Spondylolisthesis in the neck, or displacement of the cervical vertebrae, is usually a result of traumatic injury or the gradual development of small fractures within the vertebrae. Vertebral slippage is much more common in the lumbar (lower back) region of the spine than in the cervical (neck) region. However, fractures to a small bony segment (known as the pars interarticularis) adjacent to vertebral joints can cause one cervical vertebra to slip out of place on top of another. This can produce symptoms that include neck stiffness, focal pain, radiating pain, tingling, numbness, and muscle weakness in the upper body.
Spondylolisthesis in the neck can affect the upper portions of the central nervous system (CNS). The CNS consists of the brain, the spinal cord, and nerve roots that exit the spinal cord in pairs along the length of the spine. The spinal cord and nerve roots are conduits for motor and sensory messages that travel between the body’s extremities and the brain. If a cervical vertebra slips out of place, the nerve roots located in the neck region can become vulnerable to compression.
Although there are seven cervical vertebrae, there are eight pairs of cervical nerve roots, denoted C1-C8, threaded through the small spaces in between the cervical vertebrae. Each set of cervical nerves is responsible for transmitting a range of signals that trigger voluntary and involuntary responses in the body. Here are the functions associated with each of the eight sets of cervical nerves:
- C1 – breathing, blood supply to the head
- C2 – breathing, head and neck movement, eyesight
- C3 – breathing, facial movement
- C4 – breathing, heart rate, facial movement
- C5 – heart rate, wrist and elbow movement
- C6 – heart rate, neck and shoulder movement
- C7 – arm, hand and finger movement
- C8 – arm, elbow, hand and finger movement
Compression of any of these nerves caused by spondylolisthesis in the neck can interfere with the body’s ability to carry out the function related to that particular nerve. In most cases, cervical nerve compression symptoms – neck pain; headaches; pain that travels into the shoulders, arms, and hands; tingling; numbness; and muscle weakness – can be managed using a regimen of conservative, nonsurgical treatment methods such as medication, exercise, stretching, behavior modification, and others. Neck surgery usually becomes an option only if conservative treatment for neck pain proves ineffective after several weeks or months.