What is Spinal Stenosis?
The spinal column is the part of the human skeleton that protects the spinal cord. Each segment or vertebra of the spinal column forms the spinal canal containing the spinal cord and its nerves. As in any joint of the body degenerative changes can occur between these vertebrae which can lead to osteoarthritis. These degenerative changes may include thickening and calcification of the ligaments surrounding the cord and growth of bony spurs along the spine. These changes result in spinal stenosis which gradually constricts the spinal cord and may lead to its compression. Other medical conditions such as trauma and inflammation can also lead to stenosis, but those related to the aging process are more common.
The lumbar region of the spine is most commonly involved in degenerative changes, although the cervical and thoracic regions may also be affected.
Complications of Spinal Stenosis
Degenerative changes like osteoarthritis develop gradually and may produce symptoms of low back pain when the lumbar spine is involved. Over time, patients may experience stiffness and limitation in motion. They may have pain and irritation during movement of the lower back, especially when standing and leaning backwards, which may be relieved by rest.
As the compression of the spinal cord progresses, complications like numbness and weakness of the lower extremities occur. These are felt especially when standing and walking. Eventually, legs may become paralyzed, a condition called paraplegia, with inability to walk or stand. As the condition progresses, the patient may lose bowel or bladder control.
Spinal stenosis paraplegia is not common, and since weakening of the legs occurs gradually, patients are often diagnosed late. However, spinal stenosis due to arthritic changes is common and can be easily suspected using x-rays which will show degenerative or osteoarthritic changes in the spine. The diagnosis is confirmed by CT scan, myelogram, CT-myelogram and MRI. These imaging tests will show the severity and extent of spinal cord compression.
Treatment of Spinal Stenosis and Paraplegia
Mild to moderate spinal stenosis respond to conservative treatment like anti-inflammatory and pain medications. Muscle relaxants may help in patients who experience spasms, although these should not be used for long periods especially by elderly patients. Other medications that can be used for pain and inflammation are steroids which are injected in the space around the spinal cord. Physical therapy is advised to patients so as to strengthen the muscles and increase mobility of the spine.
When conservative measures fail and spinal stenosis is worsening, surgery has to be done to prevent paraplegia. A procedure called laminectomy is performed when multiple segments of the spine are involved. However, when only one or two levels are constricted, a microscopic laminectomy or intra-laminar decompression may be done. These procedures decompress the spinal cord to prevent deterioration of function and worsening pain. In cases where there is instability or malalignment of the spine, spinal fusion can be done in addition to decompression.
Although these procedures are usually successful in treating early signs of weakness and in preventing paraplegia, patients who are older than 80 years may experience complications related to their general state of health.
USC Center for Spinal Surgery, “Spinal Stenosis”, https://www.uscspine.com/conditions/back-spinal-stenosis.cfm
SpineUniverse, “Spinal Stenosis: Lumbar and Cervical”, https://www.spineuniverse.com/conditions/spinal-stenosis/spinal-stenosis-lumbar-cervical