Compression of the brainstem – Atlantoaxial instability and Atlas displacement

Ross Hauser, MD.

Atlantoaxial instability and Atlas displacement are a primary focus of the Hauser Neck Center at Caring Medical Florida. In this article, we will discuss possible bizarre and disabling neurological symptoms that have gone undiagnosed or unresolved and the impact of Atlantoaxial instability and Atlas displacement, and upper cervical instability on the brainstem, nerve, and blood vessel compression including the carotid artery, and the jugular veins.

Atlantoaxial instability is the abnormal, excessive movement of the joint between the atlas (C1) and axis (C2). This junction is unique in the cervical spine as the C1 and C2 are not shaped like cervical vertebrae. They are more flattened to serve as a platform to hold the head up. The bundle of ligaments that support this joint is strong bands that provide strength and stability while allowing the flexibility of head movement and allow unimpeded access (prevention of herniation or “pinch”) of blood vessels, nerves that travel through them to the brain and the spinal cord itself.

A patient will come into our clinic, they will describe a daily, emotional battle with the symptoms of “suspected” or “suspicious” atlantoaxial instability. They will tell us about:

The patient will then relate a long, confusing, frustrating medical history that includes MRIs, CT Scans, Physical therapy, and countless medications.

In some patients, an MRI will reveal that the Atlantoaxial joint between C1-C2 has subluxated or moved out of place. Some of these patients will reveal to us that they have been recommended for cervical fusion surgery. Some patients will tell us that their doctors have recommended waiting on the surgery until “things get really bad.”

“I was just diagnosed with three self-fused vertebrae”

While you wait and undergo therapies that will hopefully alleviate symptoms of pain and loss of function, your neck and body will also take action to compensate for the neck instability. In the cervical spine, the body will always choose stability over motion to protect the adjacent neurovascular structures. What does that mean? The body will respond to uneven and unnatural forces exerted on the vertebral bodies by developing osteophyte (bone spurs) and facet hypertrophy (bone overgrowth at the facet joints), the condition even being called “degenerative instability.” (1)

The body’s response to creating a boney fusion to cervical facet joint osteoarthritis, degenerative disc disease, and ponticulus posticus, while very different conditions illustrate the lengths at which the body will go to protect key blood vessels and nerves from compression by wandering and unstable neck bones.

“I’m worried that my atlas and axis are somehow impeding blood flow to my brain and causing a whole myriad of symptoms.” “My adjustments never hold”

Here is a small compilation of emails that describes the conditions some people are experiencing. The emails have been edited for clarity.

My doctor does not think it is in my neck

“My chiropractor thinks my atlas and axis are anteriorly rotated. My physical therapist thinks my C2 was at some point, stuck in flexion. My doctor sent me for an MRI but only did my brain, not the cervical spine as I was complaining of extreme headaches. I have TMJ issues from teeth grinding but I feel this is connected to my neck instability.”

My adjustments do not hold

“Saw an upper cervical chiropractic who found that the atlas was subluxated and had two adjustments that did not hold. . . Currently, pain in neck, shoulders, and upper back ranges from 1-3/10 but it is the lack of full confidence in neck movement that bothers me.”

“. . . found out about an upper cervical chiropractor, adjustments helped almost instantaneously. However, the downside is that the correction only lasts about a week and then all the old symptoms start coming back until readjustment. Readjusted about every week for the past 9 months or so.”

Article outline:

Part 1: Upper cervical instability and atlantoaxial instability, a problem with many names.

  • Craniocervical instability, craniovertebral junction instability, Central or axial atlantoaxial dislocation, or Atlantoaxial instability can be caused by many factors. It can also be treated in many ways.
  • The condition that is the most perplexing for patients and their doctors to figure out is upper cervical instability.
  • Craniocervical instability, craniovertebral junction instability, Central or axial atlantoaxial dislocation, or Atlantoaxial instability can be caused by many factors. It can also be treated in many ways.
  • C1-C2 Rotatory Subluxation: “this condition often goes undiagnosed, or the diagnosis is delayed and the outcome is worse.”
  • Research: MRI can confuse the issue.
  • The problems of accurate cervical instability diagnosis were noted.
  • When Atlantoaxial instability problems become neurologic-like.
  • When Atlantoaxial instability symptoms extend beyond neck-related.
  • Stability or prevention of the anterior translation of the atlas (the atlas is floating or moving forward of the cervical spine).

Part 2: Atlas displacement c1 forward displacement and misalignment.

  • Atlas misalignment vs atlas displacement.
  • Compression of the jugular veins.
  • The vagus nerve and Atlantoaxial instability.

Part 3: Brain stem compression and cervical spine instability

  • A wandering C1.
  • Cut off blood supply to the brainstem – compression of the vertebral artery.
  • MRI does see that cord compression plays a major role in Cervical spondylotic myelopathy.

Part 4 Understanding the cervical ligaments in Atlantoaxial instability 

  • To fix your Atlantoaxial instability, you need to fix your cervical ligaments. When ligaments are ignored, Occipitoaxial fusion becomes the treatment.

Part 1: Upper cervical instability and atlantoaxial instability, a problem with many names

In the image below the axial canal space for the upper spinal cord and/or brainstem and cerebrospinal fluid is severely compromised when the atlas misaligns.

Many people we see have diagnoses and multiple medical terms to describe what is happening to them. For many, these diagnostic tags may be describing symptoms of a singular problem, upper cervical instability.

Like these people, you may have a diagnosis for:

  • Craniocervical instability or craniovertebral junction instability. As described in one paper: “The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint.” (2) This would be the facet joints of C1-C2.
  • Central or axial atlantoaxial dislocation (CAAD).
  • Dens atlantoaxial instability (DAAI).
  • Cervical neck instability.
  • Atlantoaxial instability.

In the medical literature, atlantoaxial instability generally refers to the connection between the atlas and the dens of the axis, which we refer to as dens atlantoaxial instability (DAAI). This is important because dens atlantoaxial instability is more of a surgical lesion, whereas facet atlantoaxial instability can often be treated by conservative measures such as chiropractic care, physiotherapy, and injections.

The caption of the image below reads: Schematic of upper cervical region from posterior (rear) view, Facet joints of C0-C2 are stabilized by capsular ligaments. It is these ligaments that are primarily strengthened by Prolotherapy injections (explained below) to stabilize the spinal segments.

Facet joints of C0-C2 are stabilized by capsular ligaments

The condition that is the most perplexing for patients and their doctors to figure out is upper cervical instability.

The reasons why this condition goes undiagnosed by traditional medical doctors and healthcare professionals are manifold including:

  • Headaches, even suboccipital and occipital ones, are common innocuous complaints.
  • Medical doctors are not trained to evaluate the upper cervical spine.
  • Static x-ray and MRI analyses often do not show upper cervical pathology.
  • Radiologists who read the x-rays and MRIs emphasize the lower cervical vertebrae and discs in their readings, often not even commenting on the upper two cervical vertebrae.
  • There are invasive procedures to decrease nerve impulses for the occipital and trigeminal nerve such as radiofrequency ablation and microvascular decompression, so these techniques are emphasized for treatment; however, occipital and trigeminal neuralgia are both typically from upper cervical instability.
  • Other common symptoms of upper cervical instability include reduced neck range of motion, neck pain, insomnia, dizziness, lightheadedness, neck pain with movement, preauricular (ear) region pain, ringing in the ear, and vertigo. Again, these are common symptoms for which there are drugs to control the symptoms so upper cervical instability is not in the differential diagnosis.

There is no gold standard for making the diagnosis of upper or lower cervical instability. Let’s start with a 2005 study in the medical journal Physical Therapy (3). Here physical therapists correlated the following symptoms with cervical instability:

  • Intolerance to prolonged static postures.
  • Fatigue and inability to hold head up.
  • Improvement with external support, including hands or collar.
  • Frequent need for self-manipulation.
  • Feelings of instability, shaking, or lack of control.
  • Frequent episodes of acute attacks.
  • Sharp pain, possibly with sudden movements.

As a definitive physical examination diagnostic tool has not been developed, cervical instability will continue to be diagnosed primarily through a combination of clinical findings including history, subjective complaints, and manual examination methods. I would add that when available, the definitive diagnosis is confirmed with some type of motion x-ray or MRI examination of the neck which then is correlated with the person’s symptoms and physical examination. Generally, the diagnosis of upper and lower cervical instability is made on clinical grounds, along with associated signs and symptoms in the upper cervical spine. These include muscle tightness, tension, and tenderness. In the range of motion testing, crepitation or clicking in the neck can be palpated or heard. Some patients have been locked in the neck. Pain is typically worse with movement and better with immobilization or rest. Referral of pain from the upper cervical area to the mastoid, occiput, temporal and frontal areas is common. Tenderness over the suboccipital musculature and spinous process of the axis with palpation are common findings. The general major criteria we use at Caring Medical for diagnosing cervical instability based on patient history includes:

  • Cracking or crepitation with the motion of the neck (heard or felt)
  • Suboccipital headache or tension
  • Chronic neck stiffness
  • Major symptoms relieved by rest or head support
  • Major symptoms aggravated or started with neck and/or head motion
  • Self-manipulation

It can also include these more specific (minor) criteria:

  • History of overzealous chiropractic or osteopathic manipulation
  • Migraines
  • Vertigo
  • Tinnitus
  • Dizziness/lightheadedness
  • Significant trauma to the head or neck
  • Job/lifestyle that involves a significant amount of time in forward head posture

Craniocervical instability, craniovertebral junction instability, Central or axial atlantoaxial dislocation, or Atlantoaxial instability can be caused by many factors. It can also be treated in many ways.

The cervical spine is divided into two parts – the upper and the lower cervical spine. The upper cervical spine contains C0 (the occiput or base of the skull) and C1 and C2 (the atlas and axis, respectively). Instability of the upper cervical spine is commonly referred to as Craniocervical instability or Atlantoaxial instability.

A July 2021 paper from the Mayo Clinic Arizona, Department of Neurological Surgery begins: (4)

“Painful atlantoaxial (C1-2) osteoarthritis has been described over 40 years ago. The condition may cause severe pain symptoms and disability related to unilateral suboccipital pain and, in some cases, occipital neuralgia. One of the greatest challenges with atlantoaxial (C1-2) osteoarthritis is making the diagnosis. Diagnosis is commonly missed or delayed when headaches are treated in isolation or when pain is attributed to subaxial spondylosis.”

Let’s note that occipital neuralgia is coming under more intense observation as previously a 2015 paper (5) reported:

“Atlantoaxial osteoarthritis, either in isolation or in the context of generalized peripheral or spinal arthritis, presents most commonly with neck pain and limitation of cervical rotational range of motion. Occipital neuralgia is only rarely attributed to Atlantoaxial osteoarthritis.”

In the image below:

Craniocervical instability or Atlantoaxial instability can be caused by many factors. Trauma injury, congenital defects (defects from birth), and arthritis. A commonality among these causes is the possibility and extent of cervical ligament damage.

The caption of the image below reads: Subtle findings of upper cervical instability on Cone beam CT scan. This particular patient’s cervical spine is curved but bone spurring is noted from the atlas and axis (displayed by arrows) and a slightly tipped back dens (The odontoid process of the C2 vertebrae) with a clival axle angle of 145° suggesting minimal invagination or upper cervical instability. The clival is a boney part at the base of the skull.

A March 2023 paper in the journal Neurosurgical focus (6) updated previously published materials from the study’s authors. This material had been published over a 12-year period in which cases of central or axial atlantoaxial dislocation (CAAD) caused by or causing craniovertebral musculoskeletal and/or neural alteration(s) were examined.

Study learning points:

  • Over the 12-year period, central or axial atlantoaxial dislocation (CAAD) was diagnosed in 393 patients with craniovertebral junction-related musculoskeletal and neural alterations who underwent atlantoaxial fixation.
  • The major radiological diagnosis was determined  with one or more of the other diagnoses:
    • Chiari formation (367 cases),
    • Syringomyelia with Chiari (306 cases),
    • Idiopathic syringomyelia (12 cases),
      • Symptoms of syringomyelia can include: Worsening weakness in arms and legs, loss of sensitivity to pain down the arms into the hands, and headaches.
    • Type B basilar invagination (147 cases). (Type B basilar invagination occurs without standard evidence of atlantoaxial instability as measured by the space between the odontoid process and the posterior border of the anterior arch of the atlas).
    • Bifid arch of the atlas (9 cases),
    • Assimilation of the atlas (119 cases), (the atlas and occipital bone have fused together).
    • C2-3 fusion (65 cases),
    • Klippel-Feil alteration (4 cases), (abnormal fusion of cervical vertebrae at C2 and C3) and
    • Dorsal kyphoscoliosis (hump or hunchback) (15 cases).

This research found that these patients had good results after atlantoaxial fixation without decompression or bone or soft-tissue resection which supports the concept that atlantoaxial instability has a defining role in the pathogenesis of these problems.

What does all this mean? Simply, if you treat cervical spine instability, you can treat these diagnoses.

C1-C2 Rotatory Subluxation: “this condition often goes undiagnosed, or the diagnosis is delayed and the outcome is worse.”

Researchers in Spain led by the University of Valladolid published a July 2022 study in the journal Diagnostics (7) that sought to help doctors understand
C1-C2 Rotatory Subluxation. Here are some of the learning points and suggestions:

“The atlantoaxial joint C2 (axis) with the anterior arch of C1 (atlas) allows (the neck and head) 50% of cervical lateral rotation. It is responsible for precise and important movements that allow us to perform precise actions, both in normal and working life.

Due to low incidence in adults, this condition often goes undiagnosed, or the diagnosis is delayed . . .with a poor prognosis just because of the late diagnosis and the outcome is worse. The correct approach and treatment of atlantoaxial dislocation requires a careful study of the radiological findings to decide the direction and plane of the dislocation.

In almost a century, surgery techniques have not evolved.

The C1-C2 rotatory subluxation has different and varied etiologies (causes) that determine the therapeutic approach to be followed. Common in all of them is pain, inflammation, torticollis, and in more advanced cases, neurological complications. . . when studying and recognizing the different surgical treatment options, there are numerous techniques available, all of them leading to stabilization. However, there is a relevant fact: the techniques have not evolved at all since they were introduced (starting in 1930) up to the present day and until today.”

As alluded to in the citation above, the structure in the human body most important to be in stable alignment is the atlas. Since the atlas is supported by a sea of ligaments and weighs only 2 ounces, yet “supports” the cranium, which weighs a whopping 10-12 pounds, it is prone to misalignment, causing the myriad of potential symptoms discussed in this article.  Sometimes the atlas is 2-3 inches forward from where it should be due to the breakdown of the cervical curve, thus making its improper positioning responsible for many of the symptoms and syndromes related to cervical instability.

The atlas’s 3-dimensional orientation is so important that multiple branches of chiropractic have been formed to realign its malrotations, including orthospinology, Grostic procedures, atlas orthogonal, the National Upper Cervical Chiropractic Association (NUCCA), and others. The medical literature is filled with case reports and studies to show that improving atlas subluxations will lessen symptoms of high blood pressure, migraine headaches, neck pain, and a host of systemic symptoms and illnesses. There is no bone in the body that is more neurologically protected and the atlas is also the “headquarters” for the vagus nerve.

Research: MRI can confuse the issue.

The most common symptoms or physical or muscular manifestations of Atlanto-axial instability or upper cervical instability are: muscle tension in the neck, headache, weakness in holding the head up, relief of major symptoms with laying down or wearing a cervical collar, and a clicking grinding or popping sensation in the neck. An inability to hold a self or chiropractic cervical adjustment is another sign.

Upper cervical instability, including the occiput-C1 and C1-C2 joints, often goes unnoticed because the diagnosis is difficult to confirm without a motion x-ray or MRI. This is simply because the reliability and validity of joint integrity tests performed upon physical examination as well as radiographic studies are still under debate. The most common tests done on physical examination to try and diagnose ligament damage of the upper cervical spine include the Sharp Purser, Anterior Shear, and cervical distraction with various movements including flexion, rotation, and lateral flexion.

What is generally found on physical examination is muscle guarding, because the patient does not want the clinician to even touch the upper cervical area because of the sensitivity and pain. There is sometimes no correlation between the measure of hypermobility or subluxation of the vertebrae and the presence of clinical or neurological signs and symptoms in mild to moderate instability cases.

The problems of accurate cervical instability diagnosis were noted.

In the study cited above from 2005, physical therapists correlated the following symptoms with cervical instability: intolerance to prolonged static postures, fatigue, and inability to hold head up, improvement in symptoms with external support (collar), frequent need for self-manipulation, feelings of instability, shaking or lack of control of the head, episodes of acute attacks, sharp pain with sudden movements.

A few years later in 2009, a paper published in the Journal of Manual and Manipulative Therapy (8) tried to address the challenges of matching a patient’s symptoms with what appeared on an MRI. The problems of accurate diagnosis were noted:

“Information gathered from the patient history, physical examination, and advanced testing augments the decision-making process and is proposed to improve the probability of diagnostic and prognostic accuracy. However, these findings may provide inconsistent results and can lead to errors in decision-making. The purpose of this study was to examine the relationship between common clinical complaints and specific findings on magnetic resonance imaging (MRI) in patients with chronic neck dysfunction.

  • Forty-five participants (25 female), with an average age of 52, were evaluated by a neurosurgeon for complaints of symptoms related to the cervical spine. All participants answered a subjective questionnaire and received an MRI of the cervical spine.
    • Evidence of spinal cord compression was significantly correlated to anteroposterior canal diameter of less than or equal to 9 mm diminished subarachnoid fluid (Cerebrospinal Fluid in the subarachnoid space) around the cord.
    • The report of loss of dexterity was significantly correlated with the report of lower extremity clumsiness.
  • In this study, no definitive relationships were found between the clinical complaints of neck pain, hand function, or clumsiness and specific MRI findings of spinal cord compression. Further research is needed to investigate the diagnostic utility of subjective complaints and their association with advanced testing.

What we had here in this study was a lack of consistency in the interpretation of what the MRI seemed to suggest and what was wrong with the patients.

Of note was the fact that when there was less fluid around the spinal cord, symptoms could be correlated. The image of less fluid suggested spinal cord compression.

A December 2013 study brings us closer to 2021 by the way that the same problems seen 8 years ago are still problems today. Here is a paper from the journal Physical Therapy. (9)

“Patients with neck pain, headache, torticollis, or neurological signs should be screened carefully for upper cervical spine instability, as these conditions are “red flags” for applying physical therapy interventions. However, little is known about the diagnostic accuracy of upper cervical spine instability tests.”

When Atlantoaxial instability problems become neurologic-like.

There is no gold standard for making the diagnosis of upper or lower cervical instability on the clinical ground so it must be suspected so the right radiographic analysis can be made. A 2017 mini-review paper published in the Journal of Spine (10) offers common guidance on what to look for in patients with suspected upper cervical instability. These are many of the symptoms we see here in our patients and are symptoms you yourself are likely suffering from. Here is what the authors published:

“Diagnosis of Atlanto-axial instability is based upon careful history, a detailed neurological exam, and imaging of the upper cervical spine. The most common clinical features are neck pain and suboccipital headache, with the caveats that headache is present in 50% of patients with EDS (doctors should look for Ehlers-Danlos Syndrome as a possible component of the patient’s challenges) and that moderate pain is a common occurrence for most EDS patients.

There may be symptoms referable to the vertebral artery blood flow, including visual changes, as well as headache associated with the vertebral artery itself. Syncopal (fainting or passing out) and presyncope (the feeling that you are going to faint or pass out) events are frequent.

Other symptoms include dizziness, nausea, sometimes facial pain, dysphagia (difficulty in swallowing), choking, and respiratory issues. There is usually improvement with a neck brace. (Note: Please see our Caring Medical article: Cervical collars – why do they help some people and not others?).

Examination often demonstrates tenderness over C1-C2, altered mechanics of neck rotation, hyperreflexia, dysdiadochokinesia (dysdiadochokinesia is an inability to perform rapid alternative movements – for example, as used to test for dysdiadochokinesia, your ability to tap the palm of one hand with the fingers of the other and then flipping the palm over so the fingers can tap the back of the hand), hypoesthesia (loss of sensation) to pinprick.

What this mini-review reveals are the challenges we see of a neurologic-like nature.

Some of the symptoms described above would be considered neurologic-like in nature. Loss of balance, vision problems, and involuntary muscle spasms to name a few. When you understand that the following nerve or nerve centers run within a few millimeters of the atlas and axis vertebrae it is easier to understand these symptoms as being caused by herniation of compression on these nerves.

  1. C2 nerve root which becomes the greater and lesser occipital nerves.
  2. Glossopharyngeal, vagus, spinal accessory, and hypoglossal, all of which are contained at some point in the carotid sheath.
  3. Superior cervical sympathetic ganglia.
  4. Upper cervical spinal cord (and its connections to the trigeminal nerve).
  5. Brainstem

It is extremely important to understand the key role that the stability and alignment of the atlas and axis have on the proper neurological function of the human body. When there is atlantoaxial instability and/or atlantoaxial subluxation (malalignment) most if not all of the above nerves or nerve centers will not function properly. It is not too much to add that the brain will not function properly either, as the arterial, venous, and cerebrospinal fluid flow would also be affected.

For some who did not have a positive MRI reading for Atlantoaxial joint subluxation, they will tell us that they have been recommended for counseling and for mental illness screening. They have been told it may be “all in your head.”

When Atlantoaxial instability symptoms extend beyond neck-related.

Mechanical stability is the spine’s ability to maintain its alignment and to provide protection to the neural (nerves), vascular (blood), and other structures it encloses during physiological loading (stress on the neck) so that there is no harm to any of these tissues and no symptoms are produced. Clinical ligamentous cervical instability is an inability of the cervical ligaments to maintain individual, adjacent, or global vertebral alignment when subjected to increased forces by various postures, positions, and/or motions that alter bony, soft tissue, and/or neurovascular alignment and function such that symptoms result.

The potential seriousness of clinical ligamentous cervical instability is amplified when one considers that all major neurovascular structures from the body that enter and leave the brain and brainstem, including the autonomic ganglia, do so through the neck. The neck is thus a conduit for fluid and nerve flow that run the body through the brain and brainstem. clinical ligamentous cervical instability can disrupt this fluid and nerve flow, and the neurology results can explain many of the chronic symptoms, disorders, syndromes, and diagnoses that plague people.

It is important to realize that unchecked cervical instability could damage the cervical spinal cord, as with each facedown posture of looking at a cell phone, the vertebrae move anterior, thus narrowing the spinal canal. If it were not for muscle tension and spasm, and other compensatory mechanisms that stop excessive cervical motions from injuring vital neurovascular structures, spinal cord damage could occur. If the ligament injury does not heal and the excess motions and forces continue in the neck, degenerative breakdown of the adjacent vertebral segments occurs in the disc, facet, and uncovertebral joints, as well as the vertebral endplates. (11) This degeneration can be manifested as a clicking, grinding, or popping sensation as the person moves or manipulates their own neck. The motion will eventually be limited as bridging osteophytes occur on the facet joints, along with disc degeneration, ultimately fusing the joint. (12) Unfortunately, this degenerative fusion then causes excessive neck motions to occur in the adjacent vertebral motion segment, increasing its stress and potential for becoming unstable. (13)

What are we seeing in this image?

Normal anatomy versus Chiari malformation of the cerebellum. With the size of the posterior fossa too small, the cerebellar tonsils may herniate through the foramen magnum of the skull into the spinal canal. The tonsils block the flow of cerebrospinal fluid and may cause fluid buildup inside the spinal cord, called a syrinx.

Normal anatomy versus Chiari malformation of the cerebellum. With the size of the posterior fossa too small, the cerebellar tonsils may herniate through the foramen magnum of the skull into the spinal canal. The tonsils block the flow of CSF and may cause fluid buildup inside the spinal cord, called a syrinx. 

Stability or prevention of the anterior translation of the atlas (the atlas is floating or moving forward of the cervical spine)

Stability or prevention of the anterior translation of the atlas (the atlas is floating or moving forward of the cervical spine) is performed by the capsular ligaments posteriorly (in the rear) and the transverse ligament anteriorly (in the front). The transverse ligament connects along the expanse of the anterior arch of the atlas. Capsular ligament injury of C1-C2 results in facet atlantoaxial instability, whereas injury of the transverse and alar ligaments causes dens atlantoaxial instability. Injury to the atlantoaxial capsular ligaments causes a dramatic increase in lateral bending and axial rotation motion (43% and 159%, respectively), whereas transverse ligament disruption significantly increases the anterior atlanto-dens interval. This was demonstrated in a February 2019 paper in the Journal of neurosurgery. Spine, (14) from the University of Utah. In this paper, the researchers examined contradictory evidence regarding the relative contribution of the key stabilizing ligaments of the occipitoatlantal joint.

For a detailed discussion of the many health challenges instability in this portion of the neck can cause please see my article: Symptoms and conditions of Craniocervical and Cervical Instability

The stability of the atlas has one primary weak link, the atlantoaxial capsular ligaments.

The stability of the atlas has one primary weak link; the atlantoaxial capsular ligaments, because they are normally “loose” or “stretched” to allow head rotation. The atlantoaxial joint lies between the very stable atlanto-occipital joints (stabilized because of the large convex occipital condyles and concave superior articular facets of the atlas) and the C2-C3 joints, which are stabilized by its intervertebral disc and a myriad of muscles that connect to the large C2 spinous process. The medial atlantoaxial joint is stabilized by the stronger transverse and alar ligaments (compared to the capsular ligaments). It is the atlantoaxial capsular ligaments that are continuously stretched. Facet atlantoaxial instability is easily seen by motion videography (digital motion x-ray). DMX or digital motion x-ray is a motion x-ray and it is discussed below.

Part 2: Atlas displacement c1 forward displacement and misalignment.

In the image below the caption reads: “Lateral c-spine x-ray showing decent neck curve with atlas displacement. Some people do retain the cervical neck curve but still have a forwardly displaced Atlas is what was compressing this person’s carotid sheath causing numerous conditions and symptoms including increased brain pressure intracranial hypertension

Atlas misalignment vs atlas displacement.

Atlas misalignment means the atlas is off alignment a little, one or two millimeters off of ideal anatomy. Atlas displacement, which is a condition we are seeing more and more, as people do the face down lifestyle, such as looking down at a cell phone 5 – 6 hours a day, eventually the atlas is displaced forward.

One of the main differences between an upper cervical or atlas misalignment versus a forward displacement is that the misalignment can typically be adjusted from any perspective, such as an adjustment from the rear or the front.

Because you can approach this misalignment from different perspectives and make small adjustments you can improve the neck dynamics and open up the spinal canal space take the pressure and compression off the carotid sheath, the vagus nerve, internal jugular vein, relieve pressure on the vertebral artery which traverses around the posterior part of the atlas. We don’t recommend anybody try to self-adjust on their own at home because the atlas is a very important structure and you can make your situation worse.

An atlas that is displaced forward, we see this periodically, the patient is going to a really great clinician but they do not realize that the atlas has been displaced forward and these people are being adjusted from the back forward which is more common. The patient may be laying face down on an adjustment table and then they have their head/neck pushed forward and these people can feel worse. The adjustment is perpetuating the injury over time even though they may get the misalignment corrected, the atlas is still forwardly displaced.

We are going to discuss a patient case. We did a cone beam CT scan (Upright cone beam computed tomography (UCBCT) is a radiographic imaging method for three-dimensional imaging of the bony structures of the head (cranium), neck (cervical spine), and facial bones),  and then adjusted him and then performed another adjustment, and we were able to bring the atlas backward from a frontal adjustment and his symptoms resolved.

If you go to an upper cervical chiropractor and it’s just not helping you may have forward displacement. You can determine this by bilateral X-ray showing the atlas has moved forward.

In the image below:

This is a cone beam CT Scan x-ray image. It shows a ponticle – an enlargement of bone that could cause headaches, migraines, double vision, dizziness, or orofacial (mouth and face) pain.

A patient case:

When your atlas is forwardly displaced you are going to have to do something about it. Cervical curve correction may be a possible treatment, such as ergonomic changes in the office or home so you are not looking down all the time, or changes in sleep position. When there is Cervical spine instability and Atlantoaxial instability caused by cervical neck ligament weakness, then treatment addressing the ligament laxity should be discussed. A great majority of the time when a patient suffers a long-standing forwardly displaced atlas there is cervical instability.

In the patient we are discussing, he had just gotten one adjustment from a really good chiropractor but his case is so unique because his C1 is sliding forward and that’s producing a lot of the symptoms. This goes back to our discussion on atlas forward displacement as opposed to atlas misalignment. He was adjusted in a way that applied force (it was a low-force technique) from behind and pushed the atlas further forward and that’s what made him feel really terrible. He felt worse because the adjustment moved an already vulnerable C1 that goes forward a little bit more forward. We were able to help him by moving the atlas backward very carefully.

Compression of the jugular veins.

A patient’s scans demonstrate compression of the jugular veins. The caption of the image below reads: Upright cone CT scan axial view at the levels of the atlas (C1) showing no space between it and this person’s bilateral styloid bones (shown by the arrows). This person’s jugular veins were getting compressed anteriorly by their elongated styloid bones and posteriorly by their anterior subluxed atlas.

This is the patient’s Cone Beam CT showing improvement in the overall curve after adjustment focused on the subtle backward movement adjustment of the C1 atlas.

This simple backward adjustment took compression off the carotid sheath and its important contents including the common carotid artery, and internal jugular vein.
the vagus nerve, part of the recurrent laryngeal nerve, and the deep cervical lymph nodes.

In this patient’s case, there was no space between the styloid and the lateral mass of the atlas. So we adjusted the atlas and we were able to create just a few millimeters of space that allowed the carotid sheath to have a little bit of room. Right after we did this, the patient reported he was feeling better.

The vagus nerve and Atlantoaxial instability

The vagus nerves are the most important nerves in the body. The vagus nerves are most vulnerable to stretch and traction, but also compression in the cervical region, as they lie in a specific space called the carotid space.

The caption of the image below reads: Carotid sheath compression from ligamentous cervical instability (LCI). This is the primary mechanism by which ligamentous cervical instability causes human illness as it obstructs the primary outflow of the brain causing “brain illness” and interferes with the vagus nerve signal transmission leading to body illness.

Carotid sheath compression from ligamentous cervical instability

The carotid space is a paired space  (on the left and right side of the neck) defined by the carotid sheath, a connective tissue boundary in the neck, that is made by the superficial, middle, and deep layers of the cervical fascia. Extending from the jugular foramen at the skull base to the aortic arch at the thoracic inlet, the carotid space is divided craniocaudally into the supra- and infrahyoid regions. The suprahyoid portion of the carotid space contains the internal carotid artery, the internal jugular vein, cranial nerves 9 through 12, the ansa cervicalis, the sympathetic plexus, and deep cervical lymph nodes.

The anatomical layout of the carotid sheath is shown below. The image caption reads: View looking up showing the position of the atlas and carotid sheath contents to the jugular and carotid foramen. Atlas misalignment, especially displacement anterior can kink the carotid sheath contents, particularly the carotid artery, internal jugular vein, and vagus nerve.

The anatomical layout of the carotid sheath

Below the level of the hyoid, (the bone that supports the back of the tongue) the ansa cervicalis (a loop of the first 3 cervical nerves) and cranial nerves 9, 11, and 12 have exited the carotid sheath in the front, leaving thus only cranial nerve 10. The internal jugular vein and the common carotid artery are also contained within the infrahyoid carotid space. The vagus nerve is thus the only cranial nerve in the infrahyoid carotid space. Typically the vagus nerve lies in the posterior groove between the jugular vein and the carotid artery. In the infrahyoid carotid space, the vagus nerve is between the ansa cervicalis which is embedded in the anterior carotid sheath, and the sympathetic plexus which is posterior.

The carotid sheath contents including the vagus nerve (one on each side) because of its location and length are very vulnerable to tissue strain by deformations or deviations from the normal stable cervical lordotic curve

Why someone can have neck-related symptoms but NOT have neck pain. Part 1: Jugular vein

A summary transcript and explanatory notes of this video are available here: Why someone can have neck-related symptoms but NOT have neck pain. Part 1

Part 3: Brain stem compression and cervical spine instability

For many of the neurologic, vascular, and psychiatric-like problems we see, there is an issue with possible compression of the brainstem / spinal cord. In the illustration below we see clearly that the brainstem and spinal cord slip neatly into the space provided by the proper alignment of the C1-C2 atlas/axis. The key here is a properly aligned C1-C2.

What are we seeing in this image?

As mentioned, in the illustration above we see clearly that the brainstem and spinal cord slip neatly into the space provided by the proper alignment of the C1-C2 atlas/axis. The key here is a properly aligned C1-C2. In the image below we see the right posterior or the rear malrotation of the C2. What this means is that the C2 is rotating to the right below the C1. This rotation shows cervical ligamentous or cervical ligament laxity. The problem is the cervical ligaments are not holding the C2 and C1 in proper alignment with each other.

What are we seeing in this image below? A wandering C1.

The basic understanding that this article is trying to present is that the brainstem and spinal cord slip neatly into the space provided by the proper alignment of the C1-C2 atlas/axis. In the image below we see wandering C1 vertebrae. What this means is that the C1 is moving back and forth in an unnatural motion on the C2 and causing compression to the spinal cord, arteries, veins, and nerves. This image here is the image generated by a digital motion x-ray (DMX).

The cervical spine is interconnected by C0-C7 and as mentioned above, stabilized by different structures. I just noted that the lower cervical vertebrae (C3-C7) are stabilized by the intervertebral discs. A May 2022 paper in the journal World neurosurgery (15) comes to us from combined findings from the Yamaguchi University Graduate School of Medicine in Japan and the University of Toledo in Ohio. In this paper, the importance of the intervertebral discs in maintaining cervical spine stability at C2-C7 is noted.

“Soft tissue cervical spine injury have the possibility of causing cervical segmental instability which can lead to spinal cord injury. There is a lack of certainty in assessing whether soft tissue cervical spine injury is unstable or not. This biomechanical study aimed to investigate the risk factors of soft tissue cervical spine injury.”

The question that is sought answered is, how much does soft tissue injury cause risk for spinal cord compression or injury? In this study, computer models were used to assess the cervical spine ligaments at (C2-C7).

Three soft tissue injury models were simulated at C4-C5: (a) posterior ligament complex (PLC) injury (PLCI), (b) Intervertebral disc with anterior longitudinal ligament injury, and (c) when all the injuries were involved. For the Intervertebral disc and combined posterior ligament complex (PLC) injury, Intervertebral disc with anterior longitudinal ligament injury, models, the range of neck motion increased (more instability) at the injury level in extension (by 101%) and left/right axial rotations (more than 30%) compared to the control model. The Intervertebral disc and Intervertebral disc with anterior longitudinal ligament injury models showed an increase of more than 50% in annular and nucleus stresses at the injury level in extension and left/right rotations compared to the intact model. The posterior ligament complex showed similar stresses as the intact model except for flexion. The facet contact forces of the Intervertebral disc and combined injury models increased by more than 100% compared to other models in all motions. The researchers concluded, “In cervical spine injury, all soft tissues have a key role in stabilizing the cervical spine, but the Intervertebral disc (keeping the disc in place) is the most important component of all.” Keeping the disc in place is the role of the cervical spine ligaments.

MRI does see that cord compression plays a major role in Cervical spondylotic myelopathy

In 2021 a paper published in the medical journal Cureus (16) continued: “Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction. Magnetic resonance imaging (MRI) remains the imaging modality of choice, but its findings are not completely specific for clinically significant Cervical spondylotic myelopathy.  . . (The researchers then suggested) the MRI parameters such as canal and cord size of the cervical spine are an objective reflection of compression on the spinal cord. Correlations observed indicate cord compression that plays a major role in the pathophysiology of cervical spondylotic myelopathy.”

What are we seeing in this image? It is an image of less Cerebrospinal Fluid surrounding the spinal cord. It is an image suggesting spinal cord compression

In the image below we have three cross-sections of an upper cervical spinal cord MRI.

  • The first image or image A is considered normal as a white circle, representing cerebrospinal fluid, which surrounds and protects the spinal cord.
  • In image B we see a partial blockage of the cerebrospinal fluid being suggested by the narrower or diminished white ring posteriorly.
  • In image C we have a complete blockage of the cerebrospinal fluid. The white ring no longer being visible.

Cervical instability can be difficult to diagnose. This is largely due to the low reliability and validity of radiographic studies including functional (motion) radiographs and many clinical examination measures that are still under debate and are rather questionable. Unfortunately, there is often no correlation between the hypermobility or subluxation of the joint, clinical signs or symptoms, or neurological signs or symptoms. Sometimes there are no symptoms at all which further broadens the already very wide spectrum of possible diagnoses for cervical instability. However, this is not the case for those of us who are skilled in recognizing cervical joint instability.

In March 2019, a team of neurosurgeons wrote in the medical journal World Neurosurgery, (17) about cervical instability and osteoarthritis. What they found was the degenerative condition of the cervical spine could result in hypermobility of the atlantoaxial segment (excessive rotation, possible subluxations) and cause overstress in the transverse ligament and the lateral atlantoaxial joints.

The surgeons noted: “These changes explain the pathogenesis of atlantoaxial dislocation and basilar invagination associated with osteoarthritis.”

In other words, the c2 vertebra is moving and causing basilar invagination, (reducing the size of the opening in the skull (the foramen magnum) where the spinal cord passes into the brain. This excessive motion is caused by an overstressing (wear and tear) degeneration of the transverse ligament. This is causing the symptoms we alluded to earlier including balance issues, vision issues, headache, and hearing issues, among others.

In my article, Vertebrobasilar insufficiency, I discuss the complexity and challenges of cervical neck instability treatment which we find fully displayed in the controversies and confusions surrounding the diagnosis of vertebrobasilar insufficiency, also called vertebrobasilar artery insufficiency or Bow Hunter Syndrome. Here patients may suffer from symptoms that include dizziness, fainting, blurred vision, visual and auditory disturbances, flushing, sweating, tearing of the eyes, runny nose, vertigo, numbness and tingling, difficulty swallowing or talking, and drop attacks. Please refer to that article for a review of current research.

In this illustration the vertebral artery is clearly seen weaving its way through C1-C2. If the C1-C2 are moving and hypermobile, they could press on and compress the vertebral artery. This could cause the sensation of lightheadedness and feeling faint.

In this illustration, the vertebral artery is clearly seen weaving its way through C1-C2. If the C1-C2 are moving and hypermobile, they could press on and compress the vertebral artery. This could cause the sensation of lightheadedness and feelings of faintness. This is seen in the x-ray below.

In this x-ray, when the patient looks down, a 6 mm space opens between the C1-c2. When the patient looks up, 0 mm, no space. Everything between those two surfaces is compressed.

In this x-ray, when the patient looks down, a 6 mm space opens between the C1-c2. When the patient looks up, 0 mm, no space. Everything between those two surfaces is compressed.

Video summary: In this video, Ross Hauser MD discusses how upper cervical instability can affect the brain stem.

Before we continue to the video, let’s look at an August 2023 study published in the Clinical neurology and neurosurgery (27). It focuses on how brainstem compression can reduce brain volume. Here is what the researchers wrote:

In recent years, structural and functional reorganization of the brain and changes in brainstem structural connectivity have been shown in patients with degenerative cervical myelopathy (DCM). (The researchers) hypothesized that volume loss in the basal ganglia (responsible mainly for motor control), thalami (information processing center for the brain), and brainstem structures exists and is associated with spinal cord compression severity in patients with degenerative cervical myelopathy.

  • Forty-seven patients with degenerative cervical myelopathy and 25 patients with cervical radiculopathy were evaluated.

The researchers found a statistically significant reduction in the volume of the whole brainstem in the degenerative cervical myelopathy group compared to the cervical radiculopathy group. Additionally, reductions in medulla oblongata, pons and midbrain volumes were found in patients with degenerative cervical myelopathy. Additionally, a trend in the loss of volume of the left putamen (part of the brain involved in motor control and learning) was found. Furthermore, medulla oblongata volume was correlated with spinal cord compression severity and white matter damage in patients with degenerative cervical myelopathy.

In summary the researchers suggested that they could reveal a “reduction in the volume of brainstem structures in patients with degenerative cervical myelopathy compared to patients with radiculopathy. Moreover, (they) found that these changes are associated with cord compression severity.”

In other words, the worse the cord compression, the more loss of brain volume.

Cervical spine instability can have a terrible impact on the quality of life in patients where brain stem compression is occurring

In this section and video summary, we see that cervical spine instability can have a terrible impact on the quality of life in patients where brain stem compression is occurring. This is not a new problem. Neck instability and the symptoms I describe above have been linked together for a long time. In 1998 doctors at the Department of Neurosurgery, University of California, San Francisco reported on a strange case (24) of a 41-year-old woman, post-surgery who had flexion-induced compression (every time she pointed her chin down towards her chest) of the upper cervical spinal cord causing symptoms of brainstem compromise in the absence of radiographic evidence of osseous instability. (Nothing was showing up on MRI and there was no calcification of the soft tissue). Still, the patient experienced postsurgical instability with dynamic compression by the C3 vertebral body, which caused brainstem compromise. The patient was then sent for a more comprehensive second surgery to fix this problem. A little over two years after this second surgery the patient was reported asymptomatic.

The point of this research was to make fellow surgeons aware that following a C3 decompression surgery, with continued patient symptoms and no obvious reason for it, surgeons should look for cervical spine instability causing pressure on the brainstem. The patient in this case study had a subsequent C2 – C6 fusion.

This study is demonstrated to highlight that more than 20 years later, unknown problems of upper cervical instability continue to confuse patients and doctors. The patients we see in our offices still suffer from many of the same problems whether these symptoms resulted post-surgical or they have not had surgery yet without radiological evidence that something is wrong with them.

Video Summary
In this video, Ross Hauser MD discusses how upper cervical instability can affect the brain stem.

As you may be aware, the spinal cord enters the brain through the foramen magnum, the hole in the base of the skull. Once through, the brainstem connects with the brain. This does not always occur. Sometimes, the brainstem does not make it all the way through the foramen magnum. The brainstem may end its journey to the brain in the cervical spine, short of the foramen magnum opening.

This is one reason that the brain stem can be affected by upper cervical instability.

  • Research note: A January 2018 study in the journal Neurosurgical Review (25). Wrote of the “growing recognition of the kyphotic clivo-axial angle (a deformity in the curvature of the neck) as an index of risk of brainstem deformity and craniocervical instability.” They note that the kyphotic clivo-axial angle “is a useful sentinel to alert the radiologist and surgeon to the possibility of brainstem deformity or instability.”
  • In Caring Medical Florida, assessing the curvature of the neck is the main component of our treatment plan and is explained below.

Transcranial Doppler to test blood flow

Video at (1:05) in Caring Medical Florida, we document the blood flow of the vertebral artery with Transcranial Doppler. So our ultrasound machines can measure blood flow to the vertebral artery and then we can move a person through a range of motion to see if the blood supply goes down (is reduced). Please see our article Using Transcranial Doppler & Extracranial Doppler Ultrasound Testing at the Hauser Neck Center for further information and explanations.

We document the blood flow of the vertebral artery with Transcranial Doppler. So our ultrasound machines can measure blood flow to the vertebral artery and then we can move a person through a range of motion to see if the blood supply goes down
We document the blood flow of the vertebral artery with Transcranial Doppler. So our ultrasound machines can measure blood flow to the vertebral artery and then we can move a person through a range of motion to see if the blood supply goes down

(Video at 1:35 ) The lower part of the brainstem is called the medulla oblongata and is where Cranial Nerve X or the Vagus Nerve, Cranial Nerve IX or the glossopharyngeal nerve, Cranial Nerve XI or the spinal accessory nerve, and Cranial Nerve XII or the hypoglossal nerve all originate.

Upper cervical instability, by causing a decrease in neurologic function of the lower part of the brainstem can affect the nerves.

Symptoms may be seen as:

(Video at 2:23 ) A connection to constant nausea

  • Interesting too is that the nausea center is right in the lower part of the brainstem.  It is amazing how many people feel nauseated all the time and nobody can tell what’s causing it. These patients have a history of seeing gastroenterologists and various gastrointestinal doctors and they would have no idea that the cause of this chronic nausea can be upper cervical instability. Please see our article Cervical spine instability as a cause of your digestive disorders for further discussion on this problem.

(Video at 2:45 ) Heart palpitations and arrhythmias

  • What’s kind of interesting to me too is how many of my patients who once they get their upper cervical instability resolved, their heart palpitations and their arrhythmias go away. This is not to say that all heart palpitations and arrhythmias, but the lower part of the brainstem is what controls basically heart rate and blood pressure so somebody who’s having tachycardia all of a sudden and then it goes away and then they go to the cardiologist and they can’t really figure out what it is, it could be that the person is just having upper cervical instability affecting the center in the brainstem that controls heart rate and blood pressure. Please see my article Heart racing, heart rate variability, and high blood pressure. A cervical spine problem?

(Video at 3:35) Respiratory rate

  • The lower part of the brainstem also affects the respiratory rate. There are a lot of people who all of a sudden feel panicky, and on the verge of panic attacks.  They start breathing really hard or they have shortness of breath and they don’t know why. It could be that upper cervical instability is decreasing the function of the brainstem.

The Curve of the Cervical Spine

(Video at 4:05) The cervical curve

The Horrific Progression of Neck Degeneration with Unresolved Cervical Instability. Cervical instability is a progressive disorder causing a normal lordotic curve to end up as an “S” or “Snake” curve with crippling degeneration.
The Horrific Progression of Neck Degeneration with Unresolved Cervical Instability. Cervical instability is a progressive disorder causing a normal lordotic curve to end up as an “S” or “Snake” curve with crippling degeneration.
  • The cervical instability from ligament injury causes the cervical spine curve to change, from a normal “C” curve to the opposite, a reversal of the curve. See the progression illustration below.
  • This curve reversal causes stretching on the spinal cord, the cervical spine, with its now unnatural curve, is yanking and pulling on the brain stem and the whole brain. That traction, or pull on the brain stem, can also affect the brainstem as well have cranial nerve function.
  • To get the brainstem and all the nerves working correctly one has to address and tighten the ligaments in the back of the neck as well as get the cervical curve back to its normal lordotic configuration.

"S" cervical curve. Cervical spine instability from cervical ligaments can cause hypermobility of the cervical vertabrae. This leads to a loss of the natural curve or lordosis and eventual cervical kyphosis and an "S" curve.
“S” cervical curve. Cervical spine instability from cervical ligaments can cause hypermobility of the cervical vertebrae. This leads to a loss of the natural curve or lordosis and eventual cervical kyphosis and an “S” curve.

 

Part 4 Understanding the cervical ligaments in Atlantoaxial instability

Above, we have a picture of the Greek mythological titan Atlas. Atlas was ordered by the king of the Greek gods Zeus, to hold the sky in the heavens (later the earth in the heavens as depicted in the art). The C1 vertebra is therefore aptly named the Atlas as it holds the weight of your head as Atlas in mythology holds “the weight of the world.”

A little bit of pretending helps us understand the role of cervical ligaments in Atlantoaxial instability and how the weight of the world can damage our neck.

  • Let’s pretend the globe in the picture to the left is your head.
  • Atlas’s shoulders and torso are the C1 vertebrae.
  • If we pretend that his arms are the cervical ligaments that hold the globe in place on his shoulders and his legs are the cervical ligaments that hold him to the ground, we can see how damage to the arms and legs can make the earth (your head) fall and tilt and create the health challenges typical of Atlantoaxial instability. The ground we will pretend is the C2 axis vertebrae that the C1 atlas stands on.

If Atlas’s right arm is injured, the weight of the world will fall on the left hand. With this extra burden and stress, the left arm will eventually suffer fatigue, wear, and tear, and weaken. With both arms injured and weakened the earth (your head) will wobble between the right and left arm.

If Atlas’s right leg is injured, he will shift his weight to his left leg. The earth will tilt towards his left leg. With this extra burden and stress, the left leg and left arm will eventually be injured. Atlas himself will wobble and have balance issues.

To fix Atlas’s problems, you need to fix his cervical ligaments. His supporting structures keep the globe steady.

To fix your Atlantoaxial instability, you need to fix your cervical ligaments.
When ligaments are ignored, Occipitoaxial fusion becomes the treatment

Fixing the ligaments is usually not the first choice among more traditional doctors. Fusion surgery is. In the above picture, if we cemented Atlas’s feet to the ground do you think his knees and hips would suffer? When your C1-C2 cervical vertebrae are fused to limit atlantoaxial instability and related symptoms, the force and energy in your neck movements are going to be transferred to those vertebrae below the fusion. In many patients, all this accomplishes is transferring the atlantoaxial instability to the lower cervical vertebrae.

The following research highlights these problems:

Surgery is often aimed at fixing the instability by fusing vertebral segments together.

Destabilization of C0-C1 or C1-C2 joints can lead to extremes of instability with severe life-threatening neurologic sequelae that necessitate surgical consult. On several occasions, we have stopped a person in the middle of a motion x-ray examination because of how severe the instability was on the exam. Patients or athletes with serious symptoms after head or neck trauma including dysarthria, diplopia, dysphagia, drop attacks, paraesthesias, or weakness in the limbs (especially the legs) necessitate surgical consultation. If radiographic analysis confirms significant upper cervical instability, then surgical fusion is performed. But the vast majority of people with a myriad of symptoms do not meet the criteria for surgical fusion, yet they are sent to fusion surgery anyway.

In a study (July 2018) published in the Archives of Orthopaedic and Trauma Surgery, (18) doctors examined occipitoaxial fusion for atlantoaxial instability. Surgery is often aimed at fixing the instability by fusing vertebral segments together. In the case of C1-C2 instability, these two vertebrae are fused posteriorly to limit their amount of movement. However, it may limit motion so much that patients become completely unable to move that portion of their neck. In addition, fusion operations can accelerate the degeneration of adjacent vertebrae as the motion in the neck is distributed more on these issues. For example, if you fuse the C1 and C2 vertebrae together, extra motion is placed on the remaining vertebrae during normal neck movement, accelerating the degeneration process and further contributing to chronic neck pain.

Adjacent segment degeneration after cervical fusion surgery was 32.8%

A 2019 study published in the International Orthopaedics (19) found Adjacent segment degeneration after cervical fusion surgery was found in 32.8% of patients.  Of those approximately 1/4-1/3 progressed to adjacent segment disease.

  • Risk factors after cervical fusion surgery were young age, pre-existing disc degeneration, short fusion segment, high T1 slope, disruption of adjacent soft tissue, and plate placement close to the adjacent disc.
  • 41 patients underwent occipitoaxial fusion for atlantoaxial instability.
    • Fifteen patients with postoperative adjacent segment disease. (Complications of pain and mobility)
    • Twenty-six patients without postoperative adjacent segment disease.
  • Fifteen patients with postoperative adjacent segment disease had a high incidence of sub-axial subluxation (displacement of the vertebrae below the fusion) and swan neck deformity (extreme, unnatural curvature in the neck).

This type of surgery, with its high complication rate and similar procedures, may not even be necessary. 

Cervical spine ligament weakness is why many cervical neck pain patients do not have a successful surgery.

Doctors at the University of Waterloo in Canada published research in the Spine Journal (20) where they were attempting to define a new clinical scoring system for patients with cervical neck instability. The scoring system would help identify the role of cervical ligaments in difficult-to-treat neck pain and instability.

This is what came out of this research:

  • “Predicting the physiological (normal) range of motion (ROM) using a finite element (FE) model (a numeric scoring system) of the upper cervical spine requires the incorporation of ligament laxity.”
    • Our comment: The doctors understand that ligament laxity is a problem of stability and range of motion in the neck.
  • The effect of ligament laxity can be observed only on a macro level of joint motion and is lost once ligaments have been dissected and preconditioned for experimental testing.
    • Our comment:  It is hard on any level to accurately determine the amount of ligament damage to the amount of instability because even small injuries or damage, sometimes undetectable, cause big problems.
  • As a result, although ligament laxity values are recognized to exist, specific values are not directly available in the literature for use in finite element models.
    • Our comment:  Ligament laxity is a mystery and why cervical neck pain patients have a difficult time finding the right medical care.

Surgery, unless a life-threatening or extreme situation, should never be considered until the problems of the cervical ligaments are addressed.

Cervical ligament injury should be more widely viewed as a key, if not THE key, to atlantoaxial instability treatment

In a 2015 paper appearing in the Journal of Prolotherapy, our staff along with our co-writer Paul Fisher wrote that cervical ligament injury should be more widely viewed as a key, if not THE key, to chronic neck pain and various cervical neck-related disorders including atlantoaxial instability treatment. In our opinion, in many patients, cervical ligament injury is the underlying pathophysiology (the cause of) atlantoaxial instability and the primary cause of cervical myelopathy (disease). (21)

This was a continuation in the series of published research Caring Medical is producing on the problems of cervical instability including the 2014 article Chronic Neck Pain: Making the Connection Between Capsular Ligament Laxity and Cervical Instability led by Danielle Steilen. (22)

In that research, our team suggested that the cervical capsular ligaments are the main stabilizing structures of the facet joints in the cervical spine and that they are a major source of chronic neck pain. The instability these injuries create often reflects a state of instability in the cervical spine and is a symptom common to a number of conditions including disc herniation,

In the upper cervical spine (C0-C2), this can cause a number of other symptoms including, but not limited to, nerve irritation and vertebrobasilar insufficiency with associated cervical vertigo, dizzinesstinnitus, facial pain, arm pain, and migraine headaches.

An overstressed transverse ligament may be the culprit to your myriad of symptoms

In June 2017, German researchers publishing in Zeitschrift für Orthopädie und Unfallchirurgie (Journal of Orthopedics and Trauma Surgery) also saw the connection between damaged cervical ligaments and chronic neck problems. Here is what they wrote:

  • The odontoid process (the protruding bony process of the C2 (Axis)) and the transverse ligament are the most important structures stabilizing the atlantoaxial complex.
  • There is not a clear understanding of how injuries of these structures contribute to neck instability and a potential narrowing of the spinal canal.

The German team set out to investigate in human cadaver studies, the fracture and displacement of the odontoid process and ruptures and tears of the transverse ligament. After examination and compilation of data, the researchers concluded:

  • “Our results demonstrate that a relevant constriction of the spinal canal may be due to isolated or combined injuries of the bone and the transverse ligament. Furthermore, our results show the importance of posttraumatic immobilization of the spine with a view to the role of the transverse ligament for stabilization of the atlantoaxial complex.”(23(Neck collars and other devices).

The primary ligamentous support of the lateral or side facet joints of C1-C2 are the capsular ligaments; whereas the atlanto-dens joint is held together by the transverse ligament and its backup the alar ligaments.

The C1-C2 atlantoaxial joint provides 50% of cervical spine rotational mobility as the arch of C1 rotates around the dens of C2. The atlantoaxial joint when stable allows some flexion but
almost no lateral flexion. Lateral flexion in this joint is one of the hallmark signs of facet atlantoaxial instability (FAAI). In other words, you should not be able to touch your shoulder with your ear without moving your arm up to meet your head.

In the medical literature, generally, atlantoaxial instability refers to the connection between the atlas and the dens of the axis, which we refer to as dens atlantoaxial instability (DAAI). This is important because dens atlantoaxial instability is more of a surgical repair type lesion; whereas, facet atlantoaxial instability can more often be treated by conservative measures such as chiropractic care, physiotherapy, and Prolotherapy.

Stability against the anterior translation of the atlas (the C1 wandering over the C2) is by the capsular ligaments posterior (in the back) and the transverse ligament anteriorly (in the front).  Capsular ligament injury of C1-C2 results in facet atlantoaxial instability whereas injury of the transverse and the alar ligament causes dens atlantoaxial instability. Injury to the atlantoaxial capsular ligaments causes a dramatic increase in lateral bending and axial rotation motion; whereas transverse ligament disruption significantly increases the anterior atlanto-dens interval. The anterior atlanto-dens interval is the horizontal distance between the C1-C2. The more distance, the more displacement, the more “wandering,” and the more compression.

Cervical Spine Stability and Restoring Lordosis

The cervical spine has a natural curve. It acts as a spring or shock absorber for the head. When this curve is gone because of injury, Joint Hypermobility Syndrome, or degenerative cervical disc disease, not only are the arteries and nerves between the vertebrae not protected from the impact of walking or running or jumping, or a bumpy car ride, but they are subjected to compression from cervical spine instability caused by cervical ligaments that have also been damaged by injury or wear and tear and no longer hold the neck in correct alignment.

The cervical spine has a natural curve. It acts as a spring or shock absorber for the head. When this curve is gone, injury, Joint Hypermobility Syndrome, or degenerative cervical disc disease
The cervical spine has a natural curve. It acts as a spring or shock absorber for the head. When this curve is gone, injury, Joint Hypermobility Syndrome, or degenerative cervical disc disease

Digital motion X-Ray C1 – C2

The digital motion x-ray is explained and demonstrated below. This is one of our tools in demonstrating cervical instability in real-time and motion. Most injuries to the upper or lower cervical spine are not identified by standard or static x-rays, CT scans, or MRIs. Functional or dynamic imaging technology, which images a person while joints are under stress or in extremes of motion is more sensitive in diagnosing instability. Digital motion x-rays or stress cervical radiographs are obtained using open-mouth projections in neutral, left, and right cervical lateral flexion as well as rotation to reveal a significant lateral offset of one of the lateral masses of C1 on C2.

The clinical signs of upper cervical instability can vary from no symptoms or relatively diffuse complaints to signs and symptoms of extreme importance or seriousness. When clinical symptoms are present, assessing the degree of instability by objective means including digital motion x-ray helps in determining the treatment course.

 

  • Digital Motion X-ray is a great tool to show instability at the C1-C2 Facet Joints
  • The amount of misalignment or “overhang” between the C1-C2 demonstrates the degree of instability in the upper cervical spine.
  • This is treated with Prolotherapy injections (explained below) to the posterior ligaments that can cause instability.
  • At 0:40 of this video, a repeat DMX is shown to demonstrate the correction of this problem.

The challenges of cervical instability are many. Fixing cervical neck instability is not something that can be treated simply or easily, it takes a comprehensive non-surgical program to get the patient’s instability stabilized and the symptoms abated. We believe that if you have been going from clinician to clinician, practitioner to practitioner, doctor to doctor, there is a good likelihood that you have problems of cervical neck instability coming from weakness and damage to the cervical ligaments.

Treatment Prolotherapy

The clinical signs of upper cervical instability can vary from no symptoms or relatively diffuse complaints to signs and symptoms of extreme importance or seriousness. When clinical symptoms are present, assessing the degree of instability by objective means including digital motion x-ray helps in determining the treatment course. It can guide which ligaments need to be injected with Prolotherapy. Destabilization of C0-C1 or C1-C2 joints can lead to extremes of instability with severe life-threatening neurologic sequelae that necessitate surgical consult. On several occasions, we have stopped a person in the middle of a motion x-ray examination because of how severe the instability was on the exam. Patients or athletes with serious symptoms after head or neck trauma including dysarthria, diplopia, dysphagia, drop attacks, paraesthesias, or weakness in the limbs (especially the legs) necessitate surgical consultation. If radiographic analysis confirms significant upper cervical instability, then surgical fusion is performed. But the vast majority of people with a myriad of symptoms do not meet the criteria for surgical fusion. So what are those suffering people to do?

  • To get the brainstem and all the nerves working correctly one has to address and tighten the ligaments in the back of the neck as well as get the cervical curve back to its normal lordotic configuration.

The way we do this at Caring Medical is with Prolotherapy treatments.

We have published dozens of papers on Prolotherapy injections as a treatment in difficult-to-treat musculoskeletal disorders. Prolotherapy is an injection technique utilizing simple sugar or dextrose. We are going to refer to two of these studies as they relate to cervical instability and a myriad of related symptoms including those mentioned above in relation to the brainstem. It should be pointed out that we suggest in our research that “Additional randomized clinical trials and more research into its (Prolotherapy) use will be needed to verify its potential to reverse ligament laxity and correct the attendant cervical instability.” Our research documents our experience with our patients.

In the above research, we have made the case that the complexity of your problems may be caused by cervical instability caused by weakened and damaged cervical spine ligaments. Now we will begin to make the case that your symptoms may be alleviated on a long-term more permanent basis with the use of Prolotherapy.

Prolotherapy is a regenerative injection technique that utilizes substances as simple as dextrose to repair and regenerate damaged ligaments.

In 2015, Caring Medical published findings in the European Journal of Preventive Medicine investigating the role of Prolotherapy in the reduction of pain and symptoms associated with increased cervical intervertebral motion, structural deformity, and irritation of nerve roots.

Twenty-one study participants were selected from patients seen for the primary complaint of neck pain. Following a series of Prolotherapy injections, patient-reported assessments were measured using questionnaire data, including a range of motion (ROM), crunching, stiffness, pain level, numbness, and exercise ability, between 1 and 39 months post-treatment (average = 24 months).

  • Ninety-five percent of patients reported that Prolotherapy met their expectations in regard to pain relief and functionality. Significant reductions in pain at rest, during normal activity, and during exercise were reported.
  • Eighty-six percent of patients reported overall sustained improvement, while 33 percent reported complete functional recovery.
  • Thirty-one percent of patients reported complete relief of all recorded symptoms. No adverse events were reported.

We concluded that statistically significant reductions in pain and functionality, indicate the safety and viability of Prolotherapy for cervical spine instability. (26)

How do I know if I’m a good candidate?

Lightheadedness or dizziness is a very common symptom, for which people often get a lot of x-rays, MRIs, EKGs, and blood tests. It is an extremely common complaint when people come to Caring Medical with neck complaints. There are many reasons for a person with AAI to have lightheadedness or dizziness. The most likely cause is a decrease in sympathetic nerve fiber firing on blood vessels causing vasodilation. Another reason is carotid sinus syncope. In this condition, a sharp movement of the neck causes a vasodepressor response, and the blood pressure and pulse rate become dangerously low so blood supply to the brain is diminished and lightheadedness, fainting, or severe fatigue can result. When AAI is present, various afferent or sensory nerves may not send the right signals to the brain stem, as even the glossopharyngeal nerve is extremely close to the atlas and axis. This could then cause the NTS to sense that blood pressure is too high and cause an overstimulation of the vagus nerve and account for the low blood pressure and pulse. For more information please see my article Ross Hauser, MD Reviews Cervical Spine Instability and Potential Effects on Brain Physiology.

The general major criteria we use at Caring Medical for diagnosing cervical instability based on patient history includes:

  • Cracking or crepitation with the motion of the neck (heard or felt)
  • Suboccipital headache or tension
  • Chronic neck stiffness
  • Major symptoms relieved by rest or head support
  • Major symptoms aggravated or started with neck and/or head motion
  • Self-manipulation

It can also include these more specific (minor) criteria:

  • History of overzealous chiropractic or osteopathic manipulation
  • Migraines
  • Vertigo
  • Tinnitus
  • Dizziness/lightheadedness
  • Significant trauma to the head or neck
  • Job/lifestyle that involves a significant amount of time in forward head posture

In our experience, someone who has four of the major criteria and at least four of the minor criteria has cervical instability and typically needs treatment with Prolotherapy. There are exceptions to this, of course, and each case needs to be evaluated on its own merits.

We hope you found this article informative and it helped answer many of the questions you may have surrounding your neck pain. Just like you, we want to make sure you are a good fit for our clinic prior to accepting your case. While our mission is to help as many people with chronic pain as we can, sadly, we cannot accept all cases. We have a multi-step process so our team can really get to know you and your case to ensure that it sounds like you are a good fit for the unique testing and treatments that we offer here.

Please visit the Hauser Neck Center Patient Candidate Form

1 Nouri A, Martin AR, Mikulis D. Magnetic resonance imaging assessment of degenerative cervical myelopathy: a review of structural changes and measurement techniques. Neurosurg Focus 2016: 50(6):. doi: 10.3171/2016.3.FOCUS1667. [Google Scholar]
2 Goel A. Craniovertebral junction instability: a review of facts about facets. Asian spine journal. 2015 Aug;9(4):636. [Google Scholar].
3 Cook C, Brismée JM, Fleming R, Sizer Jr PS. Identifiers suggestive of clinical cervical spine instability: a Delphi study of physical therapists. Physical Therapy. 2005 Sep 1;85(9):895-906. [Google Scholar]
4 Neal M, Gibbs W, Lyons M. Atlantoaxial Osteoarthritis: A Well-Established Entity that Remains Frequently Overlooked. Turkish Neurosurgery. 2021 Jul 9. [Google Scholar]
5 Guha D, Mohanty C, Tator CH, Shamji MF. Occipital neuralgia secondary to unilateral atlantoaxial osteoarthritis: case report and review of the literature. Surgical neurology international. 2015;6. [Google Scholar]
6 Shah A, Vutha R, Prasad A, Goel A. Central or axial atlantoaxial dislocation and craniovertebral junction alterations: a review of 393 patients treated over 12 years. Neurosurg Focus. 2023 Mar;54(3):E13. doi: 10.3171/2022.12.FOCUS22634.
7 González DC, Ardura Aragón F, Sanjuan JC, Maniega SS, Andrino AL, García Fraile R, Labrador Hernández G, Calabia-Campo J, Caballero-García A, Córdova-Martínez A. C1-C2 Rotatory Subluxation in Adults “A Narrative Review”. Diagnostics. 2022 Jul 2;12(7):1615. [Google Scholar]
8 Coronado R, Hudson B, Sheets C, Roman M, Isaacs R, Mathers J, Cook C. Correlation of magnetic resonance imaging findings and reported symptoms in patients with chronic cervical dysfunction. Journal of Manual & Manipulative Therapy. 2009 Jul 1;17(3):148-53. [Google Scholar]
9 Hutting N, Scholten-Peeters GG, Vijverman V, Keesenberg MD, Verhagen AP. Diagnostic accuracy of upper cervical spine instability tests: a systematic review. Physical therapy. 2013 Dec 1;93(12):1686-95. [Google Scholar]
10 Henderson Sr FC, Henderson Jr FC. Diagnosis of Atlantoaxial Instability Requires Clinical Suspicion to Drive the Radiological Investigation. J Spine 6: 364. doi: 10.4172/2165-7939.1000364. [Google Scholar]
11 Stokes IA, Iatridis JC. Mechanical conditions that accelerate intervertebral disc degeneration: overload versus immobilization. Spine. 2004 Dec 1;29(23):2724. [Google Scholar]
12 Mauro A, Eisenstein SM, Little C. Are animal models useful for studying human disc disorders/degeneration. Eur Spine J. (2008) 17:2-19. [Google Scholar]
13 Virk SS, Niedermeier S, Yu E, Khan SN. Adjacent segment disease. Orthopedics. 2014 Aug;37(8):547-555. DOI: 10.3928/01477447-20140728-08. [Google Scholar]
14 Phuntsok R, Ellis BJ, Herron MR, Provost CW, Dailey AT, Brockmeyer DL. The occipitoatlantal capsular ligaments are the primary stabilizers of the occipitoatlantal joint in the craniocervical junction: a finite element analysis. Journal of Neurosurgery: Spine. 2019 Feb 15;30(5):593-601. [Google Scholar]
15 Nishida N, Tripathi S, Mumtaz M, Kelkar A, Kumaran Y, Sakai T, Goel VK. Soft tissue injury in cervical spine is a risk factor for intersegmental instability: a finite element analysis. World Neurosurg. 2022 May 2:S1878-8750(22)00565-4. doi: 10.1016/j.wneu.2022.04.112. Epub ahead of print. PMID: 35513283. [Google Scholar]
16 Zakaria Z, Sharifudin MA, Din H, Abd Aziz A, Karupiah RK. Correlation Study Between Clinical Special Tests for Myelopathy and Static MRI Parameters in Patients of Malaysian Population Treated for Cervical Dysfunction. Cureus. 2021 Oct 16;13(10). [Google Scholar]
17 Wang HW, Ma LP, Yin YH, Yu XG, Meng CL. Biomechanical Rationale for the Development of Atlantoaxial Instability and Basilar Invagination in Patients with Occipitalization of the Atlas: A Finite Element Analysis. World neurosurgery. 2019 Mar 26. [Google Scholar]
18 Wu X, Qi Y, Tan M, Yi P, Yang F, Tang X, Hao Q. Incidence and risk factors for adjacent segment degeneration following occipitoaxial fusion for atlantoaxial instability in non-rheumatoid arthritis. Archives of orthopedic and trauma surgery. 2018 Jul 1;138(7):921-7.  [Google Scholar]
19 Hashimoto K, Aizawa T, Kanno H, Itoi E. Adjacent segment degeneration after fusion spinal surgery—a systematic review. International orthopedics. 2019 Apr;43(4):987-93.
20 Lasswell TL, Cronin DS, Medley JB, Rasoulinejad P. Incorporating ligament laxity in a finite element model for the upper cervical spine. The Spine Journal. 2017 Jun 30. [Google Scholar]
21 Hauser R, Steilen-Matias D, Fisher P. Upper cervical instability of traumatic origin treated with dextrose prolotherapy: a case report. Journal of Prolotherapy. 2015;7:e932-e935.
22 Steilen D, Hauser R, Woldin B, Sawyer S. Chronic neck pain: making the connection between capsular ligament laxity and cervical instability. The open orthopedics journal. 2014;8:326. [Google Scholar]
23 Meyer C, Bredow J, Heising E, Eysel P, Müller L, Stein G. Influence of Osseous and Ligamentous Injuries on the Stability of the Atlantoaxial Complex. Zeitschrift fur Orthopadie und Unfallchirurgie. 2017 Jun;155(3):318.  [Google Scholar]
24 Rosenberg WS, Salame KS, Shumrick KV, Tew JM Jr. Compression of the upper cervical spinal cord causing symptoms of brainstem compromise. A case report. Spine (Phila Pa 1976). 1998;23(13):1497-1500. doi:10.1097/00007632-199807010-00013 [Google Scholar]
25 Henderson FC, Wilson WA, Mark AS, Koby M. Utility of the clivo-axial angle in assessing brainstem deformity: pilot study and literature review. Neurosurgical review. 2018 Jan 1;41(1):149-63. [Google Scholar]
26 Hauser RA, Steilen D, Gordin K. The Biology of Prolotherapy and Its Application in Clinical Cervical Spine Instability and Chronic Neck Pain: A Retrospective Study. European Journal of Preventive Medicine. 2015;3(4):85-102. [Google Scholar]

 

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