Fatigue After Traumatic Brain Injury
How traumatic events lead to a multitude of causes for long term fatigue
“Everything costs more energy than before” is a phrase I encounter every day in clinical practice.
Fatigue, oversensitivity to sensory signals from the environment, and headaches seem to be one of the most persistent problems you have to cope with when dealing with the aftermath of a concussion. It is also for any health care professional one of those big enigma’s to solve when dealing with the results of traumatic brain injury (TBI). To be quite honest, I have personally been struggling with solving these issues for the last 30 years.
I even dare to say that finding the key to quickly resolving fatigue, energy issues, oversensitivity for light and/or sound and headaches is similar to finding the holy grail for solving post-concussion problems.
The one thing I learned over the years is that there is no such thing as one cure for all when it comes to these issues. If anyone ever claims that they can help you to get rid of them because they have helped so many before, be aware that perhaps you should reserve a healthy amount of skepticism as to the outcome.
To explain and make you aware of the complexity of underlying factors I have taken on the task to explain in a series of blogs and video’s why fatigue, oversensitivity to sensory input, and headaches are in many cases so difficult to solve in lasting problems after traumatic head injury.
By showing you all the players involved, it will become easier for you to not only understand what is going on but will also help you to find better solutions for the ongoing problems you are experiencing.
Cutting edge science gives plenty of clues what to do and I am going to share this with you in the blog series.
The very fact that no one has come up yet with a simple solution says enough. In the first video and blog, I will, as the title suggests, go into the probable causes for fatigue after TBI, I will describe the factors and mechanisms involved (in not too much detail), so you get an overview of what might be going on, as well as start to understand the complexity of solving fatigue.
In subsequent blogs and videos, I will go into more depth into the different factors such as neurovascular uncoupling (which means that the circulatory demand of a certain brain area is not met with increased activity) brain inflammation (where the immune system in the brain keeps playing tricks leading to brain fog, inability to do things, oversensitivity). Later series of blogs and videos will go into the problems of headaches, oversensitivity, dizziness, cognitive problems, and their underlying mechanisms. Most important for you perhaps, is that the blogs relating to the individual causative factors will indeed contain solutions that will enable you to turn to solve them in the right direction.
Before we dig into the jungle of issues causing or contributing to fatigue after TBI, a word of warning. As you probably understand by now (most likely your personal experience), there is often not an easy solution for fatigue after TBI.
What will follow now is a cumulation of the latest insights through scientific research, personal clinical experience, and observations as well as personal opinions of the last 30 years.
When taking a helicopter view the following players appear to play an important role in the causation of fatigue:
· 1.Local and global circulation issues
· 2.Brain inflammation
· 3.Energy crisis at a cellular level
· 4.The survival (limbic)mode of the brain is overactive
· 6.Blood sugar issues
· 7.Gut Brain interaction
· 8.Blood brain barrier
· 9.Hormonal depletion
· 10.Brain network disparity
· 11.The interplay between head, neck, and eye function
· 12.Neck (cervical disfunction)
· 13.Central vestibular issues
· 14.Real damage in the white matter tracts
· 15.A(n)(pre) existing pro-inflammatory state
· 16.Psychological factors
· 17.Genetics (yes, even genetics)
As you can see there are plenty of them, and in reality, when dealing with ongoing fatigue there are several of these factors underlying the ongoing problems.
So which ones do we know have the most impact? If relating to just the scientific literature, mitochondrial disfunction (energy crisis at the cellular level), local circulatory problems (neurovascular uncoupling), and ongoing neuro(brain)inflammation top the charts. The others though may play an equally important role in individual cases (so whenever trying to solve fatigue after TBI we should never take this out of the equation). Equally important in my opinion is that we should not forget that issues like disfunction of balance, sensory systems (like tinnitus), eye functionality, cervical disfunction, and mismatch in the interplay between the vestibular system, neck input, and steering mechanisms of the eyes to name a few can also cause a depletion of energy levels, although probably to a lesser extend.
Of all of these Mitochondrial problems, or better said dysregulation of the energy factories in the cells of your brain, is the one you should become the most familiar with. Why? Because if we believe the researchers it underlies most of the other problems. If the energy production at the cellular level stagnates everything comes to a standstill, which makes sense does it not?
Brain inflammation, neurovascular uncoupling, and energy crisis
To not overcomplicate things, we can safely assume that the big three in fatigue after TBI are: brain inflammation, neurovascular uncoupling, and energy crisis, in no particular order. Further, I hypothesize that these are probably closely followed by limbic overdrive (read the flight system -sympathetic nervous system - is overactivated), brain network dysfunction, system dysregulation, (being gut-brain, central vestibular most likely), and other physical dysfunctions.
Note again that I put an order on the importance to keep things simple. Science may prove this particular order to not be completely correct (at present no studies are ranking this importance).
Because this article is meant to give you an overview of the factors and mechanisms that play a role in the causation of fatigue I will briefly describe the possible role (as far as we know from research and clinical observations) of all of the aforementioned factors, starting with elaborating somewhat more on the most important factors and mechanisms.
What can do to improve them.
Then in later writings, I will elaborate on the role of each of the players and go into more detail about the underlying mechanisms and you can do to improve them.
Introduction to the most important factors:
· Brain inflammation: Whenever there is a brain trauma the immune system of the brain rushes in to consolidate the situation, save what can be saved, shield off the impacted area and clear away debris. There is one big issue with the immune system of the brain (the microglial system) It is not as sophisticated as the immune system of the rest of the body. Once turned on it is very hard to shut off. Many experiencing ongoing issues like brain fog, mental fatigue after brain injury are dealing with an overactive immune system in the brain causing an ongoing low-grade immune response in the brain. (note that luckily under the right circumstances that we will go into more detail in other publications it can become quit again) Brain inflammation causes fatigue and can even hinder activity in the rest of the body.
· Neurovascular uncoupling: now these are some big words for simply saying that somehow the shunting of blood to areas that you want to activate in your brain does not efficiently take place any more. The result is that partaking in for example cognitive activities will be hindered by the fact that not enough oxygen and nutrition is shunted to the to be activated area(s). This explains also many of the cognitive deficits we see after brain injury).
· Energy crisis at the cellular level. One of your body's most important warning systems is the mitochondrial system. Mitochondria are tiny cell inclusions that produce energy whenever needed. Without mitochondria, you simply cannot exist. So what is the deal here? Mitochondria either are producing energy, or they are in cell defense mode. In the face of brain trauma mitochondria, just like when there is inflammation somewhere else in the body, oxygen depletion, toxicity, etc. will go in defense mode, protection, repair, basic survival is all they can think. The result is no energy production. Now researchers have shown, just like in the case of neuroinflammation that this can be an ongoing state. Hence a serious energy crisis is there, further complicated by ineffective ways to produce energy that will lead to a build-up of waste products and further compromise energy production. This as you understand will cause some degree (if not most of the fatigue). In the blog and video about this energy crisis, we will dig deeper into this phenomenon and the many things you can do to remediate mitochondrial shutdown (see also the energy masterclass).
· Sympathetic (limbic) overactivation: Your brain goes into survival mode after head injury. It wants to survive, and in many cases, these reactions are strong (and probably also based on previous experiences, the level of stress, physical, mental, and chemical fatigue already present at the time of the impact) Circulation and activity is shunted to the more primitive parts of the brain the deeper limbic (emotional) systems and hindbrain. The parts on the outside of the cortex where higher brain functions take place, such as active thinking, speaking fine motoric control become compromised and already present neurovascular uncoupling is further enhanced. The result, a further enhancement of general fatigue.
· The networks become dysfunctional. The last item I want to cover and highlight in this section is one of great importance as well. The different big networks of the brain appear to become dysfunctional and more inefficient. Meaning that a task takes a lot more effort than previously. Instead of one network being more active we see that inefficient activation of multiple networks at the same time takes place when higher cortical tasks like speaking are performed. Default networks that are active in the background suddenly light up when attention networks are concentrating on a specific task. Normally so-called default networks are hardly activated when specific tasks need to be performed. This is a sign of efficiency in the brain that can become dysregulated by a brain injury.
Although the previous items seem to contribute the most to the fatigue experienced after TBI, as mentioned before, other issues can play an equally important role in the sideline.
In the following section, I will describe some of the other factors that can have a big impact on energy levels and the experience of fatigue after TBI.
· Brain gut axis issues: Now although at first glance may be far sought, for some a disturbed gut-brain axis relation may be one of the most important factors in the fatigue story. Let me explain. Researchers have shown that brain injury if severe enough to cause a concussion will in most cases have an almost direct effect on the gut. The brain-gut axis through the vagus nerve becomes negatively influenced and the regulatory role of the brain on the gut becomes impaired. Fewer secretions, motility moderation of the immune and fight-flight system will result. Messengers and messages from the brain to the gut cause the gut lining to become leaky which has a huge impact on the body's immune system. It becomes overactive, also against food particles that you could previously handle for example. The disrupted interaction of the brain to the gut, in turn, leads to a more pro-inflammatory state of the body which eventually spreads to the blood-brain barrier and further enhances neuroinflammation and the fight-flight state the brain is in. Hence a seemingly perpetual dysregulated state. A dysregulated gastrointestinal system will unbalance good vs, bad gut bacteria which will negatively impact the brain since the end products of good gut bacteria have a very important stabilizing role on the brain and vice versa. When the gut microbiome (the forest in your gut) becomes disrupted your brain becomes that too. In other words, this, for some becomes a very important issue in the quest for answers when fatigue is in play. Energy levels in your brain and body are after all determined for a big part in what goes through and happens in the gut.
· Hormone levels can equally become dysregulated, by anatomical disruption of the pituitary gland or hormone axis (hypothalamus which is lodged just above the brain stem and under the deep brain nuclei). The brain is the most important driver of this axis. Hormones play a very important role in your body and brain's energy levels. Thyroid, estrogen, and testosterone levels all play a vital role and can become compromised.
· Blood sugar levels are another important factor to look at. What drives the brain is oxygen, fuel in the form of glucose (preferably slowly released) and activation. We know from research that glucose levels after a head injury initially go way up (probably for the repair and protection of the affected areas) and after that crash, Glucose metabolism into energy becomes skewed and a lot of unwanted byproducts in the energy production which further enhance the pro-inflammatory state are the result. This state can also outlast the first week of the event and may contribute to the fatigue that is experienced. In any case, pre-existing or later blood sugar issues (because of the impaired brain organ regulation, immune issues
dysregulating pancreatic tissue) can have a huge impact on brain function and therefore be a determining factor in fatigue formation.
· Sleep issues are a really big player as well. Quality of sleep, (among others because of all the other processes that were mentioned before) is reduced in a significant portion of people that are dealing with a traumatic head injury. When you consider that sleep is probably the most important factor for recovery after brain injury then it is easy to see how this impacts brain function and further deepens the fatigue cycle (although I do not explain much about sleep problems its impact and what to do with it, I will do so in an article entirely devoted to the impact of sleep and how to use this to turn fatigue issue into the right direction)
Locomotor and vestibular system and the brain
The last factor that I want to point out, and one that will be discussed in-depth in future blogs and videos is the one involving the interaction between the locomotor and vestibular system and the brain. What many do not realize is that for the brain to develop and function optimally, there is a need for constant input from the body to the brain. One is from the internal organs (as discussed in previous points -for example, the guts microbiome influence on the brain- )the other is important from especially the postural system, to be more specific the deep spinal muscles. They provide the brain with a constant source of input under the influence of gravity. Only when lying down does this input go down to a level where the brain is not activated as much. Researchers have shown that this input is for a big part responsible for the binding of bodily movement and brain movement(read cognition). Information from your deep postural muscles makes it possible to activate different brain parts at the same time and provides a basic level of arousal needed to efficiently engage your brain in tasks you want it to perform. Why is this so important in this fatigue introduction? For one big reason: The neck, where about 90 plus percent of all movement information comes from, often becomes affected by brain trauma (think of an impact to the head) thus affecting the efficiency and feedback to the brain. This factor is often overlooked and can have as many consequences as a mild to moderate concussion.
A very last thing that I will say about the factors and mechanisms that will be covered in my next writings is the impact that the interplay of the vestibular system, the neck information and eye functionality, and the brain. All important for spatial awareness, body orientation towards others and oneself as well as how information is processed and stored. When considering that this is one of the most vulnerable systems when a head injury occurs it is easy to see that this can for some become a major factor in the causation of fatigue.
I know this was maybe a lot to digest, in any case, it was not meant to disturb you or worry you. What I tried to do is to point out the complexity as well as some of the main players in fatigue after TBI. By no means complete, but the most important factors and mechanisms have been described at least somewhat. In the next blogs and videos, I will lay out how all these factors play a role, in more depth and also show what can be done to ease the influence of all of these factors on fatigue after brain injury.
When dealing with fatigue after traumatic brain injury, there are many factors to take into consideration. I hope to have made you aware of the fact that because some things, like working, talking, sleeping thinking and headaches are causing you (for example because you constantly have to compensate for the loss of efficiency) to have to put in more energy than before is only part of the fatigue equation. Other factors as you have read, are often even more important. This will probably also make it more clear why you might not have found all the answers yet.
The good news is, now you are more aware of the underlying problems, you can start taking action to find better solutions to remediate your fatigue as you will learn and see in subsequent blogs.
Diplomatic status with the American Chiropractic Neurology Board (ACNB) since 1997
Official member of the International Association for Functional Neurology (IAFNR)
DC, BSc, DACNB, FACFN, spFEAC, CPN, CPE Specialized Chiropractor
Consultant Applied Clinical Neuroscience