Most cervical problems are due to degenerative changes that occur in the discs and joints of the neck. Degenerative changes that affect the structures of the spine can cause the spinal canal to become too narrow, a condition called spinal stenosis. This may lead to pressure on the spinal cord. Bone spurs that stick into the spinal canal take up space, making the spinal canal smaller. They can press against the spinal cord or nerve roots.
Pressure on the spinal cord from spinal stenosis can cause symptoms of myelopathy. Myelopathy may impair normal walking, hand and finger use, and bowel and bladder function. Doctors take these symptoms very seriously because severe myelopathy that is not treated may lead to permanent nerve or spinal cord damage. Pressure on nearby nerve roots can cause radiculopathy and may produce pain, weakness, or sensory changes in the area supplied by nerves that go from the cervical spine to the shoulder, arm, or hand.
To best understand cervical spinal stenosis it is helpful to know how wear and tear affects the parts of the spine. This process is called degeneration.
As we age, the disc loses some of its water content and, as a result, some of its shock absorbing ability. The first changes that occur in the disc are tears in the outer ring of the disc, called the annulus. Tears in the annulus may occur without symptoms. You may not notice when they occur or what caused them. These tears heal by forming scar tissue.
Scar tissue is weaker than normal tissue. Repeated injuries and tears cause more wear and tear to the disc. As the disc wears, it gets less and less "spongy", eventually becoming unable to act as a shock absorber.
As the disc continues to wear, it begins to collapse. The space between each vertebra becomes smaller. This collapse affects how the facet joints in the back of the spine "line up." Like any other joint in the body, the change in the way the spine bones fit together causes abnormal pressure on the articular cartilage covering the facet joints. Articular cartilage is a smooth, shiny material that covers the end of the bones in most joints in the body. Over time, this abnormal pressure causes wear and tear arthritis (osteoarthritis) of the facet joints.
Bone spurs may form around the vertebrae and facet joints. Eventually, bone spurs may begin to form. These spurs may begin to press against the spinal cord, leading to the symptoms of myelopathy discussed earlier. Or the spurs can put pressure on the nerves where they leave the spinal canal. This can lead to symptoms of radiculopathy.
The combined effects of the bone spurs, bulging discs, and thickened ligaments place the spinal cord at risk of being squeezed inside the spinal canal.
The symptoms from spinal stenosis depend on whether pressure is affecting the spinal nerve roots or the spinal cord. A "pinched" nerve in the neck (radiculopathy) usually only causes symptoms in the neck and arms. Pressure on the spinal cord (myelopathy) can affect the arms and legs.
Radiculopathy is a condition that can happen from pressure on a spinal nerve root. Commonly thought of as a "pinched nerve," this type of pressure feels different than pressure on the spinal cord. Pressure on an irritated or inflamed nerve root may produce feelings of pins and needles in the area supplied by the nerve root. The pain may feel deep, dull, and achy. Or you may have sharp, shooting pain along the path of the nerve. Muscles controlled by the affected nerve root may also weaken. Muscles controlled by the affected nerve root may also weaken.
Pressure on the spinal cord (myelopathy) is a greater concern, because it can lead to permanent spinal cord damage. Symptoms from myelopathy vary. Feelings of numbness or weakness can affect both arms and both legs. A loss of muscle control in the legs, called spasticity, may cause difficulty walking. "Position sense" may be lost in the arms or legs. This affects the ability to know where your arms or legs are when your eyes are closed. When this occurs it becomes difficult to use the arm and hands and to know where you are placing your feet as you walk. Myelopathy may disturb the normal function of the bowels and bladder.
To make sure of the exact cause of your neck pain, several diagnostic tests can be used. Standard X-rays, taken in the doctor's office, are usually a first step in looking into any neck problem and will give your doctor an idea of whether cervical spinal stenosis exists. These include an oblique (angled) view, along with X-rays taken as you bend forward (flexion) and backward (extension). Your doctor will also determine whether other tests, such as an MRI, are needed.
Conservative treatment options can include epidural steroid injection (ESI), also called a nerve block, and physical therapy.