Structural High Blood Pressure- Neck instability can affect blood pressure

Ross Hauser, MD explains how the vagus and glossopharyngeal nerves are involved in regulating blood pressure and how these nerves can be impaired due to upper cervical instability, resulting in abnormal blood pressure. This can happen in otherwise healthy people, which can leave the patient and provider frustrated and trying medications that may not be the best long term option.

We all know the importance of high blood pressure. High blood pressure is the silent killer of the heart. High blood pressure may not cause any symptoms so it is important to have yours checked regularly. This way you can have it treated. This article and video will tackle the subject of high blood pressure a little differently. It will cover topics as they relate to the epidemic of young people or people who are into good health and lifestyle and who are now suffering from high blood pressure without an understandable reason for it.

Generally, we know that if somebody eats really poorly and has a lot of extra weight and may have diabetes, or they smoke, that those things can lead to high blood pressure. This article however, deals with the neurology of high blood pressure. This is when the cardiovascular tests check out fine and it is determined that the patient’s high blood pressure is not a problem being generated by the heart or the familiar and typical causes of high blood pressure that surround lifestyle choices.

But, most people we see or who contact us, this high blood pressure is one symptom of many. For many of these people, the most common co-existing conditions of high blood pressures, i.e., obesity, diabetes, metabolic syndrome, are not the problems that these people suffer from. In fact many of these people lead “healthy” lifestyles with good diets and proper weight. They get blood work done and it comes back “normal.” So if not the cardiovascular symptoms, what then? The answer may lie in a neurologic-like group of symptoms being caused by upper cervical instability. It is these symptoms, headache, craniofacial pain, vertigo, dizziness, vision problems, hearing problems, anxiety and depression, among many, that may be the clue that a combination of high blood pressure and neck pain in a seemingly elsewise healthy person is being caused by upper cervical spine instability. Yet, despite these clues, this connection between neck pain and high blood pressure is often overlooked or if a connection is made it is thought that the pain itself is causing high blood pressure and that if the pain can be alleviated with medications, there is a chance that the blood pressure will come down.

In summary, for the person who has high blood pressure and they’ve tried specific dieting they have a relatively peaceful lifestyle there may be a structural cause of the high blood pressure that’s what we’re going to talk about in this video and article.

90% of cases are called essential (or primary) hypertension – This non-specific diagnosis leads to suboptimal therapeutics and a major problem with non-compliance.

Not being able to pinpoint an exact cause of hypertension or high blood pressure is a very common occurrence. If one studies high blood pressure, about 90% of cases are called essential (or primary) hypertension. Essential means there’s no known obvious cause for this person to have high blood pressure. In this video and article we will discuss the possibility that some people have essential hypertension because of compression caused by cervical spine instability.

Dr. Hauser refers to a 2011 study from doctors at the Department of Cardiology, Endocrine and Diabetes Unit, Christian Medical College. (1) This paper begins, “As our understanding of the underlying aetiology of hypertension is far from adequate, over 90% of patients with hypertension receive a diagnosis of essential hypertension. This non-specific diagnosis leads to suboptimal therapeutics and a major problem with non-compliance.” In other words, we don’t know the cause so we’re just going to use medications. If you use medications and you’re not treating the exact cause of the hypertension, you get “suboptimal therapeutics and a major problem with non-compliance.”

Cardiovascular mortality has increased possibly from poor systemic blood pressure control.

In about 90% of cases the etiology of the high blood pressure is unknown, thus the diagnosis of essential hypertension. Blood pressure has to be controlled. Unfortunately, when the cause of high blood pressure is not truly understood the following occurs:

1. Most people are treated nonspecifically.
2. More side effects from inappropriate choice of therapy.
3. Results in over 50% noncompliance rates.

Cardiovascular mortality has increased from around 25% in 1990 to more than 40% in 2020, possibly from poor systemic blood pressure control.

For example, a common medication used for high blood pressure is propranolol or beta blockers. Beta blockers are known to cause depression and they slow metabolism. (They slow the sympathetic system or they inhibit the sympathetic system which has to do with energy and vitality.) This makes some people feel terrible, more depressed and fatigued. People do not want to have these symptoms so they stop taking the medication and then are non-compliant. No they have high blood pressure that is not getting treated appropriately.

Studies have found that the cardiovascular mortality rate has gone from 25% in 1990 to 40% in 2020. The number one killer still is cardiovascular disease and a lot of cardiovascular disease can come from unresolved high blood pressure.

In the image below we see the components, organs, and glands of blood pressure.

Vascular
Brain
Adrenal glands
Pituitary gland
Kidneys
Heart

As we can see, there are many organs and glands involved in how the body regulates blood pressure. When somebody has chronic high blood pressure, and the body senses the damaging effects the blood pressure can have, the central nervous system gets involved to send messages through the neurological network to release chemicals and other substances to try to bring that blood pressure down. The body does this through the Vagus Nerve.

Understanding the vagus nerve

I have a series of articles on the vagus nerve on this website: For a summary explanation of the vagus nerve I present a brief review from my article: Vagus nerve compression in the neck: Symptoms and treatments.

The vagus nerve is also noted as being the tenth cranial nerve (designated as CN X). The vagus nerve is actually a set of two nerves, a vagus nerve right side of the neck and a vagus nerve left side of the neck.

The vagus nerve is a 2-way messenger network, passing messages and signals between the organs and brain to maintain heart rate, blood pressure, circulation, breathing, internal organ distension (for example the moving of food through the digestive system), secretions, and inflammation. As we will see below the vagus nerve helps us talk, swallow, focus vision, hear, and understand. The vagus nerve also sends out messages as part of the parasympathetic nervous system that “calms down” the body after physical exertion or in response to stress in a “fight or flight” situation. Let me explain this further.

The sympathetic nervous system is part of the autonomic nervous system. It helps make adaptations to your current situation. For instance, if you are witness to a crime or an accident, or something bad, your body shifts into “fight-or-flight mode.” Your heart rate, blood pressure, and breathing rate dramatically increase.
The parasympathetic nervous system is an energy management center. When you are done being in “fight or flight mode,” or are using techniques to end a panic attack to catch your breath or calm yourself down. The parasympathetic nervous system helps automatically reduce heart rate and blood pressure. As opposed to “fight or flight,” the parasympathetic nervous system is often described as “rest and digest,” as it signals to send blood back into the gut and digestive system.

The Vagus nerve and the Glossopharyngeal nerve

The vagus nerves innervates the internal organs of the body and their interactions with the brain, spinal cord, cranial nerves, upper cervical spinal nerves, and sympathetic nervous system. Sensory functions of the vagus nerve are critical for conscious perception and for monitoring visceral functions (heart beats for example) in the cardiovascular system. As such the vagus nerve has a critical role in the maintenance of blood pressure and heart rate control.

The vagus nerve innervates the aortic arch (cervical cardiac branches). The right vagus nerve (more so than the left) innervates the SA node and the AV node off the heart. (This is why vagus nerve stimulators are placed on the left side).

In the cervical region, the vagus nerve supplies branches to the Glossopharyngeal nerve. The nerves serve to help drain blood from the brain into the carotid sinus into the carotid artery in your neck. Dysfunction would cause brain drainage problems and high blood pressure problems.

What are we seeing in this image? This is a good summary of the vagus nerve and the glossopharyngeal nerve monitoring the blood pressure and pulse in the body.

The afferent information, that is messages from the cardiovascular system, in this case, the baroreceptors that send messages on blood pressure to the brain is relayed through the nucleus tractus solitarius. The nucleus tractus solitarius is a nervous system relay station that receives and responds to various messages including those of blood pressure levels and the medulla sends messages back to the cardiovascular system about what to do with these blood pressure levels.). If the signals to the brain that the heart is racing or blood pressure is elevated are not correctly received, the correct message back to slow the heart rate down is never sent.

The upper cervical vertebrae-vagus nerve-baroreceptor connection.

The vagus and glossopharyngeal nerves run just in front of the upper cervical vertebrae (atlas and axis) and branch to innervate the receptors in the carotid sinus and aortic arch that control blood pressure.

When atlanto-axial instability is present, blood pressure issues (along with heart rate and rhythm problems) can occur because of impaired vagus and glossopharyngeal nerve function.

The carotid sinus or carotid bulb which is at in the mid-neck region is innovated by the glossopharyngeal nerve. When blood pressure is too high, the sensors in the glossopharyngeal nerves send off signals to the brain stem to start the process of lowering blood pressure. The Vegas nerves innervate the aortic arch, that’s another sensor of what’s going on in the blood pressure. If these sensors for blood pressure are off and the person might have high blood pressure one day low blood pressure the next day.

High blood pressure may be caused by Baroreflex Dysfunction which can be caused by any compression on the nerves, arteries, and veins that pass through the neck, such as compression or injury on the carotid sinus nerve, a branch of the glossopharyngeal nerve. In this scenario, a spike in high blood pressure may be caused by simply turning your head one way or the other and creating compression or pressure on the glossopharyngeal nerve.

It’s important to understand that the cervical sympathetic ganglion run right along the spinal cord and the superior cervical sympathetic ganglion is right at the C2 level. Any type of ligament injury or degeneration in the cervical spine can lead to compression or pinching and dysregulation of the autonomic nervous system and throw the regulation of blood pressure off.

The superior cervical sympathetic ganglion is typically located between the internal carotid artery and the longus capitis muscle near the transverse processes at the C2-C3 level and have regular communications with the vagus and glossopharyngeal nerves.

In the illustration below we can demonstrate how the nerves wrap around the arteries. Let’s help explain this with a quote from an August 2021 paper in the journal Cardiovascular diabetology (2)

“Maintenance of cardiovascular homeostasis (the balance and functioning of the cardiovascular system including blood pressure regulation) requires continual redirection of blood flow to ensure adequate blood supply to active tissues. Under normal functioning, the autonomic nervous system, comprising the sympathetic, parasympathetic and enteric nervous systems, makes unconscious adjustments in regional blood flow and cardiac output, and coordinates with the central respiratory network in order to respond to varying metabolic and thermoregulatory demand.”

In other words, the autonomic nervous system is monitoring blood flow demands required at activity, at rest, etc., to help determine blood pressure needs to get blood where it needs to be. It does this through sympathetic tone increases which releases hormones and chemicals to influence the heart rate. The vagus nerve inhibits the sympathetic tone. The vagus nerve is intimately involved in the regulation of blood pressure.

What are we seeing in this image?

This is the superior cervical sympathetic ganglion in its native habitat. Surrounded by blood vessels (internal carotid artery and internal jugular vein) and nerve networks and near the C2 vertebrae. When the vertebrae wander out of position, the veins, arteries, nerves, and nerve bundles surrounding and interwoven with them cause compression and stretching of these vital structures. In the context of this article, this compression and stretching can not only cause pain but disrupt nerve signals causing cardiovascular-like symptoms and conditions already outlined in this article.

In the brain stem there’s a cardioinhibitory center that can affect the autonomic nerve supply to the heart so basically the glossopharyngeal nerve and the vagus nerve, they’re going to send signals up into the medulla the brain stem which sits right above C1 and it’s going to give it input about what to do so if blood pressure is low there’s going to be sympathetic discharges to stimulate the sympathetic system to clamp down on the blood vessels to raise blood pressure and if blood pressure is too high it’s going to inhibit the sympathetic tone so the blood vessels dilate.

In the image below this shown.

The vagus nerve decreases heart rate via the parasympathetic nervous system. The sympathetic cardiac nerves increase heart rate and force of contraction.

(10:24) The image below shows the atlas or C1 and the C2 and how the glossopharyngeal nerve and the vagus run right along the back of the vertebral bodies. The ganglion of the vagus nerve especially the no-dose ganglion sits right at C1. If you have upper cervical spine instability, if your cervical spine ligaments are stretched or weakened, your Atlas will move too far forward and compress the vagus nosdoe ganglion and when the no dose ganglion gets a compressed, the vagus nerve diameter becomes smaller and one symptom would be a dysregul;ation of blood pressure. In other words, blood pressure problems being caused by a structural issue in the neck.

Again, once the vagus nerve is injured, the body can lose some of its ability to regulate blood pressure and your blood pressure can go up. Part of the reason is that the delicate balance between the sympathetic nervous system and the parasympathetic nervous system (up and down regulation systems). The following are simple tests that may tell you whether you’re sympathetic system and parasympathetic system are in balance.

Light sensitivity, pupil dilation. A constantly dilated pupil means there’s too much sympathetic nervous system activity not enough parasympathetic nervous system activity. The sympathetic system is the system that raises blood pressure.
No Gag reflex. or absent gag reflex. When a patient comes into our office, I will explore the back of the throat with a tongue blade or tongue depressor. In normal function, when provoked by stimulation to the back of the throat, a person gags, they cough. In some people I get no gag response. The sensory branch of the gag reflex is the glossopharyngeal nerve at the back of the throat. The connection of the vagus nerve is that when the glossopharyngeal nerve evokes a gag reflex, the vagus nerve stimulates the neck muscles to contract. There is a disconnect between the glossopharyngeal nerve and vagus nerve if there is no gag reflex. The same disconnect can cause blood pressure sensors to dysfunction. The vagus nerve is supposed to send inputs to slow the heart rate down and eventually cause inhibition of the sympathetic system and then the arteries dilate the blood pressure goes down.

The glossopharyngeal and vagus cranial nerves provide the brainstem with sensory inputs from different receptors in the heart, lung, and vasculature. This afferent information (information generated by the nerves and sent to the brain) is critical for the short-term regulation of arterial blood pressure and the buffering of emotional and physical stressors.

Lesions that selectively destroy the afferent fibers of the vagus and/or glossopharyngeal nerves can interrupt the transmission of baroreceptor signaling, leading to extreme blood pressure fluctuations.

Treatments

Let’s look at an August 2021 paper in the International journal of spine surgery (3) discussing the “mystery” of why patients who have decompressive cervical surgery, have among other good outcomes, a normalization of their blood pressure.

The surgeon / authors of this paper write: “The blood pressure of cervical spondylosis patients with hypertension often returns to normal after decompressive cervical surgery. However, the effect of decompressive cervical surgery on the blood pressure of patients with cervical spondylosis has not been rigorously studied.” In other words, blood pressure normalizes in some patients after surgery but no one really knows why and further, this benefit as to why it happens is not well researched.

Here the surgeons, to offer an answer to this question followed 50 consecutive cervical spondylosis patients with hypertension from 2014-2017 and investigated the changes in blood pressure after decompressive cervical surgery. They designed a test to measure systolic blood pressure, diastolic blood pressure, (in doctor’s) office blood pressure, and the percentage of patients on antihypertensive medication. Then through systematic analysis they hoped to understand why blood pressure would decrease. What did they find? They could not, through this testing prove that the surgery lowered the patient’s blood pressure. In this regard the mystery remained. To review, the doctors saw what was already understood, that decompressive cervical surgery could help lower unexplained high blood pressure and that the number of patients requiring post-surgical blood [pressure medications dropped significantly from 84% before surgery to 54% after surgery. However, despite empirical evidence, (the doctors saw that the patients blood pressure was lowered) they could not confirm by multiple-time series tests that the surgery helped. But empirically the surgery did.

Let’s have it understood however that cervical spine surgery does not alleviate high blood pressure in some patients. Going into surgery with a history of high blood pressure from lifestyle choices can lead to very poor outcomes. This is attested to in research published in March 2021 in the journal Spine (4). In this paper, doctors wrote: “Compared with the good (Cervical Laminoplasty) -outcome group, the poor (Cervical Laminoplasty) -outcome group had a significantly higher prevalence of diabetes and hypertension and use of anticoagulant/antiplatelet agent and smoking history.”

Further, a December 2022 paper from the University of Wisconsin School of Medicine and Public Health wrote (5): “Preoperative hypertension, dialysis, and sepsis were risk factors for 30-day readmission following cervical laminoplasty.”

Follow the ligaments and the neurology.

In the image above, Hilton’s Law and Hauser’s Law are discussed.

Hilton’s Law was developed by the 19th century surgeon and anatomist John Hilton. Hilton proposed a better understanding of the way nerves supplied joints with sensation, that is sense of movement, function and pain. Hilton’s fame was that he took nerve signals beyond the muscles to include the ligaments and skin.

Dr. Hauser took this law and focused on the ligaments. Basically, when a patient suffers from many mysterious and seemingly unrelated symptoms, follow the nerves or neurology and you will likely find that ligament damage and instability is the underlying cause. What does that mean? If you have blood pressure without obvious cause, one possible answer is to follow the neurology, that is, are vital nerve networks being compressed and herniated in the neck?

So let’s look at the neurology (the nerve networks) of blood pressure There’s many different organs that are involved in blood pressure. Blood pressure is defined as the pressure the heart has to pump against to get the blood to the feet but especially up to the brain and when blood pressure is over 140 over 90 a person said to have high blood pressure.

In May 2022, doctors in India took up this question, they offered a suggestion (6). They write: “In patients who undergo cervical decompressive surgery for cervical spondylotic myelopathy, significant haemodynamic (blood flow) fluctuations have been reported due to various reasons like autonomic dysfunction and cervical cord compression. . . Due to significant spinal cord compression in cervical spondylotic myelopathy, there occurs chronic irritation of the dura mater (the thick membrane covering) of the cervical spinal cord and the posterior longitudinal ligament (the ligament that runs almost the length of the spine helping to hold the vertebrae in place). It is well known that the cervical disc, dura mater and posterior longitudinal ligament are rich in sympathetic fibers (simply nerve sensors). It seems likely that stimulation of sympathetic nerve fibers (simply pain) in the pathologically degenerative disc and surrounding tissue produces sympathetic excitation and induces sympathetic reflex (simply pain and irritation causes a rise in blood pressure). Surgical decompression of the cervical spine in cervical spondylotic myelopathy will relieve the chronic sympathetic irritation and may decrease blood pressure.)

What are we seeing in this image? This image describes the impact of compression of the vagus nerve and the glossopharyngeal nerve on heart rate and blood pressure

Many of the vagus nerve sensory fibers that regulate blood pressure are in the carotid artery and the glossopharyngeal nerve fibers. When a person has cervical instability especially upper cervical instability it can impact the vagus nerve and the glossopharyngeal nerve. The vagus nerve and the glossopharyngeal nerve run in the carotid sheath, the connective tissue that encapsulates the vascular compartments of the neck. This runs right along the anterior body of the cervical vertebrae especially C1-C2. In patients with cervical instability those nerves can get compressed and they can get stretched. Some of the nerve impulses can be blocked. Fluctuations in blood pressure, without obvious cause to doctors, can occur. But the obvious cause can be the pull and stretching on these nerves caused by wandering cervical vertabrae.

A 2019 paper in the Journal of Clinical Neurophysiology (7) writes: “Lesions that selectively destroy the afferent fibers of the vagus and/or glossopharyngeal nerves can interrupt the transmission of baroreceptor signaling leading to extreme blood pressure fluctuations.”

In the medical publication STAT PEARLS (8) housed at the National Center for Biotechnology Information, U.S. National Library of Medicine an explanation of function for the glossopharyngeal nerve / Carotid baroreceptors connection is given.
- “Carotid sinus baroreceptor has a crucial role in the control of blood pressure and heart rate. Afferent signals (the signals your body sends to the brain describing a current condition – like you need to quickly do something) travel from carotid baroreceptors to the cardiovascular control center in the midbrain via the glossopharyngeal nerve. The efferent signals (your brain’s response to the afferent signals telling your body what to do, in this case, blood flow and blood pressure) transmit via parasympathetic and sympathetic nerves to the heart and blood vessels. This response brings appropriate changes to maintain heart rate and blood pressure in normal physiological limits, which is known as carotid sinus baroreflex (adjustments to the arterial walls to help regulate blood pressure.)

The Vagus Nerve / Aortic Baroreceptors

Returning to the medical publication STAT PEARLS (9) let’s get an explanation of the function of the Vagus Nerve / Aortic Baroreceptors connection. Let’s focus on some of the key points:

“Baroreceptors in the aortic arch and carotid sinus have significant clinical significance. For example, (when the carotid artery is pressed or massaged) there is increased pressure on the carotid artery. Increased pressure on the carotid artery leads to increased signaling of stretch fibers, which causes increased electrical signaling of the baroreceptors from the increased stretch.” (Explanatory note: Messages are going back and forth that the arteries need to stretch to accommodate more blood flow and to handle the increased blood pressure from this blood flow).

The carotid sinus (the carotid sinus has thin membranes that detect blood pressure changes) detects this increased firing of afferent signals (your body is asking the brain for more blood) via the glossopharyngeal nerve, leading to a misinterpretation of the existence of hypertension.

More simply:

Pressure is being created on the carotid artery.
The carotid sinus, the “measuring station” for blood pressure misinterprets this pressure as a cardiac problem of hypertension.
The brain goes into emergency mode sending signals to get the blood pressure down sometimes leading to fainting in the person.

How do you determine whether or not you have a structural cause of blood pressure.

How do you determine whether or not you have a structural cause of blood pressure. In the office we do what’s called a digital motion x-ray. We’re looking for instability of the C1 and C2 vertebrae, are they hypermobile. there’s people that have upper cervical instability in the upper cervical instability is then causing excessive motion or destructive joint motion at the C1 C2 that can injure the glossopharyngeal nerve or the vagus nerve thus the person’s blood pressure sensors off and once the blood pressure senses off then of course a person who can get high blood pressure also when there’s ligament damage in the back of the neck it can cause a change in a person’s cervical curve where it actually blocks the jugular vein and then if it blocks the jugular vein then the brain pressure goes up which is separate to high blood pressure and once the brain pressure is up that can affect the cardio inhibitory center of the of the brain stem as well as other things that are involved in blood pressure in the brain so there’s multiple mechanisms by which upper cervical instability or ligament damage and then that can lead to structural high blood pressure but I’m here to say you absolutely can get it helped by doing curve correction and Prolotherapy.

Ross Hauser, MD. Reviews of Diagnostic Imaging Technology for Cervical Spine Instability

Continued reading: This video and summary is a companion piece to my article Can cervical spine instability cause cardiovascular-like attacks, heart palpitations and blood pressure problems?

Summary and contact us. Can we help you? How do I know if I’m a good candidate?

We hope you found this article informative and that it helped answer many of the questions you may have. 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.

References

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This page was updated Janaury 26, 2013