By Ashwin Aggarwal

The National Football League (NFL) has been put under the spotlight recently for an alarming increase in brain injuries to past and active players. Players, fans, and coaches are now much more aware of the repercussions of repeated concussions and what they can lead to. Research about chronic traumatic encephalopathy (CTE), a progressive brain disease caused by repeated blows to the head and repeated concussions, has become an important topic in sports medicine. This disease can lead to memory loss, erratic behavior, and depression. 

CTE is commonly seen in boxers and American football players. This disease is not able to be diagnosed in a living person due to the microscopic examinations of brain tissue that are needed to identify the protein and abnormalities that characterize the disease. Regarding brain injuries and CTE, Oakland Raiders legend Bo Jackson said in an interview with USA Today “If I knew what I knew now…  I would have never played football.” Even with the increased awareness of the consequences of hard hits in football, concussions still happen.

Most recently, in an NFL game on September 25 against the Buffalo Bills, Miami Dolphins quarterback Tua Tagoviola went down with what was widely believed to be a concussion after being tackled by Bills linebacker Matt Milano. When Tagovailoa stood back up, he looked to be very unstable, and he nearly fell back down to the ground. Tagovailoa was then taken out of the game and into his team’s locker room to undergo the NFL’s concussion protocol test. If the player is deemed to have a concussion via MRI or symptoms, he must follow the concussion protocol.

The NFL concussion protocol consists of five phases. After completing a phase without an increase in symptoms, the player is only then allowed to move on to the next phase. 

Phase I: The player is told to rest and is allowed to begin gentle stretching if they are not experiencing any symptoms.

Phase II: Players should begin cardiovascular exercise, dynamic stretching, and balance training. At this point, aerobic exercise is the most exertion a player should do.

Phase III: During this phase, a player can begin football-related exercises. The player is allowed to practice with the team in sport-specific exercises for up to 30 minutes while being monitored by the training staff. However, the player is not permitted to engage in any contact exercise. This includes tackling other players, practice dummies, or practice sleds.

Phase VI: The player is now allowed to practice with the team in any non-contact practices. All neurological components must return to the baseline level before the player is allowed to progress to the next phase.

Phase V: After the player can demonstrate the ability to withstand all non-contact practice, such as meetings, weight training, and conditioning, without showing recurring symptoms, and his neurological testing has returned to baseline, the team’s physician may conclude that the player/patient’s concussion has been resolved. The physician can now allow the player to participate in all team activities, including contact.

Tagovailoa came back into the game after halftime. However, his play wildly deteriorated in the second half of the game, as he threw 18 passes but only completed four. After he threw an interception, he was replaced by backup quarterback Teddy Bridgewater. The next day, the Dolphins announced that Tagovailoa was not undergoing concussion protocol and that he stumbled in the game versus the Bills due to the hit flaring up a previous back injury. The decision-making of the Miami Dolphins training staff was widely criticized and led to an investigation by the NFLPA (NFL Players Association) of whether or not the Dolphins properly followed concussion protocol. The NFLPA deemed that the Dolphins did, in fact,  follow protocol.

However, the Dolphins were matched up against the Cincinnati Bengals the following Thursday, leaving Tagovailoa only four days to fully recover from the game against the Bills. In the second quarter of this primetime game, Tagovailoa was sacked and hit the turf field with his head. This time, there was no doubt that Tagovailoa had suffered a concussion. He demonstrated a “fencing” response: a reaction caused by head trauma. He was unconscious, on his back, with his hands in the air, and with his fingers bent in an abnormal way. He was quickly put on a stretcher, carted off the field, and taken to the hospital.

The fact that Tagovailoa was allowed to play in this game led to enormous outrage among players, fans, and the NFL itself. The problem wasn’t that the Tagovailoa had passed the concussion protocol test; the problem was with the test itself. Shortly after this incident, the NFL added what is now known as the “Tua Rule.”

The Tua Rule is an update to the NFL’s concussion protocol, agreed upon by both the league itself and the NFLPA. Under this updated protocol, ataxia (gross motor instability) has been added to the list of symptoms that mandate the immediate removal of a player from a game. Ataxia has been added to a list of symptoms that already includes unconsciousness, confusion, and amnesia. 

John Hopkins Medicine defines ataxia as “a lack of balance, coordination, and trouble walking. Ataxia may affect the fingers, hands, arms, legs, body, speech, and even eye movements.”

Tagovailoa was diagnosed with a concussion and went through concussion protocol. He sat out through Weeks 5 and 6 and played against the Pittsburgh Steelers in Week 7, four weeks after his initial injury, and three weeks after his second injury. 

Tua Tagovailoa playing for the Miami Dolphins.                Photo credit: Tennessee Titans via Wikimedia.

A recent case of CTE is Pro Bowler Demaryius Thomas. Thomas was best known as a receiver on the Denver Broncos, and he even won a championship with the Broncos in Super Bowl 50 on February 7, 2016. He passed away at the young age of 33, on December 9, 2021. He was diagnosed posthumously to have Stage Two CTE.  

However, Thomas’ death was not sudden. The New York Times article “An N.F.L. Star’s C.T.E. Diagnosis Offers Only Partial Insight” depicts the decline of Thomas’ health. Even on the day he won the Super Bowl, he wasn’t able to go out and celebrate with his team because his head was hurting so badly. During the Super Bowl game versus the Carolina Panthers, Panthers linebacker Luke Keuchly collided with Thomas, which led to Thomas holding his head in pain, even after the game. Later on in his life, he told his mother that he had lost his peripheral vision. All these factors can stem back to head trauma and brain disease.

However, Tagovailoa and Thomas’ cases are proving to be a recurring theme, and not just in the NFL. Tagovailoa isn’t the only one who has suffered from head injuries playing football. Concussions in younger athletes, more specifically high school and NCAA football players, have been increasing. Out of the 300,000 concussions that high school athletes suffer every year, football accounts for 67,000 of those (22.3 percent). 

A single concussion isn’t life-threatening. However, returning to play contact sports without allowing the brain to fully recover is what doctors are fearful of. Repeated concussions can lead to dementia and movement disorders, such as Alzheimer’s and Parkinson’s diseases. Parents’ fear of their children receiving life-altering brain damage has caused the number of high school students signing up to play football to decrease nationwide.

According to data collected from 2008 to 2019 from the National Federation of State High School Associations (NFHS), the number of youth athletes (ages 6 to 18) participating in contact football has decreased by 24 percent (from 2.5 million to 1.9 million), and the numbers are continuing to fall. The increase in the awareness of brain damage due to concussions and the decrease in football participation in all levels of competition throughout all ages is clearly related to the overall risk of playing contact football. 

The National Institutes of Health (NIH) and the NCAA funded a study conducted with helmets from Riddell, the sports equipment company that manufactures helmets for football teams, to track the frequency of impacts to the head that a player receives. Riddell’s advanced helmet, the Revolution IQ Hit, collects data on impacts to the head.

Riddell’s Revolution IQ Hit sensors
Photo credit: MIT Technology Review.

This Riddell football helmet is equipped with six accelerometers, the sensors, in its liner. The red circles show where the accelerometers are placed. The study equipped football teams from universities such as Virginia Tech and Dartmouth College with the new helmets. These accelerometers measure the magnitude, location, and direction of a hit to the head. Then, they send this data over to a computer. 

The results from the study shined a new light on just how many hits to the head football players receive over a season. The researchers found that players receive, on average, 1400 to 1500 hits to the head per season, six per practice and 14 per game. Furthermore, the data received from these helmets showed a correlation between the position of a player on the team versus the number and intensity of hits to the head. Linebackers and linemen are players who are often attacking the line of scrimmage the most, receiving the most number of hits per game. However, running backs are hit less frequently but with a greater magnitude than other positions.

Having sensors in helmets can lead to a long-term improvement in monitoring the health of players. The sensors in these Revolution IQ Hit helmets measure the acceleration of the head, both linearly and rotationally. The force received is then measured in “g-force,” with one g equal to the force of gravity. The threshold for a concussion is defined as 98 g. However, minor hits that are below this threshold still have a significant impact on brain health. According to the data shown from the study, 90 percent of concussions go undiagnosed because the player that was hit was capable of still playing. This information is extremely valuable for coaches and trainers, as the alerts on the helmet system can be customized so that team physicians on the sideline can be reported when a player on the field has exceeded a certain number of hits per practice or game, or when his collected g-forces to his head are too high to keep playing. The use of these helmets in high school football can help protect students from severe brain damage that could cripple them later in life. 

The difference between a normal brain and a brain with CTE.
Photo credit: Boston University Center for the Study of Traumatic Encephalopathy.

My father Dr. Atul Aggarwal, M.D., is a radiologist at Johnston-Willis Hospital and sees brain scans every day. He sees patients with brain trauma routinely and a spectrum of brain injuries, from mild to severe. He says, “Mild brain injuries, like seen in athletes, may not initially show any medical imaging (MRI, PET scan, CT scans) abnormalities. However, more severe head injuries show hemorrhaging and swelling in the brain, which is what a concussion is. Brain cells have long, thin connections with other brain cells and to the spinal cord. These connectors are known as axons and dendrites, and they transmit signals throughout the brain and spinal cord. A good way to imagine a concussion is to imagine brain cells as a collection of thin noodles that conduct signals. Now, think about what happens to these bunched-up noodles as you bend or twist them. These noodles begin to break, and the more severe the injury the more noodles break apart. The breaking of these ‘noodles’ is known as diffuse axonal injury. So, over time, a series of small hits continuously damaging brain cells can lead to brain atrophy, which is an overall loss of mass and volume of the brain. This shrinkage of the brain is easily seen on brain scans. All these symptoms and changes of the brain represent CTE.”

The NFL has been adjusting to keep its players safer, but players like Tua Tagovailoa, are still getting life-threatening injuries much too often. Fortunately, technology, medicine, and science are all evolving to further help maintain these athletes’ condition so they can continue to play a sport that entertains millions of people every day.