Making sure back pain is coming from a disc problem can be difficult. Not all discs that cause pain show up on an MRI. There is one test that directly tests the disc but it’s expensive and painful. It’s called provocation discography.
This study looks at a noninvasive test for disc problems called centralization. Centralization is described as a change in the pain pattern. Back pain that goes into the buttock or down the leg becomes just back pain. The pain “retreats” or moves to the central part of the low back.
Researchers compared the centralization test to discography. They used the results to find out how reliable centralization is in predicting when the pain is coming from a disc. All patients were examined by a physical therapist and tested for centralization. Then they had a discography. Discography involves injecting a fluid into the disc. A positive discography is recorded when pain is caused by this test.
The results showed that centralization is a good test to predict disc problems if the patient is not in great distress. Psychosocial factors and severe disability are linked with unclear results of the centralization test.
The authors report that centralization is 100 percent accurate among patients who aren’t disabled or distressed. This means when centralization was present the discography was also positive, indicating a disc problem as the cause of pain.
Physical therapists can treat centralization successfully in patients without severe disability or distress. In these cases, patients may be able to bypass the painful provocative discography test.