Functional Neurology through a Chiropractic Specific Lens

To some, functional neurology is somewhat outside the chiropractic modality. To others, it is central to everything we do. When a recent article hit the Journal of Chiropractic and Manual Therapies, alleging that there was no evidence for the effectiveness of functional neurology, it provided an opportunity to reflect on common misunderstandings that surround the practice of functional neurology. We’ve already taken a look at the actual state of the evidence. Now it’s time to take a look at it from a chiropractic specific perspective.

Dr Michael Hall, of Brain DC fame, is very much embedded in the chiropractic and functional neurology space. His commentary on this topic touches on some valuable points, and peers more deeply into the chiropractic-specific aspects of the FN approach:

“First of all we need to know what functional neurology is,” he says. “It’s not a technique. It’s not its own discipline. That has kind of been bastardised. Chiropractors have always been about the nervous system. We have always been about removing subluxation to improve performance and the function of the nervous system. So in that way, we’ve always been functional neurologists. “Is there research that says the chiropractic adjustment lowers blood pressure? There is. That’s functional neurology and it’s well referenced. Is there research that says the chiropractic adjustment affects the prefrontal cortex (i.e. Heidi Haavik’s work) or impacts brain plasticity? Is there research that says the adjustment reduces pain? There is. That’s functional neurology. In rehab, there’s a plethora of articles that talk about removing joint dysfunction before any muscle activation. That’s functional neurology. Whenever chiropractors make an adjustment to the spine, there is an impact on the nervous system from a functional perspective.”

We’ve seen these things set out in research, but they are not usually branded functional neurology. It is simply chiropractic care juxtaposed with issues like hypertension, brain plasticity or pain. The terminology might not be there, but the functional approach clearly is.

Hall is emphatic in his argument that it is inappropriate to try to identify it as its own technique, but that basic science and an understanding of what chiropractic is and does holds the key to understanding what functional neurology means in a chiropractic-specific way. Hall explains that there is a functional neurology aspect to the adjustment, but also that when we recommend lifestyle changes (like exercise) we are recommending something that fires the brain. If we know our basic science, and if we skill up in the area of functional neurology, we can add value to everything we do.

“[Exercise] is not about your pulse or your heart rate. It’s about activating your brain. Exercise doesn’t lower blood pressure. It stimulates receptors in the nervous system, that then control the heart. You see, we keep having this end organ discussion. We talk about salivary cortisol and the adrenals. We talk about exercise and blood pressure. When you move around and exercise, you are firing the frequency of neural pathways that then increases your vagal tone. Your vagal tone is what slows down your heart rate, alleviates your adrenal exhaustion, improves your acid reflux, and reduces SIBO (small intestinal bacterial overgrowth)

This begs the question, “What is chiropractic?” Is it simply removing subluxation?

“This is where the ASRF comes in,” says Dr Hall. “[Chiropractic] is changing the function of the nervous system through the adjustment. If I can adjust you, I can increase the firing of afferent pathways. What we do know through Haavik’s work is that the adjustment of the spine affects the frontal lobe. Basic science research says that frontal lobe projects down to Pontine mid-wave centres that are inhibitory to the cardiopulmonary system. How does the adjustment lower blood pressure? The adjustment fires through Frontal Pontine pathways to inhibit the rostral IML. That is functional neurology.”

Hence, even if we don’t understand the finer points of what happens throughout the nervous system when we remove vertebral subluxations and empower patients to move towards healthier lifestyles, functional neurology is in everything we do.

Still, somehow we have been moving the focus to end organ conversations so our patient can understand it. In doing so we risk getting caught in a symptoms-based model and becoming reductionist both in our thinking and in the way we practice.

The Keys That Lie in Knowing Basic Science

Perhaps the term “basic” science is a misnomer, given the complexities of how brain and body interact. When you can follow the nerve connections, and track how the brain drives hormones and muscles, it’s easy to see how it all connects.

It’s about looking beyond the banner headlines and understanding the systems behind the illness or disorder. Hall gives a potentially controversial example that shows how chiropractic research and basic science might create links while we wait for larger trials. It’s the issue of ADHD – Attention Deficit Hyperactive Disorder.

“If you look at ADHD, the imaging says that the problem is in the right prefrontal cortex. Heidi Haavik’s work shows us that chiropractic has an effect on the prefrontal cortex. The research says that adjustment affects the prefrontal cortex. It makes sense that if we have a way of affecting the prefrontal cortex that we might have a way of affecting ADHD. But we have to possibly look at it as a function deficiency before it becomes it a condition. If we go back into paediatric research, low axial tone is a precipitating factor for ADHD. The chiropractor who can harness the function of the vestibular system to improve the tone of the spine can increase the afferent feedback to the prefrontal cortex to develop the cortex.”

We can’t yet claim to ‘treat’ ADHD. But functionally, it’s not hard to see how chiropractic care may play a role in increasing the function of a patient with ADHD.

Functional neurology isn’t a field that is owned by chiropractic. It is something that can be seen in other health disciplines. “In 2013, the Journal of Neurosurgery dedicated almost the entire year to the cervical lordosis,” says Dr Hall. It was clearly an area deemed worthy of that sort of attention for the journal.

Chiropractic is a field perhaps ideally positioned to help patients restore the cervical curve without surgery. We may not think of it as functional neurology, but functionally, the neurological impacts could be profound.

It might be tempting to ditch the study of embryology, physiology or basic science and let the textbooks gather dust once you’ve left university. But according to Dr Hall, there’s a lot to be gained by staying on the cutting edge.

When we know what to look for, we can more easily make the links that show us where these functional-neurological gems hide in research and in practice. But more to the point, we can serve our patients better. And in the end, isn’t that what its all about?

There’s a long way we need to go in terms of research, but until we get there, harnessing basic science and linking it with what we already know about chiropractic is a good place to start.


[1] Meyer, A and Leboeuf-Yde C (2018), “Unravelling functional neurology: a critical review of clinical research articles on the effect or benefit of the functional neurology approach,” Journal Chiropractic and Manual Therapies, retrieved 24 Oct 2018

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