When we refer to disc bulge we are referring to what is known as disc protrusion. This consists of the bulging of the fibrous envelope that is responsible for surrounding the intervertebral disc. This differs from disc herniation in that the latter consists of an exit of part of the nucleus pulposus through a fissure that is located in the fibrous envelope of the disc..
Thus, we can talk about the difference between hernia and protrusion as the fact that there has been an exit of the content or only the deformation of the envelope without exit of content. It is in the latter case that we would speak of protrusion or disc bulge.
this is the theory, and it is that sometimes it is not easy to be able to see in an MRI if this has happened. For this reason, in some cases, Some doctors consider that if the deformation observed in the MRI has a base wider than that of the apex, it is considered a protrusion.; and in case the tip is as wide or more than the base, one would be talking about a hernia.
Index
How does a bulging disc occur?
Under normal conditions, disc wear undergoes a normal process that causes some of the fibers that are part of its fibrous envelope, go losing elasticity and resistance; and can also cause them to retract or split spontaneously. When this happens, part of its gelatinous content located in the disc can go outside and thus cause a disc bulge.
In some cases, the pressure suffered inside the disc can exceed the resistance capacity of the fibers of the fibrous envelope, so that part and a portion of the disc bulges or herniates. Since the nucleus pulposus is gelatinous in content, when the spine bends forward, the disc tends to see how it moves in the opposite direction, backward, so the same thing happens when it happens the other way around. The rear of the fibrous casing has less resistance than the front, since it is finer, hence it is more common for disc bulge to appear at the back of the disc.
In this way, the most common situation in which a herniated disc occurs is when the patient leans forward with their legs stretched out, when you carry weight in your arms and get up, increasing the pressure until the resistance capacity of the aforementioned fibrous envelope is exceeded and disc herniation occurs.
Nevertheless, this situation, Although it is the most typical, it is not the most frequent.; and it is that in most cases hernias are caused by a process of gradual wear of the fibrous envelope; and in few cases there is only one trigger of this problem.
There are different muscular mechanisms that reduce the pressure supported by the disc, and who work to prevent a disc bulge, since they stabilize the load.
Factors that increase the possibility of suffering a herniated or bulging disc
There are different factors that can increase the probability of a herniated or bulging disc, as they are, among others, the following:
- Having muscles that are too weak.
- Sitting for a long time, especially if it is a person who does not exercise, that is to say, be sedentary, as this accelerates muscle atrophy; or by adopting positions in which the anterior part of the vertebra bears a greater load than the posterior, for being bent over for many hours.
- Being subjected to vibrations that affect the body, which is common in people who drive tractors or other industrial machines; and it is that this can make it easier for a tear to occur in the fibers of the fibrous envelope.
- Other factors that can cause it are some genes, that may be linked to a lower resistance of the fibrous envelope.
Disc Bulging Symptoms
The interior or nucleus pulposus of the disc has substances that irritate the nerves. Under normal conditions there are no nerves inside the disc, so that these substances could not cause irritation of the nerves. There are usually nerves in the outermost part of said envelope and especially in the lateral parts of the posterior wall..
In the event that the hernia occurs in an area without nerves of the fibrous sheath and its volume is small so as not to compress the nerve root, may not cause discomfort or pain. However, in the event that it takes place in an area where there are nerves, the substances contained in the hernia will excite them and this will cause the following symptoms:
- back pain, in the lumbar or cervical area, depending on where the hernia occurred. This will be triggered by the rupture of the fibrous envelope and by the contracture that reflects the musculature.
- radiating pain, to the arm in the case of disc protrusions or bulging or cervical hernias, and in the case of the leg in the case of the lumbar. This pain is caused by the release of substances from the nerves that cause inflammation of the disc., the nerve root and the white tissues of the area, in addition to chemically irritating the nerve root. And if the volume of the protrusion or hernia is large enough or the inflammation important enough, it can also cause a compression of the nerve root. If sensory nerves are compressed, radiating pain will be experienced., that can occur together with an alteration or loss of sensitivity in the area whose sensitivity picks up that nerve. If a motor nerve is compressed, the strength of the muscle group innervated by that nerve is reduced.