Pain management and spinal stenosis

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 lower 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 of spinal stenosis including:

• Ageing: 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 discs 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, also called spondylolisthesis. When one vertebra slips forward onto another, that can narrow the spinal canal.
• Tumours 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.

What are the symptoms of spinal stenosis?

Spinal stenosis may result in lower 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:

• Frequent falling and clumsiness
• Pain and difficulty when walking
• Numbness, tingling and hot or cold feelings 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 injuries. Often, unusual leg symptoms are a clue to the presence of spinal stenosis.

If simple treatments, such as changes to posture or nonsteroidal anti-inflammatory medicines, do not relieve the problem, special imaging studies may be needed to determine the cause of the problem. An MRI (magnetic resonance image) is the most likely imaging study to be requested or rarely a CT (computed tomography) scan may be requested. These studies can offer details about the bones and tissues and help with diagnosis.