Cervical Radiculopathy
Cervical radiculopathy, commonly called a "pinched nerve" occurs when a nerve in the neck is compressed or irritated where it branches away from the spinal cord. This may cause pain that radiates into the shoulder, as well as muscle weakness and numbness that travels down the arm and into the hand. Cervical radiculopathy is often caused by "wear and tear" changes that occur in the spine as we age, such as arthritis. In younger people, it is most often caused by a sudden injury that results in a herniated disk. In most cases, cervical radiculopathy responds well to conservative treatment that includes medication and physical therapy.
Anatomy
Your spine is made up of 24 bones, called vertebrae, which are stacked on top of one another. These bones connect to create a canal that protects the spinal cord. The seven small vertebrae that begin at the base of the skull and form the neck comprise the cervical spine.
Other parts of your spine include:
Spinal cord and nerves. These "electrical cables" travel through the spinal canal carrying messages between your brain and muscles. Nerve roots branch out from the spinal cord through openings in the vertebrae (foramen).
Intervertrebral disks. In between your vertebrae are flexible intervertebral disks. They act as shock absorbers when you walk or run. Intervertebral disks are flat and round and about a half inch thick. They are made up of two components:
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Annulus fibrosus. This is the tough, flexible outer ring of the disk.
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Nucleus pulposus. This is the soft, jelly-like center of the disk.
Causes
Cervical radiculopathy most often arises from degenerative changes that occur in the spine as we age or from an injury that causes a herniated, or bulging, intervertebral disk. As the disks in the spine age, they lose height and begin to bulge. They also lose water content, begin to dry out, and become stiffer. This problem causes settling, or collapse, of the disk spaces and loss of disk space height. As the disks lose height, the vertebrae move closer together. The body responds to the collapsed disk by forming more bone —called bone spurs—around the disk to strengthen it. These bone spurs contribute to the stiffening of the spine. They may also narrow the foramen—the small openings on each side of the spinal column where the nerve roots exit—and pinch the nerve root. Degenerative changes in the disks are often called arthritis or spondylosis. These changes are normal and they occur in everyone. In fact, nearly half of all people middle-aged and older have worn disks and pinched nerves that do not cause painful symptoms. It is not known why some patients develop symptoms and others do not.
(Left) Side view of a healthy cervical vertebra and disk. (Right) A disk that has degenerated and collapsed.
A disk herniates when its jelly-like center (nucleus) pushes against its outer ring (annulus). If the disk is very worn or injured, the nucleus may squeeze all the way through. When the herniated disk bulges out toward the spinal canal, it puts pressure on the sensitive nerve root, causing pain and weakness in the area the nerve supplies. A herniated disk often occurs with lifting, pulling, bending, or twisting movements.
Herniated disk (side view and cross section)
Symptoms
In most cases, the pain of cervical radiculopathy starts at the neck and travels down the arm in the area served by the damaged nerve. This pain is usually described as burning or sharp. Certain neck movements—like extending or straining the neck or turning the head—may increase the pain. Other symptoms include:
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Tingling or the feeling of "pins and needles" in the fingers or hand
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Weakness in the muscles of the arm, shoulder, or hand
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Loss of sensation
Some patients report that pain decreases when they place their hands on top of their head. This movement may temporarily relieve pressure on the nerve root.
Non-surgical Treatment
Initial treatment for cervical radiculopathy is non-surgical and include physical therapy for evaluation and treatment. Specific movement based on the examination may reduce pain as well as other strengthening exercises and traction. Other treatment modalities are available based on the PT examination.
Surgical Treatment
If after a period of time nonsurgical treatment does not relieve your symptoms, your doctor may recommend surgery. There are several surgical procedures to treat cervical radiculopathy. The procedure your doctor recommends will depend on many factors, including what symptoms you are experiencing and the location of the involved nerve root.