Overview

Spinal stenosis is the narrowing of your spinal canal and nerve-root canal along with the enlargement of your facet joints. It may be a result of arthritis or just your body's natural aging process, but it can also come from injury or previous surgery. As your spinal canal narrows, there is less room for your nerves to branch out and move freely. As a result, they may become swollen and inflamed, which can cause pain (Figure 1). Several treatments can help relieve the pain. Each treatment offers benefits, but each has limitations. You and your doctor should determine which treatment is best for you.

The spinal canal

To understand spinal stenosis, it is helpful to understand a little about how your spine works (see Anatomy of the Spine).

Your spine is made of 24 moveable bones called vertebrae that provide the main support for your body, allowing you to stand upright, bend, and twist while protecting your spinal cord from injury. Down the middle of the vertebrae is a spinal canal, inside of which the spinal cord runs from the brain to the first lumbar vertebra. Between each vertebra, a pair of spinal nerves exit from the spinal cord to the left and right and branch out to your body. The spinal nerves act as a "telephone," allowing messages, or impulses, to travel back and forth between your brain and body to relay sensation and control movement. Each of the 24 moveable vertebrae in your spine are separated and cushioned by a gel-filled disc, keeping them from rubbing together. The vertebrae are connected and held to each other by ligaments and joints, called facet joints, allowing back motion.

What is spinal stenosis?

Spinal stenosis is a degenerative disease that happens over time and refers to

• narrowing of the spinal canal (Figure 2)
• enlargement of the facet joints
• stiffening of the ligaments
• bony overgrowth

Stenosis can occur along any area of the spine (cervical, thoracic, lumbar), but is most common in the lumbar area. Nearly every adult's spinal canal narrows with age; however, for most people this will not cause pain. As your spinal canal narrows, it presses on your nerves, causing them to become swollen and inflamed. It's important to remember that it's NOT the actual narrowing of the canal, but rather the irritation of the nerves, that causes pain.

What are the symptoms?

Symptoms may start slowly or occur as a sudden onset of pain. You may feel a dull ache or sometimes sharp and severe pain in different areas, depending on which part of your spinal canal has narrowed.

If you have spinal stenosis in your lower back, or lumbar area, you may experience vague pain in your low back and in one or both legs when walking or standing. As the disease progresses, the symptoms increase with walking shorter distances and standing, often referred to as "neurogenic claudication."

When you stand upright, you place pressure on your nerve roots. The flow of blood around these nerves is blocked, causing pain in your back and legs. Leaning over a supporting object, such as a walker or shopping cart, can help reduce your pain when walking, and sitting down may cause your pain to ease. Simply standing and resting is usually not enough for relief.

If you have spinal stenosis in your cervical spine, or neck area, you may feel pain or numbness in your shoulders or arms. In either case, your back may or may not hurt. You may only feel numbness, weakness, cramping, or general leg or arm pain.

IF YOU EXPERIENCE A LOSS OF BOWEL AND BLADDER CONTROL, OR LOSE FEELING IN THOSE AREAS, THIS IS AN EMERGENCY AND YOU MUST CONTACT A DOCTOR IMMEDIATELY.

What causes spinal stenosis?

As you get older (and as your bones degenerate as part of the natural aging process or from arthritis) a number of changes occur. The cushioning disc between your vertebrae dries out and shrinks. You lose bone mass. Bone spurs develop. Your facet joints can enlarge because of strain and stress. This is your body's attempt to spread stress over a larger area. The larger a joint becomes, the less space is available for your nerve roots as they exit the spinal cord.

Stenosis can also be caused by other degenerative conditions such as spondylosis or spondylolisthesis; traumatic conditions such as tissue swelling after surgery, vertebral fracture, and dislocation; skeletal conditions such as rheumatoid arthritis or ankylosing spondylitis; or metabolic conditions such as Paget's disease or fluorosis, an excessive level of fluoride in the body.

Who is affected?

Stenosis affects both men and women and is most common between the ages of 50 and 70. It also may occur in younger people who are born with a narrowing of the spinal canal or who experience an injury to the spine. Currently, it is estimated that as many as 400,000 Americans, most more than 60 years old, may already have the symptoms of lumbar spinal stenosis.

How is a diagnosis made?

When you first experience pain, consult your family doctor. Your doctor will take a complete medical history to understand your symptoms, any prior injuries or conditions, and determine whether any lifestyle habits are causing the pain. Next a physical exam is performed to determine the source of the pain and test for any muscle weakness or numbness.

Your doctor may order one or more of the following imaging studies: X-ray, MRI scan, myelogram, CT scan, or arterial Doppler study. Based on the results, you may be referred to a neurologist, orthopedist, or neurosurgeon for treatment.

X-ray tests use x-rays to view the bony vertebrae in your spine and can tell your doctor if any of them are too close together or whether you have arthritic changes, bone spurs, or fractures.

Magnetic resonance imaging (MRI) scan is a noninvasive test that uses a magnetic field and radiofrequency waves to give a detailed view of the soft tissues of your spine. Unlike an X-ray, nerves and discs are clearly visible. It allows your doctor to view your spine 3-dimensionally in slices, as if it were sliced layer-by-layer like a loaf of bread with a picture taken of each slice. The pictures can be taken from the side or from the top as a cross-section. It may or may not be performed with a dye (contrast agent) injected into your bloodstream. Besides nerve compression, MRI can also detect bony overgrowth, spinal cord tumors, or abscesses.

Myelogram is a specialized X-ray where dye is injected into the spinal canal through a spinal tap. An X-ray fluoroscope then records the images formed by the dye. Myelograms can show a nerve being pinched by a herniated disc, bony overgrowth, spinal cord tumors, and spinal abscesses.

Regular X-rays of the spine only give a clear picture of bones. The dye used in a myelogram shows up white on the X-ray, allowing the physician to view the spinal cord and canal in detail. This test may be followed by a CT scan.

Computed Tomography (CT) scan is a safe, noninvasive test that uses an X-ray beam and a computer to make 2-dimensional images of your spine. Similar to an MRI, it allows your doctor to view your spine in slices, as if it were sliced layer-by-layer and a picture taken of each slice. It may or may not be performed with a dye (contrast agent) injected into your bloodstream. It is especially useful for viewing changes in bony structures.

What treatments are available?

Since aging of the spine is a natural and irreversible process, treatments focus on relieving or coping with the symptoms of pain and relieving the pressure from the nerves, allowing them to function more normally.

Nonsurgical Treatments

Self care
Using correct posture (see Posture for a Healthy Back) and keeping your spine in alignment are the most important things you can do for your back. The lower back (lumbar curve) bears most of your weight, so proper alignment of this section can prevent injury to your vertebrae, discs, and other portions of your spine. You may need to make adjustments to your daily standing, sitting, and sleeping habits. You may also need to learn proper ways to lift and bend (see Coping with Back Pain). You may be able to slow down the progression of stenosis by not smoking and maintaining a weight that's appropriate for your height and body frame.

Physical Therapy
Exercise is important in managing pain from spinal stenosis. Regular back exercises can strengthen muscles that support your spine, easing pain and preventing further injury (see Exercise for a Healthy Back). Your physical therapist will show you how to make modifications to your daily standing, sitting, and sleeping habits-for example, learning how to lift properly or sitting for shorter periods of time (see Coping with Back Pain).

Physical therapy can strengthen the muscles that support your spine, and stretching exercises encourage your muscles to stay flexible. Check with your doctor before you begin any new exercise program.

Chiropractic
Chiropractic manipulation, or spinal adjustment, is a primary treatment that chiropractors use for patients with back or neck pain. The chiropractor applies pressure to the area that is immobile or not moving properly. Some people have very good results after being treated by a chiropractor.

The philosophy behind chiropractic adjustment is to return the joints to more normal motion. Good joint motion is essential for the health and nutrition of the discs and joints because it permits the exchange of nutrients, fluids, and waste. Good motion helps reduce pain, muscle spasms or imbalance, and improves nervous system function and overall health. Without movement, discs and joints may degenerate more quickly than normal. Motion also reduces the formation of scar tissue, which can lead to stiffness and degeneration.

Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs) - aspirin, naproxen (Naprosyn), and ibuprofen (Motrin, Nuprin, Advil) are examples of nonsteroidal anti-inflammatory drugs used to reduce inflammation and relieve pain.
• Analgesics, such as acetaminophen (Tylenol), can relieve pain but don't have the anti-inflammatory effects of NSAIDs. Long-term use of analgesics and NSAIDs may cause stomach ulcers as well as kidney and liver problems.
• Steroids can be used to reduce the swelling and inflammation of the nerves. They are taken orally (as a Medrol dose pack) in a tapering dosage over a 5-day period. They have the advantage of providing pain relief within a 24-hour period. Steroid injections into the area of your spinal stenosis and nerve compression may be prescribed if your pain is severe

• Epidural steroid injections. This procedure, usually performed under fluoroscopy, involves an injection of steroids and an analgesic numbing agent into the epidural space of the spine to reduce the swelling and inflammation of the nerves. About 50% of patients will notice relief after an epidural injection, although the results tend to be temporary. This procedure is usually done in a series of three, at 2-week intervals, to obtain the best results in the shortest time. If the injections are helpful, the series can be done up to three times a year.
• Facet injections are used for patients with low back pain stemming from inflammation or irritation of the facet joint. They may be performed using a fluoroscope (X-ray), which directs a needle through the skin and muscles to the path of the sensory nerves located in the facet joints. At that point, a mixture of numbing medicine and cortisone is injected into the facet joint.

Holistic therapies
Some patients want to try holistic therapies such as acupuncture, acupressure, nutritional supplements, and biofeedback. The effectiveness of these treatments for spinal stenosis may aid you in learning coping mechanisms for managing pain as well as improving your overall health. For resources in your area visit:

National Center for Complementary and Alternative Medicine (NCCAM) nccam.nih.gov

Ask NOAH About: Alternative (Complementary) Medicine
www.noah-health.org/english/alternative/alternative.html

Whole Health MD www.WholeHealthMD.com

The Natural Pharmacist www.tnp.com

(Mayfield Clinic does not endorse these sites. They are provided as a resource only.)

Surgical Treatments

The surgical technique to treat spinal stenosis is known as decompression, which refers to the opening or "unroofing" of bone to relieve pressure and pinching of the spinal nerves. Also, the ligaments and enlarged facet joints are removed.

• Posterior lumbar laminectomy relieves nerve compression by removing the lamina, or bony arched portion of the vertebra. While you are under general anesthesia, a 4-5 inch midline incision is made in the middle of your back. The surgeon first moves the spinal muscles aside to expose the vertebra. The bony arched portion of the vertebra, called the lamina, is removed (laminectomy) to expose the protective covering of the spinal cord. Also, the thickened joints and ligaments are removed.

• A foraminotomy can be performed in conjunction with the laminectomy to enlarge the openings through which the spinal nerves pass. This frees up space for the nerves and decreases inflammation and swelling.
  
  In some cases, your doctor may decide to fuse together two or more vertebrae to give your spine more stability. This is done by placing bone grafts, usually from your own hip or from a bone bank, across several vertebrae where the lamina was removed. Over time this bone graft will fuse (join together) the two vertebrae to stabilize your spine. In some cases metal plates and screws may be used to create a fusion between one or more vertebrae.
  
  Following surgery, you'll stay in the hospital for 1 or 2 days. Physical therapy is usually recommended to begin 4 weeks after surgery. If you choose to have surgery, your doctor will discuss the specific risks associated with the procedure, and give you realistic expectations for the outcome.

Clinical trials

Clinical trials are research studies in which new treatments - drugs, diagnostics, procedures, vaccines, and other therapies - are tested in people to see if they are safe and effective. Research is always being conducted to improve the standard of medical care and explore new drug and surgical treatments. You can find information about current clinical investigations, including their eligibility requirements, protocol, and participating locations, on the web at: the National Institutes of Health (NIH) at clinicaltrials.gov, sponsors many trials; private industry and pharmaceutical companies also sponsor trials www.centerwatch.com

Current studies
Click here for information about clinical trials conducted by our doctors at local Cincinnati hospitals or call 1-800-325-7787 ext. 5260.

Sources & links

If you have more questions, please contact the Mayfield Spine Institute at 800-325-7787 or 513-221-1100. Additional information is available on the web.

www.spinalstenosis.org

www.spine-health.com

www.yoursurgery.com

http://www.neurosurgerytoday.org/what/patient_e/lumbar.asp

Glossary

ankylosing spondylitis: a chronic inflammatory disease that affects the joints between the vertebrae of the spine, and the joints between the spine and the pelvis. It eventually causes the affected vertebrae to fuse or grow together.

decompression: opening or removal of bone to relieve pressure and pinching of the spinal nerves.

facet joints: joints located on the top and bottom of each vertebra that connect the vertebrae to each other and permit back motion.

fluorosis: a condition caused by consuming too much fluoride in which the teeth and bones are abnormally brittle.

foraminotomy: surgical enlargement of the intervertebral foramen through which the spinal nerves pass from the spinal cord to the body. Performed to relieve pressure and pinching of the spinal nerves.

lamina: flat plates of bone originating from the pedicles of the vertebral body that form the posterior outer wall of the spinal canal and protect the spinal cord. Sometimes called the vertebral arch.

laminectomy: surgical removal of the laminae or vertebral arch of the vertebra to remove pressure on the spinal cord.

ligament: a tough fibrous band that connects bones.

neurogenic claudication: a pain syndrome in the back and legs aggravated by walking and relieved by sitting or bending forward.

Paget's disease: also known as osteitis deformans, a bone disease in which normal bone is destroyed and then replaced with thickened, weaker, softer bone. This weaker bone easily bends and deforms. Most often effects the pelvis, thoracic and lumbar spine, skull, femur, tibia, fibula, and clavicles.

radiculopathy: refers to any disease affecting the spinal nerve roots. Also used to describe pain along the sciatic nerve that radiates down the leg.

spondylolisthesis: when one vertebra slips forward on another.

spondylolysis: a spinal instability in which there is a weakness between the body of a vertebra and the pedicle.

updated: 1.2007