Cystometry:

Cystometry refers to testing of bladder function.  Cystometry can be used to evaluate urge incontinence in the patient with suspected spinal cord dysfunction.  Carefully performed cystometry can provide valuable information about detrusor muscle function.  Cystometry can help to evaluate:

1.                  Bladder wall sensation.

2.                  Motility of the bladder.

3.                  Sphincter integrity.

4.                  Response to feeling pressure.

5.                  Neurological responses.

Discography:

Discography is a provocative test used to help identify whether a specific intervertebral disc is contributing to spine or back pain.  The discogram is not performed to treat pain.  Standard diagnostic imaging tests such as plain X-rays, CT, MRI and myelography are not always helpful localizing the primary source of back pain.  These scans are primarily limited to evaluating tissue structure (anatomy) and therefore cannot be used to confirm the precise source of spine pain.  Pain primarily arising from an intervertebral disc is referred to as discogenic pain.  Discogenic pain may refer to the neck, mid-back, low back, chest, abdomen or extremities.  Discogenic pain is often associated with disc degeneration and/or herniation. 

Discography is sometimes performed to address whether a patient is a candidate for an interventional procedure or surgical fusion at the site of the involved disc.  A negative discogram may help prevent a surgical procedure which would not likely help reduce pain.

During the discogram procedure, an IV is used to administer antibiotics and medication to help the patient relax.  The attending physician numbs the skin and then carefully inserts a needle into the center of the intervertebral  disc guided by X-ray (fluoroscopy).  After the needle is properly positioned, a small amount of contrast (radiographically opaque dye) is administered into the center of the disc.  This causes and increase of pressure within the disc.  If the injected dye reproduces the patient’s primary complaints, it is felt that the discography findings are concordant (correlates with) the patient’s pain and thus the symptomatic disc has been identified.  If the pain is not like the patient’s primary complaints, the reproduced pain is considered discordant (not related) to the primary painful complaints.  Provocative discograms are typically done at several disc levels to ensure the level of involvement is well defined.

After a discogram is performed, a thin slice CT scan may be ordered to evaluate the structural integrity on the intervertebral disc.  The radio-opaque dye that was injected helps to define the anatomical borders within the center of the disc.  Symptomatic discs are often internally deranged (they have internal discontinuities, which may or may not, extend to the outer borders of the disc and result in a frank herniation).  There are many risks associated with a discogram, which include but are not limited to infection, nerve damage and chronic pain.