Cervical spondylosis is degeneration of the disks and vertebrae in the neck, putting pressure on (compressing) the spinal cord in the neck.
Cervical spondylosis usually affects middle-aged and older people. It is the most common cause of spinal cord dysfunction among people older than 55.
As people age, osteoarthritis becomes more common. It causes vertebrae in the neck to degenerate. When bone in the vertebrae attempts to repair itself, it overgrows, producing abnormal outgrowths of bone (spurs) and narrowing the spinal canal in the neck. (The spinal canal is the passageway that runs through the center of the spine and contains the spinal cord.) The disks between vertebrae also degenerate, decreasing the cushioning that otherwise protects the spinal cord. As a result, the spinal cord may be compressed, causing dysfunction. Some people are born with a narrow spinal canal. In them, compression due to spondylosis may be more severe.
Often, the spinal nerve roots (the part of spinal nerves located next to the cord (see Biology of the Nervous System: How the Spine Is Organized) are also compressed.
Occasionally in people with osteoarthritis, flexing the neck causes one vertebra to slip over the vertebra next to it (a disorder called spondylolisthesis). As a result, the spinal canal is suddenly narrowed, and each time the neck moves, the spinal cord is slightly but repeatedly injured.
Symptoms may result from compression of the spinal cord, the spinal nerve roots, or both.
If the spinal cord is compressed, a change in walking is usually the first sign. Leg movements may become jerky (spastic), and walking becomes unsteady. Sensation may be decreased in the feet and hands. The neck may be painful and become less flexible. Reflexes may be increased, sometimes causing muscle spasms, particularly in the legs. Coughing, sneezing, and other movements of the neck may worsen symptoms. Sometimes the hands are affected more than the legs and feet. If severe, compression may impair bladder and bowel function.
If spinal nerve roots are compressed, the neck is usually painful, and the pain often radiates to the head, shoulders, or arms. Muscles in one or both arms may become weak and waste away, making the arms limp. Reflexes in the arms may be decreased.
Doctors suspect cervical spondylosis based on symptoms, especially in older people or in people who have osteoarthritis. Magnetic resonance imaging (MRI) or computed tomography (CT) can confirm the diagnosis. MRI provides much more information because it shows the spinal cord and roots. CT does not. However, both procedures show where the spinal canal is narrowed, how compressed the spinal cord is, and which spinal nerve roots may be affected.
Without treatment, symptoms of spinal cord dysfunction due to cervical spondylosis sometimes lessen or stabilize, but they may worsen.
Initially, especially if only nerve roots are compressed, a soft neck collar, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, and muscle relaxants such as methocarbamol may provide relief.
If the spinal cord is compressed, surgery is usually needed. An incision may be made through the front of the neck (anterior cervical fusion) or back of the neck (posterior laminectomy). Part of the affected vertebrae is removed to make more room for the spinal cord. Bone spurs, if present, are removed, and the spine may be stabilized by fusing the vertebrae together. As a rule, surgery does not reverse the existing nerve damage, but it prevents additional nerve damage. The earlier the surgery, the better is the outcome.
Because the spine may be unstable after surgery, people may need to wear a rigid brace to hold the head still while healing occurs.
If muscle spasms occur, baclofen, a muscle relaxant, helps relieve them.
Last full review/revision August 2007 by Michael Rubin, MDCM