The majority of people will experience neck pain at some point in their lives. This can be the result of genetic type degenerative changes and the effects of trauma, sports and occupation. Of these individuals, some will develop cervical central stenosis. This is a condition of the spinal canal where the canal narrows for various reasons and either puts pressure on the spinal cord or places the spinal cord in jeopardy with a fall or impact. This condition is more frequent in the aging population especially by those who are over 50 years of age and have endured wear and tear on the spine.
Many patients who are suffering from cervical central stenosis and myelopathy have experienced trauma in the neck area either through an injury or accident. Sometimes, the symptoms take years to surface as the degenerative process that causes spinal canal narrowing by bone spurs and disc bulging is the hallmark of this disorder. Some individuals have congenital narrowing of the canal. That is- they were born with narrowing and the symptoms can occur earlier in life.
Biomechanics
It is important to know what happens to a spinal canal with neck motion. Bending the head forward causes the spinal canal to enlarge by as much as 30% and conversely, bending the head backwards causes reduction (or narrowing) of as much as 30%. With spinal stenosis, as the spinal canal narrows, there is pressure placed on the spinal cord and it begins to dysfunction- a condition called myelopathy. There are occasions where the cord can be acutely pinched with a forceful blow to the front of the head causing the head to bend violently backwards, a condition called central cord syndrome- a type of spinal cord injury. Please see the section on cord injuries to find out more about central cord syndrome.
Symptoms
The spinal cord is an extension of the lower part of the brain. It is not just a message delivery system but has some important complex processes to keep muscle coordination and bowel/bladder function normal. When the cord is compressed in a condition called cervical stenosis, the spinal cord dysfunctions and myelopathy results.
Myelopathy has been called the great imposter as the symptoms are so unusual that the condition is rarely diagnosed except by a spine specialist. The symptoms start with imbalance with walking. The symptoms can be very subtle in the beginning. Walking in a very dark room (no visual clues) and stumbling can be one of the first signs. Imbalance can extend to the hands. Inability to use the hands for fine motor skills (picking up a dime off a smooth counter, zipping a zipper, difficulty with putting a key into a lock or even a change in handwriting) can be telling. Symptoms can progress to unusual “pins and needles” into the arms or legs, electric like zapping sensations down the back or arms with neck motion (L’hermitte’s sign), bowel and bladder problems and neck pain. Weakness can be noted in the legs.
There are specific signs that occur with myelopathy that are apparent on a careful physical examination and can help confirm the presence of this condition. An MRI of the neck (and occasionally of the thoracic spine) is mandatory if myelopathy is suspected.
Treatment
Non-Surgical
Myelopathy is a condition that is not commonly treated without surgery as it is a continuing injury to the spinal cord and with rare exceptions, surgery is recommended.
Surgical
There are surgical procedures that can help relieve the pressure on the spinal cord or prevent a future injury to the cord. Surgery is designed to relieve pressure and if there are already significant symptoms present, the relief of pressure on the cord should prevent future problems but may not be effective in relieving present symptoms. Surgery can include:
- An anterior fusion (ACDF) can decompress the cord and also create stability to segments that are currently unstable and injuring the spinal cord
- A decompressive laminectomy can be performed to create more space in the spinal canal for the nerves that exist there; this is done by removing the vertebral roof (lamina) and making more space for the cord.
- A posterior laminoplasty can also be performed and is done by lifting the lamina to one side. This expansion helps to open the spinal canal and helps to retain more spinal stability.
This is a side view MRI of severe cervical stenosis and spinal cord compression (note the brighter signal in the spinal cord at the arrow).
This is a picture of atrophy of some hand muscles (the thenar eminence) that commonly accompanies cervical myelopathy. My finger points to the muscle wasting.
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