Spinal stenosis is the narrowing of spaces in the spine (backbone) which causes pressure on the spinal cord and/or nerves. About 75% of cases of spinal stenosis occur in the low back (lumbar spine). In most cases, the narrowing of the spine associated with stenosis compresses the nerve root, which can cause pain along the back of the leg.

What Causes Spinal Stenosis?

There are many potential causes for spinal stenosis, including:

• Aging: With age, the body's ligaments (tough connective tissues between the bones in the spine) can thicken. Spurs (small growths) may develop on the bones and into the spinal canal. The cushioning disks between the vertebrae may begin to deteriorate. The facet joints (flat surfaces on each vertebra that form the spinal column) also may begin to break down. All of these factors can cause the spaces in the spine to narrow.
• Arthritis: Two forms of arthritis that may affect the spine are osteoarthritis and rheumatoid arthritis.
• Heredity: If the spinal canal is too small at birth, symptoms of spinal stenosis may show up in a relatively young person. Structural deformities of the involved vertebrae can cause narrowing of the spinal canal.
• Instability of the Spine, or Spondylolisthesis: When one vertebra slips forward on another, that can narrow the spinal canal.
• Tumors of the spine: Abnormal growths of soft tissue may affect the spinal canal directly by causing inflammation or by growth of tissue into the canal. Tissue growth may lead to bone resorption (bone loss due to overactivity of certain bone cells) or displacement of bone and the eventual collapse of the supporting framework of the spinal column.
• Trauma: Accidents and injuries may either dislocate the spine and the spinal canal or cause burst fractures that produce fragments of bone that penetrate the canal.
• Paget's disease: This chronic (long-term) disorder usually results in enlarged and deformed bones. The disease can affect any bone of the body, but is often found in the spine.
• Fluorosis: This is an excessive level of fluoride in the body. It may result from chronic inhalation of industrial dusts or gases contaminated with fluorides, prolonged ingestion of water containing large amounts of fluorides, or accidental ingestion of fluoride-containing insecticides. The condition may lead to calcified spinal ligaments or softened bones and to degenerative conditions like spinal stenosis.

What Are the Symptoms of Stenosis?

Stenosis may result in low back pain as well as pain in the legs. Stenosis may pinch the nerves that control muscle power and sensation in the legs. Additional symptoms may include:

• A foot-slapping gait
• Frequent falling, clumsiness
• Pain and difficulty when walking
• Numbness, tingling, hot or cold feelings in the legs
• Weakness or a heavy and tired feeling in the legs

How Is Spinal Stenosis Diagnosed?

Spinal stenosis can be difficult to diagnose because its symptoms can be caused by other conditions. Usually, people who develop stenosis have no history of back problems or any recent injury. Often, unusual leg symptoms are a clue to the presence of spinal stenosis.

If simple treatments, such as postural changes or nonsteroidal anti-inflammatory drugs, do not relieve the problem, special imaging studies may be needed to determine the cause of the problem. An MRI (magnetic resonance image) or CAT (computed tomography) scan may be requested. A myelogram (an X-ray taken after a special fluid is injected into the spine) may be performed. These and other imaging studies can offer details about the bones and tissues and help with diagnosis.

How Is Spinal Stenosis Treated?

• Changes in posture: People with spinal stenosis may find that flexing the spine by leaning forward while walking relieves their symptoms. Lying with the knees drawn up to the chest also can offer some relief. These positions enlarge the space available to the nerves and may make it easier for people with stenosis to walk longer distances.
• Medications: In some cases, the pressure on the nerves is caused by inflammatory swelling. Nonsteroidal anti-inflammatory medications such as aspirin or ibuprofen may help relieve symptoms.
• Rest: Rest, followed by a gradual resumption of activity, can help. Aerobic activity such as bicycling is often recommended.
• Weight loss: Losing weight can also relieve some of the load on the spine.
• A lumbar brace or corset: These devices provide some support and can help the patient regain mobility. This approach is sometimes used with people who have weak abdominal muscles or older patients with degeneration at several levels of the spine.
• Surgery: If other treatments do not ease the pain, surgery may be recommended to relieve the pressure on affected nerves.

Reviewed by the doctors at The Cleveland Clinic Department of Pain Management

WebMD Medical Reference provided in collaboration with the Cleveland Clinic

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