Discography

Dimitris Papadopoulos MD Fellow Of Interventional Pain Practice (FIPP)

Updated 16 January, 2011

GENERAL

Discography is a minimally invasive technique used to show to which extent one or more intervertebral discs are the origin of chronic pain in low back or neck pain. Although the MRI can reveal  intervertebral disc degeneration,  it is just an image representation and cannot prove that the degenerated disc is the actual origin of pain.

Provocative discography is applied in chronic low back pain or neck pain after having excluded other potential causes of pain, such as facet joint syndrome, sacroiliac joint dysfunction and radicular pain.



TECHNIQUE

Discography is applied under fluoroscopic guidance with patient lying in the prone position. The patient remains awake and in close cooperation with the physician performing the procedure. As soon as the skin is carefully sterilised and local anaesthesia is provided at the injection site, a special needle is advanced into the nucleus of the intervertebral disc in question without the patient knowing which this is. Contrast medium is injected with a special device ( connected with the needle) measuring the volume of the contrast solution and intradiscal pressure, while all measurement data are being recorded in detail. If pressure within the disc increases and at the same time the patient reports pain of sufficient intensity similar to the pain he has been suffering from (>7/11), then probably the specific disc is the origin of pain. In order to confirm this finding, follows discography of two more discs of reference for comparison with a potential healthy disc which causes no pain and presents normal pressures and contrast medium diffusion within the nucleus.
The interventional examination lasts from about 30 minutes to 1 hour. Then, a CT scan follows revealing the exact distribution and diffusion of contrast medium into the intervertebral disc. Based on the latest examination, the intradiscal degeneration is classified according to the Dallas scale.

DALLAS SCALE

Degree  0 = contrast medium remains within the nucleus (normal disc)
Degree 1 = annulus fibrosus has microruptures and contrast medium diffuses up to the inner third of annulus fibrosus
Degree 2 = annulus fibrosus presents moderate degeneration and contrast medium diffuses through ruptures up to the middle third of annulus fibrosus
Degree 3 = annulus fibrous presents significant degeneration and contrast medium diffuses through ruptures up to the outer third of annulus fibrosus
Degree 4 = annulus fibrosus presents  severe degeneration, contrast medium diffuses through ruptures up to the outer third of annulus fibrosus and  covers its greater part in a circular direction

ABSOLUTE DISCOGENIC PAIN

•    Increase of pressure on the target disc causes identical pain
•    Severity of pain is scored by the patient at least with score number 7 in the 10-grade scale (>7/10)
•    Pain is reproduced with pressure below 15 psi  above starting-point pressure.
•    Increase of pressure to two more adjacent discs does not cause pain 

HIGH PROBABILITY OF DISCOGENIC PAIN

•    Increase of pressure on the target disc causes identical pain
•    Severity of pain is scored by the patient at least with 7 in the 10-grade scale (>7/10)

•    Pain is reproduced with pressure below 15 psi  above starting-point pressure.
•    Increase of pressure to one more adjacent disc does not cause pain

DISCOGENIC PAIN

•    Increase of pressure on the target disc causes identical pain
•    Severity of pain is scored by the patient at least with score number 7 in the 10-grade scale (>7/10)
•    Pain is reproduced with pressure below 50 psi  above starting-point pressure.
•    Increase of pressure to two more adjacent discs does not cause pain 

PROBABLE DISCOGENIC PAIN

•    Increase of pressure on the target disc causes identical pain
•    Severity of pain is scored by the patient at least with score number 7 in the 10-grade scale (>7/10)
•    Pain is reproduced with pressure below 50 psi  above starting pressure.
•    Increase of pressure to one more adjacent disc does not cause pain and increase of pressure on one more disc, over 50psi above the starting pressure, causes pain similar to daily pain.

CONTRA-INDICATIONS

•    Absence of written consent
•    Local infection
•    Gestation
•    Systemic infection
•    Patient taking anticoagulants (discontinuation and regulation is recommended )

RISKS – COMPLICATIONS

As happens with all drugs and interventional techniques, there is always the risk of provoking some complication. In general, discography is considered to be a procedure of low risk with very few complications. Although discitis is rare as a complication, it can be very serious when occurring. Discitis is an infection of the intervertebral disc manifested with intense pain within a few days following discography and is due to some bacterium that has intruded the disc. Other complications are haemorrhage, haematoma, headache and aggravation of pain.
In order to reduce the chance of provoking discitis, antibiotic medication is provided intravenously 30 minutes before the operation, as well as intradiscally before the absorption of the needle by the disc.

RESULT OF DISCOGRAPHY

As soon as the result of discography is evaluated by the therapist physician, the therapeutic options are discussed with the aim of eliminating or reducing pain and improving the patient’s functional ability and quality of life.

MEDICAL INFORMATION SOURCES

1. PAIN PRACTICE JOURNAL

2. BONICA”S MANAGEMENT OF PAIN

3. PAIN PHYSICIAN JOURNAL

4. INTERVENTIONAL PAIN MANAGEMENT BOOK

JOURNAL ARTICLES

Evocative lumbar discography Montes García C, Nava Granados LF. Acta Ortop Mex. 2007 Mar-Apr;21(2):85 PMID: 17695763 Discography: over 50 years of controversy Wichman HJ. WMJ. 2007 Feb;106(1):27 PMID: 17393754 Systematic review of discography as a diagnostic test for spinal pain: an update Buenaventura RM, Shah RV, Patel V, Benyamin R, Singh V. Pain Physician. 2007 Jan;10(1):147- PMID: 17256028 www.spine.org