You’ve had concussion, you start rehab, maybe you are beginning to feel less symptomatic, but how do you know if you're fully recovered? Will you ever be fully recovered? Are you being prescribed the appropriate treatment interventions for your unique brain injury? These are all important questions not only to you as the patient but hopefully to the provider that is managing your care.
First lets lay out a general guideline of what happens during a concussion. During a concussive event your brain is exposed to a series of different vectors that can ultimately lead to torsion and sheering and even blunt force trauma to take place. When this occurs there are areas that are more naturally vulnerable to experience damage. Imagine a wet towel getting rung out, when this takes place the center of that towel will undergo the most amount of torsion. The same things happens to your brainstem and it ends up placing a lot of stress on a particular area called the vestibular nuclei due to it is location in the center of the brainstem.
This areas in the brainstem takes in information from the inner ear (vestibular system), your neck, and your visual system. Think of your eyes, neck, and inner ear as a triad that supplies information to the brain about where you are located in space. When one of these systems gets damaged and can no longer transmit the appropriate signal, the other two have to pick up the slack and work overtime in order to supply the brain with all the information it needs. This is extremely important because humans are designed to move and in order to move you first have to know where you are so that you can coordinate the appropriate muscles required to do the intended task.
Now lets define rehabilitation, compensation, and habituation. Rehabilitation is defined as “the action of restoring something that has been damaged to its former condition.” An example of this would be after a mild traumatic brain injury and after sitting through an examination the physician comes to the conclusion that there was dysfunction of the right vestibular system and treatment is then performed to restore that area to its former condition. Compensation is defined as “something that constitutes an equivalent”. For example, if we use the same vestibular injury as before this individual could use his visual system to make up for the lack of vestibular input being supplied to the brain. (1) Now while this may make you feel less symptomatic at times, it wouldn’t be considered rehabbing the area of injury because you are meerly using a healthy area in place of the damamged area. Lastly we have habitation, which is defined as “the diminishing of a physiological or emotional response to a frequently repeated stimulus.” Habitutation can be thought of as if a patient presents with a sense of dizziness when there is excessive visual motion in front of him and the treatment that is performed is just exposing them to that provocative stimulus until it no longer makes them dizzy.
For most patients, after a mild head injury symptoms will disappeared within a few weeks to a month, and the patients return to their normal lifestyle and are happy with their recovery. (2) If we continue with the example of a patient with a vestibular injury the term used to describe that general recovery is vestibular compensation, and superficially it seems that there is a full recovery and vestibular function has returned back to normal. Indeed, in a few patients this is exactly what happens. Some patients will have complete restoration of function however, in most patients there is little to no restoration of function, and they will utilize other sensory systems to compensate for the faulty vestibular information. (3) Here is where the trouble begins to start; while this new compensation may currently benefit you in the form of less or even no symptoms, the recovery is incomplete. You end up just kicking the can down the road because at some point that compensation will fail due to another bump on the head, normal degeneration as we age, nutritional deficiency, environmental factors, etc,
We see it all the time where a patient will present with dizziness and no recent trauma or inciting event that they know of caused this to occur. However, once we start asking questions and find out they had sustained a concussion a number of years prior and never underwent any form of treatment it starts to make more sense. Think about it like a broken mirror, you can take all the pieces of that broken mirror and tape them together and you will still be able to see a resemblance of yourself in that mirror. However, it would be much better if you put a new piece of glass in that mirror. Now unlike a mirror, we don’t have the luxury, at this present moment to buy new pieces of our brain and start fresh. With that being said full recovery isn't always an option for every injury and so there are times when compensation or habituation make sense to help alleviate your current symptoms. Once you’ve seen one brain injury, you’ve seen one brain injury. Every person is unique and every experience you have makes how you will naturally compensate after a brain injury different from someone else. (4) During more extensive injuries there are areas of the brain that can become permanently impaired and then it comes down to job of the physician to try and make appropriate compensations for the patient to be able to live with because rehabbing that system may not be an option.
I hope by reading this article you were able to recognize the complexity around concussion and being able to find a provider that will not only get you feeling better but also set you up with the most advantageous treatment strategies whether that be actually rehabilitating the system, compensating it with another system, or just habituating the provocative stimulus. All methods have their place but not all methods are appropriate for you. If you are interested in learning more about our approach to treatment and how we might be able to help you, click the contact us button at the top of the page and schedule a complimentary phone consult with the doctor.
1. Dutia MB. Mechanisms of vestibular compensation: recent advances. Curr Opin Otolaryngol Head Neck Surg. 2010 Oct;18(5):420-4. doi: 10.1097/MOO.0b013e32833de71f. PMID: 20693901.
2. Curthoys IS. Vestibular compensation and substitution. Curr Opin Neurol. 2000 Feb;13(1):27-30. doi: 10.1097/00019052-200002000-00006. PMID: 10719646.
3. Macdougall HG, Curthoys IS. Plasticity during Vestibular Compensation: The Role of Saccades. Front Neurol. 2012 Feb 28;3:21. doi: 10.3389/fneur.2012.00021. PMID: 22403569; PMCID: PMC3289127.
4. Balaban CD, Hoffer ME, Gottshall KR. Top-down approach to vestibular compensation: translational lessons from vestibular rehabilitation. Brain Res. 2012 Oct 30;1482:101-11. doi: 10.1016/j.brainres.2012.08.040. Epub 2012 Sep 6. PMID: 22981400; PMCID: PMC3490401.