Discography

 

Discography is currently used to determine whether the disk is the source of pain in patients with predominantly axial back or neck pain. During discography, contrast medium is injected into the disk and the patient's response to the injection is noted; provocation of pain that is similar to the patient's existing back or neck pain suggests that the disk might the source of the pain. Computed tomography (CT) is usually performed after discography to assess anatomical changes in the disk and to demonstrate intradiscal clefts and radial tears.

Injection of the center of intervertebral discs of the spine is a standard pain management diagnostic technique.  It represents the only functional way information about the disc can be obtained.  When sitting or standing, the pressures in the disc rise markedly.  MRI evaluation of the disc is performed with the disc at low pressure, and does not reproduce the anatomy or pathology of the discs in the sitting or standing positions which have far more pain production in most patients with disc disease.  Therefore, MRI misreads both the anatomy and pathology of the discs.  Discography determines not only which discs are pain producing, but determines the presence of tears in the annulus or disc herniations which are missed on MRI.  By combining the injection with a manometer, the technique becomes more accurate (provocative manometric discography).

Placement of a series of needles into the center of the disc is performed under sedation anesthesia, followed by awakening, then pressure injecting.  The normal everyday pain pattern is attempted to be reproduced during the injections.  If a disc is painful at low pressures and has characteristics on x-ray of a torn disc or herniated disc, a CT scan of the contrast containing disc is performed to exactly identify the location of the tears.  Therapy can consist of IDET, nucleoplasty, SED, or fusion.  Because the annulus requires a very long time to heal, these tears can exist for years before their discovery through discography.   

Discography should be performed only if adequate attempts at conservative therapy and noninvasive diagnostic tests, such as MRI, have failed to reveal the etiology of back pain.

Specific indications for discography include the following:

 

• Persistent, severe symptoms when other diagnostic tests have failed to clearly confirm a suspected disk as a source of the pain

   

• Evaluation of abnormal disks or recurrent pain from a previously operated disk or lateral disk herniation

   

• Assessment of patients in whom surgery has failed, to determine whether pseudoarthrosis or a symptomatic disk in a posteriorly viewed segment could be the source of pain

   

• Assessment of disks prior to fusion to determine whether the disks of the proposed fusion segment are symptomatic and whether the disks adjacent to this segment can support a fusion

   

• Assessment of candidates for minimally invasive surgery who have a confirmed disk herniation

Complications associated with discography include spinal headache, meningitis, discitis, intrathecal hemorrhage, arachnoiditis, severe reaction to accidental intradural injection, damage to the disk, urticaria, retroperitoneal hemorrhage, nausea (2%), seizures (4%), headache (10%), and increased pain (81%).