Episode 127 - Concussion Risk In Children & How To Minimize It

You're listening to the complete concussion management podcast with Dr. Cameron Marshall. Asking Cushion Doc is a show where we answer your questions about concussions, treatment and rehabilitation to help practitioners better manage these injuries. Enjoy the show. Hello everyone and welcome to Ask Concussion Doc. I'm your host Dr. Cameron Marshall and today we are talking about concussion. In children, we're going to talk a little bit about the differences between children and adults and some things that we need to be cognizant of both if we're a parent of young children who may be playing and involved in contact sports or high risk activities. And also if we are a coach or a teacher even or somebody who's affiliated in some way with contact sport and also if we're a clinician dealing with athletes who are, you know, high children under the age of 15 will say because there are some things that we need to be definitely aware of when we're dealing with this population. So let's go. First off, I'm going to talk about just differences in brain development. The first five years of your life is when your brain has 90% of the growth in terms of its brain size. We're also in this period creating massive amounts of connections. We're talking millions of new synapse connections forming every single minute. So tremendous amount of growth, learning, plasticity of the brain during early childhood development. Now you can imagine that any type of injury that's going to potentially throw this off could have some longer lasting detrimental effects. Also we have a fat molecule that lines the cells of our brain, the axons, which are kind of the long tubes in the deeper white matter of our brain. The reason why it's white is because of this fat. This fat is called myelin. Myelin helps the signals within our nervous system transmit faster. Basically, if the signal was to go along a neuron, it would go at a fairly slow rate. Now what myelin does is it allows the signal to actually jump between segments of the nerve and it actually allows it to propagate much, much, much faster. So myelin allows for faster signal transmission. But also it has a secondary effect and that is brain protection. So if you can imagine the cells of your brain being all insulated with this fat molecule, it allows the brain to be kind of in this fat type insulated capsule that can prevent it from being injured or protect it from being injured. Now in kids, myelination is not complete until you're about 15 to 17 years old and that's for the majority of the brain in the prefrontal cortex of the brain, which is involved in kind of higher order decision making, personality traits, you know, things like social processing, personality, decision making, you know, impulsivity, that type of thing is prefrontal cortex. That is not developed until after age 22 and in some cases up to 25 years old. So you're talking about myelination, this protective layer being not there until you're about 15 to 17 years old and in this case, kids can actually get concussed with less force and we'll talk about that as we go on with this session. So until we have full myelination, the brain is thought to be more susceptible to concussion, so concussion injury has been shown to affect the myelination of the brain in adults. It can actually start to demyelinate the brain, meaning that it actually starts to damage some of the cells that produce this myelin and it can actually break it down. And that's one of the kind of thoughts behind some of the long term effects around concussion is potentially damaging some of this as well as things like the blood brain barrier. Now kids also have a more kind of leaky or susceptible or malformed or incompletely formed blood brain barrier and so they're obviously more susceptible to damage to that blood brain barrier. So there's a few things that as the brain is developing, make it more susceptible potentially to concussion injuries. So trauma early in childhood could potentially have more catastrophic outcomes and potentially more long term effects. Secondly, there's less force required to cause concussions. One of the ways in which concussion can be reduced is through neck stiffness. So if we think about just from a biomechanical perspective, if you were to get hit in the head, if your neck was to be completely rigid, if your neck wasn't a movable, pliable structure, if your neck was a completely rigid thing and you were to get hit in the head and there was no movement of your head, well, because concussion is from acceleration of the brain, if you don't allow for there to be movement in the brain or in the head, you're not going to have acceleration of the brain. And so therefore a concussion cannot occur. And so one of the best ways to reduce concussion risk is by increasing stiffness of the neck. Now I don't mean neck strength because neck strength and neck stiffness are two different things. So think about this though, kids are like bobble heads, kids have big heads on small little bodies. By the age of four, a child's head is 90% fully grown. Their body is only 19% of their full body weight. By age 12, the head is now 95% fully grown and by age 12, the body weight is less than 50% fully grown. So you see we have these big heavy heads on these small little frames, which makes them more susceptible to any type of impact they're unable to stabilize as well. So it seems that in kids we have less G-forces required to cause concussions. If we look at all the studies that are done in high school and collegiate level athletes because that's where most of the studies are done, we see that the G-forces required for concussion are in the neighborhood of 70 to 120 G's. The mean peak linear force in terms of acceleration for concussion in high school and collegiate athletes is about 100 G's and the range is between 70 and 120. Now, there's only been a couple studies done in kids, but so far the studies have shown that the mean peak linear force for kids where the average age is 11 years old is 60 G's and the range is between 30 and 90. So we can see there's this shift where kids are more susceptible to getting concussed with less force. Now, is this because we have lower myelination? Is this because we have smaller head to neck ratio? Is this because we have weakness or kind of susceptibility to the blood-brain barrier? We're not really sure. It's probably likely a combination of all of the above. So this study that I was talking about is Campatolano in 2019, published in the Annals of Biomedical Engineering, finding that the mean peak linear acceleration for kids, the age range was 9 to 14 years old, was 62 G's and the range was 30 to 90. Similarly, Dawson and colleagues, also in 2019, published a finite element model, sorry, using falls, and they published this in the Journal of Biomechanical Engineering and found that children had much lower strain values than both adolescent and adult groups, meaning that younger children were sustaining concussion injuries with much lower forces than adolescents and young adults. And like I said, this could be due to body size differences, differences in brain composition, like decreased myelination. Now to make things even more difficult, and if you're a clinician who's dealt with kids, you'll understand this, but kids don't have as much self-awareness as adults and they also have limited vocabulary. So when you're trying to talk to kids about their symptoms and how they feel, they're often unable to potentially either recognize that something is wrong or off, or they're not feeling quite right, or they're unable to vocalize it properly. And this makes it very difficult for clinicians to be able to figure this out. Now even if you look at like the SCAT, which is the sideline or sport concussion assessment tool, they have a child version of that. And in the child version, they use different language, different terminology, but they also have a parent rating. Because just talking to kids, we're not likely to get the full story. And so we have to ask the parents what they're picking up, because being myself, the parent of young children, you can kind of tell when there's something off, or something's going on, or they're acting strange, or they're tired, or cranky, but kids, they can't articulate that. They're unable to do that. And so it's difficult for them to vocalize it, which makes it difficult for us as clinicians to be able to make the right calls and the right decisions. And so we have here a situation in which kids are more susceptible to these injuries, and yet they have an inability to vocalize those issues. Now, to make things even worse, there is some evidence that concussions early in life can lead to longer-standing cognitive impairments, learning disabilities, et cetera, when they get into middle school and high school. Now we have to be careful with this, because correlation and causation are two different things, and these often get misconstrued kind of in the lay public outside of kind of the scientific world. The scientific world understands that correlation and causation are two different things. But generally, when we talk about the association of two things, people tend to infer that one caused the other, and that's obviously not necessarily the case. There's other variables involved, and sometimes things that we think caused one thing were actually the reverse, right? The other thing was caused by the other thing. So for example, we have here evidence, okay? We have here evidence that people that had concussions early in their childhood tended to have worse cognitive performance in middle school and high school. Now the question is, what are the other variables that may have led to that? So let's say you have somebody with learning disability, maybe somebody with a learning disability was more likely to get concussed early on just based on differences in behavior, right? So we can't necessarily say that the concussion caused the learning disability, because it could be the other way around. Now a classic example of this is that we have an association between concussion and ADHD. And for the longest time, it was thought that concussion increased your likelihood of developing ADHD. Now studies have started coming out looking at the timing of diagnosis and finds that most of the time a diagnosis of ADHD precedes their first concussion, meaning that it's not concussion is a risk factor for developing ADHD, but it's actually that ADHD is a risk factor for getting a concussion. And so we have to be very careful with correlational type studies. Recently this month, gun and colleagues published another study examining concussion risk in collegiate athletes with ADHD, learning disabilities or both learning disabilities and ADHD and found. And this is their conclusion. In quotes, neurodevelopmental disorders may be associated with increased odds of single and multiple concussions irrespective of sex. This was published in the journal of Neurotrama. So again, like I said, be careful with correlational studies. But I think it's plausible for us to say that early concussion and early childhood could have some long lasting effects. We don't necessarily know because of the issues with causality. Sorry, my slack here is people are messaging me. Okay, but nonetheless, we have to consider that this could be a possibility. So we should take it seriously. So what do we do with all this information? Well, here's what we have so far. We have kids getting concussed with less force. We have decreased brain development up until age 15 and even in some cases, if we think about prefrontal cortex development and myelination, not until age 22 and beyond. Now we have concussions happening easier in kids. We have a different head to neck ratio. We have an inability to vocalize and verbalize when things aren't right. So these injuries may be missed and we're playing contact sports, which are potentially putting us at risk for repeated head trauma. So what should we be trying to do? I think number one is we should be trying to eliminate or at least significantly reduce concussions in kids, especially before the age of 15. Now we obviously can't totally avoid this and kids are going to be kids and some sports do not want to lift any type of rules around contact. And it doesn't matter what equipment you use either. Some parents will say, well, what helmet could I get? There would be the best. What mouth guard could I get? All of these equipment, including headgear and soccer and headgear and rugby and all of these new things that people are trying to push out there, they're all crap. They do not work. They do not prevent concussion injuries. Concussion is the brain moving inside the skull. So you can put whatever you want on the outside of the head. That brain is still going to slosh back and forth inside the skull, still going to cause a concussion. So soccer, headgear, rugby, headgear, helmets and football, hockey, whatever it is. It doesn't matter what type of helmet you get. I mean, it protects against skull fractures, so you still want a good quality one. But it will not prevent concussion injuries. And so the best thing that we can do is actually trying to eliminate or reduce the chance of contact. Carolyn Emery's group, who is a research clinician in Alberta, actually I don't know if she does any clinical work, but she's a researcher anyway in Alberta and they've done a lot of work in the area of concussion safety and trying to find ways to reduce the chances of having concussion. And they found, a few years ago, when they removed body checking from PB, they had a significant drop in concussion incidence. And the same thing they found when they removed body checking in bantam aged hockey. Now this is basically up into age, age 14. So removing body checking from amateur yuhaki significantly reduces concussion injury. Similarly, there's a big push right now in the United States from the Concussion Legacy Foundation to ban tackle football until the age of 14 when instead play flag football up until the age of 14 so that we're reducing concussion risk. And when we actually proceed into contact, our brains are a little bit more developed, a little bit more able to take these contacts and potentially not having the same type of long-term effects. The other thing that's interesting is reducing contact in practices. So if you're not willing to take contact fully out of the game, if you could reduce the amount of time you spend doing full contact drills, you can actually have a significant impact in the number of hits that you're allowing to take place. And if you reduce the sheer number of hits, you're likely to reduce the really big ones as well. Even though practice doesn't really have as much high hits as games for obvious reasons. But there's a study done by Brett Naskin in 2018. They found that if you reduced contact drills in football by 15 minutes per practice, right? So if you just said, okay, we're going to do non-contact drills and we're going to reduce contact drills by 15 minutes. So we're going to do scrimmages at the end of practice. If we're going to do that by 10 minutes each practice, that would result. So we're basically taking contact out of 25 minutes of practice. That would reduce the number of head hits that the average college athlete would get over a four-year football career by over a thousand. So that's a thousand less hits to the head that you would get over a four-year college football career just by reducing contact practice drills by 15 minutes in practice and reducing scrimmages by 10 minutes. So the big thing, the only way to reduce concussion risk is by reducing the risk of contact and by eliminating contact from the gameplay and eliminating or reducing it in practice. That's the only real way that we can have an appreciable change in our concussion risk. Now, what I was saying is that it doesn't really matter because concussions are still going to happen, regardless of what type of rules you put in place. Perfect example of this is soccer. Soccer is non-contact, right? And people will make the argument that, well, yeah, they're heading the ball. But heading the ball, actually, the G-forces in terms of heading the ball, are well below concussion threshold, well, well, well below. So most concussions are not happening from people heading the ball. Most concussions actually happen about 76% of concussions that happen in soccer are from player to player contact. If you put a bunch of people on the same field running around chasing the same ball, regardless of the rules of contact or not, they are going to run into each other, right? By making it so that they're not trying to actively run into each other through getting rid of an eliminating contact, you can reduce this. But women's hockey, for example, has no contact. It's a non-contact game, but there's still a lot of contact, right? And there's still actually a lot of concussions in women's hockey. So despite the rule changes that you may take, you are still going to have concussion injuries. Now what do we do when concussion injuries happen? The next best thing you can do in terms of prevention is actually having a good management strategy in place, okay? After concussion, we know that the brain is vulnerable. This is particularly so in kids, there's a thing called second impact syndrome. And this is when you get a second concussion before you've recovered from your first concussion. Now in rare cases, this can actually be a fatal event. We know that after a concussion, you have this drop in brain energy levels. If you get concussed again when your energy levels are low, you drop down even further, potentially to the point of causing death or permanent damage or a prolonged outcome, a worse outcome. Now we can think of this like a broken bone or like a muscle tear, right? If you break your arm, for example, right, it really, really hurts. You go to the hospital, the doctor can take an extra and say, yep, there it is. It's broken. They put a cast on it and they try to protect it and stabilize it. And they tell you, don't do anything for about six weeks because that's how long it takes the bone to heal. Now after the first seven to ten days starts to feel okay, you're like, oh, it doesn't hurt anymore, right? The pain from that fracture actually starts to get better. You're like, yeah, it feels okay. Now does that mean you can just cut your cast off and go and play your sport? No, just because it feels better doesn't mean that the bone underneath has healed, right? If you were to go back and play and you had this broken arm that had kind of healed but not quite, you're going to break it again. And it's probably going to be worse and you might even need surgery and the recovery from that is probably going to be longer because now you've created complications, right? So just because your symptoms have gone away doesn't mean that the structure itself is healed and we can think of concussion in the exact same way. A lot of times concussion, we say, well, don't go and play if you have symptoms, right? But what we know is that symptoms don't actually matter, right? Symptoms like my arm feeling better don't mean anything because same with concussion, right? Same with your broken arm, concussion. Symptoms will go away within the first seven to ten days for most people, right? Seventy percent of cases will have no symptoms after a week or so. So does that mean that you're better and you can go and play? Well no, right? The underlying brain structure is still dysfunctional, still has impairment in it. But you would never know that, right? At least with a broken arm, I can go and take an x-ray of that and I can show, oh, it's still broken, it's not healed yet. So after about six weeks when the doctor goes and looks at it, they go, okay, let's look at the fracture. If it's fine, you can go. If it's not fine, they hold you back longer. Now with concussion, we don't have anything that can see it. We can't take an x-ray of it. We can't take an MRI of it. We can, but it's not going to show us anything. Concussion does not show up on MRI, does not show up on CT, does not show up on x-ray, does not show up on any type of imaging modality that we have. The only thing that we can do for a concussion is to look at function, right? How does the brain function? Now what I mean by this is reaction time, memory, concentration, balance, ocular motor function, how fast are your eyes moving, how fast can you pick up and relay information. All of these things are how the brain is functioning. And all of these areas is where dysfunction shows after a concussion injury. So the best way that we currently have, and it's not perfect, right? We don't have any perfect way of doing this, but the best way that we currently have of being able to determine concussion recovery is saying, okay, after your symptoms have gone away, there's a few things that we would put in place. One would be physical exertion testing, because oftentimes, even though you feel better at rest, you're likely to get symptom exacerbation when we push you a little bit, when we challenge your vestibular function, when we challenge your blood pressure, your heart rate, all that stuff, you know, up, down, up, down, up, down. But then when we look at your function, reaction time, visual tracking, concentration, memory, balance, all of these things, we're likely to still see some impairments if you still have ongoing dysfunction. Now, the only way for us to know if you are back to normal is to have some sort of comparison with how you were prior to your injury, right? So the best thing that you can do as a sports organization for concussion is reduce the chances that there's going to be a concussion, particularly when you're dealing with people that are under the age of 15 years old, let's try to reduce the number of concussions we're getting. Secondly, what are we going to do when concussions happen, right? And this is where making sure that all your athletes have a yearly baseline test and not just the computer test, because this is where people go wrong, right? They do a lot of, you know, oh, we're just going to do impact tests at the start of the year in these computer tests. That's a flawed model, because these tests have been shown to have, a lot of them have, are not validated in kids for one. So they don't show really good test, retest, reliability, they're not validated for a population under the age of 12. So it's useless to do this in kids that are under the age of 12 regardless. Secondly, we're missing a lot of the components, right? We're missing ocular motor tracking speed. We're missing balance. We're missing, you know, a lot of the different, different elements that we would need for proper and full-blown concussion assessment. So having a multi-modal baseline assessment done every year for athletes, basically beyond the age of, you know, five to seven years old, you're looking at all these different things that have a good comprehensive battery. So then if an injury happens, we can use that to determine, okay, this person has now recovered and is safe to go back, right? This is our X-ray. This is our snapshot. This is our viewpoint that we don't currently have for concussion. So as a sports organization, as a parent, as somebody involved in sports, the best thing you could do is to affiliate yourself with a clinic or organization or a clinician that knows what they're doing that can run this for you and use this in the case of somebody having a concussion injury. So let's tile this up. I see that there's some questions there and I'll jump into them after on the live. But let's just tie this topic up, okay? So A, kids are more at risk for getting concussion injuries. We see that there requires less force. Now their brains are less myelated, they're developing, they have smaller head to neck ratios, it makes them more likely to get a concussion and possibly suffer long-term developmental issues. Now again, we don't have firm causality on that, but I think it's plausible to assume that there could be some deficits from getting a concussion early in life. They're also not as good at understanding or conveying what they are feeling, especially from a symptom standpoint, so they have difficulty in reporting. Now the goal here should be to reduce concussions as much as possible. Eliminating contact in youth sport I think is a good thing to do. But even with that concussion is going to happen and what are we going to have in place? I think the best thing we're going to have is well-trained concussion-specific clinicians in place that you can lean on to provide management services, education for your people. And then also encourage and/or mandate annual multimodal baseline concussion testing. And multimodal what I mean is more than just computerized testing because there's a lot of problems with just doing computerized testing, you need to have the full picture. Now, full disclosure, obviously I am the president, founder of Complete Concussion Management, Complete Concussion Management, that's what we do. We do concussion testing, we do concussion rehab, we do return to play, we do return to sport, we work with sports clubs all around the world, thousands and thousands and thousands of athletes every single year. So full disclosure, this is something that benefits me personally and our business. But the fact of the matter is this is why we do it is because the evidence is there to support this and it's the best thing that we can be possibly doing in terms of concussion management for children. I mean, you don't even have to use CCMI. I'm just saying that that's an option for you, completeconcussions.com if you are looking for a clinic. But like I said, I have skin in this game. So obviously that is my bias. Now I'm going to answer some questions over here, but in the meantime for those of you joining me on the podcast next week, we are talking injury litigation with my friend, Lewis Quail. We're going to be talking all about lawsuits and legal action that you can take with a concussion injury. What are your rights? How are you able to get what you deserve after a concussion injury? So we had him on the show a few weeks ago, people really seemed to enjoy that and so we're looking forward to having him back next week. But that's it. Let me know your thoughts about concussions and kids and other things that you've seen and things that we can do to make this better and safer for them. Cheers everybody. Thank you for listening to the Complete Concussion Management Podcast. If you like the show, please subscribe and let us know by leaving a review. If you have questions about concussion management for future episodes, submit them to our website, Facebook or even Instagram. See you next time.