A concussion occurs when the complex network of brain cells is damaged due to the soft brain colliding with the hard bony inside surface of the skull.
It is not a “head injury” or a broken skull or a brain bruise.
The commonly used term “head injury” promotes a dangerous misconception: that there can be no concussion if there is no hit to the head. Or even worse, that there is no danger unless there is some visible injury to the head (a cut, a bump, or even a bruise), seeing stars, or a loss of consciousness, however brief. Nothing could be further from the truth.
Newton’s Laws Rule
A blow to the head can injure the brain, but so can a collision affecting the torso, or a movement that causes the neck to “whiplash” (or even when a soldier is close to an exploding bomb). Any
sudden change of direction of a person’s torso, neck, or skull can cause a concussion, because when a skull suddenly stops, or when a stationery skull suddenly jerks into motion, or when a hit to the body suddenly moves the brain (via the spine and neck), Newton’s law of inertia takes over.
(For those whose high school physics is now a blur here’s a refresher: “An object at rest will remain at rest and an object in motion will remain in motion, unless acted upon by an outside force”.)
In the case of a concussion, the object is the soft brain. The outside force is applied to the brain when it collides with the unforgiving hard inside surface of the skull. The skull also follows Newton’s law – it can change its motion suddenly when a large outside force acts upon the torso, the neck, or the head.
The jello-like soft brain floats in fluid in the skull, attached only to the spinal cord where the neck meets the skull, like a wobbly fragile ball balanced on a stick. This arrangement protects brain tissue from small undramatic changes of motion, but leaves it vulnerable to sudden changes. A hard hit to the head sends the bony skull onto the soft brain; a hit to the torso can ram the brain into the skull or the skull into the brain. Either way, the skull survives intact but the brain may not be so lucky.
These collisions aren’t simple ones like throwing a ball against the wall or playing a double bank shot in pool. When the skull and brain collide, the brain bounces back and forth, twisting and ricocheting in unpredictable ways. These collision can break or tear parts of the brain, injuring it. This is a traumatic brain injury (TBI), more commonly called a concussion.
Brains aren’t Bones
Bones are fairly simple. They’re like columns holding up a building. It is clear how they work, pretty easy to tell when they are damaged, and usually there is a way to fix the damage.
In contrast, our brains are unbelievably complicated.
There are dozens of specialized areas that pass information back and forth over billions of neurons. Damage to any area, or to the neurons connecting two areas, can dramatically and unpredictably interfere with how your brain works. And since no two collisions between a brain and a skull are the same, the outward signs of any two concussions will be different.
For example, damaging an area connected to the eyes can cause blurred vision or blindness. Or it might cause constant dizziness and nausea if the damage means that the inner ear area disagrees with the vision area. Or it might cause headaches if the right eye area disagrees with the left eye area. The severity of the symptoms will depend only partially on the amount of damage; it will also depend on precisely which areas and which brain cells have been damaged.
Some concussions can lead to depression, or anxiety, or PTSD, or mood swings (due to damage to the brain’s emotional regulation processes); others to impaired memory and reasoning, confusion, or irrational thoughts (due to damage to thinking processes); yet others to loss of coordination or balance (due to damage to motion-control processes).
Simply put, a concussion can mess up almost anything that a person does in a normal day.
There are no tests that can see the damage to the brain caused by a concussion. X-rays, MRI’s, CAT-scans, and blood tests are miraculous for other problems, but don’t help with concussions. All this makes a concussion difficult to diagnose and (at least for now) impossible to treat. The most that doctors can now do is to suggest what might give the brain its best chance to heal itself.
Lately some people and media reports have started to use the term “concussion-like symptoms”. This euphemism might lead you to wrongly believe that someone can have these symptoms without having a concussion and that the brain isn’t really injured. Because there is no “objective” test (like MRI or blood sample) the diagnosis of a concussion is based solely on the symptoms. Until a test can tell the difference between a concussion and something less serious that has the same effects, whenever someone shows “concussion-like symptoms” that person has a concussion.
“Post-concussion symptoms” is also a potentially problematic phrase. We would never say “post-fracture symptoms” when someone’s leg is still in a cast. Until the broken leg is healed, we say that the leg is broken. Similarly, until we are certain that the brain has finished its recovery (something that is very hard to judge), the phrase “post-concussion symptoms” can be misleading. As with “concussion-like symptoms”, this can cause the listener to be less careful to give the brain all the time and conditions that it needs to heal.
The real problem seems to be more psychological rather than medical. It is in a person coming to the conclusion of when the brain has healed as well as it ever will, and that brain function will not return to its pre-concussion levels. Even if this point in time could be known for sure – something that we aren’t yet able to determine – the hard thing is for the sufferer to accept that the “old me” is gone for good, and the “new me”, of diminished capacity or increased pain is permanent. When this point is reached, the phrase “post-concussions symptoms” becomes even more problematic; it continues to focus the person’s attention on the past, rather than on the future. (Going back to the leg analogy: we would never refer to someone as having “post-amputation symptoms”. Instead, we would give her the therapy and tools needed to live a full life with only one leg.)
Students aren’t Pro Athletes
So far most of the attention about concussions has involved the fate of the professional athletes in sports like football, hockey, soccer, and boxing. They are household names and their every injury is covered as breaking news. Many of the brain damaging injuries are dramatically recorded on video. And each week billions of dollars of bets are influenced by whether a player will be side-lined in the next game due to an injured brain.
They get the highest quality (and most expensive) therapy available, and are represented in multi-million dollar lawsuits by high-profile lawyers. Pro athlete concussions matter a lot.
None of this applies to a student whose brain is damaged in a check during a hockey game, a fall from a skate-board, during a minor car accident, or from a simple tumble from a bike after hitting a pothole. Medical resources are scarce, money is tight, and all too often a brain injury is not even suspected. Worse yet, while pro athletes take great care to train their bodies to minimize concussions (e.g. with neck strengthening exercises) the brains of youth and adolescents seem to be particularly vulnerable to injury.
And while the goal of the athlete and fans is return-to-play, the concussed student’s goal is the much more complex process of return-to-learn. Unfortunately return-to-learn (and return-to-ordinary-living) protocols haven’t received the attention given to those dealing with return-to-play.
Fortunately there are some common principles that apply equally to return-to-play, return-to-learn, return-to-work, and return-to-ordinary-living.
Like returning to sports too soon, going back to school or job too early can slow or even reverse the healing process. Those who have an injured brain, and their family, friends, teachers and employers, need to know this. Return-to-learn and to work should take place gradually.
To prevent further injury, the person needs to take it easy when symptoms indicate that the brain is struggling. For students this may mean taking a break from classes, putting aside an assignment, or leaving a party. Students face tremendous social and academic pressures to “push through” the symptoms. Friends and romantic partners want to have fun; teachers are wary of letting students skip tests and assignments; employers want employees to show up and work hard; and colleges and universities have rigid deadlines and criteria. Even one missed exam or deadline can mean the loss of an academic year, separating a student from friends who have moved on to another grade or graduated.
The stakes are high. On the one side a healthy brain. On the other, an uninterrupted life. The trade-offs are brutal, and it is vitally important that our institutions, particularly our schools, do everything possible to help their student achieve both goals. The list is long, but at the minimum a return-to-learn protocol should include:
- having quiet spaces in the school to give the brain a rest,
- providing alternative assessment methods and timing when a brain injury interferes with the student’s ability to take the usual tests or do the usual assignments,
- flexible teaching methods that take into account the symptoms resulting from the student’s brain injury,
- constant communication with the student, parents, and doctors to understand the student’s changing symptoms and abilities, and
- taking deliberate efforts to help the student maintain the vital social connections needed for emotional well-being, and in particular doing everything possible to keep the student with his/her cohort and program.
Reliable resources about brain injuries / concussions:
- Sports Concussion Assessment Tool
- ParachuteCanada.org (Canada’s authoritative site on concussions)
- http://www.cdc.gov/headsup/ (USA Center for Disease Control)
- http://dvbic.dcoe.mil/ (Defense and Veteran’s Brain Injury Center)
- Ontario Physical and Health Education Association Concussion protocols for schools, students, and families
- Technical paper from the Ontario Neurotrauma Foundation
- 2013 International Consensus Statement on Concussions in Sports
- Brain Injury 101 (Brain Injury Society of Toronto)