Benoist, M. (2002). The natural history of lumbar disc herniation and radiculopathy. Joint Bone Spine, 69(2), 155-160.

BACKGROUND

A herniated nucleus pulposus (also called HNP or herniated lumbar disc) can cause serious back pain as well as pain that radiates down the lower extremity. For many years, surgery has been considered a primary treatment for the HNP; however, that view has changed dramatically in the last decade or so. Conservative treatment is now used more frequently for addressing back and leg pain from an HNP. One of the main reasons that surgery is used less frequently is that the surgical procedures used for treatment of back pain did not have a very high success rate, and many patients had long term problems that appeared to have resulted from the surgical intervention.

In recent years, clinicians have demonstrated success with various conservative treatments. This success calls into question what produces most of the pain in cases of HNP, and why conservative treatment may be able to yield positive results in many cases.

The authors of this study indicate that our understanding of what occurs during HNP is very unclear, and this may be one of the reasons we don’t fully comprehend what occurs during the rehabilitation process. In their article, they review a number of studies that may help shed some light on the natural course of lumbar disc herniation -- in essence, what happens to the disc once it herniates.

DISCUSSION

One of the most significant factors that occurs with many conditions involving a HNP, is that many people have a resolution of symptoms within several months even if they do not undergo any treatment at all. For many others, the non-surgical treatment will speed up that process of resolving their primary complaints. Prior to the advent of CT scanning and MRI technology, our ability to determine what has happened to discs after the initial herniation was very limited. However, now that we have this technology, we can look at disc protrusions once the symptoms have subsided and gather more information about what has occurred.

What is interesting to note is that in repeated investigations, clinicians found that herniated discs can, and often do, recede from the region where they would put pressure on a nerve root. What was even more surprising is that the greatest amount of disc resorption occurred with the largest herniations. Small herniations and protrusions showed little or no change in many cases. In addition, they found that there appears to be a group of patients who have reductions in symptoms but no change in size of the disc herniation, which calls into question the cause of radicular (nerve root) pain.

There appear to be several explanations for how the disc may return to normal size over time, including dehydration and shrinkage of the HNP, further movement of the nucleus into tears in the annulus, or separation of various fragments of the HNP that are eventually resorbed and no longer press on nerve roots. However, our understanding of these processes is still incomplete.

The ramifications of this finding for the clinician are serious when attempting to evaluate the effectiveness of various treatments for HNP. For example, if a large percentage of people are going to have a reduction in symptoms as a result of disk shrinkage and not from our particular treatment intervention, we must consider that as a reason the condition has improved. Also, this would encourage us to think about what types of treatment options might be helpful to encourage the disk shrinkage/migration in order to improve treatments even further.

Back to Article Index