|
© 2006 A.D.A.M., Inc. |
What Is Spinal Stenosis?
Spinal stenosis is a narrowing of the space
called the spinal canal, a small space in the backbone that
contains the spinal cord and the sensory and motor nerve roots
that run from the brain and out from the spinal cord to all parts
of the body. The spinal canal is like a tunnel which runs up and
down the human spine. This canal sits directly behind the bone
blocks which make up the spine, the vertebrae.
A normal spinal canal tunnel contains some free
space between the important neurologic (nerve) structures
it houses, such as the spinal cord and the nerve roots and the
edges of the spinal canal. The canal is surrounded by bone and
ligaments and therefore cannot expand if the spinal cord or nerves
require more room. Therefore, if anything begins to narrow the
spinal canal, there is risk for irritation or injury of the spinal
cord or nerves. The spine may become narrowed in any of three
areas: in the space at the center of the spine, in the canals
where nerves branch out from the spine, and in the space between
the bones of the spine.
When an abnormality causes a narrowing of a
canal then the neurologic (nerve) structures within that
canal can become irritated or compressed. This can lead to a
variety of symptoms ranging from tingling, numbness, and weakness
to severe pain and paralysis. The most common conditions which can
narrow a spinal canal and cause stenosis include
herniated discs (often called
slipped discs), a fracture of the spine, tumors,
infection and degeneration through the aging process.
Stenosis can occur anywhere along the spine but
most commonly occurs in the lower spine (lumbar) region. Lumbar spinal stenosis can
cause nerve compression which leads to persistent pain in the
buttocks, limping, lack of feeling in the lower extremities, and
decreased physical activity. Additional symptoms from lumbar
spinal stenosis include sensations of heaviness, weakness and pain
with walking or prolonged standing. There are several different
forms of lumbar spinal stenosis.
The most common form of lumbar spinal stenosis
is degenerative stenosis,
which occurs to some degree in virtually the entire adult
population as a result of the natural process of aging. This form
of stenosis is a degenerative narrowing of the spinal canal, the
nerve root canals or the intervertebral foramina caused by an
unnatural enlargement (hypertrophy) of intervertebral
discs, bones or ligaments. The narrowing results in compression of
spinal nerves and nerve roots, causing a range of symptoms,
including lower back pain, limping or impaired gait as a result of
reduced blood supply to the leg muscles (neurogenic
claudication) and lower extremity pain.
Congenital lumbar
stenosis is relatively rare and usually appears at an
early age, often between 30 and 40. The congenital form of spinal
stenosis is seen in individuals who are born with a narrow spinal
canal. In these individuals, even minimal changes in the structure
of the spine brought on by age can cause severe spinal stenosis.
Congenital spinal stenosis is largely a mysterious condition that
can neither be predicted nor prevented. The onset does not
distinguish by sex, race, or ethnicity, and is not associated with
any particular occupation or any particular body type.
Acquired lumbar spinal
stenosis is more common and generally develops in
persons who are in their 60s or older. This form of stenosis is
caused by progressive changes in different spinal elements (such
as the discs, joints, ligaments, etc.) As people age, all these
different elements sag or bulge and form arthritis that narrows
the spinal canal.
Treatment for spinal stenosis ranges from
physical therapy to epidural injections and finally surgery in
certain cases. Arthroscopic surgery for spinal stenosis has a high
success rate in patients carefully selected for this procedure. It
remains a useful approach in treatment when other options have
been exhausted and after careful review of risks and benefits with
the patient.
For
more information:
www.spinaldisorders.com |