Do Disk Herniations Cause Pain? The answer is maybe. There has been plenty of research on this topic, and while the exact mechanism of pain can still be debated, in general most agree the cause of pain, discomfort and radiations are secondary to three factors:
1. Chemical irritation. When a disk herniates, the soft inner component of the disk, called the nucleus will penetrate the outer wall of the disk ( the annulus) and allow certain components of the disk to spill out. These components include enzymes, cytokines, and other chemicals that have certain effects on the surrounding tissue. To make an analogy, the materials can cause a “chemical burn” effect on the tissues, causing the body to react by mobilizing an inflammatory reaction. These chemicals are currently being investigated in detail, hoping to find a quicker way to collect, or dilute or deactivate these reactions, therefore, potentially decreasing the pain and other effects caused by this “chemical burn”.
2. Direct nerve irritation of certain specific nerves. Located near the outer fibers of the annulus, are the so called sinu-vertebral nerves. Most spine researchers agree that these nerves have potential to generate pain when irritated. With disk herniations, the annular disrupts, and has potential to irritate this nerve. The pattern of pain is not always classic, but irritation of the nerve can lead to spine related pain and discomfort.
3. Mechanical pressure on the nerve sac, or the actual nerve. Who ever designed the spine did an wonderful job protecting the nerves and the spinal cord, while still allowing motion. The spinal cord, and the individual nerve fibers in the spinal canal is incased in the dural sac. To make an analogy, the dural sac is like a garden hose, and within the water filled hose, are individual nerves or the spinal cord, floating within that cord. Normally there is room within the dural sac, so that stretching, bending, and some compression of the sac will not cause direct compression on the spinal cord, or the individual nerve. But sometimes, the stretch, or compression is significant enough to cause irritation onto these individual nerves, or the spinal cord itself. As stated above, the fluid filled dural sac usually has enough space to allow movement for the individual nerves or cord within the sac. But, significant disk herniations, fractures, or other causes of significant compression can cause actual entrapment of the nerves or the cord.
By these three mechanisms, we can usually explain the rationale for treatments prescribed for symptomatic disk herniations.
1. NSAIDS, ESI’s and steriod medications are designed to decrease the inflammation caused by the “chemical irritation”.
2. Narcotic medications can also dull the pain associated with the irritation of the nerves, or inflammation of the tissues.
3. Physical therapy can relax the inflammed muscles, and strengthen the core muscles, preventing further pressure on the annular disruptions.
4. Activities modifications can also protect further inflammation, or prevent further annular disruptions.
5. By decrease the pain, the patient can give the body time to decrease the inflammation, eliminate the chemicals, and allow the herniated fragment to dehydrate and shrink away from the cord or the nerve.
6. If, however, the pain is too severe, or if there is further development of weakness, surgery can be a reasonable and effective alternative.
- Jensen OK, Nielsen CV, Sørensen JS, Stengaard-Pedersen K. Back pain was less explained than leg pain: a cross-sectional study using magnetic resonance imaging in low back pain patients with and without radiculopathy. BMC Musculoskelet Disord. 2015 Dec 3;16:374. PubMed PMID: 26635015