Traumatic brain injuries

I’m not sure if it is only me or if there really has been an increase in the amount of information regarding concussions and concussion management. It could be because of the summer as there’s usually an increase in injuries in the summer months since people are being active more.

While I am not an expert on the direct treatment of concussions from a physical medicine perspective (a chiropractor or physiotherapist trained in concussion management can help you with that), traumatic brain injuries (TBI) generate inflammation.  This is because the connective tissue layer within the meninges is torn leading to an increase in reactive oxygen species which trigger inflammation within the brain, cell death and consequently a “leaky” blood-brain barrier (1).  The “leaky” blood-brain barrier can then contribute to brain swelling due to drawing electrolytes and more inflammation.  While some degree of inflammation is needed to generate tissue repair, increased inflammation can lead to age-related neurodegeneration over time (1).  This pro-inflammatory state associated with concussions and TBIs can also activate the stress chemistry system – this is the hypothalamus-pituitary-adrenal (HPA) axis (2) and contribute to autonomic nervous system dysregulation (1,2) leading to sleep issues, digestive difficulties, in females it can affect the menstrual cycle, and in both males and females, it can lead to hormonal imbalances.

This can be why many people may feel as if their digestion or their sleep issues or generally they have been feeling unwell (low energy, anxiety, or feeling depressed) ever since they had that concussion or head injury. Depending on the degree of these other health issues, it can make it harder to obtain sustained improvements from your concussion recovery treatments.  Supporting the HPA axis, improving sleep, and reducing inflammation are other important areas to address, which can help you enhance healing and recovery.

Stress Chemistry

The brain inflammation in a TBI activates the HPA axis to increase cortisol (a stress hormone that also helps to suppress inflammation).  This leads to a decrease in the TH1 subclass of T lymphocyte cells (TH1 helps us to fight infections) and NK cells.  Less TH1 can mean that TH2 T lymphocyte cells dominate which can manifest as an increase in allergy-like symptoms/asthma/eczema.  A decrease in TH1 can also contribute to dysbiosis (microbial imbalance within the intestines).  This dysbiosis can begin to manifest within hours of a TBI due to the inflammation (2).  Dysbiosis further creates gut inflammation, “leaky gut” and other health issues associated with gut inflammation and “leaky gut”-like autoimmune conditions.  Gut inflammation also disrupts the gut-brain axis.

The increase in cortisol can also affect your sleep as under normal circumstances, cortisol is meant to be the highest in the morning upon waking and lowest at night so melatonin can increase at night helping us sleep.  If cortisol is increased at night and/or increases in the middle of the night, this can make it difficult to fall asleep and stay asleep.  Functional adrenal testing can help determine your cortisol rhythm if you think this can be a factor for your sleep issues.  Any STRESS, in general, can contribute to cortisol dysregulation!

There are many ways from dietary and lifestyle strategies to supplements like ginseng or ashwagandha that can help balance the HPA axis and improve sleep because sleep is one of the most fundamental needs to reduce inflammation, weight gain, and promote healing.  The latter is due to sleep inducing the production of brain-derived neurotrophic factor which helps to repair tissue (1).  It is best to consult a naturopathic doctor to determine the best adrenal support for you as they are different herbs and nutritional supplements depending on where your cortisol levels are on the adrenal spectrum.

Autonomic Imbalance

Your autonomic nervous system consists of a parasympathetic branch controlled by the vagus nerve and a sympathetic branch which involves norepinephrine/epinephrine (adrenaline). The sympathetic branch is activated in times of stress vs the parasympathetic nervous system which is known as the “rest and digest” nervous system. This branch gets activated during relaxation states like meditation. 

Norepinephrine can trigger anxiety, insomnia, and high blood pressure. During a TBI, there is an increase in norepinephrine (adrenaline) leading to a state of sympathetic dominance which can decrease vagal nerve function.  Decreased vagal nerve activity means the motility within the gut is altered. Stomach acid, digestive enzymes and bile flow are also decreased leading to symptoms such as heartburn/bloating/gas/diarrhea/constipation and abdominal pain.  It can also predispose one to small intestinal bacterial overgrowth (fondly known as SIBO). 

This is a reason why IBS can be very common among post-concussion patients.  Functional digestive testing can give a clearer picture of what is going on. Addressing digestive problems once they manifest and healing the gut can help with healing as it can reduce inflammation in the body.

As an aside, meditation has been shown to help with increasing vagal nerve activity and increasing parasympathetic nervous system activity.

If you have been suffering from post-concussion symptoms for years and find that physical or manual therapies provide relief in the short-term, only to have symptoms return once you stop the treatments, it may be worth considering looking at what is happening internally within your body as each body system is interconnected.  Regulating cortisol (and other hormone levels), your autonomic nervous system, and addressing any digestive symptoms that are now present will work to minimize inflammation and enhance the positive outcomes from your other therapies. 


  1. Dr. MacLellan N. ND, RD, CISSN and Nelson DH, ND (cand.)  Foundational approaches to concussion management.  CAND Vital Link.  2019;26(1):25-27.
  2. Zhu CS, Grandhi R, Patterson TT, Nicholson SE.  A review of traumatic brain injury and the gut microbiome: insights into novel mechanisms of secondary brain injury and promising targets for neuroprotection. Brain Sci. 2018 June;8(6):113.
  3. Spear N, MS, CNS.  Concussions and the Gut-Brain Axis. 25 September 2018.  Retrieved from on August 3rd, 2019.

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