Degeneration of the neck

The focus of this discussion is better understanding of degenerative disorders of the cervical spine. These affect adult patients of any age, with a tendency for particular disorders to affect certain age groups. Cervical disk herniations are more characteristic in the young (less than forty-years old), while cervical spondylosis (spon-dee-low-sis) and stenosis (sten-oh-sis) are typically found in older patients. Treatments vary from observation, medications, and therapy to injections or operative intervention. Treatment depends on the severity of the condition as well as the expertise of the doctor.

Definition: Degenerative Disease

As a patient, the first question is obvious. "What is degenerative disease of the spine?" In all honesty, the academic leaders of the spine world are currently pondering this same question. What we mean is that spine doctors can recognize and treat degenerative disorders of the spine but are often unclear how the disorder actually arises except to attribute it to age. To date, most theories about how the spine degenerates remain just that-theories. Although these theories are often well thought out and reasonable, it is exceedingly difficult to prove them. Regardless, it is worthwhile trying to understand them, as they are the best explanation we have to explain degenerative disease of the spine at this time.

Range of motion

Degenerative disease of the spine refers to a breakdown of the normal architecture of the various components of the cervical spine. Normally, the neck is very flexible. As you may demonstrate on yourself, the neck allows the head to rotate from side to side nearly 180 degrees, to flex forward to touch your chin to your chest, and extend backwards to almost touch the back of the head to your upper back, as well as bend your head toward your shoulder (and all ranges in between these basic motions). These motions are afforded by the various joints of the cervical spine. If you do not have these normal ranges of motion, you should see Dr. Cady for an evaluation.

Anatomy

There are seven cervical bones in the spine. Known as vertebrae (ver-ta-bray), they can be likened to the cars of a passenger train. The cars of the train, by themselves, are stiff with no ability to bend. Each car (i.e. vertebra) is joined to its neighbor by a joint. The joint allows motion between the cars. As in the spine, joining a number of cars together can allow overall motion. The more joints and vertebrae (the plural of vertebra), the more motion is allowed. In contrast to the joints of the car, the cervical vertebrae are connected by three joints. This gives the spine more stability, while still allowing motion. The extremes of motion must be limited because of the fragile "freight" that the vertebrae hold-the spinal cord. Like the people in the cars of the train, the spinal cord is located in the center of the vertebrae.

At this point, clarification of terms is important. "Spine" refers to the bony parts. These are the vertebrae that were described above. "Spinal cord" is the nerve elements that travel within the spine from the brain down to the rest of the body. The spinal cord transmits signals (bioelectrical and biochemical) that control all the functions (muscles and sensation) below that level. The function of the spine is to protect the spinal cord from injury during motion and activity.

Joints are comprised of two opposing surfaces of bone. Some joints are covered with smooth, glistening cartilage. The slippery properties of cartilage (car-til-ledge) make the two surfaces move easily in relation to each other. The facet joints of the cervical spine have these properties.

In contrast, the main joint between two cervical vertebrae is made up by a large spongy mass, the intervertebral disc. This disc sits between the two broad flat surfaces of the vertebral bodies. The disc is made up of specialized materials that act as a soft "glue" between the bones, while still allowing them to move. The disc is extremely important to spinal stability. However, it is a frequent site of degeneration or breakdown.

In another way the disc can be considered as a pillow in between two bones. The pillows can softly resist the downward forces placed on the vertebrae from the weight and movement of the head. A good pillow is thick and soft and functions best. It allows some movement between the vertebrae. Because the pillow is well fixed to both bones, it resists the tendency of the bones to become misaligned. With time and use the pillow can become flattened.

In this state the disc no longer provides adequate cushioning between the vertebrae. The bones then come closer and closer together. Because the disc is no longer sustaining the forces that it usually does, the other joints of the spine are forced to take on these extra loads. The two smaller sliding joints (facet joints, fah-set) have greater demands placed on them.

Since they were designed to sustain only a small portion of the forces of the spine, the previously glistening, healthy cartilage starts to breakdown. As the cartilage degenerates, the underlying bone becomes exposed and an inflammatory reaction begins. This causes irritation of the joint, which can lead to pain. This sets up a vicious cycle of events. The more the facet joints become degenerated, the less they are able to tolerate the increased demands. Thus, greater demands will then be placed on the intervertebral disc, causing it to further degenerate (or breakdown) as well. The changes in the intervertebral disc and facet joints are not reversible at this time.

Common Disorders

Cervical Stenosis

An important feature of disc degeneration is the reaction that the bone undergoes. Because the normal relationships of the bones are lost, there is a condition of instability. This refers to one vertebra moving in an abnormal manner in relation to the next vertebra. To attempt to stabilize this excess motion, bone grows outward. These outward growths are called osteophytes (os-t-o-fights). Osteophytes can be found near the disc spaces and around the facet joints. Osteophytes take up space. If they grow in areas where nerves or the spinal cord are nearby, they can impinge or compress these structures. This can cause pain, numbness, tingling, or weakness to varying degrees. If significant enough to cause nerve dysfunction, it is known as cervical stenosis.

Cervical Disc Herniation

Disc degeneration can sometimes follow a slightly different course. In the process of sustaining increased mechanical loads, the outer aspect of the disc, known as the annulus (an-you-lus), can become stressed. With time, small tears can form in the anulus. This outer ring normally keeps the soft, gel-like center of the disc contained. The gel center, known as the nucleus, can be ejected from the disc through an annular tear. This is called a disc herniation (her-knee-aye-shun). If the disc herniates in the direction of the spinal cord or nerve root, it can cause neurological compromise. Disc herniations in the cervical spine can be serious. If significant enough, they can cause paralysis of both the upper and lower extremities, though this is extremely rare.

In most cases, a patient complains of neck pain associated with radiating pain to one arm. This is caused by compression of a nerve root, rather than the spinal cord itself. With time some herniated discs resolve or shrink by themselves. Sometimes, disc herniations can persist, causing prolonged symptoms and neurological problems, which may lead to surgical considerations.

Subluxation Degeneration

Understanding the ongoing process of subluxation, and the effect time plays on the subluxated spine.

Subluxation

This is a representation of one type of subluxation. A subluxation, as defined by the Association of Chiropractic Colleges is: "A subluxation is a complex of functional and/or structural and/or pathological articular changes that compromise neural integrity and may influence organ system function and general health." When a subluxation is present, it causes nerve interference in some portion of the body affected by those nerves. The subluxation causes changes to the structure as well as the nerves. These changes get progressively worse as time is allowed to work on the subluxated area of the spine. These changes take the form of ongoing degeneration known as "subluxation degeneration". By understanding the type and amount of changes, it is possible to reasonably estimate the time subluxations have been present in a spine. Having this information is useful in understanding the time and effort needed for correction.

Near Normal

This is a side x-ray view of the neck. As with all the pictures you will see on this page, the patient is looking to the right of the screen, so you are viewing the right side of their neck. We will call this picture a "near normal" spine. Compare this spine with the ones you will see below on this page. Notice the normal forward curve of the neck. This curve helps absorb shock. Notice how each of the disc spaces between C2 (second bone in neck) and C7 are thick and even, this again is normal. Also notice how the front portions (right on the x-ray) of each of the vertebrae (called the 'body' of the vertebrae) are fairly square with clear and well defined borders. This type of arrangement is normal in the neck. Normal vertebrae in other parts of the spine also have similar characteristics to what we see here. When subluxations occur and are left uncorrected, ongoing relentless changes occur that result in damage to the structure and function of the spine along with nerve damage and the resulting problems caused from improper nerve supply.

Phase One Subluxation Degeneration

Phase One Subluxation Degeneration is seen in subluxations that have been present for up to twenty years. This phase is characterized with a loss or change in the normal curve in the spine. On this example you can see that the normal forward (lordotic) curve is lost. This spine even has developed a reverse curve in the neck. The disc spaces have also begun to exhibit a slight change in shape. One good point is that the bodies of each of the vertebrae (the square part in front) still exhibits clean clear borders. Segmental motion may be abnormal but overall motion is probably not affected. Chiropractic reconstructive care for a phase one can take from 6 to 18 months. More than 80% of people with Phase One Subluxation Degeneration have no pain. Therefore, if left uncorrected, phase one continues to progress with time until it eventually reaches the next phase.

Phase Two Subluxation Degeneration

Phase two subluxation degeneration is normally seen in subluxations that have been present between 20 and 40 years. This phase has some of the same characteristics of the previous phase including a loss of normal curvature and position as well as an alteration in segmental motion. In addition, spines with Phase Two Subluxation Degeneration many times show a reduction in the patient's range of motion in that area. X-rays of a phase two begin to show calcium changes or buildup at certain levels of the spine. These changes are sometimes called by many names including spurs and arthritis. Disc spaces between the affected vertebrae are noticeably narrower and may appear to be flattening out. Although most people with Phase Two Subluxation Degeneration may not exhibit any symptoms, some may start to feel stiff or achy. Chiropractic reconstructive care for patients in phase two ranges from 1.5 years to 2.5 years. Again, if Phase Two Subluxation Degeneration is left uncorrected it slowly advances to the next phase.

Phase Three Subluxation Degeneration

Phase Three Subluxation Degeneration is caused by subluxations that have been continuing on for between 40 and 65 years. This phase has all of the attributes of the previous phases, only worse. The curvatures are abnormal. The disc spaces are vastly decreased and changed. Calcium changes on the spine are abundant in this phase. Normally, people in phase three have a restricted range of motion and probably exhibit symptoms of some kind. In phase three the vertebrae show obvious changes and mutations in shape. Projections made of calcium, sometimes referred to as "spurs or lipping", can be readily seen on x-ray. Chiropractic reconstructive care for patients in phase three ranges from 2.5 years to 3.5 years. This does not mean that at the end of this time that any or all of the calcium changes will be gone. In many instances the body adapts to the presence of the calcium and positive changes can only be measured from a functional standpoint. As before, if Phase Three Subluxation Degeneration is left unchecked it slowly advances onward into the next phase.

Phase Four Subluxation Degeneration

Phase four subluxation degeneration is seen with subluxations that have been raging on uncorrected or altered for over sixty five years. Phase four is a grave condition that will negatively affect the patient’s longevity and quality of life. The massive amount of neurological damage caused by years of subluxation that have lead to phase four are probably taking a serious toll on this person's health status. X-rays in phase four show serious severe structural changes. Vertebrae exhibit massive calcium changes, disc spaces appear blurred, and the bones themselves appear fused. In this scenario the patient will have a severe restriction of range of motion in addition to probably a number of other health issues. Reconstruction may not be possible in phase four, but care can be directed to some reduction in subluxation with the goal of improvement in the quality of life remaining. Patients in Phase Four Subluxation Degeneration have a serious situation both structurally and neurologically, but they are certainly not beyond hope. Many patients in phase four report significant improvements in symptoms, conditions, mobility and quality of life.

It should be noted that the above are common guidelines and not hard rules. Every person is dynamic and different. People degenerate at different rates and heal at different rates. The further along your spine may be with subluxation degeneration the more strenuous and time consuming your road to improvement will be. For this reason we always stress early care to stop and prevent the advancement of subluxation degeneration. Of course, if you're not under chiropractic care, the best time to start is NOW!

Differential Diagnosis

What else can be causing my neck pain? Diagnosing degenerative disorders of the spine starts with a good history and physical examination. Typically, patients have neck pain. This is the most common complaint. Unfortunately, neck pain is a common complaint in the vast majority of people who have nothing more than a stiff neck. It is important to differentiate neck pain related to degenerative spinal disorders from other more serious ailments.

Muscle strains can cause mild pain. This can vary from the occasional "stiff neck" (from keeping your neck in one position too long, such as during sleep) to neck soreness associated with a low-speed motor vehicle collision (whiplash). The pain and tenderness is not deep and is usually limited to the surrounding muscles around the neck. Often, one side is more symptomatic than the other. Muscle strains are differentiated from degenerative disorders by their self-limited course. Muscle strains usually resolve, or at least dramatically improve, within a couple of days to weeks. Pain that continues for more than three weeks without improving may not be a muscle strain and other diagnoses should be considered.

Patients with rheumatoid arthritis (room-ah-toyed arth-rye-tis) can have neck pain. It is important to recognize this. Any patient with rheumatoid arthritis should have neck x-rays taken. These patients can develop instability in the upper cervical spine that can endanger the spinal cord. This is easily recognized on plain x-rays.

Neck pain can be a presenting symptom of meningitis, an infection of the brain and spinal cord linings. Meningitis can have many causes and may be contagious. Although neck pain is probably the most common symptom, it is important to recognize the others signs. Patients often are extremely sensitive to light, irritable, have high fevers, and actually tolerate very little movement of the neck. Though it is rare, this diagnosis is very serious and should prompt an individual to seek urgent medical care. Other types of infection can also occur in the neck. Infection can occur in the bone or intervertebral disc. This is more common in older patients who may have a weak immune system. Again, as with meningitis a history of fever could be important, but there is not hypersensitivity to bright light.

Tumors can also cause neck pain. One way to clinically differentiate tumor from degenerative disorders is the presence of generalized or constitutional, symptoms. Unintentional weight loss, feeling of extreme lethargy, persistent low grade fevers, and night sweats are typical constitutional symptoms. A history of cancer elsewhere is also a clue, as the majority of neck tumors are metastases (or spread) from a cancer in the lung, prostate, kidney or breast.

Cervical Stenosis

As discussed above, cervical stenosis means, literally, tightening or narrowing of the canal around the spinal cord. Of the degenerative disorders discussed in this chapter, it is potentially the most serious. If the cervical stenosis is profound enough, it can cause dysfunction of the spinal cord known as myelopathy (my-il-lop-ah-thee). The typical person who has cervical stenosis and myelopathy may be in his or her fifties or early sixties. The patient often has complained of neck pain for many years. In some cases, the pain can actually be mild. Therapy may have been prescribed, in addition to medications, for the pain. The other features of this disorder will be demonstrated in an illustrative case.

Cervical Herniated Disc

Just as in the lumbar spine, cervical spine discs can herniate and cause pain, numbness, tingling, or even spinal cord compression. Typically, patients complain of neck pain associated with pain radiating to one arm. This is termed radiculopathy (rah-dick-u-lop-ah-thee). Patients who have herniated cervical discs are younger and often more active than those with cervical stenosis. The disc herniation may be associated with a particular incident, such as a sudden jerking movement or positioning of the neck. Both operative and non-operative methods of treatment can be effective in relieving symptoms.

Cervical Spondylosis

Cervical spondylosis (spon-dee-low-sis) can be thought of as "grey hair" of the spine. This means that if you live long enough (and that may only mean forty- to fifty-years of age in some populations) x-rays of your spine will eventually show signs of cervical spondylosis.

As described above, the term refers to osteophytes (os-t-o-fights), or bony overgrowths, that protrude from the vertebral bodies as well as narrowing occurring across the disc spaces as the disc degenerates. Though they can compress the spinal cord or a spinal nerve root, the vast majority of these osteophytes do not cause any nerve problems. They are a sign, however, that the disc between the vertebrae and the facets (fah-sets) has become degenerative.

Degenerative discs can cause pain. The mechanism of pain is, unfortunately, not well understood. It is thought to be transmitted by tiny nerve endings that innervate the back part of the disc and facet joints. Degeneration can cause pain from the disc, facet joint, or both concomitantly. Diagnostic efforts are aimed to determine which of these structures are generating pain. Therapy is directed to relieving stresses being placed on these areas.

Conclusion

Degenerative disorders of the spine continue to be a significant cause of neck pain in today's population. Understanding of these problems continues to grow. With that, patients' understanding should follow suit. Affected patients should be aware of the possible treatment modalities, including medication, therapy, braces, selective injections, and surgery. The best patient is an informed one who understands the natural progression of these disorders, as well as the benefits, risks, and complications of available treatments. Call us today at 408-739-2273 to make an appointment.

This article is an excerpt from a book titled Save Your Aching Back and Neck, A Patient's Guide (Second Edition, May 2002, completely revised).