Concussion and Eye Movement Series Part 1: Anti-Saccades

Eye movements have become an important diagnostic for patients with neurological disease and dysfunction. It’s one of the reasons we have invested into using extremely sophisticated eye tracking technology so that we can asses and manage patients effectively with traumatic brain injuries.

This will be the first in a series of posts about eye movements that are commonly affected with concussion. The first eye movement we’ll discuss is called anti-saccades.

What’s A Saccade?

In order to know what an anti-saccade is, we have to know what a regular saccade is. A saccade is a fast eye movement that takes your eyes from one target to another. Saccades are the eye movements we use to explore the world around us. They are also eye movements that react very quickly to new things in our environment. These can be a movement in the background, a flashing light, a loud noise, or a touch on our skin.

When we perceive there’s something in our environment that needs our attention, we use saccades almost like a reflex to direct our brain’s attention toward that new stimulus.

What’s an Anti-Saccade

An anti-saccade is a concept developed to see if someone can consciously inhibit a desire to look at something new. During an anti-saccade, we would have you fixate on a central target, and when a new target comes up, we ask you to move your eyes in a spot opposite to where the new target appeared.

The anti-saccade test

Antisaccades require our brain 🧠 to ignore a new stimulus and to create a plan to move the eyes 👀 to a mirror location.

This task requires higher level brain activity because our brains are wired to look at new stimuli. Specifically it requires a functioning prefrontal cortex (PFC).

In patients with concussion, their ability to perform Anti-saccades is compromised where they make frequent eye movements towards the new target, or they take a long time to move their eyes in the opposite direction. This indicates problems with a function called response inhibition. It’s the ability for our brain to stop doing something we don’t want it to do.

This requires a part of our brain called the pre-frontal cortex. Specifically, the dorsolateral prefrontal cortex. We’ll just call it the PFC for short. The PFC is what allows us to inhibit a desire to do something that may be inappropriate.

We need our PFC to stop ourselves from making inappropriate reactions. It’s one of the main differences between an adult brain and a child’s brain is that our PFC keeps us from having meltdowns when something goes wrong.

Parents of toddlers, you guys know what I’m talking about.

So when we take a hit to the head and our PFC goes down, we can have responses that aren’t appropriate. This might mean an emotional outburst, or problems controlling wreckless behavior like uncontrolled gambling. A viable PFC is critical for that and for keeping our bodies from over reacting to stress.

This provides us a meaningful way to assess PFC activity and gives us an way to improve PFC activity using eye movement therapies.

Not only can anti-saccades be used to assess the functionality of someone’s PFC. It can play a role in helping someone rehabilitate their PFC or other aspects of the brain connected to it.

Working on Your Curves: Long Term Outcomes From Fixing Military Neck

I’ll admit that I’ve gone back and forth on the importance of cervical curves in my career. When I was in chiropractic school I was adamant about the importance of cervical curves and how the loss of a curve could affect the progression of spinal arthritis.

Then once I was in practice for a few years, I saw that most neck curves wouldn’t really change very much. Despite the fact that it didn’t change, I’d see really great changes and improvements of many of my patients, so I assumed that it is a nice feature, but probably not necessary to resolving a complaint. You can read some of my previous thoughts on cervical curves here:

I Have Military Neck: Now What?

So What Has Changed my Mind?

I still stand by my previous writings and say that having a proper neck curvature is a really good and positive thing, but you can still get really great results with most secondary conditions even if the neck curve doesn’t come back.

However, I have started to come around on the importance of having a proper neck curvature for the health of the human brain and nervous system. So what changed my mind?

Here are three pretty recent studies looking at the impact that cervical curve changes have on dizziness and cerebral blood flow.

Increase in cerebral blood flow indicated by increased cerebral arterial area and pixel intensity on brain magnetic resonance angiogram following correction of cervical lordosis

The first paper is a study that looked at consecutive patients getting imaging of the arteries going into the brain. Magnetic resonance angiography (MRA) measured the intensity of blood flow with the neck in patients with a straight or military neck pattern. The patients were then placed on a foam orthotic to produce a curve in the neck and a new MRA was taken with the neck in a curved position.

Before and after changes in blood flow to the brain using a device to improve cervical curve.

The patients’ MRA scans showed significant improvements in blood flow in the brain when they were lying on the orthotic with an improved cervical curve! The interesting thing is that it’s been known for years that a loss of cervical curve was associated with decreased blood flow in the brain, but there was no evidence showing that improving the curve would change blood flow. Now there is.

The effect of normalizing the sagittal cervical configuration on dizziness, neck pain, and cervicocephalic kinesthetic sensibility: a 1-year randomized controlled study.

While the previous paper is interesting, it’s limited by the small sample size and lack of controls. It was also a proof of concept study, and not one where an intervention was performed and tested to see if it made a difference long term. However, it may help explain why patients can get significant improvement in pain and dizziness.

This next paper features a randomized clinical trial of cervical curve correction along with cervical manual therapies compared to manual therapy alone for cervical dizziness.

The study looked at the results for patients with neck pain and dizziness for short term improvement at 10 weeks, and to see if they sustained improvement at a 1 year follow-up. The results are below.

Differences in patients with cervical dizziness at 10 weeks and 1 year. Changes after 10 weeks were similar to regular physical therapy, but the changes were hugely different at 1 year when there was an improved curve in the neck

The chart shows that the patients who were in the cervical curve correction group had significant improvements in head posture and curvature at 10 weeks, but the scores in pain and dizziness were pretty similar for both groups. Both groups got better, but they had similar improvements.

However, the changes at 1 year were impressive, and highlighted in red. While the control group had some regression into neck pain and dizziness, the cervical curve group maintained their symptomatic improvement much better. The mean improvements for both groups all crushed statistical significance, and the mean difference of the Dizziness Handicap Inventory (DHI) was by almost a whopping 30 points. That’s massive!

Does improvement towards a normal cervical sagittal configuration aid in the management of cervical myofascial pain syndrome: a 1- year randomized controlled trial.

A similar study was published on patients with persistent neck pain where physical manual therapy was compared to manual therapy and curve correction.

Just like the study involving dizziness, this paper on neck pain showed that both groups had similar improvements in scores on the Neck Pain Disability Index (NDI).

Changes in neck pain with manual thearpy and exercise alone vs manual therapy, exercise, and cervical curve restoration. Cervical curve patients were a little btter at 10 weeks, but were much better at 1 year follow up!

Again, like in the previous study, the 1-year follow-up is where things got interesting. The group that had treatment to improve their cervical curve had a much stronger ability to maintain their improvements in neck pain, while the control group started to return to their original pain scores. This was also largely statistically significant.

Long-Term Improvements Matter

So the big thing that changed my mind is that there is a growing body of work that supports the idea that creating structural changes in your cervical curve seem to help improve long term outcomes.

So while I still believe you can get significant improvement with or without a curve in your neck, your chances of maintaining your results over time seem to increase a LOT when you rehabilitate that curve.

Then you have the possible added benefit of improved blood flow to your brain, and that provides a potential bonus of better brain health.

Why Weak Muscles Are NOT the Reason Your Back Went Out

I’m a mega-proponent of strength training. It’s a major part of my life and it’s something I’ve always encouraged for my patients, family, and friends as a way to dramatically improve someone’s life.

That being said, strength training is an integral part of the treatment and prevention of musculoskeletal pain. There’s probably no condition in the world that has been widely attributed to a strength deficiency than lower back pain.

Got back pain? Must be those

  • Weak glutes
  • Weak transverse abdominus
  • Weak multifidi
  • Etc, etc

So now we have an entire world of fitness focused on preventing lower back pain by developing really intricate exercises to strengthen an unending list of muscles connected to the back.

Are Weak Back Muscles Really The Cause of So Much Back Pain?

I do believe that being sedentary, and the general weakness and de-conditioning associated with a lack of movement does put people at risk for low back issues. After all, being sedentary and de-conditioned is basically a risk for just about everything.

However, I do think that we need to re-evaluate why so many active and relatively strong people throw their backs out doing really slight movements.

What do I mean by that?

For many of the patients that have come to my office for chronic back pain, their stories don’t usually feature an attempt to lift something that was extraordinarily heavy. It’s generally things like:

  • I was reaching to grab my phone when I heard a pop
  • I was rolling out of bed when I felt something seize up
  • I was bending over to pick up a pillow when my back went out

Plus these people aren’t necessarily weak. These are people who can deadlift 400+ lbs or spend their day as construction workers lifting heavy things every day. I can promise you that these individuals did not have weak glutes.

So what might have happened?

The Principle of Coordination

All of the strength in the world is useless when the body is not prepared to make use of it.

Have you ever been to a bowling alley and picked up the wrong ball by accident? It’s a strange feeling. You may be accustomed to picking up a 9 lb ball, but the ball next to it was the same same color and shape but it weighed 14 lbs.

So you went to pick the ball up with the amount of force that you expected to easily lift the 9 lb ball, but your arm moves slower and you have to catch yourself for a second before reaching down and grabbing the correct ball.

Even though you are plenty strong enough to lift a 15 lb object without any problems, you were thrown off because your brain made a calculation wasn’t appropriate for the lift it was about to perform.

This takes a coordinated effort for your brain to tell your muscles to use the correct amount of force with the right timing in order to make lifting an object feel more effortless. It’s a really neat system when it works properly!

But if you didn’t know how much something weighed, and you went in without expectation, you would probably take a conscious effort to over-prepare your body to lift an object up so you wouldn’t be caught off guard. Your brain has plans and contingency plans for when it encouters an unknown situation.

So what does this have to do with your bad back? Your back is different from most of the other muscles in your body in that it is a muscle group that is almost always on. Your arm and shoulders don’t get used unless you need to perform a task. Your legs are always on when you’re standing, but they can be rested when you are sitting. Your spinal muscles only get a rest if you are laying down, which is a small chunk of the day for most.

Control of spinal movement is dictated by an intricate control system between the brain receiving feedback from the spinal muscles and joints, and commands to control it

This is an important concept because our spine has to move for just about everything. Even when you are lifting your arm or your leg, your brain is sending messages to your spinal muscles on how to move your spine to accurately perform an arm/leg movement.

When Coordination Fails

So we know that the spine is always on, and even when you are just trying to move any body part alone, your brain is still getting your spine prepared to brace or move in concert with other limb movements.

There is a lot of coordination that has to happen with this, and sometimes there are just moments in time where coordination will fail, and injury can occur in those small windows.

It wasn’t just an issue of being weak. It was an issue of timing that one part of your muscular system didn’t create a good enough response to protect the parts of your spine that may generate pain.

This doesn’t mean that you’re broken. It doesn’t mean that you need fixing. It means that when you’re active and putting your body under a steady dose of mechanical stress through exercise, sometimes things may get hurt.

It’s okay! Your body can heal, get better, and improve with time, especially when you have good alignment, flexibility, mobility, and appropriate rest.

Can Coordination Improve?

There are a number of things people can do to improve the coordination of your spine and nervous system. It involves making your spine more adaptable. So how can we improve our adaptability?

  • Respect your alignment and biomechanics. You don’t have to be obsessed about it, but dysfunctional spinal joints from structural shifting of the spine can decrease neurological coordination
  • Expose your body to different loading patterns. Perfect form in the gym is great, but your brain needs exposure to variation in movement so it knows how to deal with it in the future. Mix up your lifting and movement strategies
  • Train on different surfaces – You won’t always be on a nice flat gym surface when you have to lift something up. Perform movements and exercise on different surfaces to allow for your nervous system to adapt
  • Do reaction time training – reaction time training or rhythmic movements can train your body to work in different patterns and rhythms.

Why Am I So Off Balance?

A persistent feeling of being off balance can be one of the most disabling feelings a patient can have. Many patients who suffer with balance issues don’t receive proper examination and diagnosis, so they are left without many answers for treatment besides generic anti-nausea medications or herbal remedies like ginger.

In order to best take care of people with persistent balance issues, we have to understand why balance gets disrupted to begin with.

Normal Balance

We tend to think of balance as a function of leg muscles and joints, so we think of balance training as just standing on a Bosu ball or standing on one leg. We take balance fore granted because when it works well, we hardly have to think about it.

Truthfully, balance is the product of some complex calculations made by your brain based on 3 major senses. These senses are:

  • Vision from your eyes
  • Proprioception from your muscles, joints, and ligaments
  • Vestibular from the fluids in your inner ear

Your brain takes information from these 3 senses and compares it to information stored in your memory, experience, and context of your current situation and develops a strategy for how your muscles should fire to keep your body up right. It’s really pretty amazing when you think about all the moving pieces involved.

Even more unique is the fact that as far as mammals go, there aren’t too may of us that stand upright on 2 feet. Most of the animal kingdom stands on 4 legs so our brains had to develop differently from an evolutionary perspective than our mammal ancestors. The time it takes for our brains to develop this skill is one of the reasons why some mammals like start walking and moving right away, while humans take about a year to get to our normal mode of transport (standing/walking).

Being a father of a 1 year old has taught me a lot about how we develop balance by watching my little one learn to navigate that skill.

So you might think that your brain relies on all of these senses equally under normal circumstances, but in reality these senses are weighted differently. Here’s the breakdown:

Under normal circumstances, your brain prioritizes information from your joint and muscular system

So normally, an adult with healthy balance does rely on their muscles and joints (particularly in the legs and feet) or your sense of balance. That’s probably why things like weight training, yoga, bosu ball exercises, and more can strengthen the balance of people with normal functioning systems. All of those things really challenge and promote neural pathways to enhance your body position sense.

But what happens when our senses starts to decline?

Balance Fails: When Senses Break, When the Calculator Breaks

If one of our senses starts to struggle, your brain has to weigh your senses differently. We can actually test this in our office by performing balance tests in different sensory circumstances. For example, if we have you stand on an unstable surface, your brain puts more emphasis on your inner ear and vision because the unstable surface is giving your brain constantly changing information that makes it hard to rely on.

The good news is that your brain is great at compensating when one sense goes down. Losing one inner ear to infection is a problem that most people can recover from and regain normal function. Usually patients that still suffer from balance issues after loss of one inner ear respond really well with vestibular rehabilitation to re-compensate the patient’s brain.

The bad news is that when multiple senses aren’t working well, it makes it really hard to make up the difference. Losing both inner ear systems from infection or Meniere’s can permanently alter your balance. The same thing can be said for having neuropathy in both feet or having a ocular misalignment in both eyes. For these types of issues, people can only hope to compensate as best as they can for permanent deficiencies.

The other possibility is that the brain itself takes an injury like a concussion or stroke disrupt the brain’s ability to make calculations. This is especially true for injuries related to the brain stem or cerebellum which are major centers for balance control.

The good news is that many of these problems can be improved with chiropractic and neurorehabilitation.

Targeting the Correct Body Parts

We often see a lot of patients with movement and balance issues after they’ve been to several other doctors and specialists. One potential pitfall is that many specialists have one area of focus which creates a conundrum commonly seen in medicine.

When you have a hammer, and you’re great at hammering, everything looks like a nail

There was a point in my practice where every balance problem that came in to my office was a problem in the neck, and we did really well with most patients!

We still address the neck as a primary problem in most patients, but working with more and more patients with balance issues and dizziness, we have taken a step back so we can see the whole picture.

Having a new perspective on patients by looking at balance as a function of the brain has helped us improve outcomes with challenging balance issues.

The first step is performing a thorough exam, not just on the neck, but on the visual, vestibular, and somatosensory system to identify how this problem might be addressed best with a personalized program of neurological rehabilitation.

How to Tell if Migraines are Coming from Your Neck

A recent systematic review in the prominent journal Headache showed that spinal manipulation could have an effect on headache days and pain intensity in patients with migraine headaches. While this is old news to many practicing chiropractors, this is one of the first instances that a major headache journal has acknowledged that manipulation could have a legitimate positive effect in patients suffering with migraines.

When it comes to migraine headaches and chiropractic, there’s a big gap in knowledge between what clinicians see in the field everyday and what the published literature says about our effectiveness. The published literature has generally shown that chiropractic might be good for tension headaches, but clinical trials on migraines have suggested that it’s not significantly better than placebo.

On the other side, patients with migraine headaches are often our most successful cases in upper cervical chiropractic. It’s not even that we tend to be just a little bit successful with chronic migraines patients, many of us expect these 85-90% of these patients to get a lot better in a matter of weeks. It’s usually not the easy migraine patient that comes into our offices either. Typically people don’t find an upper cervical chiropractor until they’ve tried a wide variety of treatments and medications.

So what gives? Why is there such a gap between private practice and published research?

I believe there’s 2 main reasons:

  1. Most spinal manipulations done in research have used non-specific contact, general manipulation of the neck, where as upper cervical techniques use a very precise and targeted force to one part of the neck. To date, there are no clinical trials investigating migraine headache and upper cervical work. (But this is a soap box for another day)
  2. Previous clinical trials haven’t done a great job in identifying patients that have the signs of a cervical spine dysfunction.

Identifying Cervical Spine Dysfunction in Migraine Patients

One of the most important things we do during a Complimentary Consultation is to figure out if you’re a good candidate to respond to the type of chiropractic we perform in our office.

While getting your spine corrected is healthy in of itself and anyone could benefit from it, I only take on cases that I believe can significantly improve your quality of life. In order to do that, I always screen patients to make sure that I am going to have a high likelihood of success in helping you reach your goal.

In the case of a migraine patient, we are looking for clues that tell us that your migraine symptoms are primarily being generated by the neck. Migraines can have different causes:

  • Some have a biochemical issue in the brain and may benefit from something like a ketogenic diet.
  • Some have a higher hormone component and need to be addressed by modifying the endocrine system
  • And many have a major cervical spine component

How can you tell if it’s coming from the neck? Beyond just looking for neck pain, here are some major clues that have been identified in migraine research:

  1. Worse ability to turn their upper neck side to side – A test of upper neck rotation called the flexion rotation test has been shown to be more asymetrical in some migraine patients compared to normal controls [Source]
  2. Decreased sensitivity to 2 point discrimination in the upper neck – A study showed that migraine patients have decreased ability to differentiate between 2 points when applied to their neck. [Source]
  3. Increased pain and tenderness in the upper neck – patients with cervical spine issues show increased tenderness to touch in their upper neck. It becomes even more significant if pressing on a sensitive area recreates the pattern of head pain [Source]

Can The Neck Be Fixed?

A 2015 study looked at the effects of an atlas realignment in patients with chronic migraine headaches. The study showed that a gentle correction to the upper neck showed significant improvements in headache days and quality of life in migraine patients over the course of 8 weeks.

We rely on 3 big factors for improving the neck.

  1. We need to see a structural change in the biomechanical alignment of the neck after an atlas correction.
  2. We want to see a global change in posture in response to correcting the alignment of the neck
  3. We want to see a change in the tenderness of the muscles and nerves stemming from the upper neck. Just as we saw that those tender spots predicted migraine, when we feel those tender points subside right after a correction, it’s a strong marker that we are on the right track.

While we can’t fix everyone, there’s a large segment of the migraine population that would do well with this form of care, but we have to make sure we identify the right candidates.

New Study Examines the Effect of Chiropractic on Patients with Previous Stroke

The effects of a single session of chiropractic care on strength, cortical drive, and spinal excitability in stroke patients.

Scientific Reports 2019

Holt K, Niazi IK, Nedegaard RW, et al.

Full Text


A research team based out of the New Zealand College of Chiropractic who have been publishing a great deal on the neurophysiologic impact of chiropractic on the brain did an investigation on the impact of chiropractic adjustments on patients who have previously suffered a stroke.

The study was set up as a randomized controlled crossover trial of 12 patients with a previous history of stroke. For the first week, half the patients received an adjustment while the other half had a control maneuver of just moving the body around. Seven days later, the groups switched with the control group getting an adjustment and the intervention group getting a control.

The authors tested patients who suffered weakness in their ability to plantar flex post stroke and tested their strength on plantar flexion pre and post adjustment.

They also wanted to know if there were increases in strength, were they likely tied to a local spinal cord mechanism, or did the strength change come from the brain. To do that, they used electrodiagnostic testing to measure things called the H-Reflex and the V-Wave.

The H-reflex uses an electrical stimulation of a peripheral nerve (the tibial nerve in this case) during a sub-maximal contraction to measure excitability in the spinal motorneuron pools (influenced at the spinal cord level)

The V-Wave uses electrical stimulation during maximal contraction to measure recruitment of additional neuronal pools which is an indicator of cortical drive (influenced by the brain)

If you want to get into the weeds on these tests, you can read this paper here.

There were large and significant changes in maximum contraction of plantar flexion post adjustment while the control group showed a decrease in strength.

As far as the electrical diagnostic testing, the chiropractic group showed large and significant changes in the V-wave indicating that the strength change was likely from a brain mechanism (cortical drive).

For the H-Reflex slight change in the adjustment group that was not significant. There was also a slight decrease in V-wave change in the control group that was also not significant.

Dizziness and the Cervical Spine: Beyond Cervicogenic Dizziness

Read Time: [6 minutes]


The cervical spine has been a known source of dizziness since the 1950’s with a classification as cervical vertigo. While the true spinning sensation of vertigo is not common with cervical spine issues, a feeling of imbalance, disorientation, light headedness, swaying, and unsteadiness have all been linked to problems in the cervical spine, especially the craniocervical junction.

Cervicogenic vertigo has a contentious history as a legitimate clinical entity. This stems from the fact that cervicogenic vertigo has no distinct biomarker and remains a diagnosis of exclusion; a leftover diagnosis when a more obvious inner ear cause doesn’t exist.

Cervicogenic vertigo may or may not exist as it’s own unique clinical entity, but there’s little doubt that the cervical spine plays a key role in balance and equilibrium. In this article, we’ll talk about how a dysfunctional cervical spine can be causing dizziness, and how cervical spine interventions can be a useful therapeutic option for people with dizziness disorders of many types.

The Anatomy of Cervicogenic Dizziness

While the diagnosis of cervicogenic vertigo has been contentious, the anatomical connections linking the cervical spine to symptoms of dizziness are not.

Neck Muscles, Ligaments, and Joint Receptors

The neck is loaded with receptors that help the brain know where the head is in relation to the body. These receptors come from the small suboccipital muscles, the cervical discs, the cervical joints, and the cervical ligaments. The receptors from the suboccipital muscles in particular have an unusual amount of density when compared to the rest of the spine [Source]. When you move your neck, these receptors help to control how fast and how far you move your neck. They are also receptors that are very active even if your head isn’t moving because we spend most of our time with our head up fighting gravity. All of these signals are transmitted to the brain which has to make constant decisions about where to put the head next.

Image result for upper cervical spine ligaments and muscles

When you have an injury like a whiplash or head trauma, the muscles and ligaments of the neck are susceptible to injury, and that injury takes away one of the methods that your brain uses to keep track of the head. If your brain can’t tell where your head is in space, then dizziness and a sense of imbalance is the result.

Cerebellum and Vestibular Nuclei

The cerebellum and vestibular nuclei are 2 really important parts of the brain that play a role in dizziness and balance problems originating from the neck.

The vestibular nuclei is the routing center for the signals traveling from your inner ear through the vestibular nerve. The primary job of the vestibular nuclei is to take the information coming from your ears and to calculate where the head is in space and to move the eyes appropriately in response to these signals. While the bulk of the input into the vestibular nuclei is coming from the ears, the vestibular nucleus also receives afferents from the cerebral cortex, visual centers, spinal cord, and cerebellum. It takes in all of this information and calculates where the head is in space based on what you see (visual), head direction (inner ear), and proprioception (muscle and joint activity).

Image result for cerebellum and vestibular nuclei

The cerebellum is generally thought of as a subdivision of the brain that aids in coordination of muscle movements. However, the cerebellum has an large chunks of real estate devoted to eye movements and modulation of the vestibulo-ocular response. The cerebellum also plays a role in how the vestibular system impacts the spinal muscles via the vestibulospinal tract.

These regions of the brain are important because the same muscles, ligaments, and joint receptors we discussed earlier have direct and indirect connections to the vesibular nuclei and the cerebellum.

The Vertebral Artery

The vertebral artery passes through the transverse foramina in the cervical spine. At the level of C1 and C2, the vertebral artery takes on a more tortuous path into the skull to supply the brain stem and cerebellum with oxygen. Most clinicians think of the vertebral artery as a potential source for arterial dissection that can cause stroke. However, there are documented cases of transient vertebrobasilar insufficiency caused by rotation of the neck. This syndrome has been named Bow-Hunter Syndrome or rotational vertebral artery vertigo (RVAO). [Source]

Studies have shown that decreases in blood flow from the vertebral artery can cause transient ischemia through the vertebral artery when the neck is turned in rotation. It’s not known whether the ischemia is affecting the brain stem/cerebellum, or if the ischemia is hitting the labyrinthe itself because of the way the artery branches out toward the peripheral vestibular apparatus.

Beyond Cervicogenic Dizziness

Therapies for the cervical spine can make an impact on cervicogenic dizziness. These therapies can commonly include cervical exercises, osteopathic manipulation, upper cervical chiropractic approaches, and other manual therapy techniques. The use of these modalities has largely been associated in patients who have reported dizziness following a trauma to the neck such as whiplash disorder [Source].

Is there a role to play for cervical spine-based therapies for other causes of dizziness and imbalance?

While there’s limited evidence to pull from, there are numerous anecdotes and case reports of patients with motion sickness, Meniere’s-like illness, and vestibular migraine showing improved outcomes while receiving care focused on addressing cervical spine dysfunction.

Let me be clear, I have no supporting research to support what I’m going to say next. These are just observations from 8 years of working with dizzy patients.

Many patients with feelings of dizziness but do not have full peripheral vestibular loss likely have problems of central processing of sensory information. Plastic changes in the central nervous system that can promote a sense of dizziness can include:

  • Inapporpriate Sensory re-weighting for balance
  • Inappropriate afferentation into the vestibular nuclei and cerebellum
  • Anxiety related to pathologies or activities that promote dizziness
  • Decreased cellular activity in key sensory areas of the brain due to disrupted hemo/hydrodynamics

Simplified flowchart showing the way sensory information contributes to balance

By understanding some of the interconnected nature of the senses that produce a feeling of balance, we can leverage treatments to create neuroplastic changes in the central nervous system that may help a person adapt when vestibular function is compromised.

When it comes to dizziness, there are so many anatomical players and varying degrees of compromise, we can’t rely on one thing to fix all types of dizziness. By using the cervical spine to help stimulate the proprioceptive system, we might be able to help some patients compensate with a deficit where they weren’t able to before. We may also be removing one extra stressor to the balance system that was preventing the body from compensating appropriately.

The Downside of Listening to Your Body Too Much

Historically I’ve been a big advocate of being “in-tune” with your body. For the most part, I do think that a generally healthy person can benefit from developing a better awareness of what their body is experiencing. It’s a good guide for adapting your training and developing a meditative practice like breath awareness.

In recent years, I’ve come to the conclusion that there are situations where a patient can be TOO in-tune with what their body feels, and this perception of what their body feels can actually create fear, apprehension, and further harm to their mental state and quality of life. Today we’ll discuss some of these types of situations and what a patient can do to help themselves break a negative connection with their own self-awareness.

When Listening to Your Body Goes Wrong

There’s a lot of research that shows that paying attention to inner body activities can be extremely beneficial for you. Things like being aware of your breath, meditation, counting your heart beat are all tools used in yoga and mindfulness practices that really help people a lot!

The concept of listening to your body has been popularized in the circles of fitness. It’s a phrase used to guide people in sport or exercise to recognize when their body may not be in the best state to complete a task.

It involves feeling out different aches or pains, observing where the body seems to be putting a restriction on movement, or just an inner awareness of fatigue. It’s supposed to be a guide against overtraining and possibly develop an awareness of impending injury. In cases where this is an otherwise healthy person with no history of chronic pain problems, it serves a good purpose.

However, in my experience seeing patients with chronic pain daily, a heightened attention and awareness of their own pain can be very counterproductive to a patient’s recovery and progression. Let’s talk about why.

Being In-Tune With Body Pain

It’s natural for your brain to pay attention to areas of your body that are in pain. It’s one of the ways your body protects itself whenever it has suffered an injury like a sprained ankle or a large cut on your hand. By avoiding contact of the injured body part, you are allowing your body to temporarily immobilize an area so that the natural healing responses can have time to fix the damaged tissue.

This is a necessary and completely normal response to physical injury. While this is a big generalization, the healing time for various tissues is shown in the graphic below. You can see that most minor muscle and ligament injuries can take a few days to heal while moderate to severe injuries can take several months.

Image Credit and Instagram @drcalebburgess

So even in a worst-case scenario where you have an unstable injury that needs surgery, it takes about 2 years for a tissue to heal completely. If we know that these are the general healing times for people, then what explains the pain patients can feel for several years?

However, for some people there can be problems that develop in neurological pathways that perceive pain. What seemed like a simple, straight forward injury leads to chronic or persistent pain that lasts long beyond the normally allotted time for tissues to heal.

The problem in these cases is that many of these patients will avoid movements or activities to protect an area of injury that may not need protection and avoidance. So there ends up being a cycle of injury, stopping exercise, followed by deconditioning from lack of exercise leading to more risk of injury and pain.

The brain can learn to fear movement to avoid pain creating a vicious cycle often seen in persistent pain patients.

This is the result of treating the pain issue as a muscle or joint problem, when it’s really a brain and neurologically rooted problem. The kicker is that while avoiding movement is necessary for true joint injuries, avoidance may actually make a persistent pain problem in the brain even worse.

Many times when someone suffers with persistent pain issues that have no diagnosable injury, being too aware of your body’s painful triggers can be detrimental to healing and recovery.

Pain Science

One of the more popular concepts in pain science is the idea that chronic pain can develop from factors known as hypervigilance, catastrophizing, and fear-avoidance.

  • Pain Hypervigelance – “when there is an excessive tendency to focus on pain or somatic sensation, or an excessive readiness to select pain-related information over other information from the environment.” [1]
  • Catastrophizing – “an concept where people show exaggerated thoughts and descriptions of the negative consequences of pain featuring magnification, rumination, and helplessness” [2]
  • Fear-Avoidance – a model of chronic pain that describes how people develop and maintain chronic pain as a result of attention processes and avoidant behavior based on pain-related fear. [3]

Those are nice academic definitions, but what do they mean for us? A lot of it comes down to being really fixated on how bad the pain is and avoiding anything that might be associated with the pain. And we now know that the fixation and avoidance behavior can reinforce maladaptive patterns in the way the brain is working.

So it is to say that being too focused on your pain when you are trying to heal can reinforce the cycle of staying in chronic pain.

Fostering an Anti-Fragile Mindset

One of the big things that drew me to chiropractic was a philosophical idea that the body is strong and has a remarkable ability to heal itself. It’s a mindset that I’ve had growing up while playing sports where my coaches would see someone get injured and they’d always say to just walk it off.

Obviously it’s not something you want to do with an unstable or serious injury like major sprains or a concussion. However, for things like scraping our shins, getting hit by a pitch in the back, pulling a muscle, or having a mild ankle sprain this approach trained our young minds to:

  • Understand that the pain will go away on it’s own in time
  • That our body and mind is strong enough to will away pain
  • That we aren’t fragile

Ultimately, we came away with the mental state that we will feel better and pain goes away with time. This also meant that we were pushed towards our normal activities as quickly as possible.

As a chiropractor, a big part of my job is to foster a sense of strength and resiliency in my patients. It means that I want my patients to foster a sense of independence from their pain. That means I don’t want my patients to fear doing activities or to be dependent on any intervention whether that’s a drug, massage, or even chiropractic adjustment. I want my patients to never need me, but they can certainly count on me to be there when they want to be better.


So before anyone takes my points to the extremes, let me just say this.

  • Mental state won’t cure every pain
  • Don’t avoid doctors, especially with serious injury/illness
  • Many people will still have chronic pain even without a sense of fear avoidance and catastrophizing.

So with that out of the way. Mental state can be a powerful influence on the development and resolution of pain, but it can be really, really difficult. When we know there no longer a risk of worsening an injury, in order for patients to make the next step in their recovery, we have to engage them in doing the normal activities that they have avoided.

That might mean lifting some moderately heavy objects, bending their back forward, turning their heads, or getting back into exercise. Yes, sometimes that means we have to make patients revisit their pain and forcing their brain and nervous system to adapt and stop fearing it.

It means they have to stop listening to their body for a bit, and actually push through the false alarm signal so they can adapt.

It’s not easy, and it doesn’t happen quickly. But when patients are able to get their, the whole world opens up again, and we can start to pop the bubble that they’ve lived in because their brain is free again.

Exploring the Gut-Brain Connection through the lens of concussions

It’s no longer a secret that the composition and health of your gut has an substantial impact on the health of the brain and nervous system. Research on the role the gut microbiome has exploded in the last 10 years with blockbuster studies showing that your gut bacteria composition can affect mental health conditions like depression [1] and neurological disorders like Parkinson’s Disease [2].

Although chiropractic is generally associated with bad backs and tight muscles, most chiropractors have a deep seated interest in the connection between the brain, the immune system, and the gut. While there haven’t been any hard studies on the topic, some authors are looking at this connection to see if the gut-brain axis may be a link between head injuries and neurodegenerative disease. This specific topic actually ties into all of my scientific interests in one shot, so you’ll hopefully get a lot from some of the extra content and diagrams I’m going to try to lay out in this article.

A Tale of Two Brains

Most everyone is aware of the importance of the brain in your head, but there is also a staggering number of neurons that exist in your gut. This bundle of nerves in the gut is collectively known as the enteric nervous system (ENS). There are an estimated 500 million neurons in the gut which exceeds the number of neurons in the spinal cord, and makes it the second only to the brain in terms of neural density. This has lead some scientists to affectionately call the ENS the 2nd brain, so maybe making “gut” decisions might not be such a terrible thing (jk).

The number of neurons in the gut might actually be the second most interesting thing about the ENS. The most interesting thing is that the ENS can actually function without talking to the brain if it needs to. The gut has it’s own set of interneurons and integrating centers so that it can carry out reflexes and functions without the help of the brain. In normally functioning humans, the brain does talk to the gut through the vagus nerve, but the vagus nerve can be severed and the gut will continue to work of it’s own power.

The gut is also a MAJOR producer of neurotransmitters for the body which are the chemical currency of the nervous system. The gut produces about 90% of the total serotonin in the body and about 50% of body’s dopamine which can have major implications in the function of the brain and mood [3]. We’ll get into the importance of that a little later.

Shield’s Down: The Gut and the Brain Barrier

The brain and the gut also has some similarities in that both have physiological barriers that have been topics of high interest for neurodegenerative disease. 

The gut has a barrier that keeps potentially harmful substances from getting IN to your blood stream while the brain has a barrier to keeps harmful substances in the blood OUT of the brain.

The barrier in your brain is called the blood-brain barrier and it’s fairly well established that disruption of the blood brain barrier is associated with a host of neurological disorders [4]

Intestinal permeability, also known as leaky gut, is also well supported in the literature as a driver of systemic inflammation, but has been subject to a lot of abuse from various practitioners overstating it’s prevalence and significance. While not everything is leaky gut, and not every leaky gut needs an intensive supplement regiment, intestinal permeability is a real phenomenon has the potential to create disease in the gut like Celiac, inflammatory bowel disease, and metabolic syndrome. [5]

Losing these barriers is like losing a layer of defense which can make your body more prone to attack from disease causing agents, or even the cells of your own immune system.

Neuroinflammation – Collateral damage from your Body’s Defenses

So we have these barriers in our gut and our brain that help prevent harmful substances from getting into our blood or into our brains. We know that when these barriers get disrupted that our body is more susceptible to threats from outside the body. However, the increased permeability of these barriers may be the major driving force in threats from the INSIDE of the body.

Our immune system is made up of several classes of white blood cells and proteins that patrol the body looking for any bacteria, viruses, parasites, fungi, or other organisms that may potentially harm us. While the immune system does a remarkable job protecting us, scenarios can arise when the immune system accidentally does the body harm. This is the case in autoimmune disorders like multiple sclerosis, rheumatoid arthritis, Grave’s Disease, and Crohn’s Disease.

The presence of these autoimmune reactions can be the result of an immune system that is isn’t regulated properly or has accidentally built antibodies that can inadvertantly attack the body’s own tissues. When you have a leaky gut, these immune cells can get primed to attack compounds that don’t normally harm the body (think gluten or food allergies). When there is a leaky blood-brain barrier, these immune reactions can occur in the brain and spinal cord which normally tries to keep inflammation OUT. When these reactions occur in or around the brain, it can cause neuroinflammation which can gradually deteriorate brain tissue. Some authors have suggested that post-concussion syndrome may be a form of an inflammatory brain illness, but that hypothesis hasn’t been studied extensively yet. [6]

It is something that’s worth paying attention to because many neurodegenerative disorders seem to have a link to the brain being exposed to chronic neuroinflammation, and surely chronic traumatic encephalopathy would fit that bill.

Microglia: When the Brain’s Helper Cells Go Rogue

Your brain is loaded with non-neuronal helper cells called glia. Glia help support the neurons in your brain by providing protection, insulation, and repair whenever it needs. They take up a huge chunk of brain material and actually outnumber neurons in the brain by a factor of 10.

A special type of glia exists in the brain called microglia. Microglia are macrophages inside of the brain and they help clean up dead or unnecessary debris hanging out in the brain. They play a role in protecting the brain from infections, but they also do really cool things like prune synapses that aren’t used anymore, or get rid or clean up dead brain cells after injury. [Source for graphic and summary]

Microglia can act as cells that just keep watch inside the brain, but primed and activated microglia are looking for a fight and can stimulate inflammation.

Like most immune cells, their default setting is turned to the off switch. You don’t want immune cells overly active otherwise they create a lot of inflammation. When infections or injuries arise, these cells become primed and active to help initiate the clean up and repair inside the brain.

This means that they start eating away at dead cells and recruiting other immune cells to create inflammation. Short-term inflammation is essential to healing, so we need these cells to generate inflammation for short periods of time while tissues heal. But sometimes, when a cell gets turned on, the off switch gets broken and it stays on leading to chronic inflammation.

Chronic activation of microglia has been implicated in multiple neurological diseases with autism, MS, and Alzheimer’s Disease chief among them. [7]

The Vagus Nerve – The Bridge for the Gut-Brain Connection

If you’ve been following this blog for a while, you know that I love writing about this cranial nerve because it appears to be relevant in all aspects of our health. You can comb through my previous thoughts on the vagus nerve here.

The vagus nerve provides a two-sided highway for the brain to access the gut, and for the gut to access the brain.

The vagus nerve is a specialized nerve that comes off the brain stem and is connected to many of the body’s vital organs. It has a particularly important role in the gut-brain axis because it is a primary conduit for the brain in your gut to talk to the brain in your head.

This becomes really important when we consider that the brain acts as a biological thermostat for multiple functions in the body, including regulation of the immune system. It’s been well established that changes in the your gut bacteria can dictate inflammation in the brain [8] and brain damage can influence gut permeability [9]. Many scientists suspect that the vagus nerve is a central player in these phenomenon.

How important is this bridge? Some evidence suggests that the vagus nerve may be a conduit for how rogue proteins in Parkinson’s Disease can spread into the brain.

Concussions: Disrupting the Barriers and Stirring the Pot of Inflammation

So now it’s time to put it all together. How does something like a concussion affect this entire system? Two recent review papers have gone into this concept with some detail, but here are the big ideas [1011]:

  • Traumatic brain injury (TBI) can cause dysautonomia resulting in poor functionality of the vagus nerve and poor motility of the gut.
  • Animal models have shown that experimentally induced brain injury can lead to more porous gut permeability within 3 hours of TBI.
  • TBI disrupts the blood brain barrier
  • TBI will lead to priming of microglia and neuroinflammation. Structural signs of brain injury are correlated to the amount of microglia primed in the brain
  • A disrupted gut lining after TBI is more susceptible to rogue bacteria infiltrating the blood stream and creating systemic inflammation. Systemic inflammation can further impact the brain’s microglia promoting more neuroinflammation long after TBI.

In a worst case scenario, the disruption of the gut barrier and the brain barrier allow for a persistent cycle of systemic inflammation and constant activation of brain microglia.

Image from Sundman et al. Brain, Behavior, and Immunity (2017)

Do we know if this happens in humans yet? Truthfully the answer is no. There haven’t been any experiments done that have looked at this relationship yet so it’s too early to say if this is a real phenomenon that can tie together brain injury and neurodegeneration.

So what probiotic should I take after a concussion?

So the natural question after reading this is what type of treatment do you need after a concussion? When we talk about guts, the usual line of thinking is to think about probiotics, but that probably won’t lead us to the answers people with brain injuries really need.

Remember that big cast of characters we talked about before we addressed the topic of concussion? Here’s a refresher:

  • The brain
  • The “brain” in your gut (enteric nervous system)
  • Intestinal barrier
  • Blood-brain barrier
  • Microglia
  • Vagus nerve

Brain injury is a multi-faceted injury that has wide effects on numerous parts of the body. There’s no magic potion that will specifically hit everything in a positive way. Here are some ways we’ve seen patients improve with problems in the gut-brain axis:

  • Cervical, vestibular, ocular rehabilitation with graded exercise is becoming the gold standard in concussion recovery
  • Cardiovascular exercise to improve hippocampal and global neuroplasticity
  • Correction at the craniocervical junction to improve cerebrospinal fluid dynamics, decrease stress on the blood brain barrier, and improve circulation of neuroinflammatory compounds
  • Vagus nerve stimulation to improve neuroplasticity, decrease systemic inflammation, and increase gut repair
  • Neurofeedback for plasticity and improve parasympathetic tone
  • Pre- and probiotics to repair gut permeability
  • Ketogenic/fasting type diets to decrease neuroinflammation and alter gut biome
  • Reduction of common dietary gut irritants

There’s a lot more that we could add to this list, but these are some of the most common things that we see that can help some of the more challenging patient presentations.

Will these therapies stop or prevent neurodegenerative diseases? We can’t say for sure, but they are all things that tend to improve the lives of people with early signs of neurological deterioration so time will tell if this can impact the brain injury population as a whole.

  1. Marin I, Goertz J, Ren T et al. Microbiota alteration is associated with the development of stress-induced despair behavior. Scientific Reports. 7 Article number: 43859 (2017)
  2. Sampson T, Debelius J, Thron T, et al. Gut microbiota regulate motor deficits and neuroinflammation in a model of Parkinson’s Disease. Cell. 2016 Volume 167, Issue 6.
  3. Stroller-Conrad J. Microbes Help Produce Serotonin in the Gut. Cal Tech Matters Newsletter. April 9, 2015.
  4. Zlokovic BV. The blood-brain barrier in health and chronic neurodegenerative disorders. Neuron. 2008 Jan 24;57(2):178-201.
  5. Bischoff SC, Barbara G, Burrman W, et al. Intestinal permeability – a new target for disease prevention and  therapy. BMC Gastroenterol. 2014 Nov 18;14: 189.
  6. Rathbone, AT, Tharmaradinam S, Jiang S, et al. A review of the neuro-and systemic inflammatory responses in post concussion symptoms: Introduction of the ‘post-iflammatory brain syndrome’ PIBS. Brain, Behav. Immun. 46, 1-16 (2015).
  7. Streit WJ, Mrak RE, and Grifften WST. Microglia and neuroinflammation: a pathological perspective. Journal of Neuroinflammation. 2004
  8. Fung TC, Olson CA, and Hsiao EY. Interactions between the microbiota, immune and nervous systems in health and disease. Nature Neuroscience 20, 145-155(2017).
  9. Crapser J, Ritzel R, Verma R, et al. Ischemic stroke induces gut permeability and enhances bacterial translocation in aged mice. Aging. 2016 May;8(5):1049-63.
  10. Zhu CS, Grandhi R, Patterson TT, Nicholson SE. A review of traumatic brain injury and the gut microbiome: insight into novel mechanisms of secondary brain injury and promising targets for neuroprotection. Brain Sci. 2018 Jun; 8(6):113.
  11. Sundman MH, Chen NK, Subbian V, and Chou YH. The bidirectional gut-brain-microbiota axis as a potential nexus between traumatic brain injury, inflammation, and disease. Brain Behav Immun. 2017 Nov; 66:31-44.

1 rep max squat: a future biomarker for brain health?

When people think about growing new brain cells and optimizing brain health, they think about playing games like Sudoku or Luminosity. The idea being that we need mental games to flex our mental muscle.

The problem is that mental games like Sudoku and Luminosity have failed to demonstrate any meaningful evidence that it alters brain or cogntive function. They can make you good at Sudoku-related tasks or LUminosity-related games, but that’s about it.

There is one thing that has consistently shown improvements in cognitive, cellular, and neurological measures of brain function:


A 2018 study showed that the dis-use of leg muscles was associated with decreased production of neural stem cells and decreased maturation of the supporting cells in the brain.

While this study was done in rats, it does help to explain some important phenomenon seen in humans.

Neurodegenerative Disease, Leg Exercises, and Stem Cells

Neurodegenerative diseases consist of brain and nervous system illnesses like multiple sclerosis, Parkinson’s Disease, an ALS. One of the big commonalities with this class of neurological disorders is that they they will eventually take away your independent ability to move.

Dr. Danielle Botaii, one of the authors of the study, wanted to investigate whether it was the gradual deterioration or the nervous system compromised muscular function, or if there was a possibility that loss of mobility from these diseases accelerated brain deterioration. [Source]

The study used mice and restricted the use of their hind legs and were compared to control mice who roamed normally. The researchers found that the mice who didn’t have normal use of their legs showed:

  • 70% decrease in neural stem cells compared to controls
  • Decreased maturation of support cells in the brain
  • Decreased expression of key genes for mitochondrial health

All of this to say that simply taking away the function of their legs could have significant ramifications for the ability of the brain to develop, adapt, and repair properly. With compromised stem cell production, less glial cell maturation, and worse energetics, you deal the brain a harder hand to play with. So much of our brain is built to provide action and resistance to gravity, and your legs play a huge role in that.

Squatting Your Way to a Better Brain

So the title of this article was definitely hyperbolic and click-baity. Guilty as charged. But the idea of squatting your way to better brain health sounds pretty sexy when you’re a doctor that lifts.

Working on that Snatch/Overhead Squat…..for brain health purposes

It’s super unlikely that your 1 rep max squat is going to be useful as a brain biomarker (though one can hope!), but there’s growing evidence that moving your legs frequently and often is phenomenal for your brain. One might even be able to make the case that running, jumping, squatting, and any other movement that keeps your legs strong may have more brain benefits than weight loss benefits.

There’s been ample evidence in mouse models that showed steady state running had significant effects on brain cell growth in a key memory area of the brain called the hippocampus. There’s also been compelling studies showing sedentary behavior reduced brain volume in parts of the brain which couldn’t be overcome by casual exercise.

There’s really no human evidence yet that shows that squatting will change the brain, but I feel strongly that preserving leg strength is one of those key things that differentiate those that age poorly and those that age with grace.

It’s definitely way too early, but I say we jump start the movement to 1RM for your Brain and let the evidence come in after the fact. Squat regularly and squat often friends.