Causes and symptoms: As people age, shrinkage of the vertebral disks prompts the vertebrae to form osteophytes to stabilize the back bone. However, theposition and alignment of the disks and vertebrae may shift despite the osteophytes. Symptoms may arise from problems with one ormore disks or vertebrae. Osteophyte formation and other changes do not necessarily lead to symptoms, but after age 50, half of the population experiencesoccasional neck pain and stiffness. As disks degenerate, the cervical spine becomes less stable, and the neck is more vulnerable toinjuries, including muscle and ligament strains. Contact between the edges of the vertebrae can also cause pain. In some people, thispain may be referred—that is, perceived as occurring in the head, shoulders, or chest, rather than the neck. Other symptoms may includevertigo (a type of dizziness) or ringing in the ears. The neck pain and stiffness can be intermittent, as can symptoms of radiculopathy. Radiculopathy refers to compression on the base, orroot, of nerves that lead away from the spinal cord. Normally, these nerves fit comfortably through spaces between the vertebrae. Thesespaces are called intervertebral foramina. As the osteophytes form, they can impinge on this area and gradually make the fit between thevertebrae too snug. The poor fit increases the chances that a minor incident, such as overdoing normal activities, may place excess pressure on the nerveroot, sometimes referred to as a pinched nerve. Pressure may also accumulate as a direct consequence of osteophyte formation. Thepressure on the nerve root causes severe shooting pain in the neck, arms, shoulder, and/or upper back, depending on which nerve rootsof the cervical spine are affected. The pain is often aggravated by movement, but in most cases, symptoms resolve within four to sixweeks. Cervical spondylosis can cause cervical spondylitic myelopathy through stenosis- or osteophyte-related pressure on the spinal cord.Spinal stenosis is a narrowing of the spinal canal—the area through the center of the vertebral column occupied by the spinal cord.Stenosis occurs because of misaligned vertebrae and out-of-place or degenerating disks. The problems created by spondylosis can beexacerbated if a person has a naturally narrow spinal canal. Pressure against the spinal cord can also be created by osteophytes formingon the inner surface of vertebrae and pushing against the spinal cord. Stenosis or osteophytes can compress the spinal cord and its bloodvessels, impeding or choking off needed nutrients to the spinal cord cells; in effect, the cells starve to death. With the death of these cells, the functions that they once performed are impaired. These functions may include conveying sensoryinformation to the brain or transmitting the brain's commands to voluntary muscles. Pain is usually absent, but a person may experienceleg numbness and an inability to make the legs move properly. Other symptoms can include clumsiness and weakness in the hands,stiffness and weakness in the legs, and spontaneous twitches in the legs. A person's ability to walk is affected, and a wide-legged,shuffling gait is sometimes adopted to compensate for the lack of sensation in the legs and the accompanying, realistic fear of falling. Invery few cases, bladder control becomes a problem.