on adjacent nerve roots was suspected as a source of low-back pain in the 1920s. Discography is now considered a diagnostic procedure designed to determine whether a disc is intrinsically painful. The procedure involves inserting a needle into the nucleus pulposus and distending the disc with an injection of saline or contrast media. Postprocedure computed tomography can be used to highlight the features of internal disc disruption, which is the most commonly known cause of discogenic pain. The clinical history usually includes a deep, dull ache in the low back at the midline, with minimal radiation beyond the gluteal area and rarely to the knees and legs, no particular alleviating position, and pain that may worsen with axial loading. There is no accompanying sensory or motor loss. Provocative discography is widely used to identify the symptomatic intervertebral discs. Internal intervertebral disc derangement and positive provocation discography could be treated with surgical fusion or intradiscal electrothermal therapy. Application of heat to the intervertebral disc structure leads to thermal ablation of the nociceptors. Heat leads to contraction and shrinkage of collagen of the intervertebral disc and a decrease of the volume of the nucleus pulposus, resulting in a debulking of the intervertebral disc. Although intradiscal electrothermal therapy is a very promising procedure to treat discogenic pain, studies on its long-term effects, outcome measures, and cost-effectiveness are needed to validate the efficacy of this technique. Copyright © 2000 by W.B. Saunders Company