Spinal Stenosis (Cervical)
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.
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.
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.