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For Student-Athletes With
A Sport-Related Concussion

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School and Home Rehabilitation Plan Will Be Worked Out With Classroom Teachers

Specific Strategies Designed to Reduce The Risk of Repeat Concussions

Contact Robert Kirwan For More Information About These Services
(705) 969-7215 or 
(705) 586-PURE (7873)
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Concussion Management
Program Development
For School Boards
& Minor Sports


Concussion Management Consultation Services
For School Boards


Concussion Management Consultation Services
For Minor Sports


CMP Program Development Guide
Click for a free PDF copy of the Book

Program Development Guide 
What is a Concussion?
Signs, Symptoms & Behaviours
A Partner Approach
Understanding The Brain
Essential Elements
Baseline Assessment
Concussions & The Law

Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012
British Journal of Sport Medicine with Links to Related Reference Articles
PDF Download Copy
Review of Statement by CMP
Child SCAT 3
SCAT3 - Pocket Version
Sport Concussion Library
ImPACT Test Web Site
Other Links and Articles

(An excerpt from Chapter Twelve of the CMP Program Development Guide which is provided to all people who participate in one of the Training & Program Development Workshops Sponsored by CMP Concussion Management Partners Inc.)


Concussion is a word that is used to describe a brain injury which has been caused by violent and sudden shaking of the brain inside the skull. This shaking usually results in the brain striking against the rough inside surface of the skull with significant impact and often includes twisting caused by rotational forces. This creates a brief deformity in the shape of the brain which produces biomechanical changes in the brain that disrupt the brain’s synapses causing a temporary loss or impairment of brain function which produces a variety of physical, cognitive and emotional symptoms. This impairment can be relatively mild or it can leave the person in a state of unconsciousness. It should be pointed out that the majority of concussions do not involve a loss of consciousness.

It is generally accepted that a concussion results in functional deficiencies or symptoms may in fact be the result of “structural” damage to the axons and synaptic connections which transmit signals between the neurons. Therefore, while the symptoms may be functional they may be caused by “structural” damage that is too microscopic to be detected by most normal scanning technology, therefore the only way of knowing that most concussions have occurred is by identifying signs, symptoms and behaviours that are consistent with concussion. That being said, one of the difficulties with brain injury is that it is not always easy to identify the signs, symptoms and behaviours. This is one of the main reasons why we are going to spend so much time examining the signs, symptoms and behaviours consistent with concussion.

Nevertheless, it must be pointed out that a concussion may be accompanied by structural damages such as a fractured skull, increased intracranial pressure caused by the swelling of the brain, ruptured blood vessels inside the brain and damaged muscle tissues to the neck area. Some of these structural damages may be life-threatening and need to be either ruled out or attended to immediately. They are usually easily identified by a medical practitioner who has access to imaging machines or who is familiar with such injuries.

A concussion is also often referred to as a mild traumatic brain injury (MTBI), a traumatic brain injury (TBI), or an acquired brain injury (ABI), so when you see those terms used they all mean pretty much the same. However, we wish to point out that the use of the words mild, moderate or severe are beginning to be eliminated from the description of most brain injuries since there is really nothing mild about a concussion and the severity of the injury is extremely hard to determine. Hence, it is said that all concussions are serious since they are all brain injuries.


Before we get into the specific signs, symptoms and behaviours consistent with concussion, I think it is important for us to have a clear understanding and to totally accept that a concussion is an “injury” to the brain. Many people would like to drop the term “concussion” and simply call it a “brain injury”. Then everyone might take the injury more seriously.

In fact, a concussion is one of the injuries that falls under the general scope of a “head injury”. For example, when we say a person has a head injury, he/she may have a laceration to the face; an injured eye; a broken nose; a fractured jaw bone; damaged teeth; a bleeding nose; a fractured skull; a bump on the skull; muscle damage in the neck region; or a brain injury. So if you say that you have a head injury, you really haven’t told me anything. You have to be more specific by identifying exactly which part of your head was injured and describe the signs or symptoms.

This is no different from a leg injury, a shoulder injury or a back injury. You must point out which part of the leg is injured and then detail the injury in order for us to understand the extent of the damage. If you just say you have a leg injury, I may pass it off by default as a minor pain or discomfort. If you may say you have injured your knee, then that makes it more serious and I may suspect that you will have trouble moving around. Nevertheless, it could be a torn cartilage, a bruise, a strain, etc. so I may once again pass it off as a minor knee injury that doesn’t have much of an affect on your movement. The natural tendency is for us to assume that an injury is minor unless you tell me otherwise. I automatically assume that if you had a broken leg, you would have said you had a broken leg and you would not have just said you had a leg injury. If you say you hurt your hamstring, I will assume that you have a slight pain or stretching of the muscles. I will assume that if you had a torn hamstring you would have told me that since it then establishes the level of seriousness.

The problem with brain injuries is that they are unlike any other kind of injury you can experience anywhere else on your body. A brain injury is indeed a type of head injury. However, a brain injury may have an impact on other areas of your body that were not injured in the first place. And to make matters worse, a brain injury may have been caused by a force that does not have to have been applied to the head. All that is needed to cause a brain injury is for the brain to have been sufficiently shaken or twisted to the point where it struck the inside surface of the skull or was somehow temporarily deformed, causing stretching and shearing of axons and synaptic connections which then disrupt the chemical balance and communication system that is so critical to the functioning of the brain, our central nervous system.

The consequences of damage to the brain may be far reaching and could affect coordination, balance, vision, reaction time, etc. that render us somewhat disabled in areas that were not injured in the first place.

So when a person says they have a concussion, we tend to assume that it is a minor injury that will resolve in a few days because that is what usually happens. We once again assume that it is minor. If you say you were unconscious, then it raises our image of the injury to a higher level. The fact is that being rendered unconscious is no indication of the severity of the concussion. Some people who lose consciousness recover from their injury faster than those who do not. Such is the nature of traumatic brain injury.

But despite everything else we still assume the “least damage” position and will expect that everything will be fine in a week or so. To put it in context, if someone approaches you and simply says they have a leg injury, you may ask them if they would like to go on a hike with you in a few days. However, if that person is on crutches and says they have a broken leg, you will likely not invite the person to go on a hike. So if someone tells you they have a concussion, but otherwise they look healthy, it is hard to understand what limitations that person is under. It is even hard for the person with the concussion to understand why he/she must avoid activity if he/she feels well enough.

The other problem with an injury to the brain is that it turns the body into a “minefield”. It is very difficult to know exactly how a brain injury is going to present itself. The symptoms are unpredictable and every concussion is different. They are like snowflakes – no two are alike!

Once you go beyond the usual headache, dizziness, and fogginess, the damages to the neurons, axons and synapses, coupled with the chemical imbalance and the interruption of normal communication between the neurons, a brain injury may prevent you from performing functions that you once took for granted. And you won’t be aware of these problems until you try to perform those functions.

For example, until you try to tie your shoelaces, you may not be aware that you cannot remember what to do. You may not be aware that the brain injury has changed your ability to recall material for exams until you write an exam. You may not be aware that your brain injury has affected your ability to catch a baseball until someone throws a baseball at you and routine catch becomes a real challenge.

The other problem with a brain injury is that some of the symptoms take a long time to resolve. While your brain is in recovery or rehabilitation mode, you are more vulnerable to further damage, not necessarily to the area of the brain that was damaged in the first place, but to other parts of the brain that escaped the first injury. Imagine if you twisted your left ankle and decided to rest that ankle until it felt better. Then imagine that once it felt a bit better you tried walking on it before it healed fully. You find that you can walk very gingerly but you know that the ankle has not healed yet. Now imagine that while you were testing your ankle your wrist suddenly broke for no apparent reason. There is no connection between your wrist and your ankle, but you now have a strained ankle and a broken wrist, so you are even more disabled than you were in the first place. You realize that if you would have waited a bit longer for your ankle to heal fully your wrist wouldn’t have broken.

That is how it is with a second brain injury that occurs before the first brain injury has healed. In the ankle example, you would have understood if the ankle became more painful and your injury was confined to the original location. That means that your functional disabilities would continue and your actions would be limited due to the ankle injury. But if your wrist breaks because you tried to test your ankle, then you have a whole other set of symptoms that are going to cause much more widespread dysfunction. Now you’ve got an injured ankle and a broken wrist. This time you are definitely going to take longer to heal and you are going to be a little more hesitant to try to return to normal too quickly for fear of causing some other damage to another unknown part of your body.

Keeping with the analogy of the injured ankle and the wrist, imagine if you were resting your ankle and while you put pressure on your wrist by lifting a heavy object, your ankle started to hurt again. That is what happens with a concussion. The only way to make sure that your ankle doesn’t suffer any further damage is for you to do nothing – to go through a period of time when you are at complete physical rest. So when you have a concussion, the only way to be sure you won’t do any further damage to the injured parts of your brain is for you to do nothing – physically or mentally.

Imagine a major fire breaking out in a part of the city which requires virtually all of the firefighters to be called out to battle the blaze. While they are fighting the first fire, it puts the rest of the city at greater risk. If another fire breaks out on the other side of the city while the fire crews are fighting the first fire, not only will it take longer to get to the other fire, but the attention that is available to give to the first fire will be reduced and the damages will be greater to both areas.

Now imagine what happens in the brain when a student-athlete suffers his/her first brain injury and no one spots the signs, symptoms or behaviours consistent with concussion. The student-athlete may inadvertently go back into the game and receive a second brain injury which has much more serious consequences because of the vulnerability of the brain from the first injury.

That is why it is so important to identify that first injury.

Keep in mind that your brain is the central nervous system of your entire body. When you disrupt the communication system you are causing problems that are widespread in scope and it is very difficult to know exactly what symptoms that disruption is going to cause. And if a second disruption occurs while the brain is repairing the first damaged areas, then all of the other connections are at risk.

For example, you may buy an airplane ticket to fly from Toronto to Japan . Imagine how frustrated you would be if it is sunny in Toronto and Japan , but there is a storm in Vancouver . Since you were supposed to stop in Vancouver on your way to Japan , the storm in Vancouver will delay your flight from Toronto and you will not be able to get to Japan . You will have to wait until the storm clears up in Vancouver before flying out. But then, once the storm clears up in Vancouver , it may still be a while before you can take off from Toronto because there may be a back up of flights that have to get to Vancouver before you.

Your only other choice is to see if there is another way to get to Japan, so you may try to get a flight to San Francisco and then go to Japan from there. It is possible, but it may take a bit longer for the flight and you may need to wait to get a ticket to San Francisco to make the connection to Japan . While you are doing this, Vancouver may open up and now you don’t know what to do because you already have your new ticket to San Francisco . You may decide that you will use the San Francisco route to Japan from now on, but that means that future flights may be longer and more costly. Eventually, you may try to go back to your normal route through Vancouver . However, if enough people thought the way you did about establishing a new connection through San Francisco , the airlines may have decided to cancel the route from Toronto to Japan and you will have no other choice but to follow the new path forever. That is what happens in the brain to the connections between neurons as a result of a brain injury.


We are obviously focusing our attention on sport-related concussions, but we should remember that a concussion can be caused by any kind of activity that causes the head to move rapidly and change speed or direction. This sudden change in speed and/or direction of the head is what causes the brain to shift inside the skull. The brain is a soft, jelly-like substance that is suspended in cerebrospinal fluid, so if you move the “container” rapidly enough, the brain will push through the protective cushion provided by the fluid and will smash against the surface of the skull, crushing and deforming its normal shape. It will momentarily bounce and twist until the movement of the head ceases. All of this can happen in a split second.

It is important to note that this rapid movement of the head does not necessarily have to be the result of a blow to the head. In fact, the actual contact can be made anywhere on the body. If that contact with the body causes the head to change direction rapidly, then damage to the brain inside the skull may result. Admittedly, the blows to the head are the ones that cause the most damage, but any blow to the body should be cause for concern when it comes to identifying the signs, symptoms and behaviours consistent with concussion.

No matter what definition you use, the fact remains that a concussion changes the way the brain functions. What is not known at this time is how long or how permanent the damage will remain.

Many people refer to a concussion as a "mild Traumatic Brain Injury" or a temporary TBI. You will often see the definition include reference to the "rapid onset of short-lived impairment of neurological function that resolves spontaneously". However, there is great debate going on now as research points that the impairment of neurological function may not repair as rapidly as once thought and the resolution may not be as spontaneous as we had hoped.

This temporary impairment may be true for the most obvious symptoms such as headache and dizziness, but the long-term impact of a concussion may result in impairment of emotional and psychological functions as a result of the changes that occur in the brain.

In fact, there are studies that have found middle aged adults who suffered concussions while in college exhibiting premature brain aging and deficiencies in concentration, balance and motor control many years after suffering their concussions. It is most likely that most people who are suffering from these kinds of functional deficits may simply attribute them to normal aging and getting older, not even relating any symptom or deficit to their history of concussions. And yet, there may be things they could have done during rehabilitation that might have reduced or eliminated these functional deficits, thus impacting on their quality of life many years after the injury. Our goal in developing the most effective student-athlete concussion management program possible is to reduce the long-term consequences of sport-related concussions.


Evidence is being produced by researchers which proves clearly that a "concussion is a process". It is not an event. And this process does not simply involve "healing and recovery". Many symptoms of concussion do not present themselves for hours, days, weeks or months. In fact some people admit to experiencing concussion-like symptoms for many years following an injury.

We will concede that there may well be a rapid onset of short-lived impairment of neurological function in some areas that resolve spontaneously, but what about the long-term impairment that does not resolve. What about personality changes? What about anxiety and mood disorders? What about interpersonal relationship skills? What about one's attitude towards life? These are all recognized as signs and symptoms of concussion but they are also unfortunately accepted by most people as part of growing up and normal development. They may not be that normal after all.

Admittedly, we all change our personality slightly from time to time. We all have periodic bouts of anxiety and we are all moody from time to time. We all have some difficulties with relationships and our attitude towards life is often affected by our environment and the people around us. But for young people who suffer a concussion, are these changes part of their natural evolution, or are they consequences of their brain injury? And is there something we can do to reduce the risk of life-altering consequences?

Symptoms of a concussion may also not be evident until you are required to perform a specific task. For example, you may not even know that you are no longer able to recall math facts until you are asked to recite your times table. You may not realize that you get dizzy riding a bike until you have a chance to ride a bike. You may not know you have problems adjusting your vision when things are being thrown quickly in your direction from the side until this actually happens. These symptoms take time to present themselves and they will only be noticed if you have people around you who are looking for signs and symptoms of concussion. That is why we recommend using the "partner approach" to concussion management.


Axons get their shape from internal structures called microtubules which look like a string of sausages strung together. As the shape of the brain gets temporarily deformed from the twisting or rapid acceleration and/or deceleration, the axons may stretch or break. Normally, since your brain is constantly jiggling like a mold of jello, axons are often stretched gently with no damage to any of the internal skeletal structure that is found inside axons. This is what is often referred to as a “slow stretch”.

If the axons are stretched too quickly, they tend to stiffen up causing their internal skeletons to become destroyed and the axons will shear, causing a total interruption of signals. In most cases, concussions are mild traumatic brain injuries where the axons do not actually shear, but rather are stretched with enough force that they don’t quite rip apart but still sustain significant damage to their internal skeletal structure.

For example, if the axon is stretched hard enough, the microtubules that act like conveyor belts carrying nutrients from one end of the axon to the synaptic connections in its network may break at some point. When this “conveyor belt” is broken, the supplies that are being carried will continue to flow but they will basically “fall off” at the break and will collect inside the axon. This causes a “bulb” to form inside the axon. More importantly, it may prevent the part of the axon beyond the break from receiving the nourishment and supplies it needs to survive. Eventually, the part of the axon that is not receiving nourishment will wither away and die, thus disconnecting from the original axon. That means that signals that would normally have gone along that axon will no longer get through. This then causes the axons with the bulbs of protein to also shrivel up and die because they can no longer do what they are supposed to do and the neuron will die as well. All communication that was conducted that one neuron will then cease.

There are some injuries where the damage is beyond repair, but the communication is still continuing in a faulty manner. The signals are getting through but they are not clear. In this case the damaged connection may end up corrupting the entire system with static communication.

Dr. Douglas Smith of the University of Pennsylvania and a number of his colleagues have done extensive research on concussions and axonal damage. What they found is that if you stretch an axon gently the first time, it produces an increase in the number of tiny pores that line the outside skin of an axon. These pores allow sodium and calcium to come inside. If you stretch the axon gently a second time shortly after the first time, these tiny pores became enlarged and sodium and calcium came rushing in.

Other scientists had previously discovered that increased levels of calcium in an axon created an enzyme that actually ate away the internal structure of the axon. Therefore, the implication is that if a person suffers a seemingly minor blow to the head or body, there may not be any obvious symptoms of concussion present, but the stretched axons will be extremely vulnerable if there is another minor blow. That is why some people are surprised when they receive serious concussion-like symptoms from what seemed like a very small force. It’s because the axons were vulnerable at the time from the stretching caused by the first blow.


When the brain suffers from a force as a result to a blow to the head or some other part of the body, it experiences a "power surge" producing an extreme amount of chemical neurotransmitters, effectively "lighting" up the entire brain with electrical charges. This surge only lasts a minutely brief period of time and seems like a mini-seizure. The physical movement causes neurons and axons all over the brain to be pulled, twisted and stretched. Doctors call this a “diffuse axonal injury” because it causes injury to axons from a number of different places in the brain. It doesn’t affect a single area of the brain.

The neurons send out signals through the axons to allow sodium and calcium to enter through the tiny pores on the outer skin that have been enlarged by the twisting and stretching. At the same time potassium is allowed to rush out of the neurons through the axon openings. The problem with too much sodium is that it also brings in water which can cause swelling of the axons and thus dangerously increase intracranial pressure. Calcium produces an enzyme that eats away at the internal structure of the axons.

Once the initial power surge is over, the brain immediately attempts to restore the equilibrium and get things back to normal levels. The first thing the neurons do is send a signal to pump potassium back into the axon and pump sodium back out. The potassium counteracts the effects of sodium by neutralizing its electrical charge. This process requires a lot of energy which is usually produced inside the neuron by something called the mitochondria, which acts like an internal power plant for each cell.

The mitochondria require fuel in the form of glucose to produce energy. Glucose is carried to the neurons by the blood flow in the brain. The demand on the cell for energy causes a drain on the supply which causes the brain to lose power and operate on a slower speed. The brain then demands for an increase in blood flow in order to bring in more glucose to the mitochondria to repair the damaged areas. However, the message somehow is disrupted and the blood flow to the brain is actually slowed down. No matter how many signals the neurons send out for more fuel, there is no increase in blood flow and the cells are in danger of dying. Because of this the brain releases high quantities of potassium in order to try to calm things down even more.

It is common for student-athletes who have suffered a concussion to complain about feeling groggy or fatigued. This is because the brain is placing such a high demand on the energy being produced by the body. Consider that under normal circumstances, almost 25% of the energy being burned up in your body is being used by the brain. When the brain suffers a trauma, the demand goes up even higher, but the body refuses to provide that energy, actually reducing the flow to the brain. Hence, you feel very tired and disoriented.

Since each dendrite or axon may be part of a communication line that carries impulses to thousands of nerve cells as it winds its way around the brain, any damage to an axon or a synaptic connection can impact many areas of the brain in the network other than just the area where the original damage was caused. This domino affect can cause symptoms that may seem unusual based on the point of impact, but neurons in one part of the brain connect to neurons in other parts of the brain and may be part of a communication link with many other functions.

This is why we often see a variety of symptoms when a person suffers a concussion. The damage can affect your cognitive, physical, emotional and psychological functioning and it can play havoc with your sleep patterns and relationships.

Please go to the following link on Signs, Symptoms & Behaviours for more detailed explanations about how to identify a concussion. CLICK HERE >>>>


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DISCLAIMER: All content found on this web site is provided for information and education purposes only and is intended to provide viewers, participants, and other injury prevention practitioners with information and guidance that may be used in helping them make informed decisions about concussion management. This web site is not intended to provide medical advice and should only be used to support, not to replace the advice of a physician or other qualified healthcare professionals. We have tried our best to include accurate information in all sections of the web site, but we do not guarantee that any information is in fact accurate and true in all respects. You should always consult a physician or other relevant healthcare professionals for specific information on personal health matters,  to ensure that your own circumstances are considered. You are responsible for obtaining appropriate medical advice from a physician or other qualified healthcare professional prior to acting upon any information available at or through our website.

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