What is a Concussion? | Concussion Patient Education Series | Ep. 1

how many of you think that concussion is bruising of the brain hello and welcome to our channel i'm dr karen marshall better known as concussion doc on social media and i am here to help you better understand concussion injuries in this video i'm going to dive deep into the science around what a concussion actually is what happens inside your brain when you get a concussion and why do you feel the way that you do this video is part of a new video series designed specifically to help concussion patients optimize your recovery and heal your brain for good so whether you've just had a concussion and are looking for how to best recover or you had a concussion 10 years ago and you're still dealing with symptoms this video series is going to help you to understand why because once you understand the why and why you're still feeling the way you are well then you can fix it so if you're new to the channel please be sure to subscribe like this video leave any comments or questions you have below i will do my best to get back to you and answer them if there's something you'd like me to like to see or something you'd like me to cover please let me know also if you know somebody who you think would benefit from this content please be sure to share it with them because knowledge is power and sharing is caring also before i forget there are some links below in the description for various resources and things that are there to help you with your recovery so be sure to check it out i host webinars all the time we have recovery tips and more we're always trying to do things to help patients get better so be sure to check that out if you need a little bit more help and guidance so this is the first video in this series and i'm going to lay this as the foundation for you then throughout the rest of the series i'm going to spend my time teaching you how to fix these issues and how to recover from concussion injuries so let's dive in so first how many of you think that concussion is bruising of the brain right and i wouldn't even fault you for thinking that because if you google concussion and look at images this is what you see right i googled concussion and this is what i found there's bruising here direct injury and we used to think of concussion as something called a coup contra coup injury and it the brain hits the inside of the skull it bounces back and it hits the back part of the skull and it you know damages the outer part of the brain well actually that's not the case concussion is actually a temporary energy deficit temporary energy deficit post concussion deficits occur with very little if any observable pathology meaning that the brain remains intact so if you get an mri or a ct scan it's likely to be normal right and you might be confused by this be thinking like i don't feel normal i feel terrible there's got to be something wrong with my brain well there is because it's a functional injury it changes how the brain functions but the structure of the brain which is what you see on mris and ct scans remains intact so there's no damage so everything looks normal and this is what's so confusing about concussions because oftentimes even doctors will dismiss this they'll say well your ct scan is normal and therefore everything is fine and go home but that's just a poor understanding of what concussion actually is symptoms often resolve completely over time in fact most cases symptoms resolve completely over the first couple weeks right seventy percent of cases symptoms will be gone within the first two to four weeks after injury for the other 30 percent symptoms can linger on and we're going to talk about that more in future upcoming videos but right now we're talking about what happens right at the point of impact so this suggests that it's a temporary dysfunction if all the symptoms go away it doesn't mean that that usually indicates the brain doesn't have structural damage to it right it's a change in function that resolves over time and the reason is because temporary energy deficit so there's two phases to a concussion injury the first one is called the excitatory phase so this is what happens in the first seconds to minutes after injury the second phase is called spreading depression and this is actually the drop in energy that occurs and so we're going to talk about each one of these phases because it's very important to understand what's going on because then you can kind of make sense of whoa that's why i felt like that and that's what's going on now that it's been however long however long it's been so first let's have some anatomy this is the brain right here if we look at the brain and cut it in half you would see two different tissue layers this deeper part here is called the white matter and then this outer part is called the gray matter and they're actually part of the same cell so this is what a brain cell looks like this is called a neuron and the outer part here is the cell body this is kind of where the nucleus is and there's a bunch of different stuff inside here that help the workings of the cell this is called the axon which is a long tail and this is where the signal gets sent from the cell body down to the end and then neurotransmitters release which pass that signal on to the next brain cell in the chain which then takes that signal and passes it on and does its thing right so this is how communication happens in our brain it's an electrical system that's constantly you know moving signals around and that's what allows us to do everything it is that we do so your nervous system is super super complex and super super interesting now why is this important well this layer here this this these little globules here this is called myelin and it's white it's fat so these are fat cells here and this allows the signal to move really really quickly so these fat cells actually allow the signal to jump between these little called nodes and allows the signal to jump really really fast and that's what allows the signal to be lightning quick within our brains and that allows to have really quick reaction time and all these other things and the this fat layer is the white layer this out here is the gray matter which is the cell bodies right so this is how the structure is made up now the interesting thing here and what's super important for a concussion is that these two tissue layers are different densities so they accelerate and decelerate at different rates so concussion used to be thought of as the brain smashing against the inside of the skull creating a bruise and damage to the actual outer part of the brain but actually it's damaged to the inner part of the brain because what happens is because these two tissue layers are different densities when the brain gets hit and the brain moves around inside the skull what's happening is it's accelerating and decelerating and these layers are actually shearing across one another and pulling apart and stretching so that quick stretch of the brain cells is actually what creates the concussion injury it's not necessarily the hitting of the of the brain on the skull although that can happen too in more serious injuries but it's actually this quick stretching of the brain cells deep inside now to understand why this happens we have to take a look first at normal brain function so here is our neuron and it sends signals through this process called action potentials so action potentials you can see here this is the voltage and this is in millivolts so the resting membrane potential of a neuron is minus 70 millivolts as a signal comes in if the signal is strong enough it'll it'll increase the voltage inside the neuron if it hits 55 negative 55 millivolts that neuron will fire and pass that signal on if we don't get enough of a signal coming in it won't hit 55 and basically that signal will die out so we're only passing really good strong current information right so if we don't get enough or a weak signal we might not actually fire so this can be thought of something like if i'm going to touch your skin if i'm touching it you know with a certain firmness you're going to feel it but if i come off real slightly all of a sudden you're not hitting enough for the threshold to be released you may not feel that particular sensation so that's kind of the easiest way to describe it so this is all done from this electrical gradient system so we have this negative 70 millivolt we get a signal coming in if it's strong enough boom the neuron will fire and that'll pass the signal to the next neuron it'll release neurotransmitters that next neuron will get those neurotransmitters and if there's enough of them it will hit its negative 55 millivolt threshold and it will fire and then you have your action potential okay now this is all done via ion exchange you can see back here in this picture you have sodium ions coming in potassium ions going out so this exchange in ions is actually what leads to this change in voltage and this action potential so we have something called a concentration gradient so inside let's say this is inside of a brain cell inside the brain cell we have high amounts of potassium on the outside of a brain cell we have low amounts of potassium so therefore the concentration gradient is such that the potassium wants to get out of the cell because it likes to go where there's not a lot of it so things like to spread out and have even distribution so if you have a high amount of potassium inside the cell and a low amount of potassium outside the cell that potassium is going to want out of the cell similarly we have a high amount of calcium high amount of sodium on the outside of the cell it wants to get in so anytime there's a little opening in this neuron then this will leave and these will come in and that's actually what happens in an action potential when neurotransmitters come in to a brain cell their little channels will open on the axon potassium will go out sodium and calcium will come in that will raise the membrane potential and if it raises it enough it'll fire so this is the communication line so signal comes in ions exchange if it hits the threshold it fires all right so this requires no energy this is a passive system so in order for a neuron to fire it actually doesn't require energy where it requires energy is to reset so because this concentration gradient is such that potassium wants out how do we get it back in because once that neuron fires we're actually going to have to reset this in order to restore the right concentration the right balance right and that actually is what requires atp which is our energy molecule we have to push potassium back into the cell and we have to push sodium out of the cell to reset our balance and that requires energy because we're pushing uphill we're pushing against where things want to be and that requires the energy so now how do we frame this with concussion well like i said concussion is due to acceleration deceleration so you can see here when this person is hit the brain goes through this fluid wave so you can see this kind of wave come over the top of the head back and forth the brain sloshes back and forth well as that's pulling up you can picture all these axons actually getting pulled apart and when they get pulled apart that's where things happen so they don't get pulled apart to the point of breaking but they get pulled apart far enough that you get ion exchange so you can think of an axon like a long tube right so if you think about the axon like a long tube that's solid this doesn't really make sense but what an axon actually is is a long tube with a bunch of holes in it now these holes are small enough that things aren't going in and out but when you get an acceleration or deceleration you actually get a stretching where these holes become elongated and with that you get potassium going out of the cell and sodium and calcium coming into the cell so what do you get action potentials so all a concussion is and you want to think about it very simplistically is when the brain gets hit and these brain cells stretch if there's enough acceleration they'll stretch and when they stretch the pores on the outside of the axon will open up and you'll get an ion exchange so all a concussion is is millions and millions of brain cells that get tricked into thinking that they've all received an action potential at the same time because of this stretching and ion exchange so what happens is boom electrical chaos inside the brain this might cause you to see stars right you're not seeing stars it's just random discharge of neurons firing in your visual cortex right you might go unconscious you might have balance issues you might be confused you might slur your speech you might have a blank stare because there's so much information going on that you're not taking it in you might forget the whole incident because none of the memories are going into the right spot because everything is just chaos okay so that is the excitation phase right so we think here we've done this and then we have to now use energy to rebalance it so this is the second phase so the excitation is a passive phase there's no energy needed it's just chaos for a few seconds to minutes and then it kind of calms down no i think i'm okay okay you know you might ask questions for you know in next couple hours you might be a little confused for a while but after the next you know first few hours things kind of calm down and some people it calms down after the first five seconds right that doesn't mean that everything's done now right but the first part's done now the second part is the spreading depression so this is a picture this is a very famous picture from concussion research you have here an action potential releasing neurotransmitters to this is the cell body here so it's a rudimentary picture and you have calcium coming into the cell and potassium getting out of the cell right so this is our action potential now the interesting thing here is calcium is actually the biggest issue calcium gets into the cell and gets into our mitochondria our mitochondria are our energy production parts of the cell so they actually are the ones that make atp atp is our energy molecule remember what do we need atp for we need atp to reset our ion balance so what we've had here is a is this insult which has caused stretching of the brain cells which has caused ions to exchange which has caused all the brain cells to fire well now we need to reset that balance so that our brain can work properly but we need energy to do it the problem is calcium at the same time comes into our cell gets into our mitochondria and prevents us from making energy so because we can't make energy and we're burning a lot of it you get this very quick drop in energy so if you've ever had a concussion and i'm sure most people watching this have or know somebody who has you are get very very tired you get very very fatigued it's because you're burning more energy than you're producing so what it looks like is this so this is an animal study here and you can see here this is atp so this is our energy this is time within one minute our energy levels are already starting to drop 10 minutes 30 minutes two hours we hit significant difference six hours we hit our peak low and then we gradually restore back up now this is in a mouse so in a mouse it takes a full five days to get the energy back up to where they were so this is 120 hours five days there's no more star there which means there's no more significant difference from the sham so in a mouse model a concussion takes five days to fully recover the problem is we can't measure atp directly in humans but we have a special technology called magnetic resonance spectroscopy these are research tools so unfortunately you can't just go and get one of these but it's an interesting research tool because this shows atp in humans somewhat because we actually have something else that correlates with atp so we're not measuring atp directly but it correlates with atp and what you see here if you look at the black bars this is a control group this is three days after injury we have significant difference 15 days after injury we still have significant difference 22 days after injury we still have significant difference and then 30 days after injury you can see that single star has now disappeared so we have no more significant difference so in the mouse model concussion took five days to recover from this metabolic functional temporary energy deficit in humans it takes about three to four weeks and most people will be asymptomatic within that three to four week time so concussion in summary is a temporary energy deficit it causes an excitatory phase right after acceleration in the next video we're going to talk about how much acceleration is required to actually cause a concussion injury and then when that acceleration happens and those brain cells stretch out you get an ion exchange you get firing of brain cells you get this chaos that happens within the brain all sorts of symptoms that go aside with concussion and then you get the fatigue and the symptoms that come on a little bit later neck pain headache visual disturbances cognitive issues all these things that energy tends to come back within three to four weeks so the question is if you're still having symptoms why if the brain recovers in three to four weeks why are you still having symptoms and that's what the rest of this video series is going to explain so the first part we're going to talk about what a concussion is we've already done that then we're going to talk about how much force it takes then how do you know and what do you do in the first few days to optimize your recovery and then in future videos we're going to talk about what if you're still having symptoms why do you still feel this way if the brain itself on the functional standpoint has recovered and the reason there's actually a few reasons is is actually treatable and that is the good news so like i said join us for the next video i will be putting these out on an ongoing regular basis so be sure to subscribe to the channel if you haven't already activate the notification bell so that you get notified when i do release the next videos in this series if you like this please be sure to like it if you have any questions about what i covered today be sure to write them in the chat and the comments below and i will try to do my best to get back to you if you need help with your recovery and you need a little bit of guidance and you want to know exactly what you can do then be sure to check out the links in the description below there's all sorts of stuff for you that can help you out so until next time thank you for joining me and i hope you start to feel better soon you

Channel: Complete Concussion Management

Views: 33,385

Keywords: what is a concussion, what happens when you have a concussion, concussions explained, concussion symptoms, concussion recovery, concussion treatment, do i have a concussion, traumatic brain injury, tbi, concussion, brain injury, head injury, head injury treatment, bruised brain, how do concussions affect the brain, brain injury rehabilitation, brain injury rehabilitation program, concussion recovery time, concussion recovery tips, cte, concussion injury

Id: QWVwAuqO2DM

Length: 18min 47sec (1127 seconds)

Published: Wed May 04 2022