What is Craniocervical Instability or CCI?
Cervical refers to the neck and instability that a joint or spinal segment moves around too much (1). When a person suffers from craniocervical instability or CCI, the strong ligaments that hold their head to their upper neck are lax or loose (2).
These ligaments include the alar, transverse, accessory, apical dens, and others outlined in the image below:
Every joint in your body has ligaments that constrain its movement. When a ligament is stretched out or torn, that joint moves too much in the wrong directions (instability), and that can wreak havoc on the joint and cause arthritis.
What Causes Craniocervical Instability?
The neck has seven different numbered spinal levels from C0 (skull) to C7 (base of the neck), and all of these have ligaments and other structures that keep them stable. The two biggest causes of instability are naturally loose ligaments and trauma.
Several congenital diseases can lead to loose ligaments; Ehlers Danlos Syndrome, or EDS, is the most commonly diagnosed one. People with EDS produce too much of a specific type of collagen, which causes the ligaments to be too stretchy. CCI is much more common in these patients, especially as they age (13).
Another cause of craniocervical instability is trauma (3). These patients generally have normal ligaments, but trauma in an EDS patient can double the risk of developing CCI. Causes of trauma can include a car crash, a hit on the head, falling on the head, and manipulating the neck.Request a Regenexx Appointment
What are the Symptoms of CCI?
The symptoms of CCI include headaches, usually upper neck pain near the skull, dizziness or imbalance, visual disturbances, brain fog, rapid heart rate, and others. Let’s take each of these:
- Headaches can be caused by a number of things including upper neck joints like C0-C1, C1-C2, or C2-C3 that get injured or arthritic, irritated occipital nerves at the back of the skull, irritated spinal or cranial nerves, (5,6), or tendons pulling on the covering of the brain (7).
- Upper neck pain near the skull is usually caused by the upper neck joints, muscles, and tendons in this area getting beat up by the instability.
- Dizziness or imbalance is a feature related to the fact that the upper neck is a major contributor to balance (4). The upper neck provides position sense that has to be coordinated with balance information from the eyes and inner ear.
- Visual disturbances can happen because the upper neck supplies information to the brain to guide eye position and vice versa (9).
- Brain fog is something that has long been reported in patients with upper neck disorders and may be linked to the Barre-Lieou Syndrome (8) which involves irritation of the upper neck arteries or sympathetic nerves. A brain injury also needs to be ruled out if the patient was hit on the head.
- Rapid heart rate can happen as the vagus nerve gets irritated by the extra motion where the skull meets the neck.
Diagnosing Craniocervical Instability
First, patients with craniocervical instability usually fall into two categories. The minority of patients have a huge dislocation of one of the upper neck bones that is often diagnosed on x-ray, CT Scan, or MRI (10). This type of CCI is easier to diagnose, hence it’s usually picked up early. However, the majority of patients with this problem have some or all of the symptoms above, don’t have a seriously dislocated bone, and often struggle to get a diagnosis for months or years.
The patients who have symptoms without severely dislocated upper neck bones usually get diagnosed by one of the following types of imaging:
- Specialized neck MRI using a head coil. To learn more, see my video below:
- Upright MRI:
- DMX or movement-based x-rays:
There are also several different measurements that can be used to make the diagnosis that patients may hear about:
- Grabb-Oakes measurement:
- Powers Ratio:
Treatments for CCI
First, as discussed above, most patients with CCI do not have severe dislocations of the upper neck bones that require immediate surgery. When this does happen, this requires immediate surgical fusion (11). Instead, many patients have smaller amounts of instability that can cause severe disability, but can often be managed with:
- Upper cervical low force chiropractic (NUCCA)
- Physical therapy or exercises focused on CCI exercises
- Curve restoration therapy (CBP)
However, if these options don’t work, the next level of treatment based on my experience is cervical ligament injections (12) or upper cervical facet injections. However, when patients don’t respond to this kind of care, the PICL procedure that involves direct injection of the damaged ligaments (alar. transverse, and accessory) with the goal of healing the damage is another option. See my video below for more information:
There are many different surgical fusion options that involve bolting together upper neck bones to each other or the skull. However, in my experience, these procedures have a very high complication rate. Common problems post-surgery that I have noted:
- Eventual arthritis and pain above or below the fusion
- Misplaced screws damaging joints or nerves
- Failure to fuse (to grow bone between a joint)
Having said that, for the right patients, fusion may be the only option once all other less invasive procedures have failed. In addition, in selected patients, it can be life-changing. You can learn more about the PICL treatment for CCI, here.
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