INTRODUCTION

Over 75% of all Americans will experience back pain at some point in their lives. This results in billions of dollars in direct health care costs, lost wages, and collateral costs (ie. nursing home admissions, home care, etc.). So we have to face that most of us will have back pain at some point.

Most back pain in the United States is caused by a weakening or wearing of the structures of the low back. In some cases there is a genetic tendency. While in other cases we just "beat up" our back with the activities in our life.

Smoking, obesity, occupations that involve operating machinery that vibrates, genetics, and sports activities that stress the spine all contribute in developing lumbar spinal stenosis. Your spine and the structures that support it (ligaments, tendons, discs, and muscles) have a limited capacity to heal after being damaged.

WHAT ACTUALLY IS THE PROBLEM IN LUMBAR SPINAL STENOSIS (LSS)?

In the interior of your back is a canal called the spinal canal. It is a "boney tube" that runs from your neck to your lower back. It is the home for your spinal cord and spinal nerves.

The spinal canal provides protection for your spinal cord (a very fragile structure indeed). Each segment of your spine has the spinal canal within it. As the spine bends so does the canal and your spinal cord.

Any structure that "pinches into" the canal will potentially cause narrowing or "stenosis" (the medical term for narrowing). So you can see that bone overgrowth, disc bulging, tumors, blood, etc. can all cause stenosis.

To make matters more complicated, some people are born with a congenitally small spinal canal. In people born so it takes much less damage to narrow the canal and cause symptoms. So goes the old adage, "choose your parents well."

HOW DOES LUMBAR SPINAL STENOSIS ACTUALLY CAUSE PAIN?

The mechanisms for the pain are many. Here is a brief summary of how the pain is generated:

Compression of the spinal cord: Nerves do not appreciate being squeezed, cut, torn, frozen, burned, "starved" (deprived of blood or oxygen), poisoned, or stretched. The spinal cord is like a cable with thousands of wires in it. Compression "kinks" the wires.

Stretch of the spinal cord: As the spinal canal narrows the spinal cord is "teathered" and stretched.

Ischemia of the spinal cord: Though a rare complcation in spinal stenosis, it is possible to reduce blood flow to the spinal cord as the structual damage pinches blood vessels.

Associated inflammation and degeneration: As the muscles, ligaments, tendons, discs, and boney elements are all close neighbors whose damage causes pain. The process of spinal stenosis effects all the functions of the back structures.

WHAT ARE THE SYMPTOMS AND PHYSICAL SIGNS OF LUMAR STENOSIS?

The symptoms of Lumbar Spinal Stenosis are mostly what you would expect: low back pain, radiating leg pain, numbness in the legs and feet, and weakness of the legs.

There are 2 symptoms that are more predictive of lumbar spinal stenosis than other causes of low back pain:

1) Spinal Claudication (claudication is impairment in walking): This is a curious finding that when people walk they get an increase in their low back pain. If they stop walking the pain will often diminish. This must be differentiated from vascular claudication (what you would see if the blood flow was reduced).

2) "Shopping Cart" Claudication: You have probably seen this when you are at the supermarket...people pushing their carts by leaning on them bent at the waist. This is a position of comfort for people with spinal stenosis.

The physical examination will show the usual muscle spasm in the lower back (a general finding in people with back pain), reduced strength in the legs, reduced range of motion of the lumbar spine, and pain when the lumbar spine is forcefully palpated (or touched).

HOW IS LUMBAR SPINAL STENOSIS DIAGNOSED?

The diagnosis of lumbar spinal stenosis requires a thorough history and physical by a licensed primary care practitioner. There is no definitive symptom, or physical finding, or even test that makes the diagnosis. It is the entire picture of the person that makes the diagnosis.

CT Scanning and MRI scanning can diagnose causes for spinal canal narrowing but there are many cases missed by these tests. The symptoms are more important than the tests.

IS THERE TREATMENT FOR LUMBAR SPINAL STENOSIS?

The treatments for lumbar spinal stenosis can be broken down into 2 basic categories:

Non-invasive:

1) Low Back Exercises: This is the best and most effective therapy for LSS. For a good introduction to exercises for low back pain see my post on the topic (click here for a link).backexer1

2) Traction: If the cause for the LSS is disc herniation then this form of therapy can be very effective. The portable traction device called the Disc Doctor WG30 has been found very helpful by people (see product review link).

3) Bracing: Supporting the lower back with a lumbar corset has been found to relieve pain in LSS. This is especially helpful when the distance to be walked is more than 100 feet.

4) Massage Therapy: This form of therapy enhances healing of damaged back structures and releases endorphines in the brain. The pain relief can be very temporary.

5) Manipulative Therapy: Both Chiropractic and Osteopathic Manual Therapies have been shown to give relief in LSS.

6) Ultrasound, Cool Laser, Muscle Stimulation, Hot Packs, Cold Packs, Acupuncture, Trigger Point Injections etc. are all helpful adjuncts to a good low back exercise regimen.

7) Medications: The use of non-prescription and prescription medication can be very helpful in reducing pain and allowing an exercise regimen to be started.

DESPITE ALL THE THERAPY AVAILABLE TO A PERSON WITH LSS MANY WILL CONTINUE IN PAIN. FURTHERMORE, SOME PEOPLE DEVELOP SPINAL INSTABILITY AND SPINAL CORD COMPROMISE AND MUST BE REFERRED FOR INVASIVE THERAPY:

Invasive:

The general mechanism of the invasive approache is to reduce the pressure or stretch of the spinal cord:

1) Epidural Injections: This procedure injects corticosteroids (and perhaps a local anesthetic) into a space around the spinal cord called the epidural space hence they are called epidural injections. The intent is to decrease inflammation around the spinal cord and decrease the pressure on it...they rarely work.

2) Facet Injections: In this procedure corticosteroids (and perhaps a local anesthetic) are injected into the small joints on the top and bottom of the vertebrae called facet joints The intent is to decrease inflammation as in the above...they rarely work.

3) Spinal Laser therapy: In this procedure the spinal canal is entered by way of a small incision in the low back. A fiberscope is used to direct the laser and simultaneously visualize areas of scar tissue that may be applying traction to the spinal cord. If relief is achieved it is rarely permanent.

4) Spinal Decompression: There are many surgical procedures that fall under this category...from a microdiskectomy to an open spinal laminectomy with spinal fusion. The severity of spinal stenosis and instability is what determines the best approach.

Nearly all the procedures in this category do something that none of the more conservative therapies can...there is removal of tissue. Since spinal stenosis is a "crowding" of the spinal canal it stands to reason that something would need to be opened or removed for a permanent effect.

Obviously, open surgical procedures carry much more risk than the closed or conservative measures. The best outcomes with the open surgical procedures will usually occur in people who have neurologic impairment related to their spinal stenosis and spinal instability.

Relief of pain, as the sole reason for an open procedure in spinal stenosis, is usually disappointing. I have seen many times that the individual wants the surgery for one reason and the surgeon is doing the surgery for a different reason.

If you or your loved one is contemplating an open procedure, make sure your surgeon is experienced, his location for the surgery is reputable, and you are on the same page as to what is a reasonable expected outcome.

SUMMARY

We have reviewed the history, physical, diagnostics, and treatments for Lumbar Spinal Stenosis. This is a very difficult chronic pain syndrome to treat conservatively. However, the conservative measures are what usually work the best (given the limited benefits of other modalities).

Invasive surgical procedures should be reserved for the most serious of cases. These would be cases of neurologic impairment or spinal instability.

The best outcomes are generally achieved by way of a graded exercise program. Spinal exercises are effective, inexpensive, and can be followed up with surgery if necessary. Your greatest hope for you or your loved one suffering with LSS resides in exercise (click here for more articles).