Restoring Health Through the Vagus Nerve — Using Brain Science to Accelerate Healing: Part 2

Restoring Health Through the Vagus Nerve — Using Brain Science to Accelerate Healing: Part 2

In the United States, our culture has developed a mechanistic understanding of the human body. Patients are often made to think of themselves as machines consisting of flesh and bone. Like cars which have various mechanical systems that enable their function (ignition, electrical, fuel, exhaust, and powertrain systems, for example), people have nearly a dozen biological systems, including the cardiovascular, respiratory, digestive, and central nervous systems. Conventional medicine practitioners are often seen as mechanics whose job it is to find whatever’s broken or not working properly and fix it.

However, the human body is not a machine. It is an organic whole. And as we here at Restoration Healthcare have known and espoused since our founding in 2015, our health and well-being are significantly impacted by the environment in which we exist — not only the physical environment, but also the emotional, psychological, and social environment. As a result, physical illnesses often require more than physical treatments like medication and surgery. They require a change in how we think (psychologically), feel (emotionally), and interact (socially).

For treatment to be effective, it must be integrative. It must also treat the whole patient — not merely the physical body but also the psychological, emotional, and social being. Effective treatment must treat body and mind.

In Part 1 of this series, “Integrating Implicit and Explicit Memory,” we explained how trauma (physical or emotional) causes the fragmentation of implicit and explicit memories and how that fragmentation can negatively impact a person’s health and ability to recover from illness. Only by integrating implicit and explicit memories can someone suffering from trauma — both physical and emotional — move past it and free the body to heal itself.

Here, in Part 2 of this series, we take a closer look at how external psychological, emotional, and social stimuli manifest as physical dysfunction in the body and how certain physical therapies can restore balance and healthy function to the body. This interaction between external stimuli and physical dysfunction can be explained through polyvagal theory.

Understanding Polyvagal Theory

Polyvagal theory was introduced in 1994 by Dr. Stephen Porges, Distinguished University Scientist and Founding Director of Indiana University’s Kinsey Institute Traumatic Stress Research Consortium. Polyvagal theory is an attempt to explain neurological connections between the brain, the various body systems (cardiovascular, respiratory, digestive, immune, and so on), and external stimuli, in order to gain insight into integrated top-down and bottom-up processes involved in mind-body therapies, such as yoga and meditation.

Vagus nerve and Polyvagal theory

The “vagal” in “polyvagal” refers to the vagus nerve — the 10th pair of 12 cranial nerve pairs. Cranial nervesare nerves that connect the brain directly to parts of the body without going through the spinal cord. The vagus nerve is the longest and most complex of the cranial nerves. (Vagus is a Latin word that means “wandering” or “straying.” The vagus nerve is thus named because it follows a complex course throughout the body connecting the brain to several organs.) It runs from the brain through the face and thorax to the abdomen, and it carries signals between the brain and different areas of the body:

  • The skin and muscles
  • Parts of the ear
  • The pharynx, larynx, and soft palate
  • The heart
  • The trachea and lungs
  • The digestive tract, including the esophagus, stomach, and intestines

The vagus nerve, which we first wrote about in June of 2015 in a post titled Vagus Nerve Stimulation May Improve Well Being, plays a key role in the autonomic nervous system (ANS), which controls subconscious life-sustaining bodily processes, including heartbeat, breathing, and digestion. The ANS is divided into two subsystems:

  • The sympathetic nervous system (SNS) is responsible for the fight-or-flight response. In response to a perceived threat, it triggers an adrenaline rush, accelerates heartrate and breathing, constricts blood vessels, and increases blood pressure and sweating.
  • The parasympathetic nervous system (PNS) is responsible for the body’s rest-and-digest response — when the body is relaxed, resting, or feeding. The PNS also facilitates social engagement in safe environments (the tend-and-befriend response).

Pro Tip: Think of the sympathetic nervous system as the accelerator and the parasympathetic nervous system as the brake. Admittedly, this is an oversimplified explanation of how a system as complex as the autonomic nervous system functions, but it provides a general conceptual understanding.

According to polyvagal theory, three neural platforms (or circuits) are linked to self-defense mobilization and immobilization and social interaction. These neural circuits can be linked to three levels of arousal:

  • Fight or flight: Fight and flight are the two initial and primary self-defense mechanisms employed by mammals. Both of these self-defense mechanisms involve an adrenaline rush that ramps up metabolic output, resulting in dramatic physiological changes, including increased muscle tone, shutting down of the digestive system, dilation of the bronchi in the lungs, increased heart rate and respiration, increased blood flow to the large muscles, and heightened sensations. This state is characterized by hypervigilance, anxiety, and disorganized cognitive processing — rigid or chaotic thinking, racing thoughts, obsessive thinking, compulsive behaviors, flashbacks (images or emotions), emotional reactivity, and dread. In this state, we are unable to learn or to interact effectively with others.
  • Tend and befriend: This is the optimal zone of arousal characterized by a deceleration of the autonomic nervous system (ANS) response, stable functioning across all of the body’s systems, emotional tolerance, and normalized sensations. When we’re in a safe environment with people we like, the nervous system supports facial expressivity, prosodic vocalizations (smooth, rhythmic speech), and enhanced hearing of mid-range vocal tones. We are calm, alert, relaxed, aware, and coherent, and we have greater access to intuition and insight. In this state, we can be more social and generally make others feel free safe around us. It also enables us to engage the brain at a higher, cognitive level conducive to new learning.
  • Freeze or faint: Freeze and faint are biological responses to life-threatening dangers. The vagus nerve carries signals between the brain and organs below the diaphragm. When a freeze or faint response is triggered, the vagus nerve signals the body to dramatically decrease metabolic output to conserve resources. This response results in decreased muscle tone, extremely low blood pressure, reflexive defecation and urination, fainting, and an absence of sensations. While fight-or-flight are mobilization responses, freeze and faint are immobilization responses, in which the body feigns death. This is considered to be the most primitive response to existential threats. In freeze mode, we experience slowed or disabled thinking, dissociation of awareness, feelings of isolation or withdrawal, depression, numbness, hopelessness, and disable self-defense responses. In this state, we cannot learn or interact effectively with others.

Healthy development of these neural platforms requires socialization early in development. Infants and young children who are abused or neglected develop strong neural platforms for fight-or-flight and freeze-or-faint responses, but their neural network for rest-and-relax and tend-and-befriend responses are poorly developed. As a result, they may never feel safe, and the chronic stress they experience likely makes them more susceptible to diseases later in life.

Even if we grow up with a healthy balance among these three neural platforms, we need to maintain that balance by getting sufficient rest and relaxation along with healthy social interactions in safe and caring environments.

Recognizing Threats in Today’s World

In the modern world, most of us rarely encounter physical threats that would require us to fight, flee, or faint to preserve our physical safety. Instead, we experience external and internal threats that engage the sympathetic nervous system and parasympathetic nervous system on a more regular or continuous (chronic) basis:

  • External threats may include people or situations that make us feel tense or angry; relationship conflicts; a toxic work environment; the potential loss of job or income; an inability to pay our bills; driving in heavy traffic; frightening news stories; fear of what other people may think of us; loud noises or voices; or, feeling overwhelmed by too much to do in too little time.
  • Internal threats are those the body perceives perhaps even before we become aware of them; such as infections (bacterial, viral, or fungal); an accumulation of toxins that exceeds our body’s threshold; nutritional deficiencies; and, physical injuries.

The vagus nerve carries signals both ways — from the brain to various parts of the body and from those parts of the body to the brain. For example, suppose you don’t have the money to pay your monthly mortgage. You perceive this external pressure as a threat, and you can feel the tension in your gut. Your brain communicates the tension to your gut, and you get “worried sick over it.” Likewise, if you have an infection in your stomach, the vagus nerve senses the threat and lets the brain know about it, so the brain can signal other systems in the body to eliminate the infection. If the infection persists, the signal triggering the stress response continues.

Fear or worry about illness or about the possibility of contracting an illness can also dysregulate the ANS, which is one reason why we should avoid becoming excessively worried over the potential dangers posed by the novel coronavirus. The notion that “the only thing we have to fear is fear itself” applies here.

Certainly, we need to take reasonable precautions, but at the same time we need to dial down the fear. This is true of other illnesses, as well. We are inundated with reminders to get our flu shots, and advertisements are constantly stirring fear over shingles. One possible accompanying antidote for many of these common illnesses may be confidence that our body is well equipped to defend itself.

Using Neuroplasticity to Your Advantage

If you are under constant physical, psychological, emotional, or social stress without getting the restorative rest, relaxation, and positive social engagement you need, imbalances set in that hardwire our neural networks for an always-on stress response. We remain in survival mode and don’t provide our bodies a chance to rest and recover. To make matters worse, when we feel threatened, we become more vigilant and are prone to perceiving even non-threatening people and situations as threats.

Thanks to neuroplasticity, we can rewire our neural networks by eliminating external and internal threats and repeatedly letting our bodies and brains know that we are safe — for example, by slowing our breathing, listening to calming music, and engaging in enjoyable social activities.

Over time, as the ANS (including our vagal neural complex) strengthens, it enables us to self-regulate more quickly and easily to mitigate the stress response, even before we feel stressed. In other words, we can calm ourselves down and engage our cognitive thinking to deal with a situation long before the stress triggers fear, anxiety, or anger, which are usually counterproductive to resolving the situation.

Causes of Poor Vagal Tone

The condition of neural networks that manage the stress response is referred to as vagal tone. Just as we all want well-toned bodies and minds, we want a well-toned vagus nerve to enable us to handle adversity and stress.

Several factors can diminish vagal tone, including the following:

  • Emotional stress from childhood neglect or abuse, emotional trauma, relationship issues, a toxic work environment, family crises, loss of job or income, chronic illness, divorce, death of a loved one, and other emotional events or circumstances
  • Oral such as tooth extraction, braces, jaw misalignment, or mouth breathing, any of which can apply negative stimulation to the vagus nerve
  • Physiological such as infection (bacterial, viral, or fungal), toxicity, or chronic pain
  • Structural such as damage to the vagus nerve from alcohol, diabetes, surgery, toxins, or infection; neck or skull abnormalities (possibly sustained during the birthing process) that disrupt the transmission of nerve signals; or scar tissue from an injury or surgery

An important point in polyvagal theory is that emotional trauma isn’t just psychological, it is also physiological — it impacts the entire body. Calming the autonomic system is essential for restoring health and fitness. At the same time, restoring health and fitness is important for supporting healthy vagus nerve fitness and function.

Identifying Symptoms of Poor Vagal Tone

Dysfunction of the vagus nerve may cause one or more of the following symptoms:

  • Abnormal muscle tone: Too hard/tight (overdeveloped sympathetic nervous system) or too soft/loose (overdeveloped DVC) — for example, a child with an overdeveloped sympathetic nervous system may be prone to walking on his toes
  • Cardiovascular abnormalities: Low or high heartrate, low or high blood pressure, or postural orthostatic tachycardia syndrome (POTS), which is characterized by lightheadedness, fainting, and rapid heart rate upon standing or lying down
  • Chronic inflammation: Mast cell activation syndrome (MCAS), systemic inflammation, or autoimmunity
  • Cranial nerve dysfunction:
    • Uvula (the teardrop-shaped piece of soft tissue that dangles down toward the back of your mouth) doesn’t remain centered when you say “Ah”
    • No gag reflex
    • Hoarse voice
    • Difficulty swallowing
    • Aspiration (swallowing food or liquid “down the wrong pipe”)
    • Tinnitus (ringing in the ears)
    • Dizziness
    • Grinding of teeth
    • Impaired social communication characterized by poor eye contact, monotone speech, and lack of facial expression
  • Gastrointestinal disturbances or imbalances: Acid reflux, bloating, constipation, small-intestinal bacteria overgrowth (SIBO), leaky gut, food sensitivities, irritable bowel syndrome, or inflammatory bowel disease
  • Psychiatric conditions: Anxiety, depression, panic, dissociative identity disorder, depersonalization, or derealization

Improving Vagal Tone

Improving vagal tone involves addressing both external and internal threats and engaging in activities and exercises to strengthen the ventral vagal complex. For example:

  • Addressing external threats: This includes resolving issues in relationships, at work, with your finances, and so on and/or correcting the way you respond to these issues. We also recommend that you pay attention to any external stimuli that create stress, such as the 24/7 news cycle and TV shows or movies that put you on edge. The objective here is to quiet the stress response.
  • Addressing internal threats: Diagnosing and treating any hidden infections, toxic overload, nutrient or micronutrient deficiencies, dietary issues, existing inflammation, and so on are essential to eliminate signals from your body that trigger a stress response.
  • Activities and exercises: You can engage in a variety of activities and exercises to increase positive stimulation of the ventral vagal complex, including interacting with people you enjoy in social settings where you feel safe, meditating, deep breathing, singing or chanting, practicing yoga, dancing, and so on.

But we are getting ahead of ourselves. In Part 3 of this series, we will look at various tools, therapies, and treatments to support the limbic system, including autonomic nervous system testing with our staff to diagnose ANS function, as well as Osteopathic Manipulative Treatment (OMT) — which two of our physicians (Drs. Raleigh and Faraj) offer here at Restoration Healthcare — to restore the body’s incredible ability to heal itself. Tune in next week for Part 3.

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Disclaimer: The information in this blog post about the vagus nerve, is provided for general informational purposes only and may not reflect current medical thinking or practices. No information contained in this post should be construed as medical advice from the medical staff at Restoration Healthcare, Inc., nor is this post intended to be a substitute for medical counsel on any subject matter. No reader of this post should act or refrain from acting on the basis of any information included in, or accessible through, this post without seeking the appropriate medical advice on the particular facts and circumstances at issue from a licensed medical professional in the recipient’s state, country or other appropriate licensing jurisdiction.