Spinal stenosis is a narrowing of the open spaces within your spine, which can put pressure on your spinal cord and the nerves that travel through the spine. Spinal stenosis occurs most often in the neck and lower back. While some people have no signs or symptoms, spinal stenosis can cause pain, numbness, muscle weakness, and problems with bladder or bowel function. Spinal stenosis is most commonly caused by wear-and-tear changes in the spine related to aging. In severe cases of spinal stenosis, doctors may recommend surgery to create additional space for the spinal cord or nerves.
Why it Occurs
While some people are born with a small spinal canal, most spinal stenosis occurs when something happens to reduce the amount of space available within the spine. Causes of spinal stenosis may include:
• Overgrowth of bone. Wear and tear on your spinal bones can prompt the formation of bone spurs, which can grow into the spinal canal. Paget’s disease, a bone disease that usually affects adults, also can cause bone overgrowth in the spine.
• Herniated disks. The soft cushions that act as shock absorbers between your vertebrae tend to dry out with age. Cracks in a disk’s exterior may allow some of the soft inner material to escape and press on the spinal cord or nerves.
• Thickened ligaments. The tough cords that help hold the bones of your spine together can become stiff and thick over time. These thicker ligaments can bulge into the spinal canal.
• Tumors. Abnormal growths can form inside the spinal cord, within the membranes that cover the spinal cord or in the space between the spinal cord and vertebrae.
• Spinal injuries. Car accidents and other major trauma can cause dislocations or fractures of one or more vertebrae. Displaced bone from a spinal fracture may damage the contents of the spinal canal. Swelling of adjacent tissue immediately following back surgery also can put pressure on the spinal cord or nerves.
Many people have evidence of spinal stenosis on X-rays, but have no signs or symptoms. When symptoms do occur, they often start gradually and worsen over time. Symptoms vary, depending on the location of the stenosis:
• In the neck. Narrowing in the upper (cervical) spine can cause numbness, weakness or tingling in a leg, foot, arm or hand. In severe cases, nerves to the bladder or bowel may be affected, leading to incontinence.
• In the lower back. Compressed nerves in your lower (lumbar) spine can cause pain or cramping in your legs when you stand for long periods of time or when you walk. The discomfort usually eases when you bend forward or sit down.
The type of treatment you receive for spinal stenosis may vary, depending on the location of the stenosis and the severity of your signs and symptoms.
To control pain associated with spinal stenosis, your doctor may prescribe:
• NSAIDs. Nonsteroidal anti-inflammatory drugs (NSAIDs) help relieve pain and reduce inflammation. Some NSAIDs, such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve), are available without prescription.
• Muscle relaxants. Medications such as cyclobenzaprine (Amrix, Flexeril) can calm the muscle spasms that sometimes occur with spinal stenosis.
• Antidepressants. Nightly doses of tricyclic antidepressants, such as amitriptyline, can help ease chronic pain.
• Anti-seizure drugs. Some anti-seizure drugs, such as gabapentin (Neurontin, Gralise) and pregabalin (Lyrica), are used to reduce pain caused by damaged nerves.
• Opioids. Drugs such as oxycodone (Oxycontin, Percocet, others) and hydrocodone (Lortab, Vicodin, others) contain substances related to codeine and can be habit-forming.
A physical therapist can teach you exercises that may help:
• Build up your strength and endurance
• Maintain the flexibility and stability of your spine
• Improve your balance
Your nerve roots may become irritated and swollen at the spots where they are being pinched. Injecting a corticosteroid into the space around that constriction can help reduce the inflammation and relieve some of the pressure. However, repeated steroid injections can weaken nearby bones and connective tissue, so only a few injections a year are allowed.
Surgery may be considered if:
• More conservative treatments haven’t helped
• You’re disabled by your symptoms
• You’re in good health otherwise
The goal is to relieve the pressure on your spinal cord or nerve roots. For example, a mild® procedure can remove part of the thickened ligament and create space to allow blood flow to the spine. In the mild® procedure a very small incision is used and recovery is in hours. In a more invasive procedure called a laminectomy removal of the back part (lamina) of the affected vertebra to create more room within the spinal canal. In some cases, vertebrae also may need to be fused together to maintain the spine’s strength.
In most cases, surgery helps reduce spinal stenosis symptoms. But some people’s symptoms stay the same or get worse after surgery. Surgical risks include infection, a tear in the membrane that covers the spinal cord, a blood clot in a leg vein and neurological deterioration.