Spinal Stenosis As A Cause of Low Back and Lower Extremity Pain

Author: 
J. Michael James, M.D. and Shawna Hill Wilson, ANP-C, Alaska Spine Institute

Spinal stenosis is the leading cause of back pain and lower extremity pain in people over the age of 60. It usually starts gradually for no apparent reason, without any trauma or specific injury, and worsens over time. Spinal stenosis is characterized by the symptoms of low back pain, leg pain, and leg numbness. These symptoms may occur together or separately and are aggravated with activity, specifically, standing and walking. In fact, many times people affected by spinal stenosis have difficulty walking for even a few blocks. For example, many people with spinal stenosis have difficulty completing every day tasks like grocery shopping. They tend to lean forward onto the shopping cart because this tends to reduce the symptoms and allow them to walk for a longer period of time. Additionally, people with spinal stenosis may have a posture that is slightly bent forward at the low back. This mimicks the same posture as leaning on a shopping cart and can provide the same improvement in ability to walk or stand. Also, they may find difficulty walking on a downhill slope and may have difficulty climbing stairs. The symptoms associated with spinal stenosis are usually alleviated with short periods of rest, sometimes as little as two to three minutes.

What is Spinal Stenosis?
There are two classifications of Spinal stenosis. The first class of spinal stenosis is acquired. It is caused by degeneration of the spinal structures due to aging or mechanical stress on the spine. Acquired spinal stenosis is the most common type of spinal stenosis and is what is described in the beginning of this article. The second class of spinal stenosis is due to congenital or developmental abnormalities and problems from this usually appear in the 3rd and 4th decades of life.

There are two types of spinal stenosis. First, there is central spinal stenosis, which is narrowing of the central spinal canal through which the spinal cord and nerve roots run. This type of stenosis is usually caused by bulging of the intervertebral discs as they age and become flattened. Also, enlargement of the joints in the back, called facet joints, from arthritis can further narrow the central canal. The second type of spinal stenosis is called lateral stenosis. In this type of stenosis there is narrowing of the neural foramen, the space where the spinal nerves exit the central canal. Basically, despite the type of spinal stenosis, there is irritation of the spinal cord and/or nerve roots that cause symptoms.

Diagnosing Spinal Stenosis
The diagnosis of spinal stenosis begins with a medical evaluation that includes an extensive history and physical exam. Next, diagnostic tests will be ordered and obtained. These tests can include regular X-rays, MRI (magnetic resonance imaging), CT scan (computed tomography), and EMG study (electromyography). Some or all of these tests are needed to ensure a correct diagnosis and sometimes additional tests are required. This is very important because there are other conditions that can cause symptoms like spinal stenosis. The most common condition is called vascular claudication, blockage of the major arteries of the legs that supply the muscles with blood. Vascular claudication will cause leg pain with activity but rarely is associated with back pain. The differences between spinal stenosis and vascular claudication are listed below.

Characteristic Spinal Stenosis Vascular Claudication

Pain Burning and cramping Cramping, deep aching

Sensory changes Numbness and Tingling None

Reflexes Decreased or absent Normal

Pulses Normal Decreased or absent

Skin Normal Pale, cool, shiny, hair loss

Other conditions that can cause similar symptoms include arthritis of the hip or knee, sacroiliac joint problems, lumbar facet joint arthritits, vertebral body compression fracture, tumor, disc herniation and peripheral polyneuropathy (nerve damage).

How is Spinal Stenosis Treated?
Treatment of spinal stenosis includes conservative measures, interventional care, and as a last resort surgery. The most effective treatment for reducing the symptoms of spinal stenosis is a combination of interventional care (epidural steroid injection) and conservative measures (physical therapy). Epidural steroid injection involves injecting numbing medications (like novacaine) and potent anti-inflammatory medication (cortisone) around the area of stenosis and irritated nerves. Thus, resulting in reduced irritation of the compressed nerves, improved activity tolerance, and decreased pain. Epidural steroid injections are carried out by highly trained physicians in an outpatient surgical suite. Patients are made as comfortable as possible and medication to assist in relaxation can be given if desired. During the procedure, fluoroscopy (real time x-ray) is used so that placement of the needle ad delivery of the medication can be successfully directed to the problematic area. This limits the potential for complications and improves the likelihood of a beneficial outcome. The entire procedure takes only a few hours. Patients are able to return home the same day and resume normal activities the following day. The majority of patients experience dramatic improvement of their symptoms within three days. Occasionally, improvement from the injection can be delayed up to a week until the cortisone becomes fully effective. If relief is incomplete with the first injection a second or third injection may be required three to four weeks apart in order to further reduce symptoms. Epidural steroid injections can be repeated three or four times a year as necessary to keep symptoms under control and maintain activity levels.

Physical therapy can be beneficial in the treatment of spinal stenosis. It is most successful in combination with epidural steroid injections but can be tried alone prior to initiating interventional care. Physical therapy focuses on opening the neurovascular spaces and reducing the stenosis. This is accomplished by initiating a flexibility program to improve hip mobility, flexion based stabilization exercises for the lumbar spine, strengthening of the muscles that support the spine, strengthening of the muscles of the lower extremities, manual therapies to relieve muscle spasm and muscle shortening, and cardiovascular exercise. Furthermore, education regarding posture and correct body mechanics with lifting, bending, pushing, and pulling may be beneficial. Finally, physical therapy can assist the patient with spinal stenosis to identify their walking and lifting limits in order to reduce aggravation of the symptoms.

Another conservative measure that may be used for treating symptoms associated with spinal stenosis is pain medication. There is a wide range of medication that may be prescribed by a healthcare provider that can be beneficial. Usually, treatment is started with Tylenol or anti-inflammatory medications like ibuprofen or naproxen. If these medications are ineffective, stronger opiate based pain medications may be tried. However, these stronger medications are helpful for short-term or intermittent use and are not considered a viable long-term solution for symptom control. Finally, neuropathic pain medications may be beneficial in the treatment of spinal stenosis. These medications may be prescribed alone or in combination with other types of medications. Neuropathic pain medications help to reduce the transmission of pain and paresthesias through nervous system tissue. Long-term use of these medications is safe under the direction and monitoring of a healthcare provider and may be required for aid in symptom control.

The final treatment of spinal stenosis is surgical intervention. This may consist of decompression of the stenotic areas and possible fusion. Surgery is reserved for patients who suffer from severe symptoms who have failed to respond to all other treatments, and/or those who have progressive loss of strength in the legs or changes in bowel or bladder function.

Spinal stenosis is the leading cause of low back and leg pain in people over the age of 60. A variety of treatments are available to those who suffer from spinal stenosis that can significantly reduce symptoms and improve activity levels. The first step toward relief is evaluation by a medical provider with a comprehensive knowledge of the disease process and available treatments.

SIDEBAR:
Common symptoms of spinal stenosis
• Low back pain and/or leg pain with walking or standing
• Feeling of numbness, heaviness, or fatigue in the legs with activity
• Alleviation of pain with short periods of rest (sitting, reclining)
• Improvement in symptoms with leaning forward, squatting, or leaning on shopping cart
• Ability to walk uphill more easily than downhill
• Difficulty climbing stairs