Spinal Stenosis refers to narrowing (stenosis) of the spinal canal. The spine is made of multiple vertebrae (bone) which are stacked on one another. Between these vertebrae are flexible discs. This structure allows our spine to move in various directions. In the center of the bony spinal column structure is a canal by which nerves from the brain to travel down to the rest of the body. As we age, our discs and bones start to wear away (arthritis). This occurs in everyone and the rate at which this happens can vary depending on many factors. As our discs and bones wear away, the channel for our nerves and spinal cord narrows and eventually the spinal cord or spinal nerves can become pinched or put under significant pressure. This compression will cause symptoms depending on the location in which it occurs. Spinal stenosis most commonly affects the cervical (neck) and lumbar (lower back) regions of the spine. When found in the neck it is called cervical spinal stenosis.
What does spinal stenosis in the neck cause?
Myelopathy is the term used to describe the constellation of neurological symptoms that develop as the result of chronic and progressive spinal cord compression. Myelopathy is most often caused by a combination of disc bulging, osteophyte (“bone spur”) formation and overgrowth of the joints of the spine. A disc osteophyte complex in conjunction with overgrowth of the spinal ligaments (ligamentum flavum) can cause narrowing of the diameter of the spinal canal (stenosis). This mechanical compression can be static or dynamic (worse with motion like neck extension).
In many patients compression of the spinal cord can be asymptomatic, even in the presence of advanced changes seen on an MRI. Since stenosis develops slowly, the body is typically able to accommodate and tolerate these changes. It is the mechanical compression of the spinal cord that results in myelopathy. Once central stenosis has occurred, even minor injuries have the potential to cause an insult to the spinal cord, which can result in an acute and significant neurologic deficit.
Myelopathy may manifest itself as a loss of dexterity in the fingers, loss of balance, or unsteadiness with walking. Specific examples include difficulty with fine motor skills (buttoning clothing or putting on jewelry), a change in handwriting, dropping of objects, or heaviness or weakness in the arms or legs. When stenosis is severe, the symptoms can progress to include a loss of bowel or bladder
function. The physical exam for myelopathy includes testing for hyperactive or abnormal reflexes and muscle weakness.
How do we treat Cervical Myelopathy & Spinal Stenosis?
Cervical myelopathy is a serious problem. The pressure on the spinal cord typically won’t go away without surgery and the symptoms will most likely continue to get worse. If you do not improve rapidly with non-operative care, surgery will be recommended to relieve the pressure on the spinal cord. Surgery is mainly performed to prevent the progression of symptoms. There are several surgical procedures used to treat cervical spinal stenosis and myelopathy. The type of surgery recommended depends on the location and extent of the cervical pathology. However, the overall goal of surgery is to relieve the pressure on the spinal cord by making the spinal canal larger. Myelopathy can be treated by an anterior (from the front) or posterior (from the back) approach.
The choice of the approach depends on factors including the site and degree of cord compression and the number of spinal levels involved. An anterior decompression may be
accomplished by removing the disc (discectomy) or vertebral body (corpectomy) and replacing it with a solid piece of bone graft. Posterior decompression takes the form of a laminectomy in which we remove bone from the back of the spinal column in order to make more room for the spinal cord. With either procedure, a spinal fusion is usually necessary to maintain or restore stability in that portion the spine.