Spinal Stenosis

Spinal stenosis is a general term referring to the narrowing of spaces in the vertebral column. Anatomically, individual vertebras interconnect in several places, making canals and holes through which nerves and the spinal cord pass. In spinal stenosis, pressure is put on the nervous tissue that traverses these openings. Because the nature of nervous tissue is to provide sensation, this pressure causes pain.

While spinal stenosis can be caused by many factors, most cases are due to aging and the related presence of osteoarthritis. When osteoarthritis of the spine develops to the point where the intervertebral disk has worn away and bone rides on bone, the body attempts to remedy this painful condition by forming bone spurs.

Depending upon their location, these bones spurs may compress the spinal cord and/or nerve roots.

Another aging-related way stenosis develops is the degenerative changes in spinal ligaments. Spinal ligaments stiffen and thicken over time in many people. This, in turn, compresses and shortens the spine. The compression will put pressure on the nerve roots, and will likely cause pain.

About 75% of spinal stenosis cases are lumbar spinal stenosis (LSS).

Signs and Symptoms of Spinal Stenosis

The signs and symptoms of lumbar spinal stenosis include:

• Sciatica pain
• Radiating pain, with numbness, tingling and weakness of one or both legs
• Foot or gait problems, especially a slapping foot during walking
• Loss of balance
• An extreme form of LSS - cauda equina - interrupts bowel, bladder and sexual function and the weakness of the legs is very pronounced. Cauda equine is a very serious form of lumbar spinal stenosis, and requires immediate medical attention.

In 25% of cases, stenosis affects the cervical area of the spine. Symptoms for cervical spinal stenosis include:

• Pain in the neck, back, shoulders, and arms
• Pain, numbness, weakness, cramping in arms

Sometimes diagnosing spinal stenosis is difficult, because the signs and symptoms are shared with other conditions.

In these cases, medical imaging can be helpful.

Causes of Spinal Stenosis

As mentioned in the overview, most of the time, spinal stenosis is caused by the degenerative changes associated with aging. There are other causes, however, spinal stenosis can be categorized as either primary, which is basically congenital, or acquired. Most cases of spinal stenosis, certainly the types discussed earlier, are acquired. Other causes of spinal stenosis are:

• Tumors, which press on the spinal cord and nerve roots. Most spinal tumors are found between the vertebrae and the spinal cord, but may be in other areas as well. Tumors can occur anywhere in the spine.
• Injury from car accidents and other kinds of trauma pulls the spine out of alignment, putting pressure in abnormal places in the spine, including nervous tissue. Trauma may also cause bone or burst fractures. In either case, the spinal cord and/or nerve roots will be affected.
• Heredity, (including achondroplasia), or a small spinal canal present at birth will manifest symptoms in younger people.
• Paget's Disease, is a bone disease in which bones enlarge and become deformed, and encroach on the spaces in the spine.
• Flurosis, or an excess of fluoride in the body can calcify spinal ligaments, which will compress and shorten the spine.

Diagnosis of Spinal Stenosis

Several forms of medical imaging can be used to diagnose spinal stenosis. They are:

• X-Rays
• MRI, or magnetic resonance imaging
• CT, or computerizes axial tomography
• Myelogram
• Bone scan

The two MRI images above show how the spine can narrow the canal and put pressure on the nerves.

Non-Surgical Treatment of Spinal Stenosis

Of course, it is best to first try the non-surgical approach to treating and managing spinal stenosis. The following  may be helpful:

• NSAIDS will reduce pain and inflammation. However, NSAIDS have side effects. Add to this that exceeding the recommended doses won't increase the pain relieving effects of NSAIDS. For this reason, it is best to carefully consider the use of NSAIDs in cases of severe pain.
• Analgesics such as Tylenol will reduce pain but not inflammation. It's an analgesic if it contains acetaminophen. Overuse of analgesics will cause liver and kidney damage. Using alcohol with analgesics will amplify these side effects.
• Supplements such as chondrotin and glucosamine, may be helpful, but the jury is still out on how these affect spinal arthritis.
• Rest and restricted activity with a gradual return is a common sense way to improve symptoms.
• Walking and biking are good bets for workouts.
• Physical therapy that builds the strength and endurance of spinal muscles.
• Back support belts.

Minimally Invasive Treatment for Spinal Stenosis

There are two minimally invasive techniques for treating spinal stenosis. These are epidural steroid injections and spinal cord stimulation.

• Epidural steroid injections in some patients can provide significant, long-term pain relief. They provide an option to more aggressive treatment such as surgery or spinal cord stimulation. In elderly patients who are poor surgical risks, they can provide in selected patients, significant, long-term pain relief. (Caudal and Cervical Epidural injections)
• Spinal cord stimulation is an exciting somewhat newer technique for the management of pain. In selected patients a trial can be performed to determine whether this form of therapy will be effective. If so, the system can be implanted similar to a pacemaker with a small battery under the skin and the electrodes placed in the spinal canal. By stimulating the spinal cord in the appropriate location, this can provide stimulation in the painful area which alleviates the pain in some patients.

Surgical Treatment of Spinal Stenosis

The purpose of surgery for spinal stenosis is to relieve pressure on the spinal cord and/or nerves, and also to provide spinal stability. The most common surgery performed for spinal stenosis cases is the decompressive lumbar laminectomy. In this procedure the lamina and spinous process of the vertebra are removed. Other areas encroached upon by bone are trimmed down.

Other surgical procedures for spinal stenosis are:

• Laminotomy, in which only a portion of the lamina is removed.
• Spinal fusion, in which 2 neighboring vertebrae are fused together using a piece of bone, usually taken from the patient's pelvic bone.

Surgery is not a cure all, so the decision to use it as a treatment for spinal stenosis is a serious one, requiring careful consideration.

Additionally there are risks associated with surgery, including but not limited to infection, deterioration of the nerves, deep vein thrombosis and a tear in the meninges at the place of surgery. A tear in the meninges can lead to arachnoiditis. Most of the time surgery for spinal stenosis is performed on older people, so other complications may arise, depending on the patient's condition.

Preventing Spinal Stenosis

Common sense can go a long way in preventing spinal stenosis:

• Maintain an ideal weight to avoid placing extra compressive stress on the spinal bones.
• Use good body mechanics when lifting.
• Exercise regularly. Pilates is a great form of exercise for back support and strength. By placing emphasis on the eccentric phase of muscle contraction, it provides traction to the spine, having a space of increasing effect.