Spine Information
Lumbar Spinal Stenosis
Table of Contents
Spinal stenosis describes narrowing inside the spinal canal and
mainly occurs from a combination of aging and degenerative changes in
the spine. Wear and tear on the parts of the spine can cause discs to
bulge, spine ligaments to thicken, and joints near the spinal canal to
become enlarged. These can take up space inside the spinal canal and
put pressure on the spinal nerves. Changes like these mostly affect
people over 60 years of age. However, spinal stenosis also occurs in
younger people who have abnormally small spinal canals from birth.
Spinal stenosis usually causes back pain and leg pain that comes and
goes with activities, such as walking.
Learn about lumbar spinal stenosis including
- what part of the spinal anatomy is affected
- what symptoms are present
- how the condition is diagnosed
- what treatment options are available
Stenosis can occur in all areas of the spine, but it is most common
in the lumbar spine. In order to understand your symptoms and treatment
choices, it helps to start with a basic understanding of the anatomy of
your low back. This includes becoming familiar with the various parts
that make up the lumbar spine and how these parts work together.
The spinal canal is a tube within the bones of the spinal column.
The spinal cord and spinal nerves are normally protected inside this
bony tube. Bordered by bone and tough ligaments, the spinal canal
cannot expand when something crowds the space within the canal.
Normally there is space between the spinal cord and the edges of the
surrounding spinal canal.
Anything that narrows the spinal canal
places the spinal cord and spinal nerves at risk. The lack of space
puts pressure on them, causing irritation and inflammation. Conditions
that can narrow the spinal canal include infection, tumors, trauma,
herniated discs, arthritis, thickening of ligaments, and bone spurs.
Spinal stenosis usually occurs in older people due to years of wear and tear
(degeneration) of the spine. The changes
that happen from this process include thickened ligaments, bone spurs,
facet joint enlargement (hypertrophy), and bulging discs.
In some cases, simply bending over relieves the symptoms. This makes
the spinal canal larger and provides more space so that the blood flow
to the spinal nerves increases. Activities that increase the demand for
blood flow cause the blood vessels to swell and enlarge. If there is no
room for this to occur, the blood flow cannot increase. This causes
pain and weakness because the nerves cannot get enough oxygen to meet
the demand.
Some people have a narrow spinal canal from birth. This does not
mean they automatically feel symptoms of stenosis. But if the spinal
canal is too narrow, it can lead to pressure on the spinal nerves.
People who have a very narrow canal are at risk for stenosis because
even minor crowding inside the spinal canal can lead to symptoms.
The main symptoms of spinal stenosis are felt in the legs-heaviness,
weakness, and pain with walking or prolonged standing. The symptoms are
caused by the nerve roots getting squeezed, which upsets the normal
signals traveling from the brain to the body. Irritation of the nerves
is worse when standing or walking due to pressure and stretching of the
nerves. Symptoms often disappear with rest. Sitting down seems to take
pressure of the nerve roots.
Diagnosing a herniated nucleus pulposus begins with a complete history of
the problem and a physical exam.
You may be asked to take a variety of diagnostic tests. The tests
are chosen based upon what the physician suspects is causing your pain.
The most common diagnostic tests to determine whether you have spinal
stenosis are X-rays of your lower back and an MRI scan. In some cases,
a CT scan may be ordered, either in addition to an MRI or instead of
one.
X-rays
An X-ray
is a process that uses radioactive materials to take pictures of bone.
If the doctor suspects vertebral degeneration, X-rays can be used to
verify: a decrease in the height of space between discs, bone spurs,
nerve bundle sclerosis (hardening), facet hypertrophy (enlargement),
and instability during flexion or extension of limbs. X-rays show
bones, but not much soft tissue. They will definitely be used if
fractures, infections, or tumors are suspected.
MRI
An MRI
can be used to verify loss of water in a disc, facet joint hypertrophy
(enlargement), stenosis (narrowing of spinal canal), or a herniated
disc (protrusion or rupture of the intervertebral disc). View example.
CT Scan
The CT scan
is an X-ray test that can show both bones and soft tissues. The scan
forms a set of cross-sectional images that can show disc problems and
degeneration of bones, such as bone spur formation or facet hypertrophy
(enlargement). CT scan images are not as clear as either X-rays or an
MRI. To make the soft tissues easier to see, the CT scan is often
combined with a myelogram.
Other tests are sometimes used to make sure there are not additional problems causing your back pain.
Conservative Treatment
On your first visit to a back specialist, the initial determination
that must be made is the seriousness of the problem. Some problems need
immediate attention-possibly even surgery. The vast majority of back
problems do not require surgery. Spinal stenosis is a slowly
progressive back problem that may respond to conservative care.
A variety of treatment options exists for spinal stenosis. In most
cases, simple therapies such as mild pain medications and rest are
effective in relieving the immediate pain. Physical therapy may be
beneficial if symptoms are not relieved with simple measures. The
overall goal of treatment is to make you as comfortable as soon as
possible, and to get you back to normal activity in a timely manner.
Medications
Mild pain medications can reduce pain when taken properly. The
medications will not cure or stop the progression of the problem, but
they will help with pain control.
Physical Therapy
If your condition is causing only mild symptoms and does not appear
to be getting worse, your doctor may have you work with a physical
therapist. A well-rounded rehabilitation program assists in calming
pain and inflammation, improving your mobility and strength, and
helping you do your daily activities with greater ease and ability.
Positions, movements, and exercises are prescribed to reduce pain.
Treatments may also include lumbar traction to gently stretch the low
back, easing pressure on the spinal nerves. Exercises are used to
improve cardiovascular fitness and to tone the low back and abdominal
muscles. Therapy sessions may be scheduled two to three times each week
for up to six weeks.
The goals of physical therapy are to help you
- learn to manage your condition and control symptoms
- learn correct posture and body movements to reduce back pain
- maximize flexibility and core strength
- foster heart and lung fitness
ESI
An epidural steroid injection (ESI)
can be used to relieve the pain of stenosis and irritated nerve roots,
as well as to decrease inflammation. Injections can help reduce
swelling from inflamed tissues in the spinal canal, which may result in
less irritation on the nerves. The steroid injections are a combination
of cortisone (a powerful anti-inflammatory steroid) and a local
anesthetic that are given through the back into the epidural space.
Epidural steroid injections are not always successful in relieving
symptoms of inflammation. They are only used when conservative
treatments have failed. Learn more about spinal injections.
Surgical Treatment
Spinal stenosis may continue to get worse over time. Surgery may be considered as a treatment option if
- you experience an increase in the weakness in your legs
- you can no longer walk without leg pain
- you begin to have trouble controlling your bowels or bladder
- the pain becomes unbearable
Because spinal stenosis is more common in elderly people, one of the
considerations for suggesting surgery is the overall physical condition
of the patient. Back surgery is a major undertaking. If you have
serious medical problems, the risks may be too great to have spine
surgery. The decision is jointly made with your surgeon and your
regular medical doctor.
The main goal of any surgical procedure used to treat spinal
stenosis is to remove the pressure on the nerve roots in the lumbar
spinal canal. This means that the tube of the spinal canal must be made
larger, and any bone spurs that are pushing into the nerve roots must
be removed. This type of surgical procedure is usually called a
decompression of the lumbar spine, or a decompressive laminectomy of
the lumbar spine.
In order to free up or "decompress" the nerves, the surgeon must remove
a section of bone from the back of the spine (lamina). The surgeon may
also have to remove a portion of the facet joints. The lamina and facet
joints normally provide stability in the spine. Removal of either or
both can cause the spine to become loose and unstable. When this
occurs, doctors will include fusion
as part of the procedure. Likewise, patients with spinal instability
who need surgery for spinal stenosis will likely also need lumbar
fusion.
|
