When most folks think about rheumatoid arthritis (RA), its the swelling, pain and stiffness in the hands, feet, wrists and ankles that comes to mind. While that all happens, it’s important to recognize that RA encompasses so much more than that in not only the joint realm, but the rest of the body as a whole. You’ll hear me make this statement often:
“Rheumatoid arthritis should just be called rheumatoid disease, a systemic disease that likes to go after the small joints.”
It’s important to make this distinction because it can effect any organ system in the body and any joint. ANY JOINT.
I’ve seen patients with no involvement of the hands or feet and one shoulder, or two elbows, or one knee, or their spine. Anything goes. Common things occur commonly and we certainly expect the small joint involvement, but being a little more open means we’re less likely to miss what’s going on, particularly when the way it presents is atypical.
Today we’re going to zoom in on the involvement of a set of joints outside of the typical small joint involvement. That is the cervical spine or your neck. While not very much a stranger to RA, an assessment of the neck is sometimes left out!
How common is it?
Cervical spine involvement occurs in anywhere from 20-90% of patients studied. I know, wildly variable statistics, but that’s the way it is. Even if we’re conservative here, 1 in 5 cases is still a lot of people. And this really matters, because the complications which we’ll get into can be pretty devastating.
Similar to the involvement of other joints, you have the immunologic activity causing the formation of what we call a pannus local to the involved joints, which you can sort of think of as a little factory that produces enzymes that degrade surrounding tissue. This degradation is what we refer to as erosive change that results in joint deformity. In the neck it contributes to three major categories of instability which we’ll briefly visit below.
The different flavors
This is the most common form of cervical involvement.
This is basically instability at the two uppermost vertebrae in your cervical chain. The top vertebrae, or C1 we call the atlas. The vertebrae just below it, or C2 we call the axis. There’s a very intricate set of ligaments which connect and house these two bones whilst allowing for clean movement of your neck.
Rheumatoid disease tends to effect two ligaments called the transverse and alar ligaments that keep C1 and C2 together. In severe cases, these ligaments become lax enough or completely rupture, allowing movement of C1 into the space that houses your spinal cord, which can cause cord compression. Not good.
This occurs in the cervical spine below the level of C2. Most frequently C2-C3 and C3-C4 are involved. Subaxial changes tend to occur because of involvement the facet joints and intervertebral disks. This form of involvement is the least common.
The other two are definitely bad news, but this one is really bad. You have a structure unique to the C2 vetebrae called the dens allows for rotation of the atlas and skull. It sits just under a large opening in the bottom of your skull that your spinal cord enters called the foramen magnum.
With severe forms of rheumatoid cervical spine involvement, the erosive changes that effect C1 and C2 will actually cause the skull to shift downward onto the dens, which will move into the foramen magnum pressing on the brainstem. There’s an invisible boundary we call McGregor’s line which we highlight on imaging studies to assess how far the dens has encroached the foramen magnum. When the dens has moved 9mm and 8mm past this line in men and women, respectively, impaction of the brainstem is likely present.
What do the symptoms look like?
Aside from the obvious and probable pain and stiffness in the neck, you can have incredibly vague and seemingly unrelated issues because of obstructed blood flow to the brain, which include:
- Change in mental status
- Los of conciousness
- Visual changes and vision loss
- Hearing loss and ringing in the ears
- Balance and gait disturbance
- Difficulty speaking
- Difficulty swallowing
- Drop attacks and sudden severe onset of weakness
- Numbness and tingling
Don’t fly blind
The cervical spine can become involved early along in many cases of RA. The most severe complications of these different manifestations of cervical instability tend to occur over long periods of time. But there are exceptions, particularily if you have more aggressive disease, meaning that erosive changes in the cervical spine can occur very quickly. That being said, it’s imperative that you have a specialist on board who is assessing the structural integrity of your neck at baseline and is monitoring changes over time with some regularity.
You don’t want to be flying blind on this one. Atlantoaxial impaction, or spinal cord compromise is a serious complication with a higher probability in unchecked disease. And once you have myelopathy secondary to this disease, you have a 50% chance of being toast in one year. That’s because you become incredibly susceptible to a fatal blow from relatively minor insults like whiplash, sudden movements, and falls.
What does medicine do about cervical spine instability in RA?
At all stages of cervical spine involvement, pharmacologic treatment is usually initiated, which consist of steroids, biologic and non biologic DMARDs. Early and aggressive treatment, defined as within the first few years of onset and using all three of the medication categories previously mentioned seem to prevent the complications mentioned above. If you decide to opt out of pharmacologic treatment, you’d best be incredibly invested in making dramatic lifestyle modification.
In addition to that, physiotherapy aimed at strengthening the associated musculature around the spine is crucial.
If you fall into the unfortunate category of having longstanding cervical involvement, conventional treatment does not seem to ward of progression, and surgery is often brought to the table based on your clinical picture and what objective evidence demonstrates.
What does this all means for you – make sure your neck was checked.
One of the questions I usually ask patients with RA is whether or not they’ve have x-rays, surprised to hear that many times they have not had an evaluation of their cervical spine. Not having neck symptoms doesn’t excuse that, since it’s clear imaging can evidence probable instability in patients without symptoms.
Whether you’re carrying a diagnosis of rheumatoid arthritis, some other inflammatory condition effecting joints, or you’re in the process of sorting out new onset of a potential inflammatory athropathy, you should ensure your provider has evaluated your cervical spine.
Explanation of the different types of cervical instabilities secondary to rheumatoid disease, the most common form, management and the effects of conventional treatment.