What Causes a Nerve to be Pinched in my Neck (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 and/or arm, as well as muscle weakness and numbness. 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 disc. In some cases, however, there is no traumatic episode associated with the onset of symptoms. In most cases, cervical radiculopathy responds well to conservative treatment that includes medication and physical therapy.
Your spine is made up of 24 bones, called vertebrae, that 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).
- Intervertebral discs. In between your vertebrae are flexible intervertebral discs. They act as shock absorbers when you walk or run. Intervertebral discs are flat and round and about a half inch thick. They are made up of two components:
- Annulus fibrosus. This is the tough, flexible outer ring of the disc.
- Nucleus pulposus. This is the soft, jelly-like center of the disc.
Causes of Cervical radiculopathy
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 disc.
- Degenerative changes. As the discs 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 disc spaces and loss of disc space height. As the discs lose height, the vertebrae move closer together. The body responds to the collapsed disc by forming more bone—called bone spurs—around the disc 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 discs 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 discs and pinched nerves that do not cause painful symptoms. It is not known why some patients develop symptoms and others do not.
- Herniated disc. A disc herniates when its jelly-like center (nucleus) pushes against its outer ring (annulus). If the disc is very worn or injured, the nucleus may squeeze all the way through. When the herniated disc 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 disc often occurs with lifting, pulling, bending, or twisting movements.