Concussions: A dizzying field of research!

There are 200,000 concussions every year in Canada. If you’re not an elite athlete, your odds of having a concussion are one in 10,000. Professional athletes, on the other hand, will experience three or four by the age of 20. But since there is no way of objectively diagnosing a concussion, and those affected are notoriously reluctant to report their symptoms, the real numbers are likely higher than anyone wants to admit. What stands in the way of acceptance and proper management of concussions?
Université de Montréal
Computer-generated image of a person’s profile, holding their head where their brain is inflamed.

Imagine this: You and four of your best friends are going skiing. You spend a good while loading all your gear in the car, then you all pile in and drive two hours to the ski hill. After a few runs, you head to the restaurant at the bottom of the hill for a hot meal, then head back out on the slopes.

A half‑hour later, you don’t know who you are, who the people around you are, what time it is, or how you got to the ski hill.

So, what’s going on? You had a fall and are suffering from post-traumatic amnesia (this symptom presents in 20 percent of concussion patients). Everything feels confusing (40 percent of cases). You’re dizzy: your body won’t stop moving, the sun is blinding and despite the thick blanket of snow muffling the sound, the noise level is overwhelming (about 60 percent of concussion patients examined report these symptoms).

You have a headache (80 percent of cases). At least you don’t feel like vomiting, and you haven’t lost consciousness! (Only one in 10 concussion patients experience either of these symptoms).

In short, you have just suffered a mild traumatic brain injury (mTBI).

That’s exactly what happened to Dave Ellemberg, a neuroscientist, neuropsychologist, full professor at the Université de Montréal faculty of medicine and North America’s leading Francophone expert on concussions. But unlike him, most of us wouldn’t have known what was going on.

Photo of researcher Dave Ellemberg.
Dave Ellemberg, neuroscientist, neuropsychologist and full professor at the Université de Montréal faculty of medicine
SOURCE: Julia Marois

That isn’t surprising, since the symptoms listed above aren’t specific to concussions, and symptoms can vary from person to person.

Even if you’re not into extreme sports, you’re not necessarily immune to concussions. They can also happen when you’re doing seemingly mundane tasks, like changing a light bulb on a rickety old step stool. You may not even suffer a direct blow to your head. If the impact is violent enough for your brain to hit the walls of your skull in a pendulum motion, that’s all that matters.

This rebound effect is what characterizes a concussion: a frontal blow followed by an occipital (back of the brain) blow. During this second impact, the brain tissue is crushed against the skull, and the white matter fibres (axons) at the front of the brain become twisted. The brain becomes injured and your neurophysiological functioning will be altered.

We wanted to know more about this research, so we spoke with Dave Ellemberg, who received CFI funding through the John R. Evans Leaders Fund in March 2006.

What is your background and what research infrastructure have you acquired through the CFI?

I did my bachelor’s degree in psychology at McGill University, my master’s at McMaster University and my doctorate at McMaster University and Université de Montréal.

High-density electroencephalography system at the laboratoire des neurosciences du développement, de l’exercice et de la vision.
High-density electroencephalography system at the laboratoire des neurosciences du développement, de l’exercice et de la vision
SOURCE: Laboratoire des neurosciences du développement, de l’exercice et de la vision

From the beginning, I was interested in brain plasticity. When I set up the Laboratoire des neurosciences du développement, de l’exercice et de la vision back in 2005, I wanted to focus on mild traumatic brain injuries.

That’s where the CFI came in. We needed state-of-the-art equipment to develop our expertise, and the funding we received from the CFI helped us buy a non-invasive high-density electroencephalography system that we could use to run tests on adults and babies.

Since these types of systems require a sound-proof environment that’s free from electromagnetic interference, we also purchased Faraday cages and anechoic chambers. Over time, we brought in other equipment, including a Tucker-Davis auditory stimulation system, a visual stimulation system and an eye movement processing system, to create a multi-sensory environment.

These tools are 15 years old now, but we still use them for our research today. In fact, I recently paired the original system with a near infrared optical imaging platform. This allows us to combine electrophysiological and hemodynamic measurements so we can keep up with the latest research techniques.


Interior and exterior of one of the Faraday cages at the laboratoire des neurosciences du développement, de l’exercice et de la vision.
Interior and exterior of one of the Faraday cages at the laboratoire des neurosciences du développement, de l’exercice et de la vision
SOURCE : Laboratoire des neurosciences du développement, de l’exercice et de la vision

What are some specific examples of work you’ve done with this infrastructure?

Just focusing on our concussion work, we’ve used it to conduct analyses of multiple different age groups and concluded that adolescents present more severe cognitive deficits following a concussion. This makes adolescents the most vulnerable demographic. We were also the first team to objectively compare the impacts of concussions on the brains of women versus men.

In addition, we periodically monitor elite athletes, especially at the beginning and end of the season and when they’re injured. The risk of getting a concussion during a sports season is between 10 and 20 percent.

Are athletes the only ones at risk for a concussion?

Our scalp and skull protect us to an extent, but unfortunately anyone can get a concussion.

At the same time, there’s no need to panic: you aren’t guaranteed to get a concussion every time you bump your head or fall down while skiing. A headache might last several hours and be accompanied by dizziness or a lack of concentration, but fortunately, the injury could turn out to be superficial. Yet, we have to exercise caution.

Illustration of frontal brain activity in two subjects, one with and one without concussion.
Mapping of frontal brain activity for a so-called "control" individual (left) and a concussed individual in the test phase
SOURCE: ©Springer Science+Business Media New York 2015

So, what makes concussions special and why are they a public health issue?

Concussions are unique in that they cause lasting damage. A person who has suffered a mild traumatic brain injury is guaranteed to have some degree of neurofunctional impairment. Rehabilitation helps, but it can’t fix everything.

In my opinion, the real issue is how we approach concussions. Most people take their first concussion seriously, so they follow their doctor’s advice of resting and then gradually going back to their day‑to‑day activities. The symptoms usually clear up quickly and the majority of people make a good recovery. Unfortunately, all the evidence suggests that the damage is compounded when patients have a second concussion, because they tend to minimize the injury. They think it can’t be that bad since they got over the first one so easily.

What more can science do?

What we are trying to do with the teams in my lab is to bring science to Canadians by developing in‑school intervention strategies and raising public awareness.

We need to find ways to change people’s attitudes, and I would even go further and say we need to challenge common misconceptions. There are two big ones. The first of these is the idea of brain plasticity. Some people who aren’t well-versed in the topic think that the brain can just reprogram itself. That’s not true! Brain plasticity is real, but it has its limitations. The second misconception is that only elite athletes can get concussions — the stars, the Sidney Crosbys of the world.

We’re just wrapping up a series of five studies that look at the psychological factors that inhibit awareness of the severity of concussions. The studies draw on Canadian data from another lab that show that 80 percent of athletes only report symptoms if they’re visible.

So, what we’re looking for are the factors that keep people from talking about their injuries. Why are education and outreach not enough? What are the mental barriers?

What more can public authorities do?

In my opinion, we need people who are willing to go the extra mile. If a concussion can compromise the neurofunctional and neuroanatomical integrity of our brains, why aren’t ski and bike helmets mandatory?

Injuries are not only caused by sports, either. They can be caused by violence, like domestic violence, road accidents or accidents at work — contexts in which policymakers can absolutely intervene.

What more can we do as regular people?

Take care of your brain. You should avoid things that can contribute to brain injury, like drugs and excessive alcohol consumption. Try to live a healthy life.

And finally, what about your research gives you hope?

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There are three things that give me hope:

  • The willingness of researchers and granting agencies to collaborate more closely on the translation from basic to applied research
  • Greater willingness of researchers and media to make science accessible
  • Health care professionals’ impressive capacity for collaboration. Let me explain: When a brain has been injured and the damage persists, I put on my clinical neuropsychologist hat to understand what’s wrong. But then a whole arsenal of occupational therapists, remedial teachers, sports therapists, kinesiologists, physiotherapists, nutritionists, etc. steps in. Together, we help the patient and become allies in their rehabilitation.

Anything else you want to add?

Of course, the benefits of playing sports far outweigh any negative consequences. But with all that we know today, especially that the brain is fragile and not adequately protected inside the skull, we all have a responsibility to keep each other safe while enjoying our favourite activities. I think everyone should take better care of the most fascinating organ in their body: their brain!