By Lori Montgomery, MD, CCFP and Chris Spanswick MB, ChB, FRCA, FFPMRCA
Spinal stenosis (say: sti-NOH-sis) is a narrowing of areas in the spine that causes irritation of the spinal cord or the nerve roots as they leave the spinal cord. This is most common after the age of 50, but can happen in younger people if they are born with abnormalities in the spine or if they suffer injuries to the spine. There are seven cervical vertebrae in the neck and five lumbar vertebrae in the low back. These are the areas most often affected by spinal stenosis. Spinal stenosis may cause no symptoms at all. If this is the case, it does not need treatment.
Signs and symptoms
These symptoms can occur in the absence of spinal stenosis. If you have them, it may not mean that you have stenosis, but that you should speak to your doctor about it.
- low back pain, often better with sitting or flexing the low back
- pain radiating into the buttocks and legs, often worse with walking and better with rest (also known as sciatica)
- numbness or tingling feelings in the back or legs
- weakness in one or both legs
- in rare, severe cases, loss of bowel or bladder control or loss of sexual function
- neck pain
- pain that goes into the arms and hands
- numbness or tingling feelings in the arms and hands
- weakness in the arms or hands
- rarely, whole body weakness
There are a number of reasons for spinal stenosis. Some you are born with, and some occur later in life.
Some inherited conditions cause the spinal canal to be more narrow than usual. Others cause abnormal growth of bone, which compress the spinal cord and nerve roots. Scoliosis (curvature of the spine) can also put pressure on nerves.
Normal aging process
As we get older, the normal process of aging involves the ligaments around the spine to thicken. This can progress to the point where they compress the nerves. Other people may form osteophytes (outgrowths of extra bone). This may not cause any symptoms at all, or may start to irritate a nerve.
Another normal age-related phenomenon is that the discs between the bones of the spine start to dry out and become thinner. They may begin to herniate or bulge. Many people with no pain or other symptoms at all will have bulging discs seen on an magnetic resonance imaging (MRI). This may be completely normal. In other people, the disc causes narrowing of the canal in which the nerve root travels. This may cause symptoms.
Osteoarthritis and rheumatoid arthritis
Sometimes osteoarthritis or rheumatoid arthritis can cause these changes to occur. In other people, a condition called spondylolisthesis causes one vertebrae to slip forward on the one below. Rarely, bone tumours or other diseases of bone can cause similar symptoms.
Injuries such as a fall or a motor vehicle crash can also be the cause.
The diagnosis of spinal stenosis is made partly by the description of symptoms and a physical exam. X-rays can be useful in some cases to look for abnormalities of bone such as a tumour or inherited disease. But in most cases, if the symptoms and physical exam suggest spinal stenosis, an MRI or computed tomography (CT) scan is the best way to decide for certain whether the spinal cord or nerve roots are affected. In some cases, more specialized tests of muscle and nerve function are needed to decide whether weakness in arms or legs is related to spinal stenosis.
- For mild to moderate pain, acetaminophen (Tylenol) is often the first step.
- Anti-inflammatory medicines may be prescribed for more lasting or severe pain.
- Stronger opioid medicines can sometimes be used for severe pain.
- Medicines like tricyclic antidepressants (TCAs) and gabapentin or pregabalin can help to change the pain signals created by irritated nerves.
- Cortisone is a hormone that naturally exists in the body. Corticosteroids are based on this hormone, and can be injected into the space around the spinal cord or around the nerve roots to relieve pain. This does not work for everyone and results are often short lived. The procedure can not be done more than three times per year, because corticosteroids can cause damage to the joints in the spine and other side effects if used too often.
- Some authorities recommend glucosamine and chondroitin for osteoarthritis, which can contribute to spinal stenosis. There is less research evidence for these agents than for some other medicines. The current evidence seems to suggest that over the long term (several months), some people have relief by taking them.
Physiotherapy may be needed to help strengthen the deep, spine-stabilizing muscles. This can help reduce pain and improve function. A number of different health care providers have expertise in creating an activity program without flaring pain.
Walking aids, chiropractor, and acupuncture
Using a cane or other walking aids can help to reduce pain, improve your balance, and allow you to be more mobile. Chiropractic manipulation and acupuncture appear to help some people with low back pain from spinal stenosis, although more research is needed to find out who can benefit most from these strategies.
Studies have shown that non-drug therapies can help to reduce pain levels and enhance pain coping. These include:
- activity pacing
- cognitive behavioural therapy
These self-management strategies can help you to improve your function so you can do more and enjoy life more. In fact, recent studies have shown that these techniques can be as effective as surgery.
If you have severe weakness in an arm or leg (that prevent you from using your arm or walking) or if you have lost bowel or bladder function due to spinal stenosis, your doctor will recommend surgery to relieve the pressure right away. Otherwise, non-surgical options are most often suggested first.
Surgery can not alter the original cause of the stenosis. This means that the problem can come back again later. Also, the surgery is mainly meant to improve function in the arms and legs and maintain the health of the spine. Sometimes the pain itself does not change, and in some cases, it becomes worse after surgery.
That said, surgery can be a very effective way to improve function for certain kinds of spinal stenosis. There are a number of different procedures possible. It depends on the cause of the nerve compression, so you should ask your doctor for more information.
National Institute of Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse. Health information: Spinal stenosis. Available online at: www.niams.nih.gov NIH Publication No. 04-5327.
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