Spinal stenosis refers to the narrowing of the spaces surrounding the spinal cord and nerve roots. When spinal stenosis develops impingement, irritation and inflammation of nerves in the involved vertebrae can occur. A variety of symptoms including pain, tingling, numbness, muscle cramping or weakness may then develop.
The spine is a complex anatomical structure composed of vertebrae. It is designed to provide structural support for the body while allowing flexibility and movement. A hollow space in the vertebrae called the spinal canal houses and protects the spinal cord. Nerves branch off the spinal cord and exit the spinal canal through passageways called the intervertebral foramen. In the presence of spinal stenosis, bony changes or soft tissue problems have narrowed the spinal canal and/or these nerve passageways.
Spinal stenosis can happen anywhere along the spine but is most often seen in the lower back or the neck.
Among the possible causes of spinal stenosis are:
- Degenerative changes associated with aging
- Arthritis: Osteoarthritis and rheumatoid arthritis can both affect the spine
- Congenitally small spinal canal or structural deformities of the vertebrae
- Instability of the spine resulting in vertebral slippage that narrows the spinal canal
- Tumors of the spine
- Spinal trauma due to accidents or injuries
The symptoms of spinal stenosis usually appear slowly and get worse over time. However, there are some cases where the onset of pain may be sudden. Depending upon which part of the spinal canal or nerve root passageway has narrowed will determine where pain and other neurological dysfunction is experienced. In the lumbar area stenosis may cause sciatica with symptoms of pain, tingling, numbness, or weakness running from the buttocks down through the legs. With stenosis in the neck area, symptoms may radiate from the neck down through the shoulders, arms and hands. In the most severe cases, direct pressure on the spinal cord can result in significant symptoms including pain, muscle weakness, difficulty walking or standing, and loss of control of bladder or bowel function.
For mild to moderate symptoms of spinal stenosis, conservative, non-surgical therapy is the first step. Modified activities, medications, physical therapy and exercise might be helpful. In cases of severe pain and disabling symptoms surgery may be indicated.