Spinal stenosis is a narrowing of the spinal canal and occurs most often in people over 50 years of age. As the canal narrows, it puts pressure on the spinal cord and nerves in the canal, causing pain and other symptoms. When the spinal canal narrows in the neck area of your spine, it is called cervical spinal stenosis. In the lower part of your spine, it is known as lumbar spinal stenosis. Symptoms of spinal stenosis develop gradually and worsen over time. Symptoms also vary depending on the area of the spine that is affected.
In the early stages of cervical spinal stenosis (neck area), you may not experience any symptoms even though the condition can be seen on an X-ray. As pressure increases on the spinal cord, you may experience:
- Stiffness, pain or numbness in the neck, shoulders, arms, hands or legs
- Balance and coordination problems, such as shuffling or tripping while walking, as a result of weakness and spasticity in your legs
- Loss of your "position sense," the sensation that allows you to know where your arms and legs are when your eyes are closed
- Incontinence – loss of bowel or bladder control
As pressure from spinal stenosis increases in the lumbar area of your spine (lower back), you may experience:
- Back pain – Depending on the degree of arthritis that has developed, you may or may not have back pain.
- Burning pain in buttocks or legs (sciatica) – Pressure on the spinal nerves can cause pain in the areas where those nerves are reaching and supplying sensation. Lumbar spinal stenosis causes pain that can ultimately reach as far as your foot.
- Numbness or tingling in buttocks or legs – These symptoms can occur as pressure on the nerve increases, and are often accompanied by burning pain.
- Weakness in the legs or "foot drop" – This symptom occurs when nerve pressure reaches a critical level. Foot drop is the feeling that your foot slaps on the ground when you try to walk normally.
- Less pain when leaning forward or sitting – Research studies show that when you lean forward, you can increase the space around the nerves in your spinal column. You may be able to ride a stationary bike or walk leaning on a shopping cart.
The leading cause of spinal stenosis is the process of aging. The wear and tear on the spine over 50 years or more can cause the cushions (discs) between your vertebrae to flatten and bulge. Eventually, the degenerated discs may develop tiny tears in their tough, fibrous outer covering. The tears cause the jelly-like substance in the disc's center to protrude and press on your spinal cord and nerve roots. Also, the tendons (tough, rope-like cords) that hold the spine together can thicken and stiffen over time, narrowing the spinal canal. Together, the degenerative changes of the thickening spinal tendons and the bulging discs can cause spinal stenosis.
Other causes of spinal stenosis are:
- Spinal injuries resulting from motor vehicle accidents and other trauma to the spine
- Genetic disorders such as:
- a narrow spinal canal
- Scoliosis (curvature of the spine)
- Paget's disease of the bone – a condition that causes bones to be deformed or abnormally large. If it happens in the spine, it can cause spinal stenosis.
- Achondroplasia – a condition that slows the rate of bone growth. If it occurs in the spine, babies can be born with spinal stenosis
- Osteoporosis – a condition that thins and weakens bones
- Arthritis in the spine
- Spinal tumors – abnormal growths that may press on the spinal cord and nerve roots
Nonsurgical treatments for spinal stenosis include pain medications, physical therapy and steroid injections. For more severe cases, spine surgery such as cervical laminectomy, lumbar laminectomy, cervical fusion or lumbar fusion may be recommended by your orthopaedist.