WHAT IS A DISC BULGE?
To really understand what a bulging disc is, I will discuss the classifications to describe the disc lesions because there are a variety of terms commonly used like disc prolapse, slipped disc, ruptured disc and disc herniation.
Another term people often hear is called Disc Dessication. Disc Dessication is when annular fibers degenerate due to dehydration. One preventative step is to drink as much water as you can if you feel that you have or are developing a disc herniation.
The term disc herniation implies that a rupture or a tear of the annular fibers (annulus fibrosus) occurs allowing movement of nuclear material (nucleus pulposus) to escape beyond the verterbral (spinal bone) margins. The nuclear material may protrude out and cause a stretching of the annulus fibrosus or rupture through the annulus.
There are four classifications to describe disc lesions:
1. Annular bulge--also known as a disc bulge which is a small disc herniation that does not directly contact the nerve root and left untreated can easily progress to a larger degree of nuclear protrusion because of loss of annular fibers that hold the nucleus pulposus in place. Degeneration will predispose annular fibers to fail following trauma.
2. Disc Protrusion (herniation)--represents a rupture of the nucleus pulposus through a defect in the annular fibrosus, producing leaking of the disc. Intervertebral (between the spinal bones) disc herniations result in some degree of central spinal canal or foraminal (opening between vertebrae where the nerves exit) occlusion (blockage).
3. Disc Extrusion--occurs when a portion of the nucleus pulposus fibrocartilage and end plate bone cartilage have pushed and moved through outer annular fibers. Disc extrusions may compress the root, cord or both and cause shooting pain.
4. Free disc fragment (Sequestered Disc)--refers to the extra-annular separation and migration of a piece of nuclear material. Pieces of the nucleus pulposus escape the annulus fibrosus fibers and float into the spinal canal. Cauda Equina Syndrome can be a common phenomena of this. This is when you lose control of bowel and bladder function. This is an emergency situation and usually requires surgery to correct the problem.
The most common area for disc problems is at the lower lumbar vertebrae, L5. The pressure causes the jelly material (nucleus pulposus) insided the disc to "bulge" or "slip" out of place. This nuclear bulge itself puts pressure on the nerves (usually the spinal nerve). The spinal nerve is very sensitive and even a small amount of pressure causes the nerve to malfunction. The most common cervical disc to herniate is the fifth, known as C5, and causes cervicobrachial syndrome or symptoms like carpal tunnel syndrome or weakness in the arms or a burning or stinging sensation in the arms.