Chapter 31: Provocative Discogram

INTRODUCTION

Discography has been practiced by interventional pain physicians for the last few decades in an attempt to identify the pain generator in the lumbar or the cervical spine (and less commonly the thoracic spine). Although this procedure was initially intended to identify a pain generator that can be surgically treated with a fusion, it was eventually utilized to diagnose a contained disc herniation as well as internal disc disruption. Evolution of intradiscal procedures such as IntraDiscal Electrothermal Treatment (IDET), percutaneous disc decompression, cooled radiofrequency use for biacuplasty, etc, have led pain physicians to perform these procedures as minimally invasive treatment options for disc pathology.

In a lumbar disc, the intradiscal pressure increases based on the spine position. While the pressure is at the baseline while lying down, it does increase somewhat when standing. However, sitting can increase the pressure to almost twice as much, as the lumbar spine flexes and the relaxed muscles do not contribute as much in weight bearing. Bending forward while sitting can increase the pressure to almost 3 times and adding a twisting movement can increase it to 4 times as much as standing. A patient complaining of pain in the lower back while performing any of these activities, and does not have any obvious cause for the back pain is a good candidate for this procedure.

Indications

• Provocation discography is performed to identify a disc that is likely source of pain.

• Other diagnostic tests have failed to clearly confirm a suspected disc as a source of persistent pain.

• Assessment of discs prior proposed fusion of segment with symptomatic discs, and whether the discs adjacent to this segment can support a fusion.

• Assessment of candidates for minimally invasive surgery who have confirmed disc herniation.

• Evaluation of abnormal discs or recurrent pain from a previously operated disc.

• Assessment of patients in whom surgery has failed, to determine whether pseudoarthrosis or a symptomatic disc to be the source of pain.

DIAGNOSTIC PROVOCATIVE DISCOGRAPHY

Purpose

The purpose is to simulate disc loading in a lumbar disc that happens with forward flexion and increased intradiscal pressure. This may be reported by a patient as sitting intolerance, aggravation of back pain while bending forward, etc. Provocative discography is the procedure performed to reproduce discogenic pain by injecting contrast in the disc. The pain is reproduced either by chemical irritation of sensitive tissue, or by increasing the intradiscal pressure due to volume and stretching the annular fibers of the disc. Discography helps to evaluate disc morphology and confirms the diagnosis for consideration of surgical intervention. It also helps to identify the normal discs.

• Diagnostic purpose to identify the pain generator for back pain which is mechanical and axial in origin and neck pain which is axial and no other pain generator can be identified.

• Identify the ...