Stenosis – Cervical Spine

Most neck pain is due to degenerative changes that occur in the intervertebral discs of the cervical spine and the joints between each vertebra. Perhaps the most serious of the problems caused by degeneration of the spinal segment in the cervical spine is the condition of spinal stenosis.

In the late stages of spinal degeneration, bone spurs from the degenerative process can cause a condition known as spinal stenosis. As the bone spurs form, the size of the spinal canal becomes smaller. The bone spurs begin to press on the spinal cord or the nerve roots. Pressure on the nerves in the spinal cord can cause numbness, tingling, or pain in the arms, hands, and legs. This condition is sometimes called cervical myelopathy. It is from the simpler problem where only one nerve root is being pinched by a herniated disc or a bone spur.

Causes

To really understand cervical spinal stenosis you first need an understanding of the wear and tear process, called disc degeneration. To help you understand disc degeneration, compare a spinal segment to two vanilla wafers (the “vertebrae”) and a marshmallow (the “disc”). Imagine a fresh marshmallow between the two wafers. When you press the wafers close together, the marshmallow gives or “squishes out”. Suppose you leave the marshmallow out for a week and it starts drying out. When you press it between the wafers, it is not quite as spongy. If you press hard enough, the outside of the marshmallow may even tear or split. Suppose you left the marshmallow out for a month. It would probably be so dried out it would be hard and very thin and would not have any “shock absorbing” ability.

As we age, the disc loses some of its water content and, as a result, some of its shock absorbing ability. Like the marshmallow, the first changes that occur in the disc are tears in the outer ring of the disc, called the annulus. Tears in the annulus may occur without symptoms. Therefore, you may not notice when they occur or what caused them. These tears heal by forming scar tissue. Scar tissue is weaker than normal tissue. Repeated injuries and tears cause more wear and tear to the disc. As the disc wears, it loses more of its water content. It becomes less and less “spongy”, eventually no longer able to act as a shock absorber.

As the disc continues to wear, it begins to collapse. The space between each vertebra becomes smaller. The collapse also affects the way that the facet joints in the back of the spine “line up”. Like any other joint in the body, the change in the way the bones fit together causes abnormal pressure on the articular cartilage. Articular cartilage is the smooth shiny material that covers the end of the bones in any joint. Over time, this abnormal pressure causes wear and tear arthritis (osteoarthritis) of the facet joints.

Bone spurs may form around the disc and facet joints. It is thought that too much motion in a spinal segment causes the bone spurs to form. Eventually, bone spurs can form around the nerves of the spine, causing a condition called spinal stenosis.

Symptoms

When there is narrowing of the spinal canal, the bony tube through which the spinal cord runs, the whole spinal cord may be affected. This is different than when the bone spurs only narrow one of the foramen – the openings where the nerve roots exit. The symptoms are much different. A pinched nerve from either a herniated disc or a bone spur rarely affects the legs. Cervical myelopathy can affect both the arms and the legs.

Pressure on the spinal cord, as it runs through the cervical spine, can cause many symptoms. Cervical stenosis can cause weakness and spasticity in the legs. Spasticity means you to lose control over your legs and you may have a great deal of difficulty walking due to loss of control of where you place your feet. You may have numbness in both the upper extremities and the lower extremities. Your reflexes may be increased in the legs. You may lose the strength in your legs. You may lose your “position sense”. This is the sensation that allows you to “know” where your arms and legs are when you have your eyes closed. For example, you may not be able to tell whether your arm is up in the air or down by your side, unless you can see it.

Diagnosis

Finding the cause of your neck problem begins with a complete history and physical examination. After the history and physical exam, the doctor will have a good idea of the cause of your pain. To make sure of the exact cause of your neck pain, he can use several diagnostic tests. These tests are used to find the cause of your pain, not make your pain better. Regular X-rays, taken in the doctor’s office, are usually a first step in looking into any neck problem and will help determine if more tests are needed.

Treatment:
Adjustments are typically indicated except in very advanced conditions. Typically, high-velocity, low-amplitude manipulation (the kind of adjustment you think of that comes with a ‘pop’) is NOT indicated. More often, manual therapy is used to restore proper joint movement. Unfortunately, some cases of Spinal Stenosis can be advanced before the patient’s first visit into the chiropractic clinic. Orthopedic consult is often necessary if 50% pain relief is not achieved after 2 weeks of Chiropractic treatment.