Spinal Stenosis frequently accompanies serious spinal conditions in the lower back. The word “Stenosis” means narrowing. When we refer to a stenosis somewhere in the spine, we are describing a narrowing that usually results in a compression on sensitive nerve fibers. This compression due to spinal stenosis results in a cascade of pain signals along the affected nerve.
In the accompanying diagram we are looking from above down at typical examples of spinal stenosis in the lumbar spine. The diagram demonstrates three different types of spinal stenosis, each of which is quite common. Let us take a moment to simplify the big words and explain each of them.
- Central Stenosis
- Lateral Recess Stenosis
- Foraminal Stenosis
Let’s begin with Central Stenosis. If you look at the diagram you will see the spinal cord depicted in gray as it travels down from the brain in the center of the spinal column. When this space is narrowed, perhaps by a thickened damaged ligament, a bulging or herniated disc, perhaps by excessive bony growth, the pressure against the spinal cord produces pain that is often experienced in the lower back and down both legs.
Let’s look at Lateral Recess Stenosis. The word “lateral” means to the side, either right or left. The word “recess” refers to the channel or groove that is built into the architecture between the back and front parts of the vertebrae and this is where the nerve root that exits off the spinal cord travels on its way from the lumbar spine to the buttock and then down into the thigh and leg itself. When this recess or channel is narrowed due to excessive bony growth as seen in the diagram, the result is lateral recess stenosis.
This is getting easy, isn’t it?
The word “Foraminal” is quite a mouthful, but its an easy word none the less. It simply means opening or hole. Believe it or not, our bodies are riddled with them everywhere and they usually allow for the passage of either fluid, blood vessels or nerve fibers.
In this case, the foramen (in the single tense) is the opening at the end of the lateral recess where the nerve fiber actually leaves the spine. It is formed where two vertebrae separated by the disc come together. The nerve root passes off of the spinal cord, travels into the lateral recess channel, and then exits through the foramen into the back and down the legs.
There, that wasn’t so hard, was it!
WHAT CAUSES IT?
Spinal stenosis is usually caused by progressive degenerative changes in the spine. This is usually called “acquired spinal stenosis” and can occur from the narrowing of space around the spinal cord due to bony overgrowth (bone spurs) from osteoarthritis, combined with thickening or calcification of one or more ligaments in the back. Stenosis can also be caused by a bulge or herniation of the intervertebral discs. This must be differentiated from the stenosis caused by the bony overgrowth that can occur on the vertebral bodies, or facet joints. Spinal decompression therapy may not be appropriate in moderate to severe cases of spinal stenosis with many spurs and thickened ligaments. On the other hand, if the stenosis of the central canal is primarily from bulging discs, or herniated discs, then non-surgical spinal decompression may be very successful.
Sometimes people are born with a smaller spinal canal. This is called “congenital spinal stenosis” and may become problematic at an earlier age.
WHO GETS IT?
The risk of developing spinal stenosis increases in those who:
- Are born with a narrow spinal canal
- Are female
- Are 50 years of age or older
- Have had previous injury or surgery of the spine
Conditions that can cause spinal stenosis include:
- Osteoarthritis and osteophytes (bone spurs) associated with aging
- Inflammatory spondyloarthritis
- Spinal tumors
- Paget’s disease of the bone
- Previous surgery
HOW IS IT TREATED?
Typically, spinal stenosis is treated with conservative non-surgical therapies. One important therapy is exercise. Keeping the muscles of the hip, back, and legs toned allows for improved stability and will improve walking.
Medications such as nonsteroidal anti-inflammatories (NSAIDs) also may be appropriate and helpful in pain relief. Cortisone injections into the epidural space, the area around the spinal cord, may provide temporary relief to people suffering from this disorder.
Non-surgical spinal decompression therapy may help those with herniated or bulging discs, lateral canal stenosis, and facet syndrome.
Under severe and rare circumstances, surgery to correct this disorder may be appropriate. In these severe cases, nerves to the bladder or bowel may be affected, leading to partial or complete urinary or fecal incontinence. If you experience either of these problems, seek immediate medical care! Decompression laminectomy, which is the removal of a build-up of bony spurs or increased bone mass in the spinal canal, can free up space for the nerves and the spinal cord. However, adequate decompression of the neural elements and maintenance of bony stability are necessary for a good surgical outcome for patients with spinal stenosis.
Several studies report that surgical treatment produces better outcomes than non-surgical treatment in the short term. However, these results tend to deteriorate over time. In addition, lumbar decompressive surgery can be complicated by epidural hematoma, deep venous thrombosis, dural tear, infection, nerve root injury and recurrence of symptoms.
Please be sure to ask if you have additional questions to help you with your understanding of spinal stenosis.
Call today to schedule an appointment with Dr. Grace at 503-684-9698