What is spinal stenosis?
Spinal stenosis is a degenerative condition that happens gradually over time and refers to:
- Narrowing of the spinal and nerve root canals
- Enlargement of the facet joints
- Thickening and stiffening of the ligaments
- Overgrowth of bone and bone spurs
Stenosis can occur along any area of the spine (cervical, thoracic, lumbar), but is most common in the lumbar area. Nearly every adult’s spinal canal narrows with age; however, for most people this does not cause symptoms. Narrowing of the nerve root canal (lateral stenosis) presses on the spinal nerves, causing inflammation and pain. Narrowing of the spinal canal (central stenosis) presses on the spinal cord causing inflammation and weakness.
What are the symptoms?
Symptoms usually develop over time or may occur as a sudden onset of pain. You may feel a dull ache or sometimes sharp and severe pain in different areas depending on which part of the spinal canal has narrowed. The pain may come and go or only occur during certain activities, like walking.
Lumbar stenosis may cause pain as well as tingling or numbness that starts in the buttocks and radiates down the back of both thighs and sometimes into the calves, called sciatica. Stenosis also causes neurogenic claudication, a cramping pain and weakness in the legs, typically the calves, that occurs with walking or standing and goes away with sitting and rest. Over time the symptoms increase, reducing one’s physical endurance. Leaning over a supporting object, such as a walker or shopping cart, can help reduce the pain when walking.
Leg pain and cramping can also be a sign of vascular claudication, which occurs when there’s a narrowing of the arteries in the leg caused by peripheral artery disease. Pain occurs because your leg muscles are not getting enough blood. It’s important that the doctor determine if your leg symptoms are caused by peripheral artery disease or lumbar stenosis. A key difference is that vascular claudication is worse when walking uphill and is not relieved by bending forward.
Cervical stenosis may cause pain as well as tingling or numbness that radiates from the neck, down the shoulders and into the arms and hands. Pressure on the spinal cord, as it runs through the cervical spine, can cause weakness and spasticity in the arms and legs, called cervical spondylotic myelopathy. Spasticity means you lose control over your muscles and have difficulty walking, placing your feet, or dropping objects. You may have trouble with balance and coordination such as shuffling or tripping while walking.
If you experience extreme leg weakness (foot drop) or difficulty controlling your bladder or bowel function, seek medical help immediately. This is a sign of cauda equina syndrome.
What are the causes?
As you get older, your bones undergo degenerative changes that are part of the natural aging process. Osteoarthritis is the most common cause of spinal stenosis. The cushioning disc between your vertebrae dries out and shrinks. You lose bone mass. Bone spurs develop. Your facet joints can enlarge because of strain and stress. This is the body’s attempt to spread stress over a larger area. The larger a facet joint becomes, the less space is available for the spinal nerve as it exits the nerve root canal.
Stenosis can also be caused by other degenerative conditions such as spondylosis or spondylolisthesis; traumatic injury, vertebral fracture, and dislocation; skeletal conditions such as rheumatoid arthritis or ankylosing spondylitis; or metabolic conditions such as Paget’s disease or fluorosis, an excessive level of fluoride in the body.
Who is affected?
Stenosis affects both men and women and is most common between the ages of 50 and 70. It also may occur in younger people who are born with a narrow spinal canal or who experience an injury to the spine.
How is a diagnosis made?
When you first experience pain, consult your family doctor. Your doctor will take a complete medical history to understand your symptoms, any prior injuries or conditions, and determine whether any lifestyle habits are causing the pain. Next a physical exam is performed to determine the source of the pain and test for any muscle weakness or numbness.
Your doctor may order one or more of the following imaging studies: X-ray, MRI scan, myelogram, CT scan, or Doppler ultrasound. Based on the results, you may be referred to a neurologist, orthopaedist, or neurosurgeon for treatment.
- Computed Tomography (CT) scan is a safe, noninvasive test that uses an X-ray beam and a computer to make 2-dimensional images of your spine. It may or may not be performed with a dye (contrast agent) injected into your bloodstream. It is especially useful for viewing changes in bony structures.
- Magnetic resonance imaging (MRI) scan is a noninvasive test that uses a magnetic field and radiofrequency waves to give a detailed view of the soft tissues of your spine. Unlike an X-ray, nerves and discs are clearly visible. It may or may not be performed with a dye (contrast agent) injected into your bloodstream. MRI is useful in evaluating soft tissue damage to the ligaments and discs and assessing spinal cord injury.
- Doppler ultrasound is a noninvasive test that uses reflected sound waves to evaluate blood as it flows through a blood vessel. This test may be performed to rule out peripheral artery disease as a cause of painful leg symptoms.
- Myelogram is a specialized X-ray where dye is injected into the spinal canal through a spinal tap. An X-ray fluoroscope then records the images formed by the dye. Myelograms can show a nerve being pinched by a herniated disc, bony overgrowth, spinal cord tumors, and spinal abscesses. The dye used in a myelogram shows up white on the X-ray, allowing the physician to view the spinal cord and canal in detail. A CT scan may follow this test.
What treatments are available?
There are no medications or treatments that stop or cure spinal stenosis. Conservative, nonsurgical treatment is the first step to controlling mild to moderate symptoms of spinal stenosis. However, if you have severe disabling pain and significant difficulty walking, your doctor may recommend surgery.
Nonsurgical treatments:
Self care: Using correct posture and keeping your spine in alignment are the most important things you can do for your back. The lower back (lumbar curve) bears most of your weight, so proper alignment of this section can prevent injury to your vertebrae, discs, and other portions of your spine. You may need to make adjustments to your daily standing, sitting, and sleeping habits. You may also need to learn proper ways to lift and bend. You may be able to slow down the progression of stenosis by not smoking and maintain a weight that’s appropriate for your height and body frame.
Physical therapy: The goal of physical therapy is to help you return to full activity as soon as possible. Physical therapists can instruct you on proper posture, lifting, and walking techniques, and they’ll work with you to strengthen your back, leg, and stomach muscles. They’ll also encourage you to stretch and increase the flexibility of your spine and legs. Exercise and strengthening exercises are key elements to your treatment and should become part of your life-long fitness. Check with your doctor before you begin any new exercise program.
Medication:
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, naproxen (Aleve, Naprosyn), and ibuprofen (Motrin, Nuprin, Advil) are used to reduce inflammation and relieve pain.
- Analgesics, such as acetaminophen (Tylenol), can relieve pain but don’t have the anti-inflammatory effects of NSAIDs. Long-term use of analgesics and NSAIDs may cause stomach ulcers as well as kidney and liver problems.
- Steroids can be prescribed to reduce the swelling and inflammation of the nerves. They are taken orally (as a Medrol dose pack) in a tapering dosage over a 5-day period. They have the advantage of providing pain relief within a 24-hour period.
Steroid injections: This minimally invasive procedure is performed with x-ray guidance and involves an injection of corticosteroids and a numbing agent into the spine. The medicine is delivered right into the painful area to reduce the swelling and inflammation of the nerves. Repeat injections may be given to achieve full effect. Duration of pain relief varies, lasting for weeks or years. Injections are done in conjunction with a physical therapy and/or home exercise program to strengthen the back muscles and prevent future pain episodes.
- Epidural steroid injections: An injection of corticosteroid is delivered into the epidural space of the spinal canal or nerve root canals to reduce the swelling of the spinal nerves.
- Face injections: An injection of corticosteroid is delivered directly into the painful facet joint.
Chiropractic manipulation: Spinal adjustment is a treatment that applies pressure to an area to align the bones and return joints to more normal motion. Good motion helps reduce pain, muscle spasms or tightness, and improves nervous system function and overall health. Motion also reduces the formation of scar tissue, which can lead to stiffness.
Holistic therapies: Some patients find acupuncture, acupressure, yoga, nutrition/diet changes, meditation and biofeedback helpful in managing pain as well as improve overall health.
Surgical treatments:
Surgery for spinal stenosis involves removal of the bony overgrowth to relieve pressure and pinching of the spinal nerves. Another goal of surgery is to stop painful motion of an unstable spinal segment.
Spinal decompression (laminectomy): An incision is made in the middle of the back. The spinal muscles are moved aside to expose the bony vertebra. The arched portion of the vertebra, called the lamina, is removed (laminectomy) to expose the spinal cord and nerves. Thickened ligaments and bone spurs are removed. The overgrown facet joints, located directly over the nerve roots, may be trimmed to give more room for the spinal nerves to exit the spinal canal. If there is a herniated disc, a discectomy may be performed. In patients with severe symptoms of lumbar spinal stenosis, decompression surgery along is effect approximately 80% of the time [1].
Spinal fusion: In patients with stenosis and spinal instability or slippage of one vertebra over another (spondylolisthesis), the surgeon may recommend to permanently join together two or more vertebrae to give your spine more stability. This is usually done at the same time as a laminectomy. Bone grafts, usually from your own hip or from a bone bank, are placed across severe vertebrae where the lamina was removed. Over time (3 to 6 months) the bone graft will fuse the vertebrae into one solid piece of bone. Metal plates and screws may be used to immobilize the area while fusion is created.
Laminoplasty is performed only in the neck (cervical) when multiple levels of the spine are affected by stenosis. It opens up the space within the spinal canal by creating a hinge on the lamina and opening a door to the canal. A metal plate bridges the gap in the opened section.
Interspinous process spacers: are devices that are inserted between the spinous processes – the bony protrusions along the back of the lumbar spine. Once in place, the spacer lifts and opens the spinal canal as if one were in a seated position rather than a standing position, effectively relieving the pressure on the spinal nerves. The spacer device is not attached to bone or ligament and does not result in spinal fusion. The surgery is minimally invasive and can be done under local anesthetic. Because interspinous spacer are relatively new, the long-term effectiveness is not known. Also, not all insurance companies will pay for this technology and out-of-pocket expenses may be incurred.
To schedule an appointment with our spine specialists, please call 515.875.9560.