How do concussions affect the brain?

FLORA LICHTMAN: This is Science Friday. I’m Flora Lichtman. 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. Teena Shetty, a former neurologist for the New York Giants and founder of Teena Shetty MD Concussion Clinic in New York. She’s also author of the new book, Healing the Brain. Teena, welcome to Science Friday.

TEENA SHETTY: Thank you so much, Flora. I’m delighted to be here.

FLORA LICHTMAN: I’m so happy to have you. I want to start by hearing about your work with athletes. I’m sure this is what people do when you’re at parties. 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 worked with New York Liberty, WNBA. What’s your role with those teams?

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

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

TEENA SHETTY: Not particularly. [LAUGHS]

FLORA LICHTMAN: Tell me more.

TEENA SHETTY: 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.

FLORA LICHTMAN: I mean, did you have to learn about the sports to be able to diagnose what was happening?

TEENA SHETTY: 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 a contact sport.

FLORA LICHTMAN: It’s funny to imagine you in the audience with all these cheering fans, and you’re like, what just happened medically?

TEENA SHETTY: 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.

FLORA LICHTMAN: 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?

TEENA SHETTY: 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.

FLORA LICHTMAN: 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?

TEENA SHETTY: 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.

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.

FLORA LICHTMAN: Right, but it sounds like we don’t even have that criteria yet.

TEENA SHETTY: That is the problem. 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.

FLORA LICHTMAN: Is that gene also linked to Alzheimer’s? Am I thinking of the right one?

TEENA SHETTY: Absolutely, yes.

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

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

FLORA LICHTMAN: Tell me about that.

TEENA SHETTY: That’s what I learned in the training rooms and 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 collection of athletic trainers, physical therapists, neck therapists, vestibular therapists. Every single aspect of the injury is dealt with almost immediately.

FLORA LICHTMAN: Not true for most people, I’m guessing, who hit their head.

TEENA SHETTY: 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 health care system.

FLORA LICHTMAN: Everyone knows that, unfortunately. I mean, I’ve heard that there’s no scan that tells 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?

TEENA SHETTY: 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.

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

TEENA SHETTY: 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.

FLORA LICHTMAN: How does it go awry?

TEENA SHETTY: 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.

FLORA LICHTMAN: Is it like a deficit of neurotransmitters?

TEENA SHETTY: It can definitely imply and involve neurotransmitters.

FLORA LICHTMAN: Do we understand it at that level yet?

TEENA SHETTY: We do, to some extent. It’s hard to pin down. Most of our evidence in 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.

FLORA LICHTMAN: 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?

TEENA SHETTY: Exactly.

FLORA LICHTMAN: 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. I think of concussion as when you hit your head, but is that not right?

TEENA SHETTY: You do not have to hit your head to have a concussion, Flora. So 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.

FLORA LICHTMAN: Because is it about the vibration? What’s the motion that creates the concussion?

TEENA SHETTY: It’s typically a 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 harder to pinpoint. 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.

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

TEENA SHETTY: 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–

FLORA LICHTMAN: Light.

TEENA SHETTY: –noise, sound, and of course, a major element of our daily life, which is the screen.

FLORA LICHTMAN: I mean, are those the telltale symptoms– sensory issues?

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

FLORA LICHTMAN: 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.

TEENA SHETTY: 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.

FLORA LICHTMAN: Tell me more. What should I be eating if I have a concussion?

TEENA SHETTY: Protein, protein, protein.

FLORA LICHTMAN: Really?

TEENA SHETTY: 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.

FLORA LICHTMAN: Should I get the whey powder out? Is that what–

TEENA SHETTY: Absolutely. Adding protein powder to food.

FLORA LICHTMAN: Protein-maxxing.

TEENA SHETTY: Exactly. So you can be very actively engaged in improving your diet when you’ve had a concussion.

FLORA LICHTMAN: Besides diet, what are the other interventions?

TEENA SHETTY: Sleep.

FLORA LICHTMAN: Sleep

TEENA SHETTY: Sleep is the number one best medicine for a concussion.

FLORA LICHTMAN: I thought you were supposed to wake them up.

TEENA SHETTY: Absolutely not.

FLORA LICHTMAN: No.

TEENA SHETTY: 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.

FLORA LICHTMAN: Wow. That is a big change. If this is a neurotransmitter imbalance, if you’re having this deficit of neurotransmitters, does that suggest there are drugs that might help?

TEENA SHETTY: 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 norepinephrine and can be used to essentially recalibrate neurotransmitter dysfunction in the brain, 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.

FLORA LICHTMAN: Is this the standard course of treatment, though?

TEENA SHETTY: 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.

FLORA LICHTMAN: 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?

TEENA SHETTY: 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.

FLORA LICHTMAN: Can anyone with a concussion make a full recovery?

TEENA SHETTY: I would argue, yes.

FLORA LICHTMAN: You would argue. Does that mean we don’t know?

TEENA SHETTY: 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.

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

TEENA SHETTY: I think this is essentially a brain injury. 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 brain injury on the person, which it ultimately impacts their mind.

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

TEENA SHETTY: Right. And for anyone who has 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 non-specific 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.

FLORA LICHTMAN: Thank you so much for being here, Dr. Shetty.

TEENA SHETTY: It’s such a pleasure. Thank you for the excellent questions.

FLORA LICHTMAN: Dr. Teena Shetty, former neurologist for the New York Giants, and founder of Teena Shetty MD 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.