Lumbar Spinal Stenosis

Overview of the causes, symptoms, diagnosis and treatment of lumbar spinal stenosis; a common cause of low back, buttock and leg pain.

Written by Joshua M. Ammerman, MD

Lumbar spinal stenosis is a common cause of low back, buttock and leg pain in adults 50 years and older. This condition is caused by nerve compression and symptoms may include tingling, numbness and weakness. Leg symptoms are sometimes described as sciatica or lumbar radiculopathy.

Lumbar Spinal Stenosis Causes
Most people who have spinal stenosis in their low back have developed it during their lives—this is known as acquired spinal stenosis. A few people are born with lumbar spinal stenosis—also called primary or congenital spinal stenosis. Below several causes or contributing factors of acquired lumbar spinal stenosis are explained.
Degenerative disc disease is not really a disease but a condition that develops from wear and tear, injury and aging. The process of growing older causes gradual changes in the spine at the cellular level. Over time, discs may gradually lose their ability to retain water causing a disc to flatten, lose its normal shape and resiliency—changes that affect its structure and strength. Such changes increase the risk for a disc to bulge or herniate. A disc herniation occurs when the disc’s soft jellylike core (nucleus pulposus) spills outside the disc’s wall (annulus pulposus) causing swelling and acute pain.

Each intervertebral disc separates adjacent vertebral bodies from one another. The space the disc creates between the bones permits nerves to exit the spinal column on each side. Loss of disc height can reduce the size of that space, narrow the neural foramen (nerve passageways) and compress the nerves. A disc that bulges or herniates also can compress a nearby nerve root and/or push into the spinal canal and encroach on the nerves collected within the spine, the so-called cauda equina.
Another degenerative disorder is spinal osteoarthritis, also called spondylosis. This type of arthritis may trigger development of bone spurs (osteophytes) on bony edges of the vertebral bodies and where bone meets, such as the facet joints. Bone spurs may grow or push into the lumbar spine’s nerve roots and/or spinal canal.

Another cause of lumbar spinal stenosis is spondylolisthesis. This condition develops when a vertebral body in the low back slips forward (or backward, retrolisthesis) on the neighboring vertebrae, narrowing the spinal canal, leading to compression of the spinal nerve roots.

Less common causes include lumbar degenerative scoliosis (adult onset scoliosis), tumor (benign or cancerous), spinal infection, and Paget’s disease.

Lumbar Spinal Stenosis Symptoms
The symptoms of lumbar spinal stenosis vary, although pain in the low back, buttocks and back of the thighs that worsens when walking and standing and is relieved with sitting are most common. Some people experience no symptoms at all—narrowing in the spinal canal and nerve passageways doesn’t necessarily mean symptoms will occur.

Common symptoms of lumbar spinal stenosis include low back pain and lumbar radiculopathy. Widely known as sciatica, lumbar radiculopathy is pain, numbness, weakness, and/or tingling that radiates from the low back down into the buttocks, legs, and calves. You may experience pain in both legs, though one leg can be worse than the other.

Many people with lumbar spinal stenosis experience symptoms only when they are standing or active. You may not be able to walk a great distance, such as several blocks, before leg pain starts. Sitting or resting only temporarily relieves pain and symptoms, which return after standing and walking.

Severe cases of lumbar spinal stenosis may result in cauda equina syndrome. This develops when the cauda equina is compressed, which is a rare occurrence. Symptoms of cauda equina syndrome may include bladder or bowel incontinence.

Lumbar Spinal Stenosis Diagnosis
Your doctor reviews your medical history and talks with you about your pain and symptoms. Next, he performs a physical and neurological exam and compares the findings to your pain and symptoms. An x-ray and/or other diagnostic studies (MRI, CT scan or an EMG) may be ordered to evaluate your anatomical structures in your low back, including the spinal canal and neural foramen. Imaging tests are essential to identify the cause of spinal stenosis (eg, spondylosis, disc herniation) and confirm your diagnosis.

Lumbar Spinal Stenosis Treatment Options
During your conversation with your doctor, he will ask about treatments you’ve already tried to help relieve and manage your low back pain and spinal stenosis symptoms. Previous therapies may have been provided by another doctor or practitioner (eg, pain management specialist, physiatrist). Insight into treatments that helped and those that were ineffective is important to developing your treatment plan.

It’s important to know that lumbar spinal stenosis is rarely an urgent surgical situation; in fact, many patients do not need spine surgery. Rather, non-surgical treatments often effectively manage pain and symptoms related to spinal disorders that cause spinal canal and/or nerve compression. Some therapies are combined and may include a treatment that was previously ineffective.

Non-operative therapies may include:

Spine surgery may be considered or recommended if non-operative therapies are ineffective, your symptoms progressively or worsen, you have significant weakness or pain or the inability to walk becomes intractable or difficult to manage.

Surgery to treat lumbar spinal stenosis:

The primary goals of surgery for lumbar spinal stenosis are to:

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Spinal Stenosis Symptoms