What is Spinal Stenosis?
Spinal stenosis is a condition that occurs when the channels in the spine that contain the spinal cord and nerve roots becomes narrowed or restricted. Stenosis is the medical term for narrowing. Spinal stenosis can compress nerves and the spinal cord and can lead to pain in the lower back and legs or in the neck, arms, and hands, depending on where the narrowing is located. Although spinal stenosis can be found in any part of the spine, the lumbar and cervical areas are most commonly affected.
Lumbar Spinal Stenosis is when the stenosis is located in the lower part of the spine. If it is in the upper part of the spine, it is called cervical spinal stenosis.
One of the most common causes of spinal stenosis is osteoarthritis of the spinal column. People suffering from spinal stenosis may have trouble walking for any length of time or for long distances, and may need to sit down frequently or lean over to relieve the pain. Or they may have tingling, pain, or numbness that runs down their arm and into the hand. Symptoms of spinal stenosis include the follow and vary from patient to patient since narrowing of the channels in the vertebrae do not always compress the spinal cord or nerves:
- Trouble walking for a long period of time or long distances
- Need to sit down frequently to relieve pain
- Need to lean over to relieve the back pain
- Pain or cramping in your legs when you stand for long period of time
Lumbar spinal stenosis can cause pain or cramping in your legs when you stand for long periods of time or when you walk. The discomfort usually eases if you bend forward or sit down, but comes back when you stand upright. This pain is called pseudoclaudication, false claudication, or neurogenic intermittent claudication.
A herniated disc can compress nerves in your lumbar spine leading to pain that starts in your hip or buttocks and extends down the back of your leg. The pain is worse when you're sitting and generally affects only one hip and leg. Other symptoms may include numbness, weakness, or tingling in the leg or foot. The pain may be minor or severe.
Cervical spinal stenosis can cause pain in the neck and shoulders. The pain may be occasional or chronic and can also range from mild to severe. It may radiate down your arm or hand.
Cervical spinal stenosis can also cause:
- muscle weakness
It can also affect the nerves that control your balance, which can lead to clumsiness or a tendency to fall. In severe cases of spinal stenosis, nerves to the bladder or bowel may be compressed, which can lead to partial or complete incontinence. Anyone who experiences problems controlling their bladder or bowels should seek immediate medical attention.
Spinal Stenosis and Your Spinal Anatomy To understand spinal stenosis, it helps to understand the anatomy of the spine. The spine is a column of connected bones called vertebrae. There are 24 vertebrae in the spine, plus the sacrum and tailbone (coccyx). Most adults have seven vertebrae in the neck (the cervical vertebrae), twelve from the shoulders to the waist (the thoracic vertebrae), and five in the lower back (the lumbar vertebrae). The sacrum is made up of five vertebrae between the hipbones that are fused into one bone. The coccyx is made up of small fused bones at the tail end of the spine.
Nerve Structures If you look at an individual vertebra from the top, you see a disc of bone in front and a ring of bone with several prongs (called “processes”) at the back. The disc sections of the vertebrae are separated by rubbery discs of cartilage that pad them from each other. The ring section is called the lamina, and the prongs of adjacent vertebrae are padded with some cartilage where they touch each other. They are also connected by ligaments, which keep the vertebrae in their proper place. The spinal cord, the thick bundle of nerves that extends downward from the brain, passes through the ring in each vertebra, which line up into a channel called the spinal canal. Two nerves branch out of the spinal cord on either side of the spine between each vertebra, through openings called the intervertebral foramina.
Normally, the spinal channel is wide enough for the spinal cord and the intervertebral foramina are wide enough for the nerve roots. But either or both can become narrowed and lead to spinal stenosis.
Understanding the Causes of Spinal Stenosis
Spinal stenosis can be either primary or acquired. Primary spinal stenosis, which is a birth defect, is less common than acquired spinal stenosis, which is the result of disease or injury of the spine. The leading cause of acquired spinal stenosis is wear and tear on the spine due to aging.
The most common direct cause of spinal stenosis is osteoarthritis, where the cartilage that cushions bones has started to degenerate due to age. Cartilage is smooth in most young people, but as it deteriorates with age, it becomes rough and may wear through completely, allowing bones to rub against each other. The body reacts to this rubbing by producing small bone growths called bone spurs. In the spine, these bony growths can narrow the spinal canal.
In addition, the discs between the vertebrae can be squeezed out of position (a herniated disc) or be ruptured or torn. A herniated disc can protrude into the spinal channel or pinch on the nerves extending through the intervertebral foramina. Ligaments connecting the vertebrae may also degenerate and pull one or more vertebrae out of position, which can pinch the spinal cord or nerves.
Risk factors for both osteoarthritis of the spine and for disc problems include poor posture and being overweight. Spinal Stenosis can also be due to an injury to the spine. This can include the kind of injury caused by picking up heavy objects improperly. The spine or spinal canal may be dislocated, putting pressure on the spinal cord and nerves. Fractures to the spine can create fragments of bone that can intrude into the spinal canal. Any injury to the spine can also cause swelling of tissue that can put pressure on the spinal cord or nerves.
Spinal Stenosis - Exams and Tests
Making a diagnosis of spinal stenosis can be difficult because the symptoms can be similar to those of other conditions and because the symptoms can come and go.
To determine the cause of you symptoms, your doctor will probably ask you to undergo several tests. These may include :
- Spinal X-Ray
- Magnetic Resonance Imaging (MRI)
- Computed Tomography (CT) scanning.
- CT myelogram, in which CT imaging is performed while a contrast dye is injected into the spinal column.
- Bone Scan -a different specialized imaging of the bones.
Spinal Stenosis Treatment: Non-Surgical
Spinal stenosis can be treated conservatively with medications and lifestyle modifications. Unless your symptoms are very serious, your physician will probably choose to start out your treatment this way.
The first step is to relieve pain and inflammation where the nerves are compressed. Non-steroidal anti-inflammatory drugs (NSAIDS) include aspirin, ibuprofen (Advil™ or Motrin®), indomethacin and naproxen, among others. These products relieve pain and also reduce inflammation and swelling.
Other nonsurgical treatments for spinal stenosis include:
Rest: Your doctor may suggest that you rest your back by restricting your activities. Rest followed by a slow and gradual return to exercise may help your back heal. Wearing a brace or corset to support the back. A back brace or corset can also help support your back and may be especially helpful for people who have degeneration in more than one area of the spine.
Physical Therapy: A physical therapist can show you exercises to help you build up and maintain strength, endurance, and flexibility for spinal stability. Some of these exercises will help strengthen your abdominal muscles, since they help support the back. Physical therapy can also include the use of heat or ice packs, ultrasound, electrical stimulation, and massage. These treatments can relax tight muscles and ease pain or discomfort.
CorticoSteroid Injections (Epidural Injections): In more severe cases of stenosis, your doctor may inject a corticosteroid medication into the spinal fluid around your spinal cord and nerve roots. This may be referred to as an epidural injection. Corticosteroids can be especially helpful in treating pain that radiates down the back of your leg. Many people report almost immediate relief from the injections.
Treatment of Spinal Stenosis- Surgical
Severe cases of spinal stenosis may require surgery. There are several types of surgery done to relieve pressure on the spinal cord and nerves and to help strengthen the spine. The most common surgical procedures are decompressive laminectomy, laminotomy, and spinal fusion. Only a small percentage of patients with spinal stenosis require surgery.
In decompressive laminectomy, your surgeon removes the lamina — the back part of the bone over the spinal canal — either to release pressure on the nerves, to allow room so that bone spurs or ruptured discs can be removed or both. A laminectomy can be performed laparoscopically, using a tiny camera and surgical instruments inserted through several small incisions.
Laminotomy is a less extensive type of spinal surgery than laminectomy. Just a portion of the lamina is removed. It can be done to relieve pressure on the nerves or to allow access to a herniated disk or bone spur.
Spinal fusion permanently connects—fuses—two or more vertebrae and may be especially helpful in cases when one or more vertebrae slip out of their correct position. It can be done alone or at the same time as a laminectomy. To fuse the spine, small pieces of extra bone from a bone bank or from elsewhere in your body are used to fill the space between two vertebrae. Wires, rods, screws, or plates may be used along with the bone to fuse the vertebrae, especially if your spine is unstable or the surgery is extensive.
Spinal Stenosis – Recovery after Surgery
Recovery from spinal stenosis surgery depends on how extensive the surgery is. For most patients, there will be some pain or discomfort for a couple of days after surgery. On the first postoperative day, you probably can sit up in bed and stand. Over the next couple of days, you should be able to walk fairly comfortably and go up and down stairs without too much trouble.
Usually, a patient is hospitalized for about three days after spinal stenosis surgery. Recovery takes longer if a spinal fusion is performed. This can add two to three days to the hospital stay. The results with surgery to correct spinal stenosis are usually good. Generally, 80% to 90% of patients have relief from their pain after surgery.