Rheumatoid Arthritis
Rheumatoid arthritis is a disease that affects all of the synovial joints in the body. The cervical spine contains synovial joints. The destruction caused by the rheumatoid disease process affects different regions of the cervical spine. For the patient with rheumatoid arthritis, the effects of the arthritis on the cervical spine can vary from minimal symptoms to life threatening pressure on the spinal cord that requires complex surgery to stabilize the spine and reduce the pressure on the spinal cord.
Causes
Rheumatoid arthritis is a disease that causes destruction of synovial joints. The problems that arise in the neck are primarily due to this destruction of the synovial joints. As the joints are destroyed, the connection between each vertebra becomes unstable. The upper vertebra is able to slide forward on top of the one below. This slippage is called spondylolisthesis. In the lower part of the neck below C2 this can lead to pressure on the nerve roots and the spinal cord.
This problem of instability is most dramatic between the C1 and C2 vertebrae. As the facet joints and the ligaments that hold the odontoid firmly in the front of the ring formed by the C1 vertebra are destroyed, the C1 vertebra is able to slide forward. If this instability becomes too great the odontoid may start to push into the spinal cord. This can lead to problems from too much pressure on the spinal cord.
The connection between the skull and the C1 vertebra may become unstable as well. The destruction of the joints between the skull and the C1 vertebra allows the skull to “settle.” When this occurs the bony knob of the C2 vertebra (the odontoid) begins to move upward into the skull and can put pressure on the spinal cord as it leaves the skull through an opening called the foramen magnum. The two vertebral arteries also enter the skull through this opening and may also be compressed by the odontoid.
Symptoms
The symptoms of rheumatoid arthritis in the cervical spine are extremely varied. Pain is the earliest symptom and may be part of the overall joint inflammation that occurs with the arthritis. As the disease progresses, the symptoms that are most worrisome are those that suggest that the spinal cord is being affected.
Pain at the base of the skull is common and can indicate that the nerves that exit the skull and the upper spine are being irritated or compressed. Pressure on the vertebral arteries can lead to blackout spells when the blood flow through these arteries is diminished with certain movements of the head and neck.
Diagnosis
An important part of evaluating the neck includes X-ray of the cervical spine. This may include special X-rays where you are asked to bend your head forward as far as possible and back as far as possible. These are called flexion and extension X-rays and can show how much instability is present between the vertebrae of the neck.
The MRI scan is the most important test for showing the nerves and soft tissues of the cervical spine. This test uses magnetic waves to create slices through the spine. Using this test, the degree of compression on the spinal cord can be assessed more accurately than with X-rays alone.
Finally, special electrical tests may be ordered by your doctor and performed by a neurologist. These tests are useful to determine how the spinal cord is functioning.
Treatment
The primary nonsurgical treatment of the cervical spine problems associated with rheumatoid arthritis begins with good medical control of the rheumatoid arthritis. This treatment is normally managed by a specialist in rheumatology rather than the spine surgeon. Within the past several years, there have been significant advances in the development of new medications that can control the destructive effects of the arthritis on the joints. Your rheumatologist will manage these medications.
When signs of pressure on the spinal cord become apparent, your neurosurgeons might feel that surgical stabilization should be considered. The goal of surgery is to stabilize the unstable portion of the cervical spine, to remove pressure from the spinal cord and to relieve the pain caused by the underlying instability. The most common procedure for this condition is a cervical fusion.