The term “collapsed disc” is something of a misnomer. To begin with, the word “collapsed” conjures images of an instantaneous loss of structural integrity. Aside from cases of traumatic spine injury, a so-called collapse does not happen suddenly with intervertebral discs. Rather, your discs tend to lose height, circumference, and mass over an extended period of time. This is true for a large segment of the population. In fact, gradual intervertebral disc degeneration is so common that it is considered by most medical professionals to be a normal part of the aging process. The available data back that up. By age 35, approximately 30 percent of people have experienced at least some disc deterioration, often at more than one level of the spine. By the age of 60, that number climbs to about 90 percent of the population. So, if you have begun to experience back or neck pain related to an abnormality within an intervertebral disc, you are far from alone.
Of course, that may not be of much comfort if your quality of life has begun to decline as a result of your condition. Intervertebral disc degeneration does not always produce symptoms, but when it does, they can become debilitating. Like the anatomical deterioration itself, symptoms tend to progress gradually, slowly robbing you of your ability to perform physical activities that you may once have taken for granted. As the symptoms worsen and your physical mobility decreases, you may also face emotional challenges. Debilitating back pain, whether related to a collapsed disc or some other spinal abnormality, can permeate every aspect of your life. Feelings of emotional distress can be compounded by the inability to work, or to enjoy favorite pastimes, or to spend pain-free quality time with family and friends.
Rather than allow yourself to sink into depression, there is another path – the path of education. The best way to combat the inevitable effects of the aging process on the intervertebral discs and other components of the spine is to learn as much as you can about conditions like a collapsed disc. The more you know about the spine’s anatomy, as well as the causes, risk factors, and symptoms associated with disc degeneration, the better equipped you will be to respond appropriately.
Anatomy
If a degenerating intervertebral disc does not, in fact, “collapse,” is there a better way to visualize what happens? Another term, degenerative disc disease, eliminates potential confusion about the immediacy of the condition, but it also is somewhat misleading; age-related disc deterioration is not actually a disease, per se.
It may help to think of it this way: A collapsed disc is, simply, a shrunken disc. In essence, that means the disc’s height and circumference no longer are what they were in a normal healthy state. Which, in turn, means that the disc no longer can serve as an effective cushion between its adjacent vertebrae.
Exactly why is it so important for discs to retain their height, flexibility, and cushioning power? To fully answer this question, it will help to clarify what an intervertebral disc is, what a vertebra is, and what one of their essential functions is – to protect the spinal cord and its nerve roots:
Vertebrae – The vertebrae make up the skeletal structure of the spine. These stacked bones start at the base of the neck and go all the way down to the tailbone. The typical spine has 24 individual vertebrae that span from the neck to the lower back, and several fused vertebrae in the pelvis. Each of the top 24 vertebrae has a round opening at its center, helping to form a long canal that provides a space to surround and protect the spinal cord.
Spinal cord – The spinal cord is a bundle of nerve fibers that begins at the base of the brain and ends in the lower back. The cord transmits motor and sensory messages, back and forth, from the brain to the body. As mentioned previously, the spinal cord is protected within a channel that’s created by the back part of the stacked vertebrae.
Nerve roots – From the top of the spine to the bottom, nerve roots branch off the spinal cord and exit the spinal column through spaces (foramina) between the vertebrae. Nerve roots are the starting point of the network of nerves that serves the entire body, carrying signals from the spinal cord to the rest of the body and back.
Intervertebral discs – The front parts of the individual vertebrae (except for the top two) are made up of vertebral bodies, which are flat, circular pieces of bone. One intervertebral disc is sandwiched in between each pair of vertebral bodies. The intervertebral discs are tough but relatively soft. Thanks to its vertebra-disc-vertebra-disc construction, the spine is able to bend, flex, and bounce back from a wide range of movements. The discs also help to keep vertebrae in their proper position – essentially holding them at a standard distance apart from each other so that the spaces in between vertebrae provide enough room for the nerve roots.
What happens to the spine when an intervertebral disc no longer can effectively cushion the adjacent vertebrae? This is the fundamental question regarding a collapsed disc, and an in-depth answer requires a basic understanding of the structure of the intervertebral disc. First, here is a basic description of a disc’s three main portions:
Nucleus pulposus – This is the gel-like center portion of an intervertebral disc, serving to distribute hydraulic pressure evenly when a disc moves. The nucleus is made up primarily of water and water-attracting proteins.
Annulus fibrosus – This is the outer wall of a disc, made up of layers of tough, flexible fibrocartilage.
Vertebral endplates – These cartilaginous layers serve to connect a disc to the vertebral bodies located above and below.
When healthy, these three components work together to keep the bony vertebral bodies from grinding together. When the spine is extended, the discs stretch accordingly, then return to their normal shape when the extension is done. Similarly, when the spine is compressed, healthy discs are able to absorb the pressure and again return to their normal shape when the movement is completed.
Now, think of all the movement your spine is subjected to every day. Every body position – sitting, standing, lying down, crawling, walking, running – involves the spine to some extent. Each of these movements places a different form of pressure on the intervertebral discs. The discs, when healthy, are flexible and tough enough to take the punishment, but only to a certain point. Eventually, all this wear and tear will begin to take a toll.
One way to visualize age-related deterioration within an intervertebral disc is to think about your favorite pullover sweater. It may be made of wool, fleece, cashmere, or some other warm, comfortable fabric. The neckline may be a V-neck, a turtleneck, or a crew neck. Chances are, as you’ve relied on that sweater to keep you warm year after year, the knit fabric has begun to lose its elasticity. Each time you’ve pulled it over your head, each time you’ve taken it off, the fibers of the fabric have stretched out a little more. The sweater begins to lose its shape. Meanwhile, each time you’ve put it through the wash cycle or sent it to the dry cleaner, the fibers have begun to lose their flexibility. This may be particularly pronounced around the collar, where the worn-out elastic may begin to fray. It just doesn’t snap back into place quite like it used to. Eventually, that old sweater can be consigned to the back of the closet or donated to a second-hand clothing store. Needless to say, there is no comparable option for a worn out intervertebral disc – we can’t store them away or trade them in – so we are often resigned to living with them while finding treatment to deal with the symptoms they cause.
Which leads us back to our fundamental question: What happens when an intervertebral disc shrinks? There are a number of potential consequences, some of which can cause real problems, some of which might never even be detected. This apparent contradiction is further explored below, in the section titled “Symptoms of a Collapsed Disc.”
The deterioration of an intervertebral disc often begins with the vertebral endplates, where the discs and vertebral bodies meet. Nutrients traveling from the bloodstream to the center of the disc are mostly diffused through the vertebral endplates, so the health of the endplates can play a role in the ability of the discs to stay nourished and hydrated. Furthermore, while the elastic nature of the disc’s outer wall allows for a great deal of disc flexibility, the endplates are fixed in place. This means the wide range of spinal movement places a great deal of strain on the immobile endplates, which can begin to calcify over time. This calcification is quite common, and even though it can contribute to reduced range of motion, it is not typically as troublesome as deterioration that occurs within the cartilaginous fibers of the disc wall, or annulus fibrosus.
Like the fibers within the collar of your favorite sweater, the fibers of the disc’s outer wall can begin to fray with repeated use. This fraying, coupled with a reduction in the water content of the nucleus pulposus, is what robs the disc of its height, circumference, and mass. The loss of height and reduction in mass, in turn, makes the discs work even harder to overcome the pressures placed on them by the adjacent vertebrae. And the harder the discs work, the faster and more thorough the deterioration.
The fraying of the outer wall and the additional pressure from within the nucleus can cause a portion of the annulus fibrosus to expand past its normal boundary. This is the condition known as a bulging disc. The disc may flatten a bit when a bulge happens, similar to how a balloon flattens and bulges out when you push on its center.
In addition, fissures or ruptures can begin to form within the outer wall, which may eventually allow a portion of the nucleus material to leak into the spinal canal. This is known as a herniated disc. As nucleus material escapes, the height of the disc may also be threatened, similar to how a toothpaste tube gets thinner as toothpaste is released.
Ruptures in the outer wall can form in a number of ways. The three most common types of outer wall tears are:
Circumferential clefts – Also known as delamination, this is a separation between the various layers of the annulus fibrosus.
Radial fissures – This type of tear occurs in a straight or nearly straight line running from the internal layers to the outer layers of the annulus fibrosus.
Peripheral rim lesions – This is the appearance of irregular rifts, typically within the exterior layers of the annulus fibrosus.
While the aging process is generally acknowledged as the primary cause of a collapsed disc, there are other potential causes and risk factors, which are explained in the next section.
Causes and Risk Factors
Although everyone can expect to experience a certain amount of deterioration within the intervertebral discs, the rate and severity of disc degeneration can vary widely from person to person. Why is that the case? Because people come in all shapes and sizes, with broadly different backgrounds, genetic make ups, and personal habits. Here is a breakdown of how these factors contribute to the rate of degeneration within the intervertebral discs:
Aging – Getting older affects everyone differently. The mere fact of aging does not necessarily mean someone will become less physically active. Some people are able to remain nearly as active in their 50s as they were in their 20s. Others may begin to slow down in their 30s. There is a demonstrable correlation between level of activity and the effects of the aging process. As we get older and our responsibilities with work, child-rearing, and maintaining a household increase, there is a natural tendency to reduce our commitment to exercise and fitness. Those who manage to maintain an active lifestyle despite those daily demands generally can count on staying strong and flexible as they get older. However, the aging process catches up to everyone, eventually, and even the fittest among us cannot prevent the discs from losing water content and height over time.
Obesity – Not surprisingly, extra body weight takes a serious toll on the components of the intervertebral discs. The discs within lumbar (lower back) region of the spine, in particular, are susceptible to weight-related wear and tear, because the lower back is extremely flexible and bears most of the weight of the upper body. Obesity can also inhibit the body’s circulation, which makes it more difficult for the discs and other components of the spine to receive vital nutrients.
Poor posture – Habitually slouching while seated or slumping your shoulders while standing can contribute to accelerated disc deterioration. Remember, a healthy disc “bounces back” into shape after extension or flexion of the spine. Keeping the discs extended or flexed for long periods can hinder their ability to regain their natural shape.
Repetitive stress – If your job or pastime requires heavy lifting or sustained periods of sitting, the discs are forced to work even harder. It stands to reason that, if the discs are subjected to repetitive movement or prolonged positions where they must keep the body upright and stationary, it can accelerate their deterioration.
Genetics – While the origins of certain degenerative spine conditions remain somewhat uncertain, genetics are believed to play a role. For example, if one of your parents or grandparents experienced problems with a collapsed disc, you may have a better chance of developing the condition.
Traumatic injury – Traumatic injury, as in a car accident, might also disrupt the spinal anatomy. Similarly, injuries sustained early in life – such as those incurred playing sports like football and gymnastics during the preteen or teenage years – can exacerbate disc issues later on.
Personal habits also can contribute to the acceleration of disc deterioration. Smoking causes circulation issues, and overeating can lead to obesity. A sedentary lifestyle also can contribute to obesity, as well as a weakening of muscles that provide important support to the spine and its intervertebral discs. If you are within one of these at-risk groups, talk to your doctor about ways to slow or mitigate the inevitable deterioration of your intervertebral discs.
Collapsed Disc Symptoms
What does it feel like when an intervertebral disc begins to lose height, circumference, and mass? At first, it may feel like … nothing. In most cases, the process is so gradual that you will not notice that your discs are not quite as flexible as they once were. Even if some symptoms are evident during the early stages of disc deterioration, they may be no more serious than a slight reduction in range of motion or a mild, occasional ache after strenuous activity. Chances are, you will simply chalk these symptoms up to getting older and get on with your daily routine.
Even as the discs become less and less flexible, there is no guarantee that you will notice much, if anything, out of the ordinary. The body is remarkably resilient and adaptable, and most people – especially those who have prioritized eating healthy and staying active – will be able to function without a problem. Yet, even if you are the biggest fitness buff in the neighborhood, you may one day find yourself experiencing disc-related symptoms that stop you in your tracks. These symptoms generally can be traced to two sources: pain that originates within the deteriorated disc itself, and pain that stems from nerve compression.
We have already learned that a collapsed disc is linked to two related conditions – bulging discs and herniated discs. Another potential consequence of a collapsed disc is the formation of osteophytes, or bone spurs, which are smooth growths of excess bone. Osteophytes, which also are commonly associated with spinal osteoarthritis, are the body’s response to a reduction in spinal stability. When a disc loses height and the bony vertebral bodies begin to scrape against each other, bone spurs can begin to grow.
How do these conditions produce symptoms? In the case of a disc herniation, the fissures or tears within the outer wall can be mildly painful, particularly if they damage or irritate the nerve fibers that innervate the outer one-third of the wall. The real trouble begins when the distorted outer wall of a bulging disc, or the extruded nucleus material from a herniated disc, comes into contact with the spinal cord or nearby nerve roots. In addition, bone spurs can grow along the sides of vertebrae and may begin to reduce the space available for the spinal cord and nerve roots. Finally, a disc that has collapsed will allow its adjacent vertebrae to move too close together, which can compress or “pinch” the nerve roots that are located in the tiny spaces (foramina) between the vertebrae.
Contact between these anatomical abnormalities and nerve tissue known as nerve compression, and it can produce the following:
Radiculopathy – This is pain, tingling, numbness, or muscle weakness in the extremities. It occurs when a nerve root becomes impinged, or pinched. Because discs in the lumbar region tend to deteriorate faster than in other parts of the spine, the lower back is particularly susceptible to nerve impingement. As it happens, the largest and longest nerve in the body – the sciatic nerve – originates in this area. Compression of the sciatic nerve produces a set of symptoms known as sciatica, which can affect the lower back, buttocks, legs, feet, and toes.
Myelopathy – This is weakness and body pain associated with compression of the spinal cord. A spinal cord impingement can seriously affect your gait, your reflexes, and bladder or bowel function. This can signal a serious medical problem, and you should seek immediate attention from your healthcare provider or the emergency room if you experience these symptoms.
Aside from the potentially serious problems associated with spinal cord compression, when should you consider seeing a doctor if you suspect you have a collapsed disc? There is no hard-and-fast rule, but generally, if you find that you are unable to perform routine tasks day to day, it is a good idea to seek a diagnosis from a medical professional. This is especially true if the symptoms become chronic (lasting three months or longer), or if the pain is so severe that you begin to miss work or other regular activities.
If you do visit a doctor to have your back pain diagnosed, come prepared to answer questions about the nature, severity, duration, and location of the symptoms. You may want to keep a journal of your symptoms, in which you also can record what kind of over-the-counter medicine you use to treat it. If possible, make note of your personal medical history, as well as that of your immediate family. All of this information is likely to come into play as your doctor seeks to make a diagnosis. In addition, you may undergo a physical exam and a neurological exam, in which range of motion, reflexes, and muscle strength may be measured. Medical imaging may also be ordered, potentially including an X-ray, an MRI, and/or a CT scan.
At AOMSI diagnostics, we have one of the few Vertebral Motion Analysis units in the United States. With this technology we are able to go beyond what an MRI and X-ray are able to identify and measure to a tenth of a millimeter your intervertebral disc height. With this level of specificity, your physician can have the most specific information to determine the best treatment for you.
Contact AOMSI diagnostics to set up your Vertebral Motion Analysis scan today.