Upper Cervical Instability Following Head Trauma

"Military Neck" showing a loss of normal cervical curvature.

Concussions and traumatic brain injuries often involve a high-impact event that leads to damage not only to the brain, but also the neck.  Healing traumatic neck injuries often involves numerous approaches to resolve muscle spasms, muscle tension, reduce inflammation, and strengthen neck muscles. People can often benefit from head-eye-vestibular neurorehabilitation. In a small percentage of cases however, a person can suffer from a disorder called upper cervical instability that can cause numerous neurological symptoms and requires more specialized assessments and treatment.  

One of the problems people often face when they have cervical instability is a long period of time of suffering before they get a proper diagnosis. Standard MRI imaging of the neck while people are laying down does not provide the right parameters for assessing this specific type of disorder. A lack of agreement on how to screen and test for cervical instability in addition to a general lack of awareness are two main causes for this condition often going undiagnosed.

Upper Cervical Instability falls into a category of hypermobility disorders, where there is too much mobility taking place in a joint, which leads to an unstable condition in that joint. This may be due in-part to underlying generalized hypermobility disorders such as Ehlers Danlos Syndrome that existed prior to the head injury, repetitive whiplash injuries leading to ligament laxity, or as a direct isolated incidence of trauma to the head and neck.  

Other theories that may account for a rising incidence of upper cervical instability following head trauma involves postural changes and ligament laxity that can occur over time as a consequence of our modern lifestyle in which many individuals spend large amounts of time in a forward head face-down posture while staring at phones, tablets, and laptops. While this may seem innocuous, it can lead to a loss of normal cervical curvature, incorrect positioning of the first cervical vertebrae, and encroachment of the carotid sheath containing the vagus nerve and jugular vein. Abnormal stretch on the vagus nerve can elicit symptoms associated with dysautonomia. Compression of the jugular vein can affect fluid dynamics and internal pressure in the head.

When there is too much instability within the upper-most joint of the cervical spine – the atlanto-occipital joint and the joints of the first and second cervical vertebrae - this can lead to a collection of symptoms ranging from mild to debilitating.  Instability within these joints can cause the following:

1. Myelopathy: This is a compression of the spinal cord that can cause a combination of tingling, numbness, and weakness or loss of coordination in the arms.

2. Neuropathy of cranial nerves: This can cause numbness or tingling in the face, mouth, or neck for example.

3. Brainstem compression: The brainstem is where many cranial nerves exit, and where highly sensitive nuclei controlling autonomic functions live.

4. Vertebrobasilar artery compromise: The vertebrobasilar artery supplies blood flow to the brainstem and posterior region of the brain.

5. Cerebrospinal fluid and venous outflow congestion: This can contribute to headaches and a constant sense of head pressure.

Symptoms of Cervical Instability

Due to the above conditions, many of the symptoms of upper cervical instability are neurological symptoms. Here is a list of symptoms people may experience:

·      Headaches or head pressure

·      Neck pain

·      Pain or pulling sensations in the face

·      Tingling or numbness in the face

·      Dizziness

·      Lightheadedness

·      Vertigo

·      Difficulty swallowing or choking

·      Changes in voice strength

·      Nausea

·      Blurry vision, tunnel vision, or visual auras

·      Sleep apnea

·      Cognitive symptoms due to alterations in blood flow

·      Changes in hearing

In addition to these symptoms, many people with upper cervical instability report the sensation that their head feels unsupported, and often have apprehension about putting themselves in a situation where their head is jostled, like riding in a car on a bumpy road. Oftentimes, symptoms are worse when they are upright, or their head is in a specific position, versus laying down. Symptoms can also be relieved when wearing a neck brace. Clicking, grinding, and crunching sounds in the neck are also commonly reported.

A recent research paper by Hauser and colleagues defined four different categories of instability that people generally fall into that was based on 8,000 Dynamic Motion X-rays (DMX) also called Digital Motion X-ray or Dynamic Digital Radiography. This categorization is very helpful in highlighting the nuance of this disorder which is often poorly defined. They are as follows:

1. Severe, generalized/overall instability of the cervical spine often due to underlying hypermobility disorders like Ehlers-Danlos Syndrome (more common in females).

2. Instability either above or below (or both) a surgical fusion or degenerative fusion.

3. Severe upper cervical instability due to traumatic events such as car accidents, whiplash, and head injuries.

4. Loss of normal cervical curvature and anterior position of C1.

Treatment of Cervical Instability

One of the questions that is fair to ask, is why doesn’t this condition heal on its own? Ligaments are a tissue type that does not have great blood supply, and therefore, ligament damage can be very slow to heal. It can also be made worse by repetitive injuries, or repetitive postural insults like we discussed earlier. Prolotherapy, which has been around since the 1930’s, can accelerate the healing of ligaments. Prolotherapy involves the injection of either dextrose, platelet-rich plasma, or other compounds into areas where ligaments attach to bone. This creates an inflammatory response that stimulates the body to repair ligament damage and increase the load bearing capacity and tensile strength of these tissues in the neck.

Postural Restoration and Neck Strengthening

The most important thing is to find a therapist that specialized in upper cervical instability. Postural restoration techniques are applicable when there is a loss of cervical curvature.  Chiropractors that specialize in upper cervical care often have access to specific devices and have programs in place to help people with correcting this loss of curvature. Physical therapists that specialize in cervical instability also provide programs that emphasize healthy posture and neck strengthening.   In rare cases, surgical intervention may be required.

References

Hauser, R. A., Matias, D., & Rawlings, B. (2024). The ligamentous cervical instability etiology of human disease from the forward head-facedown lifestyle: emphasis on obstruction of fluid flow into and out of the brain. Front Neurol, 15, 1430390. doi:10.3389/fneur.2024.1430390

 Katz, E. A., Katz, S. B., & Freeman, M. D. (2023). Non-Surgical Management of Upper Cervical Instability via Improved Cervical Lordosis: A Case Series of Adult Patients. J Clin Med, 12(5). doi:10.3390/jcm12051797

Marchesini, N., Demetriades, A. K., Peul, W. C., Tommasi, N., Zanatta, P., Pinna, G., & Sala, F. (2024). Concomitant trauma of brain and upper cervical spine: lessons in injury patterns and outcomes. Eur J Trauma Emerg Surg, 50(5), 2345-2355. doi:10.1007/s00068-023-02278-w

Russek, L. N., Block, N. P., Byrne, E., Chalela, S., Chan, C., Comerford, M., . . . Hakim, A. (2022). Presentation and physical therapy management of upper cervical instability in patients with symptomatic generalized joint hypermobility: International expert consensus recommendations. Front Med (Lausanne), 9, 1072764. doi:10.3389/fmed.2022.1072764