How do concussions affect the brain?

The latest scientific understanding of concussions is upending treatment recommendations for recovery.

• 0:00Speaker 00

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• 0:17Speaker 01

  Hey, it's Flora and you're listening to Science Friday. Football season is upon us and a new study is making headlines. Researchers found that roughly one in four NFL players will develop CTE, a neurodegenerative disease of the brain, over their lifetime. While most of us are not professional athletes, concussions are still a relatively common injury. I mean, millions of Americans get concussions each year. The exact number is hard to pin down because many people don't seek treatment. So what are we learning about how concussions affect the brain? And how are best practices for treatment changing? Here to answer those questions and more is Dr. Tina Shetty, a former neurologist for the New York Giants and founder of Tina Shetty, M.D.

• 1:02Speaker 01

  Concussion Clinic in New York. She's also author of the new book, Healing the Brain. Tina, welcome to Science Friday.

• 1:09Speaker 02

  Thank you so much, Flora. I'm delighted to be here.

• 1:11Speaker 01

  I'm so happy to have you. You know, I want to start by hearing about your work with athletes. I'm sure this is what people do when you're at parties, like they corner you and they want to hear about what it's like to work with the Giants. You also worked with the New York Mets. I hear you work with New York Liberty, the WNBA. What's your role with those teams?

• 1:30Speaker 02

  My role historically has been to help detect, diagnose, and treat concussions as quickly as possible.

• 1:37Speaker 01

  Did you know a lot about sports when you started working with these teams?

• 1:41Speaker 02

  Not particularly.

• 1:43Speaker 01

  Tell me more.

• 1:44Speaker 02

  So I was always very intrigued by injuries in sport. And I came to sport by working actually at Hospital for Special Surgery, where I was mentored by Dr. Russell Warren, a physician for the New York Giants for many decades. And I became the neurologist for the New York Giants around 2006. And I worked very closely with them in the training room, in the locker room, as an independent neurologist who would see them immediately after they had a concussion on the field.

• 2:14Speaker 01

  I mean, did you have to learn about the sports to sort of be able to diagnose what was happening?

• 2:18Speaker 02

  Certainly, yes. And I did attend a fair number of games early on in my career so that I would become more familiar with the rules of the sport and also what could potentially be an injury in contact sports.

• 2:30Speaker 01

  It's funny to imagine you in the audience, you know, with all these cheering fans, and you're like, what just happened medically? You know?

• 2:36Speaker 02

  Exactly. And that is very much my role. Concussion, as you know, is an invisible injury. So it's very important to have a very careful history and to really understand what the patient is experiencing.

• 2:50Speaker 01

  Yeah. I mean, so you were starting out in the early 2000s. I mean, that's the time when the first links between CTE and football were being made. What was it like to be working there at that time?

• 3:02Speaker 02

  It was a fascinating time. It was a time in which there was a great deal of unknown. Some of that unknown continues to exist. But I think people are much more cognizant about concussion now and they understand the risks of contact sports and cumulative head injuries. So it was really intriguing to see that evolution over that decade.

• 3:22Speaker 01

  What do you make of this new study that we referenced in the intro? That one in four players will develop CTE in their lifetime?

• 3:28Speaker 02

  So the study has a very disturbing result, which is very provocative. I think as neurologists and scientists and physicians, we find it a problem that's very confounding because CTE, as you're aware, is a postmortem pathologic diagnosis in which it's very difficult to form a correlation with living people who are having concussions. So we have to weigh and measure the risk of each concussion when we decide if a patient is cleared or an athlete is cleared to return to play, also knowing that this very frightening risk of CTE may or may not exist for that player.

• 4:08Speaker 02

  So we want to basically inform them of the risk of their specific concussion and weigh in the long-term risk of cumulative head injury. We don't want to be overly paranoid about CTE without having a clear understanding of what the risks for it are. So right now, for scientists and neurologists and neurosurgeons, CTE is a great unknown, meaning we cannot say to a patient, you are not at risk of CTE. We have to say to a patient, you could theoretically be at risk for CTE. But we have to measure in objective criteria and clinical evidence to determine if they're clear to return to play.

• 4:50Speaker 01

  Right. But it sounds like we don't even have that criteria yet.

• 4:53Speaker 02

  That is the problem.

• 4:54Speaker 01

  Yeah.

• 4:54Speaker 02

  Exactly. That is exactly the problem, Flora. And so we don't have tests in which we can say to someone, you are clearly someone who is at a higher risk of developing CTE, except for genetic testing, such as the APOE mutation. So if someone came to us with a genetic test that showed that they had an APOE mutation and they had multiple concussions, then we would begin to have this conversation where, you know what? You may be at risk for CTE and we should really reconsider whether contact sports is the right career or sport for you.

• 5:28Speaker 01

  Is that gene also linked to Alzheimer's? Am I thinking of the right one?

• 5:30Speaker 02

  Absolutely, yes.

• 5:32Speaker 01

  So are these athletes treated differently for concussions than the general public is?

• 5:37Speaker 02

  I think the speed and the acceleration of treatment for the injury is very different in professional sports.

• 5:42Speaker 01

  Tell me about that.

• 5:43Speaker 02

  That's what I learned in the training rooms, in the locker rooms of the New York Giants, which is that when a professional athlete has a head injury, there's a team responsibility to really diagnose that right away and to bring it to medical attention immediately. So the athlete is triaged almost within minutes into the hands of the team doctor, the independent specialized doctor, myself as a former independent neurologist for the New York Giants, as well as a, you know, collection of athletic trainers, physical therapists, neck therapists, vestibular therapists. Every single aspect of the injury is dealt with almost immediately.

• 6:24Speaker 01

  Not true for most people, I'm guessing.

• 6:27Speaker 02

  Absolutely not. In fact, the concussion patient is in a very unusual position, Flora, where they not only have to self-advocate for an invisible injury in which they physically often appear completely fine. So they have to explain to people that they have a brain injury. And they then have to seek and identify expert help, which can be very challenging in the current healthcare system.

• 6:52Speaker 01

  Everyone knows that, unfortunately. I mean, I've heard that there's no, you know, scan that tells you if you've had a concussion. The FDA recently approved a blood test to diagnose concussion. Is that reliable? What do you make of that?

• 7:06Speaker 02

  The blood test is something which is really more relevant to patients who have blood in their head. So it's not really concussion or mild traumatic brain injury in which its value is felt. It's really in the more moderate to severe injuries, which are complicated by blood in the head. And that's not traditionally or historically what happens to athletes, whether professional or otherwise. They usually experience more of a mild traumatic brain injury, quote concussion, in which the brain MRI, as you alluded to, or the CT scan is completely and totally normal.

• 7:42Speaker 01

  I mean, you write that a concussion is a functional injury, not a structural one. What does that mean?

• 7:49Speaker 02

  It really means that it has to do with the connections of the brain. It has to do with the network of the brain. The brain has so many complex heterogeneous structures, and they all have to work together. We know that our frontal lobes contain our executive function, oftentimes our personality and inhibition. Occipital lobes contain things like vision and balance. Temporal lobe contains memory. These are such complex functions of the brain, and they all have to work together. And that connectivity goes awry when you have a concussion.

• 8:22Speaker 01

  How does it go awry?

• 8:23Speaker 02

  It has to do with the fact that those connections are modulated by chemicals as well as neuronal synapses. And those synapses and connections are dysfunctional after concussion, somewhat dysfunctional. So you can perform your activities of daily living. You're not impaired in functions of the brain, like motor function or specifically walking or movement or speech. It's much more subtle and more nuanced.

• 8:50Speaker 01

  Is it like a deficit of neurotransmitters?

• 8:53Speaker 02

  It can definitely imply and involve neurotransmitters.

• 8:57Speaker 01

  Do we understand it at that level yet?

• 9:00Speaker 02

  We do, to some extent. It's hard to pin down. Most of our evidence and science is in animal models. But the deficit has to do with both a metabolic energy crisis to do with glucose metabolism and thereby also neurotransmitters like serotonin, dopamine, epinephrine.

• 9:18Speaker 01

  So you're not getting enough glucose metabolized and therefore the downstream effect is that you're not getting these neurotransmitters that are really important to making your brain work?

• 9:26Speaker 02

  Exactly.

• 9:27Speaker 01

  I've been reading about Coast Guard rescue crews and jet fighter pilots who might be unwittingly suffering from concussions and brain injuries on the job. You know, I think of concussion as when you hit your head, but is that not right?

• 9:43Speaker 02

  You do not have to hit your head to have a concussion, Flora. You can hit your head or neck. I cannot tell you how many whiplash concussions we see. And neck is the most oft ignored piece of concussion treatment.

• 9:56Speaker 01

  Because is it about the vibration? What's the motion that creates the concussion?

• 10:01Speaker 02

  It's typically rotational acceleration, deceleration movement that creates a concussion because the brain is very soft. It's sitting in our skull, which is hard. And there's water, cerebrospinal fluid between the two. But when there is that kind of acceleration, whether or not it is a vibration is kind of harder to to pinpoint, you know, to what degree a vibration can be so profound that it can cause that kind of forceful acceleration, deceleration that causes a concussion. But these kind of movements, including whiplash, can really injure the brain temporarily.

• 10:37Speaker 01

  Why do some symptoms of concussion vary so widely among people?

• 10:42Speaker 02

  As neurologists, our job is to localize symptoms to a specific area of the brain. And we were unable to do that in concussion. So because it's not specifically a temporal lobe injury, which would theoretically lead to a memory problem, a deficit localizable to the hippocampus, the part of the brain that contains memory, it has to do with the connections between the different lobes of the brain. And that's why the symptoms are very nonspecific. And so what we see is that because it's a connectivity injury, the brain essentially becomes more sensitive and it has difficulty with environmental issues to do with light, noise, sound, and of course, a major element of our daily life, which is the screen.

• 11:23Speaker 01

  I mean, are those the telltale symptoms, sort of sensory issues?

• 11:27Speaker 02

  Often, often. The most common symptoms are often headache and dizziness. But when you explore the symptoms further with a patient, many of my patients have sensory issues that they find difficult to navigate in daily life.

• 11:39Speaker 01

  I have to take a break. But when we come back, I want to talk about how concussion treatment is changing. I gather it's time to ditch the cocoon.

• 11:47Speaker 02

  Absolutely.

• 11:55Speaker 03

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• 12:31Speaker 01

  So how has the standard course of treatment changed for concussions? Because I remember being told to go into a dark room and get under a blanket.

• 12:42Speaker 02

  Cocooning has been left behind. And we now know that we must take an active interventional approach to concussion, which involves lifestyle modifications, which are not cocooning, but are a very prescriptive approach to things like diet, sleep, and screen time.

• 13:02Speaker 01

  Tell me more. What like, what should I be eating if I have a concussion?

• 13:05Speaker 02

  Protein, protein, protein.

• 13:06Speaker 01

  Really?

• 13:07Speaker 02

  Absolutely. Protein is enormously helpful for the head and for headaches. And this is not well known. And it really should be prescribed much more.

• 13:19Speaker 01

  Like, should I get the whey powder out? Is that where you're like?

• 13:22Speaker 02

  Absolutely. Adding protein powder to food.

• 13:25Speaker 01

  Protein maxing.

• 13:26Speaker 02

  Exactly. So you can be very actively engaged in improving your diet when you've had a concussion.

• 13:32Speaker 01

  Besides diet, what are the other interventions?

• 13:34Speaker 02

  Sleep. Sleep is the number one best medicine for concussion.

• 13:38Speaker 01

  I thought you were supposed to wake them up.

• 13:40Speaker 02

  Absolutely not.

• 13:41Speaker 01

  No.

• 13:41Speaker 02

  In fact, I would forbid that once someone is out of the danger zone in which they're worried about things like blood in their head or brain herniation. These are not complications we see in mild traumatic brain injury patients. In fact, sleep immediately after the concussion is absolutely the best thing that they can do for themselves.

• 14:03Speaker 01

  Wow, that is a big change. You know, if this is a neurotransmitter imbalance, like if you're having this sort of deficit of neurotransmitters, does that suggest there are drugs that might help?

• 14:17Speaker 02

  That's a fascinating question. So we're all aware of drugs, basically psychopharmacologic drugs that affect neurotransmitters. So the old ones used to be known as tricyclic antidepressants. The newer ones, which are no longer new, but are widely used, are SSRIs. These drugs are not typically used in acute concussion patients. Having said that, the older psychopharmacologic medicines like tricyclic antidepressants are very much involved in pathways of dopamine, epinephrine, and nor- noradrenaline and can be used to essentially recalibrate neurotransmitter dysfunction in the brain

• 14:59Speaker 02

  and also concomitantly to help with sleep and to help with headache. So yes, there is a role for those in very low doses that are very safe, even for children, and can have an enormous benefit because they can really improve bedtime and sleep in acute concussion patients. And they can also eliminate their headache.

• 15:23Speaker 01

  Is this the standard course of treatment, though?

• 15:26Speaker 02

  Not necessarily. I think a lot of concussion experts that are neurologists are more comfortable using these drugs. Neurologists use medicines that are typically anticonvulsants or antidepressants because those medicines are also for brain dysfunction of other kinds. So we tend to be more comfortable with them.

• 15:48Speaker 01

  I mean, you're making this distinction between neurologists and, I'm assuming, other doctors. Do you feel like doctors are prepared to treat concussions? Is this a unit in med school?

• 15:58Speaker 02

  It historically has not been a unit in med school, and that's part of the problem. I'm not familiar with current curriculums, but I think now it's being taught more clinically in the training period for physicians when they're in residency. It's definitely taught in sports medicine residencies. They're definitely given a lot of education and training on concussion and specifically return to play.

• 16:20Speaker 01

  Can anyone with a concussion make a full recovery?

• 16:23Speaker 02

  I would argue yes.

• 16:25Speaker 01

  You would argue? Does that mean we don't know?

• 16:28Speaker 02

  The reason I use the terms "I would argue" is because my personal belief from having treated so many thousands of concussion patients and worked with so many athletes is that the concussions that are left to linger and are not treated and are not given this active interventional approach are the ones that may develop this phenomenon, which is post-concussive syndrome, because they really weren't recognized, diagnosed, and treated properly.

• 16:53Speaker 01

  You take a humanistic approach, it seems like. Can you talk about that and why you think that's important?

• 16:58Speaker 02

  I think this is essentially a brain injury, right? And so therefore, one cannot ignore the mind-brain component. And so I think that's led me to really have a more holistic, integrative approach to understand the impact of the brain injury on the person, which, you know, ultimately impacts their mind.

• 17:22Speaker 01

  Yeah, I mean, I guess there are a few injuries that affect your personhood more than a brain injury, right?

• 17:28Speaker 02

  Right. And for anyone with a concussion, it's a very difficult injury to have. And many people struggle with that because they think, well, this is an injury that you can't even see on a scan and the symptoms are very nonspecific and subjective. But the reality is, Flora, that they really affect the person's daily life. They affect their identity. It can affect their personality. And so it can be a devastating injury for people to have. So to ignore the mind-brain component can make it very difficult for the doctor-patient relationship, in my opinion.

• 18:02Speaker 01

  Thank you so much for being here, Dr. Shetty.

• 18:04Speaker 02

  It's such a pleasure. Thank you for the excellent questions.

• 18:07Speaker 01

  Dr. Tina Shetty, former neurologist for the New York Giants and founder of Tina Shetty, M.D. Concussion Clinic in New York City and Associate Professor of Clinical Neurology at Weill Cornell Medical College. And don't forget, author of the new book, Healing the Brain.

• 18:29Speaker 01

  This episode was produced by Shoshana Buxbaum. Do you have a burning science question for us? Give us a call, 877-4sci-fires is our number. Our listener line is always open. I'm Flora Lichtman. We'll catch you next time.